diff options
Diffstat (limited to 'security/keys')
25 files changed, 7172 insertions, 2106 deletions
diff --git a/security/keys/Kconfig b/security/keys/Kconfig new file mode 100644 index 00000000000..a4f3f8c48d6 --- /dev/null +++ b/security/keys/Kconfig @@ -0,0 +1,100 @@ +# +# Key management configuration +# + +config KEYS + bool "Enable access key retention support" + select ASSOCIATIVE_ARRAY + help + This option provides support for retaining authentication tokens and + access keys in the kernel. + + It also includes provision of methods by which such keys might be + associated with a process so that network filesystems, encryption + support and the like can find them. + + Furthermore, a special type of key is available that acts as keyring: + a searchable sequence of keys. Each process is equipped with access + to five standard keyrings: UID-specific, GID-specific, session, + process and thread. + + If you are unsure as to whether this is required, answer N. + +config PERSISTENT_KEYRINGS + bool "Enable register of persistent per-UID keyrings" + depends on KEYS + help + This option provides a register of persistent per-UID keyrings, + primarily aimed at Kerberos key storage. The keyrings are persistent + in the sense that they stay around after all processes of that UID + have exited, not that they survive the machine being rebooted. + + A particular keyring may be accessed by either the user whose keyring + it is or by a process with administrative privileges. The active + LSMs gets to rule on which admin-level processes get to access the + cache. + + Keyrings are created and added into the register upon demand and get + removed if they expire (a default timeout is set upon creation). + +config BIG_KEYS + bool "Large payload keys" + depends on KEYS + depends on TMPFS + help + This option provides support for holding large keys within the kernel + (for example Kerberos ticket caches). The data may be stored out to + swapspace by tmpfs. + + If you are unsure as to whether this is required, answer N. + +config TRUSTED_KEYS + tristate "TRUSTED KEYS" + depends on KEYS && TCG_TPM + select CRYPTO + select CRYPTO_HMAC + select CRYPTO_SHA1 + help + This option provides support for creating, sealing, and unsealing + keys in the kernel. Trusted keys are random number symmetric keys, + generated and RSA-sealed by the TPM. The TPM only unseals the keys, + if the boot PCRs and other criteria match. Userspace will only ever + see encrypted blobs. + + If you are unsure as to whether this is required, answer N. + +config ENCRYPTED_KEYS + tristate "ENCRYPTED KEYS" + depends on KEYS + select CRYPTO + select CRYPTO_HMAC + select CRYPTO_AES + select CRYPTO_CBC + select CRYPTO_SHA256 + select CRYPTO_RNG + help + This option provides support for create/encrypting/decrypting keys + in the kernel. Encrypted keys are kernel generated random numbers, + which are encrypted/decrypted with a 'master' symmetric key. The + 'master' key can be either a trusted-key or user-key type. + Userspace only ever sees/stores encrypted blobs. + + If you are unsure as to whether this is required, answer N. + +config KEYS_DEBUG_PROC_KEYS + bool "Enable the /proc/keys file by which keys may be viewed" + depends on KEYS + help + This option turns on support for the /proc/keys file - through which + can be listed all the keys on the system that are viewable by the + reading process. + + The only keys included in the list are those that grant View + permission to the reading process whether or not it possesses them. + Note that LSM security checks are still performed, and may further + filter out keys that the current process is not authorised to view. + + Only key attributes are listed here; key payloads are not included in + the resulting table. + + If you are unsure as to whether this is required, answer N. diff --git a/security/keys/Makefile b/security/keys/Makefile index 5145adfb6a0..dfb3a7beded 100644 --- a/security/keys/Makefile +++ b/security/keys/Makefile @@ -2,7 +2,11 @@ # Makefile for key management # +# +# Core +# obj-y := \ + gc.o \ key.o \ keyring.o \ keyctl.o \ @@ -11,6 +15,14 @@ obj-y := \ request_key.o \ request_key_auth.o \ user_defined.o - obj-$(CONFIG_KEYS_COMPAT) += compat.o obj-$(CONFIG_PROC_FS) += proc.o +obj-$(CONFIG_SYSCTL) += sysctl.o +obj-$(CONFIG_PERSISTENT_KEYRINGS) += persistent.o + +# +# Key types +# +obj-$(CONFIG_BIG_KEYS) += big_key.o +obj-$(CONFIG_TRUSTED_KEYS) += trusted.o +obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys/ diff --git a/security/keys/big_key.c b/security/keys/big_key.c new file mode 100644 index 00000000000..8137b27d641 --- /dev/null +++ b/security/keys/big_key.c @@ -0,0 +1,207 @@ +/* Large capacity key type + * + * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/seq_file.h> +#include <linux/file.h> +#include <linux/shmem_fs.h> +#include <linux/err.h> +#include <keys/user-type.h> +#include <keys/big_key-type.h> + +MODULE_LICENSE("GPL"); + +/* + * If the data is under this limit, there's no point creating a shm file to + * hold it as the permanently resident metadata for the shmem fs will be at + * least as large as the data. + */ +#define BIG_KEY_FILE_THRESHOLD (sizeof(struct inode) + sizeof(struct dentry)) + +/* + * big_key defined keys take an arbitrary string as the description and an + * arbitrary blob of data as the payload + */ +struct key_type key_type_big_key = { + .name = "big_key", + .def_lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, + .instantiate = big_key_instantiate, + .match = user_match, + .revoke = big_key_revoke, + .destroy = big_key_destroy, + .describe = big_key_describe, + .read = big_key_read, +}; + +/* + * Instantiate a big key + */ +int big_key_instantiate(struct key *key, struct key_preparsed_payload *prep) +{ + struct path *path = (struct path *)&key->payload.data2; + struct file *file; + ssize_t written; + size_t datalen = prep->datalen; + int ret; + + ret = -EINVAL; + if (datalen <= 0 || datalen > 1024 * 1024 || !prep->data) + goto error; + + /* Set an arbitrary quota */ + ret = key_payload_reserve(key, 16); + if (ret < 0) + goto error; + + key->type_data.x[1] = datalen; + + if (datalen > BIG_KEY_FILE_THRESHOLD) { + /* Create a shmem file to store the data in. This will permit the data + * to be swapped out if needed. + * + * TODO: Encrypt the stored data with a temporary key. + */ + file = shmem_kernel_file_setup("", datalen, 0); + if (IS_ERR(file)) { + ret = PTR_ERR(file); + goto err_quota; + } + + written = kernel_write(file, prep->data, prep->datalen, 0); + if (written != datalen) { + ret = written; + if (written >= 0) + ret = -ENOMEM; + goto err_fput; + } + + /* Pin the mount and dentry to the key so that we can open it again + * later + */ + *path = file->f_path; + path_get(path); + fput(file); + } else { + /* Just store the data in a buffer */ + void *data = kmalloc(datalen, GFP_KERNEL); + if (!data) { + ret = -ENOMEM; + goto err_quota; + } + + key->payload.data = memcpy(data, prep->data, prep->datalen); + } + return 0; + +err_fput: + fput(file); +err_quota: + key_payload_reserve(key, 0); +error: + return ret; +} + +/* + * dispose of the links from a revoked keyring + * - called with the key sem write-locked + */ +void big_key_revoke(struct key *key) +{ + struct path *path = (struct path *)&key->payload.data2; + + /* clear the quota */ + key_payload_reserve(key, 0); + if (key_is_instantiated(key) && key->type_data.x[1] > BIG_KEY_FILE_THRESHOLD) + vfs_truncate(path, 0); +} + +/* + * dispose of the data dangling from the corpse of a big_key key + */ +void big_key_destroy(struct key *key) +{ + if (key->type_data.x[1] > BIG_KEY_FILE_THRESHOLD) { + struct path *path = (struct path *)&key->payload.data2; + path_put(path); + path->mnt = NULL; + path->dentry = NULL; + } else { + kfree(key->payload.data); + key->payload.data = NULL; + } +} + +/* + * describe the big_key key + */ +void big_key_describe(const struct key *key, struct seq_file *m) +{ + unsigned long datalen = key->type_data.x[1]; + + seq_puts(m, key->description); + + if (key_is_instantiated(key)) + seq_printf(m, ": %lu [%s]", + datalen, + datalen > BIG_KEY_FILE_THRESHOLD ? "file" : "buff"); +} + +/* + * read the key data + * - the key's semaphore is read-locked + */ +long big_key_read(const struct key *key, char __user *buffer, size_t buflen) +{ + unsigned long datalen = key->type_data.x[1]; + long ret; + + if (!buffer || buflen < datalen) + return datalen; + + if (datalen > BIG_KEY_FILE_THRESHOLD) { + struct path *path = (struct path *)&key->payload.data2; + struct file *file; + loff_t pos; + + file = dentry_open(path, O_RDONLY, current_cred()); + if (IS_ERR(file)) + return PTR_ERR(file); + + pos = 0; + ret = vfs_read(file, buffer, datalen, &pos); + fput(file); + if (ret >= 0 && ret != datalen) + ret = -EIO; + } else { + ret = datalen; + if (copy_to_user(buffer, key->payload.data, datalen) != 0) + ret = -EFAULT; + } + + return ret; +} + +/* + * Module stuff + */ +static int __init big_key_init(void) +{ + return register_key_type(&key_type_big_key); +} + +static void __exit big_key_cleanup(void) +{ + unregister_key_type(&key_type_big_key); +} + +module_init(big_key_init); +module_exit(big_key_cleanup); diff --git a/security/keys/compat.c b/security/keys/compat.c index e10ec995f27..347896548ad 100644 --- a/security/keys/compat.c +++ b/security/keys/compat.c @@ -1,4 +1,4 @@ -/* compat.c: 32-bit compatibility syscall for 64-bit systems +/* 32-bit compatibility syscall for 64-bit systems * * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) @@ -12,18 +12,61 @@ #include <linux/syscalls.h> #include <linux/keyctl.h> #include <linux/compat.h> +#include <linux/slab.h> #include "internal.h" -/*****************************************************************************/ /* - * the key control system call, 32-bit compatibility version for 64-bit archs - * - this should only be called if the 64-bit arch uses weird pointers in - * 32-bit mode or doesn't guarantee that the top 32-bits of the argument - * registers on taking a 32-bit syscall are zero - * - if you can, you should call sys_keyctl directly + * Instantiate a key with the specified compatibility multipart payload and + * link the key into the destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * If successful, 0 will be returned. + */ +static long compat_keyctl_instantiate_key_iov( + key_serial_t id, + const struct compat_iovec __user *_payload_iov, + unsigned ioc, + key_serial_t ringid) +{ + struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; + long ret; + + if (!_payload_iov || !ioc) + goto no_payload; + + ret = compat_rw_copy_check_uvector(WRITE, _payload_iov, ioc, + ARRAY_SIZE(iovstack), + iovstack, &iov); + if (ret < 0) + goto err; + if (ret == 0) + goto no_payload_free; + + ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid); +err: + if (iov != iovstack) + kfree(iov); + return ret; + +no_payload_free: + if (iov != iovstack) + kfree(iov); +no_payload: + return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid); +} + +/* + * The key control system call, 32-bit compatibility version for 64-bit archs + * + * This should only be called if the 64-bit arch uses weird pointers in 32-bit + * mode or doesn't guarantee that the top 32-bits of the argument registers on + * taking a 32-bit syscall are zero. If you can, you should call sys_keyctl() + * directly. */ -asmlinkage long compat_sys_keyctl(u32 option, - u32 arg2, u32 arg3, u32 arg4, u32 arg5) +COMPAT_SYSCALL_DEFINE5(keyctl, u32, option, + u32, arg2, u32, arg3, u32, arg4, u32, arg5) { switch (option) { case KEYCTL_GET_KEYRING_ID: @@ -79,8 +122,26 @@ asmlinkage long compat_sys_keyctl(u32 option, case KEYCTL_ASSUME_AUTHORITY: return keyctl_assume_authority(arg2); + case KEYCTL_GET_SECURITY: + return keyctl_get_security(arg2, compat_ptr(arg3), arg4); + + case KEYCTL_SESSION_TO_PARENT: + return keyctl_session_to_parent(); + + case KEYCTL_REJECT: + return keyctl_reject_key(arg2, arg3, arg4, arg5); + + case KEYCTL_INSTANTIATE_IOV: + return compat_keyctl_instantiate_key_iov( + arg2, compat_ptr(arg3), arg4, arg5); + + case KEYCTL_INVALIDATE: + return keyctl_invalidate_key(arg2); + + case KEYCTL_GET_PERSISTENT: + return keyctl_get_persistent(arg2, arg3); + default: return -EOPNOTSUPP; } - -} /* end compat_sys_keyctl() */ +} diff --git a/security/keys/encrypted-keys/Makefile b/security/keys/encrypted-keys/Makefile new file mode 100644 index 00000000000..d6f8433250a --- /dev/null +++ b/security/keys/encrypted-keys/Makefile @@ -0,0 +1,10 @@ +# +# Makefile for encrypted keys +# + +obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys.o + +encrypted-keys-y := encrypted.o ecryptfs_format.o +masterkey-$(CONFIG_TRUSTED_KEYS) := masterkey_trusted.o +masterkey-$(CONFIG_TRUSTED_KEYS)-$(CONFIG_ENCRYPTED_KEYS) := masterkey_trusted.o +encrypted-keys-y += $(masterkey-y) $(masterkey-m-m) diff --git a/security/keys/encrypted-keys/ecryptfs_format.c b/security/keys/encrypted-keys/ecryptfs_format.c new file mode 100644 index 00000000000..6daa3b6ff9e --- /dev/null +++ b/security/keys/encrypted-keys/ecryptfs_format.c @@ -0,0 +1,81 @@ +/* + * ecryptfs_format.c: helper functions for the encrypted key type + * + * Copyright (C) 2006 International Business Machines Corp. + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- http://security.polito.it + * + * Authors: + * Michael A. Halcrow <mahalcro@us.ibm.com> + * Tyler Hicks <tyhicks@ou.edu> + * Roberto Sassu <roberto.sassu@polito.it> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + */ + +#include <linux/module.h> +#include "ecryptfs_format.h" + +u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok) +{ + return auth_tok->token.password.session_key_encryption_key; +} +EXPORT_SYMBOL(ecryptfs_get_auth_tok_key); + +/* + * ecryptfs_get_versions() + * + * Source code taken from the software 'ecryptfs-utils' version 83. + * + */ +void ecryptfs_get_versions(int *major, int *minor, int *file_version) +{ + *major = ECRYPTFS_VERSION_MAJOR; + *minor = ECRYPTFS_VERSION_MINOR; + if (file_version) + *file_version = ECRYPTFS_SUPPORTED_FILE_VERSION; +} +EXPORT_SYMBOL(ecryptfs_get_versions); + +/* + * ecryptfs_fill_auth_tok - fill the ecryptfs_auth_tok structure + * + * Fill the ecryptfs_auth_tok structure with required ecryptfs data. + * The source code is inspired to the original function generate_payload() + * shipped with the software 'ecryptfs-utils' version 83. + * + */ +int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok, + const char *key_desc) +{ + int major, minor; + + ecryptfs_get_versions(&major, &minor, NULL); + auth_tok->version = (((uint16_t)(major << 8) & 0xFF00) + | ((uint16_t)minor & 0x00FF)); + auth_tok->token_type = ECRYPTFS_PASSWORD; + strncpy((char *)auth_tok->token.password.signature, key_desc, + ECRYPTFS_PASSWORD_SIG_SIZE); + auth_tok->token.password.session_key_encryption_key_bytes = + ECRYPTFS_MAX_KEY_BYTES; + /* + * Removed auth_tok->token.password.salt and + * auth_tok->token.password.session_key_encryption_key + * initialization from the original code + */ + /* TODO: Make the hash parameterizable via policy */ + auth_tok->token.password.flags |= + ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET; + /* The kernel code will encrypt the session key. */ + auth_tok->session_key.encrypted_key[0] = 0; + auth_tok->session_key.encrypted_key_size = 0; + /* Default; subject to change by kernel eCryptfs */ + auth_tok->token.password.hash_algo = PGP_DIGEST_ALGO_SHA512; + auth_tok->token.password.flags &= ~(ECRYPTFS_PERSISTENT_PASSWORD); + return 0; +} +EXPORT_SYMBOL(ecryptfs_fill_auth_tok); + +MODULE_LICENSE("GPL"); diff --git a/security/keys/encrypted-keys/ecryptfs_format.h b/security/keys/encrypted-keys/ecryptfs_format.h new file mode 100644 index 00000000000..40294de238b --- /dev/null +++ b/security/keys/encrypted-keys/ecryptfs_format.h @@ -0,0 +1,30 @@ +/* + * ecryptfs_format.h: helper functions for the encrypted key type + * + * Copyright (C) 2006 International Business Machines Corp. + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- http://security.polito.it + * + * Authors: + * Michael A. Halcrow <mahalcro@us.ibm.com> + * Tyler Hicks <tyhicks@ou.edu> + * Roberto Sassu <roberto.sassu@polito.it> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + */ + +#ifndef __KEYS_ECRYPTFS_H +#define __KEYS_ECRYPTFS_H + +#include <linux/ecryptfs.h> + +#define PGP_DIGEST_ALGO_SHA512 10 + +u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok); +void ecryptfs_get_versions(int *major, int *minor, int *file_version); +int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok, + const char *key_desc); + +#endif /* __KEYS_ECRYPTFS_H */ diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c new file mode 100644 index 00000000000..5fe443d120a --- /dev/null +++ b/security/keys/encrypted-keys/encrypted.c @@ -0,0 +1,1040 @@ +/* + * Copyright (C) 2010 IBM Corporation + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- http://security.polito.it + * + * Authors: + * Mimi Zohar <zohar@us.ibm.com> + * Roberto Sassu <roberto.sassu@polito.it> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + * + * See Documentation/security/keys-trusted-encrypted.txt + */ + +#include <linux/uaccess.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/parser.h> +#include <linux/string.h> +#include <linux/err.h> +#include <keys/user-type.h> +#include <keys/trusted-type.h> +#include <keys/encrypted-type.h> +#include <linux/key-type.h> +#include <linux/random.h> +#include <linux/rcupdate.h> +#include <linux/scatterlist.h> +#include <linux/crypto.h> +#include <linux/ctype.h> +#include <crypto/hash.h> +#include <crypto/sha.h> +#include <crypto/aes.h> + +#include "encrypted.h" +#include "ecryptfs_format.h" + +static const char KEY_TRUSTED_PREFIX[] = "trusted:"; +static const char KEY_USER_PREFIX[] = "user:"; +static const char hash_alg[] = "sha256"; +static const char hmac_alg[] = "hmac(sha256)"; +static const char blkcipher_alg[] = "cbc(aes)"; +static const char key_format_default[] = "default"; +static const char key_format_ecryptfs[] = "ecryptfs"; +static unsigned int ivsize; +static int blksize; + +#define KEY_TRUSTED_PREFIX_LEN (sizeof (KEY_TRUSTED_PREFIX) - 1) +#define KEY_USER_PREFIX_LEN (sizeof (KEY_USER_PREFIX) - 1) +#define KEY_ECRYPTFS_DESC_LEN 16 +#define HASH_SIZE SHA256_DIGEST_SIZE +#define MAX_DATA_SIZE 4096 +#define MIN_DATA_SIZE 20 + +struct sdesc { + struct shash_desc shash; + char ctx[]; +}; + +static struct crypto_shash *hashalg; +static struct crypto_shash *hmacalg; + +enum { + Opt_err = -1, Opt_new, Opt_load, Opt_update +}; + +enum { + Opt_error = -1, Opt_default, Opt_ecryptfs +}; + +static const match_table_t key_format_tokens = { + {Opt_default, "default"}, + {Opt_ecryptfs, "ecryptfs"}, + {Opt_error, NULL} +}; + +static const match_table_t key_tokens = { + {Opt_new, "new"}, + {Opt_load, "load"}, + {Opt_update, "update"}, + {Opt_err, NULL} +}; + +static int aes_get_sizes(void) +{ + struct crypto_blkcipher *tfm; + + tfm = crypto_alloc_blkcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(tfm)) { + pr_err("encrypted_key: failed to alloc_cipher (%ld)\n", + PTR_ERR(tfm)); + return PTR_ERR(tfm); + } + ivsize = crypto_blkcipher_ivsize(tfm); + blksize = crypto_blkcipher_blocksize(tfm); + crypto_free_blkcipher(tfm); + return 0; +} + +/* + * valid_ecryptfs_desc - verify the description of a new/loaded encrypted key + * + * The description of a encrypted key with format 'ecryptfs' must contain + * exactly 16 hexadecimal characters. + * + */ +static int valid_ecryptfs_desc(const char *ecryptfs_desc) +{ + int i; + + if (strlen(ecryptfs_desc) != KEY_ECRYPTFS_DESC_LEN) { + pr_err("encrypted_key: key description must be %d hexadecimal " + "characters long\n", KEY_ECRYPTFS_DESC_LEN); + return -EINVAL; + } + + for (i = 0; i < KEY_ECRYPTFS_DESC_LEN; i++) { + if (!isxdigit(ecryptfs_desc[i])) { + pr_err("encrypted_key: key description must contain " + "only hexadecimal characters\n"); + return -EINVAL; + } + } + + return 0; +} + +/* + * valid_master_desc - verify the 'key-type:desc' of a new/updated master-key + * + * key-type:= "trusted:" | "user:" + * desc:= master-key description + * + * Verify that 'key-type' is valid and that 'desc' exists. On key update, + * only the master key description is permitted to change, not the key-type. + * The key-type remains constant. + * + * On success returns 0, otherwise -EINVAL. + */ +static int valid_master_desc(const char *new_desc, const char *orig_desc) +{ + if (!memcmp(new_desc, KEY_TRUSTED_PREFIX, KEY_TRUSTED_PREFIX_LEN)) { + if (strlen(new_desc) == KEY_TRUSTED_PREFIX_LEN) + goto out; + if (orig_desc) + if (memcmp(new_desc, orig_desc, KEY_TRUSTED_PREFIX_LEN)) + goto out; + } else if (!memcmp(new_desc, KEY_USER_PREFIX, KEY_USER_PREFIX_LEN)) { + if (strlen(new_desc) == KEY_USER_PREFIX_LEN) + goto out; + if (orig_desc) + if (memcmp(new_desc, orig_desc, KEY_USER_PREFIX_LEN)) + goto out; + } else + goto out; + return 0; +out: + return -EINVAL; +} + +/* + * datablob_parse - parse the keyctl data + * + * datablob format: + * new [<format>] <master-key name> <decrypted data length> + * load [<format>] <master-key name> <decrypted data length> + * <encrypted iv + data> + * update <new-master-key name> + * + * Tokenizes a copy of the keyctl data, returning a pointer to each token, + * which is null terminated. + * + * On success returns 0, otherwise -EINVAL. + */ +static int datablob_parse(char *datablob, const char **format, + char **master_desc, char **decrypted_datalen, + char **hex_encoded_iv) +{ + substring_t args[MAX_OPT_ARGS]; + int ret = -EINVAL; + int key_cmd; + int key_format; + char *p, *keyword; + + keyword = strsep(&datablob, " \t"); + if (!keyword) { + pr_info("encrypted_key: insufficient parameters specified\n"); + return ret; + } + key_cmd = match_token(keyword, key_tokens, args); + + /* Get optional format: default | ecryptfs */ + p = strsep(&datablob, " \t"); + if (!p) { + pr_err("encrypted_key: insufficient parameters specified\n"); + return ret; + } + + key_format = match_token(p, key_format_tokens, args); + switch (key_format) { + case Opt_ecryptfs: + case Opt_default: + *format = p; + *master_desc = strsep(&datablob, " \t"); + break; + case Opt_error: + *master_desc = p; + break; + } + + if (!*master_desc) { + pr_info("encrypted_key: master key parameter is missing\n"); + goto out; + } + + if (valid_master_desc(*master_desc, NULL) < 0) { + pr_info("encrypted_key: master key parameter \'%s\' " + "is invalid\n", *master_desc); + goto out; + } + + if (decrypted_datalen) { + *decrypted_datalen = strsep(&datablob, " \t"); + if (!*decrypted_datalen) { + pr_info("encrypted_key: keylen parameter is missing\n"); + goto out; + } + } + + switch (key_cmd) { + case Opt_new: + if (!decrypted_datalen) { + pr_info("encrypted_key: keyword \'%s\' not allowed " + "when called from .update method\n", keyword); + break; + } + ret = 0; + break; + case Opt_load: + if (!decrypted_datalen) { + pr_info("encrypted_key: keyword \'%s\' not allowed " + "when called from .update method\n", keyword); + break; + } + *hex_encoded_iv = strsep(&datablob, " \t"); + if (!*hex_encoded_iv) { + pr_info("encrypted_key: hex blob is missing\n"); + break; + } + ret = 0; + break; + case Opt_update: + if (decrypted_datalen) { + pr_info("encrypted_key: keyword \'%s\' not allowed " + "when called from .instantiate method\n", + keyword); + break; + } + ret = 0; + break; + case Opt_err: + pr_info("encrypted_key: keyword \'%s\' not recognized\n", + keyword); + break; + } +out: + return ret; +} + +/* + * datablob_format - format as an ascii string, before copying to userspace + */ +static char *datablob_format(struct encrypted_key_payload *epayload, + size_t asciiblob_len) +{ + char *ascii_buf, *bufp; + u8 *iv = epayload->iv; + int len; + int i; + + ascii_buf = kmalloc(asciiblob_len + 1, GFP_KERNEL); + if (!ascii_buf) + goto out; + + ascii_buf[asciiblob_len] = '\0'; + + /* copy datablob master_desc and datalen strings */ + len = sprintf(ascii_buf, "%s %s %s ", epayload->format, + epayload->master_desc, epayload->datalen); + + /* convert the hex encoded iv, encrypted-data and HMAC to ascii */ + bufp = &ascii_buf[len]; + for (i = 0; i < (asciiblob_len - len) / 2; i++) + bufp = hex_byte_pack(bufp, iv[i]); +out: + return ascii_buf; +} + +/* + * request_user_key - request the user key + * + * Use a user provided key to encrypt/decrypt an encrypted-key. + */ +static struct key *request_user_key(const char *master_desc, u8 **master_key, + size_t *master_keylen) +{ + struct user_key_payload *upayload; + struct key *ukey; + + ukey = request_key(&key_type_user, master_desc, NULL); + if (IS_ERR(ukey)) + goto error; + + down_read(&ukey->sem); + upayload = ukey->payload.data; + *master_key = upayload->data; + *master_keylen = upayload->datalen; +error: + return ukey; +} + +static struct sdesc *alloc_sdesc(struct crypto_shash *alg) +{ + struct sdesc *sdesc; + int size; + + size = sizeof(struct shash_desc) + crypto_shash_descsize(alg); + sdesc = kmalloc(size, GFP_KERNEL); + if (!sdesc) + return ERR_PTR(-ENOMEM); + sdesc->shash.tfm = alg; + sdesc->shash.flags = 0x0; + return sdesc; +} + +static int calc_hmac(u8 *digest, const u8 *key, unsigned int keylen, + const u8 *buf, unsigned int buflen) +{ + struct sdesc *sdesc; + int ret; + + sdesc = alloc_sdesc(hmacalg); + if (IS_ERR(sdesc)) { + pr_info("encrypted_key: can't alloc %s\n", hmac_alg); + return PTR_ERR(sdesc); + } + + ret = crypto_shash_setkey(hmacalg, key, keylen); + if (!ret) + ret = crypto_shash_digest(&sdesc->shash, buf, buflen, digest); + kfree(sdesc); + return ret; +} + +static int calc_hash(u8 *digest, const u8 *buf, unsigned int buflen) +{ + struct sdesc *sdesc; + int ret; + + sdesc = alloc_sdesc(hashalg); + if (IS_ERR(sdesc)) { + pr_info("encrypted_key: can't alloc %s\n", hash_alg); + return PTR_ERR(sdesc); + } + + ret = crypto_shash_digest(&sdesc->shash, buf, buflen, digest); + kfree(sdesc); + return ret; +} + +enum derived_key_type { ENC_KEY, AUTH_KEY }; + +/* Derive authentication/encryption key from trusted key */ +static int get_derived_key(u8 *derived_key, enum derived_key_type key_type, + const u8 *master_key, size_t master_keylen) +{ + u8 *derived_buf; + unsigned int derived_buf_len; + int ret; + + derived_buf_len = strlen("AUTH_KEY") + 1 + master_keylen; + if (derived_buf_len < HASH_SIZE) + derived_buf_len = HASH_SIZE; + + derived_buf = kzalloc(derived_buf_len, GFP_KERNEL); + if (!derived_buf) { + pr_err("encrypted_key: out of memory\n"); + return -ENOMEM; + } + if (key_type) + strcpy(derived_buf, "AUTH_KEY"); + else + strcpy(derived_buf, "ENC_KEY"); + + memcpy(derived_buf + strlen(derived_buf) + 1, master_key, + master_keylen); + ret = calc_hash(derived_key, derived_buf, derived_buf_len); + kfree(derived_buf); + return ret; +} + +static int init_blkcipher_desc(struct blkcipher_desc *desc, const u8 *key, + unsigned int key_len, const u8 *iv, + unsigned int ivsize) +{ + int ret; + + desc->tfm = crypto_alloc_blkcipher(blkcipher_alg, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(desc->tfm)) { + pr_err("encrypted_key: failed to load %s transform (%ld)\n", + blkcipher_alg, PTR_ERR(desc->tfm)); + return PTR_ERR(desc->tfm); + } + desc->flags = 0; + + ret = crypto_blkcipher_setkey(desc->tfm, key, key_len); + if (ret < 0) { + pr_err("encrypted_key: failed to setkey (%d)\n", ret); + crypto_free_blkcipher(desc->tfm); + return ret; + } + crypto_blkcipher_set_iv(desc->tfm, iv, ivsize); + return 0; +} + +static struct key *request_master_key(struct encrypted_key_payload *epayload, + u8 **master_key, size_t *master_keylen) +{ + struct key *mkey = NULL; + + if (!strncmp(epayload->master_desc, KEY_TRUSTED_PREFIX, + KEY_TRUSTED_PREFIX_LEN)) { + mkey = request_trusted_key(epayload->master_desc + + KEY_TRUSTED_PREFIX_LEN, + master_key, master_keylen); + } else if (!strncmp(epayload->master_desc, KEY_USER_PREFIX, + KEY_USER_PREFIX_LEN)) { + mkey = request_user_key(epayload->master_desc + + KEY_USER_PREFIX_LEN, + master_key, master_keylen); + } else + goto out; + + if (IS_ERR(mkey)) { + int ret = PTR_ERR(mkey); + + if (ret == -ENOTSUPP) + pr_info("encrypted_key: key %s not supported", + epayload->master_desc); + else + pr_info("encrypted_key: key %s not found", + epayload->master_desc); + goto out; + } + + dump_master_key(*master_key, *master_keylen); +out: + return mkey; +} + +/* Before returning data to userspace, encrypt decrypted data. */ +static int derived_key_encrypt(struct encrypted_key_payload *epayload, + const u8 *derived_key, + unsigned int derived_keylen) +{ + struct scatterlist sg_in[2]; + struct scatterlist sg_out[1]; + struct blkcipher_desc desc; + unsigned int encrypted_datalen; + unsigned int padlen; + char pad[16]; + int ret; + + encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); + padlen = encrypted_datalen - epayload->decrypted_datalen; + + ret = init_blkcipher_desc(&desc, derived_key, derived_keylen, + epayload->iv, ivsize); + if (ret < 0) + goto out; + dump_decrypted_data(epayload); + + memset(pad, 0, sizeof pad); + sg_init_table(sg_in, 2); + sg_set_buf(&sg_in[0], epayload->decrypted_data, + epayload->decrypted_datalen); + sg_set_buf(&sg_in[1], pad, padlen); + + sg_init_table(sg_out, 1); + sg_set_buf(sg_out, epayload->encrypted_data, encrypted_datalen); + + ret = crypto_blkcipher_encrypt(&desc, sg_out, sg_in, encrypted_datalen); + crypto_free_blkcipher(desc.tfm); + if (ret < 0) + pr_err("encrypted_key: failed to encrypt (%d)\n", ret); + else + dump_encrypted_data(epayload, encrypted_datalen); +out: + return ret; +} + +static int datablob_hmac_append(struct encrypted_key_payload *epayload, + const u8 *master_key, size_t master_keylen) +{ + u8 derived_key[HASH_SIZE]; + u8 *digest; + int ret; + + ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen); + if (ret < 0) + goto out; + + digest = epayload->format + epayload->datablob_len; + ret = calc_hmac(digest, derived_key, sizeof derived_key, + epayload->format, epayload->datablob_len); + if (!ret) + dump_hmac(NULL, digest, HASH_SIZE); +out: + return ret; +} + +/* verify HMAC before decrypting encrypted key */ +static int datablob_hmac_verify(struct encrypted_key_payload *epayload, + const u8 *format, const u8 *master_key, + size_t master_keylen) +{ + u8 derived_key[HASH_SIZE]; + u8 digest[HASH_SIZE]; + int ret; + char *p; + unsigned short len; + + ret = get_derived_key(derived_key, AUTH_KEY, master_key, master_keylen); + if (ret < 0) + goto out; + + len = epayload->datablob_len; + if (!format) { + p = epayload->master_desc; + len -= strlen(epayload->format) + 1; + } else + p = epayload->format; + + ret = calc_hmac(digest, derived_key, sizeof derived_key, p, len); + if (ret < 0) + goto out; + ret = memcmp(digest, epayload->format + epayload->datablob_len, + sizeof digest); + if (ret) { + ret = -EINVAL; + dump_hmac("datablob", + epayload->format + epayload->datablob_len, + HASH_SIZE); + dump_hmac("calc", digest, HASH_SIZE); + } +out: + return ret; +} + +static int derived_key_decrypt(struct encrypted_key_payload *epayload, + const u8 *derived_key, + unsigned int derived_keylen) +{ + struct scatterlist sg_in[1]; + struct scatterlist sg_out[2]; + struct blkcipher_desc desc; + unsigned int encrypted_datalen; + char pad[16]; + int ret; + + encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); + ret = init_blkcipher_desc(&desc, derived_key, derived_keylen, + epayload->iv, ivsize); + if (ret < 0) + goto out; + dump_encrypted_data(epayload, encrypted_datalen); + + memset(pad, 0, sizeof pad); + sg_init_table(sg_in, 1); + sg_init_table(sg_out, 2); + sg_set_buf(sg_in, epayload->encrypted_data, encrypted_datalen); + sg_set_buf(&sg_out[0], epayload->decrypted_data, + epayload->decrypted_datalen); + sg_set_buf(&sg_out[1], pad, sizeof pad); + + ret = crypto_blkcipher_decrypt(&desc, sg_out, sg_in, encrypted_datalen); + crypto_free_blkcipher(desc.tfm); + if (ret < 0) + goto out; + dump_decrypted_data(epayload); +out: + return ret; +} + +/* Allocate memory for decrypted key and datablob. */ +static struct encrypted_key_payload *encrypted_key_alloc(struct key *key, + const char *format, + const char *master_desc, + const char *datalen) +{ + struct encrypted_key_payload *epayload = NULL; + unsigned short datablob_len; + unsigned short decrypted_datalen; + unsigned short payload_datalen; + unsigned int encrypted_datalen; + unsigned int format_len; + long dlen; + int ret; + + ret = kstrtol(datalen, 10, &dlen); + if (ret < 0 || dlen < MIN_DATA_SIZE || dlen > MAX_DATA_SIZE) + return ERR_PTR(-EINVAL); + + format_len = (!format) ? strlen(key_format_default) : strlen(format); + decrypted_datalen = dlen; + payload_datalen = decrypted_datalen; + if (format && !strcmp(format, key_format_ecryptfs)) { + if (dlen != ECRYPTFS_MAX_KEY_BYTES) { + pr_err("encrypted_key: keylen for the ecryptfs format " + "must be equal to %d bytes\n", + ECRYPTFS_MAX_KEY_BYTES); + return ERR_PTR(-EINVAL); + } + decrypted_datalen = ECRYPTFS_MAX_KEY_BYTES; + payload_datalen = sizeof(struct ecryptfs_auth_tok); + } + + encrypted_datalen = roundup(decrypted_datalen, blksize); + + datablob_len = format_len + 1 + strlen(master_desc) + 1 + + strlen(datalen) + 1 + ivsize + 1 + encrypted_datalen; + + ret = key_payload_reserve(key, payload_datalen + datablob_len + + HASH_SIZE + 1); + if (ret < 0) + return ERR_PTR(ret); + + epayload = kzalloc(sizeof(*epayload) + payload_datalen + + datablob_len + HASH_SIZE + 1, GFP_KERNEL); + if (!epayload) + return ERR_PTR(-ENOMEM); + + epayload->payload_datalen = payload_datalen; + epayload->decrypted_datalen = decrypted_datalen; + epayload->datablob_len = datablob_len; + return epayload; +} + +static int encrypted_key_decrypt(struct encrypted_key_payload *epayload, + const char *format, const char *hex_encoded_iv) +{ + struct key *mkey; + u8 derived_key[HASH_SIZE]; + u8 *master_key; + u8 *hmac; + const char *hex_encoded_data; + unsigned int encrypted_datalen; + size_t master_keylen; + size_t asciilen; + int ret; + + encrypted_datalen = roundup(epayload->decrypted_datalen, blksize); + asciilen = (ivsize + 1 + encrypted_datalen + HASH_SIZE) * 2; + if (strlen(hex_encoded_iv) != asciilen) + return -EINVAL; + + hex_encoded_data = hex_encoded_iv + (2 * ivsize) + 2; + ret = hex2bin(epayload->iv, hex_encoded_iv, ivsize); + if (ret < 0) + return -EINVAL; + ret = hex2bin(epayload->encrypted_data, hex_encoded_data, + encrypted_datalen); + if (ret < 0) + return -EINVAL; + + hmac = epayload->format + epayload->datablob_len; + ret = hex2bin(hmac, hex_encoded_data + (encrypted_datalen * 2), + HASH_SIZE); + if (ret < 0) + return -EINVAL; + + mkey = request_master_key(epayload, &master_key, &master_keylen); + if (IS_ERR(mkey)) + return PTR_ERR(mkey); + + ret = datablob_hmac_verify(epayload, format, master_key, master_keylen); + if (ret < 0) { + pr_err("encrypted_key: bad hmac (%d)\n", ret); + goto out; + } + + ret = get_derived_key(derived_key, ENC_KEY, master_key, master_keylen); + if (ret < 0) + goto out; + + ret = derived_key_decrypt(epayload, derived_key, sizeof derived_key); + if (ret < 0) + pr_err("encrypted_key: failed to decrypt key (%d)\n", ret); +out: + up_read(&mkey->sem); + key_put(mkey); + return ret; +} + +static void __ekey_init(struct encrypted_key_payload *epayload, + const char *format, const char *master_desc, + const char *datalen) +{ + unsigned int format_len; + + format_len = (!format) ? strlen(key_format_default) : strlen(format); + epayload->format = epayload->payload_data + epayload->payload_datalen; + epayload->master_desc = epayload->format + format_len + 1; + epayload->datalen = epayload->master_desc + strlen(master_desc) + 1; + epayload->iv = epayload->datalen + strlen(datalen) + 1; + epayload->encrypted_data = epayload->iv + ivsize + 1; + epayload->decrypted_data = epayload->payload_data; + + if (!format) + memcpy(epayload->format, key_format_default, format_len); + else { + if (!strcmp(format, key_format_ecryptfs)) + epayload->decrypted_data = + ecryptfs_get_auth_tok_key((struct ecryptfs_auth_tok *)epayload->payload_data); + + memcpy(epayload->format, format, format_len); + } + + memcpy(epayload->master_desc, master_desc, strlen(master_desc)); + memcpy(epayload->datalen, datalen, strlen(datalen)); +} + +/* + * encrypted_init - initialize an encrypted key + * + * For a new key, use a random number for both the iv and data + * itself. For an old key, decrypt the hex encoded data. + */ +static int encrypted_init(struct encrypted_key_payload *epayload, + const char *key_desc, const char *format, + const char *master_desc, const char *datalen, + const char *hex_encoded_iv) +{ + int ret = 0; + + if (format && !strcmp(format, key_format_ecryptfs)) { + ret = valid_ecryptfs_desc(key_desc); + if (ret < 0) + return ret; + + ecryptfs_fill_auth_tok((struct ecryptfs_auth_tok *)epayload->payload_data, + key_desc); + } + + __ekey_init(epayload, format, master_desc, datalen); + if (!hex_encoded_iv) { + get_random_bytes(epayload->iv, ivsize); + + get_random_bytes(epayload->decrypted_data, + epayload->decrypted_datalen); + } else + ret = encrypted_key_decrypt(epayload, format, hex_encoded_iv); + return ret; +} + +/* + * encrypted_instantiate - instantiate an encrypted key + * + * Decrypt an existing encrypted datablob or create a new encrypted key + * based on a kernel random number. + * + * On success, return 0. Otherwise return errno. + */ +static int encrypted_instantiate(struct key *key, + struct key_preparsed_payload *prep) +{ + struct encrypted_key_payload *epayload = NULL; + char *datablob = NULL; + const char *format = NULL; + char *master_desc = NULL; + char *decrypted_datalen = NULL; + char *hex_encoded_iv = NULL; + size_t datalen = prep->datalen; + int ret; + + if (datalen <= 0 || datalen > 32767 || !prep->data) + return -EINVAL; + + datablob = kmalloc(datalen + 1, GFP_KERNEL); + if (!datablob) + return -ENOMEM; + datablob[datalen] = 0; + memcpy(datablob, prep->data, datalen); + ret = datablob_parse(datablob, &format, &master_desc, + &decrypted_datalen, &hex_encoded_iv); + if (ret < 0) + goto out; + + epayload = encrypted_key_alloc(key, format, master_desc, + decrypted_datalen); + if (IS_ERR(epayload)) { + ret = PTR_ERR(epayload); + goto out; + } + ret = encrypted_init(epayload, key->description, format, master_desc, + decrypted_datalen, hex_encoded_iv); + if (ret < 0) { + kfree(epayload); + goto out; + } + + rcu_assign_keypointer(key, epayload); +out: + kfree(datablob); + return ret; +} + +static void encrypted_rcu_free(struct rcu_head *rcu) +{ + struct encrypted_key_payload *epayload; + + epayload = container_of(rcu, struct encrypted_key_payload, rcu); + memset(epayload->decrypted_data, 0, epayload->decrypted_datalen); + kfree(epayload); +} + +/* + * encrypted_update - update the master key description + * + * Change the master key description for an existing encrypted key. + * The next read will return an encrypted datablob using the new + * master key description. + * + * On success, return 0. Otherwise return errno. + */ +static int encrypted_update(struct key *key, struct key_preparsed_payload *prep) +{ + struct encrypted_key_payload *epayload = key->payload.data; + struct encrypted_key_payload *new_epayload; + char *buf; + char *new_master_desc = NULL; + const char *format = NULL; + size_t datalen = prep->datalen; + int ret = 0; + + if (datalen <= 0 || datalen > 32767 || !prep->data) + return -EINVAL; + + buf = kmalloc(datalen + 1, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + buf[datalen] = 0; + memcpy(buf, prep->data, datalen); + ret = datablob_parse(buf, &format, &new_master_desc, NULL, NULL); + if (ret < 0) + goto out; + + ret = valid_master_desc(new_master_desc, epayload->master_desc); + if (ret < 0) + goto out; + + new_epayload = encrypted_key_alloc(key, epayload->format, + new_master_desc, epayload->datalen); + if (IS_ERR(new_epayload)) { + ret = PTR_ERR(new_epayload); + goto out; + } + + __ekey_init(new_epayload, epayload->format, new_master_desc, + epayload->datalen); + + memcpy(new_epayload->iv, epayload->iv, ivsize); + memcpy(new_epayload->payload_data, epayload->payload_data, + epayload->payload_datalen); + + rcu_assign_keypointer(key, new_epayload); + call_rcu(&epayload->rcu, encrypted_rcu_free); +out: + kfree(buf); + return ret; +} + +/* + * encrypted_read - format and copy the encrypted data to userspace + * + * The resulting datablob format is: + * <master-key name> <decrypted data length> <encrypted iv> <encrypted data> + * + * On success, return to userspace the encrypted key datablob size. + */ +static long encrypted_read(const struct key *key, char __user *buffer, + size_t buflen) +{ + struct encrypted_key_payload *epayload; + struct key *mkey; + u8 *master_key; + size_t master_keylen; + char derived_key[HASH_SIZE]; + char *ascii_buf; + size_t asciiblob_len; + int ret; + + epayload = rcu_dereference_key(key); + + /* returns the hex encoded iv, encrypted-data, and hmac as ascii */ + asciiblob_len = epayload->datablob_len + ivsize + 1 + + roundup(epayload->decrypted_datalen, blksize) + + (HASH_SIZE * 2); + + if (!buffer || buflen < asciiblob_len) + return asciiblob_len; + + mkey = request_master_key(epayload, &master_key, &master_keylen); + if (IS_ERR(mkey)) + return PTR_ERR(mkey); + + ret = get_derived_key(derived_key, ENC_KEY, master_key, master_keylen); + if (ret < 0) + goto out; + + ret = derived_key_encrypt(epayload, derived_key, sizeof derived_key); + if (ret < 0) + goto out; + + ret = datablob_hmac_append(epayload, master_key, master_keylen); + if (ret < 0) + goto out; + + ascii_buf = datablob_format(epayload, asciiblob_len); + if (!ascii_buf) { + ret = -ENOMEM; + goto out; + } + + up_read(&mkey->sem); + key_put(mkey); + + if (copy_to_user(buffer, ascii_buf, asciiblob_len) != 0) + ret = -EFAULT; + kfree(ascii_buf); + + return asciiblob_len; +out: + up_read(&mkey->sem); + key_put(mkey); + return ret; +} + +/* + * encrypted_destroy - before freeing the key, clear the decrypted data + * + * Before freeing the key, clear the memory containing the decrypted + * key data. + */ +static void encrypted_destroy(struct key *key) +{ + struct encrypted_key_payload *epayload = key->payload.data; + + if (!epayload) + return; + + memset(epayload->decrypted_data, 0, epayload->decrypted_datalen); + kfree(key->payload.data); +} + +struct key_type key_type_encrypted = { + .name = "encrypted", + .instantiate = encrypted_instantiate, + .update = encrypted_update, + .match = user_match, + .destroy = encrypted_destroy, + .describe = user_describe, + .read = encrypted_read, +}; +EXPORT_SYMBOL_GPL(key_type_encrypted); + +static void encrypted_shash_release(void) +{ + if (hashalg) + crypto_free_shash(hashalg); + if (hmacalg) + crypto_free_shash(hmacalg); +} + +static int __init encrypted_shash_alloc(void) +{ + int ret; + + hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(hmacalg)) { + pr_info("encrypted_key: could not allocate crypto %s\n", + hmac_alg); + return PTR_ERR(hmacalg); + } + + hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(hashalg)) { + pr_info("encrypted_key: could not allocate crypto %s\n", + hash_alg); + ret = PTR_ERR(hashalg); + goto hashalg_fail; + } + + return 0; + +hashalg_fail: + crypto_free_shash(hmacalg); + return ret; +} + +static int __init init_encrypted(void) +{ + int ret; + + ret = encrypted_shash_alloc(); + if (ret < 0) + return ret; + ret = register_key_type(&key_type_encrypted); + if (ret < 0) + goto out; + return aes_get_sizes(); +out: + encrypted_shash_release(); + return ret; + +} + +static void __exit cleanup_encrypted(void) +{ + encrypted_shash_release(); + unregister_key_type(&key_type_encrypted); +} + +late_initcall(init_encrypted); +module_exit(cleanup_encrypted); + +MODULE_LICENSE("GPL"); diff --git a/security/keys/encrypted-keys/encrypted.h b/security/keys/encrypted-keys/encrypted.h new file mode 100644 index 00000000000..8136a2d44c6 --- /dev/null +++ b/security/keys/encrypted-keys/encrypted.h @@ -0,0 +1,66 @@ +#ifndef __ENCRYPTED_KEY_H +#define __ENCRYPTED_KEY_H + +#define ENCRYPTED_DEBUG 0 +#if defined(CONFIG_TRUSTED_KEYS) || \ + (defined(CONFIG_TRUSTED_KEYS_MODULE) && defined(CONFIG_ENCRYPTED_KEYS_MODULE)) +extern struct key *request_trusted_key(const char *trusted_desc, + u8 **master_key, size_t *master_keylen); +#else +static inline struct key *request_trusted_key(const char *trusted_desc, + u8 **master_key, + size_t *master_keylen) +{ + return ERR_PTR(-EOPNOTSUPP); +} +#endif + +#if ENCRYPTED_DEBUG +static inline void dump_master_key(const u8 *master_key, size_t master_keylen) +{ + print_hex_dump(KERN_ERR, "master key: ", DUMP_PREFIX_NONE, 32, 1, + master_key, master_keylen, 0); +} + +static inline void dump_decrypted_data(struct encrypted_key_payload *epayload) +{ + print_hex_dump(KERN_ERR, "decrypted data: ", DUMP_PREFIX_NONE, 32, 1, + epayload->decrypted_data, + epayload->decrypted_datalen, 0); +} + +static inline void dump_encrypted_data(struct encrypted_key_payload *epayload, + unsigned int encrypted_datalen) +{ + print_hex_dump(KERN_ERR, "encrypted data: ", DUMP_PREFIX_NONE, 32, 1, + epayload->encrypted_data, encrypted_datalen, 0); +} + +static inline void dump_hmac(const char *str, const u8 *digest, + unsigned int hmac_size) +{ + if (str) + pr_info("encrypted_key: %s", str); + print_hex_dump(KERN_ERR, "hmac: ", DUMP_PREFIX_NONE, 32, 1, digest, + hmac_size, 0); +} +#else +static inline void dump_master_key(const u8 *master_key, size_t master_keylen) +{ +} + +static inline void dump_decrypted_data(struct encrypted_key_payload *epayload) +{ +} + +static inline void dump_encrypted_data(struct encrypted_key_payload *epayload, + unsigned int encrypted_datalen) +{ +} + +static inline void dump_hmac(const char *str, const u8 *digest, + unsigned int hmac_size) +{ +} +#endif +#endif diff --git a/security/keys/encrypted-keys/masterkey_trusted.c b/security/keys/encrypted-keys/masterkey_trusted.c new file mode 100644 index 00000000000..013f7e5d3a2 --- /dev/null +++ b/security/keys/encrypted-keys/masterkey_trusted.c @@ -0,0 +1,47 @@ +/* + * Copyright (C) 2010 IBM Corporation + * Copyright (C) 2010 Politecnico di Torino, Italy + * TORSEC group -- http://security.polito.it + * + * Authors: + * Mimi Zohar <zohar@us.ibm.com> + * Roberto Sassu <roberto.sassu@polito.it> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + * + * See Documentation/security/keys-trusted-encrypted.txt + */ + +#include <linux/uaccess.h> +#include <linux/module.h> +#include <linux/err.h> +#include <keys/trusted-type.h> +#include <keys/encrypted-type.h> +#include "encrypted.h" + +/* + * request_trusted_key - request the trusted key + * + * Trusted keys are sealed to PCRs and other metadata. Although userspace + * manages both trusted/encrypted key-types, like the encrypted key type + * data, trusted key type data is not visible decrypted from userspace. + */ +struct key *request_trusted_key(const char *trusted_desc, + u8 **master_key, size_t *master_keylen) +{ + struct trusted_key_payload *tpayload; + struct key *tkey; + + tkey = request_key(&key_type_trusted, trusted_desc, NULL); + if (IS_ERR(tkey)) + goto error; + + down_read(&tkey->sem); + tpayload = tkey->payload.data; + *master_key = tpayload->key; + *master_keylen = tpayload->key_len; +error: + return tkey; +} diff --git a/security/keys/gc.c b/security/keys/gc.c new file mode 100644 index 00000000000..d3222b6d7d5 --- /dev/null +++ b/security/keys/gc.c @@ -0,0 +1,367 @@ +/* Key garbage collector + * + * Copyright (C) 2009-2011 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/security.h> +#include <keys/keyring-type.h> +#include "internal.h" + +/* + * Delay between key revocation/expiry in seconds + */ +unsigned key_gc_delay = 5 * 60; + +/* + * Reaper for unused keys. + */ +static void key_garbage_collector(struct work_struct *work); +DECLARE_WORK(key_gc_work, key_garbage_collector); + +/* + * Reaper for links from keyrings to dead keys. + */ +static void key_gc_timer_func(unsigned long); +static DEFINE_TIMER(key_gc_timer, key_gc_timer_func, 0, 0); + +static time_t key_gc_next_run = LONG_MAX; +static struct key_type *key_gc_dead_keytype; + +static unsigned long key_gc_flags; +#define KEY_GC_KEY_EXPIRED 0 /* A key expired and needs unlinking */ +#define KEY_GC_REAP_KEYTYPE 1 /* A keytype is being unregistered */ +#define KEY_GC_REAPING_KEYTYPE 2 /* Cleared when keytype reaped */ + + +/* + * Any key whose type gets unregistered will be re-typed to this if it can't be + * immediately unlinked. + */ +struct key_type key_type_dead = { + .name = "dead", +}; + +/* + * Schedule a garbage collection run. + * - time precision isn't particularly important + */ +void key_schedule_gc(time_t gc_at) +{ + unsigned long expires; + time_t now = current_kernel_time().tv_sec; + + kenter("%ld", gc_at - now); + + if (gc_at <= now || test_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags)) { + kdebug("IMMEDIATE"); + schedule_work(&key_gc_work); + } else if (gc_at < key_gc_next_run) { + kdebug("DEFERRED"); + key_gc_next_run = gc_at; + expires = jiffies + (gc_at - now) * HZ; + mod_timer(&key_gc_timer, expires); + } +} + +/* + * Schedule a dead links collection run. + */ +void key_schedule_gc_links(void) +{ + set_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags); + schedule_work(&key_gc_work); +} + +/* + * Some key's cleanup time was met after it expired, so we need to get the + * reaper to go through a cycle finding expired keys. + */ +static void key_gc_timer_func(unsigned long data) +{ + kenter(""); + key_gc_next_run = LONG_MAX; + key_schedule_gc_links(); +} + +/* + * wait_on_bit() sleep function for uninterruptible waiting + */ +static int key_gc_wait_bit(void *flags) +{ + schedule(); + return 0; +} + +/* + * Reap keys of dead type. + * + * We use three flags to make sure we see three complete cycles of the garbage + * collector: the first to mark keys of that type as being dead, the second to + * collect dead links and the third to clean up the dead keys. We have to be + * careful as there may already be a cycle in progress. + * + * The caller must be holding key_types_sem. + */ +void key_gc_keytype(struct key_type *ktype) +{ + kenter("%s", ktype->name); + + key_gc_dead_keytype = ktype; + set_bit(KEY_GC_REAPING_KEYTYPE, &key_gc_flags); + smp_mb(); + set_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags); + + kdebug("schedule"); + schedule_work(&key_gc_work); + + kdebug("sleep"); + wait_on_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE, key_gc_wait_bit, + TASK_UNINTERRUPTIBLE); + + key_gc_dead_keytype = NULL; + kleave(""); +} + +/* + * Garbage collect a list of unreferenced, detached keys + */ +static noinline void key_gc_unused_keys(struct list_head *keys) +{ + while (!list_empty(keys)) { + struct key *key = + list_entry(keys->next, struct key, graveyard_link); + list_del(&key->graveyard_link); + + kdebug("- %u", key->serial); + key_check(key); + + security_key_free(key); + + /* deal with the user's key tracking and quota */ + if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { + spin_lock(&key->user->lock); + key->user->qnkeys--; + key->user->qnbytes -= key->quotalen; + spin_unlock(&key->user->lock); + } + + atomic_dec(&key->user->nkeys); + if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) + atomic_dec(&key->user->nikeys); + + key_user_put(key->user); + + /* now throw away the key memory */ + if (key->type->destroy) + key->type->destroy(key); + + kfree(key->description); + +#ifdef KEY_DEBUGGING + key->magic = KEY_DEBUG_MAGIC_X; +#endif + kmem_cache_free(key_jar, key); + } +} + +/* + * Garbage collector for unused keys. + * + * This is done in process context so that we don't have to disable interrupts + * all over the place. key_put() schedules this rather than trying to do the + * cleanup itself, which means key_put() doesn't have to sleep. + */ +static void key_garbage_collector(struct work_struct *work) +{ + static LIST_HEAD(graveyard); + static u8 gc_state; /* Internal persistent state */ +#define KEY_GC_REAP_AGAIN 0x01 /* - Need another cycle */ +#define KEY_GC_REAPING_LINKS 0x02 /* - We need to reap links */ +#define KEY_GC_SET_TIMER 0x04 /* - We need to restart the timer */ +#define KEY_GC_REAPING_DEAD_1 0x10 /* - We need to mark dead keys */ +#define KEY_GC_REAPING_DEAD_2 0x20 /* - We need to reap dead key links */ +#define KEY_GC_REAPING_DEAD_3 0x40 /* - We need to reap dead keys */ +#define KEY_GC_FOUND_DEAD_KEY 0x80 /* - We found at least one dead key */ + + struct rb_node *cursor; + struct key *key; + time_t new_timer, limit; + + kenter("[%lx,%x]", key_gc_flags, gc_state); + + limit = current_kernel_time().tv_sec; + if (limit > key_gc_delay) + limit -= key_gc_delay; + else + limit = key_gc_delay; + + /* Work out what we're going to be doing in this pass */ + gc_state &= KEY_GC_REAPING_DEAD_1 | KEY_GC_REAPING_DEAD_2; + gc_state <<= 1; + if (test_and_clear_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags)) + gc_state |= KEY_GC_REAPING_LINKS | KEY_GC_SET_TIMER; + + if (test_and_clear_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags)) + gc_state |= KEY_GC_REAPING_DEAD_1; + kdebug("new pass %x", gc_state); + + new_timer = LONG_MAX; + + /* As only this function is permitted to remove things from the key + * serial tree, if cursor is non-NULL then it will always point to a + * valid node in the tree - even if lock got dropped. + */ + spin_lock(&key_serial_lock); + cursor = rb_first(&key_serial_tree); + +continue_scanning: + while (cursor) { + key = rb_entry(cursor, struct key, serial_node); + cursor = rb_next(cursor); + + if (atomic_read(&key->usage) == 0) + goto found_unreferenced_key; + + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_1)) { + if (key->type == key_gc_dead_keytype) { + gc_state |= KEY_GC_FOUND_DEAD_KEY; + set_bit(KEY_FLAG_DEAD, &key->flags); + key->perm = 0; + goto skip_dead_key; + } + } + + if (gc_state & KEY_GC_SET_TIMER) { + if (key->expiry > limit && key->expiry < new_timer) { + kdebug("will expire %x in %ld", + key_serial(key), key->expiry - limit); + new_timer = key->expiry; + } + } + + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2)) + if (key->type == key_gc_dead_keytype) + gc_state |= KEY_GC_FOUND_DEAD_KEY; + + if ((gc_state & KEY_GC_REAPING_LINKS) || + unlikely(gc_state & KEY_GC_REAPING_DEAD_2)) { + if (key->type == &key_type_keyring) + goto found_keyring; + } + + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_3)) + if (key->type == key_gc_dead_keytype) + goto destroy_dead_key; + + skip_dead_key: + if (spin_is_contended(&key_serial_lock) || need_resched()) + goto contended; + } + +contended: + spin_unlock(&key_serial_lock); + +maybe_resched: + if (cursor) { + cond_resched(); + spin_lock(&key_serial_lock); + goto continue_scanning; + } + + /* We've completed the pass. Set the timer if we need to and queue a + * new cycle if necessary. We keep executing cycles until we find one + * where we didn't reap any keys. + */ + kdebug("pass complete"); + + if (gc_state & KEY_GC_SET_TIMER && new_timer != (time_t)LONG_MAX) { + new_timer += key_gc_delay; + key_schedule_gc(new_timer); + } + + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2) || + !list_empty(&graveyard)) { + /* Make sure that all pending keyring payload destructions are + * fulfilled and that people aren't now looking at dead or + * dying keys that they don't have a reference upon or a link + * to. + */ + kdebug("gc sync"); + synchronize_rcu(); + } + + if (!list_empty(&graveyard)) { + kdebug("gc keys"); + key_gc_unused_keys(&graveyard); + } + + if (unlikely(gc_state & (KEY_GC_REAPING_DEAD_1 | + KEY_GC_REAPING_DEAD_2))) { + if (!(gc_state & KEY_GC_FOUND_DEAD_KEY)) { + /* No remaining dead keys: short circuit the remaining + * keytype reap cycles. + */ + kdebug("dead short"); + gc_state &= ~(KEY_GC_REAPING_DEAD_1 | KEY_GC_REAPING_DEAD_2); + gc_state |= KEY_GC_REAPING_DEAD_3; + } else { + gc_state |= KEY_GC_REAP_AGAIN; + } + } + + if (unlikely(gc_state & KEY_GC_REAPING_DEAD_3)) { + kdebug("dead wake"); + smp_mb(); + clear_bit(KEY_GC_REAPING_KEYTYPE, &key_gc_flags); + wake_up_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE); + } + + if (gc_state & KEY_GC_REAP_AGAIN) + schedule_work(&key_gc_work); + kleave(" [end %x]", gc_state); + return; + + /* We found an unreferenced key - once we've removed it from the tree, + * we can safely drop the lock. + */ +found_unreferenced_key: + kdebug("unrefd key %d", key->serial); + rb_erase(&key->serial_node, &key_serial_tree); + spin_unlock(&key_serial_lock); + + list_add_tail(&key->graveyard_link, &graveyard); + gc_state |= KEY_GC_REAP_AGAIN; + goto maybe_resched; + + /* We found a keyring and we need to check the payload for links to + * dead or expired keys. We don't flag another reap immediately as we + * have to wait for the old payload to be destroyed by RCU before we + * can reap the keys to which it refers. + */ +found_keyring: + spin_unlock(&key_serial_lock); + keyring_gc(key, limit); + goto maybe_resched; + + /* We found a dead key that is still referenced. Reset its type and + * destroy its payload with its semaphore held. + */ +destroy_dead_key: + spin_unlock(&key_serial_lock); + kdebug("destroy key %d", key->serial); + down_write(&key->sem); + key->type = &key_type_dead; + if (key_gc_dead_keytype->destroy) + key_gc_dead_keytype->destroy(key); + memset(&key->payload, KEY_DESTROY, sizeof(key->payload)); + up_write(&key->sem); + goto maybe_resched; +} diff --git a/security/keys/internal.h b/security/keys/internal.h index d36d6939335..5f20da01fd8 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -1,4 +1,4 @@ -/* internal.h: authentication token and access key management internal defs +/* Authentication token and access key management internal defs * * Copyright (C) 2003-5, 2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) @@ -12,38 +12,40 @@ #ifndef _INTERNAL_H #define _INTERNAL_H +#include <linux/sched.h> #include <linux/key-type.h> -#include <linux/key-ui.h> +#include <linux/task_work.h> -static inline __attribute__((format(printf, 1, 2))) -void no_printk(const char *fmt, ...) -{ -} +struct iovec; #ifdef __KDEBUG #define kenter(FMT, ...) \ - printk(KERN_DEBUG "==> %s("FMT")\n", __FUNCTION__, ##__VA_ARGS__) + printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) #define kleave(FMT, ...) \ - printk(KERN_DEBUG "<== %s()"FMT"\n", __FUNCTION__, ##__VA_ARGS__) + printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) #define kdebug(FMT, ...) \ - printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__) + printk(KERN_DEBUG " "FMT"\n", ##__VA_ARGS__) #else #define kenter(FMT, ...) \ - no_printk(KERN_DEBUG "==> %s("FMT")\n", __FUNCTION__, ##__VA_ARGS__) + no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) #define kleave(FMT, ...) \ - no_printk(KERN_DEBUG "<== %s()"FMT"\n", __FUNCTION__, ##__VA_ARGS__) + no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) #define kdebug(FMT, ...) \ no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__) #endif +extern struct key_type key_type_dead; extern struct key_type key_type_user; +extern struct key_type key_type_logon; /*****************************************************************************/ /* - * keep track of keys for a user - * - this needs to be separate to user_struct to avoid a refcount-loop - * (user_struct pins some keyrings which pin this struct) - * - this also keeps track of keys under request from userspace for this UID + * Keep track of keys for a user. + * + * This needs to be separate to user_struct to avoid a refcount-loop + * (user_struct pins some keyrings which pin this struct). + * + * We also keep track of keys under request from userspace for this UID here. */ struct key_user { struct rb_node node; @@ -52,86 +54,166 @@ struct key_user { atomic_t usage; /* for accessing qnkeys & qnbytes */ atomic_t nkeys; /* number of keys */ atomic_t nikeys; /* number of instantiated keys */ - uid_t uid; + kuid_t uid; int qnkeys; /* number of keys allocated to this user */ int qnbytes; /* number of bytes allocated to this user */ }; -#define KEYQUOTA_MAX_KEYS 100 -#define KEYQUOTA_MAX_BYTES 10000 -#define KEYQUOTA_LINK_BYTES 4 /* a link in a keyring is worth 4 bytes */ - extern struct rb_root key_user_tree; extern spinlock_t key_user_lock; extern struct key_user root_key_user; -extern struct key_user *key_user_lookup(uid_t uid); +extern struct key_user *key_user_lookup(kuid_t uid); extern void key_user_put(struct key_user *user); +/* + * Key quota limits. + * - root has its own separate limits to everyone else + */ +extern unsigned key_quota_root_maxkeys; +extern unsigned key_quota_root_maxbytes; +extern unsigned key_quota_maxkeys; +extern unsigned key_quota_maxbytes; + +#define KEYQUOTA_LINK_BYTES 4 /* a link in a keyring is worth 4 bytes */ +extern struct kmem_cache *key_jar; extern struct rb_root key_serial_tree; extern spinlock_t key_serial_lock; -extern struct semaphore key_alloc_sem; extern struct mutex key_construction_mutex; extern wait_queue_head_t request_key_conswq; -extern void keyring_publish_name(struct key *keyring); +extern struct key_type *key_type_lookup(const char *type); +extern void key_type_put(struct key_type *ktype); -extern int __key_link(struct key *keyring, struct key *key); +extern int __key_link_begin(struct key *keyring, + const struct keyring_index_key *index_key, + struct assoc_array_edit **_edit); +extern int __key_link_check_live_key(struct key *keyring, struct key *key); +extern void __key_link(struct key *key, struct assoc_array_edit **_edit); +extern void __key_link_end(struct key *keyring, + const struct keyring_index_key *index_key, + struct assoc_array_edit *edit); -extern key_ref_t __keyring_search_one(key_ref_t keyring_ref, - const struct key_type *type, - const char *description, - key_perm_t perm); +extern key_ref_t find_key_to_update(key_ref_t keyring_ref, + const struct keyring_index_key *index_key); extern struct key *keyring_search_instkey(struct key *keyring, key_serial_t target_id); +extern int iterate_over_keyring(const struct key *keyring, + int (*func)(const struct key *key, void *data), + void *data); + typedef int (*key_match_func_t)(const struct key *, const void *); +struct keyring_search_context { + struct keyring_index_key index_key; + const struct cred *cred; + key_match_func_t match; + const void *match_data; + unsigned flags; +#define KEYRING_SEARCH_LOOKUP_TYPE 0x0001 /* [as type->def_lookup_type] */ +#define KEYRING_SEARCH_NO_STATE_CHECK 0x0002 /* Skip state checks */ +#define KEYRING_SEARCH_DO_STATE_CHECK 0x0004 /* Override NO_STATE_CHECK */ +#define KEYRING_SEARCH_NO_UPDATE_TIME 0x0008 /* Don't update times */ +#define KEYRING_SEARCH_NO_CHECK_PERM 0x0010 /* Don't check permissions */ +#define KEYRING_SEARCH_DETECT_TOO_DEEP 0x0020 /* Give an error on excessive depth */ + + int (*iterator)(const void *object, void *iterator_data); + + /* Internal stuff */ + int skipped_ret; + bool possessed; + key_ref_t result; + struct timespec now; +}; + extern key_ref_t keyring_search_aux(key_ref_t keyring_ref, - struct task_struct *tsk, - struct key_type *type, - const void *description, - key_match_func_t match); + struct keyring_search_context *ctx); -extern key_ref_t search_process_keyrings(struct key_type *type, - const void *description, - key_match_func_t match, - struct task_struct *tsk); +extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx); +extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx); -extern struct key *find_keyring_by_name(const char *name, key_serial_t bound); +extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check); -extern int install_thread_keyring(struct task_struct *tsk); -extern int install_process_keyring(struct task_struct *tsk); +extern int install_user_keyrings(void); +extern int install_thread_keyring_to_cred(struct cred *); +extern int install_process_keyring_to_cred(struct cred *); +extern int install_session_keyring_to_cred(struct cred *, struct key *); extern struct key *request_key_and_link(struct key_type *type, const char *description, - const char *callout_info, + const void *callout_info, + size_t callout_len, void *aux, struct key *dest_keyring, unsigned long flags); +extern int lookup_user_key_possessed(const struct key *key, const void *target); +extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags, + key_perm_t perm); +#define KEY_LOOKUP_CREATE 0x01 +#define KEY_LOOKUP_PARTIAL 0x02 +#define KEY_LOOKUP_FOR_UNLINK 0x04 + +extern long join_session_keyring(const char *name); +extern void key_change_session_keyring(struct callback_head *twork); + +extern struct work_struct key_gc_work; +extern unsigned key_gc_delay; +extern void keyring_gc(struct key *keyring, time_t limit); +extern void key_schedule_gc(time_t gc_at); +extern void key_schedule_gc_links(void); +extern void key_gc_keytype(struct key_type *ktype); + +extern int key_task_permission(const key_ref_t key_ref, + const struct cred *cred, + key_perm_t perm); + +/* + * Check to see whether permission is granted to use a key in the desired way. + */ +static inline int key_permission(const key_ref_t key_ref, unsigned perm) +{ + return key_task_permission(key_ref, current_cred(), perm); +} + /* - * request_key authorisation + * Authorisation record for request_key(). */ struct request_key_auth { struct key *target_key; - struct task_struct *context; - char *callout_info; + struct key *dest_keyring; + const struct cred *cred; + void *callout_info; + size_t callout_len; pid_t pid; }; extern struct key_type key_type_request_key_auth; extern struct key *request_key_auth_new(struct key *target, - const char *callout_info); + const void *callout_info, + size_t callout_len, + struct key *dest_keyring); extern struct key *key_get_instantiation_authkey(key_serial_t target_id); /* - * keyctl functions + * Determine whether a key is dead. + */ +static inline bool key_is_dead(const struct key *key, time_t limit) +{ + return + key->flags & ((1 << KEY_FLAG_DEAD) | + (1 << KEY_FLAG_INVALIDATED)) || + (key->expiry > 0 && key->expiry <= limit); +} + +/* + * keyctl() functions */ extern long keyctl_get_keyring_ID(key_serial_t, int); extern long keyctl_join_session_keyring(const char __user *); @@ -152,10 +234,30 @@ extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t); extern long keyctl_set_reqkey_keyring(int); extern long keyctl_set_timeout(key_serial_t, unsigned); extern long keyctl_assume_authority(key_serial_t); - +extern long keyctl_get_security(key_serial_t keyid, char __user *buffer, + size_t buflen); +extern long keyctl_session_to_parent(void); +extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t); +extern long keyctl_instantiate_key_iov(key_serial_t, + const struct iovec __user *, + unsigned, key_serial_t); +extern long keyctl_invalidate_key(key_serial_t); + +extern long keyctl_instantiate_key_common(key_serial_t, + const struct iovec *, + unsigned, size_t, key_serial_t); +#ifdef CONFIG_PERSISTENT_KEYRINGS +extern long keyctl_get_persistent(uid_t, key_serial_t); +extern unsigned persistent_keyring_expiry; +#else +static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring) +{ + return -EOPNOTSUPP; +} +#endif /* - * debugging key validation + * Debugging key validation */ #ifdef KEY_DEBUGGING extern void __key_check(const struct key *); diff --git a/security/keys/key.c b/security/keys/key.c index 654d23baf35..2048a110e7f 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -1,6 +1,6 @@ /* Basic authentication token and access key management * - * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -20,27 +20,24 @@ #include <linux/err.h> #include "internal.h" -static struct kmem_cache *key_jar; +struct kmem_cache *key_jar; struct rb_root key_serial_tree; /* tree of keys indexed by serial */ DEFINE_SPINLOCK(key_serial_lock); struct rb_root key_user_tree; /* tree of quota records indexed by UID */ DEFINE_SPINLOCK(key_user_lock); +unsigned int key_quota_root_maxkeys = 200; /* root's key count quota */ +unsigned int key_quota_root_maxbytes = 20000; /* root's key space quota */ +unsigned int key_quota_maxkeys = 200; /* general key count quota */ +unsigned int key_quota_maxbytes = 20000; /* general key space quota */ + static LIST_HEAD(key_types_list); static DECLARE_RWSEM(key_types_sem); -static void key_cleanup(struct work_struct *work); -static DECLARE_WORK(key_cleanup_task, key_cleanup); - -/* we serialise key instantiation and link */ +/* We serialise key instantiation and link */ DEFINE_MUTEX(key_construction_mutex); -/* any key who's type gets unegistered will be re-typed to this */ -static struct key_type key_type_dead = { - .name = "dead", -}; - #ifdef KEY_DEBUGGING void __key_check(const struct key *key) { @@ -50,18 +47,17 @@ void __key_check(const struct key *key) } #endif -/*****************************************************************************/ /* - * get the key quota record for a user, allocating a new record if one doesn't - * already exist + * Get the key quota record for a user, allocating a new record if one doesn't + * already exist. */ -struct key_user *key_user_lookup(uid_t uid) +struct key_user *key_user_lookup(kuid_t uid) { struct key_user *candidate = NULL, *user; struct rb_node *parent = NULL; struct rb_node **p; - try_again: +try_again: p = &key_user_tree.rb_node; spin_lock(&key_user_lock); @@ -70,9 +66,9 @@ struct key_user *key_user_lookup(uid_t uid) parent = *p; user = rb_entry(parent, struct key_user, node); - if (uid < user->uid) + if (uid_lt(uid, user->uid)) p = &(*p)->rb_left; - else if (uid > user->uid) + else if (uid_gt(uid, user->uid)) p = &(*p)->rb_right; else goto found; @@ -113,18 +109,16 @@ struct key_user *key_user_lookup(uid_t uid) goto out; /* okay - we found a user record for this UID */ - found: +found: atomic_inc(&user->usage); spin_unlock(&key_user_lock); kfree(candidate); - out: +out: return user; +} -} /* end key_user_lookup() */ - -/*****************************************************************************/ /* - * dispose of a user structure + * Dispose of a user structure */ void key_user_put(struct key_user *user) { @@ -134,44 +128,11 @@ void key_user_put(struct key_user *user) kfree(user); } +} -} /* end key_user_put() */ - -/*****************************************************************************/ -/* - * insert a key with a fixed serial number - */ -static void __init __key_insert_serial(struct key *key) -{ - struct rb_node *parent, **p; - struct key *xkey; - - parent = NULL; - p = &key_serial_tree.rb_node; - - while (*p) { - parent = *p; - xkey = rb_entry(parent, struct key, serial_node); - - if (key->serial < xkey->serial) - p = &(*p)->rb_left; - else if (key->serial > xkey->serial) - p = &(*p)->rb_right; - else - BUG(); - } - - /* we've found a suitable hole - arrange for this key to occupy it */ - rb_link_node(&key->serial_node, parent, p); - rb_insert_color(&key->serial_node, &key_serial_tree); - -} /* end __key_insert_serial() */ - -/*****************************************************************************/ /* - * assign a key the next unique serial number - * - these are assigned randomly to avoid security issues through covert - * channel problems + * Allocate a serial number for a key. These are assigned randomly to avoid + * security issues through covert channel problems. */ static inline void key_alloc_serial(struct key *key) { @@ -229,21 +190,39 @@ serial_exists: if (key->serial < xkey->serial) goto attempt_insertion; } +} -} /* end key_alloc_serial() */ - -/*****************************************************************************/ -/* - * allocate a key of the specified type - * - update the user's quota to reflect the existence of the key - * - called from a key-type operation with key_types_sem read-locked by - * key_create_or_update() - * - this prevents unregistration of the key type - * - upon return the key is as yet uninstantiated; the caller needs to either - * instantiate the key or discard it before returning +/** + * key_alloc - Allocate a key of the specified type. + * @type: The type of key to allocate. + * @desc: The key description to allow the key to be searched out. + * @uid: The owner of the new key. + * @gid: The group ID for the new key's group permissions. + * @cred: The credentials specifying UID namespace. + * @perm: The permissions mask of the new key. + * @flags: Flags specifying quota properties. + * + * Allocate a key of the specified type with the attributes given. The key is + * returned in an uninstantiated state and the caller needs to instantiate the + * key before returning. + * + * The user's key count quota is updated to reflect the creation of the key and + * the user's key data quota has the default for the key type reserved. The + * instantiation function should amend this as necessary. If insufficient + * quota is available, -EDQUOT will be returned. + * + * The LSM security modules can prevent a key being created, in which case + * -EACCES will be returned. + * + * Returns a pointer to the new key if successful and an error code otherwise. + * + * Note that the caller needs to ensure the key type isn't uninstantiated. + * Internally this can be done by locking key_types_sem. Externally, this can + * be done by either never unregistering the key type, or making sure + * key_alloc() calls don't race with module unloading. */ struct key *key_alloc(struct key_type *type, const char *desc, - uid_t uid, gid_t gid, struct task_struct *ctx, + kuid_t uid, kgid_t gid, const struct cred *cred, key_perm_t perm, unsigned long flags) { struct key_user *user = NULL; @@ -255,8 +234,16 @@ struct key *key_alloc(struct key_type *type, const char *desc, if (!desc || !*desc) goto error; - desclen = strlen(desc) + 1; - quotalen = desclen + type->def_datalen; + if (type->vet_description) { + ret = type->vet_description(desc); + if (ret < 0) { + key = ERR_PTR(ret); + goto error; + } + } + + desclen = strlen(desc); + quotalen = desclen + 1 + type->def_datalen; /* get hold of the key tracking for this user */ user = key_user_lookup(uid); @@ -266,11 +253,16 @@ struct key *key_alloc(struct key_type *type, const char *desc, /* check that the user's quota permits allocation of another key and * its description */ if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { + unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxkeys : key_quota_maxkeys; + unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxbytes : key_quota_maxbytes; + spin_lock(&user->lock); if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { - if (user->qnkeys + 1 >= KEYQUOTA_MAX_KEYS || - user->qnbytes + quotalen >= KEYQUOTA_MAX_BYTES - ) + if (user->qnkeys + 1 >= maxkeys || + user->qnbytes + quotalen >= maxbytes || + user->qnbytes + quotalen < user->qnbytes) goto no_quota; } @@ -280,41 +272,39 @@ struct key *key_alloc(struct key_type *type, const char *desc, } /* allocate and initialise the key and its description */ - key = kmem_cache_alloc(key_jar, GFP_KERNEL); + key = kmem_cache_zalloc(key_jar, GFP_KERNEL); if (!key) goto no_memory_2; if (desc) { - key->description = kmemdup(desc, desclen, GFP_KERNEL); + key->index_key.desc_len = desclen; + key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL); if (!key->description) goto no_memory_3; } atomic_set(&key->usage, 1); init_rwsem(&key->sem); - key->type = type; + lockdep_set_class(&key->sem, &type->lock_class); + key->index_key.type = type; key->user = user; key->quotalen = quotalen; key->datalen = type->def_datalen; key->uid = uid; key->gid = gid; key->perm = perm; - key->flags = 0; - key->expiry = 0; - key->payload.data = NULL; - key->security = NULL; if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) key->flags |= 1 << KEY_FLAG_IN_QUOTA; - - memset(&key->type_data, 0, sizeof(key->type_data)); + if (flags & KEY_ALLOC_TRUSTED) + key->flags |= 1 << KEY_FLAG_TRUSTED; #ifdef KEY_DEBUGGING key->magic = KEY_DEBUG_MAGIC; #endif /* let the security module know about the key */ - ret = security_key_alloc(key, ctx, flags); + ret = security_key_alloc(key, cred, flags); if (ret < 0) goto security_error; @@ -357,29 +347,37 @@ no_quota: key_user_put(user); key = ERR_PTR(-EDQUOT); goto error; - -} /* end key_alloc() */ - +} EXPORT_SYMBOL(key_alloc); -/*****************************************************************************/ -/* - * reserve an amount of quota for the key's payload +/** + * key_payload_reserve - Adjust data quota reservation for the key's payload + * @key: The key to make the reservation for. + * @datalen: The amount of data payload the caller now wants. + * + * Adjust the amount of the owning user's key data quota that a key reserves. + * If the amount is increased, then -EDQUOT may be returned if there isn't + * enough free quota available. + * + * If successful, 0 is returned. */ int key_payload_reserve(struct key *key, size_t datalen) { - int delta = (int) datalen - key->datalen; + int delta = (int)datalen - key->datalen; int ret = 0; key_check(key); /* contemplate the quota adjustment */ if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { + unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxbytes : key_quota_maxbytes; + spin_lock(&key->user->lock); if (delta > 0 && - key->user->qnbytes + delta > KEYQUOTA_MAX_BYTES - ) { + (key->user->qnbytes + delta >= maxbytes || + key->user->qnbytes + delta < key->user->qnbytes)) { ret = -EDQUOT; } else { @@ -394,21 +392,20 @@ int key_payload_reserve(struct key *key, size_t datalen) key->datalen = datalen; return ret; - -} /* end key_payload_reserve() */ - +} EXPORT_SYMBOL(key_payload_reserve); -/*****************************************************************************/ /* - * instantiate a key and link it into the target keyring atomically - * - called with the target keyring's semaphore writelocked + * Instantiate a key and link it into the target keyring atomically. Must be + * called with the target keyring's semaphore writelocked. The target key's + * semaphore need not be locked as instantiation is serialised by + * key_construction_mutex. */ static int __key_instantiate_and_link(struct key *key, - const void *data, - size_t datalen, + struct key_preparsed_payload *prep, struct key *keyring, - struct key *instkey) + struct key *authkey, + struct assoc_array_edit **_edit) { int ret, awaken; @@ -423,7 +420,7 @@ static int __key_instantiate_and_link(struct key *key, /* can't instantiate twice */ if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { /* instantiate the key */ - ret = key->type->instantiate(key, data, datalen); + ret = key->type->instantiate(key, prep); if (ret == 0) { /* mark the key as being instantiated */ @@ -435,11 +432,11 @@ static int __key_instantiate_and_link(struct key *key, /* and link it into the destination keyring */ if (keyring) - ret = __key_link(keyring, key); + __key_link(key, _edit); /* disable the authorisation key */ - if (instkey) - key_revoke(instkey); + if (authkey) + key_revoke(authkey); } } @@ -450,46 +447,94 @@ static int __key_instantiate_and_link(struct key *key, wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); return ret; +} -} /* end __key_instantiate_and_link() */ - -/*****************************************************************************/ -/* - * instantiate a key and link it into the target keyring atomically +/** + * key_instantiate_and_link - Instantiate a key and link it into the keyring. + * @key: The key to instantiate. + * @data: The data to use to instantiate the keyring. + * @datalen: The length of @data. + * @keyring: Keyring to create a link in on success (or NULL). + * @authkey: The authorisation token permitting instantiation. + * + * Instantiate a key that's in the uninstantiated state using the provided data + * and, if successful, link it in to the destination keyring if one is + * supplied. + * + * If successful, 0 is returned, the authorisation token is revoked and anyone + * waiting for the key is woken up. If the key was already instantiated, + * -EBUSY will be returned. */ int key_instantiate_and_link(struct key *key, const void *data, size_t datalen, struct key *keyring, - struct key *instkey) + struct key *authkey) { + struct key_preparsed_payload prep; + struct assoc_array_edit *edit; int ret; - if (keyring) - down_write(&keyring->sem); + memset(&prep, 0, sizeof(prep)); + prep.data = data; + prep.datalen = datalen; + prep.quotalen = key->type->def_datalen; + if (key->type->preparse) { + ret = key->type->preparse(&prep); + if (ret < 0) + goto error; + } + + if (keyring) { + ret = __key_link_begin(keyring, &key->index_key, &edit); + if (ret < 0) + goto error_free_preparse; + } - ret = __key_instantiate_and_link(key, data, datalen, keyring, instkey); + ret = __key_instantiate_and_link(key, &prep, keyring, authkey, &edit); if (keyring) - up_write(&keyring->sem); + __key_link_end(keyring, &key->index_key, edit); +error_free_preparse: + if (key->type->preparse) + key->type->free_preparse(&prep); +error: return ret; - -} /* end key_instantiate_and_link() */ +} EXPORT_SYMBOL(key_instantiate_and_link); -/*****************************************************************************/ -/* - * negatively instantiate a key and link it into the target keyring atomically +/** + * key_reject_and_link - Negatively instantiate a key and link it into the keyring. + * @key: The key to instantiate. + * @timeout: The timeout on the negative key. + * @error: The error to return when the key is hit. + * @keyring: Keyring to create a link in on success (or NULL). + * @authkey: The authorisation token permitting instantiation. + * + * Negatively instantiate a key that's in the uninstantiated state and, if + * successful, set its timeout and stored error and link it in to the + * destination keyring if one is supplied. The key and any links to the key + * will be automatically garbage collected after the timeout expires. + * + * Negative keys are used to rate limit repeated request_key() calls by causing + * them to return the stored error code (typically ENOKEY) until the negative + * key expires. + * + * If successful, 0 is returned, the authorisation token is revoked and anyone + * waiting for the key is woken up. If the key was already instantiated, + * -EBUSY will be returned. */ -int key_negate_and_link(struct key *key, +int key_reject_and_link(struct key *key, unsigned timeout, + unsigned error, struct key *keyring, - struct key *instkey) + struct key *authkey) { + struct assoc_array_edit *edit; struct timespec now; - int ret, awaken; + int ret, awaken, link_ret = 0; key_check(key); key_check(keyring); @@ -498,7 +543,7 @@ int key_negate_and_link(struct key *key, ret = -EBUSY; if (keyring) - down_write(&keyring->sem); + link_ret = __key_link_begin(keyring, &key->index_key, &edit); mutex_lock(&key_construction_mutex); @@ -506,10 +551,13 @@ int key_negate_and_link(struct key *key, if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) { /* mark the key as being negatively instantiated */ atomic_inc(&key->user->nikeys); + key->type_data.reject_error = -error; + smp_wmb(); set_bit(KEY_FLAG_NEGATIVE, &key->flags); set_bit(KEY_FLAG_INSTANTIATED, &key->flags); now = current_kernel_time(); key->expiry = now.tv_sec + timeout; + key_schedule_gc(key->expiry + key_gc_delay); if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) awaken = 1; @@ -517,98 +565,34 @@ int key_negate_and_link(struct key *key, ret = 0; /* and link it into the destination keyring */ - if (keyring) - ret = __key_link(keyring, key); + if (keyring && link_ret == 0) + __key_link(key, &edit); /* disable the authorisation key */ - if (instkey) - key_revoke(instkey); + if (authkey) + key_revoke(authkey); } mutex_unlock(&key_construction_mutex); if (keyring) - up_write(&keyring->sem); + __key_link_end(keyring, &key->index_key, edit); /* wake up anyone waiting for a key to be constructed */ if (awaken) wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); - return ret; - -} /* end key_negate_and_link() */ - -EXPORT_SYMBOL(key_negate_and_link); - -/*****************************************************************************/ -/* - * do cleaning up in process context so that we don't have to disable - * interrupts all over the place - */ -static void key_cleanup(struct work_struct *work) -{ - struct rb_node *_n; - struct key *key; - - go_again: - /* look for a dead key in the tree */ - spin_lock(&key_serial_lock); - - for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { - key = rb_entry(_n, struct key, serial_node); - - if (atomic_read(&key->usage) == 0) - goto found_dead_key; - } - - spin_unlock(&key_serial_lock); - return; - - found_dead_key: - /* we found a dead key - once we've removed it from the tree, we can - * drop the lock */ - rb_erase(&key->serial_node, &key_serial_tree); - spin_unlock(&key_serial_lock); - - key_check(key); - - security_key_free(key); - - /* deal with the user's key tracking and quota */ - if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { - spin_lock(&key->user->lock); - key->user->qnkeys--; - key->user->qnbytes -= key->quotalen; - spin_unlock(&key->user->lock); - } - - atomic_dec(&key->user->nkeys); - if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) - atomic_dec(&key->user->nikeys); - - key_user_put(key->user); - - /* now throw away the key memory */ - if (key->type->destroy) - key->type->destroy(key); - - kfree(key->description); - -#ifdef KEY_DEBUGGING - key->magic = KEY_DEBUG_MAGIC_X; -#endif - kmem_cache_free(key_jar, key); - - /* there may, of course, be more than one key to destroy */ - goto go_again; - -} /* end key_cleanup() */ + return ret == 0 ? link_ret : ret; +} +EXPORT_SYMBOL(key_reject_and_link); -/*****************************************************************************/ -/* - * dispose of a reference to a key - * - when all the references are gone, we schedule the cleanup task to come and - * pull it out of the tree in definite process context +/** + * key_put - Discard a reference to a key. + * @key: The key to discard a reference from. + * + * Discard a reference to a key, and when all the references are gone, we + * schedule the cleanup task to come and pull it out of the tree in process + * context at some later time. */ void key_put(struct key *key) { @@ -616,16 +600,13 @@ void key_put(struct key *key) key_check(key); if (atomic_dec_and_test(&key->usage)) - schedule_work(&key_cleanup_task); + schedule_work(&key_gc_work); } - -} /* end key_put() */ - +} EXPORT_SYMBOL(key_put); -/*****************************************************************************/ /* - * find a key by its serial number + * Find a key by its serial number. */ struct key *key_lookup(key_serial_t id) { @@ -647,32 +628,30 @@ struct key *key_lookup(key_serial_t id) goto found; } - not_found: +not_found: key = ERR_PTR(-ENOKEY); goto error; - found: - /* pretend it doesn't exist if it's dead */ - if (atomic_read(&key->usage) == 0 || - test_bit(KEY_FLAG_DEAD, &key->flags) || - key->type == &key_type_dead) +found: + /* pretend it doesn't exist if it is awaiting deletion */ + if (atomic_read(&key->usage) == 0) goto not_found; /* this races with key_put(), but that doesn't matter since key_put() * doesn't actually change the key */ - atomic_inc(&key->usage); + __key_get(key); - error: +error: spin_unlock(&key_serial_lock); return key; +} -} /* end key_lookup() */ - -/*****************************************************************************/ /* - * find and lock the specified key type against removal - * - we return with the sem readlocked + * Find and lock the specified key type against removal. + * + * We return with the sem read-locked if successful. If the type wasn't + * available -ENOKEY is returned instead. */ struct key_type *key_type_lookup(const char *type) { @@ -690,35 +669,52 @@ struct key_type *key_type_lookup(const char *type) up_read(&key_types_sem); ktype = ERR_PTR(-ENOKEY); - found_kernel_type: +found_kernel_type: return ktype; +} -} /* end key_type_lookup() */ +void key_set_timeout(struct key *key, unsigned timeout) +{ + struct timespec now; + time_t expiry = 0; + + /* make the changes with the locks held to prevent races */ + down_write(&key->sem); + + if (timeout > 0) { + now = current_kernel_time(); + expiry = now.tv_sec + timeout; + } + + key->expiry = expiry; + key_schedule_gc(key->expiry + key_gc_delay); + + up_write(&key->sem); +} +EXPORT_SYMBOL_GPL(key_set_timeout); -/*****************************************************************************/ /* - * unlock a key type + * Unlock a key type locked by key_type_lookup(). */ void key_type_put(struct key_type *ktype) { up_read(&key_types_sem); +} -} /* end key_type_put() */ - -/*****************************************************************************/ /* - * attempt to update an existing key - * - the key has an incremented refcount - * - we need to put the key if we get an error + * Attempt to update an existing key. + * + * The key is given to us with an incremented refcount that we need to discard + * if we get an error. */ static inline key_ref_t __key_update(key_ref_t key_ref, - const void *payload, size_t plen) + struct key_preparsed_payload *prep) { struct key *key = key_ref_to_ptr(key_ref); int ret; /* need write permission on the key to update it */ - ret = key_permission(key_ref, KEY_WRITE); + ret = key_permission(key_ref, KEY_NEED_WRITE); if (ret < 0) goto error; @@ -728,7 +724,7 @@ static inline key_ref_t __key_update(key_ref_t key_ref, down_write(&key->sem); - ret = key->type->update(key, payload, plen); + ret = key->type->update(key, prep); if (ret == 0) /* updating a negative key instantiates it */ clear_bit(KEY_FLAG_NEGATIVE, &key->flags); @@ -744,38 +740,63 @@ error: key_put(key); key_ref = ERR_PTR(ret); goto out; +} -} /* end __key_update() */ - -/*****************************************************************************/ -/* - * search the specified keyring for a key of the same description; if one is - * found, update it, otherwise add a new one +/** + * key_create_or_update - Update or create and instantiate a key. + * @keyring_ref: A pointer to the destination keyring with possession flag. + * @type: The type of key. + * @description: The searchable description for the key. + * @payload: The data to use to instantiate or update the key. + * @plen: The length of @payload. + * @perm: The permissions mask for a new key. + * @flags: The quota flags for a new key. + * + * Search the destination keyring for a key of the same description and if one + * is found, update it, otherwise create and instantiate a new one and create a + * link to it from that keyring. + * + * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be + * concocted. + * + * Returns a pointer to the new key if successful, -ENODEV if the key type + * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the + * caller isn't permitted to modify the keyring or the LSM did not permit + * creation of the key. + * + * On success, the possession flag from the keyring ref will be tacked on to + * the key ref before it is returned. */ key_ref_t key_create_or_update(key_ref_t keyring_ref, const char *type, const char *description, const void *payload, size_t plen, + key_perm_t perm, unsigned long flags) { - struct key_type *ktype; + struct keyring_index_key index_key = { + .description = description, + }; + struct key_preparsed_payload prep; + struct assoc_array_edit *edit; + const struct cred *cred = current_cred(); struct key *keyring, *key = NULL; - key_perm_t perm; key_ref_t key_ref; int ret; /* look up the key type to see if it's one of the registered kernel * types */ - ktype = key_type_lookup(type); - if (IS_ERR(ktype)) { + index_key.type = key_type_lookup(type); + if (IS_ERR(index_key.type)) { key_ref = ERR_PTR(-ENODEV); goto error; } key_ref = ERR_PTR(-EINVAL); - if (!ktype->match || !ktype->instantiate) - goto error_2; + if (!index_key.type->match || !index_key.type->instantiate || + (!index_key.description && !index_key.type->preparse)) + goto error_put_type; keyring = key_ref_to_ptr(keyring_ref); @@ -783,120 +804,179 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, key_ref = ERR_PTR(-ENOTDIR); if (keyring->type != &key_type_keyring) - goto error_2; + goto error_put_type; + + memset(&prep, 0, sizeof(prep)); + prep.data = payload; + prep.datalen = plen; + prep.quotalen = index_key.type->def_datalen; + prep.trusted = flags & KEY_ALLOC_TRUSTED; + if (index_key.type->preparse) { + ret = index_key.type->preparse(&prep); + if (ret < 0) { + key_ref = ERR_PTR(ret); + goto error_put_type; + } + if (!index_key.description) + index_key.description = prep.description; + key_ref = ERR_PTR(-EINVAL); + if (!index_key.description) + goto error_free_prep; + } + index_key.desc_len = strlen(index_key.description); - down_write(&keyring->sem); + key_ref = ERR_PTR(-EPERM); + if (!prep.trusted && test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags)) + goto error_free_prep; + flags |= prep.trusted ? KEY_ALLOC_TRUSTED : 0; + + ret = __key_link_begin(keyring, &index_key, &edit); + if (ret < 0) { + key_ref = ERR_PTR(ret); + goto error_free_prep; + } /* if we're going to allocate a new key, we're going to have * to modify the keyring */ - ret = key_permission(keyring_ref, KEY_WRITE); + ret = key_permission(keyring_ref, KEY_NEED_WRITE); if (ret < 0) { key_ref = ERR_PTR(ret); - goto error_3; + goto error_link_end; } /* if it's possible to update this type of key, search for an existing * key of the same type and description in the destination keyring and * update that instead if possible */ - if (ktype->update) { - key_ref = __keyring_search_one(keyring_ref, ktype, description, - 0); - if (!IS_ERR(key_ref)) + if (index_key.type->update) { + key_ref = find_key_to_update(keyring_ref, &index_key); + if (key_ref) goto found_matching_key; } - /* decide on the permissions we want */ - perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; - perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK | KEY_USR_SETATTR; + /* if the client doesn't provide, decide on the permissions we want */ + if (perm == KEY_PERM_UNDEF) { + perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; + perm |= KEY_USR_VIEW; - if (ktype->read) - perm |= KEY_POS_READ | KEY_USR_READ; + if (index_key.type->read) + perm |= KEY_POS_READ; - if (ktype == &key_type_keyring || ktype->update) - perm |= KEY_USR_WRITE; + if (index_key.type == &key_type_keyring || + index_key.type->update) + perm |= KEY_POS_WRITE; + } /* allocate a new key */ - key = key_alloc(ktype, description, current->fsuid, current->fsgid, - current, perm, flags); + key = key_alloc(index_key.type, index_key.description, + cred->fsuid, cred->fsgid, cred, perm, flags); if (IS_ERR(key)) { key_ref = ERR_CAST(key); - goto error_3; + goto error_link_end; } /* instantiate it and link it into the target keyring */ - ret = __key_instantiate_and_link(key, payload, plen, keyring, NULL); + ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &edit); if (ret < 0) { key_put(key); key_ref = ERR_PTR(ret); - goto error_3; + goto error_link_end; } key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); - error_3: - up_write(&keyring->sem); - error_2: - key_type_put(ktype); - error: +error_link_end: + __key_link_end(keyring, &index_key, edit); +error_free_prep: + if (index_key.type->preparse) + index_key.type->free_preparse(&prep); +error_put_type: + key_type_put(index_key.type); +error: return key_ref; found_matching_key: /* we found a matching key, so we're going to try to update it * - we can drop the locks first as we have the key pinned */ - up_write(&keyring->sem); - key_type_put(ktype); - - key_ref = __key_update(key_ref, payload, plen); - goto error; - -} /* end key_create_or_update() */ + __key_link_end(keyring, &index_key, edit); + key_ref = __key_update(key_ref, &prep); + goto error_free_prep; +} EXPORT_SYMBOL(key_create_or_update); -/*****************************************************************************/ -/* - * update a key +/** + * key_update - Update a key's contents. + * @key_ref: The pointer (plus possession flag) to the key. + * @payload: The data to be used to update the key. + * @plen: The length of @payload. + * + * Attempt to update the contents of a key with the given payload data. The + * caller must be granted Write permission on the key. Negative keys can be + * instantiated by this method. + * + * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key + * type does not support updating. The key type may return other errors. */ int key_update(key_ref_t key_ref, const void *payload, size_t plen) { + struct key_preparsed_payload prep; struct key *key = key_ref_to_ptr(key_ref); int ret; key_check(key); /* the key must be writable */ - ret = key_permission(key_ref, KEY_WRITE); + ret = key_permission(key_ref, KEY_NEED_WRITE); if (ret < 0) goto error; /* attempt to update it if supported */ ret = -EOPNOTSUPP; - if (key->type->update) { - down_write(&key->sem); - - ret = key->type->update(key, payload, plen); - if (ret == 0) - /* updating a negative key instantiates it */ - clear_bit(KEY_FLAG_NEGATIVE, &key->flags); + if (!key->type->update) + goto error; - up_write(&key->sem); + memset(&prep, 0, sizeof(prep)); + prep.data = payload; + prep.datalen = plen; + prep.quotalen = key->type->def_datalen; + if (key->type->preparse) { + ret = key->type->preparse(&prep); + if (ret < 0) + goto error; } - error: - return ret; + down_write(&key->sem); + + ret = key->type->update(key, &prep); + if (ret == 0) + /* updating a negative key instantiates it */ + clear_bit(KEY_FLAG_NEGATIVE, &key->flags); -} /* end key_update() */ + up_write(&key->sem); + if (key->type->preparse) + key->type->free_preparse(&prep); +error: + return ret; +} EXPORT_SYMBOL(key_update); -/*****************************************************************************/ -/* - * revoke a key +/** + * key_revoke - Revoke a key. + * @key: The key to be revoked. + * + * Mark a key as being revoked and ask the type to free up its resources. The + * revocation timeout is set and the key and all its links will be + * automatically garbage collected after key_gc_delay amount of time if they + * are not manually dealt with first. */ void key_revoke(struct key *key) { + struct timespec now; + time_t time; + key_check(key); /* make sure no one's trying to change or use the key when we mark it @@ -909,21 +989,55 @@ void key_revoke(struct key *key) key->type->revoke) key->type->revoke(key); + /* set the death time to no more than the expiry time */ + now = current_kernel_time(); + time = now.tv_sec; + if (key->revoked_at == 0 || key->revoked_at > time) { + key->revoked_at = time; + key_schedule_gc(key->revoked_at + key_gc_delay); + } + up_write(&key->sem); +} +EXPORT_SYMBOL(key_revoke); -} /* end key_revoke() */ +/** + * key_invalidate - Invalidate a key. + * @key: The key to be invalidated. + * + * Mark a key as being invalidated and have it cleaned up immediately. The key + * is ignored by all searches and other operations from this point. + */ +void key_invalidate(struct key *key) +{ + kenter("%d", key_serial(key)); -EXPORT_SYMBOL(key_revoke); + key_check(key); -/*****************************************************************************/ -/* - * register a type of key + if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) { + down_write_nested(&key->sem, 1); + if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags)) + key_schedule_gc_links(); + up_write(&key->sem); + } +} +EXPORT_SYMBOL(key_invalidate); + +/** + * register_key_type - Register a type of key. + * @ktype: The new key type. + * + * Register a new key type. + * + * Returns 0 on success or -EEXIST if a type of this name already exists. */ int register_key_type(struct key_type *ktype) { struct key_type *p; int ret; + memset(&ktype->lock_class, 0, sizeof(ktype->lock_class)); + ret = -EEXIST; down_write(&key_types_sem); @@ -935,69 +1049,37 @@ int register_key_type(struct key_type *ktype) /* store the type */ list_add(&ktype->link, &key_types_list); + + pr_notice("Key type %s registered\n", ktype->name); ret = 0; - out: +out: up_write(&key_types_sem); return ret; - -} /* end register_key_type() */ - +} EXPORT_SYMBOL(register_key_type); -/*****************************************************************************/ -/* - * unregister a type of key +/** + * unregister_key_type - Unregister a type of key. + * @ktype: The key type. + * + * Unregister a key type and mark all the extant keys of this type as dead. + * Those keys of this type are then destroyed to get rid of their payloads and + * they and their links will be garbage collected as soon as possible. */ void unregister_key_type(struct key_type *ktype) { - struct rb_node *_n; - struct key *key; - down_write(&key_types_sem); - - /* withdraw the key type */ list_del_init(&ktype->link); - - /* mark all the keys of this type dead */ - spin_lock(&key_serial_lock); - - for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { - key = rb_entry(_n, struct key, serial_node); - - if (key->type == ktype) - key->type = &key_type_dead; - } - - spin_unlock(&key_serial_lock); - - /* make sure everyone revalidates their keys */ - synchronize_rcu(); - - /* we should now be able to destroy the payloads of all the keys of - * this type with impunity */ - spin_lock(&key_serial_lock); - - for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) { - key = rb_entry(_n, struct key, serial_node); - - if (key->type == ktype) { - if (ktype->destroy) - ktype->destroy(key); - memset(&key->payload, KEY_DESTROY, sizeof(key->payload)); - } - } - - spin_unlock(&key_serial_lock); - up_write(&key_types_sem); - -} /* end unregister_key_type() */ - + downgrade_write(&key_types_sem); + key_gc_keytype(ktype); + pr_notice("Key type %s unregistered\n", ktype->name); + up_read(&key_types_sem); +} EXPORT_SYMBOL(unregister_key_type); -/*****************************************************************************/ /* - * initialise the key management stuff + * Initialise the key management state. */ void __init key_init(void) { @@ -1009,6 +1091,7 @@ void __init key_init(void) list_add_tail(&key_type_keyring.link, &key_types_list); list_add_tail(&key_type_dead.link, &key_types_list); list_add_tail(&key_type_user.link, &key_types_list); + list_add_tail(&key_type_logon.link, &key_types_list); /* record the root user tracking */ rb_link_node(&root_key_user.node, @@ -1017,18 +1100,4 @@ void __init key_init(void) rb_insert_color(&root_key_user.node, &key_user_tree); - - /* record root's user standard keyrings */ - key_check(&root_user_keyring); - key_check(&root_session_keyring); - - __key_insert_serial(&root_user_keyring); - __key_insert_serial(&root_session_keyring); - - keyring_publish_name(&root_user_keyring); - keyring_publish_name(&root_session_keyring); - - /* link the two root keyrings together */ - key_link(&root_session_keyring, &root_user_keyring); - -} /* end key_init() */ +} diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index d9ca15c109c..cd5bd0cef25 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -1,4 +1,4 @@ -/* keyctl.c: userspace keyctl operations +/* Userspace key control operations * * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) @@ -14,11 +14,15 @@ #include <linux/sched.h> #include <linux/slab.h> #include <linux/syscalls.h> +#include <linux/key.h> #include <linux/keyctl.h> #include <linux/fs.h> #include <linux/capability.h> #include <linux/string.h> #include <linux/err.h> +#include <linux/vmalloc.h> +#include <linux/security.h> +#include <linux/uio.h> #include <asm/uaccess.h> #include "internal.h" @@ -29,42 +33,42 @@ static int key_get_type_from_user(char *type, int ret; ret = strncpy_from_user(type, _type, len); - if (ret < 0) - return -EFAULT; - + return ret; if (ret == 0 || ret >= len) return -EINVAL; - if (type[0] == '.') return -EPERM; - type[len - 1] = '\0'; - return 0; } -/*****************************************************************************/ /* - * extract the description of a new key from userspace and either add it as a - * new key to the specified keyring or update a matching key in that keyring - * - the keyring must be writable - * - returns the new key's serial number - * - implements add_key() + * Extract the description of a new key from userspace and either add it as a + * new key to the specified keyring or update a matching key in that keyring. + * + * If the description is NULL or an empty string, the key type is asked to + * generate one from the payload. + * + * The keyring must be writable so that we can attach the key to it. + * + * If successful, the new key's serial number is returned, otherwise an error + * code is returned. */ -asmlinkage long sys_add_key(const char __user *_type, - const char __user *_description, - const void __user *_payload, - size_t plen, - key_serial_t ringid) +SYSCALL_DEFINE5(add_key, const char __user *, _type, + const char __user *, _description, + const void __user *, _payload, + size_t, plen, + key_serial_t, ringid) { key_ref_t keyring_ref, key_ref; char type[32], *description; void *payload; long ret; + bool vm; ret = -EINVAL; - if (plen > 32767) + if (plen > 1024 * 1024 - 1) goto error; /* draw all the data into kernel space */ @@ -72,20 +76,34 @@ asmlinkage long sys_add_key(const char __user *_type, if (ret < 0) goto error; - description = strndup_user(_description, PAGE_SIZE); - if (IS_ERR(description)) { - ret = PTR_ERR(description); - goto error; + description = NULL; + if (_description) { + description = strndup_user(_description, PAGE_SIZE); + if (IS_ERR(description)) { + ret = PTR_ERR(description); + goto error; + } + if (!*description) { + kfree(description); + description = NULL; + } } /* pull the payload in if one was supplied */ payload = NULL; + vm = false; if (_payload) { ret = -ENOMEM; - payload = kmalloc(plen, GFP_KERNEL); - if (!payload) - goto error2; + payload = kmalloc(plen, GFP_KERNEL | __GFP_NOWARN); + if (!payload) { + if (plen <= PAGE_SIZE) + goto error2; + vm = true; + payload = vmalloc(plen); + if (!payload) + goto error2; + } ret = -EFAULT; if (copy_from_user(payload, _payload, plen) != 0) @@ -93,7 +111,7 @@ asmlinkage long sys_add_key(const char __user *_type, } /* find the target keyring (which must be writable) */ - keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); + keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); goto error3; @@ -102,7 +120,8 @@ asmlinkage long sys_add_key(const char __user *_type, /* create or update the requested key and add it to the target * keyring */ key_ref = key_create_or_update(keyring_ref, type, description, - payload, plen, KEY_ALLOC_IN_QUOTA); + payload, plen, KEY_PERM_UNDEF, + KEY_ALLOC_IN_QUOTA); if (!IS_ERR(key_ref)) { ret = key_ref_to_ptr(key_ref)->serial; key_ref_put(key_ref); @@ -113,33 +132,38 @@ asmlinkage long sys_add_key(const char __user *_type, key_ref_put(keyring_ref); error3: - kfree(payload); + if (!vm) + kfree(payload); + else + vfree(payload); error2: kfree(description); error: return ret; +} -} /* end sys_add_key() */ - -/*****************************************************************************/ /* - * search the process keyrings for a matching key - * - nested keyrings may also be searched if they have Search permission - * - if a key is found, it will be attached to the destination keyring if - * there's one specified - * - /sbin/request-key will be invoked if _callout_info is non-NULL - * - the _callout_info string will be passed to /sbin/request-key - * - if the _callout_info string is empty, it will be rendered as "-" - * - implements request_key() + * Search the process keyrings and keyring trees linked from those for a + * matching key. Keyrings must have appropriate Search permission to be + * searched. + * + * If a key is found, it will be attached to the destination keyring if there's + * one specified and the serial number of the key will be returned. + * + * If no key is found, /sbin/request-key will be invoked if _callout_info is + * non-NULL in an attempt to create a key. The _callout_info string will be + * passed to /sbin/request-key to aid with completing the request. If the + * _callout_info string is "" then it will be changed to "-". */ -asmlinkage long sys_request_key(const char __user *_type, - const char __user *_description, - const char __user *_callout_info, - key_serial_t destringid) +SYSCALL_DEFINE4(request_key, const char __user *, _type, + const char __user *, _description, + const char __user *, _callout_info, + key_serial_t, destringid) { struct key_type *ktype; struct key *key; key_ref_t dest_ref; + size_t callout_len; char type[32], *description, *callout_info; long ret; @@ -157,18 +181,21 @@ asmlinkage long sys_request_key(const char __user *_type, /* pull the callout info into kernel space */ callout_info = NULL; + callout_len = 0; if (_callout_info) { callout_info = strndup_user(_callout_info, PAGE_SIZE); if (IS_ERR(callout_info)) { ret = PTR_ERR(callout_info); goto error2; } + callout_len = strlen(callout_info); } /* get the destination keyring if specified */ dest_ref = NULL; if (destringid) { - dest_ref = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE); + dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE, + KEY_NEED_WRITE); if (IS_ERR(dest_ref)) { ret = PTR_ERR(dest_ref); goto error3; @@ -183,42 +210,50 @@ asmlinkage long sys_request_key(const char __user *_type, } /* do the search */ - key = request_key_and_link(ktype, description, callout_info, NULL, - key_ref_to_ptr(dest_ref), + key = request_key_and_link(ktype, description, callout_info, + callout_len, NULL, key_ref_to_ptr(dest_ref), KEY_ALLOC_IN_QUOTA); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error5; } + /* wait for the key to finish being constructed */ + ret = wait_for_key_construction(key, 1); + if (ret < 0) + goto error6; + ret = key->serial; +error6: key_put(key); - error5: +error5: key_type_put(ktype); - error4: +error4: key_ref_put(dest_ref); - error3: +error3: kfree(callout_info); - error2: +error2: kfree(description); - error: +error: return ret; +} -} /* end sys_request_key() */ - -/*****************************************************************************/ /* - * get the ID of the specified process keyring - * - the keyring must have search permission to be found - * - implements keyctl(KEYCTL_GET_KEYRING_ID) + * Get the ID of the specified process keyring. + * + * The requested keyring must have search permission to be found. + * + * If successful, the ID of the requested keyring will be returned. */ long keyctl_get_keyring_ID(key_serial_t id, int create) { key_ref_t key_ref; + unsigned long lflags; long ret; - key_ref = lookup_user_key(NULL, id, create, 0, KEY_SEARCH); + lflags = create ? KEY_LOOKUP_CREATE : 0; + key_ref = lookup_user_key(id, lflags, KEY_NEED_SEARCH); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error; @@ -226,15 +261,19 @@ long keyctl_get_keyring_ID(key_serial_t id, int create) ret = key_ref_to_ptr(key_ref)->serial; key_ref_put(key_ref); - error: +error: return ret; +} -} /* end keyctl_get_keyring_ID() */ - -/*****************************************************************************/ /* - * join the session keyring - * - implements keyctl(KEYCTL_JOIN_SESSION_KEYRING) + * Join a (named) session keyring. + * + * Create and join an anonymous session keyring or join a named session + * keyring, creating it if necessary. A named session keyring must have Search + * permission for it to be joined. Session keyrings without this permit will + * be skipped over. + * + * If successful, the ID of the joined session keyring will be returned. */ long keyctl_join_session_keyring(const char __user *_name) { @@ -253,17 +292,21 @@ long keyctl_join_session_keyring(const char __user *_name) /* join the session */ ret = join_session_keyring(name); + kfree(name); - error: +error: return ret; +} -} /* end keyctl_join_session_keyring() */ - -/*****************************************************************************/ /* - * update a key's data payload - * - the key must be writable - * - implements keyctl(KEYCTL_UPDATE) + * Update a key's data payload from the given data. + * + * The key must grant the caller Write permission and the key type must support + * updating for this to work. A negative key can be positively instantiated + * with this call. + * + * If successful, 0 will be returned. If the key type does not support + * updating, then -EOPNOTSUPP will be returned. */ long keyctl_update_key(key_serial_t id, const void __user *_payload, @@ -291,7 +334,7 @@ long keyctl_update_key(key_serial_t id, } /* find the target key (which must be writable) */ - key_ref = lookup_user_key(NULL, id, 0, 0, KEY_WRITE); + key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error2; @@ -301,83 +344,139 @@ long keyctl_update_key(key_serial_t id, ret = key_update(key_ref, payload, plen); key_ref_put(key_ref); - error2: +error2: kfree(payload); - error: +error: return ret; +} -} /* end keyctl_update_key() */ - -/*****************************************************************************/ /* - * revoke a key - * - the key must be writable - * - implements keyctl(KEYCTL_REVOKE) + * Revoke a key. + * + * The key must be grant the caller Write or Setattr permission for this to + * work. The key type should give up its quota claim when revoked. The key + * and any links to the key will be automatically garbage collected after a + * certain amount of time (/proc/sys/kernel/keys/gc_delay). + * + * If successful, 0 is returned. */ long keyctl_revoke_key(key_serial_t id) { key_ref_t key_ref; long ret; - key_ref = lookup_user_key(NULL, id, 0, 0, KEY_WRITE); + key_ref = lookup_user_key(id, 0, KEY_NEED_WRITE); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); - goto error; + if (ret != -EACCES) + goto error; + key_ref = lookup_user_key(id, 0, KEY_NEED_SETATTR); + if (IS_ERR(key_ref)) { + ret = PTR_ERR(key_ref); + goto error; + } } key_revoke(key_ref_to_ptr(key_ref)); ret = 0; key_ref_put(key_ref); - error: +error: return ret; +} + +/* + * Invalidate a key. + * + * The key must be grant the caller Invalidate permission for this to work. + * The key and any links to the key will be automatically garbage collected + * immediately. + * + * If successful, 0 is returned. + */ +long keyctl_invalidate_key(key_serial_t id) +{ + key_ref_t key_ref; + long ret; + + kenter("%d", id); + + key_ref = lookup_user_key(id, 0, KEY_NEED_SEARCH); + if (IS_ERR(key_ref)) { + ret = PTR_ERR(key_ref); + goto error; + } -} /* end keyctl_revoke_key() */ + key_invalidate(key_ref_to_ptr(key_ref)); + ret = 0; + + key_ref_put(key_ref); +error: + kleave(" = %ld", ret); + return ret; +} -/*****************************************************************************/ /* - * clear the specified process keyring - * - the keyring must be writable - * - implements keyctl(KEYCTL_CLEAR) + * Clear the specified keyring, creating an empty process keyring if one of the + * special keyring IDs is used. + * + * The keyring must grant the caller Write permission for this to work. If + * successful, 0 will be returned. */ long keyctl_keyring_clear(key_serial_t ringid) { key_ref_t keyring_ref; long ret; - keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); + keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); + + /* Root is permitted to invalidate certain special keyrings */ + if (capable(CAP_SYS_ADMIN)) { + keyring_ref = lookup_user_key(ringid, 0, 0); + if (IS_ERR(keyring_ref)) + goto error; + if (test_bit(KEY_FLAG_ROOT_CAN_CLEAR, + &key_ref_to_ptr(keyring_ref)->flags)) + goto clear; + goto error_put; + } + goto error; } +clear: ret = keyring_clear(key_ref_to_ptr(keyring_ref)); - +error_put: key_ref_put(keyring_ref); - error: +error: return ret; +} -} /* end keyctl_keyring_clear() */ - -/*****************************************************************************/ /* - * link a key into a keyring - * - the keyring must be writable - * - the key must be linkable - * - implements keyctl(KEYCTL_LINK) + * Create a link from a keyring to a key if there's no matching key in the + * keyring, otherwise replace the link to the matching key with a link to the + * new key. + * + * The key must grant the caller Link permission and the the keyring must grant + * the caller Write permission. Furthermore, if an additional link is created, + * the keyring's quota will be extended. + * + * If successful, 0 will be returned. */ long keyctl_keyring_link(key_serial_t id, key_serial_t ringid) { key_ref_t keyring_ref, key_ref; long ret; - keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); + keyring_ref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); goto error; } - key_ref = lookup_user_key(NULL, id, 1, 0, KEY_LINK); + key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE, KEY_NEED_LINK); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error2; @@ -386,32 +485,33 @@ long keyctl_keyring_link(key_serial_t id, key_serial_t ringid) ret = key_link(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref)); key_ref_put(key_ref); - error2: +error2: key_ref_put(keyring_ref); - error: +error: return ret; +} -} /* end keyctl_keyring_link() */ - -/*****************************************************************************/ /* - * unlink the first attachment of a key from a keyring - * - the keyring must be writable - * - we don't need any permissions on the key - * - implements keyctl(KEYCTL_UNLINK) + * Unlink a key from a keyring. + * + * The keyring must grant the caller Write permission for this to work; the key + * itself need not grant the caller anything. If the last link to a key is + * removed then that key will be scheduled for destruction. + * + * If successful, 0 will be returned. */ long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid) { key_ref_t keyring_ref, key_ref; long ret; - keyring_ref = lookup_user_key(NULL, ringid, 0, 0, KEY_WRITE); + keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_WRITE); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); goto error; } - key_ref = lookup_user_key(NULL, id, 0, 0, 0); + key_ref = lookup_user_key(id, KEY_LOOKUP_FOR_UNLINK, 0); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error2; @@ -420,23 +520,24 @@ long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid) ret = key_unlink(key_ref_to_ptr(keyring_ref), key_ref_to_ptr(key_ref)); key_ref_put(key_ref); - error2: +error2: key_ref_put(keyring_ref); - error: +error: return ret; +} -} /* end keyctl_keyring_unlink() */ - -/*****************************************************************************/ /* - * describe a user key - * - the key must have view permission - * - if there's a buffer, we place up to buflen bytes of data into it - * - unless there's an error, we return the amount of description available, - * irrespective of how much we may have copied - * - the description is formatted thus: + * Return a description of a key to userspace. + * + * The key must grant the caller View permission for this to work. + * + * If there's a buffer, we place up to buflen bytes of data into it formatted + * in the following way: + * * type;uid;gid;perm;description<NUL> - * - implements keyctl(KEYCTL_DESCRIBE) + * + * If successful, we return the amount of description available, irrespective + * of how much we may have copied into the buffer. */ long keyctl_describe_key(key_serial_t keyid, char __user *buffer, @@ -447,7 +548,7 @@ long keyctl_describe_key(key_serial_t keyid, char *tmpbuf; long ret; - key_ref = lookup_user_key(NULL, keyid, 0, 1, KEY_VIEW); + key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW); if (IS_ERR(key_ref)) { /* viewing a key under construction is permitted if we have the * authorisation token handy */ @@ -455,8 +556,9 @@ long keyctl_describe_key(key_serial_t keyid, instkey = key_get_instantiation_authkey(keyid); if (!IS_ERR(instkey)) { key_put(instkey); - key_ref = lookup_user_key(NULL, keyid, - 0, 1, 0); + key_ref = lookup_user_key(keyid, + KEY_LOOKUP_PARTIAL, + 0); if (!IS_ERR(key_ref)) goto okay; } @@ -477,13 +579,11 @@ okay: ret = snprintf(tmpbuf, PAGE_SIZE - 1, "%s;%d;%d;%08x;%s", - key_ref_to_ptr(key_ref)->type->name, - key_ref_to_ptr(key_ref)->uid, - key_ref_to_ptr(key_ref)->gid, - key_ref_to_ptr(key_ref)->perm, - key_ref_to_ptr(key_ref)->description ? - key_ref_to_ptr(key_ref)->description : "" - ); + key->type->name, + from_kuid_munged(current_user_ns(), key->uid), + from_kgid_munged(current_user_ns(), key->gid), + key->perm, + key->description ?: ""); /* include a NUL char at the end of the data */ if (ret > PAGE_SIZE - 1) @@ -501,22 +601,21 @@ okay: } kfree(tmpbuf); - error2: +error2: key_ref_put(key_ref); - error: +error: return ret; +} -} /* end keyctl_describe_key() */ - -/*****************************************************************************/ /* - * search the specified keyring for a matching key - * - the start keyring must be searchable - * - nested keyrings may also be searched if they are searchable - * - only keys with search permission may be found - * - if a key is found, it will be attached to the destination keyring if - * there's one specified - * - implements keyctl(KEYCTL_SEARCH) + * Search the specified keyring and any keyrings it links to for a matching + * key. Only keyrings that grant the caller Search permission will be searched + * (this includes the starting keyring). Only keys with Search permission can + * be found. + * + * If successful, the found key will be linked to the destination keyring if + * supplied and the key has Link permission, and the found key ID will be + * returned. */ long keyctl_keyring_search(key_serial_t ringid, const char __user *_type, @@ -540,7 +639,7 @@ long keyctl_keyring_search(key_serial_t ringid, } /* get the keyring at which to begin the search */ - keyring_ref = lookup_user_key(NULL, ringid, 0, 0, KEY_SEARCH); + keyring_ref = lookup_user_key(ringid, 0, KEY_NEED_SEARCH); if (IS_ERR(keyring_ref)) { ret = PTR_ERR(keyring_ref); goto error2; @@ -549,7 +648,8 @@ long keyctl_keyring_search(key_serial_t ringid, /* get the destination keyring if specified */ dest_ref = NULL; if (destringid) { - dest_ref = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE); + dest_ref = lookup_user_key(destringid, KEY_LOOKUP_CREATE, + KEY_NEED_WRITE); if (IS_ERR(dest_ref)) { ret = PTR_ERR(dest_ref); goto error3; @@ -576,7 +676,7 @@ long keyctl_keyring_search(key_serial_t ringid, /* link the resulting key to the destination keyring if we can */ if (dest_ref) { - ret = key_permission(key_ref, KEY_LINK); + ret = key_permission(key_ref, KEY_NEED_LINK); if (ret < 0) goto error6; @@ -587,30 +687,29 @@ long keyctl_keyring_search(key_serial_t ringid, ret = key_ref_to_ptr(key_ref)->serial; - error6: +error6: key_ref_put(key_ref); - error5: +error5: key_type_put(ktype); - error4: +error4: key_ref_put(dest_ref); - error3: +error3: key_ref_put(keyring_ref); - error2: +error2: kfree(description); - error: +error: return ret; +} -} /* end keyctl_keyring_search() */ - -/*****************************************************************************/ /* - * read a user key's payload - * - the keyring must be readable or the key must be searchable from the - * process's keyrings - * - if there's a buffer, we place up to buflen bytes of data into it - * - unless there's an error, we return the amount of data in the key, - * irrespective of how much we may have copied - * - implements keyctl(KEYCTL_READ) + * Read a key's payload. + * + * The key must either grant the caller Read permission, or it must grant the + * caller Search permission when searched for from the process keyrings. + * + * If successful, we place up to buflen bytes of data into the buffer, if one + * is provided, and return the amount of data that is available in the key, + * irrespective of how much we copied into the buffer. */ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) { @@ -619,7 +718,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) long ret; /* find the key first */ - key_ref = lookup_user_key(NULL, keyid, 0, 0, 0); + key_ref = lookup_user_key(keyid, 0, 0); if (IS_ERR(key_ref)) { ret = -ENOKEY; goto error; @@ -628,7 +727,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) key = key_ref_to_ptr(key_ref); /* see if we can read it directly */ - ret = key_permission(key_ref, KEY_READ); + ret = key_permission(key_ref, KEY_NEED_READ); if (ret == 0) goto can_read_key; if (ret != -EACCES) @@ -644,7 +743,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) } /* the key is probably readable - now try to read it */ - can_read_key: +can_read_key: ret = key_validate(key); if (ret == 0) { ret = -EOPNOTSUPP; @@ -657,32 +756,50 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) } } - error2: +error2: key_put(key); - error: +error: return ret; +} -} /* end keyctl_read_key() */ - -/*****************************************************************************/ /* - * change the ownership of a key - * - the keyring owned by the changer - * - if the uid or gid is -1, then that parameter is not changed - * - implements keyctl(KEYCTL_CHOWN) + * Change the ownership of a key + * + * The key must grant the caller Setattr permission for this to work, though + * the key need not be fully instantiated yet. For the UID to be changed, or + * for the GID to be changed to a group the caller is not a member of, the + * caller must have sysadmin capability. If either uid or gid is -1 then that + * attribute is not changed. + * + * If the UID is to be changed, the new user must have sufficient quota to + * accept the key. The quota deduction will be removed from the old user to + * the new user should the attribute be changed. + * + * If successful, 0 will be returned. */ -long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) +long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group) { struct key_user *newowner, *zapowner = NULL; struct key *key; key_ref_t key_ref; long ret; + kuid_t uid; + kgid_t gid; + + uid = make_kuid(current_user_ns(), user); + gid = make_kgid(current_user_ns(), group); + ret = -EINVAL; + if ((user != (uid_t) -1) && !uid_valid(uid)) + goto error; + if ((group != (gid_t) -1) && !gid_valid(gid)) + goto error; ret = 0; - if (uid == (uid_t) -1 && gid == (gid_t) -1) + if (user == (uid_t) -1 && group == (gid_t) -1) goto error; - key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR); + key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, + KEY_NEED_SETATTR); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error; @@ -696,17 +813,17 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) if (!capable(CAP_SYS_ADMIN)) { /* only the sysadmin can chown a key to some other UID */ - if (uid != (uid_t) -1 && key->uid != uid) + if (user != (uid_t) -1 && !uid_eq(key->uid, uid)) goto error_put; /* only the sysadmin can set the key's GID to a group other * than one of those that the current process subscribes to */ - if (gid != (gid_t) -1 && gid != key->gid && !in_group_p(gid)) + if (group != (gid_t) -1 && !gid_eq(gid, key->gid) && !in_group_p(gid)) goto error_put; } /* change the UID */ - if (uid != (uid_t) -1 && uid != key->uid) { + if (user != (uid_t) -1 && !uid_eq(uid, key->uid)) { ret = -ENOMEM; newowner = key_user_lookup(uid); if (!newowner) @@ -714,10 +831,16 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) /* transfer the quota burden to the new user */ if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { + unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxkeys : key_quota_maxkeys; + unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxbytes : key_quota_maxbytes; + spin_lock(&newowner->lock); - if (newowner->qnkeys + 1 >= KEYQUOTA_MAX_KEYS || - newowner->qnbytes + key->quotalen >= - KEYQUOTA_MAX_BYTES) + if (newowner->qnkeys + 1 >= maxkeys || + newowner->qnbytes + key->quotalen >= maxbytes || + newowner->qnbytes + key->quotalen < + newowner->qnbytes) goto quota_overrun; newowner->qnkeys++; @@ -744,7 +867,7 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid) } /* change the GID */ - if (gid != (gid_t) -1) + if (group != (gid_t) -1) key->gid = gid; ret = 0; @@ -762,14 +885,14 @@ quota_overrun: zapowner = newowner; ret = -EDQUOT; goto error_put; +} -} /* end keyctl_chown_key() */ - -/*****************************************************************************/ /* - * change the permission mask on a key - * - the keyring owned by the changer - * - implements keyctl(KEYCTL_SETPERM) + * Change the permission mask on a key. + * + * The key must grant the caller Setattr permission for this to work, though + * the key need not be fully instantiated yet. If the caller does not have + * sysadmin capability, it may only change the permission on keys that it owns. */ long keyctl_setperm_key(key_serial_t id, key_perm_t perm) { @@ -781,7 +904,8 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm) if (perm & ~(KEY_POS_ALL | KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL)) goto error; - key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR); + key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, + KEY_NEED_SETATTR); if (IS_ERR(key_ref)) { ret = PTR_ERR(key_ref); goto error; @@ -794,7 +918,7 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm) down_write(&key->sem); /* if we're not the sysadmin, we can only change a key that we own */ - if (capable(CAP_SYS_ADMIN) || key->uid == current->fsuid) { + if (capable(CAP_SYS_ADMIN) || uid_eq(key->uid, current_fsuid())) { key->perm = perm; ret = 0; } @@ -803,33 +927,110 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm) key_put(key); error: return ret; +} + +/* + * Get the destination keyring for instantiation and check that the caller has + * Write permission on it. + */ +static long get_instantiation_keyring(key_serial_t ringid, + struct request_key_auth *rka, + struct key **_dest_keyring) +{ + key_ref_t dkref; + + *_dest_keyring = NULL; + + /* just return a NULL pointer if we weren't asked to make a link */ + if (ringid == 0) + return 0; + + /* if a specific keyring is nominated by ID, then use that */ + if (ringid > 0) { + dkref = lookup_user_key(ringid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); + if (IS_ERR(dkref)) + return PTR_ERR(dkref); + *_dest_keyring = key_ref_to_ptr(dkref); + return 0; + } + + if (ringid == KEY_SPEC_REQKEY_AUTH_KEY) + return -EINVAL; + + /* otherwise specify the destination keyring recorded in the + * authorisation key (any KEY_SPEC_*_KEYRING) */ + if (ringid >= KEY_SPEC_REQUESTOR_KEYRING) { + *_dest_keyring = key_get(rka->dest_keyring); + return 0; + } -} /* end keyctl_setperm_key() */ + return -ENOKEY; +} -/*****************************************************************************/ /* - * instantiate the key with the specified payload, and, if one is given, link - * the key into the keyring + * Change the request_key authorisation key on the current process. */ -long keyctl_instantiate_key(key_serial_t id, - const void __user *_payload, - size_t plen, - key_serial_t ringid) +static int keyctl_change_reqkey_auth(struct key *key) +{ + struct cred *new; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + + key_put(new->request_key_auth); + new->request_key_auth = key_get(key); + + return commit_creds(new); +} + +/* + * Copy the iovec data from userspace + */ +static long copy_from_user_iovec(void *buffer, const struct iovec *iov, + unsigned ioc) +{ + for (; ioc > 0; ioc--) { + if (copy_from_user(buffer, iov->iov_base, iov->iov_len) != 0) + return -EFAULT; + buffer += iov->iov_len; + iov++; + } + return 0; +} + +/* + * Instantiate a key with the specified payload and link the key into the + * destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * If successful, 0 will be returned. + */ +long keyctl_instantiate_key_common(key_serial_t id, + const struct iovec *payload_iov, + unsigned ioc, + size_t plen, + key_serial_t ringid) { + const struct cred *cred = current_cred(); struct request_key_auth *rka; - struct key *instkey; - key_ref_t keyring_ref; + struct key *instkey, *dest_keyring; void *payload; long ret; + bool vm = false; + + kenter("%d,,%zu,%d", id, plen, ringid); ret = -EINVAL; - if (plen > 32767) + if (plen > 1024 * 1024 - 1) goto error; /* the appropriate instantiation authorisation key must have been * assumed before calling this */ ret = -EPERM; - instkey = current->request_key_auth; + instkey = cred->request_key_auth; if (!instkey) goto error; @@ -840,65 +1041,173 @@ long keyctl_instantiate_key(key_serial_t id, /* pull the payload in if one was supplied */ payload = NULL; - if (_payload) { + if (payload_iov) { ret = -ENOMEM; payload = kmalloc(plen, GFP_KERNEL); - if (!payload) - goto error; + if (!payload) { + if (plen <= PAGE_SIZE) + goto error; + vm = true; + payload = vmalloc(plen); + if (!payload) + goto error; + } - ret = -EFAULT; - if (copy_from_user(payload, _payload, plen) != 0) + ret = copy_from_user_iovec(payload, payload_iov, ioc); + if (ret < 0) goto error2; } /* find the destination keyring amongst those belonging to the * requesting task */ - keyring_ref = NULL; - if (ringid) { - keyring_ref = lookup_user_key(rka->context, ringid, 1, 0, - KEY_WRITE); - if (IS_ERR(keyring_ref)) { - ret = PTR_ERR(keyring_ref); - goto error2; - } - } + ret = get_instantiation_keyring(ringid, rka, &dest_keyring); + if (ret < 0) + goto error2; /* instantiate the key and link it into a keyring */ ret = key_instantiate_and_link(rka->target_key, payload, plen, - key_ref_to_ptr(keyring_ref), instkey); + dest_keyring, instkey); - key_ref_put(keyring_ref); + key_put(dest_keyring); /* discard the assumed authority if it's just been disabled by * instantiation of the key */ - if (ret == 0) { - key_put(current->request_key_auth); - current->request_key_auth = NULL; - } + if (ret == 0) + keyctl_change_reqkey_auth(NULL); error2: - kfree(payload); + if (!vm) + kfree(payload); + else + vfree(payload); error: return ret; +} + +/* + * Instantiate a key with the specified payload and link the key into the + * destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * If successful, 0 will be returned. + */ +long keyctl_instantiate_key(key_serial_t id, + const void __user *_payload, + size_t plen, + key_serial_t ringid) +{ + if (_payload && plen) { + struct iovec iov[1] = { + [0].iov_base = (void __user *)_payload, + [0].iov_len = plen + }; + + return keyctl_instantiate_key_common(id, iov, 1, plen, ringid); + } + + return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid); +} + +/* + * Instantiate a key with the specified multipart payload and link the key into + * the destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * If successful, 0 will be returned. + */ +long keyctl_instantiate_key_iov(key_serial_t id, + const struct iovec __user *_payload_iov, + unsigned ioc, + key_serial_t ringid) +{ + struct iovec iovstack[UIO_FASTIOV], *iov = iovstack; + long ret; + + if (!_payload_iov || !ioc) + goto no_payload; + + ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc, + ARRAY_SIZE(iovstack), iovstack, &iov); + if (ret < 0) + goto err; + if (ret == 0) + goto no_payload_free; + + ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid); +err: + if (iov != iovstack) + kfree(iov); + return ret; -} /* end keyctl_instantiate_key() */ +no_payload_free: + if (iov != iovstack) + kfree(iov); +no_payload: + return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid); +} -/*****************************************************************************/ /* - * negatively instantiate the key with the given timeout (in seconds), and, if - * one is given, link the key into the keyring + * Negatively instantiate the key with the given timeout (in seconds) and link + * the key into the destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * The key and any links to the key will be automatically garbage collected + * after the timeout expires. + * + * Negative keys are used to rate limit repeated request_key() calls by causing + * them to return -ENOKEY until the negative key expires. + * + * If successful, 0 will be returned. */ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) { + return keyctl_reject_key(id, timeout, ENOKEY, ringid); +} + +/* + * Negatively instantiate the key with the given timeout (in seconds) and error + * code and link the key into the destination keyring if one is given. + * + * The caller must have the appropriate instantiation permit set for this to + * work (see keyctl_assume_authority). No other permissions are required. + * + * The key and any links to the key will be automatically garbage collected + * after the timeout expires. + * + * Negative keys are used to rate limit repeated request_key() calls by causing + * them to return the specified error code until the negative key expires. + * + * If successful, 0 will be returned. + */ +long keyctl_reject_key(key_serial_t id, unsigned timeout, unsigned error, + key_serial_t ringid) +{ + const struct cred *cred = current_cred(); struct request_key_auth *rka; - struct key *instkey; - key_ref_t keyring_ref; + struct key *instkey, *dest_keyring; long ret; + kenter("%d,%u,%u,%d", id, timeout, error, ringid); + + /* must be a valid error code and mustn't be a kernel special */ + if (error <= 0 || + error >= MAX_ERRNO || + error == ERESTARTSYS || + error == ERESTARTNOINTR || + error == ERESTARTNOHAND || + error == ERESTART_RESTARTBLOCK) + return -EINVAL; + /* the appropriate instantiation authorisation key must have been * assumed before calling this */ ret = -EPERM; - instkey = current->request_key_auth; + instkey = cred->request_key_auth; if (!instkey) goto error; @@ -908,114 +1217,150 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid) /* find the destination keyring if present (which must also be * writable) */ - keyring_ref = NULL; - if (ringid) { - keyring_ref = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE); - if (IS_ERR(keyring_ref)) { - ret = PTR_ERR(keyring_ref); - goto error; - } - } + ret = get_instantiation_keyring(ringid, rka, &dest_keyring); + if (ret < 0) + goto error; /* instantiate the key and link it into a keyring */ - ret = key_negate_and_link(rka->target_key, timeout, - key_ref_to_ptr(keyring_ref), instkey); + ret = key_reject_and_link(rka->target_key, timeout, error, + dest_keyring, instkey); - key_ref_put(keyring_ref); + key_put(dest_keyring); /* discard the assumed authority if it's just been disabled by * instantiation of the key */ - if (ret == 0) { - key_put(current->request_key_auth); - current->request_key_auth = NULL; - } + if (ret == 0) + keyctl_change_reqkey_auth(NULL); error: return ret; +} -} /* end keyctl_negate_key() */ - -/*****************************************************************************/ /* - * set the default keyring in which request_key() will cache keys - * - return the old setting + * Read or set the default keyring in which request_key() will cache keys and + * return the old setting. + * + * If a process keyring is specified then this will be created if it doesn't + * yet exist. The old setting will be returned if successful. */ long keyctl_set_reqkey_keyring(int reqkey_defl) { - int ret; + struct cred *new; + int ret, old_setting; + + old_setting = current_cred_xxx(jit_keyring); + + if (reqkey_defl == KEY_REQKEY_DEFL_NO_CHANGE) + return old_setting; + + new = prepare_creds(); + if (!new) + return -ENOMEM; switch (reqkey_defl) { case KEY_REQKEY_DEFL_THREAD_KEYRING: - ret = install_thread_keyring(current); + ret = install_thread_keyring_to_cred(new); if (ret < 0) - return ret; + goto error; goto set; case KEY_REQKEY_DEFL_PROCESS_KEYRING: - ret = install_process_keyring(current); - if (ret < 0) - return ret; + ret = install_process_keyring_to_cred(new); + if (ret < 0) { + if (ret != -EEXIST) + goto error; + ret = 0; + } + goto set; case KEY_REQKEY_DEFL_DEFAULT: case KEY_REQKEY_DEFL_SESSION_KEYRING: case KEY_REQKEY_DEFL_USER_KEYRING: case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: - set: - current->jit_keyring = reqkey_defl; + case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: + goto set; case KEY_REQKEY_DEFL_NO_CHANGE: - return current->jit_keyring; - case KEY_REQKEY_DEFL_GROUP_KEYRING: default: - return -EINVAL; + ret = -EINVAL; + goto error; } -} /* end keyctl_set_reqkey_keyring() */ +set: + new->jit_keyring = reqkey_defl; + commit_creds(new); + return old_setting; +error: + abort_creds(new); + return ret; +} -/*****************************************************************************/ /* - * set or clear the timeout for a key + * Set or clear the timeout on a key. + * + * Either the key must grant the caller Setattr permission or else the caller + * must hold an instantiation authorisation token for the key. + * + * The timeout is either 0 to clear the timeout, or a number of seconds from + * the current time. The key and any links to the key will be automatically + * garbage collected after the timeout expires. + * + * If successful, 0 is returned. */ long keyctl_set_timeout(key_serial_t id, unsigned timeout) { - struct timespec now; - struct key *key; + struct key *key, *instkey; key_ref_t key_ref; - time_t expiry; long ret; - key_ref = lookup_user_key(NULL, id, 1, 1, KEY_SETATTR); + key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL, + KEY_NEED_SETATTR); if (IS_ERR(key_ref)) { + /* setting the timeout on a key under construction is permitted + * if we have the authorisation token handy */ + if (PTR_ERR(key_ref) == -EACCES) { + instkey = key_get_instantiation_authkey(id); + if (!IS_ERR(instkey)) { + key_put(instkey); + key_ref = lookup_user_key(id, + KEY_LOOKUP_PARTIAL, + 0); + if (!IS_ERR(key_ref)) + goto okay; + } + } + ret = PTR_ERR(key_ref); goto error; } +okay: key = key_ref_to_ptr(key_ref); - - /* make the changes with the locks held to prevent races */ - down_write(&key->sem); - - expiry = 0; - if (timeout > 0) { - now = current_kernel_time(); - expiry = now.tv_sec + timeout; - } - - key->expiry = expiry; - - up_write(&key->sem); + key_set_timeout(key, timeout); key_put(key); ret = 0; error: return ret; +} -} /* end keyctl_set_timeout() */ - -/*****************************************************************************/ /* - * assume the authority to instantiate the specified key + * Assume (or clear) the authority to instantiate the specified key. + * + * This sets the authoritative token currently in force for key instantiation. + * This must be done for a key to be instantiated. It has the effect of making + * available all the keys from the caller of the request_key() that created a + * key to request_key() calls made by the caller of this function. + * + * The caller must have the instantiation key in their process keyrings with a + * Search permission grant available to the caller. + * + * If the ID given is 0, then the setting will be cleared and 0 returned. + * + * If the ID given has a matching an authorisation key, then that key will be + * set and its ID will be returned. The authorisation key can be read to get + * the callout information passed to request_key(). */ long keyctl_assume_authority(key_serial_t id) { @@ -1029,9 +1374,7 @@ long keyctl_assume_authority(key_serial_t id) /* we divest ourselves of authority if given an ID of 0 */ if (id == 0) { - key_put(current->request_key_auth); - current->request_key_auth = NULL; - ret = 0; + ret = keyctl_change_reqkey_auth(NULL); goto error; } @@ -1046,21 +1389,186 @@ long keyctl_assume_authority(key_serial_t id) goto error; } - key_put(current->request_key_auth); - current->request_key_auth = authkey; - ret = authkey->serial; + ret = keyctl_change_reqkey_auth(authkey); + if (ret < 0) + goto error; + key_put(authkey); + ret = authkey->serial; error: return ret; +} -} /* end keyctl_assume_authority() */ +/* + * Get a key's the LSM security label. + * + * The key must grant the caller View permission for this to work. + * + * If there's a buffer, then up to buflen bytes of data will be placed into it. + * + * If successful, the amount of information available will be returned, + * irrespective of how much was copied (including the terminal NUL). + */ +long keyctl_get_security(key_serial_t keyid, + char __user *buffer, + size_t buflen) +{ + struct key *key, *instkey; + key_ref_t key_ref; + char *context; + long ret; + + key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW); + if (IS_ERR(key_ref)) { + if (PTR_ERR(key_ref) != -EACCES) + return PTR_ERR(key_ref); + + /* viewing a key under construction is also permitted if we + * have the authorisation token handy */ + instkey = key_get_instantiation_authkey(keyid); + if (IS_ERR(instkey)) + return PTR_ERR(instkey); + key_put(instkey); + + key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, 0); + if (IS_ERR(key_ref)) + return PTR_ERR(key_ref); + } + + key = key_ref_to_ptr(key_ref); + ret = security_key_getsecurity(key, &context); + if (ret == 0) { + /* if no information was returned, give userspace an empty + * string */ + ret = 1; + if (buffer && buflen > 0 && + copy_to_user(buffer, "", 1) != 0) + ret = -EFAULT; + } else if (ret > 0) { + /* return as much data as there's room for */ + if (buffer && buflen > 0) { + if (buflen > ret) + buflen = ret; + + if (copy_to_user(buffer, context, buflen) != 0) + ret = -EFAULT; + } + + kfree(context); + } + + key_ref_put(key_ref); + return ret; +} -/*****************************************************************************/ /* - * the key control system call + * Attempt to install the calling process's session keyring on the process's + * parent process. + * + * The keyring must exist and must grant the caller LINK permission, and the + * parent process must be single-threaded and must have the same effective + * ownership as this process and mustn't be SUID/SGID. + * + * The keyring will be emplaced on the parent when it next resumes userspace. + * + * If successful, 0 will be returned. */ -asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3, - unsigned long arg4, unsigned long arg5) +long keyctl_session_to_parent(void) +{ + struct task_struct *me, *parent; + const struct cred *mycred, *pcred; + struct callback_head *newwork, *oldwork; + key_ref_t keyring_r; + struct cred *cred; + int ret; + + keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_NEED_LINK); + if (IS_ERR(keyring_r)) + return PTR_ERR(keyring_r); + + ret = -ENOMEM; + + /* our parent is going to need a new cred struct, a new tgcred struct + * and new security data, so we allocate them here to prevent ENOMEM in + * our parent */ + cred = cred_alloc_blank(); + if (!cred) + goto error_keyring; + newwork = &cred->rcu; + + cred->session_keyring = key_ref_to_ptr(keyring_r); + keyring_r = NULL; + init_task_work(newwork, key_change_session_keyring); + + me = current; + rcu_read_lock(); + write_lock_irq(&tasklist_lock); + + ret = -EPERM; + oldwork = NULL; + parent = me->real_parent; + + /* the parent mustn't be init and mustn't be a kernel thread */ + if (parent->pid <= 1 || !parent->mm) + goto unlock; + + /* the parent must be single threaded */ + if (!thread_group_empty(parent)) + goto unlock; + + /* the parent and the child must have different session keyrings or + * there's no point */ + mycred = current_cred(); + pcred = __task_cred(parent); + if (mycred == pcred || + mycred->session_keyring == pcred->session_keyring) { + ret = 0; + goto unlock; + } + + /* the parent must have the same effective ownership and mustn't be + * SUID/SGID */ + if (!uid_eq(pcred->uid, mycred->euid) || + !uid_eq(pcred->euid, mycred->euid) || + !uid_eq(pcred->suid, mycred->euid) || + !gid_eq(pcred->gid, mycred->egid) || + !gid_eq(pcred->egid, mycred->egid) || + !gid_eq(pcred->sgid, mycred->egid)) + goto unlock; + + /* the keyrings must have the same UID */ + if ((pcred->session_keyring && + !uid_eq(pcred->session_keyring->uid, mycred->euid)) || + !uid_eq(mycred->session_keyring->uid, mycred->euid)) + goto unlock; + + /* cancel an already pending keyring replacement */ + oldwork = task_work_cancel(parent, key_change_session_keyring); + + /* the replacement session keyring is applied just prior to userspace + * restarting */ + ret = task_work_add(parent, newwork, true); + if (!ret) + newwork = NULL; +unlock: + write_unlock_irq(&tasklist_lock); + rcu_read_unlock(); + if (oldwork) + put_cred(container_of(oldwork, struct cred, rcu)); + if (newwork) + put_cred(cred); + return ret; + +error_keyring: + key_ref_put(keyring_r); + return ret; +} + +/* + * The key control system call + */ +SYSCALL_DEFINE5(keyctl, int, option, unsigned long, arg2, unsigned long, arg3, + unsigned long, arg4, unsigned long, arg5) { switch (option) { case KEYCTL_GET_KEYRING_ID: @@ -1135,8 +1643,34 @@ asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3, case KEYCTL_ASSUME_AUTHORITY: return keyctl_assume_authority((key_serial_t) arg2); + case KEYCTL_GET_SECURITY: + return keyctl_get_security((key_serial_t) arg2, + (char __user *) arg3, + (size_t) arg4); + + case KEYCTL_SESSION_TO_PARENT: + return keyctl_session_to_parent(); + + case KEYCTL_REJECT: + return keyctl_reject_key((key_serial_t) arg2, + (unsigned) arg3, + (unsigned) arg4, + (key_serial_t) arg5); + + case KEYCTL_INSTANTIATE_IOV: + return keyctl_instantiate_key_iov( + (key_serial_t) arg2, + (const struct iovec __user *) arg3, + (unsigned) arg4, + (key_serial_t) arg5); + + case KEYCTL_INVALIDATE: + return keyctl_invalidate_key((key_serial_t) arg2); + + case KEYCTL_GET_PERSISTENT: + return keyctl_get_persistent((uid_t)arg2, (key_serial_t)arg3); + default: return -EOPNOTSUPP; } - -} /* end sys_keyctl() */ +} diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 88292e3dee9..9cf2575f0d9 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -1,6 +1,6 @@ -/* keyring.c: keyring handling +/* Keyring handling * - * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004-2005, 2008, 2013 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -16,20 +16,45 @@ #include <linux/security.h> #include <linux/seq_file.h> #include <linux/err.h> -#include <asm/uaccess.h> +#include <keys/keyring-type.h> +#include <keys/user-type.h> +#include <linux/assoc_array_priv.h> +#include <linux/uaccess.h> #include "internal.h" /* - * when plumbing the depths of the key tree, this sets a hard limit set on how - * deep we're willing to go + * When plumbing the depths of the key tree, this sets a hard limit + * set on how deep we're willing to go. */ #define KEYRING_SEARCH_MAX_DEPTH 6 /* - * we keep all named keyrings in a hash to speed looking them up + * We keep all named keyrings in a hash to speed looking them up. */ #define KEYRING_NAME_HASH_SIZE (1 << 5) +/* + * We mark pointers we pass to the associative array with bit 1 set if + * they're keyrings and clear otherwise. + */ +#define KEYRING_PTR_SUBTYPE 0x2UL + +static inline bool keyring_ptr_is_keyring(const struct assoc_array_ptr *x) +{ + return (unsigned long)x & KEYRING_PTR_SUBTYPE; +} +static inline struct key *keyring_ptr_to_key(const struct assoc_array_ptr *x) +{ + void *object = assoc_array_ptr_to_leaf(x); + return (struct key *)((unsigned long)object & ~KEYRING_PTR_SUBTYPE); +} +static inline void *keyring_key_to_ptr(struct key *key) +{ + if (key->type == &key_type_keyring) + return (void *)((unsigned long)key | KEYRING_PTR_SUBTYPE); + return key; +} + static struct list_head keyring_name_hash[KEYRING_NAME_HASH_SIZE]; static DEFINE_RWLOCK(keyring_name_lock); @@ -38,17 +63,18 @@ static inline unsigned keyring_hash(const char *desc) unsigned bucket = 0; for (; *desc; desc++) - bucket += (unsigned char) *desc; + bucket += (unsigned char)*desc; return bucket & (KEYRING_NAME_HASH_SIZE - 1); } /* - * the keyring type definition + * The keyring key type definition. Keyrings are simply keys of this type and + * can be treated as ordinary keys in addition to having their own special + * operations. */ static int keyring_instantiate(struct key *keyring, - const void *data, size_t datalen); -static int keyring_match(const struct key *keyring, const void *criterion); + struct key_preparsed_payload *prep); static void keyring_revoke(struct key *keyring); static void keyring_destroy(struct key *keyring); static void keyring_describe(const struct key *keyring, struct seq_file *m); @@ -57,29 +83,27 @@ static long keyring_read(const struct key *keyring, struct key_type key_type_keyring = { .name = "keyring", - .def_datalen = sizeof(struct keyring_list), + .def_datalen = 0, .instantiate = keyring_instantiate, - .match = keyring_match, + .match = user_match, .revoke = keyring_revoke, .destroy = keyring_destroy, .describe = keyring_describe, .read = keyring_read, }; - EXPORT_SYMBOL(key_type_keyring); /* - * semaphore to serialise link/link calls to prevent two link calls in parallel - * introducing a cycle + * Semaphore to serialise link/link calls to prevent two link calls in parallel + * introducing a cycle. */ static DECLARE_RWSEM(keyring_serialise_link_sem); -/*****************************************************************************/ /* - * publish the name of a keyring so that it can be found by name (if it has - * one) + * Publish the name of a keyring so that it can be found by name (if it has + * one). */ -void keyring_publish_name(struct key *keyring) +static void keyring_publish_name(struct key *keyring) { int bucket; @@ -96,50 +120,259 @@ void keyring_publish_name(struct key *keyring) write_unlock(&keyring_name_lock); } +} -} /* end keyring_publish_name() */ - -/*****************************************************************************/ /* - * initialise a keyring - * - we object if we were given any data + * Initialise a keyring. + * + * Returns 0 on success, -EINVAL if given any data. */ static int keyring_instantiate(struct key *keyring, - const void *data, size_t datalen) + struct key_preparsed_payload *prep) { int ret; ret = -EINVAL; - if (datalen == 0) { + if (prep->datalen == 0) { + assoc_array_init(&keyring->keys); /* make the keyring available by name if it has one */ keyring_publish_name(keyring); ret = 0; } return ret; +} -} /* end keyring_instantiate() */ +/* + * Multiply 64-bits by 32-bits to 96-bits and fold back to 64-bit. Ideally we'd + * fold the carry back too, but that requires inline asm. + */ +static u64 mult_64x32_and_fold(u64 x, u32 y) +{ + u64 hi = (u64)(u32)(x >> 32) * y; + u64 lo = (u64)(u32)(x) * y; + return lo + ((u64)(u32)hi << 32) + (u32)(hi >> 32); +} -/*****************************************************************************/ /* - * match keyrings on their name + * Hash a key type and description. */ -static int keyring_match(const struct key *keyring, const void *description) +static unsigned long hash_key_type_and_desc(const struct keyring_index_key *index_key) { - return keyring->description && - strcmp(keyring->description, description) == 0; + const unsigned level_shift = ASSOC_ARRAY_LEVEL_STEP; + const unsigned long fan_mask = ASSOC_ARRAY_FAN_MASK; + const char *description = index_key->description; + unsigned long hash, type; + u32 piece; + u64 acc; + int n, desc_len = index_key->desc_len; + + type = (unsigned long)index_key->type; + + acc = mult_64x32_and_fold(type, desc_len + 13); + acc = mult_64x32_and_fold(acc, 9207); + for (;;) { + n = desc_len; + if (n <= 0) + break; + if (n > 4) + n = 4; + piece = 0; + memcpy(&piece, description, n); + description += n; + desc_len -= n; + acc = mult_64x32_and_fold(acc, piece); + acc = mult_64x32_and_fold(acc, 9207); + } -} /* end keyring_match() */ + /* Fold the hash down to 32 bits if need be. */ + hash = acc; + if (ASSOC_ARRAY_KEY_CHUNK_SIZE == 32) + hash ^= acc >> 32; + + /* Squidge all the keyrings into a separate part of the tree to + * ordinary keys by making sure the lowest level segment in the hash is + * zero for keyrings and non-zero otherwise. + */ + if (index_key->type != &key_type_keyring && (hash & fan_mask) == 0) + return hash | (hash >> (ASSOC_ARRAY_KEY_CHUNK_SIZE - level_shift)) | 1; + if (index_key->type == &key_type_keyring && (hash & fan_mask) != 0) + return (hash + (hash << level_shift)) & ~fan_mask; + return hash; +} -/*****************************************************************************/ /* - * dispose of the data dangling from the corpse of a keyring + * Build the next index key chunk. + * + * On 32-bit systems the index key is laid out as: + * + * 0 4 5 9... + * hash desclen typeptr desc[] + * + * On 64-bit systems: + * + * 0 8 9 17... + * hash desclen typeptr desc[] + * + * We return it one word-sized chunk at a time. */ -static void keyring_destroy(struct key *keyring) +static unsigned long keyring_get_key_chunk(const void *data, int level) +{ + const struct keyring_index_key *index_key = data; + unsigned long chunk = 0; + long offset = 0; + int desc_len = index_key->desc_len, n = sizeof(chunk); + + level /= ASSOC_ARRAY_KEY_CHUNK_SIZE; + switch (level) { + case 0: + return hash_key_type_and_desc(index_key); + case 1: + return ((unsigned long)index_key->type << 8) | desc_len; + case 2: + if (desc_len == 0) + return (u8)((unsigned long)index_key->type >> + (ASSOC_ARRAY_KEY_CHUNK_SIZE - 8)); + n--; + offset = 1; + default: + offset += sizeof(chunk) - 1; + offset += (level - 3) * sizeof(chunk); + if (offset >= desc_len) + return 0; + desc_len -= offset; + if (desc_len > n) + desc_len = n; + offset += desc_len; + do { + chunk <<= 8; + chunk |= ((u8*)index_key->description)[--offset]; + } while (--desc_len > 0); + + if (level == 2) { + chunk <<= 8; + chunk |= (u8)((unsigned long)index_key->type >> + (ASSOC_ARRAY_KEY_CHUNK_SIZE - 8)); + } + return chunk; + } +} + +static unsigned long keyring_get_object_key_chunk(const void *object, int level) +{ + const struct key *key = keyring_ptr_to_key(object); + return keyring_get_key_chunk(&key->index_key, level); +} + +static bool keyring_compare_object(const void *object, const void *data) +{ + const struct keyring_index_key *index_key = data; + const struct key *key = keyring_ptr_to_key(object); + + return key->index_key.type == index_key->type && + key->index_key.desc_len == index_key->desc_len && + memcmp(key->index_key.description, index_key->description, + index_key->desc_len) == 0; +} + +/* + * Compare the index keys of a pair of objects and determine the bit position + * at which they differ - if they differ. + */ +static int keyring_diff_objects(const void *object, const void *data) +{ + const struct key *key_a = keyring_ptr_to_key(object); + const struct keyring_index_key *a = &key_a->index_key; + const struct keyring_index_key *b = data; + unsigned long seg_a, seg_b; + int level, i; + + level = 0; + seg_a = hash_key_type_and_desc(a); + seg_b = hash_key_type_and_desc(b); + if ((seg_a ^ seg_b) != 0) + goto differ; + + /* The number of bits contributed by the hash is controlled by a + * constant in the assoc_array headers. Everything else thereafter we + * can deal with as being machine word-size dependent. + */ + level += ASSOC_ARRAY_KEY_CHUNK_SIZE / 8; + seg_a = a->desc_len; + seg_b = b->desc_len; + if ((seg_a ^ seg_b) != 0) + goto differ; + + /* The next bit may not work on big endian */ + level++; + seg_a = (unsigned long)a->type; + seg_b = (unsigned long)b->type; + if ((seg_a ^ seg_b) != 0) + goto differ; + + level += sizeof(unsigned long); + if (a->desc_len == 0) + goto same; + + i = 0; + if (((unsigned long)a->description | (unsigned long)b->description) & + (sizeof(unsigned long) - 1)) { + do { + seg_a = *(unsigned long *)(a->description + i); + seg_b = *(unsigned long *)(b->description + i); + if ((seg_a ^ seg_b) != 0) + goto differ_plus_i; + i += sizeof(unsigned long); + } while (i < (a->desc_len & (sizeof(unsigned long) - 1))); + } + + for (; i < a->desc_len; i++) { + seg_a = *(unsigned char *)(a->description + i); + seg_b = *(unsigned char *)(b->description + i); + if ((seg_a ^ seg_b) != 0) + goto differ_plus_i; + } + +same: + return -1; + +differ_plus_i: + level += i; +differ: + i = level * 8 + __ffs(seg_a ^ seg_b); + return i; +} + +/* + * Free an object after stripping the keyring flag off of the pointer. + */ +static void keyring_free_object(void *object) { - struct keyring_list *klist; - int loop; + key_put(keyring_ptr_to_key(object)); +} + +/* + * Operations for keyring management by the index-tree routines. + */ +static const struct assoc_array_ops keyring_assoc_array_ops = { + .get_key_chunk = keyring_get_key_chunk, + .get_object_key_chunk = keyring_get_object_key_chunk, + .compare_object = keyring_compare_object, + .diff_objects = keyring_diff_objects, + .free_object = keyring_free_object, +}; +/* + * Clean up a keyring when it is destroyed. Unpublish its name if it had one + * and dispose of its data. + * + * The garbage collector detects the final key_put(), removes the keyring from + * the serial number tree and then does RCU synchronisation before coming here, + * so we shouldn't need to worry about code poking around here with the RCU + * readlock held by this time. + */ +static void keyring_destroy(struct key *keyring) +{ if (keyring->description) { write_lock(&keyring_name_lock); @@ -150,111 +383,110 @@ static void keyring_destroy(struct key *keyring) write_unlock(&keyring_name_lock); } - klist = rcu_dereference(keyring->payload.subscriptions); - if (klist) { - for (loop = klist->nkeys - 1; loop >= 0; loop--) - key_put(klist->keys[loop]); - kfree(klist); - } - -} /* end keyring_destroy() */ + assoc_array_destroy(&keyring->keys, &keyring_assoc_array_ops); +} -/*****************************************************************************/ /* - * describe the keyring + * Describe a keyring for /proc. */ static void keyring_describe(const struct key *keyring, struct seq_file *m) { - struct keyring_list *klist; - - if (keyring->description) { + if (keyring->description) seq_puts(m, keyring->description); - } - else { + else seq_puts(m, "[anon]"); + + if (key_is_instantiated(keyring)) { + if (keyring->keys.nr_leaves_on_tree != 0) + seq_printf(m, ": %lu", keyring->keys.nr_leaves_on_tree); + else + seq_puts(m, ": empty"); } +} - rcu_read_lock(); - klist = rcu_dereference(keyring->payload.subscriptions); - if (klist) - seq_printf(m, ": %u/%u", klist->nkeys, klist->maxkeys); - else - seq_puts(m, ": empty"); - rcu_read_unlock(); +struct keyring_read_iterator_context { + size_t qty; + size_t count; + key_serial_t __user *buffer; +}; + +static int keyring_read_iterator(const void *object, void *data) +{ + struct keyring_read_iterator_context *ctx = data; + const struct key *key = keyring_ptr_to_key(object); + int ret; + + kenter("{%s,%d},,{%zu/%zu}", + key->type->name, key->serial, ctx->count, ctx->qty); + + if (ctx->count >= ctx->qty) + return 1; -} /* end keyring_describe() */ + ret = put_user(key->serial, ctx->buffer); + if (ret < 0) + return ret; + ctx->buffer++; + ctx->count += sizeof(key->serial); + return 0; +} -/*****************************************************************************/ /* - * read a list of key IDs from the keyring's contents - * - the keyring's semaphore is read-locked + * Read a list of key IDs from the keyring's contents in binary form + * + * The keyring's semaphore is read-locked by the caller. This prevents someone + * from modifying it under us - which could cause us to read key IDs multiple + * times. */ static long keyring_read(const struct key *keyring, char __user *buffer, size_t buflen) { - struct keyring_list *klist; - struct key *key; - size_t qty, tmp; - int loop, ret; - - ret = 0; - klist = rcu_dereference(keyring->payload.subscriptions); + struct keyring_read_iterator_context ctx; + unsigned long nr_keys; + int ret; - if (klist) { - /* calculate how much data we could return */ - qty = klist->nkeys * sizeof(key_serial_t); + kenter("{%d},,%zu", key_serial(keyring), buflen); - if (buffer && buflen > 0) { - if (buflen > qty) - buflen = qty; + if (buflen & (sizeof(key_serial_t) - 1)) + return -EINVAL; - /* copy the IDs of the subscribed keys into the - * buffer */ - ret = -EFAULT; + nr_keys = keyring->keys.nr_leaves_on_tree; + if (nr_keys == 0) + return 0; - for (loop = 0; loop < klist->nkeys; loop++) { - key = klist->keys[loop]; + /* Calculate how much data we could return */ + ctx.qty = nr_keys * sizeof(key_serial_t); - tmp = sizeof(key_serial_t); - if (tmp > buflen) - tmp = buflen; + if (!buffer || !buflen) + return ctx.qty; - if (copy_to_user(buffer, - &key->serial, - tmp) != 0) - goto error; + if (buflen > ctx.qty) + ctx.qty = buflen; - buflen -= tmp; - if (buflen == 0) - break; - buffer += tmp; - } - } - - ret = qty; + /* Copy the IDs of the subscribed keys into the buffer */ + ctx.buffer = (key_serial_t __user *)buffer; + ctx.count = 0; + ret = assoc_array_iterate(&keyring->keys, keyring_read_iterator, &ctx); + if (ret < 0) { + kleave(" = %d [iterate]", ret); + return ret; } - error: - return ret; - -} /* end keyring_read() */ + kleave(" = %zu [ok]", ctx.count); + return ctx.count; +} -/*****************************************************************************/ /* - * allocate a keyring and link into the destination keyring + * Allocate a keyring and link into the destination keyring. */ -struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, - struct task_struct *ctx, unsigned long flags, - struct key *dest) +struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid, + const struct cred *cred, key_perm_t perm, + unsigned long flags, struct key *dest) { struct key *keyring; int ret; keyring = key_alloc(&key_type_keyring, description, - uid, gid, ctx, - (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL, - flags); - + uid, gid, cred, perm, flags); if (!IS_ERR(keyring)) { ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL); if (ret < 0) { @@ -264,242 +496,460 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid, } return keyring; +} +EXPORT_SYMBOL(keyring_alloc); -} /* end keyring_alloc() */ - -/*****************************************************************************/ /* - * search the supplied keyring tree for a key that matches the criterion - * - perform a breadth-then-depth search up to the prescribed limit - * - we only find keys on which we have search permission - * - we use the supplied match function to see if the description (or other - * feature of interest) matches - * - we rely on RCU to prevent the keyring lists from disappearing on us - * - we return -EAGAIN if we didn't find any matching key - * - we return -ENOKEY if we only found negative matching keys - * - we propagate the possession attribute from the keyring ref to the key ref + * Iteration function to consider each key found. */ -key_ref_t keyring_search_aux(key_ref_t keyring_ref, - struct task_struct *context, - struct key_type *type, - const void *description, - key_match_func_t match) +static int keyring_search_iterator(const void *object, void *iterator_data) { - struct { - struct keyring_list *keylist; - int kix; - } stack[KEYRING_SEARCH_MAX_DEPTH]; + struct keyring_search_context *ctx = iterator_data; + const struct key *key = keyring_ptr_to_key(object); + unsigned long kflags = key->flags; - struct keyring_list *keylist; - struct timespec now; - unsigned long possessed; - struct key *keyring, *key; - key_ref_t key_ref; - long err; - int sp, kix; + kenter("{%d}", key->serial); - keyring = key_ref_to_ptr(keyring_ref); - possessed = is_key_possessed(keyring_ref); - key_check(keyring); - - /* top keyring must have search permission to begin the search */ - err = key_task_permission(keyring_ref, context, KEY_SEARCH); - if (err < 0) { - key_ref = ERR_PTR(err); - goto error; + /* ignore keys not of this type */ + if (key->type != ctx->index_key.type) { + kleave(" = 0 [!type]"); + return 0; } - key_ref = ERR_PTR(-ENOTDIR); - if (keyring->type != &key_type_keyring) - goto error; + /* skip invalidated, revoked and expired keys */ + if (ctx->flags & KEYRING_SEARCH_DO_STATE_CHECK) { + if (kflags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) { + ctx->result = ERR_PTR(-EKEYREVOKED); + kleave(" = %d [invrev]", ctx->skipped_ret); + goto skipped; + } - rcu_read_lock(); + if (key->expiry && ctx->now.tv_sec >= key->expiry) { + ctx->result = ERR_PTR(-EKEYEXPIRED); + kleave(" = %d [expire]", ctx->skipped_ret); + goto skipped; + } + } - now = current_kernel_time(); - err = -EAGAIN; - sp = 0; + /* keys that don't match */ + if (!ctx->match(key, ctx->match_data)) { + kleave(" = 0 [!match]"); + return 0; + } - /* start processing a new keyring */ -descend: - if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) - goto not_this_keyring; + /* key must have search permissions */ + if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM) && + key_task_permission(make_key_ref(key, ctx->possessed), + ctx->cred, KEY_NEED_SEARCH) < 0) { + ctx->result = ERR_PTR(-EACCES); + kleave(" = %d [!perm]", ctx->skipped_ret); + goto skipped; + } - keylist = rcu_dereference(keyring->payload.subscriptions); - if (!keylist) - goto not_this_keyring; + if (ctx->flags & KEYRING_SEARCH_DO_STATE_CHECK) { + /* we set a different error code if we pass a negative key */ + if (kflags & (1 << KEY_FLAG_NEGATIVE)) { + smp_rmb(); + ctx->result = ERR_PTR(key->type_data.reject_error); + kleave(" = %d [neg]", ctx->skipped_ret); + goto skipped; + } + } - /* iterate through the keys in this keyring first */ - for (kix = 0; kix < keylist->nkeys; kix++) { - key = keylist->keys[kix]; + /* Found */ + ctx->result = make_key_ref(key, ctx->possessed); + kleave(" = 1 [found]"); + return 1; - /* ignore keys not of this type */ - if (key->type != type) - continue; +skipped: + return ctx->skipped_ret; +} - /* skip revoked keys and expired keys */ - if (test_bit(KEY_FLAG_REVOKED, &key->flags)) - continue; +/* + * Search inside a keyring for a key. We can search by walking to it + * directly based on its index-key or we can iterate over the entire + * tree looking for it, based on the match function. + */ +static int search_keyring(struct key *keyring, struct keyring_search_context *ctx) +{ + if ((ctx->flags & KEYRING_SEARCH_LOOKUP_TYPE) == + KEYRING_SEARCH_LOOKUP_DIRECT) { + const void *object; + + object = assoc_array_find(&keyring->keys, + &keyring_assoc_array_ops, + &ctx->index_key); + return object ? ctx->iterator(object, ctx) : 0; + } + return assoc_array_iterate(&keyring->keys, ctx->iterator, ctx); +} - if (key->expiry && now.tv_sec >= key->expiry) - continue; +/* + * Search a tree of keyrings that point to other keyrings up to the maximum + * depth. + */ +static bool search_nested_keyrings(struct key *keyring, + struct keyring_search_context *ctx) +{ + struct { + struct key *keyring; + struct assoc_array_node *node; + int slot; + } stack[KEYRING_SEARCH_MAX_DEPTH]; - /* keys that don't match */ - if (!match(key, description)) - continue; + struct assoc_array_shortcut *shortcut; + struct assoc_array_node *node; + struct assoc_array_ptr *ptr; + struct key *key; + int sp = 0, slot; + + kenter("{%d},{%s,%s}", + keyring->serial, + ctx->index_key.type->name, + ctx->index_key.description); + + if (ctx->index_key.description) + ctx->index_key.desc_len = strlen(ctx->index_key.description); + + /* Check to see if this top-level keyring is what we are looking for + * and whether it is valid or not. + */ + if (ctx->flags & KEYRING_SEARCH_LOOKUP_ITERATE || + keyring_compare_object(keyring, &ctx->index_key)) { + ctx->skipped_ret = 2; + ctx->flags |= KEYRING_SEARCH_DO_STATE_CHECK; + switch (ctx->iterator(keyring_key_to_ptr(keyring), ctx)) { + case 1: + goto found; + case 2: + return false; + default: + break; + } + } - /* key must have search permissions */ - if (key_task_permission(make_key_ref(key, possessed), - context, KEY_SEARCH) < 0) - continue; + ctx->skipped_ret = 0; + if (ctx->flags & KEYRING_SEARCH_NO_STATE_CHECK) + ctx->flags &= ~KEYRING_SEARCH_DO_STATE_CHECK; - /* we set a different error code if we find a negative key */ - if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) { - err = -ENOKEY; - continue; - } + /* Start processing a new keyring */ +descend_to_keyring: + kdebug("descend to %d", keyring->serial); + if (keyring->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) + goto not_this_keyring; + /* Search through the keys in this keyring before its searching its + * subtrees. + */ + if (search_keyring(keyring, ctx)) goto found; - } - /* search through the keyrings nested in this one */ - kix = 0; -ascend: - for (; kix < keylist->nkeys; kix++) { - key = keylist->keys[kix]; - if (key->type != &key_type_keyring) - continue; + /* Then manually iterate through the keyrings nested in this one. + * + * Start from the root node of the index tree. Because of the way the + * hash function has been set up, keyrings cluster on the leftmost + * branch of the root node (root slot 0) or in the root node itself. + * Non-keyrings avoid the leftmost branch of the root entirely (root + * slots 1-15). + */ + ptr = ACCESS_ONCE(keyring->keys.root); + if (!ptr) + goto not_this_keyring; - /* recursively search nested keyrings - * - only search keyrings for which we have search permission + if (assoc_array_ptr_is_shortcut(ptr)) { + /* If the root is a shortcut, either the keyring only contains + * keyring pointers (everything clusters behind root slot 0) or + * doesn't contain any keyring pointers. */ - if (sp >= KEYRING_SEARCH_MAX_DEPTH) + shortcut = assoc_array_ptr_to_shortcut(ptr); + smp_read_barrier_depends(); + if ((shortcut->index_key[0] & ASSOC_ARRAY_FAN_MASK) != 0) + goto not_this_keyring; + + ptr = ACCESS_ONCE(shortcut->next_node); + node = assoc_array_ptr_to_node(ptr); + goto begin_node; + } + + node = assoc_array_ptr_to_node(ptr); + smp_read_barrier_depends(); + + ptr = node->slots[0]; + if (!assoc_array_ptr_is_meta(ptr)) + goto begin_node; + +descend_to_node: + /* Descend to a more distal node in this keyring's content tree and go + * through that. + */ + kdebug("descend"); + if (assoc_array_ptr_is_shortcut(ptr)) { + shortcut = assoc_array_ptr_to_shortcut(ptr); + smp_read_barrier_depends(); + ptr = ACCESS_ONCE(shortcut->next_node); + BUG_ON(!assoc_array_ptr_is_node(ptr)); + } + node = assoc_array_ptr_to_node(ptr); + +begin_node: + kdebug("begin_node"); + smp_read_barrier_depends(); + slot = 0; +ascend_to_node: + /* Go through the slots in a node */ + for (; slot < ASSOC_ARRAY_FAN_OUT; slot++) { + ptr = ACCESS_ONCE(node->slots[slot]); + + if (assoc_array_ptr_is_meta(ptr) && node->back_pointer) + goto descend_to_node; + + if (!keyring_ptr_is_keyring(ptr)) continue; - if (key_task_permission(make_key_ref(key, possessed), - context, KEY_SEARCH) < 0) + key = keyring_ptr_to_key(ptr); + + if (sp >= KEYRING_SEARCH_MAX_DEPTH) { + if (ctx->flags & KEYRING_SEARCH_DETECT_TOO_DEEP) { + ctx->result = ERR_PTR(-ELOOP); + return false; + } + goto not_this_keyring; + } + + /* Search a nested keyring */ + if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM) && + key_task_permission(make_key_ref(key, ctx->possessed), + ctx->cred, KEY_NEED_SEARCH) < 0) continue; /* stack the current position */ - stack[sp].keylist = keylist; - stack[sp].kix = kix; + stack[sp].keyring = keyring; + stack[sp].node = node; + stack[sp].slot = slot; sp++; /* begin again with the new keyring */ keyring = key; - goto descend; + goto descend_to_keyring; } - /* the keyring we're looking at was disqualified or didn't contain a - * matching key */ + /* We've dealt with all the slots in the current node, so now we need + * to ascend to the parent and continue processing there. + */ + ptr = ACCESS_ONCE(node->back_pointer); + slot = node->parent_slot; + + if (ptr && assoc_array_ptr_is_shortcut(ptr)) { + shortcut = assoc_array_ptr_to_shortcut(ptr); + smp_read_barrier_depends(); + ptr = ACCESS_ONCE(shortcut->back_pointer); + slot = shortcut->parent_slot; + } + if (!ptr) + goto not_this_keyring; + node = assoc_array_ptr_to_node(ptr); + smp_read_barrier_depends(); + slot++; + + /* If we've ascended to the root (zero backpointer), we must have just + * finished processing the leftmost branch rather than the root slots - + * so there can't be any more keyrings for us to find. + */ + if (node->back_pointer) { + kdebug("ascend %d", slot); + goto ascend_to_node; + } + + /* The keyring we're looking at was disqualified or didn't contain a + * matching key. + */ not_this_keyring: - if (sp > 0) { - /* resume the processing of a keyring higher up in the tree */ - sp--; - keylist = stack[sp].keylist; - kix = stack[sp].kix + 1; - goto ascend; + kdebug("not_this_keyring %d", sp); + if (sp <= 0) { + kleave(" = false"); + return false; } - key_ref = ERR_PTR(err); - goto error_2; + /* Resume the processing of a keyring higher up in the tree */ + sp--; + keyring = stack[sp].keyring; + node = stack[sp].node; + slot = stack[sp].slot + 1; + kdebug("ascend to %d [%d]", keyring->serial, slot); + goto ascend_to_node; - /* we found a viable match */ + /* We found a viable match */ found: - atomic_inc(&key->usage); + key = key_ref_to_ptr(ctx->result); key_check(key); - key_ref = make_key_ref(key, possessed); -error_2: - rcu_read_unlock(); -error: - return key_ref; + if (!(ctx->flags & KEYRING_SEARCH_NO_UPDATE_TIME)) { + key->last_used_at = ctx->now.tv_sec; + keyring->last_used_at = ctx->now.tv_sec; + while (sp > 0) + stack[--sp].keyring->last_used_at = ctx->now.tv_sec; + } + kleave(" = true"); + return true; +} + +/** + * keyring_search_aux - Search a keyring tree for a key matching some criteria + * @keyring_ref: A pointer to the keyring with possession indicator. + * @ctx: The keyring search context. + * + * Search the supplied keyring tree for a key that matches the criteria given. + * The root keyring and any linked keyrings must grant Search permission to the + * caller to be searchable and keys can only be found if they too grant Search + * to the caller. The possession flag on the root keyring pointer controls use + * of the possessor bits in permissions checking of the entire tree. In + * addition, the LSM gets to forbid keyring searches and key matches. + * + * The search is performed as a breadth-then-depth search up to the prescribed + * limit (KEYRING_SEARCH_MAX_DEPTH). + * + * Keys are matched to the type provided and are then filtered by the match + * function, which is given the description to use in any way it sees fit. The + * match function may use any attributes of a key that it wishes to to + * determine the match. Normally the match function from the key type would be + * used. + * + * RCU can be used to prevent the keyring key lists from disappearing without + * the need to take lots of locks. + * + * Returns a pointer to the found key and increments the key usage count if + * successful; -EAGAIN if no matching keys were found, or if expired or revoked + * keys were found; -ENOKEY if only negative keys were found; -ENOTDIR if the + * specified keyring wasn't a keyring. + * + * In the case of a successful return, the possession attribute from + * @keyring_ref is propagated to the returned key reference. + */ +key_ref_t keyring_search_aux(key_ref_t keyring_ref, + struct keyring_search_context *ctx) +{ + struct key *keyring; + long err; -} /* end keyring_search_aux() */ + ctx->iterator = keyring_search_iterator; + ctx->possessed = is_key_possessed(keyring_ref); + ctx->result = ERR_PTR(-EAGAIN); -/*****************************************************************************/ -/* - * search the supplied keyring tree for a key that matches the criterion - * - perform a breadth-then-depth search up to the prescribed limit - * - we only find keys on which we have search permission - * - we readlock the keyrings as we search down the tree - * - we return -EAGAIN if we didn't find any matching key - * - we return -ENOKEY if we only found negative matching keys + keyring = key_ref_to_ptr(keyring_ref); + key_check(keyring); + + if (keyring->type != &key_type_keyring) + return ERR_PTR(-ENOTDIR); + + if (!(ctx->flags & KEYRING_SEARCH_NO_CHECK_PERM)) { + err = key_task_permission(keyring_ref, ctx->cred, KEY_NEED_SEARCH); + if (err < 0) + return ERR_PTR(err); + } + + rcu_read_lock(); + ctx->now = current_kernel_time(); + if (search_nested_keyrings(keyring, ctx)) + __key_get(key_ref_to_ptr(ctx->result)); + rcu_read_unlock(); + return ctx->result; +} + +/** + * keyring_search - Search the supplied keyring tree for a matching key + * @keyring: The root of the keyring tree to be searched. + * @type: The type of keyring we want to find. + * @description: The name of the keyring we want to find. + * + * As keyring_search_aux() above, but using the current task's credentials and + * type's default matching function and preferred search method. */ key_ref_t keyring_search(key_ref_t keyring, struct key_type *type, const char *description) { - if (!type->match) + struct keyring_search_context ctx = { + .index_key.type = type, + .index_key.description = description, + .cred = current_cred(), + .match = type->match, + .match_data = description, + .flags = (type->def_lookup_type | + KEYRING_SEARCH_DO_STATE_CHECK), + }; + + if (!ctx.match) return ERR_PTR(-ENOKEY); - return keyring_search_aux(keyring, current, - type, description, type->match); - -} /* end keyring_search() */ - + return keyring_search_aux(keyring, &ctx); +} EXPORT_SYMBOL(keyring_search); -/*****************************************************************************/ /* - * search the given keyring only (no recursion) - * - keyring must be locked by caller - * - caller must guarantee that the keyring is a keyring + * Search the given keyring for a key that might be updated. + * + * The caller must guarantee that the keyring is a keyring and that the + * permission is granted to modify the keyring as no check is made here. The + * caller must also hold a lock on the keyring semaphore. + * + * Returns a pointer to the found key with usage count incremented if + * successful and returns NULL if not found. Revoked and invalidated keys are + * skipped over. + * + * If successful, the possession indicator is propagated from the keyring ref + * to the returned key reference. */ -key_ref_t __keyring_search_one(key_ref_t keyring_ref, - const struct key_type *ktype, - const char *description, - key_perm_t perm) +key_ref_t find_key_to_update(key_ref_t keyring_ref, + const struct keyring_index_key *index_key) { - struct keyring_list *klist; - unsigned long possessed; struct key *keyring, *key; - int loop; + const void *object; keyring = key_ref_to_ptr(keyring_ref); - possessed = is_key_possessed(keyring_ref); - rcu_read_lock(); + kenter("{%d},{%s,%s}", + keyring->serial, index_key->type->name, index_key->description); - klist = rcu_dereference(keyring->payload.subscriptions); - if (klist) { - for (loop = 0; loop < klist->nkeys; loop++) { - key = klist->keys[loop]; - - if (key->type == ktype && - (!key->type->match || - key->type->match(key, description)) && - key_permission(make_key_ref(key, possessed), - perm) == 0 && - !test_bit(KEY_FLAG_REVOKED, &key->flags) - ) - goto found; - } - } + object = assoc_array_find(&keyring->keys, &keyring_assoc_array_ops, + index_key); - rcu_read_unlock(); - return ERR_PTR(-ENOKEY); + if (object) + goto found; - found: - atomic_inc(&key->usage); - rcu_read_unlock(); - return make_key_ref(key, possessed); + kleave(" = NULL"); + return NULL; -} /* end __keyring_search_one() */ +found: + key = keyring_ptr_to_key(object); + if (key->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) { + kleave(" = NULL [x]"); + return NULL; + } + __key_get(key); + kleave(" = {%d}", key->serial); + return make_key_ref(key, is_key_possessed(keyring_ref)); +} -/*****************************************************************************/ /* - * find a keyring with the specified name - * - all named keyrings are searched - * - only find keyrings with search permission for the process - * - only find keyrings with a serial number greater than the one specified + * Find a keyring with the specified name. + * + * All named keyrings in the current user namespace are searched, provided they + * grant Search permission directly to the caller (unless this check is + * skipped). Keyrings whose usage points have reached zero or who have been + * revoked are skipped. + * + * Returns a pointer to the keyring with the keyring's refcount having being + * incremented on success. -ENOKEY is returned if a key could not be found. */ -struct key *find_keyring_by_name(const char *name, key_serial_t bound) +struct key *find_keyring_by_name(const char *name, bool skip_perm_check) { struct key *keyring; int bucket; - keyring = ERR_PTR(-EINVAL); if (!name) - goto error; + return ERR_PTR(-EINVAL); bucket = keyring_hash(name); @@ -512,465 +962,403 @@ struct key *find_keyring_by_name(const char *name, key_serial_t bound) &keyring_name_hash[bucket], type_data.link ) { + if (!kuid_has_mapping(current_user_ns(), keyring->user->uid)) + continue; + if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) continue; if (strcmp(keyring->description, name) != 0) continue; - if (key_permission(make_key_ref(keyring, 0), - KEY_SEARCH) < 0) + if (!skip_perm_check && + key_permission(make_key_ref(keyring, 0), + KEY_NEED_SEARCH) < 0) continue; - /* found a potential candidate, but we still need to - * check the serial number */ - if (keyring->serial <= bound) + /* we've got a match but we might end up racing with + * key_cleanup() if the keyring is currently 'dead' + * (ie. it has a zero usage count) */ + if (!atomic_inc_not_zero(&keyring->usage)) continue; - - /* we've got a match */ - atomic_inc(&keyring->usage); - read_unlock(&keyring_name_lock); - goto error; + keyring->last_used_at = current_kernel_time().tv_sec; + goto out; } } - read_unlock(&keyring_name_lock); keyring = ERR_PTR(-ENOKEY); - - error: +out: + read_unlock(&keyring_name_lock); return keyring; +} + +static int keyring_detect_cycle_iterator(const void *object, + void *iterator_data) +{ + struct keyring_search_context *ctx = iterator_data; + const struct key *key = keyring_ptr_to_key(object); + + kenter("{%d}", key->serial); + + /* We might get a keyring with matching index-key that is nonetheless a + * different keyring. */ + if (key != ctx->match_data) + return 0; -} /* end find_keyring_by_name() */ + ctx->result = ERR_PTR(-EDEADLK); + return 1; +} -/*****************************************************************************/ /* - * see if a cycle will will be created by inserting acyclic tree B in acyclic - * tree A at the topmost level (ie: as a direct child of A) - * - since we are adding B to A at the top level, checking for cycles should - * just be a matter of seeing if node A is somewhere in tree B + * See if a cycle will will be created by inserting acyclic tree B in acyclic + * tree A at the topmost level (ie: as a direct child of A). + * + * Since we are adding B to A at the top level, checking for cycles should just + * be a matter of seeing if node A is somewhere in tree B. */ static int keyring_detect_cycle(struct key *A, struct key *B) { - struct { - struct keyring_list *keylist; - int kix; - } stack[KEYRING_SEARCH_MAX_DEPTH]; - - struct keyring_list *keylist; - struct key *subtree, *key; - int sp, kix, ret; + struct keyring_search_context ctx = { + .index_key = A->index_key, + .match_data = A, + .iterator = keyring_detect_cycle_iterator, + .flags = (KEYRING_SEARCH_LOOKUP_DIRECT | + KEYRING_SEARCH_NO_STATE_CHECK | + KEYRING_SEARCH_NO_UPDATE_TIME | + KEYRING_SEARCH_NO_CHECK_PERM | + KEYRING_SEARCH_DETECT_TOO_DEEP), + }; rcu_read_lock(); + search_nested_keyrings(B, &ctx); + rcu_read_unlock(); + return PTR_ERR(ctx.result) == -EAGAIN ? 0 : PTR_ERR(ctx.result); +} - ret = -EDEADLK; - if (A == B) - goto cycle_detected; - - subtree = B; - sp = 0; - - /* start processing a new keyring */ - descend: - if (test_bit(KEY_FLAG_REVOKED, &subtree->flags)) - goto not_this_keyring; - - keylist = rcu_dereference(subtree->payload.subscriptions); - if (!keylist) - goto not_this_keyring; - kix = 0; +/* + * Preallocate memory so that a key can be linked into to a keyring. + */ +int __key_link_begin(struct key *keyring, + const struct keyring_index_key *index_key, + struct assoc_array_edit **_edit) + __acquires(&keyring->sem) + __acquires(&keyring_serialise_link_sem) +{ + struct assoc_array_edit *edit; + int ret; - ascend: - /* iterate through the remaining keys in this keyring */ - for (; kix < keylist->nkeys; kix++) { - key = keylist->keys[kix]; + kenter("%d,%s,%s,", + keyring->serial, index_key->type->name, index_key->description); - if (key == A) - goto cycle_detected; + BUG_ON(index_key->desc_len == 0); - /* recursively check nested keyrings */ - if (key->type == &key_type_keyring) { - if (sp >= KEYRING_SEARCH_MAX_DEPTH) - goto too_deep; + if (keyring->type != &key_type_keyring) + return -ENOTDIR; - /* stack the current position */ - stack[sp].keylist = keylist; - stack[sp].kix = kix; - sp++; + down_write(&keyring->sem); - /* begin again with the new keyring */ - subtree = key; - goto descend; - } + ret = -EKEYREVOKED; + if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) + goto error_krsem; + + /* serialise link/link calls to prevent parallel calls causing a cycle + * when linking two keyring in opposite orders */ + if (index_key->type == &key_type_keyring) + down_write(&keyring_serialise_link_sem); + + /* Create an edit script that will insert/replace the key in the + * keyring tree. + */ + edit = assoc_array_insert(&keyring->keys, + &keyring_assoc_array_ops, + index_key, + NULL); + if (IS_ERR(edit)) { + ret = PTR_ERR(edit); + goto error_sem; } - /* the keyring we're looking at was disqualified or didn't contain a - * matching key */ - not_this_keyring: - if (sp > 0) { - /* resume the checking of a keyring higher up in the tree */ - sp--; - keylist = stack[sp].keylist; - kix = stack[sp].kix + 1; - goto ascend; + /* If we're not replacing a link in-place then we're going to need some + * extra quota. + */ + if (!edit->dead_leaf) { + ret = key_payload_reserve(keyring, + keyring->datalen + KEYQUOTA_LINK_BYTES); + if (ret < 0) + goto error_cancel; } - ret = 0; /* no cycles detected */ + *_edit = edit; + kleave(" = 0"); + return 0; - error: - rcu_read_unlock(); +error_cancel: + assoc_array_cancel_edit(edit); +error_sem: + if (index_key->type == &key_type_keyring) + up_write(&keyring_serialise_link_sem); +error_krsem: + up_write(&keyring->sem); + kleave(" = %d", ret); return ret; +} - too_deep: - ret = -ELOOP; - goto error; - - cycle_detected: - ret = -EDEADLK; - goto error; - -} /* end keyring_detect_cycle() */ - -/*****************************************************************************/ /* - * dispose of a keyring list after the RCU grace period + * Check already instantiated keys aren't going to be a problem. + * + * The caller must have called __key_link_begin(). Don't need to call this for + * keys that were created since __key_link_begin() was called. */ -static void keyring_link_rcu_disposal(struct rcu_head *rcu) +int __key_link_check_live_key(struct key *keyring, struct key *key) { - struct keyring_list *klist = - container_of(rcu, struct keyring_list, rcu); - - kfree(klist); - -} /* end keyring_link_rcu_disposal() */ + if (key->type == &key_type_keyring) + /* check that we aren't going to create a cycle by linking one + * keyring to another */ + return keyring_detect_cycle(keyring, key); + return 0; +} -/*****************************************************************************/ /* - * dispose of a keyring list after the RCU grace period, freeing the unlinked - * key + * Link a key into to a keyring. + * + * Must be called with __key_link_begin() having being called. Discards any + * already extant link to matching key if there is one, so that each keyring + * holds at most one link to any given key of a particular type+description + * combination. */ -static void keyring_unlink_rcu_disposal(struct rcu_head *rcu) +void __key_link(struct key *key, struct assoc_array_edit **_edit) { - struct keyring_list *klist = - container_of(rcu, struct keyring_list, rcu); - - key_put(klist->keys[klist->delkey]); - kfree(klist); - -} /* end keyring_unlink_rcu_disposal() */ + __key_get(key); + assoc_array_insert_set_object(*_edit, keyring_key_to_ptr(key)); + assoc_array_apply_edit(*_edit); + *_edit = NULL; +} -/*****************************************************************************/ /* - * link a key into to a keyring - * - must be called with the keyring's semaphore write-locked - * - discard already extant link to matching key if there is one + * Finish linking a key into to a keyring. + * + * Must be called with __key_link_begin() having being called. */ -int __key_link(struct key *keyring, struct key *key) +void __key_link_end(struct key *keyring, + const struct keyring_index_key *index_key, + struct assoc_array_edit *edit) + __releases(&keyring->sem) + __releases(&keyring_serialise_link_sem) { - struct keyring_list *klist, *nklist; - unsigned max; - size_t size; - int loop, ret; - - ret = -EKEYREVOKED; - if (test_bit(KEY_FLAG_REVOKED, &keyring->flags)) - goto error; - - ret = -ENOTDIR; - if (keyring->type != &key_type_keyring) - goto error; - - /* serialise link/link calls to prevent parallel calls causing a - * cycle when applied to two keyring in opposite orders */ - down_write(&keyring_serialise_link_sem); + BUG_ON(index_key->type == NULL); + kenter("%d,%s,", keyring->serial, index_key->type->name); - /* check that we aren't going to create a cycle adding one keyring to - * another */ - if (key->type == &key_type_keyring) { - ret = keyring_detect_cycle(keyring, key); - if (ret < 0) - goto error2; - } - - /* see if there's a matching key we can displace */ - klist = keyring->payload.subscriptions; - - if (klist && klist->nkeys > 0) { - struct key_type *type = key->type; - - for (loop = klist->nkeys - 1; loop >= 0; loop--) { - if (klist->keys[loop]->type == type && - strcmp(klist->keys[loop]->description, - key->description) == 0 - ) { - /* found a match - replace with new key */ - size = sizeof(struct key *) * klist->maxkeys; - size += sizeof(*klist); - BUG_ON(size > PAGE_SIZE); - - ret = -ENOMEM; - nklist = kmemdup(klist, size, GFP_KERNEL); - if (!nklist) - goto error2; + if (index_key->type == &key_type_keyring) + up_write(&keyring_serialise_link_sem); - /* replace matched key */ - atomic_inc(&key->usage); - nklist->keys[loop] = key; - - rcu_assign_pointer( - keyring->payload.subscriptions, - nklist); - - /* dispose of the old keyring list and the - * displaced key */ - klist->delkey = loop; - call_rcu(&klist->rcu, - keyring_unlink_rcu_disposal); - - goto done; - } - } + if (edit && !edit->dead_leaf) { + key_payload_reserve(keyring, + keyring->datalen - KEYQUOTA_LINK_BYTES); + assoc_array_cancel_edit(edit); } + up_write(&keyring->sem); +} - /* check that we aren't going to overrun the user's quota */ - ret = key_payload_reserve(keyring, - keyring->datalen + KEYQUOTA_LINK_BYTES); - if (ret < 0) - goto error2; - - klist = keyring->payload.subscriptions; - - if (klist && klist->nkeys < klist->maxkeys) { - /* there's sufficient slack space to add directly */ - atomic_inc(&key->usage); - - klist->keys[klist->nkeys] = key; - smp_wmb(); - klist->nkeys++; - smp_wmb(); - } - else { - /* grow the key list */ - max = 4; - if (klist) - max += klist->maxkeys; - - ret = -ENFILE; - if (max > 65535) - goto error3; - size = sizeof(*klist) + sizeof(struct key *) * max; - if (size > PAGE_SIZE) - goto error3; - - ret = -ENOMEM; - nklist = kmalloc(size, GFP_KERNEL); - if (!nklist) - goto error3; - nklist->maxkeys = max; - nklist->nkeys = 0; - - if (klist) { - nklist->nkeys = klist->nkeys; - memcpy(nklist->keys, - klist->keys, - sizeof(struct key *) * klist->nkeys); - } - - /* add the key into the new space */ - atomic_inc(&key->usage); - nklist->keys[nklist->nkeys++] = key; - - rcu_assign_pointer(keyring->payload.subscriptions, nklist); - - /* dispose of the old keyring list */ - if (klist) - call_rcu(&klist->rcu, keyring_link_rcu_disposal); - } - -done: - ret = 0; -error2: - up_write(&keyring_serialise_link_sem); -error: - return ret; - -error3: - /* undo the quota changes */ - key_payload_reserve(keyring, - keyring->datalen - KEYQUOTA_LINK_BYTES); - goto error2; - -} /* end __key_link() */ - -/*****************************************************************************/ -/* - * link a key to a keyring +/** + * key_link - Link a key to a keyring + * @keyring: The keyring to make the link in. + * @key: The key to link to. + * + * Make a link in a keyring to a key, such that the keyring holds a reference + * on that key and the key can potentially be found by searching that keyring. + * + * This function will write-lock the keyring's semaphore and will consume some + * of the user's key data quota to hold the link. + * + * Returns 0 if successful, -ENOTDIR if the keyring isn't a keyring, + * -EKEYREVOKED if the keyring has been revoked, -ENFILE if the keyring is + * full, -EDQUOT if there is insufficient key data quota remaining to add + * another link or -ENOMEM if there's insufficient memory. + * + * It is assumed that the caller has checked that it is permitted for a link to + * be made (the keyring should have Write permission and the key Link + * permission). */ int key_link(struct key *keyring, struct key *key) { + struct assoc_array_edit *edit; int ret; + kenter("{%d,%d}", keyring->serial, atomic_read(&keyring->usage)); + key_check(keyring); key_check(key); - down_write(&keyring->sem); - ret = __key_link(keyring, key); - up_write(&keyring->sem); + if (test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags) && + !test_bit(KEY_FLAG_TRUSTED, &key->flags)) + return -EPERM; + + ret = __key_link_begin(keyring, &key->index_key, &edit); + if (ret == 0) { + kdebug("begun {%d,%d}", keyring->serial, atomic_read(&keyring->usage)); + ret = __key_link_check_live_key(keyring, key); + if (ret == 0) + __key_link(key, &edit); + __key_link_end(keyring, &key->index_key, edit); + } + kleave(" = %d {%d,%d}", ret, keyring->serial, atomic_read(&keyring->usage)); return ret; - -} /* end key_link() */ - +} EXPORT_SYMBOL(key_link); -/*****************************************************************************/ -/* - * unlink the first link to a key from a keyring +/** + * key_unlink - Unlink the first link to a key from a keyring. + * @keyring: The keyring to remove the link from. + * @key: The key the link is to. + * + * Remove a link from a keyring to a key. + * + * This function will write-lock the keyring's semaphore. + * + * Returns 0 if successful, -ENOTDIR if the keyring isn't a keyring, -ENOENT if + * the key isn't linked to by the keyring or -ENOMEM if there's insufficient + * memory. + * + * It is assumed that the caller has checked that it is permitted for a link to + * be removed (the keyring should have Write permission; no permissions are + * required on the key). */ int key_unlink(struct key *keyring, struct key *key) { - struct keyring_list *klist, *nklist; - int loop, ret; + struct assoc_array_edit *edit; + int ret; key_check(keyring); key_check(key); - ret = -ENOTDIR; if (keyring->type != &key_type_keyring) - goto error; + return -ENOTDIR; down_write(&keyring->sem); - klist = keyring->payload.subscriptions; - if (klist) { - /* search the keyring for the key */ - for (loop = 0; loop < klist->nkeys; loop++) - if (klist->keys[loop] == key) - goto key_is_present; + edit = assoc_array_delete(&keyring->keys, &keyring_assoc_array_ops, + &key->index_key); + if (IS_ERR(edit)) { + ret = PTR_ERR(edit); + goto error; } - - up_write(&keyring->sem); ret = -ENOENT; - goto error; - -key_is_present: - /* we need to copy the key list for RCU purposes */ - nklist = kmalloc(sizeof(*klist) + - sizeof(struct key *) * klist->maxkeys, - GFP_KERNEL); - if (!nklist) - goto nomem; - nklist->maxkeys = klist->maxkeys; - nklist->nkeys = klist->nkeys - 1; - - if (loop > 0) - memcpy(&nklist->keys[0], - &klist->keys[0], - loop * sizeof(struct key *)); - - if (loop < nklist->nkeys) - memcpy(&nklist->keys[loop], - &klist->keys[loop + 1], - (nklist->nkeys - loop) * sizeof(struct key *)); - - /* adjust the user's quota */ - key_payload_reserve(keyring, - keyring->datalen - KEYQUOTA_LINK_BYTES); - - rcu_assign_pointer(keyring->payload.subscriptions, nklist); - - up_write(&keyring->sem); - - /* schedule for later cleanup */ - klist->delkey = loop; - call_rcu(&klist->rcu, keyring_unlink_rcu_disposal); + if (edit == NULL) + goto error; + assoc_array_apply_edit(edit); + key_payload_reserve(keyring, keyring->datalen - KEYQUOTA_LINK_BYTES); ret = 0; error: - return ret; -nomem: - ret = -ENOMEM; up_write(&keyring->sem); - goto error; - -} /* end key_unlink() */ - + return ret; +} EXPORT_SYMBOL(key_unlink); -/*****************************************************************************/ -/* - * dispose of a keyring list after the RCU grace period, releasing the keys it - * links to +/** + * keyring_clear - Clear a keyring + * @keyring: The keyring to clear. + * + * Clear the contents of the specified keyring. + * + * Returns 0 if successful or -ENOTDIR if the keyring isn't a keyring. */ -static void keyring_clear_rcu_disposal(struct rcu_head *rcu) +int keyring_clear(struct key *keyring) { - struct keyring_list *klist; - int loop; + struct assoc_array_edit *edit; + int ret; - klist = container_of(rcu, struct keyring_list, rcu); + if (keyring->type != &key_type_keyring) + return -ENOTDIR; - for (loop = klist->nkeys - 1; loop >= 0; loop--) - key_put(klist->keys[loop]); + down_write(&keyring->sem); - kfree(klist); + edit = assoc_array_clear(&keyring->keys, &keyring_assoc_array_ops); + if (IS_ERR(edit)) { + ret = PTR_ERR(edit); + } else { + if (edit) + assoc_array_apply_edit(edit); + key_payload_reserve(keyring, 0); + ret = 0; + } -} /* end keyring_clear_rcu_disposal() */ + up_write(&keyring->sem); + return ret; +} +EXPORT_SYMBOL(keyring_clear); -/*****************************************************************************/ /* - * clear the specified process keyring - * - implements keyctl(KEYCTL_CLEAR) + * Dispose of the links from a revoked keyring. + * + * This is called with the key sem write-locked. */ -int keyring_clear(struct key *keyring) +static void keyring_revoke(struct key *keyring) { - struct keyring_list *klist; - int ret; - - ret = -ENOTDIR; - if (keyring->type == &key_type_keyring) { - /* detach the pointer block with the locks held */ - down_write(&keyring->sem); - - klist = keyring->payload.subscriptions; - if (klist) { - /* adjust the quota */ - key_payload_reserve(keyring, - sizeof(struct keyring_list)); - - rcu_assign_pointer(keyring->payload.subscriptions, - NULL); - } + struct assoc_array_edit *edit; - up_write(&keyring->sem); - - /* free the keys after the locks have been dropped */ - if (klist) - call_rcu(&klist->rcu, keyring_clear_rcu_disposal); - - ret = 0; + edit = assoc_array_clear(&keyring->keys, &keyring_assoc_array_ops); + if (!IS_ERR(edit)) { + if (edit) + assoc_array_apply_edit(edit); + key_payload_reserve(keyring, 0); } +} - return ret; +static bool keyring_gc_select_iterator(void *object, void *iterator_data) +{ + struct key *key = keyring_ptr_to_key(object); + time_t *limit = iterator_data; -} /* end keyring_clear() */ + if (key_is_dead(key, *limit)) + return false; + key_get(key); + return true; +} -EXPORT_SYMBOL(keyring_clear); +static int keyring_gc_check_iterator(const void *object, void *iterator_data) +{ + const struct key *key = keyring_ptr_to_key(object); + time_t *limit = iterator_data; + + key_check(key); + return key_is_dead(key, *limit); +} -/*****************************************************************************/ /* - * dispose of the links from a revoked keyring - * - called with the key sem write-locked + * Garbage collect pointers from a keyring. + * + * Not called with any locks held. The keyring's key struct will not be + * deallocated under us as only our caller may deallocate it. */ -static void keyring_revoke(struct key *keyring) +void keyring_gc(struct key *keyring, time_t limit) { - struct keyring_list *klist = keyring->payload.subscriptions; + int result; - /* adjust the quota */ - key_payload_reserve(keyring, 0); + kenter("%x{%s}", keyring->serial, keyring->description ?: ""); - if (klist) { - rcu_assign_pointer(keyring->payload.subscriptions, NULL); - call_rcu(&klist->rcu, keyring_clear_rcu_disposal); - } + if (keyring->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED))) + goto dont_gc; -} /* end keyring_revoke() */ + /* scan the keyring looking for dead keys */ + rcu_read_lock(); + result = assoc_array_iterate(&keyring->keys, + keyring_gc_check_iterator, &limit); + rcu_read_unlock(); + if (result == true) + goto do_gc; + +dont_gc: + kleave(" [no gc]"); + return; + +do_gc: + down_write(&keyring->sem); + assoc_array_gc(&keyring->keys, &keyring_assoc_array_ops, + keyring_gc_select_iterator, &limit); + up_write(&keyring->sem); + kleave(" [gc]"); +} diff --git a/security/keys/permission.c b/security/keys/permission.c index 3b41f9b5253..732cc0beffd 100644 --- a/security/keys/permission.c +++ b/security/keys/permission.c @@ -1,4 +1,4 @@ -/* permission.c: key permission determination +/* Key permission checking * * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) @@ -13,14 +13,22 @@ #include <linux/security.h> #include "internal.h" -/*****************************************************************************/ -/* - * check to see whether permission is granted to use a key in the desired way, - * but permit the security modules to override +/** + * key_task_permission - Check a key can be used + * @key_ref: The key to check. + * @cred: The credentials to use. + * @perm: The permissions to check for. + * + * Check to see whether permission is granted to use a key in the desired way, + * but permit the security modules to override. + * + * The caller must hold either a ref on cred or must hold the RCU readlock. + * + * Returns 0 if successful, -EACCES if access is denied based on the + * permissions bits or the LSM check. */ -int key_task_permission(const key_ref_t key_ref, - struct task_struct *context, - key_perm_t perm) +int key_task_permission(const key_ref_t key_ref, const struct cred *cred, + unsigned perm) { struct key *key; key_perm_t kperm; @@ -29,23 +37,20 @@ int key_task_permission(const key_ref_t key_ref, key = key_ref_to_ptr(key_ref); /* use the second 8-bits of permissions for keys the caller owns */ - if (key->uid == context->fsuid) { + if (uid_eq(key->uid, cred->fsuid)) { kperm = key->perm >> 16; goto use_these_perms; } /* use the third 8-bits of permissions for keys the caller has a group * membership in common with */ - if (key->gid != -1 && key->perm & KEY_GRP_ALL) { - if (key->gid == context->fsgid) { + if (gid_valid(key->gid) && key->perm & KEY_GRP_ALL) { + if (gid_eq(key->gid, cred->fsgid)) { kperm = key->perm >> 8; goto use_these_perms; } - task_lock(context); - ret = groups_search(context->group_info, key->gid); - task_unlock(context); - + ret = groups_search(cred->group_info, key->gid); if (ret) { kperm = key->perm >> 8; goto use_these_perms; @@ -56,52 +61,50 @@ int key_task_permission(const key_ref_t key_ref, kperm = key->perm; use_these_perms: + /* use the top 8-bits of permissions for keys the caller possesses * - possessor permissions are additive with other permissions */ if (is_key_possessed(key_ref)) kperm |= key->perm >> 24; - kperm = kperm & perm & KEY_ALL; + kperm = kperm & perm & KEY_NEED_ALL; if (kperm != perm) return -EACCES; /* let LSM be the final arbiter */ - return security_key_permission(key_ref, context, perm); - -} /* end key_task_permission() */ - + return security_key_permission(key_ref, cred, perm); +} EXPORT_SYMBOL(key_task_permission); -/*****************************************************************************/ -/* - * validate a key +/** + * key_validate - Validate a key. + * @key: The key to be validated. + * + * Check that a key is valid, returning 0 if the key is okay, -ENOKEY if the + * key is invalidated, -EKEYREVOKED if the key's type has been removed or if + * the key has been revoked or -EKEYEXPIRED if the key has expired. */ -int key_validate(struct key *key) +int key_validate(const struct key *key) { - struct timespec now; - int ret = 0; - - if (key) { - /* check it's still accessible */ - ret = -EKEYREVOKED; - if (test_bit(KEY_FLAG_REVOKED, &key->flags) || - test_bit(KEY_FLAG_DEAD, &key->flags)) - goto error; - - /* check it hasn't expired */ - ret = 0; - if (key->expiry) { - now = current_kernel_time(); - if (now.tv_sec >= key->expiry) - ret = -EKEYEXPIRED; - } - } + unsigned long flags = key->flags; + + if (flags & (1 << KEY_FLAG_INVALIDATED)) + return -ENOKEY; - error: - return ret; + /* check it's still accessible */ + if (flags & ((1 << KEY_FLAG_REVOKED) | + (1 << KEY_FLAG_DEAD))) + return -EKEYREVOKED; -} /* end key_validate() */ + /* check it hasn't expired */ + if (key->expiry) { + struct timespec now = current_kernel_time(); + if (now.tv_sec >= key->expiry) + return -EKEYEXPIRED; + } + return 0; +} EXPORT_SYMBOL(key_validate); diff --git a/security/keys/persistent.c b/security/keys/persistent.c new file mode 100644 index 00000000000..c9fae5ea89f --- /dev/null +++ b/security/keys/persistent.c @@ -0,0 +1,167 @@ +/* General persistent per-UID keyrings register + * + * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include <linux/user_namespace.h> +#include "internal.h" + +unsigned persistent_keyring_expiry = 3 * 24 * 3600; /* Expire after 3 days of non-use */ + +/* + * Create the persistent keyring register for the current user namespace. + * + * Called with the namespace's sem locked for writing. + */ +static int key_create_persistent_register(struct user_namespace *ns) +{ + struct key *reg = keyring_alloc(".persistent_register", + KUIDT_INIT(0), KGIDT_INIT(0), + current_cred(), + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ), + KEY_ALLOC_NOT_IN_QUOTA, NULL); + if (IS_ERR(reg)) + return PTR_ERR(reg); + + ns->persistent_keyring_register = reg; + return 0; +} + +/* + * Create the persistent keyring for the specified user. + * + * Called with the namespace's sem locked for writing. + */ +static key_ref_t key_create_persistent(struct user_namespace *ns, kuid_t uid, + struct keyring_index_key *index_key) +{ + struct key *persistent; + key_ref_t reg_ref, persistent_ref; + + if (!ns->persistent_keyring_register) { + long err = key_create_persistent_register(ns); + if (err < 0) + return ERR_PTR(err); + } else { + reg_ref = make_key_ref(ns->persistent_keyring_register, true); + persistent_ref = find_key_to_update(reg_ref, index_key); + if (persistent_ref) + return persistent_ref; + } + + persistent = keyring_alloc(index_key->description, + uid, INVALID_GID, current_cred(), + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ), + KEY_ALLOC_NOT_IN_QUOTA, + ns->persistent_keyring_register); + if (IS_ERR(persistent)) + return ERR_CAST(persistent); + + return make_key_ref(persistent, true); +} + +/* + * Get the persistent keyring for a specific UID and link it to the nominated + * keyring. + */ +static long key_get_persistent(struct user_namespace *ns, kuid_t uid, + key_ref_t dest_ref) +{ + struct keyring_index_key index_key; + struct key *persistent; + key_ref_t reg_ref, persistent_ref; + char buf[32]; + long ret; + + /* Look in the register if it exists */ + index_key.type = &key_type_keyring; + index_key.description = buf; + index_key.desc_len = sprintf(buf, "_persistent.%u", from_kuid(ns, uid)); + + if (ns->persistent_keyring_register) { + reg_ref = make_key_ref(ns->persistent_keyring_register, true); + down_read(&ns->persistent_keyring_register_sem); + persistent_ref = find_key_to_update(reg_ref, &index_key); + up_read(&ns->persistent_keyring_register_sem); + + if (persistent_ref) + goto found; + } + + /* It wasn't in the register, so we'll need to create it. We might + * also need to create the register. + */ + down_write(&ns->persistent_keyring_register_sem); + persistent_ref = key_create_persistent(ns, uid, &index_key); + up_write(&ns->persistent_keyring_register_sem); + if (!IS_ERR(persistent_ref)) + goto found; + + return PTR_ERR(persistent_ref); + +found: + ret = key_task_permission(persistent_ref, current_cred(), KEY_NEED_LINK); + if (ret == 0) { + persistent = key_ref_to_ptr(persistent_ref); + ret = key_link(key_ref_to_ptr(dest_ref), persistent); + if (ret == 0) { + key_set_timeout(persistent, persistent_keyring_expiry); + ret = persistent->serial; + } + } + + key_ref_put(persistent_ref); + return ret; +} + +/* + * Get the persistent keyring for a specific UID and link it to the nominated + * keyring. + */ +long keyctl_get_persistent(uid_t _uid, key_serial_t destid) +{ + struct user_namespace *ns = current_user_ns(); + key_ref_t dest_ref; + kuid_t uid; + long ret; + + /* -1 indicates the current user */ + if (_uid == (uid_t)-1) { + uid = current_uid(); + } else { + uid = make_kuid(ns, _uid); + if (!uid_valid(uid)) + return -EINVAL; + + /* You can only see your own persistent cache if you're not + * sufficiently privileged. + */ + if (!uid_eq(uid, current_uid()) && + !uid_eq(uid, current_euid()) && + !ns_capable(ns, CAP_SETUID)) + return -EPERM; + } + + /* There must be a destination keyring */ + dest_ref = lookup_user_key(destid, KEY_LOOKUP_CREATE, KEY_NEED_WRITE); + if (IS_ERR(dest_ref)) + return PTR_ERR(dest_ref); + if (key_ref_to_ptr(dest_ref)->type != &key_type_keyring) { + ret = -ENOTDIR; + goto out_put_dest; + } + + ret = key_get_persistent(ns, uid, dest_ref); + +out_put_dest: + key_ref_put(dest_ref); + return ret; +} diff --git a/security/keys/proc.c b/security/keys/proc.c index 694126003ed..d3f6f2fd21d 100644 --- a/security/keys/proc.c +++ b/security/keys/proc.c @@ -1,4 +1,4 @@ -/* proc.c: proc files for key database enumeration +/* procfs files for key database enumeration * * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) @@ -12,7 +12,6 @@ #include <linux/module.h> #include <linux/init.h> #include <linux/sched.h> -#include <linux/slab.h> #include <linux/fs.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> @@ -61,71 +60,122 @@ static const struct file_operations proc_key_users_fops = { .release = seq_release, }; -/*****************************************************************************/ /* - * declare the /proc files + * Declare the /proc files. */ static int __init key_proc_init(void) { struct proc_dir_entry *p; #ifdef CONFIG_KEYS_DEBUG_PROC_KEYS - p = create_proc_entry("keys", 0, NULL); + p = proc_create("keys", 0, NULL, &proc_keys_fops); if (!p) panic("Cannot create /proc/keys\n"); - - p->proc_fops = &proc_keys_fops; #endif - p = create_proc_entry("key-users", 0, NULL); + p = proc_create("key-users", 0, NULL, &proc_key_users_fops); if (!p) panic("Cannot create /proc/key-users\n"); - p->proc_fops = &proc_key_users_fops; - return 0; - -} /* end key_proc_init() */ +} __initcall(key_proc_init); -/*****************************************************************************/ /* - * implement "/proc/keys" to provides a list of the keys on the system + * Implement "/proc/keys" to provide a list of the keys on the system that + * grant View permission to the caller. */ #ifdef CONFIG_KEYS_DEBUG_PROC_KEYS +static struct rb_node *key_serial_next(struct seq_file *p, struct rb_node *n) +{ + struct user_namespace *user_ns = seq_user_ns(p); + + n = rb_next(n); + while (n) { + struct key *key = rb_entry(n, struct key, serial_node); + if (kuid_has_mapping(user_ns, key->user->uid)) + break; + n = rb_next(n); + } + return n; +} + static int proc_keys_open(struct inode *inode, struct file *file) { return seq_open(file, &proc_keys_ops); +} + +static struct key *find_ge_key(struct seq_file *p, key_serial_t id) +{ + struct user_namespace *user_ns = seq_user_ns(p); + struct rb_node *n = key_serial_tree.rb_node; + struct key *minkey = NULL; + + while (n) { + struct key *key = rb_entry(n, struct key, serial_node); + if (id < key->serial) { + if (!minkey || minkey->serial > key->serial) + minkey = key; + n = n->rb_left; + } else if (id > key->serial) { + n = n->rb_right; + } else { + minkey = key; + break; + } + key = NULL; + } + + if (!minkey) + return NULL; + for (;;) { + if (kuid_has_mapping(user_ns, minkey->user->uid)) + return minkey; + n = rb_next(&minkey->serial_node); + if (!n) + return NULL; + minkey = rb_entry(n, struct key, serial_node); + } } static void *proc_keys_start(struct seq_file *p, loff_t *_pos) + __acquires(key_serial_lock) { - struct rb_node *_p; - loff_t pos = *_pos; + key_serial_t pos = *_pos; + struct key *key; spin_lock(&key_serial_lock); - _p = rb_first(&key_serial_tree); - while (pos > 0 && _p) { - pos--; - _p = rb_next(_p); - } - - return _p; + if (*_pos > INT_MAX) + return NULL; + key = find_ge_key(p, pos); + if (!key) + return NULL; + *_pos = key->serial; + return &key->serial_node; +} +static inline key_serial_t key_node_serial(struct rb_node *n) +{ + struct key *key = rb_entry(n, struct key, serial_node); + return key->serial; } static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos) { - (*_pos)++; - return rb_next((struct rb_node *) v); + struct rb_node *n; + n = key_serial_next(p, v); + if (n) + *_pos = key_node_serial(n); + return n; } static void proc_keys_stop(struct seq_file *p, void *v) + __releases(key_serial_lock) { spin_unlock(&key_serial_lock); } @@ -136,12 +186,39 @@ static int proc_keys_show(struct seq_file *m, void *v) struct key *key = rb_entry(_p, struct key, serial_node); struct timespec now; unsigned long timo; + key_ref_t key_ref, skey_ref; char xbuf[12]; int rc; + struct keyring_search_context ctx = { + .index_key.type = key->type, + .index_key.description = key->description, + .cred = current_cred(), + .match = lookup_user_key_possessed, + .match_data = key, + .flags = (KEYRING_SEARCH_NO_STATE_CHECK | + KEYRING_SEARCH_LOOKUP_DIRECT), + }; + + key_ref = make_key_ref(key, 0); + + /* determine if the key is possessed by this process (a test we can + * skip if the key does not indicate the possessor can view it + */ + if (key->perm & KEY_POS_VIEW) { + skey_ref = search_my_process_keyrings(&ctx); + if (!IS_ERR(skey_ref)) { + key_ref_put(skey_ref); + key_ref = make_key_ref(key, 1); + } + } + /* check whether the current task is allowed to view the key (assuming - * non-possession) */ - rc = key_task_permission(make_key_ref(key, 0), current, KEY_VIEW); + * non-possession) + * - the caller holds a spinlock, and thus the RCU read lock, making our + * access to __current_cred() safe + */ + rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW); if (rc < 0) return 0; @@ -152,11 +229,9 @@ static int proc_keys_show(struct seq_file *m, void *v) /* come up with a suitable timeout value */ if (key->expiry == 0) { memcpy(xbuf, "perm", 5); - } - else if (now.tv_sec >= key->expiry) { + } else if (now.tv_sec >= key->expiry) { memcpy(xbuf, "expd", 5); - } - else { + } else { timo = key->expiry - now.tv_sec; if (timo < 60) @@ -174,7 +249,7 @@ static int proc_keys_show(struct seq_file *m, void *v) #define showflag(KEY, LETTER, FLAG) \ (test_bit(FLAG, &(KEY)->flags) ? LETTER : '-') - seq_printf(m, "%08x %c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ", + seq_printf(m, "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ", key->serial, showflag(key, 'I', KEY_FLAG_INSTANTIATED), showflag(key, 'R', KEY_FLAG_REVOKED), @@ -182,11 +257,12 @@ static int proc_keys_show(struct seq_file *m, void *v) showflag(key, 'Q', KEY_FLAG_IN_QUOTA), showflag(key, 'U', KEY_FLAG_USER_CONSTRUCT), showflag(key, 'N', KEY_FLAG_NEGATIVE), + showflag(key, 'i', KEY_FLAG_INVALIDATED), atomic_read(&key->usage), xbuf, key->perm, - key->uid, - key->gid, + from_kuid_munged(seq_user_ns(m), key->uid), + from_kgid_munged(seq_user_ns(m), key->gid), key->type->name); #undef showflag @@ -196,48 +272,67 @@ static int proc_keys_show(struct seq_file *m, void *v) seq_putc(m, '\n'); rcu_read_unlock(); - return 0; - } #endif /* CONFIG_KEYS_DEBUG_PROC_KEYS */ -/*****************************************************************************/ +static struct rb_node *__key_user_next(struct user_namespace *user_ns, struct rb_node *n) +{ + while (n) { + struct key_user *user = rb_entry(n, struct key_user, node); + if (kuid_has_mapping(user_ns, user->uid)) + break; + n = rb_next(n); + } + return n; +} + +static struct rb_node *key_user_next(struct user_namespace *user_ns, struct rb_node *n) +{ + return __key_user_next(user_ns, rb_next(n)); +} + +static struct rb_node *key_user_first(struct user_namespace *user_ns, struct rb_root *r) +{ + struct rb_node *n = rb_first(r); + return __key_user_next(user_ns, n); +} + /* - * implement "/proc/key-users" to provides a list of the key users + * Implement "/proc/key-users" to provides a list of the key users and their + * quotas. */ static int proc_key_users_open(struct inode *inode, struct file *file) { return seq_open(file, &proc_key_users_ops); - } static void *proc_key_users_start(struct seq_file *p, loff_t *_pos) + __acquires(key_user_lock) { struct rb_node *_p; loff_t pos = *_pos; spin_lock(&key_user_lock); - _p = rb_first(&key_user_tree); + _p = key_user_first(seq_user_ns(p), &key_user_tree); while (pos > 0 && _p) { pos--; - _p = rb_next(_p); + _p = key_user_next(seq_user_ns(p), _p); } return _p; - } static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos) { (*_pos)++; - return rb_next((struct rb_node *) v); - + return key_user_next(seq_user_ns(p), (struct rb_node *)v); } static void proc_key_users_stop(struct seq_file *p, void *v) + __releases(key_user_lock) { spin_unlock(&key_user_lock); } @@ -246,18 +341,20 @@ static int proc_key_users_show(struct seq_file *m, void *v) { struct rb_node *_p = v; struct key_user *user = rb_entry(_p, struct key_user, node); + unsigned maxkeys = uid_eq(user->uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxkeys : key_quota_maxkeys; + unsigned maxbytes = uid_eq(user->uid, GLOBAL_ROOT_UID) ? + key_quota_root_maxbytes : key_quota_maxbytes; seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n", - user->uid, + from_kuid_munged(seq_user_ns(m), user->uid), atomic_read(&user->usage), atomic_read(&user->nkeys), atomic_read(&user->nikeys), user->qnkeys, - KEYQUOTA_MAX_KEYS, + maxkeys, user->qnbytes, - KEYQUOTA_MAX_BYTES - ); + maxbytes); return 0; - } diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index c886a2bb792..0cf8a130a26 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -1,6 +1,6 @@ -/* process_keys.c: management of a process's keyrings +/* Manage a process's keyrings * - * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or @@ -12,396 +12,317 @@ #include <linux/module.h> #include <linux/init.h> #include <linux/sched.h> -#include <linux/slab.h> #include <linux/keyctl.h> #include <linux/fs.h> #include <linux/err.h> #include <linux/mutex.h> +#include <linux/security.h> +#include <linux/user_namespace.h> #include <asm/uaccess.h> #include "internal.h" -/* session keyring create vs join semaphore */ +/* Session keyring create vs join semaphore */ static DEFINE_MUTEX(key_session_mutex); -/* the root user's tracking struct */ +/* User keyring creation semaphore */ +static DEFINE_MUTEX(key_user_keyring_mutex); + +/* The root user's tracking struct */ struct key_user root_key_user = { .usage = ATOMIC_INIT(3), .cons_lock = __MUTEX_INITIALIZER(root_key_user.cons_lock), .lock = __SPIN_LOCK_UNLOCKED(root_key_user.lock), .nkeys = ATOMIC_INIT(2), .nikeys = ATOMIC_INIT(2), - .uid = 0, -}; - -/* the root user's UID keyring */ -struct key root_user_keyring = { - .usage = ATOMIC_INIT(1), - .serial = 2, - .type = &key_type_keyring, - .user = &root_key_user, - .sem = __RWSEM_INITIALIZER(root_user_keyring.sem), - .perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL, - .flags = 1 << KEY_FLAG_INSTANTIATED, - .description = "_uid.0", -#ifdef KEY_DEBUGGING - .magic = KEY_DEBUG_MAGIC, -#endif + .uid = GLOBAL_ROOT_UID, }; -/* the root user's default session keyring */ -struct key root_session_keyring = { - .usage = ATOMIC_INIT(1), - .serial = 1, - .type = &key_type_keyring, - .user = &root_key_user, - .sem = __RWSEM_INITIALIZER(root_session_keyring.sem), - .perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL, - .flags = 1 << KEY_FLAG_INSTANTIATED, - .description = "_uid_ses.0", -#ifdef KEY_DEBUGGING - .magic = KEY_DEBUG_MAGIC, -#endif -}; - -/*****************************************************************************/ /* - * allocate the keyrings to be associated with a UID + * Install the user and user session keyrings for the current process's UID. */ -int alloc_uid_keyring(struct user_struct *user, - struct task_struct *ctx) +int install_user_keyrings(void) { + struct user_struct *user; + const struct cred *cred; struct key *uid_keyring, *session_keyring; + key_perm_t user_keyring_perm; char buf[20]; int ret; + uid_t uid; - /* concoct a default session keyring */ - sprintf(buf, "_uid_ses.%u", user->uid); + user_keyring_perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_ALL; + cred = current_cred(); + user = cred->user; + uid = from_kuid(cred->user_ns, user->uid); - session_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx, - KEY_ALLOC_IN_QUOTA, NULL); - if (IS_ERR(session_keyring)) { - ret = PTR_ERR(session_keyring); - goto error; + kenter("%p{%u}", user, uid); + + if (user->uid_keyring && user->session_keyring) { + kleave(" = 0 [exist]"); + return 0; } - /* and a UID specific keyring, pointed to by the default session - * keyring */ - sprintf(buf, "_uid.%u", user->uid); + mutex_lock(&key_user_keyring_mutex); + ret = 0; - uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, ctx, - KEY_ALLOC_IN_QUOTA, session_keyring); - if (IS_ERR(uid_keyring)) { - key_put(session_keyring); - ret = PTR_ERR(uid_keyring); - goto error; + if (!user->uid_keyring) { + /* get the UID-specific keyring + * - there may be one in existence already as it may have been + * pinned by a session, but the user_struct pointing to it + * may have been destroyed by setuid */ + sprintf(buf, "_uid.%u", uid); + + uid_keyring = find_keyring_by_name(buf, true); + if (IS_ERR(uid_keyring)) { + uid_keyring = keyring_alloc(buf, user->uid, INVALID_GID, + cred, user_keyring_perm, + KEY_ALLOC_IN_QUOTA, NULL); + if (IS_ERR(uid_keyring)) { + ret = PTR_ERR(uid_keyring); + goto error; + } + } + + /* get a default session keyring (which might also exist + * already) */ + sprintf(buf, "_uid_ses.%u", uid); + + session_keyring = find_keyring_by_name(buf, true); + if (IS_ERR(session_keyring)) { + session_keyring = + keyring_alloc(buf, user->uid, INVALID_GID, + cred, user_keyring_perm, + KEY_ALLOC_IN_QUOTA, NULL); + if (IS_ERR(session_keyring)) { + ret = PTR_ERR(session_keyring); + goto error_release; + } + + /* we install a link from the user session keyring to + * the user keyring */ + ret = key_link(session_keyring, uid_keyring); + if (ret < 0) + goto error_release_both; + } + + /* install the keyrings */ + user->uid_keyring = uid_keyring; + user->session_keyring = session_keyring; } - /* install the keyrings */ - user->uid_keyring = uid_keyring; - user->session_keyring = session_keyring; - ret = 0; + mutex_unlock(&key_user_keyring_mutex); + kleave(" = 0"); + return 0; +error_release_both: + key_put(session_keyring); +error_release: + key_put(uid_keyring); error: + mutex_unlock(&key_user_keyring_mutex); + kleave(" = %d", ret); return ret; +} -} /* end alloc_uid_keyring() */ - -/*****************************************************************************/ /* - * deal with the UID changing + * Install a fresh thread keyring directly to new credentials. This keyring is + * allowed to overrun the quota. */ -void switch_uid_keyring(struct user_struct *new_user) +int install_thread_keyring_to_cred(struct cred *new) { -#if 0 /* do nothing for now */ - struct key *old; - - /* switch to the new user's session keyring if we were running under - * root's default session keyring */ - if (new_user->uid != 0 && - current->session_keyring == &root_session_keyring - ) { - atomic_inc(&new_user->session_keyring->usage); - - task_lock(current); - old = current->session_keyring; - current->session_keyring = new_user->session_keyring; - task_unlock(current); + struct key *keyring; - key_put(old); - } -#endif + keyring = keyring_alloc("_tid", new->uid, new->gid, new, + KEY_POS_ALL | KEY_USR_VIEW, + KEY_ALLOC_QUOTA_OVERRUN, NULL); + if (IS_ERR(keyring)) + return PTR_ERR(keyring); -} /* end switch_uid_keyring() */ + new->thread_keyring = keyring; + return 0; +} -/*****************************************************************************/ /* - * install a fresh thread keyring, discarding the old one + * Install a fresh thread keyring, discarding the old one. */ -int install_thread_keyring(struct task_struct *tsk) +static int install_thread_keyring(void) { - struct key *keyring, *old; - char buf[20]; + struct cred *new; int ret; - sprintf(buf, "_tid.%u", tsk->pid); + new = prepare_creds(); + if (!new) + return -ENOMEM; - keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, - KEY_ALLOC_QUOTA_OVERRUN, NULL); - if (IS_ERR(keyring)) { - ret = PTR_ERR(keyring); - goto error; - } - - task_lock(tsk); - old = tsk->thread_keyring; - tsk->thread_keyring = keyring; - task_unlock(tsk); - - ret = 0; + BUG_ON(new->thread_keyring); - key_put(old); -error: - return ret; + ret = install_thread_keyring_to_cred(new); + if (ret < 0) { + abort_creds(new); + return ret; + } -} /* end install_thread_keyring() */ + return commit_creds(new); +} -/*****************************************************************************/ /* - * make sure a process keyring is installed + * Install a process keyring directly to a credentials struct. + * + * Returns -EEXIST if there was already a process keyring, 0 if one installed, + * and other value on any other error */ -int install_process_keyring(struct task_struct *tsk) +int install_process_keyring_to_cred(struct cred *new) { struct key *keyring; - char buf[20]; - int ret; - might_sleep(); + if (new->process_keyring) + return -EEXIST; - if (!tsk->signal->process_keyring) { - sprintf(buf, "_pid.%u", tsk->tgid); + keyring = keyring_alloc("_pid", new->uid, new->gid, new, + KEY_POS_ALL | KEY_USR_VIEW, + KEY_ALLOC_QUOTA_OVERRUN, NULL); + if (IS_ERR(keyring)) + return PTR_ERR(keyring); - keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, - KEY_ALLOC_QUOTA_OVERRUN, NULL); - if (IS_ERR(keyring)) { - ret = PTR_ERR(keyring); - goto error; - } + new->process_keyring = keyring; + return 0; +} - /* attach keyring */ - spin_lock_irq(&tsk->sighand->siglock); - if (!tsk->signal->process_keyring) { - tsk->signal->process_keyring = keyring; - keyring = NULL; - } - spin_unlock_irq(&tsk->sighand->siglock); +/* + * Make sure a process keyring is installed for the current process. The + * existing process keyring is not replaced. + * + * Returns 0 if there is a process keyring by the end of this function, some + * error otherwise. + */ +static int install_process_keyring(void) +{ + struct cred *new; + int ret; - key_put(keyring); - } + new = prepare_creds(); + if (!new) + return -ENOMEM; - ret = 0; -error: - return ret; + ret = install_process_keyring_to_cred(new); + if (ret < 0) { + abort_creds(new); + return ret != -EEXIST ? ret : 0; + } -} /* end install_process_keyring() */ + return commit_creds(new); +} -/*****************************************************************************/ /* - * install a session keyring, discarding the old one - * - if a keyring is not supplied, an empty one is invented + * Install a session keyring directly to a credentials struct. */ -static int install_session_keyring(struct task_struct *tsk, - struct key *keyring) +int install_session_keyring_to_cred(struct cred *cred, struct key *keyring) { unsigned long flags; struct key *old; - char buf[20]; might_sleep(); /* create an empty session keyring */ if (!keyring) { - sprintf(buf, "_ses.%u", tsk->tgid); - flags = KEY_ALLOC_QUOTA_OVERRUN; - if (tsk->signal->session_keyring) + if (cred->session_keyring) flags = KEY_ALLOC_IN_QUOTA; - keyring = keyring_alloc(buf, tsk->uid, tsk->gid, tsk, + keyring = keyring_alloc("_ses", cred->uid, cred->gid, cred, + KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ, flags, NULL); if (IS_ERR(keyring)) return PTR_ERR(keyring); - } - else { - atomic_inc(&keyring->usage); + } else { + __key_get(keyring); } /* install the keyring */ - spin_lock_irq(&tsk->sighand->siglock); - old = tsk->signal->session_keyring; - rcu_assign_pointer(tsk->signal->session_keyring, keyring); - spin_unlock_irq(&tsk->sighand->siglock); - - /* we're using RCU on the pointer, but there's no point synchronising - * on it if it didn't previously point to anything */ - if (old) { - synchronize_rcu(); - key_put(old); - } - - return 0; - -} /* end install_session_keyring() */ - -/*****************************************************************************/ -/* - * copy the keys in a thread group for fork without CLONE_THREAD - */ -int copy_thread_group_keys(struct task_struct *tsk) -{ - key_check(current->thread_group->session_keyring); - key_check(current->thread_group->process_keyring); - - /* no process keyring yet */ - tsk->signal->process_keyring = NULL; + old = cred->session_keyring; + rcu_assign_pointer(cred->session_keyring, keyring); - /* same session keyring */ - rcu_read_lock(); - tsk->signal->session_keyring = - key_get(rcu_dereference(current->signal->session_keyring)); - rcu_read_unlock(); - - return 0; - -} /* end copy_thread_group_keys() */ - -/*****************************************************************************/ -/* - * copy the keys for fork - */ -int copy_keys(unsigned long clone_flags, struct task_struct *tsk) -{ - key_check(tsk->thread_keyring); - key_check(tsk->request_key_auth); - - /* no thread keyring yet */ - tsk->thread_keyring = NULL; - - /* copy the request_key() authorisation for this thread */ - key_get(tsk->request_key_auth); + if (old) + key_put(old); return 0; +} -} /* end copy_keys() */ - -/*****************************************************************************/ /* - * dispose of thread group keys upon thread group destruction + * Install a session keyring, discarding the old one. If a keyring is not + * supplied, an empty one is invented. */ -void exit_thread_group_keys(struct signal_struct *tg) +static int install_session_keyring(struct key *keyring) { - key_put(tg->session_keyring); - key_put(tg->process_keyring); - -} /* end exit_thread_group_keys() */ - -/*****************************************************************************/ -/* - * dispose of per-thread keys upon thread exit - */ -void exit_keys(struct task_struct *tsk) -{ - key_put(tsk->thread_keyring); - key_put(tsk->request_key_auth); - -} /* end exit_keys() */ - -/*****************************************************************************/ -/* - * deal with execve() - */ -int exec_keys(struct task_struct *tsk) -{ - struct key *old; - - /* newly exec'd tasks don't get a thread keyring */ - task_lock(tsk); - old = tsk->thread_keyring; - tsk->thread_keyring = NULL; - task_unlock(tsk); - - key_put(old); - - /* discard the process keyring from a newly exec'd task */ - spin_lock_irq(&tsk->sighand->siglock); - old = tsk->signal->process_keyring; - tsk->signal->process_keyring = NULL; - spin_unlock_irq(&tsk->sighand->siglock); - - key_put(old); - - return 0; + struct cred *new; + int ret; -} /* end exec_keys() */ + new = prepare_creds(); + if (!new) + return -ENOMEM; -/*****************************************************************************/ -/* - * deal with SUID programs - * - we might want to make this invent a new session keyring - */ -int suid_keys(struct task_struct *tsk) -{ - return 0; + ret = install_session_keyring_to_cred(new, keyring); + if (ret < 0) { + abort_creds(new); + return ret; + } -} /* end suid_keys() */ + return commit_creds(new); +} -/*****************************************************************************/ /* - * the filesystem user ID changed + * Handle the fsuid changing. */ void key_fsuid_changed(struct task_struct *tsk) { /* update the ownership of the thread keyring */ - if (tsk->thread_keyring) { - down_write(&tsk->thread_keyring->sem); - tsk->thread_keyring->uid = tsk->fsuid; - up_write(&tsk->thread_keyring->sem); + BUG_ON(!tsk->cred); + if (tsk->cred->thread_keyring) { + down_write(&tsk->cred->thread_keyring->sem); + tsk->cred->thread_keyring->uid = tsk->cred->fsuid; + up_write(&tsk->cred->thread_keyring->sem); } +} -} /* end key_fsuid_changed() */ - -/*****************************************************************************/ /* - * the filesystem group ID changed + * Handle the fsgid changing. */ void key_fsgid_changed(struct task_struct *tsk) { /* update the ownership of the thread keyring */ - if (tsk->thread_keyring) { - down_write(&tsk->thread_keyring->sem); - tsk->thread_keyring->gid = tsk->fsgid; - up_write(&tsk->thread_keyring->sem); + BUG_ON(!tsk->cred); + if (tsk->cred->thread_keyring) { + down_write(&tsk->cred->thread_keyring->sem); + tsk->cred->thread_keyring->gid = tsk->cred->fsgid; + up_write(&tsk->cred->thread_keyring->sem); } +} -} /* end key_fsgid_changed() */ - -/*****************************************************************************/ /* - * search the process keyrings for the first matching key - * - we use the supplied match function to see if the description (or other - * feature of interest) matches - * - we return -EAGAIN if we didn't find any matching key - * - we return -ENOKEY if we found only negative matching keys + * Search the process keyrings attached to the supplied cred for the first + * matching key. + * + * The search criteria are the type and the match function. The description is + * given to the match function as a parameter, but doesn't otherwise influence + * the search. Typically the match function will compare the description + * parameter to the key's description. + * + * This can only search keyrings that grant Search permission to the supplied + * credentials. Keyrings linked to searched keyrings will also be searched if + * they grant Search permission too. Keys can only be found if they grant + * Search permission to the credentials. + * + * Returns a pointer to the key with the key usage count incremented if + * successful, -EAGAIN if we didn't find any matching key or -ENOKEY if we only + * matched negative keys. + * + * In the case of a successful return, the possession attribute is set on the + * returned key reference. */ -key_ref_t search_process_keyrings(struct key_type *type, - const void *description, - key_match_func_t match, - struct task_struct *context) +key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx) { - struct request_key_auth *rka; key_ref_t key_ref, ret, err; - might_sleep(); - /* we want to return -EAGAIN or -ENOKEY if any of the keyrings were * searchable, but we failed to find a key or we found a negative key; * otherwise we want to return a sample error (probably -EACCES) if @@ -414,17 +335,14 @@ key_ref_t search_process_keyrings(struct key_type *type, err = ERR_PTR(-EAGAIN); /* search the thread keyring first */ - if (context->thread_keyring) { + if (ctx->cred->thread_keyring) { key_ref = keyring_search_aux( - make_key_ref(context->thread_keyring, 1), - context, type, description, match); + make_key_ref(ctx->cred->thread_keyring, 1), ctx); if (!IS_ERR(key_ref)) goto found; switch (PTR_ERR(key_ref)) { case -EAGAIN: /* no key */ - if (ret) - break; case -ENOKEY: /* negative key */ ret = key_ref; break; @@ -435,10 +353,9 @@ key_ref_t search_process_keyrings(struct key_type *type, } /* search the process keyring second */ - if (context->signal->process_keyring) { + if (ctx->cred->process_keyring) { key_ref = keyring_search_aux( - make_key_ref(context->signal->process_keyring, 1), - context, type, description, match); + make_key_ref(ctx->cred->process_keyring, 1), ctx); if (!IS_ERR(key_ref)) goto found; @@ -456,13 +373,11 @@ key_ref_t search_process_keyrings(struct key_type *type, } /* search the session keyring */ - if (context->signal->session_keyring) { + if (ctx->cred->session_keyring) { rcu_read_lock(); key_ref = keyring_search_aux( - make_key_ref(rcu_dereference( - context->signal->session_keyring), - 1), - context, type, description, match); + make_key_ref(rcu_dereference(ctx->cred->session_keyring), 1), + ctx); rcu_read_unlock(); if (!IS_ERR(key_ref)) @@ -481,10 +396,10 @@ key_ref_t search_process_keyrings(struct key_type *type, } } /* or search the user-session keyring */ - else { + else if (ctx->cred->user->session_keyring) { key_ref = keyring_search_aux( - make_key_ref(context->user->session_keyring, 1), - context, type, description, match); + make_key_ref(ctx->cred->user->session_keyring, 1), + ctx); if (!IS_ERR(key_ref)) goto found; @@ -501,155 +416,243 @@ key_ref_t search_process_keyrings(struct key_type *type, } } + /* no key - decide on the error we're going to go for */ + key_ref = ret ? ret : err; + +found: + return key_ref; +} + +/* + * Search the process keyrings attached to the supplied cred for the first + * matching key in the manner of search_my_process_keyrings(), but also search + * the keys attached to the assumed authorisation key using its credentials if + * one is available. + * + * Return same as search_my_process_keyrings(). + */ +key_ref_t search_process_keyrings(struct keyring_search_context *ctx) +{ + struct request_key_auth *rka; + key_ref_t key_ref, ret = ERR_PTR(-EACCES), err; + + might_sleep(); + + key_ref = search_my_process_keyrings(ctx); + if (!IS_ERR(key_ref)) + goto found; + err = key_ref; + /* if this process has an instantiation authorisation key, then we also * search the keyrings of the process mentioned there * - we don't permit access to request_key auth keys via this method */ - if (context->request_key_auth && - context == current && - type != &key_type_request_key_auth + if (ctx->cred->request_key_auth && + ctx->cred == current_cred() && + ctx->index_key.type != &key_type_request_key_auth ) { + const struct cred *cred = ctx->cred; + /* defend against the auth key being revoked */ - down_read(&context->request_key_auth->sem); + down_read(&cred->request_key_auth->sem); - if (key_validate(context->request_key_auth) == 0) { - rka = context->request_key_auth->payload.data; + if (key_validate(ctx->cred->request_key_auth) == 0) { + rka = ctx->cred->request_key_auth->payload.data; - key_ref = search_process_keyrings(type, description, - match, rka->context); + ctx->cred = rka->cred; + key_ref = search_process_keyrings(ctx); + ctx->cred = cred; - up_read(&context->request_key_auth->sem); + up_read(&cred->request_key_auth->sem); if (!IS_ERR(key_ref)) goto found; - switch (PTR_ERR(key_ref)) { - case -EAGAIN: /* no key */ - if (ret) - break; - case -ENOKEY: /* negative key */ - ret = key_ref; - break; - default: - err = key_ref; - break; - } + ret = key_ref; } else { - up_read(&context->request_key_auth->sem); + up_read(&cred->request_key_auth->sem); } } /* no key - decide on the error we're going to go for */ - key_ref = ret ? ret : err; + if (err == ERR_PTR(-ENOKEY) || ret == ERR_PTR(-ENOKEY)) + key_ref = ERR_PTR(-ENOKEY); + else if (err == ERR_PTR(-EACCES)) + key_ref = ret; + else + key_ref = err; found: return key_ref; +} -} /* end search_process_keyrings() */ - -/*****************************************************************************/ /* - * see if the key we're looking at is the target key + * See if the key we're looking at is the target key. */ -static int lookup_user_key_possessed(const struct key *key, const void *target) +int lookup_user_key_possessed(const struct key *key, const void *target) { return key == target; +} -} /* end lookup_user_key_possessed() */ - -/*****************************************************************************/ /* - * lookup a key given a key ID from userspace with a given permissions mask - * - don't create special keyrings unless so requested - * - partially constructed keys aren't found unless requested + * Look up a key ID given us by userspace with a given permissions mask to get + * the key it refers to. + * + * Flags can be passed to request that special keyrings be created if referred + * to directly, to permit partially constructed keys to be found and to skip + * validity and permission checks on the found key. + * + * Returns a pointer to the key with an incremented usage count if successful; + * -EINVAL if the key ID is invalid; -ENOKEY if the key ID does not correspond + * to a key or the best found key was a negative key; -EKEYREVOKED or + * -EKEYEXPIRED if the best found key was revoked or expired; -EACCES if the + * found key doesn't grant the requested permit or the LSM denied access to it; + * or -ENOMEM if a special keyring couldn't be created. + * + * In the case of a successful return, the possession attribute is set on the + * returned key reference. */ -key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id, - int create, int partial, key_perm_t perm) +key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags, + key_perm_t perm) { - key_ref_t key_ref, skey_ref; + struct keyring_search_context ctx = { + .match = lookup_user_key_possessed, + .flags = (KEYRING_SEARCH_NO_STATE_CHECK | + KEYRING_SEARCH_LOOKUP_DIRECT), + }; + struct request_key_auth *rka; struct key *key; + key_ref_t key_ref, skey_ref; int ret; - if (!context) - context = current; - +try_again: + ctx.cred = get_current_cred(); key_ref = ERR_PTR(-ENOKEY); switch (id) { case KEY_SPEC_THREAD_KEYRING: - if (!context->thread_keyring) { - if (!create) + if (!ctx.cred->thread_keyring) { + if (!(lflags & KEY_LOOKUP_CREATE)) goto error; - ret = install_thread_keyring(context); + ret = install_thread_keyring(); if (ret < 0) { - key = ERR_PTR(ret); + key_ref = ERR_PTR(ret); goto error; } + goto reget_creds; } - key = context->thread_keyring; - atomic_inc(&key->usage); + key = ctx.cred->thread_keyring; + __key_get(key); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_PROCESS_KEYRING: - if (!context->signal->process_keyring) { - if (!create) + if (!ctx.cred->process_keyring) { + if (!(lflags & KEY_LOOKUP_CREATE)) goto error; - ret = install_process_keyring(context); + ret = install_process_keyring(); if (ret < 0) { - key = ERR_PTR(ret); + key_ref = ERR_PTR(ret); goto error; } + goto reget_creds; } - key = context->signal->process_keyring; - atomic_inc(&key->usage); + key = ctx.cred->process_keyring; + __key_get(key); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_SESSION_KEYRING: - if (!context->signal->session_keyring) { + if (!ctx.cred->session_keyring) { /* always install a session keyring upon access if one * doesn't exist yet */ - ret = install_session_keyring( - context, context->user->session_keyring); + ret = install_user_keyrings(); if (ret < 0) goto error; + if (lflags & KEY_LOOKUP_CREATE) + ret = join_session_keyring(NULL); + else + ret = install_session_keyring( + ctx.cred->user->session_keyring); + + if (ret < 0) + goto error; + goto reget_creds; + } else if (ctx.cred->session_keyring == + ctx.cred->user->session_keyring && + lflags & KEY_LOOKUP_CREATE) { + ret = join_session_keyring(NULL); + if (ret < 0) + goto error; + goto reget_creds; } rcu_read_lock(); - key = rcu_dereference(context->signal->session_keyring); - atomic_inc(&key->usage); + key = rcu_dereference(ctx.cred->session_keyring); + __key_get(key); rcu_read_unlock(); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_USER_KEYRING: - key = context->user->uid_keyring; - atomic_inc(&key->usage); + if (!ctx.cred->user->uid_keyring) { + ret = install_user_keyrings(); + if (ret < 0) + goto error; + } + + key = ctx.cred->user->uid_keyring; + __key_get(key); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_USER_SESSION_KEYRING: - key = context->user->session_keyring; - atomic_inc(&key->usage); + if (!ctx.cred->user->session_keyring) { + ret = install_user_keyrings(); + if (ret < 0) + goto error; + } + + key = ctx.cred->user->session_keyring; + __key_get(key); key_ref = make_key_ref(key, 1); break; case KEY_SPEC_GROUP_KEYRING: /* group keyrings are not yet supported */ - key = ERR_PTR(-EINVAL); + key_ref = ERR_PTR(-EINVAL); goto error; case KEY_SPEC_REQKEY_AUTH_KEY: - key = context->request_key_auth; + key = ctx.cred->request_key_auth; if (!key) goto error; - atomic_inc(&key->usage); + __key_get(key); + key_ref = make_key_ref(key, 1); + break; + + case KEY_SPEC_REQUESTOR_KEYRING: + if (!ctx.cred->request_key_auth) + goto error; + + down_read(&ctx.cred->request_key_auth->sem); + if (test_bit(KEY_FLAG_REVOKED, + &ctx.cred->request_key_auth->flags)) { + key_ref = ERR_PTR(-EKEYREVOKED); + key = NULL; + } else { + rka = ctx.cred->request_key_auth->payload.data; + key = rka->dest_keyring; + __key_get(key); + } + up_read(&ctx.cred->request_key_auth->sem); + if (!key) + goto error; key_ref = make_key_ref(key, 1); break; @@ -667,9 +670,13 @@ key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id, key_ref = make_key_ref(key, 0); /* check to see if we possess the key */ - skey_ref = search_process_keyrings(key->type, key, - lookup_user_key_possessed, - current); + ctx.index_key.type = key->type; + ctx.index_key.description = key->description; + ctx.index_key.desc_len = strlen(key->description); + ctx.match_data = key; + kdebug("check possessed"); + skey_ref = search_process_keyrings(&ctx); + kdebug("possessed=%p", skey_ref); if (!IS_ERR(skey_ref)) { key_put(key); @@ -679,7 +686,14 @@ key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id, break; } - if (!partial) { + /* unlink does not use the nominated key in any way, so can skip all + * the permission checks as it is only concerned with the keyring */ + if (lflags & KEY_LOOKUP_FOR_UNLINK) { + ret = 0; + goto error; + } + + if (!(lflags & KEY_LOOKUP_PARTIAL)) { ret = wait_for_key_construction(key, true); switch (ret) { case -ERESTARTSYS: @@ -697,15 +711,19 @@ key_ref_t lookup_user_key(struct task_struct *context, key_serial_t id, } ret = -EIO; - if (!partial && !test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) + if (!(lflags & KEY_LOOKUP_PARTIAL) && + !test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) goto invalid_key; /* check the permissions */ - ret = key_task_permission(key_ref, context, perm); + ret = key_task_permission(key_ref, ctx.cred, perm); if (ret < 0) goto invalid_key; + key->last_used_at = current_kernel_time().tv_sec; + error: + put_cred(ctx.cred); return key_ref; invalid_key: @@ -713,63 +731,139 @@ invalid_key: key_ref = ERR_PTR(ret); goto error; -} /* end lookup_user_key() */ + /* if we attempted to install a keyring, then it may have caused new + * creds to be installed */ +reget_creds: + put_cred(ctx.cred); + goto try_again; +} -/*****************************************************************************/ /* - * join the named keyring as the session keyring if possible, or attempt to - * create a new one of that name if not - * - if the name is NULL, an empty anonymous keyring is installed instead - * - named session keyring joining is done with a semaphore held + * Join the named keyring as the session keyring if possible else attempt to + * create a new one of that name and join that. + * + * If the name is NULL, an empty anonymous keyring will be installed as the + * session keyring. + * + * Named session keyrings are joined with a semaphore held to prevent the + * keyrings from going away whilst the attempt is made to going them and also + * to prevent a race in creating compatible session keyrings. */ long join_session_keyring(const char *name) { - struct task_struct *tsk = current; + const struct cred *old; + struct cred *new; struct key *keyring; - long ret; + long ret, serial; + + new = prepare_creds(); + if (!new) + return -ENOMEM; + old = current_cred(); /* if no name is provided, install an anonymous keyring */ if (!name) { - ret = install_session_keyring(tsk, NULL); + ret = install_session_keyring_to_cred(new, NULL); if (ret < 0) goto error; - rcu_read_lock(); - ret = rcu_dereference(tsk->signal->session_keyring)->serial; - rcu_read_unlock(); - goto error; + serial = new->session_keyring->serial; + ret = commit_creds(new); + if (ret == 0) + ret = serial; + goto okay; } /* allow the user to join or create a named keyring */ mutex_lock(&key_session_mutex); /* look for an existing keyring of this name */ - keyring = find_keyring_by_name(name, 0); + keyring = find_keyring_by_name(name, false); if (PTR_ERR(keyring) == -ENOKEY) { /* not found - try and create a new one */ - keyring = keyring_alloc(name, tsk->uid, tsk->gid, tsk, - KEY_ALLOC_IN_QUOTA, NULL); + keyring = keyring_alloc( + name, old->uid, old->gid, old, + KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_LINK, + KEY_ALLOC_IN_QUOTA, NULL); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error2; } - } - else if (IS_ERR(keyring)) { + } else if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error2; + } else if (keyring == new->session_keyring) { + ret = 0; + goto error2; } /* we've got a keyring - now to install it */ - ret = install_session_keyring(tsk, keyring); + ret = install_session_keyring_to_cred(new, keyring); if (ret < 0) goto error2; + commit_creds(new); + mutex_unlock(&key_session_mutex); + ret = keyring->serial; key_put(keyring); +okay: + return ret; error2: mutex_unlock(&key_session_mutex); error: + abort_creds(new); return ret; +} + +/* + * Replace a process's session keyring on behalf of one of its children when + * the target process is about to resume userspace execution. + */ +void key_change_session_keyring(struct callback_head *twork) +{ + const struct cred *old = current_cred(); + struct cred *new = container_of(twork, struct cred, rcu); + + if (unlikely(current->flags & PF_EXITING)) { + put_cred(new); + return; + } + + new-> uid = old-> uid; + new-> euid = old-> euid; + new-> suid = old-> suid; + new->fsuid = old->fsuid; + new-> gid = old-> gid; + new-> egid = old-> egid; + new-> sgid = old-> sgid; + new->fsgid = old->fsgid; + new->user = get_uid(old->user); + new->user_ns = get_user_ns(old->user_ns); + new->group_info = get_group_info(old->group_info); + + new->securebits = old->securebits; + new->cap_inheritable = old->cap_inheritable; + new->cap_permitted = old->cap_permitted; + new->cap_effective = old->cap_effective; + new->cap_bset = old->cap_bset; + + new->jit_keyring = old->jit_keyring; + new->thread_keyring = key_get(old->thread_keyring); + new->process_keyring = key_get(old->process_keyring); + + security_transfer_creds(new, old); + + commit_creds(new); +} + +/* + * Make sure that root's user and user-session keyrings exist. + */ +static int __init init_root_keyring(void) +{ + return install_user_keyrings(); +} -} /* end join_session_keyring() */ +late_initcall(init_root_keyring); diff --git a/security/keys/request_key.c b/security/keys/request_key.c index 5ecc5057fb5..381411941cc 100644 --- a/security/keys/request_key.c +++ b/security/keys/request_key.c @@ -8,7 +8,7 @@ * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * - * See Documentation/keys-request-key.txt + * See Documentation/security/keys-request-key.txt */ #include <linux/module.h> @@ -16,8 +16,11 @@ #include <linux/kmod.h> #include <linux/err.h> #include <linux/keyctl.h> +#include <linux/slab.h> #include "internal.h" +#define key_negative_timeout 60 /* default timeout on a negative key's existence */ + /* * wait_on_bit() sleep function for uninterruptible waiting */ @@ -36,8 +39,14 @@ static int key_wait_bit_intr(void *flags) return signal_pending(current) ? -ERESTARTSYS : 0; } -/* - * call to complete the construction of a key +/** + * complete_request_key - Complete the construction of a key. + * @cons: The key construction record. + * @error: The success or failute of the construction. + * + * Complete the attempt to construct a key. The key will be negated + * if an error is indicated. The authorisation key will be revoked + * unconditionally. */ void complete_request_key(struct key_construction *cons, int error) { @@ -56,16 +65,58 @@ void complete_request_key(struct key_construction *cons, int error) EXPORT_SYMBOL(complete_request_key); /* - * request userspace finish the construction of a key + * Initialise a usermode helper that is going to have a specific session + * keyring. + * + * This is called in context of freshly forked kthread before kernel_execve(), + * so we can simply install the desired session_keyring at this point. + */ +static int umh_keys_init(struct subprocess_info *info, struct cred *cred) +{ + struct key *keyring = info->data; + + return install_session_keyring_to_cred(cred, keyring); +} + +/* + * Clean up a usermode helper with session keyring. + */ +static void umh_keys_cleanup(struct subprocess_info *info) +{ + struct key *keyring = info->data; + key_put(keyring); +} + +/* + * Call a usermode helper with a specific session keyring. + */ +static int call_usermodehelper_keys(char *path, char **argv, char **envp, + struct key *session_keyring, int wait) +{ + struct subprocess_info *info; + + info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL, + umh_keys_init, umh_keys_cleanup, + session_keyring); + if (!info) + return -ENOMEM; + + key_get(session_keyring); + return call_usermodehelper_exec(info, wait); +} + +/* + * Request userspace finish the construction of a key * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>" */ static int call_sbin_request_key(struct key_construction *cons, const char *op, void *aux) { - struct task_struct *tsk = current; + const struct cred *cred = current_cred(); key_serial_t prkey, sskey; - struct key *key = cons->key, *authkey = cons->authkey, *keyring; + struct key *key = cons->key, *authkey = cons->authkey, *keyring, + *session; char *argv[9], *envp[3], uid_str[12], gid_str[12]; char key_str[12], keyring_str[3][12]; char desc[20]; @@ -73,45 +124,50 @@ static int call_sbin_request_key(struct key_construction *cons, kenter("{%d},{%d},%s", key->serial, authkey->serial, op); + ret = install_user_keyrings(); + if (ret < 0) + goto error_alloc; + /* allocate a new session keyring */ sprintf(desc, "_req.%u", key->serial); - keyring = keyring_alloc(desc, current->fsuid, current->fsgid, current, + cred = get_current_cred(); + keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred, + KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ, KEY_ALLOC_QUOTA_OVERRUN, NULL); + put_cred(cred); if (IS_ERR(keyring)) { ret = PTR_ERR(keyring); goto error_alloc; } /* attach the auth key to the session keyring */ - ret = __key_link(keyring, authkey); + ret = key_link(keyring, authkey); if (ret < 0) goto error_link; /* record the UID and GID */ - sprintf(uid_str, "%d", current->fsuid); - sprintf(gid_str, "%d", current->fsgid); + sprintf(uid_str, "%d", from_kuid(&init_user_ns, cred->fsuid)); + sprintf(gid_str, "%d", from_kgid(&init_user_ns, cred->fsgid)); /* we say which key is under construction */ sprintf(key_str, "%d", key->serial); /* we specify the process's default keyrings */ sprintf(keyring_str[0], "%d", - tsk->thread_keyring ? tsk->thread_keyring->serial : 0); + cred->thread_keyring ? cred->thread_keyring->serial : 0); prkey = 0; - if (tsk->signal->process_keyring) - prkey = tsk->signal->process_keyring->serial; - + if (cred->process_keyring) + prkey = cred->process_keyring->serial; sprintf(keyring_str[1], "%d", prkey); - if (tsk->signal->session_keyring) { - rcu_read_lock(); - sskey = rcu_dereference(tsk->signal->session_keyring)->serial; - rcu_read_unlock(); - } else { - sskey = tsk->user->session_keyring->serial; - } + rcu_read_lock(); + session = rcu_dereference(cred->session_keyring); + if (!session) + session = cred->user->session_keyring; + sskey = session->serial; + rcu_read_unlock(); sprintf(keyring_str[2], "%d", sskey); @@ -152,30 +208,34 @@ error_link: key_put(keyring); error_alloc: - kleave(" = %d", ret); complete_request_key(cons, ret); + kleave(" = %d", ret); return ret; } /* - * call out to userspace for key construction - * - we ignore program failure and go on key status instead + * Call out to userspace for key construction. + * + * Program failure is ignored in favour of key status. */ -static int construct_key(struct key *key, const char *callout_info, void *aux) +static int construct_key(struct key *key, const void *callout_info, + size_t callout_len, void *aux, + struct key *dest_keyring) { struct key_construction *cons; request_key_actor_t actor; struct key *authkey; int ret; - kenter("%d,%s,%p", key->serial, callout_info, aux); + kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux); cons = kmalloc(sizeof(*cons), GFP_KERNEL); if (!cons) return -ENOMEM; /* allocate an authorisation key */ - authkey = request_key_auth_new(key, callout_info); + authkey = request_key_auth_new(key, callout_info, callout_len, + dest_keyring); if (IS_ERR(authkey)) { kfree(cons); ret = PTR_ERR(authkey); @@ -203,46 +263,68 @@ static int construct_key(struct key *key, const char *callout_info, void *aux) } /* - * link a key to the appropriate destination keyring - * - the caller must hold a write lock on the destination keyring + * Get the appropriate destination keyring for the request. + * + * The keyring selected is returned with an extra reference upon it which the + * caller must release. */ -static void construct_key_make_link(struct key *key, struct key *dest_keyring) +static void construct_get_dest_keyring(struct key **_dest_keyring) { - struct task_struct *tsk = current; - struct key *drop = NULL; + struct request_key_auth *rka; + const struct cred *cred = current_cred(); + struct key *dest_keyring = *_dest_keyring, *authkey; - kenter("{%d},%p", key->serial, dest_keyring); + kenter("%p", dest_keyring); /* find the appropriate keyring */ - if (!dest_keyring) { - switch (tsk->jit_keyring) { + if (dest_keyring) { + /* the caller supplied one */ + key_get(dest_keyring); + } else { + /* use a default keyring; falling through the cases until we + * find one that we actually have */ + switch (cred->jit_keyring) { case KEY_REQKEY_DEFL_DEFAULT: + case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: + if (cred->request_key_auth) { + authkey = cred->request_key_auth; + down_read(&authkey->sem); + rka = authkey->payload.data; + if (!test_bit(KEY_FLAG_REVOKED, + &authkey->flags)) + dest_keyring = + key_get(rka->dest_keyring); + up_read(&authkey->sem); + if (dest_keyring) + break; + } + case KEY_REQKEY_DEFL_THREAD_KEYRING: - dest_keyring = tsk->thread_keyring; + dest_keyring = key_get(cred->thread_keyring); if (dest_keyring) break; case KEY_REQKEY_DEFL_PROCESS_KEYRING: - dest_keyring = tsk->signal->process_keyring; + dest_keyring = key_get(cred->process_keyring); if (dest_keyring) break; case KEY_REQKEY_DEFL_SESSION_KEYRING: rcu_read_lock(); dest_keyring = key_get( - rcu_dereference(tsk->signal->session_keyring)); + rcu_dereference(cred->session_keyring)); rcu_read_unlock(); - drop = dest_keyring; if (dest_keyring) break; case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: - dest_keyring = tsk->user->session_keyring; + dest_keyring = + key_get(cred->user->session_keyring); break; case KEY_REQKEY_DEFL_USER_KEYRING: - dest_keyring = tsk->user->uid_keyring; + dest_keyring = key_get(cred->user->uid_keyring); break; case KEY_REQKEY_DEFL_GROUP_KEYRING: @@ -251,86 +333,120 @@ static void construct_key_make_link(struct key *key, struct key *dest_keyring) } } - /* and attach the key to it */ - __key_link(dest_keyring, key); - key_put(drop); - kleave(""); + *_dest_keyring = dest_keyring; + kleave(" [dk %d]", key_serial(dest_keyring)); + return; } /* - * allocate a new key in under-construction state and attempt to link it in to - * the requested place - * - may return a key that's already under construction instead + * Allocate a new key in under-construction state and attempt to link it in to + * the requested keyring. + * + * May return a key that's already under construction instead if there was a + * race between two thread calling request_key(). */ -static int construct_alloc_key(struct key_type *type, - const char *description, +static int construct_alloc_key(struct keyring_search_context *ctx, struct key *dest_keyring, unsigned long flags, struct key_user *user, struct key **_key) { + struct assoc_array_edit *edit; struct key *key; + key_perm_t perm; key_ref_t key_ref; + int ret; - kenter("%s,%s,,,", type->name, description); + kenter("%s,%s,,,", + ctx->index_key.type->name, ctx->index_key.description); + *_key = NULL; mutex_lock(&user->cons_lock); - key = key_alloc(type, description, - current->fsuid, current->fsgid, current, KEY_POS_ALL, - flags); + perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; + perm |= KEY_USR_VIEW; + if (ctx->index_key.type->read) + perm |= KEY_POS_READ; + if (ctx->index_key.type == &key_type_keyring || + ctx->index_key.type->update) + perm |= KEY_POS_WRITE; + + key = key_alloc(ctx->index_key.type, ctx->index_key.description, + ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred, + perm, flags); if (IS_ERR(key)) goto alloc_failed; set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags); - if (dest_keyring) - down_write(&dest_keyring->sem); + if (dest_keyring) { + ret = __key_link_begin(dest_keyring, &ctx->index_key, &edit); + if (ret < 0) + goto link_prealloc_failed; + } /* attach the key to the destination keyring under lock, but we do need * to do another check just in case someone beat us to it whilst we * waited for locks */ mutex_lock(&key_construction_mutex); - key_ref = search_process_keyrings(type, description, type->match, - current); + key_ref = search_process_keyrings(ctx); if (!IS_ERR(key_ref)) goto key_already_present; if (dest_keyring) - construct_key_make_link(key, dest_keyring); + __key_link(key, &edit); mutex_unlock(&key_construction_mutex); if (dest_keyring) - up_write(&dest_keyring->sem); + __key_link_end(dest_keyring, &ctx->index_key, edit); mutex_unlock(&user->cons_lock); *_key = key; kleave(" = 0 [%d]", key_serial(key)); return 0; + /* the key is now present - we tell the caller that we found it by + * returning -EINPROGRESS */ key_already_present: + key_put(key); mutex_unlock(&key_construction_mutex); - if (dest_keyring) - up_write(&dest_keyring->sem); + key = key_ref_to_ptr(key_ref); + if (dest_keyring) { + ret = __key_link_check_live_key(dest_keyring, key); + if (ret == 0) + __key_link(key, &edit); + __key_link_end(dest_keyring, &ctx->index_key, edit); + if (ret < 0) + goto link_check_failed; + } mutex_unlock(&user->cons_lock); - key_put(key); - *_key = key = key_ref_to_ptr(key_ref); + *_key = key; kleave(" = -EINPROGRESS [%d]", key_serial(key)); return -EINPROGRESS; +link_check_failed: + mutex_unlock(&user->cons_lock); + key_put(key); + kleave(" = %d [linkcheck]", ret); + return ret; + +link_prealloc_failed: + mutex_unlock(&user->cons_lock); + kleave(" = %d [prelink]", ret); + return ret; + alloc_failed: mutex_unlock(&user->cons_lock); - *_key = NULL; kleave(" = %ld", PTR_ERR(key)); return PTR_ERR(key); } /* - * commence key construction + * Commence key construction. */ -static struct key *construct_key_and_link(struct key_type *type, - const char *description, +static struct key *construct_key_and_link(struct keyring_search_context *ctx, const char *callout_info, + size_t callout_len, void *aux, struct key *dest_keyring, unsigned long flags) @@ -339,55 +455,109 @@ static struct key *construct_key_and_link(struct key_type *type, struct key *key; int ret; - user = key_user_lookup(current->fsuid); + kenter(""); + + user = key_user_lookup(current_fsuid()); if (!user) return ERR_PTR(-ENOMEM); - ret = construct_alloc_key(type, description, dest_keyring, flags, user, - &key); + construct_get_dest_keyring(&dest_keyring); + + ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key); key_user_put(user); if (ret == 0) { - ret = construct_key(key, callout_info, aux); - if (ret < 0) + ret = construct_key(key, callout_info, callout_len, aux, + dest_keyring); + if (ret < 0) { + kdebug("cons failed"); goto construction_failed; + } + } else if (ret == -EINPROGRESS) { + ret = 0; + } else { + goto couldnt_alloc_key; } + key_put(dest_keyring); + kleave(" = key %d", key_serial(key)); return key; construction_failed: key_negate_and_link(key, key_negative_timeout, NULL, NULL); key_put(key); +couldnt_alloc_key: + key_put(dest_keyring); + kleave(" = %d", ret); return ERR_PTR(ret); } -/* - * request a key - * - search the process's keyrings - * - check the list of keys being created or updated - * - call out to userspace for a key if supplementary info was provided - * - cache the key in an appropriate keyring +/** + * request_key_and_link - Request a key and cache it in a keyring. + * @type: The type of key we want. + * @description: The searchable description of the key. + * @callout_info: The data to pass to the instantiation upcall (or NULL). + * @callout_len: The length of callout_info. + * @aux: Auxiliary data for the upcall. + * @dest_keyring: Where to cache the key. + * @flags: Flags to key_alloc(). + * + * A key matching the specified criteria is searched for in the process's + * keyrings and returned with its usage count incremented if found. Otherwise, + * if callout_info is not NULL, a key will be allocated and some service + * (probably in userspace) will be asked to instantiate it. + * + * If successfully found or created, the key will be linked to the destination + * keyring if one is provided. + * + * Returns a pointer to the key if successful; -EACCES, -ENOKEY, -EKEYREVOKED + * or -EKEYEXPIRED if an inaccessible, negative, revoked or expired key was + * found; -ENOKEY if no key was found and no @callout_info was given; -EDQUOT + * if insufficient key quota was available to create a new key; or -ENOMEM if + * insufficient memory was available. + * + * If the returned key was created, then it may still be under construction, + * and wait_for_key_construction() should be used to wait for that to complete. */ struct key *request_key_and_link(struct key_type *type, const char *description, - const char *callout_info, + const void *callout_info, + size_t callout_len, void *aux, struct key *dest_keyring, unsigned long flags) { + struct keyring_search_context ctx = { + .index_key.type = type, + .index_key.description = description, + .cred = current_cred(), + .match = type->match, + .match_data = description, + .flags = KEYRING_SEARCH_LOOKUP_DIRECT, + }; struct key *key; key_ref_t key_ref; + int ret; - kenter("%s,%s,%s,%p,%p,%lx", - type->name, description, callout_info, aux, - dest_keyring, flags); + kenter("%s,%s,%p,%zu,%p,%p,%lx", + ctx.index_key.type->name, ctx.index_key.description, + callout_info, callout_len, aux, dest_keyring, flags); /* search all the process keyrings for a key */ - key_ref = search_process_keyrings(type, description, type->match, - current); + key_ref = search_process_keyrings(&ctx); if (!IS_ERR(key_ref)) { key = key_ref_to_ptr(key_ref); + if (dest_keyring) { + construct_get_dest_keyring(&dest_keyring); + ret = key_link(dest_keyring, key); + key_put(dest_keyring); + if (ret < 0) { + key_put(key); + key = ERR_PTR(ret); + goto error; + } + } } else if (PTR_ERR(key_ref) != -EAGAIN) { key = ERR_CAST(key_ref); } else { @@ -397,7 +567,7 @@ struct key *request_key_and_link(struct key_type *type, if (!callout_info) goto error; - key = construct_key_and_link(type, description, callout_info, + key = construct_key_and_link(&ctx, callout_info, callout_len, aux, dest_keyring, flags); } @@ -406,8 +576,16 @@ error: return key; } -/* - * wait for construction of a key to complete +/** + * wait_for_key_construction - Wait for construction of a key to complete + * @key: The key being waited for. + * @intr: Whether to wait interruptibly. + * + * Wait for a key to finish being constructed. + * + * Returns 0 if successful; -ERESTARTSYS if the wait was interrupted; -ENOKEY + * if the key was negated; or -EKEYREVOKED or -EKEYEXPIRED if the key was + * revoked or expired. */ int wait_for_key_construction(struct key *key, bool intr) { @@ -418,26 +596,40 @@ int wait_for_key_construction(struct key *key, bool intr) intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE); if (ret < 0) return ret; + if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) { + smp_rmb(); + return key->type_data.reject_error; + } return key_validate(key); } EXPORT_SYMBOL(wait_for_key_construction); -/* - * request a key - * - search the process's keyrings - * - check the list of keys being created or updated - * - call out to userspace for a key if supplementary info was provided - * - waits uninterruptible for creation to complete +/** + * request_key - Request a key and wait for construction + * @type: Type of key. + * @description: The searchable description of the key. + * @callout_info: The data to pass to the instantiation upcall (or NULL). + * + * As for request_key_and_link() except that it does not add the returned key + * to a keyring if found, new keys are always allocated in the user's quota, + * the callout_info must be a NUL-terminated string and no auxiliary data can + * be passed. + * + * Furthermore, it then works as wait_for_key_construction() to wait for the + * completion of keys undergoing construction with a non-interruptible wait. */ struct key *request_key(struct key_type *type, const char *description, const char *callout_info) { struct key *key; + size_t callout_len = 0; int ret; - key = request_key_and_link(type, description, callout_info, NULL, - NULL, KEY_ALLOC_IN_QUOTA); + if (callout_info) + callout_len = strlen(callout_info); + key = request_key_and_link(type, description, callout_info, callout_len, + NULL, NULL, KEY_ALLOC_IN_QUOTA); if (!IS_ERR(key)) { ret = wait_for_key_construction(key, false); if (ret < 0) { @@ -449,23 +641,31 @@ struct key *request_key(struct key_type *type, } EXPORT_SYMBOL(request_key); -/* - * request a key with auxiliary data for the upcaller - * - search the process's keyrings - * - check the list of keys being created or updated - * - call out to userspace for a key if supplementary info was provided - * - waits uninterruptible for creation to complete +/** + * request_key_with_auxdata - Request a key with auxiliary data for the upcaller + * @type: The type of key we want. + * @description: The searchable description of the key. + * @callout_info: The data to pass to the instantiation upcall (or NULL). + * @callout_len: The length of callout_info. + * @aux: Auxiliary data for the upcall. + * + * As for request_key_and_link() except that it does not add the returned key + * to a keyring if found and new keys are always allocated in the user's quota. + * + * Furthermore, it then works as wait_for_key_construction() to wait for the + * completion of keys undergoing construction with a non-interruptible wait. */ struct key *request_key_with_auxdata(struct key_type *type, const char *description, - const char *callout_info, + const void *callout_info, + size_t callout_len, void *aux) { struct key *key; int ret; - key = request_key_and_link(type, description, callout_info, aux, - NULL, KEY_ALLOC_IN_QUOTA); + key = request_key_and_link(type, description, callout_info, callout_len, + aux, NULL, KEY_ALLOC_IN_QUOTA); if (!IS_ERR(key)) { ret = wait_for_key_construction(key, false); if (ret < 0) { @@ -478,32 +678,51 @@ struct key *request_key_with_auxdata(struct key_type *type, EXPORT_SYMBOL(request_key_with_auxdata); /* - * request a key (allow async construction) - * - search the process's keyrings - * - check the list of keys being created or updated - * - call out to userspace for a key if supplementary info was provided + * request_key_async - Request a key (allow async construction) + * @type: Type of key. + * @description: The searchable description of the key. + * @callout_info: The data to pass to the instantiation upcall (or NULL). + * @callout_len: The length of callout_info. + * + * As for request_key_and_link() except that it does not add the returned key + * to a keyring if found, new keys are always allocated in the user's quota and + * no auxiliary data can be passed. + * + * The caller should call wait_for_key_construction() to wait for the + * completion of the returned key if it is still undergoing construction. */ struct key *request_key_async(struct key_type *type, const char *description, - const char *callout_info) + const void *callout_info, + size_t callout_len) { - return request_key_and_link(type, description, callout_info, NULL, - NULL, KEY_ALLOC_IN_QUOTA); + return request_key_and_link(type, description, callout_info, + callout_len, NULL, NULL, + KEY_ALLOC_IN_QUOTA); } EXPORT_SYMBOL(request_key_async); /* * request a key with auxiliary data for the upcaller (allow async construction) - * - search the process's keyrings - * - check the list of keys being created or updated - * - call out to userspace for a key if supplementary info was provided + * @type: Type of key. + * @description: The searchable description of the key. + * @callout_info: The data to pass to the instantiation upcall (or NULL). + * @callout_len: The length of callout_info. + * @aux: Auxiliary data for the upcall. + * + * As for request_key_and_link() except that it does not add the returned key + * to a keyring if found and new keys are always allocated in the user's quota. + * + * The caller should call wait_for_key_construction() to wait for the + * completion of the returned key if it is still undergoing construction. */ struct key *request_key_async_with_auxdata(struct key_type *type, const char *description, - const char *callout_info, + const void *callout_info, + size_t callout_len, void *aux) { - return request_key_and_link(type, description, callout_info, aux, - NULL, KEY_ALLOC_IN_QUOTA); + return request_key_and_link(type, description, callout_info, + callout_len, aux, NULL, KEY_ALLOC_IN_QUOTA); } EXPORT_SYMBOL(request_key_async_with_auxdata); diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c index e42b5252486..7495a93b4b9 100644 --- a/security/keys/request_key_auth.c +++ b/security/keys/request_key_auth.c @@ -1,4 +1,4 @@ -/* request_key_auth.c: request key authorisation controlling key def +/* Request key authorisation token key definition. * * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) @@ -8,24 +8,27 @@ * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * - * See Documentation/keys-request-key.txt + * See Documentation/security/keys-request-key.txt */ #include <linux/module.h> #include <linux/sched.h> #include <linux/err.h> #include <linux/seq_file.h> +#include <linux/slab.h> #include <asm/uaccess.h> #include "internal.h" +#include <keys/user-type.h> -static int request_key_auth_instantiate(struct key *, const void *, size_t); +static int request_key_auth_instantiate(struct key *, + struct key_preparsed_payload *); static void request_key_auth_describe(const struct key *, struct seq_file *); static void request_key_auth_revoke(struct key *); static void request_key_auth_destroy(struct key *); static long request_key_auth_read(const struct key *, char __user *, size_t); /* - * the request-key authorisation key type definition + * The request-key authorisation key type definition. */ struct key_type key_type_request_key_auth = { .name = ".request_key_auth", @@ -37,22 +40,18 @@ struct key_type key_type_request_key_auth = { .read = request_key_auth_read, }; -/*****************************************************************************/ /* - * instantiate a request-key authorisation key + * Instantiate a request-key authorisation key. */ static int request_key_auth_instantiate(struct key *key, - const void *data, - size_t datalen) + struct key_preparsed_payload *prep) { - key->payload.data = (struct request_key_auth *) data; + key->payload.data = (struct request_key_auth *)prep->data; return 0; +} -} /* end request_key_auth_instantiate() */ - -/*****************************************************************************/ /* - * reading a request-key authorisation key retrieves the callout information + * Describe an authorisation token. */ static void request_key_auth_describe(const struct key *key, struct seq_file *m) @@ -61,13 +60,12 @@ static void request_key_auth_describe(const struct key *key, seq_puts(m, "key:"); seq_puts(m, key->description); - seq_printf(m, " pid:%d ci:%zu", rka->pid, strlen(rka->callout_info)); - -} /* end request_key_auth_describe() */ + if (key_is_instantiated(key)) + seq_printf(m, " pid:%d ci:%zu", rka->pid, rka->callout_len); +} -/*****************************************************************************/ /* - * read the callout_info data + * Read the callout_info data (retrieves the callout information). * - the key's semaphore is read-locked */ static long request_key_auth_read(const struct key *key, @@ -77,7 +75,7 @@ static long request_key_auth_read(const struct key *key, size_t datalen; long ret; - datalen = strlen(rka->callout_info); + datalen = rka->callout_len; ret = datalen; /* we can return the data as is */ @@ -90,13 +88,12 @@ static long request_key_auth_read(const struct key *key, } return ret; +} -} /* end request_key_auth_read() */ - -/*****************************************************************************/ /* - * handle revocation of an authorisation token key - * - called with the key sem write-locked + * Handle revocation of an authorisation token key. + * + * Called with the key sem write-locked. */ static void request_key_auth_revoke(struct key *key) { @@ -104,16 +101,14 @@ static void request_key_auth_revoke(struct key *key) kenter("{%d}", key->serial); - if (rka->context) { - put_task_struct(rka->context); - rka->context = NULL; + if (rka->cred) { + put_cred(rka->cred); + rka->cred = NULL; } +} -} /* end request_key_auth_revoke() */ - -/*****************************************************************************/ /* - * destroy an instantiation authorisation token key + * Destroy an instantiation authorisation token key. */ static void request_key_auth_destroy(struct key *key) { @@ -121,25 +116,26 @@ static void request_key_auth_destroy(struct key *key) kenter("{%d}", key->serial); - if (rka->context) { - put_task_struct(rka->context); - rka->context = NULL; + if (rka->cred) { + put_cred(rka->cred); + rka->cred = NULL; } key_put(rka->target_key); + key_put(rka->dest_keyring); kfree(rka->callout_info); kfree(rka); +} -} /* end request_key_auth_destroy() */ - -/*****************************************************************************/ /* - * create an authorisation token for /sbin/request-key or whoever to gain - * access to the caller's security data + * Create an authorisation token for /sbin/request-key or whoever to gain + * access to the caller's security data. */ -struct key *request_key_auth_new(struct key *target, const char *callout_info) +struct key *request_key_auth_new(struct key *target, const void *callout_info, + size_t callout_len, struct key *dest_keyring) { struct request_key_auth *rka, *irka; + const struct cred *cred = current->cred; struct key *authkey = NULL; char desc[20]; int ret; @@ -152,7 +148,7 @@ struct key *request_key_auth_new(struct key *target, const char *callout_info) kleave(" = -ENOMEM"); return ERR_PTR(-ENOMEM); } - rka->callout_info = kmalloc(strlen(callout_info) + 1, GFP_KERNEL); + rka->callout_info = kmalloc(callout_len, GFP_KERNEL); if (!rka->callout_info) { kleave(" = -ENOMEM"); kfree(rka); @@ -161,38 +157,37 @@ struct key *request_key_auth_new(struct key *target, const char *callout_info) /* see if the calling process is already servicing the key request of * another process */ - if (current->request_key_auth) { + if (cred->request_key_auth) { /* it is - use that instantiation context here too */ - down_read(¤t->request_key_auth->sem); + down_read(&cred->request_key_auth->sem); /* if the auth key has been revoked, then the key we're * servicing is already instantiated */ - if (test_bit(KEY_FLAG_REVOKED, - ¤t->request_key_auth->flags)) + if (test_bit(KEY_FLAG_REVOKED, &cred->request_key_auth->flags)) goto auth_key_revoked; - irka = current->request_key_auth->payload.data; - rka->context = irka->context; + irka = cred->request_key_auth->payload.data; + rka->cred = get_cred(irka->cred); rka->pid = irka->pid; - get_task_struct(rka->context); - up_read(¤t->request_key_auth->sem); + up_read(&cred->request_key_auth->sem); } else { /* it isn't - use this process as the context */ - rka->context = current; + rka->cred = get_cred(cred); rka->pid = current->pid; - get_task_struct(rka->context); } rka->target_key = key_get(target); - strcpy(rka->callout_info, callout_info); + rka->dest_keyring = key_get(dest_keyring); + memcpy(rka->callout_info, callout_info, callout_len); + rka->callout_len = callout_len; /* allocate the auth key */ sprintf(desc, "%x", target->serial); authkey = key_alloc(&key_type_request_key_auth, desc, - current->fsuid, current->fsgid, current, + cred->fsuid, cred->fsgid, cred, KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH | KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA); if (IS_ERR(authkey)) { @@ -200,16 +195,16 @@ struct key *request_key_auth_new(struct key *target, const char *callout_info) goto error_alloc; } - /* construct and attach to the keyring */ + /* construct the auth key */ ret = key_instantiate_and_link(authkey, rka, 0, NULL, NULL); if (ret < 0) goto error_inst; - kleave(" = {%d}", authkey->serial); + kleave(" = {%d,%d}", authkey->serial, atomic_read(&authkey->usage)); return authkey; auth_key_revoked: - up_read(¤t->request_key_auth->sem); + up_read(&cred->request_key_auth->sem); kfree(rka->callout_info); kfree(rka); kleave("= -EKEYREVOKED"); @@ -220,48 +215,39 @@ error_inst: key_put(authkey); error_alloc: key_put(rka->target_key); + key_put(rka->dest_keyring); kfree(rka->callout_info); kfree(rka); kleave("= %d", ret); return ERR_PTR(ret); +} -} /* end request_key_auth_new() */ - -/*****************************************************************************/ -/* - * see if an authorisation key is associated with a particular key - */ -static int key_get_instantiation_authkey_match(const struct key *key, - const void *_id) -{ - struct request_key_auth *rka = key->payload.data; - key_serial_t id = (key_serial_t)(unsigned long) _id; - - return rka->target_key->serial == id; - -} /* end key_get_instantiation_authkey_match() */ - -/*****************************************************************************/ /* - * get the authorisation key for instantiation of a specific key if attached to - * the current process's keyrings - * - this key is inserted into a keyring and that is set as /sbin/request-key's - * session keyring - * - a target_id of zero specifies any valid token + * Search the current process's keyrings for the authorisation key for + * instantiation of a key. */ struct key *key_get_instantiation_authkey(key_serial_t target_id) { + char description[16]; + struct keyring_search_context ctx = { + .index_key.type = &key_type_request_key_auth, + .index_key.description = description, + .cred = current_cred(), + .match = user_match, + .match_data = description, + .flags = KEYRING_SEARCH_LOOKUP_DIRECT, + }; struct key *authkey; key_ref_t authkey_ref; - authkey_ref = search_process_keyrings( - &key_type_request_key_auth, - (void *) (unsigned long) target_id, - key_get_instantiation_authkey_match, - current); + sprintf(description, "%x", target_id); + + authkey_ref = search_process_keyrings(&ctx); if (IS_ERR(authkey_ref)) { authkey = ERR_CAST(authkey_ref); + if (authkey == ERR_PTR(-EAGAIN)) + authkey = ERR_PTR(-ENOKEY); goto error; } @@ -273,5 +259,4 @@ struct key *key_get_instantiation_authkey(key_serial_t target_id) error: return authkey; - -} /* end key_get_instantiation_authkey() */ +} diff --git a/security/keys/sysctl.c b/security/keys/sysctl.c new file mode 100644 index 00000000000..b68faa1a5cf --- /dev/null +++ b/security/keys/sysctl.c @@ -0,0 +1,76 @@ +/* Key management controls + * + * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include <linux/key.h> +#include <linux/sysctl.h> +#include "internal.h" + +static const int zero, one = 1, max = INT_MAX; + +struct ctl_table key_sysctls[] = { + { + .procname = "maxkeys", + .data = &key_quota_maxkeys, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *) &one, + .extra2 = (void *) &max, + }, + { + .procname = "maxbytes", + .data = &key_quota_maxbytes, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *) &one, + .extra2 = (void *) &max, + }, + { + .procname = "root_maxkeys", + .data = &key_quota_root_maxkeys, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *) &one, + .extra2 = (void *) &max, + }, + { + .procname = "root_maxbytes", + .data = &key_quota_root_maxbytes, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *) &one, + .extra2 = (void *) &max, + }, + { + .procname = "gc_delay", + .data = &key_gc_delay, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *) &zero, + .extra2 = (void *) &max, + }, +#ifdef CONFIG_PERSISTENT_KEYRINGS + { + .procname = "persistent_keyring_expiry", + .data = &persistent_keyring_expiry, + .maxlen = sizeof(unsigned), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *) &zero, + .extra2 = (void *) &max, + }, +#endif + { } +}; diff --git a/security/keys/trusted.c b/security/keys/trusted.c new file mode 100644 index 00000000000..6b804aa4529 --- /dev/null +++ b/security/keys/trusted.c @@ -0,0 +1,1163 @@ +/* + * Copyright (C) 2010 IBM Corporation + * + * Author: + * David Safford <safford@us.ibm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2 of the License. + * + * See Documentation/security/keys-trusted-encrypted.txt + */ + +#include <linux/uaccess.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/parser.h> +#include <linux/string.h> +#include <linux/err.h> +#include <keys/user-type.h> +#include <keys/trusted-type.h> +#include <linux/key-type.h> +#include <linux/rcupdate.h> +#include <linux/crypto.h> +#include <crypto/hash.h> +#include <crypto/sha.h> +#include <linux/capability.h> +#include <linux/tpm.h> +#include <linux/tpm_command.h> + +#include "trusted.h" + +static const char hmac_alg[] = "hmac(sha1)"; +static const char hash_alg[] = "sha1"; + +struct sdesc { + struct shash_desc shash; + char ctx[]; +}; + +static struct crypto_shash *hashalg; +static struct crypto_shash *hmacalg; + +static struct sdesc *init_sdesc(struct crypto_shash *alg) +{ + struct sdesc *sdesc; + int size; + + size = sizeof(struct shash_desc) + crypto_shash_descsize(alg); + sdesc = kmalloc(size, GFP_KERNEL); + if (!sdesc) + return ERR_PTR(-ENOMEM); + sdesc->shash.tfm = alg; + sdesc->shash.flags = 0x0; + return sdesc; +} + +static int TSS_sha1(const unsigned char *data, unsigned int datalen, + unsigned char *digest) +{ + struct sdesc *sdesc; + int ret; + + sdesc = init_sdesc(hashalg); + if (IS_ERR(sdesc)) { + pr_info("trusted_key: can't alloc %s\n", hash_alg); + return PTR_ERR(sdesc); + } + + ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest); + kfree(sdesc); + return ret; +} + +static int TSS_rawhmac(unsigned char *digest, const unsigned char *key, + unsigned int keylen, ...) +{ + struct sdesc *sdesc; + va_list argp; + unsigned int dlen; + unsigned char *data; + int ret; + + sdesc = init_sdesc(hmacalg); + if (IS_ERR(sdesc)) { + pr_info("trusted_key: can't alloc %s\n", hmac_alg); + return PTR_ERR(sdesc); + } + + ret = crypto_shash_setkey(hmacalg, key, keylen); + if (ret < 0) + goto out; + ret = crypto_shash_init(&sdesc->shash); + if (ret < 0) + goto out; + + va_start(argp, keylen); + for (;;) { + dlen = va_arg(argp, unsigned int); + if (dlen == 0) + break; + data = va_arg(argp, unsigned char *); + if (data == NULL) { + ret = -EINVAL; + break; + } + ret = crypto_shash_update(&sdesc->shash, data, dlen); + if (ret < 0) + break; + } + va_end(argp); + if (!ret) + ret = crypto_shash_final(&sdesc->shash, digest); +out: + kfree(sdesc); + return ret; +} + +/* + * calculate authorization info fields to send to TPM + */ +static int TSS_authhmac(unsigned char *digest, const unsigned char *key, + unsigned int keylen, unsigned char *h1, + unsigned char *h2, unsigned char h3, ...) +{ + unsigned char paramdigest[SHA1_DIGEST_SIZE]; + struct sdesc *sdesc; + unsigned int dlen; + unsigned char *data; + unsigned char c; + int ret; + va_list argp; + + sdesc = init_sdesc(hashalg); + if (IS_ERR(sdesc)) { + pr_info("trusted_key: can't alloc %s\n", hash_alg); + return PTR_ERR(sdesc); + } + + c = h3; + ret = crypto_shash_init(&sdesc->shash); + if (ret < 0) + goto out; + va_start(argp, h3); + for (;;) { + dlen = va_arg(argp, unsigned int); + if (dlen == 0) + break; + data = va_arg(argp, unsigned char *); + if (!data) { + ret = -EINVAL; + break; + } + ret = crypto_shash_update(&sdesc->shash, data, dlen); + if (ret < 0) + break; + } + va_end(argp); + if (!ret) + ret = crypto_shash_final(&sdesc->shash, paramdigest); + if (!ret) + ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE, + paramdigest, TPM_NONCE_SIZE, h1, + TPM_NONCE_SIZE, h2, 1, &c, 0, 0); +out: + kfree(sdesc); + return ret; +} + +/* + * verify the AUTH1_COMMAND (Seal) result from TPM + */ +static int TSS_checkhmac1(unsigned char *buffer, + const uint32_t command, + const unsigned char *ononce, + const unsigned char *key, + unsigned int keylen, ...) +{ + uint32_t bufsize; + uint16_t tag; + uint32_t ordinal; + uint32_t result; + unsigned char *enonce; + unsigned char *continueflag; + unsigned char *authdata; + unsigned char testhmac[SHA1_DIGEST_SIZE]; + unsigned char paramdigest[SHA1_DIGEST_SIZE]; + struct sdesc *sdesc; + unsigned int dlen; + unsigned int dpos; + va_list argp; + int ret; + + bufsize = LOAD32(buffer, TPM_SIZE_OFFSET); + tag = LOAD16(buffer, 0); + ordinal = command; + result = LOAD32N(buffer, TPM_RETURN_OFFSET); + if (tag == TPM_TAG_RSP_COMMAND) + return 0; + if (tag != TPM_TAG_RSP_AUTH1_COMMAND) + return -EINVAL; + authdata = buffer + bufsize - SHA1_DIGEST_SIZE; + continueflag = authdata - 1; + enonce = continueflag - TPM_NONCE_SIZE; + + sdesc = init_sdesc(hashalg); + if (IS_ERR(sdesc)) { + pr_info("trusted_key: can't alloc %s\n", hash_alg); + return PTR_ERR(sdesc); + } + ret = crypto_shash_init(&sdesc->shash); + if (ret < 0) + goto out; + ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result, + sizeof result); + if (ret < 0) + goto out; + ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal, + sizeof ordinal); + if (ret < 0) + goto out; + va_start(argp, keylen); + for (;;) { + dlen = va_arg(argp, unsigned int); + if (dlen == 0) + break; + dpos = va_arg(argp, unsigned int); + ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen); + if (ret < 0) + break; + } + va_end(argp); + if (!ret) + ret = crypto_shash_final(&sdesc->shash, paramdigest); + if (ret < 0) + goto out; + + ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest, + TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce, + 1, continueflag, 0, 0); + if (ret < 0) + goto out; + + if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE)) + ret = -EINVAL; +out: + kfree(sdesc); + return ret; +} + +/* + * verify the AUTH2_COMMAND (unseal) result from TPM + */ +static int TSS_checkhmac2(unsigned char *buffer, + const uint32_t command, + const unsigned char *ononce, + const unsigned char *key1, + unsigned int keylen1, + const unsigned char *key2, + unsigned int keylen2, ...) +{ + uint32_t bufsize; + uint16_t tag; + uint32_t ordinal; + uint32_t result; + unsigned char *enonce1; + unsigned char *continueflag1; + unsigned char *authdata1; + unsigned char *enonce2; + unsigned char *continueflag2; + unsigned char *authdata2; + unsigned char testhmac1[SHA1_DIGEST_SIZE]; + unsigned char testhmac2[SHA1_DIGEST_SIZE]; + unsigned char paramdigest[SHA1_DIGEST_SIZE]; + struct sdesc *sdesc; + unsigned int dlen; + unsigned int dpos; + va_list argp; + int ret; + + bufsize = LOAD32(buffer, TPM_SIZE_OFFSET); + tag = LOAD16(buffer, 0); + ordinal = command; + result = LOAD32N(buffer, TPM_RETURN_OFFSET); + + if (tag == TPM_TAG_RSP_COMMAND) + return 0; + if (tag != TPM_TAG_RSP_AUTH2_COMMAND) + return -EINVAL; + authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1 + + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE); + authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE); + continueflag1 = authdata1 - 1; + continueflag2 = authdata2 - 1; + enonce1 = continueflag1 - TPM_NONCE_SIZE; + enonce2 = continueflag2 - TPM_NONCE_SIZE; + + sdesc = init_sdesc(hashalg); + if (IS_ERR(sdesc)) { + pr_info("trusted_key: can't alloc %s\n", hash_alg); + return PTR_ERR(sdesc); + } + ret = crypto_shash_init(&sdesc->shash); + if (ret < 0) + goto out; + ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result, + sizeof result); + if (ret < 0) + goto out; + ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal, + sizeof ordinal); + if (ret < 0) + goto out; + + va_start(argp, keylen2); + for (;;) { + dlen = va_arg(argp, unsigned int); + if (dlen == 0) + break; + dpos = va_arg(argp, unsigned int); + ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen); + if (ret < 0) + break; + } + va_end(argp); + if (!ret) + ret = crypto_shash_final(&sdesc->shash, paramdigest); + if (ret < 0) + goto out; + + ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE, + paramdigest, TPM_NONCE_SIZE, enonce1, + TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0); + if (ret < 0) + goto out; + if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) { + ret = -EINVAL; + goto out; + } + ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE, + paramdigest, TPM_NONCE_SIZE, enonce2, + TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0); + if (ret < 0) + goto out; + if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE)) + ret = -EINVAL; +out: + kfree(sdesc); + return ret; +} + +/* + * For key specific tpm requests, we will generate and send our + * own TPM command packets using the drivers send function. + */ +static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd, + size_t buflen) +{ + int rc; + + dump_tpm_buf(cmd); + rc = tpm_send(chip_num, cmd, buflen); + dump_tpm_buf(cmd); + if (rc > 0) + /* Can't return positive return codes values to keyctl */ + rc = -EPERM; + return rc; +} + +/* + * Lock a trusted key, by extending a selected PCR. + * + * Prevents a trusted key that is sealed to PCRs from being accessed. + * This uses the tpm driver's extend function. + */ +static int pcrlock(const int pcrnum) +{ + unsigned char hash[SHA1_DIGEST_SIZE]; + int ret; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + ret = tpm_get_random(TPM_ANY_NUM, hash, SHA1_DIGEST_SIZE); + if (ret != SHA1_DIGEST_SIZE) + return ret; + return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0; +} + +/* + * Create an object specific authorisation protocol (OSAP) session + */ +static int osap(struct tpm_buf *tb, struct osapsess *s, + const unsigned char *key, uint16_t type, uint32_t handle) +{ + unsigned char enonce[TPM_NONCE_SIZE]; + unsigned char ononce[TPM_NONCE_SIZE]; + int ret; + + ret = tpm_get_random(TPM_ANY_NUM, ononce, TPM_NONCE_SIZE); + if (ret != TPM_NONCE_SIZE) + return ret; + + INIT_BUF(tb); + store16(tb, TPM_TAG_RQU_COMMAND); + store32(tb, TPM_OSAP_SIZE); + store32(tb, TPM_ORD_OSAP); + store16(tb, type); + store32(tb, handle); + storebytes(tb, ononce, TPM_NONCE_SIZE); + + ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); + if (ret < 0) + return ret; + + s->handle = LOAD32(tb->data, TPM_DATA_OFFSET); + memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]), + TPM_NONCE_SIZE); + memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) + + TPM_NONCE_SIZE]), TPM_NONCE_SIZE); + return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE, + enonce, TPM_NONCE_SIZE, ononce, 0, 0); +} + +/* + * Create an object independent authorisation protocol (oiap) session + */ +static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce) +{ + int ret; + + INIT_BUF(tb); + store16(tb, TPM_TAG_RQU_COMMAND); + store32(tb, TPM_OIAP_SIZE); + store32(tb, TPM_ORD_OIAP); + ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); + if (ret < 0) + return ret; + + *handle = LOAD32(tb->data, TPM_DATA_OFFSET); + memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)], + TPM_NONCE_SIZE); + return 0; +} + +struct tpm_digests { + unsigned char encauth[SHA1_DIGEST_SIZE]; + unsigned char pubauth[SHA1_DIGEST_SIZE]; + unsigned char xorwork[SHA1_DIGEST_SIZE * 2]; + unsigned char xorhash[SHA1_DIGEST_SIZE]; + unsigned char nonceodd[TPM_NONCE_SIZE]; +}; + +/* + * Have the TPM seal(encrypt) the trusted key, possibly based on + * Platform Configuration Registers (PCRs). AUTH1 for sealing key. + */ +static int tpm_seal(struct tpm_buf *tb, uint16_t keytype, + uint32_t keyhandle, const unsigned char *keyauth, + const unsigned char *data, uint32_t datalen, + unsigned char *blob, uint32_t *bloblen, + const unsigned char *blobauth, + const unsigned char *pcrinfo, uint32_t pcrinfosize) +{ + struct osapsess sess; + struct tpm_digests *td; + unsigned char cont; + uint32_t ordinal; + uint32_t pcrsize; + uint32_t datsize; + int sealinfosize; + int encdatasize; + int storedsize; + int ret; + int i; + + /* alloc some work space for all the hashes */ + td = kmalloc(sizeof *td, GFP_KERNEL); + if (!td) + return -ENOMEM; + + /* get session for sealing key */ + ret = osap(tb, &sess, keyauth, keytype, keyhandle); + if (ret < 0) + goto out; + dump_sess(&sess); + + /* calculate encrypted authorization value */ + memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE); + memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE); + ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash); + if (ret < 0) + goto out; + + ret = tpm_get_random(TPM_ANY_NUM, td->nonceodd, TPM_NONCE_SIZE); + if (ret != TPM_NONCE_SIZE) + goto out; + ordinal = htonl(TPM_ORD_SEAL); + datsize = htonl(datalen); + pcrsize = htonl(pcrinfosize); + cont = 0; + + /* encrypt data authorization key */ + for (i = 0; i < SHA1_DIGEST_SIZE; ++i) + td->encauth[i] = td->xorhash[i] ^ blobauth[i]; + + /* calculate authorization HMAC value */ + if (pcrinfosize == 0) { + /* no pcr info specified */ + ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, + sess.enonce, td->nonceodd, cont, + sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, + td->encauth, sizeof(uint32_t), &pcrsize, + sizeof(uint32_t), &datsize, datalen, data, 0, + 0); + } else { + /* pcr info specified */ + ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, + sess.enonce, td->nonceodd, cont, + sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, + td->encauth, sizeof(uint32_t), &pcrsize, + pcrinfosize, pcrinfo, sizeof(uint32_t), + &datsize, datalen, data, 0, 0); + } + if (ret < 0) + goto out; + + /* build and send the TPM request packet */ + INIT_BUF(tb); + store16(tb, TPM_TAG_RQU_AUTH1_COMMAND); + store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen); + store32(tb, TPM_ORD_SEAL); + store32(tb, keyhandle); + storebytes(tb, td->encauth, SHA1_DIGEST_SIZE); + store32(tb, pcrinfosize); + storebytes(tb, pcrinfo, pcrinfosize); + store32(tb, datalen); + storebytes(tb, data, datalen); + store32(tb, sess.handle); + storebytes(tb, td->nonceodd, TPM_NONCE_SIZE); + store8(tb, cont); + storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE); + + ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); + if (ret < 0) + goto out; + + /* calculate the size of the returned Blob */ + sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t)); + encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) + + sizeof(uint32_t) + sealinfosize); + storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize + + sizeof(uint32_t) + encdatasize; + + /* check the HMAC in the response */ + ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret, + SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0, + 0); + + /* copy the returned blob to caller */ + if (!ret) { + memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize); + *bloblen = storedsize; + } +out: + kfree(td); + return ret; +} + +/* + * use the AUTH2_COMMAND form of unseal, to authorize both key and blob + */ +static int tpm_unseal(struct tpm_buf *tb, + uint32_t keyhandle, const unsigned char *keyauth, + const unsigned char *blob, int bloblen, + const unsigned char *blobauth, + unsigned char *data, unsigned int *datalen) +{ + unsigned char nonceodd[TPM_NONCE_SIZE]; + unsigned char enonce1[TPM_NONCE_SIZE]; + unsigned char enonce2[TPM_NONCE_SIZE]; + unsigned char authdata1[SHA1_DIGEST_SIZE]; + unsigned char authdata2[SHA1_DIGEST_SIZE]; + uint32_t authhandle1 = 0; + uint32_t authhandle2 = 0; + unsigned char cont = 0; + uint32_t ordinal; + uint32_t keyhndl; + int ret; + + /* sessions for unsealing key and data */ + ret = oiap(tb, &authhandle1, enonce1); + if (ret < 0) { + pr_info("trusted_key: oiap failed (%d)\n", ret); + return ret; + } + ret = oiap(tb, &authhandle2, enonce2); + if (ret < 0) { + pr_info("trusted_key: oiap failed (%d)\n", ret); + return ret; + } + + ordinal = htonl(TPM_ORD_UNSEAL); + keyhndl = htonl(SRKHANDLE); + ret = tpm_get_random(TPM_ANY_NUM, nonceodd, TPM_NONCE_SIZE); + if (ret != TPM_NONCE_SIZE) { + pr_info("trusted_key: tpm_get_random failed (%d)\n", ret); + return ret; + } + ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE, + enonce1, nonceodd, cont, sizeof(uint32_t), + &ordinal, bloblen, blob, 0, 0); + if (ret < 0) + return ret; + ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE, + enonce2, nonceodd, cont, sizeof(uint32_t), + &ordinal, bloblen, blob, 0, 0); + if (ret < 0) + return ret; + + /* build and send TPM request packet */ + INIT_BUF(tb); + store16(tb, TPM_TAG_RQU_AUTH2_COMMAND); + store32(tb, TPM_UNSEAL_SIZE + bloblen); + store32(tb, TPM_ORD_UNSEAL); + store32(tb, keyhandle); + storebytes(tb, blob, bloblen); + store32(tb, authhandle1); + storebytes(tb, nonceodd, TPM_NONCE_SIZE); + store8(tb, cont); + storebytes(tb, authdata1, SHA1_DIGEST_SIZE); + store32(tb, authhandle2); + storebytes(tb, nonceodd, TPM_NONCE_SIZE); + store8(tb, cont); + storebytes(tb, authdata2, SHA1_DIGEST_SIZE); + + ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); + if (ret < 0) { + pr_info("trusted_key: authhmac failed (%d)\n", ret); + return ret; + } + + *datalen = LOAD32(tb->data, TPM_DATA_OFFSET); + ret = TSS_checkhmac2(tb->data, ordinal, nonceodd, + keyauth, SHA1_DIGEST_SIZE, + blobauth, SHA1_DIGEST_SIZE, + sizeof(uint32_t), TPM_DATA_OFFSET, + *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0, + 0); + if (ret < 0) { + pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret); + return ret; + } + memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen); + return 0; +} + +/* + * Have the TPM seal(encrypt) the symmetric key + */ +static int key_seal(struct trusted_key_payload *p, + struct trusted_key_options *o) +{ + struct tpm_buf *tb; + int ret; + + tb = kzalloc(sizeof *tb, GFP_KERNEL); + if (!tb) + return -ENOMEM; + + /* include migratable flag at end of sealed key */ + p->key[p->key_len] = p->migratable; + + ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth, + p->key, p->key_len + 1, p->blob, &p->blob_len, + o->blobauth, o->pcrinfo, o->pcrinfo_len); + if (ret < 0) + pr_info("trusted_key: srkseal failed (%d)\n", ret); + + kfree(tb); + return ret; +} + +/* + * Have the TPM unseal(decrypt) the symmetric key + */ +static int key_unseal(struct trusted_key_payload *p, + struct trusted_key_options *o) +{ + struct tpm_buf *tb; + int ret; + + tb = kzalloc(sizeof *tb, GFP_KERNEL); + if (!tb) + return -ENOMEM; + + ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len, + o->blobauth, p->key, &p->key_len); + if (ret < 0) + pr_info("trusted_key: srkunseal failed (%d)\n", ret); + else + /* pull migratable flag out of sealed key */ + p->migratable = p->key[--p->key_len]; + + kfree(tb); + return ret; +} + +enum { + Opt_err = -1, + Opt_new, Opt_load, Opt_update, + Opt_keyhandle, Opt_keyauth, Opt_blobauth, + Opt_pcrinfo, Opt_pcrlock, Opt_migratable +}; + +static const match_table_t key_tokens = { + {Opt_new, "new"}, + {Opt_load, "load"}, + {Opt_update, "update"}, + {Opt_keyhandle, "keyhandle=%s"}, + {Opt_keyauth, "keyauth=%s"}, + {Opt_blobauth, "blobauth=%s"}, + {Opt_pcrinfo, "pcrinfo=%s"}, + {Opt_pcrlock, "pcrlock=%s"}, + {Opt_migratable, "migratable=%s"}, + {Opt_err, NULL} +}; + +/* can have zero or more token= options */ +static int getoptions(char *c, struct trusted_key_payload *pay, + struct trusted_key_options *opt) +{ + substring_t args[MAX_OPT_ARGS]; + char *p = c; + int token; + int res; + unsigned long handle; + unsigned long lock; + + while ((p = strsep(&c, " \t"))) { + if (*p == '\0' || *p == ' ' || *p == '\t') + continue; + token = match_token(p, key_tokens, args); + + switch (token) { + case Opt_pcrinfo: + opt->pcrinfo_len = strlen(args[0].from) / 2; + if (opt->pcrinfo_len > MAX_PCRINFO_SIZE) + return -EINVAL; + res = hex2bin(opt->pcrinfo, args[0].from, + opt->pcrinfo_len); + if (res < 0) + return -EINVAL; + break; + case Opt_keyhandle: + res = kstrtoul(args[0].from, 16, &handle); + if (res < 0) + return -EINVAL; + opt->keytype = SEAL_keytype; + opt->keyhandle = handle; + break; + case Opt_keyauth: + if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) + return -EINVAL; + res = hex2bin(opt->keyauth, args[0].from, + SHA1_DIGEST_SIZE); + if (res < 0) + return -EINVAL; + break; + case Opt_blobauth: + if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) + return -EINVAL; + res = hex2bin(opt->blobauth, args[0].from, + SHA1_DIGEST_SIZE); + if (res < 0) + return -EINVAL; + break; + case Opt_migratable: + if (*args[0].from == '0') + pay->migratable = 0; + else + return -EINVAL; + break; + case Opt_pcrlock: + res = kstrtoul(args[0].from, 10, &lock); + if (res < 0) + return -EINVAL; + opt->pcrlock = lock; + break; + default: + return -EINVAL; + } + } + return 0; +} + +/* + * datablob_parse - parse the keyctl data and fill in the + * payload and options structures + * + * On success returns 0, otherwise -EINVAL. + */ +static int datablob_parse(char *datablob, struct trusted_key_payload *p, + struct trusted_key_options *o) +{ + substring_t args[MAX_OPT_ARGS]; + long keylen; + int ret = -EINVAL; + int key_cmd; + char *c; + + /* main command */ + c = strsep(&datablob, " \t"); + if (!c) + return -EINVAL; + key_cmd = match_token(c, key_tokens, args); + switch (key_cmd) { + case Opt_new: + /* first argument is key size */ + c = strsep(&datablob, " \t"); + if (!c) + return -EINVAL; + ret = kstrtol(c, 10, &keylen); + if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE) + return -EINVAL; + p->key_len = keylen; + ret = getoptions(datablob, p, o); + if (ret < 0) + return ret; + ret = Opt_new; + break; + case Opt_load: + /* first argument is sealed blob */ + c = strsep(&datablob, " \t"); + if (!c) + return -EINVAL; + p->blob_len = strlen(c) / 2; + if (p->blob_len > MAX_BLOB_SIZE) + return -EINVAL; + ret = hex2bin(p->blob, c, p->blob_len); + if (ret < 0) + return -EINVAL; + ret = getoptions(datablob, p, o); + if (ret < 0) + return ret; + ret = Opt_load; + break; + case Opt_update: + /* all arguments are options */ + ret = getoptions(datablob, p, o); + if (ret < 0) + return ret; + ret = Opt_update; + break; + case Opt_err: + return -EINVAL; + break; + } + return ret; +} + +static struct trusted_key_options *trusted_options_alloc(void) +{ + struct trusted_key_options *options; + + options = kzalloc(sizeof *options, GFP_KERNEL); + if (options) { + /* set any non-zero defaults */ + options->keytype = SRK_keytype; + options->keyhandle = SRKHANDLE; + } + return options; +} + +static struct trusted_key_payload *trusted_payload_alloc(struct key *key) +{ + struct trusted_key_payload *p = NULL; + int ret; + + ret = key_payload_reserve(key, sizeof *p); + if (ret < 0) + return p; + p = kzalloc(sizeof *p, GFP_KERNEL); + if (p) + p->migratable = 1; /* migratable by default */ + return p; +} + +/* + * trusted_instantiate - create a new trusted key + * + * Unseal an existing trusted blob or, for a new key, get a + * random key, then seal and create a trusted key-type key, + * adding it to the specified keyring. + * + * On success, return 0. Otherwise return errno. + */ +static int trusted_instantiate(struct key *key, + struct key_preparsed_payload *prep) +{ + struct trusted_key_payload *payload = NULL; + struct trusted_key_options *options = NULL; + size_t datalen = prep->datalen; + char *datablob; + int ret = 0; + int key_cmd; + size_t key_len; + + if (datalen <= 0 || datalen > 32767 || !prep->data) + return -EINVAL; + + datablob = kmalloc(datalen + 1, GFP_KERNEL); + if (!datablob) + return -ENOMEM; + memcpy(datablob, prep->data, datalen); + datablob[datalen] = '\0'; + + options = trusted_options_alloc(); + if (!options) { + ret = -ENOMEM; + goto out; + } + payload = trusted_payload_alloc(key); + if (!payload) { + ret = -ENOMEM; + goto out; + } + + key_cmd = datablob_parse(datablob, payload, options); + if (key_cmd < 0) { + ret = key_cmd; + goto out; + } + + dump_payload(payload); + dump_options(options); + + switch (key_cmd) { + case Opt_load: + ret = key_unseal(payload, options); + dump_payload(payload); + dump_options(options); + if (ret < 0) + pr_info("trusted_key: key_unseal failed (%d)\n", ret); + break; + case Opt_new: + key_len = payload->key_len; + ret = tpm_get_random(TPM_ANY_NUM, payload->key, key_len); + if (ret != key_len) { + pr_info("trusted_key: key_create failed (%d)\n", ret); + goto out; + } + ret = key_seal(payload, options); + if (ret < 0) + pr_info("trusted_key: key_seal failed (%d)\n", ret); + break; + default: + ret = -EINVAL; + goto out; + } + if (!ret && options->pcrlock) + ret = pcrlock(options->pcrlock); +out: + kfree(datablob); + kfree(options); + if (!ret) + rcu_assign_keypointer(key, payload); + else + kfree(payload); + return ret; +} + +static void trusted_rcu_free(struct rcu_head *rcu) +{ + struct trusted_key_payload *p; + + p = container_of(rcu, struct trusted_key_payload, rcu); + memset(p->key, 0, p->key_len); + kfree(p); +} + +/* + * trusted_update - reseal an existing key with new PCR values + */ +static int trusted_update(struct key *key, struct key_preparsed_payload *prep) +{ + struct trusted_key_payload *p = key->payload.data; + struct trusted_key_payload *new_p; + struct trusted_key_options *new_o; + size_t datalen = prep->datalen; + char *datablob; + int ret = 0; + + if (!p->migratable) + return -EPERM; + if (datalen <= 0 || datalen > 32767 || !prep->data) + return -EINVAL; + + datablob = kmalloc(datalen + 1, GFP_KERNEL); + if (!datablob) + return -ENOMEM; + new_o = trusted_options_alloc(); + if (!new_o) { + ret = -ENOMEM; + goto out; + } + new_p = trusted_payload_alloc(key); + if (!new_p) { + ret = -ENOMEM; + goto out; + } + + memcpy(datablob, prep->data, datalen); + datablob[datalen] = '\0'; + ret = datablob_parse(datablob, new_p, new_o); + if (ret != Opt_update) { + ret = -EINVAL; + kfree(new_p); + goto out; + } + /* copy old key values, and reseal with new pcrs */ + new_p->migratable = p->migratable; + new_p->key_len = p->key_len; + memcpy(new_p->key, p->key, p->key_len); + dump_payload(p); + dump_payload(new_p); + + ret = key_seal(new_p, new_o); + if (ret < 0) { + pr_info("trusted_key: key_seal failed (%d)\n", ret); + kfree(new_p); + goto out; + } + if (new_o->pcrlock) { + ret = pcrlock(new_o->pcrlock); + if (ret < 0) { + pr_info("trusted_key: pcrlock failed (%d)\n", ret); + kfree(new_p); + goto out; + } + } + rcu_assign_keypointer(key, new_p); + call_rcu(&p->rcu, trusted_rcu_free); +out: + kfree(datablob); + kfree(new_o); + return ret; +} + +/* + * trusted_read - copy the sealed blob data to userspace in hex. + * On success, return to userspace the trusted key datablob size. + */ +static long trusted_read(const struct key *key, char __user *buffer, + size_t buflen) +{ + struct trusted_key_payload *p; + char *ascii_buf; + char *bufp; + int i; + + p = rcu_dereference_key(key); + if (!p) + return -EINVAL; + if (!buffer || buflen <= 0) + return 2 * p->blob_len; + ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL); + if (!ascii_buf) + return -ENOMEM; + + bufp = ascii_buf; + for (i = 0; i < p->blob_len; i++) + bufp = hex_byte_pack(bufp, p->blob[i]); + if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) { + kfree(ascii_buf); + return -EFAULT; + } + kfree(ascii_buf); + return 2 * p->blob_len; +} + +/* + * trusted_destroy - before freeing the key, clear the decrypted data + */ +static void trusted_destroy(struct key *key) +{ + struct trusted_key_payload *p = key->payload.data; + + if (!p) + return; + memset(p->key, 0, p->key_len); + kfree(key->payload.data); +} + +struct key_type key_type_trusted = { + .name = "trusted", + .instantiate = trusted_instantiate, + .update = trusted_update, + .match = user_match, + .destroy = trusted_destroy, + .describe = user_describe, + .read = trusted_read, +}; + +EXPORT_SYMBOL_GPL(key_type_trusted); + +static void trusted_shash_release(void) +{ + if (hashalg) + crypto_free_shash(hashalg); + if (hmacalg) + crypto_free_shash(hmacalg); +} + +static int __init trusted_shash_alloc(void) +{ + int ret; + + hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(hmacalg)) { + pr_info("trusted_key: could not allocate crypto %s\n", + hmac_alg); + return PTR_ERR(hmacalg); + } + + hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(hashalg)) { + pr_info("trusted_key: could not allocate crypto %s\n", + hash_alg); + ret = PTR_ERR(hashalg); + goto hashalg_fail; + } + + return 0; + +hashalg_fail: + crypto_free_shash(hmacalg); + return ret; +} + +static int __init init_trusted(void) +{ + int ret; + + ret = trusted_shash_alloc(); + if (ret < 0) + return ret; + ret = register_key_type(&key_type_trusted); + if (ret < 0) + trusted_shash_release(); + return ret; +} + +static void __exit cleanup_trusted(void) +{ + trusted_shash_release(); + unregister_key_type(&key_type_trusted); +} + +late_initcall(init_trusted); +module_exit(cleanup_trusted); + +MODULE_LICENSE("GPL"); diff --git a/security/keys/trusted.h b/security/keys/trusted.h new file mode 100644 index 00000000000..3249fbd2b65 --- /dev/null +++ b/security/keys/trusted.h @@ -0,0 +1,134 @@ +#ifndef __TRUSTED_KEY_H +#define __TRUSTED_KEY_H + +/* implementation specific TPM constants */ +#define MAX_PCRINFO_SIZE 64 +#define MAX_BUF_SIZE 512 +#define TPM_GETRANDOM_SIZE 14 +#define TPM_OSAP_SIZE 36 +#define TPM_OIAP_SIZE 10 +#define TPM_SEAL_SIZE 87 +#define TPM_UNSEAL_SIZE 104 +#define TPM_SIZE_OFFSET 2 +#define TPM_RETURN_OFFSET 6 +#define TPM_DATA_OFFSET 10 + +#define LOAD32(buffer, offset) (ntohl(*(uint32_t *)&buffer[offset])) +#define LOAD32N(buffer, offset) (*(uint32_t *)&buffer[offset]) +#define LOAD16(buffer, offset) (ntohs(*(uint16_t *)&buffer[offset])) + +struct tpm_buf { + int len; + unsigned char data[MAX_BUF_SIZE]; +}; + +#define INIT_BUF(tb) (tb->len = 0) + +struct osapsess { + uint32_t handle; + unsigned char secret[SHA1_DIGEST_SIZE]; + unsigned char enonce[TPM_NONCE_SIZE]; +}; + +/* discrete values, but have to store in uint16_t for TPM use */ +enum { + SEAL_keytype = 1, + SRK_keytype = 4 +}; + +struct trusted_key_options { + uint16_t keytype; + uint32_t keyhandle; + unsigned char keyauth[SHA1_DIGEST_SIZE]; + unsigned char blobauth[SHA1_DIGEST_SIZE]; + uint32_t pcrinfo_len; + unsigned char pcrinfo[MAX_PCRINFO_SIZE]; + int pcrlock; +}; + +#define TPM_DEBUG 0 + +#if TPM_DEBUG +static inline void dump_options(struct trusted_key_options *o) +{ + pr_info("trusted_key: sealing key type %d\n", o->keytype); + pr_info("trusted_key: sealing key handle %0X\n", o->keyhandle); + pr_info("trusted_key: pcrlock %d\n", o->pcrlock); + pr_info("trusted_key: pcrinfo %d\n", o->pcrinfo_len); + print_hex_dump(KERN_INFO, "pcrinfo ", DUMP_PREFIX_NONE, + 16, 1, o->pcrinfo, o->pcrinfo_len, 0); +} + +static inline void dump_payload(struct trusted_key_payload *p) +{ + pr_info("trusted_key: key_len %d\n", p->key_len); + print_hex_dump(KERN_INFO, "key ", DUMP_PREFIX_NONE, + 16, 1, p->key, p->key_len, 0); + pr_info("trusted_key: bloblen %d\n", p->blob_len); + print_hex_dump(KERN_INFO, "blob ", DUMP_PREFIX_NONE, + 16, 1, p->blob, p->blob_len, 0); + pr_info("trusted_key: migratable %d\n", p->migratable); +} + +static inline void dump_sess(struct osapsess *s) +{ + print_hex_dump(KERN_INFO, "trusted-key: handle ", DUMP_PREFIX_NONE, + 16, 1, &s->handle, 4, 0); + pr_info("trusted-key: secret:\n"); + print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, + 16, 1, &s->secret, SHA1_DIGEST_SIZE, 0); + pr_info("trusted-key: enonce:\n"); + print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, + 16, 1, &s->enonce, SHA1_DIGEST_SIZE, 0); +} + +static inline void dump_tpm_buf(unsigned char *buf) +{ + int len; + + pr_info("\ntrusted-key: tpm buffer\n"); + len = LOAD32(buf, TPM_SIZE_OFFSET); + print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1, buf, len, 0); +} +#else +static inline void dump_options(struct trusted_key_options *o) +{ +} + +static inline void dump_payload(struct trusted_key_payload *p) +{ +} + +static inline void dump_sess(struct osapsess *s) +{ +} + +static inline void dump_tpm_buf(unsigned char *buf) +{ +} +#endif + +static inline void store8(struct tpm_buf *buf, const unsigned char value) +{ + buf->data[buf->len++] = value; +} + +static inline void store16(struct tpm_buf *buf, const uint16_t value) +{ + *(uint16_t *) & buf->data[buf->len] = htons(value); + buf->len += sizeof value; +} + +static inline void store32(struct tpm_buf *buf, const uint32_t value) +{ + *(uint32_t *) & buf->data[buf->len] = htonl(value); + buf->len += sizeof value; +} + +static inline void storebytes(struct tpm_buf *buf, const unsigned char *in, + const int len) +{ + memcpy(buf->data + buf->len, in, len); + buf->len += len; +} +#endif diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c index 7c687d56822..faa2caeb593 100644 --- a/security/keys/user_defined.c +++ b/security/keys/user_defined.c @@ -18,34 +18,56 @@ #include <asm/uaccess.h> #include "internal.h" +static int logon_vet_description(const char *desc); + /* * user defined keys take an arbitrary string as the description and an * arbitrary blob of data as the payload */ struct key_type key_type_user = { - .name = "user", - .instantiate = user_instantiate, - .update = user_update, - .match = user_match, - .revoke = user_revoke, - .destroy = user_destroy, - .describe = user_describe, - .read = user_read, + .name = "user", + .def_lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, + .instantiate = user_instantiate, + .update = user_update, + .match = user_match, + .revoke = user_revoke, + .destroy = user_destroy, + .describe = user_describe, + .read = user_read, }; EXPORT_SYMBOL_GPL(key_type_user); -/*****************************************************************************/ +/* + * This key type is essentially the same as key_type_user, but it does + * not define a .read op. This is suitable for storing username and + * password pairs in the keyring that you do not want to be readable + * from userspace. + */ +struct key_type key_type_logon = { + .name = "logon", + .def_lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, + .instantiate = user_instantiate, + .update = user_update, + .match = user_match, + .revoke = user_revoke, + .destroy = user_destroy, + .describe = user_describe, + .vet_description = logon_vet_description, +}; +EXPORT_SYMBOL_GPL(key_type_logon); + /* * instantiate a user defined key */ -int user_instantiate(struct key *key, const void *data, size_t datalen) +int user_instantiate(struct key *key, struct key_preparsed_payload *prep) { struct user_key_payload *upayload; + size_t datalen = prep->datalen; int ret; ret = -EINVAL; - if (datalen <= 0 || datalen > 32767 || !data) + if (datalen <= 0 || datalen > 32767 || !prep->data) goto error; ret = key_payload_reserve(key, datalen); @@ -59,43 +81,28 @@ int user_instantiate(struct key *key, const void *data, size_t datalen) /* attach the data */ upayload->datalen = datalen; - memcpy(upayload->data, data, datalen); - rcu_assign_pointer(key->payload.data, upayload); + memcpy(upayload->data, prep->data, datalen); + rcu_assign_keypointer(key, upayload); ret = 0; error: return ret; - -} /* end user_instantiate() */ +} EXPORT_SYMBOL_GPL(user_instantiate); -/*****************************************************************************/ -/* - * dispose of the old data from an updated user defined key - */ -static void user_update_rcu_disposal(struct rcu_head *rcu) -{ - struct user_key_payload *upayload; - - upayload = container_of(rcu, struct user_key_payload, rcu); - - kfree(upayload); - -} /* end user_update_rcu_disposal() */ - -/*****************************************************************************/ /* * update a user defined key * - the key's semaphore is write-locked */ -int user_update(struct key *key, const void *data, size_t datalen) +int user_update(struct key *key, struct key_preparsed_payload *prep) { struct user_key_payload *upayload, *zap; + size_t datalen = prep->datalen; int ret; ret = -EINVAL; - if (datalen <= 0 || datalen > 32767 || !data) + if (datalen <= 0 || datalen > 32767 || !prep->data) goto error; /* construct a replacement payload */ @@ -105,7 +112,7 @@ int user_update(struct key *key, const void *data, size_t datalen) goto error; upayload->datalen = datalen; - memcpy(upayload->data, data, datalen); + memcpy(upayload->data, prep->data, datalen); /* check the quota and attach the new data */ zap = upayload; @@ -115,32 +122,29 @@ int user_update(struct key *key, const void *data, size_t datalen) if (ret == 0) { /* attach the new data, displacing the old */ zap = key->payload.data; - rcu_assign_pointer(key->payload.data, upayload); + rcu_assign_keypointer(key, upayload); key->expiry = 0; } - call_rcu(&zap->rcu, user_update_rcu_disposal); + if (zap) + kfree_rcu(zap, rcu); error: return ret; - -} /* end user_update() */ +} EXPORT_SYMBOL_GPL(user_update); -/*****************************************************************************/ /* * match users on their name */ int user_match(const struct key *key, const void *description) { return strcmp(key->description, description) == 0; - -} /* end user_match() */ +} EXPORT_SYMBOL_GPL(user_match); -/*****************************************************************************/ /* * dispose of the links from a revoked keyring * - called with the key sem write-locked @@ -153,15 +157,13 @@ void user_revoke(struct key *key) key_payload_reserve(key, 0); if (upayload) { - rcu_assign_pointer(key->payload.data, NULL); - call_rcu(&upayload->rcu, user_update_rcu_disposal); + rcu_assign_keypointer(key, NULL); + kfree_rcu(upayload, rcu); } - -} /* end user_revoke() */ +} EXPORT_SYMBOL(user_revoke); -/*****************************************************************************/ /* * dispose of the data dangling from the corpse of a user key */ @@ -170,26 +172,22 @@ void user_destroy(struct key *key) struct user_key_payload *upayload = key->payload.data; kfree(upayload); - -} /* end user_destroy() */ +} EXPORT_SYMBOL_GPL(user_destroy); -/*****************************************************************************/ /* * describe the user key */ void user_describe(const struct key *key, struct seq_file *m) { seq_puts(m, key->description); - - seq_printf(m, ": %u", key->datalen); - -} /* end user_describe() */ + if (key_is_instantiated(key)) + seq_printf(m, ": %u", key->datalen); +} EXPORT_SYMBOL_GPL(user_describe); -/*****************************************************************************/ /* * read the key data * - the key's semaphore is read-locked @@ -199,7 +197,7 @@ long user_read(const struct key *key, char __user *buffer, size_t buflen) struct user_key_payload *upayload; long ret; - upayload = rcu_dereference(key->payload.data); + upayload = rcu_dereference_key(key); ret = upayload->datalen; /* we can return the data as is */ @@ -212,7 +210,23 @@ long user_read(const struct key *key, char __user *buffer, size_t buflen) } return ret; - -} /* end user_read() */ +} EXPORT_SYMBOL_GPL(user_read); + +/* Vet the description for a "logon" key */ +static int logon_vet_description(const char *desc) +{ + char *p; + + /* require a "qualified" description string */ + p = strchr(desc, ':'); + if (!p) + return -EINVAL; + + /* also reject description with ':' as first char */ + if (p == desc) + return -EINVAL; + + return 0; +} |