diff options
Diffstat (limited to 'security')
| -rw-r--r-- | security/apparmor/Kconfig | 12 | ||||
| -rw-r--r-- | security/apparmor/Makefile | 1 | ||||
| -rw-r--r-- | security/apparmor/apparmorfs.c | 37 | ||||
| -rw-r--r-- | security/apparmor/crypto.c | 97 | ||||
| -rw-r--r-- | security/apparmor/include/apparmorfs.h | 1 | ||||
| -rw-r--r-- | security/apparmor/include/crypto.h | 36 | ||||
| -rw-r--r-- | security/apparmor/include/policy.h | 1 | ||||
| -rw-r--r-- | security/apparmor/policy_unpack.c | 20 |
8 files changed, 199 insertions, 6 deletions
diff --git a/security/apparmor/Kconfig b/security/apparmor/Kconfig index 9b9013b2e32..d49c53960b6 100644 --- a/security/apparmor/Kconfig +++ b/security/apparmor/Kconfig @@ -29,3 +29,15 @@ config SECURITY_APPARMOR_BOOTPARAM_VALUE boot. If you are unsure how to answer this question, answer 1. + +config SECURITY_APPARMOR_HASH + bool "SHA1 hash of loaded profiles" + depends on SECURITY_APPARMOR + depends on CRYPTO + select CRYPTO_SHA1 + default y + + help + This option selects whether sha1 hashing is done against loaded + profiles and exported for inspection to user space via the apparmor + filesystem. diff --git a/security/apparmor/Makefile b/security/apparmor/Makefile index 0831e049072..d693df87481 100644 --- a/security/apparmor/Makefile +++ b/security/apparmor/Makefile @@ -5,6 +5,7 @@ obj-$(CONFIG_SECURITY_APPARMOR) += apparmor.o apparmor-y := apparmorfs.o audit.o capability.o context.o ipc.o lib.o match.o \ path.o domain.o policy.o policy_unpack.o procattr.o lsm.o \ resource.o sid.o file.o +apparmor-$(CONFIG_SECURITY_APPARMOR_HASH) += crypto.o clean-files := capability_names.h rlim_names.h diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c index d708a55d072..95c2b2689a0 100644 --- a/security/apparmor/apparmorfs.c +++ b/security/apparmor/apparmorfs.c @@ -26,6 +26,7 @@ #include "include/apparmorfs.h" #include "include/audit.h" #include "include/context.h" +#include "include/crypto.h" #include "include/policy.h" #include "include/resource.h" @@ -319,6 +320,34 @@ static const struct file_operations aa_fs_profattach_fops = { .release = aa_fs_seq_profile_release, }; +static int aa_fs_seq_hash_show(struct seq_file *seq, void *v) +{ + struct aa_replacedby *r = seq->private; + struct aa_profile *profile = aa_get_profile_rcu(&r->profile); + unsigned int i, size = aa_hash_size(); + + if (profile->hash) { + for (i = 0; i < size; i++) + seq_printf(seq, "%.2x", profile->hash[i]); + seq_puts(seq, "\n"); + } + + return 0; +} + +static int aa_fs_seq_hash_open(struct inode *inode, struct file *file) +{ + return single_open(file, aa_fs_seq_hash_show, inode->i_private); +} + +static const struct file_operations aa_fs_seq_hash_fops = { + .owner = THIS_MODULE, + .open = aa_fs_seq_hash_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + /** fns to setup dynamic per profile/namespace files **/ void __aa_fs_profile_rmdir(struct aa_profile *profile) { @@ -420,6 +449,14 @@ int __aa_fs_profile_mkdir(struct aa_profile *profile, struct dentry *parent) goto fail; profile->dents[AAFS_PROF_ATTACH] = dent; + if (profile->hash) { + dent = create_profile_file(dir, "sha1", profile, + &aa_fs_seq_hash_fops); + if (IS_ERR(dent)) + goto fail; + profile->dents[AAFS_PROF_HASH] = dent; + } + list_for_each_entry(child, &profile->base.profiles, base.list) { error = __aa_fs_profile_mkdir(child, prof_child_dir(profile)); if (error) diff --git a/security/apparmor/crypto.c b/security/apparmor/crypto.c new file mode 100644 index 00000000000..d6222ba4e91 --- /dev/null +++ b/security/apparmor/crypto.c @@ -0,0 +1,97 @@ +/* + * AppArmor security module + * + * This file contains AppArmor policy loading interface function definitions. + * + * Copyright 2013 Canonical Ltd. + * + * 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. + * + * Fns to provide a checksum of policy that has been loaded this can be + * compared to userspace policy compiles to check loaded policy is what + * it should be. + */ + +#include <linux/crypto.h> + +#include "include/apparmor.h" +#include "include/crypto.h" + +static unsigned int apparmor_hash_size; + +static struct crypto_hash *apparmor_tfm; + +unsigned int aa_hash_size(void) +{ + return apparmor_hash_size; +} + +int aa_calc_profile_hash(struct aa_profile *profile, u32 version, void *start, + size_t len) +{ + struct scatterlist sg[2]; + struct hash_desc desc = { + .tfm = apparmor_tfm, + .flags = 0 + }; + int error = -ENOMEM; + u32 le32_version = cpu_to_le32(version); + + if (!apparmor_tfm) + return 0; + + sg_init_table(sg, 2); + sg_set_buf(&sg[0], &le32_version, 4); + sg_set_buf(&sg[1], (u8 *) start, len); + + profile->hash = kzalloc(apparmor_hash_size, GFP_KERNEL); + if (!profile->hash) + goto fail; + + error = crypto_hash_init(&desc); + if (error) + goto fail; + error = crypto_hash_update(&desc, &sg[0], 4); + if (error) + goto fail; + error = crypto_hash_update(&desc, &sg[1], len); + if (error) + goto fail; + error = crypto_hash_final(&desc, profile->hash); + if (error) + goto fail; + + return 0; + +fail: + kfree(profile->hash); + profile->hash = NULL; + + return error; +} + +static int __init init_profile_hash(void) +{ + struct crypto_hash *tfm; + + if (!apparmor_initialized) + return 0; + + tfm = crypto_alloc_hash("sha1", 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(tfm)) { + int error = PTR_ERR(tfm); + AA_ERROR("failed to setup profile sha1 hashing: %d\n", error); + return error; + } + apparmor_tfm = tfm; + apparmor_hash_size = crypto_hash_digestsize(apparmor_tfm); + + aa_info_message("AppArmor sha1 policy hashing enabled"); + + return 0; +} + +late_initcall(init_profile_hash); diff --git a/security/apparmor/include/apparmorfs.h b/security/apparmor/include/apparmorfs.h index f91712cf1b3..414e56878dd 100644 --- a/security/apparmor/include/apparmorfs.h +++ b/security/apparmor/include/apparmorfs.h @@ -82,6 +82,7 @@ enum aafs_prof_type { AAFS_PROF_NAME, AAFS_PROF_MODE, AAFS_PROF_ATTACH, + AAFS_PROF_HASH, AAFS_PROF_SIZEOF, }; diff --git a/security/apparmor/include/crypto.h b/security/apparmor/include/crypto.h new file mode 100644 index 00000000000..dc418e5024d --- /dev/null +++ b/security/apparmor/include/crypto.h @@ -0,0 +1,36 @@ +/* + * AppArmor security module + * + * This file contains AppArmor policy loading interface function definitions. + * + * Copyright 2013 Canonical Ltd. + * + * 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 __APPARMOR_CRYPTO_H +#define __APPARMOR_CRYPTO_H + +#include "policy.h" + +#ifdef CONFIG_SECURITY_APPARMOR_HASH +unsigned int aa_hash_size(void); +int aa_calc_profile_hash(struct aa_profile *profile, u32 version, void *start, + size_t len); +#else +static inline int aa_calc_profile_hash(struct aa_profile *profile, u32 version, + void *start, size_t len) +{ + return 0; +} + +static inline unsigned int aa_hash_size(void) +{ + return 0; +} +#endif + +#endif /* __APPARMOR_CRYPTO_H */ diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h index 59b36372ae4..f2d4b6348cb 100644 --- a/security/apparmor/include/policy.h +++ b/security/apparmor/include/policy.h @@ -219,6 +219,7 @@ struct aa_profile { struct aa_caps caps; struct aa_rlimit rlimits; + unsigned char *hash; char *dirname; struct dentry *dents[AAFS_PROF_SIZEOF]; }; diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c index bdaef2e1b2a..a689f10930b 100644 --- a/security/apparmor/policy_unpack.c +++ b/security/apparmor/policy_unpack.c @@ -24,6 +24,7 @@ #include "include/apparmor.h" #include "include/audit.h" #include "include/context.h" +#include "include/crypto.h" #include "include/match.h" #include "include/policy.h" #include "include/policy_unpack.h" @@ -758,10 +759,12 @@ int aa_unpack(void *udata, size_t size, struct list_head *lh, const char **ns) *ns = NULL; while (e.pos < e.end) { + void *start; error = verify_header(&e, e.pos == e.start, ns); if (error) goto fail; + start = e.pos; profile = unpack_profile(&e); if (IS_ERR(profile)) { error = PTR_ERR(profile); @@ -769,16 +772,18 @@ int aa_unpack(void *udata, size_t size, struct list_head *lh, const char **ns) } error = verify_profile(profile); - if (error) { - aa_free_profile(profile); - goto fail; - } + if (error) + goto fail_profile; + + error = aa_calc_profile_hash(profile, e.version, start, + e.pos - start); + if (error) + goto fail_profile; ent = aa_load_ent_alloc(); if (!ent) { error = -ENOMEM; - aa_put_profile(profile); - goto fail; + goto fail_profile; } ent->new = profile; @@ -787,6 +792,9 @@ int aa_unpack(void *udata, size_t size, struct list_head *lh, const char **ns) return 0; +fail_profile: + aa_put_profile(profile); + fail: list_for_each_entry_safe(ent, tmp, lh, list) { list_del_init(&ent->list); |