diff options
Diffstat (limited to 'fs/ecryptfs/crypto.c')
| -rw-r--r-- | fs/ecryptfs/crypto.c | 1344 |
1 files changed, 798 insertions, 546 deletions
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index a066e109ad9..2f6735dbf1a 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -33,18 +33,12 @@ #include <linux/crypto.h> #include <linux/file.h> #include <linux/scatterlist.h> +#include <linux/slab.h> +#include <asm/unaligned.h> #include "ecryptfs_kernel.h" -static int -ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, - struct page *dst_page, int dst_offset, - struct page *src_page, int src_offset, int size, - unsigned char *iv); -static int -ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, - struct page *dst_page, int dst_offset, - struct page *src_page, int src_offset, int size, - unsigned char *iv); +#define DECRYPT 0 +#define ENCRYPT 1 /** * ecryptfs_to_hex @@ -119,21 +113,21 @@ static int ecryptfs_calculate_md5(char *dst, if (rc) { printk(KERN_ERR "%s: Error initializing crypto hash; rc = [%d]\n", - __FUNCTION__, rc); + __func__, rc); goto out; } rc = crypto_hash_update(&desc, &sg, len); if (rc) { printk(KERN_ERR "%s: Error updating crypto hash; rc = [%d]\n", - __FUNCTION__, rc); + __func__, rc); goto out; } rc = crypto_hash_final(&desc, dst); if (rc) { printk(KERN_ERR "%s: Error finalizing crypto hash; rc = [%d]\n", - __FUNCTION__, rc); + __func__, rc); goto out; } out: @@ -174,8 +168,8 @@ out: * * Returns zero on success; non-zero on error. */ -static int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat, - loff_t offset) +int ecryptfs_derive_iv(char *iv, struct ecryptfs_crypt_stat *crypt_stat, + loff_t offset) { int rc = 0; char dst[MD5_DIGEST_SIZE]; @@ -241,16 +235,14 @@ void ecryptfs_destroy_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat) struct ecryptfs_key_sig *key_sig, *key_sig_tmp; if (crypt_stat->tfm) - crypto_free_blkcipher(crypt_stat->tfm); + crypto_free_ablkcipher(crypt_stat->tfm); if (crypt_stat->hash_tfm) crypto_free_hash(crypt_stat->hash_tfm); - mutex_lock(&crypt_stat->keysig_list_mutex); list_for_each_entry_safe(key_sig, key_sig_tmp, &crypt_stat->keysig_list, crypt_stat_list) { list_del(&key_sig->crypt_stat_list); kmem_cache_free(ecryptfs_key_sig_cache, key_sig); } - mutex_unlock(&crypt_stat->keysig_list_mutex); memset(crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat)); } @@ -266,7 +258,6 @@ void ecryptfs_destroy_mount_crypt_stat( &mount_crypt_stat->global_auth_tok_list, mount_crypt_stat_list) { list_del(&auth_tok->mount_crypt_stat_list); - mount_crypt_stat->num_global_auth_toks--; if (auth_tok->global_auth_tok_key && !(auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID)) key_put(auth_tok->global_auth_tok_key); @@ -302,17 +293,14 @@ int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg, while (size > 0 && i < sg_size) { pg = virt_to_page(addr); offset = offset_in_page(addr); - if (sg) - sg_set_page(&sg[i], pg, 0, offset); + sg_set_page(&sg[i], pg, 0, offset); remainder_of_page = PAGE_CACHE_SIZE - offset; if (size >= remainder_of_page) { - if (sg) - sg[i].length = remainder_of_page; + sg[i].length = remainder_of_page; addr += remainder_of_page; size -= remainder_of_page; } else { - if (sg) - sg[i].length = size; + sg[i].length = size; addr += size; size = 0; } @@ -323,133 +311,158 @@ int virt_to_scatterlist(const void *addr, int size, struct scatterlist *sg, return i; } +struct extent_crypt_result { + struct completion completion; + int rc; +}; + +static void extent_crypt_complete(struct crypto_async_request *req, int rc) +{ + struct extent_crypt_result *ecr = req->data; + + if (rc == -EINPROGRESS) + return; + + ecr->rc = rc; + complete(&ecr->completion); +} + /** - * encrypt_scatterlist + * crypt_scatterlist * @crypt_stat: Pointer to the crypt_stat struct to initialize. - * @dest_sg: Destination of encrypted data - * @src_sg: Data to be encrypted - * @size: Length of data to be encrypted - * @iv: iv to use during encryption + * @dst_sg: Destination of the data after performing the crypto operation + * @src_sg: Data to be encrypted or decrypted + * @size: Length of data + * @iv: IV to use + * @op: ENCRYPT or DECRYPT to indicate the desired operation * - * Returns the number of bytes encrypted; negative value on error + * Returns the number of bytes encrypted or decrypted; negative value on error */ -static int encrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat, - struct scatterlist *dest_sg, - struct scatterlist *src_sg, int size, - unsigned char *iv) +static int crypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat, + struct scatterlist *dst_sg, + struct scatterlist *src_sg, int size, + unsigned char *iv, int op) { - struct blkcipher_desc desc = { - .tfm = crypt_stat->tfm, - .info = iv, - .flags = CRYPTO_TFM_REQ_MAY_SLEEP - }; + struct ablkcipher_request *req = NULL; + struct extent_crypt_result ecr; int rc = 0; BUG_ON(!crypt_stat || !crypt_stat->tfm || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)); if (unlikely(ecryptfs_verbosity > 0)) { - ecryptfs_printk(KERN_DEBUG, "Key size [%d]; key:\n", + ecryptfs_printk(KERN_DEBUG, "Key size [%zd]; key:\n", crypt_stat->key_size); ecryptfs_dump_hex(crypt_stat->key, crypt_stat->key_size); } - /* Consider doing this once, when the file is opened */ + + init_completion(&ecr.completion); + mutex_lock(&crypt_stat->cs_tfm_mutex); - if (!(crypt_stat->flags & ECRYPTFS_KEY_SET)) { - rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key, - crypt_stat->key_size); - crypt_stat->flags |= ECRYPTFS_KEY_SET; - } - if (rc) { - ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n", - rc); + req = ablkcipher_request_alloc(crypt_stat->tfm, GFP_NOFS); + if (!req) { mutex_unlock(&crypt_stat->cs_tfm_mutex); - rc = -EINVAL; + rc = -ENOMEM; goto out; } - ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes.\n", size); - crypto_blkcipher_encrypt_iv(&desc, dest_sg, src_sg, size); + + ablkcipher_request_set_callback(req, + CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, + extent_crypt_complete, &ecr); + /* Consider doing this once, when the file is opened */ + if (!(crypt_stat->flags & ECRYPTFS_KEY_SET)) { + rc = crypto_ablkcipher_setkey(crypt_stat->tfm, crypt_stat->key, + crypt_stat->key_size); + if (rc) { + ecryptfs_printk(KERN_ERR, + "Error setting key; rc = [%d]\n", + rc); + mutex_unlock(&crypt_stat->cs_tfm_mutex); + rc = -EINVAL; + goto out; + } + crypt_stat->flags |= ECRYPTFS_KEY_SET; + } mutex_unlock(&crypt_stat->cs_tfm_mutex); + ablkcipher_request_set_crypt(req, src_sg, dst_sg, size, iv); + rc = op == ENCRYPT ? crypto_ablkcipher_encrypt(req) : + crypto_ablkcipher_decrypt(req); + if (rc == -EINPROGRESS || rc == -EBUSY) { + struct extent_crypt_result *ecr = req->base.data; + + wait_for_completion(&ecr->completion); + rc = ecr->rc; + reinit_completion(&ecr->completion); + } out: + ablkcipher_request_free(req); return rc; } /** - * ecryptfs_lower_offset_for_extent + * lower_offset_for_page * * Convert an eCryptfs page index into a lower byte offset */ -static void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num, - struct ecryptfs_crypt_stat *crypt_stat) +static loff_t lower_offset_for_page(struct ecryptfs_crypt_stat *crypt_stat, + struct page *page) { - (*offset) = (crypt_stat->num_header_bytes_at_front - + (crypt_stat->extent_size * extent_num)); + return ecryptfs_lower_header_size(crypt_stat) + + ((loff_t)page->index << PAGE_CACHE_SHIFT); } /** - * ecryptfs_encrypt_extent - * @enc_extent_page: Allocated page into which to encrypt the data in - * @page + * crypt_extent * @crypt_stat: crypt_stat containing cryptographic context for the * encryption operation - * @page: Page containing plaintext data extent to encrypt + * @dst_page: The page to write the result into + * @src_page: The page to read from * @extent_offset: Page extent offset for use in generating IV + * @op: ENCRYPT or DECRYPT to indicate the desired operation * - * Encrypts one extent of data. + * Encrypts or decrypts one extent of data. * * Return zero on success; non-zero otherwise */ -static int ecryptfs_encrypt_extent(struct page *enc_extent_page, - struct ecryptfs_crypt_stat *crypt_stat, - struct page *page, - unsigned long extent_offset) +static int crypt_extent(struct ecryptfs_crypt_stat *crypt_stat, + struct page *dst_page, + struct page *src_page, + unsigned long extent_offset, int op) { + pgoff_t page_index = op == ENCRYPT ? src_page->index : dst_page->index; loff_t extent_base; char extent_iv[ECRYPTFS_MAX_IV_BYTES]; + struct scatterlist src_sg, dst_sg; + size_t extent_size = crypt_stat->extent_size; int rc; - extent_base = (((loff_t)page->index) - * (PAGE_CACHE_SIZE / crypt_stat->extent_size)); + extent_base = (((loff_t)page_index) * (PAGE_CACHE_SIZE / extent_size)); rc = ecryptfs_derive_iv(extent_iv, crypt_stat, (extent_base + extent_offset)); if (rc) { - ecryptfs_printk(KERN_ERR, "Error attempting to " - "derive IV for extent [0x%.16x]; " - "rc = [%d]\n", (extent_base + extent_offset), - rc); + ecryptfs_printk(KERN_ERR, "Error attempting to derive IV for " + "extent [0x%.16llx]; rc = [%d]\n", + (unsigned long long)(extent_base + extent_offset), rc); goto out; } - if (unlikely(ecryptfs_verbosity > 0)) { - ecryptfs_printk(KERN_DEBUG, "Encrypting extent " - "with iv:\n"); - ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes); - ecryptfs_printk(KERN_DEBUG, "First 8 bytes before " - "encryption:\n"); - ecryptfs_dump_hex((char *) - (page_address(page) - + (extent_offset * crypt_stat->extent_size)), - 8); - } - rc = ecryptfs_encrypt_page_offset(crypt_stat, enc_extent_page, 0, - page, (extent_offset - * crypt_stat->extent_size), - crypt_stat->extent_size, extent_iv); + + sg_init_table(&src_sg, 1); + sg_init_table(&dst_sg, 1); + + sg_set_page(&src_sg, src_page, extent_size, + extent_offset * extent_size); + sg_set_page(&dst_sg, dst_page, extent_size, + extent_offset * extent_size); + + rc = crypt_scatterlist(crypt_stat, &dst_sg, &src_sg, extent_size, + extent_iv, op); if (rc < 0) { - printk(KERN_ERR "%s: Error attempting to encrypt page with " - "page->index = [%ld], extent_offset = [%ld]; " - "rc = [%d]\n", __FUNCTION__, page->index, extent_offset, - rc); + printk(KERN_ERR "%s: Error attempting to crypt page with " + "page_index = [%ld], extent_offset = [%ld]; " + "rc = [%d]\n", __func__, page_index, extent_offset, rc); goto out; } rc = 0; - if (unlikely(ecryptfs_verbosity > 0)) { - ecryptfs_printk(KERN_DEBUG, "Encrypt extent [0x%.16x]; " - "rc = [%d]\n", (extent_base + extent_offset), - rc); - ecryptfs_printk(KERN_DEBUG, "First 8 bytes after " - "encryption:\n"); - ecryptfs_dump_hex((char *)(page_address(enc_extent_page)), 8); - } out: return rc; } @@ -474,117 +487,52 @@ int ecryptfs_encrypt_page(struct page *page) { struct inode *ecryptfs_inode; struct ecryptfs_crypt_stat *crypt_stat; - char *enc_extent_virt = NULL; - struct page *enc_extent_page; + char *enc_extent_virt; + struct page *enc_extent_page = NULL; loff_t extent_offset; + loff_t lower_offset; int rc = 0; ecryptfs_inode = page->mapping->host; crypt_stat = &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); - if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { - rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, page, - 0, PAGE_CACHE_SIZE); - if (rc) - printk(KERN_ERR "%s: Error attempting to copy " - "page at index [%ld]\n", __FUNCTION__, - page->index); - goto out; - } - enc_extent_virt = kmalloc(PAGE_CACHE_SIZE, GFP_USER); - if (!enc_extent_virt) { + BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)); + enc_extent_page = alloc_page(GFP_USER); + if (!enc_extent_page) { rc = -ENOMEM; ecryptfs_printk(KERN_ERR, "Error allocating memory for " "encrypted extent\n"); goto out; } - enc_extent_page = virt_to_page(enc_extent_virt); + for (extent_offset = 0; extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); extent_offset++) { - loff_t offset; - - rc = ecryptfs_encrypt_extent(enc_extent_page, crypt_stat, page, - extent_offset); + rc = crypt_extent(crypt_stat, enc_extent_page, page, + extent_offset, ENCRYPT); if (rc) { printk(KERN_ERR "%s: Error encrypting extent; " - "rc = [%d]\n", __FUNCTION__, rc); - goto out; - } - ecryptfs_lower_offset_for_extent( - &offset, ((((loff_t)page->index) - * (PAGE_CACHE_SIZE - / crypt_stat->extent_size)) - + extent_offset), crypt_stat); - rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt, - offset, crypt_stat->extent_size); - if (rc) { - ecryptfs_printk(KERN_ERR, "Error attempting " - "to write lower page; rc = [%d]" - "\n", rc); + "rc = [%d]\n", __func__, rc); goto out; } } -out: - kfree(enc_extent_virt); - return rc; -} - -static int ecryptfs_decrypt_extent(struct page *page, - struct ecryptfs_crypt_stat *crypt_stat, - struct page *enc_extent_page, - unsigned long extent_offset) -{ - loff_t extent_base; - char extent_iv[ECRYPTFS_MAX_IV_BYTES]; - int rc; - extent_base = (((loff_t)page->index) - * (PAGE_CACHE_SIZE / crypt_stat->extent_size)); - rc = ecryptfs_derive_iv(extent_iv, crypt_stat, - (extent_base + extent_offset)); - if (rc) { - ecryptfs_printk(KERN_ERR, "Error attempting to " - "derive IV for extent [0x%.16x]; " - "rc = [%d]\n", (extent_base + extent_offset), - rc); - goto out; - } - if (unlikely(ecryptfs_verbosity > 0)) { - ecryptfs_printk(KERN_DEBUG, "Decrypting extent " - "with iv:\n"); - ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes); - ecryptfs_printk(KERN_DEBUG, "First 8 bytes before " - "decryption:\n"); - ecryptfs_dump_hex((char *) - (page_address(enc_extent_page) - + (extent_offset * crypt_stat->extent_size)), - 8); - } - rc = ecryptfs_decrypt_page_offset(crypt_stat, page, - (extent_offset - * crypt_stat->extent_size), - enc_extent_page, 0, - crypt_stat->extent_size, extent_iv); + lower_offset = lower_offset_for_page(crypt_stat, page); + enc_extent_virt = kmap(enc_extent_page); + rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt, lower_offset, + PAGE_CACHE_SIZE); + kunmap(enc_extent_page); if (rc < 0) { - printk(KERN_ERR "%s: Error attempting to decrypt to page with " - "page->index = [%ld], extent_offset = [%ld]; " - "rc = [%d]\n", __FUNCTION__, page->index, extent_offset, - rc); + ecryptfs_printk(KERN_ERR, + "Error attempting to write lower page; rc = [%d]\n", + rc); goto out; } rc = 0; - if (unlikely(ecryptfs_verbosity > 0)) { - ecryptfs_printk(KERN_DEBUG, "Decrypt extent [0x%.16x]; " - "rc = [%d]\n", (extent_base + extent_offset), - rc); - ecryptfs_printk(KERN_DEBUG, "First 8 bytes after " - "decryption:\n"); - ecryptfs_dump_hex((char *)(page_address(page) - + (extent_offset - * crypt_stat->extent_size)), 8); - } out: + if (enc_extent_page) { + __free_page(enc_extent_page); + } return rc; } @@ -608,171 +556,48 @@ int ecryptfs_decrypt_page(struct page *page) { struct inode *ecryptfs_inode; struct ecryptfs_crypt_stat *crypt_stat; - char *enc_extent_virt = NULL; - struct page *enc_extent_page; + char *page_virt; unsigned long extent_offset; + loff_t lower_offset; int rc = 0; ecryptfs_inode = page->mapping->host; crypt_stat = &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); - if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { - rc = ecryptfs_read_lower_page_segment(page, page->index, 0, - PAGE_CACHE_SIZE, - ecryptfs_inode); - if (rc) - printk(KERN_ERR "%s: Error attempting to copy " - "page at index [%ld]\n", __FUNCTION__, - page->index); - goto out; - } - enc_extent_virt = kmalloc(PAGE_CACHE_SIZE, GFP_USER); - if (!enc_extent_virt) { - rc = -ENOMEM; - ecryptfs_printk(KERN_ERR, "Error allocating memory for " - "encrypted extent\n"); + BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)); + + lower_offset = lower_offset_for_page(crypt_stat, page); + page_virt = kmap(page); + rc = ecryptfs_read_lower(page_virt, lower_offset, PAGE_CACHE_SIZE, + ecryptfs_inode); + kunmap(page); + if (rc < 0) { + ecryptfs_printk(KERN_ERR, + "Error attempting to read lower page; rc = [%d]\n", + rc); goto out; } - enc_extent_page = virt_to_page(enc_extent_virt); + for (extent_offset = 0; extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); extent_offset++) { - loff_t offset; - - ecryptfs_lower_offset_for_extent( - &offset, ((page->index * (PAGE_CACHE_SIZE - / crypt_stat->extent_size)) - + extent_offset), crypt_stat); - rc = ecryptfs_read_lower(enc_extent_virt, offset, - crypt_stat->extent_size, - ecryptfs_inode); - if (rc) { - ecryptfs_printk(KERN_ERR, "Error attempting " - "to read lower page; rc = [%d]" - "\n", rc); - goto out; - } - rc = ecryptfs_decrypt_extent(page, crypt_stat, enc_extent_page, - extent_offset); + rc = crypt_extent(crypt_stat, page, page, + extent_offset, DECRYPT); if (rc) { printk(KERN_ERR "%s: Error encrypting extent; " - "rc = [%d]\n", __FUNCTION__, rc); + "rc = [%d]\n", __func__, rc); goto out; } } out: - kfree(enc_extent_virt); - return rc; -} - -/** - * decrypt_scatterlist - * @crypt_stat: Cryptographic context - * @dest_sg: The destination scatterlist to decrypt into - * @src_sg: The source scatterlist to decrypt from - * @size: The number of bytes to decrypt - * @iv: The initialization vector to use for the decryption - * - * Returns the number of bytes decrypted; negative value on error - */ -static int decrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat, - struct scatterlist *dest_sg, - struct scatterlist *src_sg, int size, - unsigned char *iv) -{ - struct blkcipher_desc desc = { - .tfm = crypt_stat->tfm, - .info = iv, - .flags = CRYPTO_TFM_REQ_MAY_SLEEP - }; - int rc = 0; - - /* Consider doing this once, when the file is opened */ - mutex_lock(&crypt_stat->cs_tfm_mutex); - rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key, - crypt_stat->key_size); - if (rc) { - ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n", - rc); - mutex_unlock(&crypt_stat->cs_tfm_mutex); - rc = -EINVAL; - goto out; - } - ecryptfs_printk(KERN_DEBUG, "Decrypting [%d] bytes.\n", size); - rc = crypto_blkcipher_decrypt_iv(&desc, dest_sg, src_sg, size); - mutex_unlock(&crypt_stat->cs_tfm_mutex); - if (rc) { - ecryptfs_printk(KERN_ERR, "Error decrypting; rc = [%d]\n", - rc); - goto out; - } - rc = size; -out: return rc; } -/** - * ecryptfs_encrypt_page_offset - * @crypt_stat: The cryptographic context - * @dst_page: The page to encrypt into - * @dst_offset: The offset in the page to encrypt into - * @src_page: The page to encrypt from - * @src_offset: The offset in the page to encrypt from - * @size: The number of bytes to encrypt - * @iv: The initialization vector to use for the encryption - * - * Returns the number of bytes encrypted - */ -static int -ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, - struct page *dst_page, int dst_offset, - struct page *src_page, int src_offset, int size, - unsigned char *iv) -{ - struct scatterlist src_sg, dst_sg; - - sg_init_table(&src_sg, 1); - sg_init_table(&dst_sg, 1); - - sg_set_page(&src_sg, src_page, size, src_offset); - sg_set_page(&dst_sg, dst_page, size, dst_offset); - return encrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv); -} - -/** - * ecryptfs_decrypt_page_offset - * @crypt_stat: The cryptographic context - * @dst_page: The page to decrypt into - * @dst_offset: The offset in the page to decrypt into - * @src_page: The page to decrypt from - * @src_offset: The offset in the page to decrypt from - * @size: The number of bytes to decrypt - * @iv: The initialization vector to use for the decryption - * - * Returns the number of bytes decrypted - */ -static int -ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, - struct page *dst_page, int dst_offset, - struct page *src_page, int src_offset, int size, - unsigned char *iv) -{ - struct scatterlist src_sg, dst_sg; - - sg_init_table(&src_sg, 1); - sg_set_page(&src_sg, src_page, size, src_offset); - - sg_init_table(&dst_sg, 1); - sg_set_page(&dst_sg, dst_page, size, dst_offset); - - return decrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv); -} - #define ECRYPTFS_MAX_SCATTERLIST_LEN 4 /** * ecryptfs_init_crypt_ctx - * @crypt_stat: Uninitilized crypt stats structure + * @crypt_stat: Uninitialized crypt stats structure * * Initialize the crypto context. * @@ -784,39 +609,35 @@ int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat) char *full_alg_name; int rc = -EINVAL; - if (!crypt_stat->cipher) { - ecryptfs_printk(KERN_ERR, "No cipher specified\n"); - goto out; - } ecryptfs_printk(KERN_DEBUG, "Initializing cipher [%s]; strlen = [%d]; " - "key_size_bits = [%d]\n", + "key_size_bits = [%zd]\n", crypt_stat->cipher, (int)strlen(crypt_stat->cipher), crypt_stat->key_size << 3); + mutex_lock(&crypt_stat->cs_tfm_mutex); if (crypt_stat->tfm) { rc = 0; - goto out; + goto out_unlock; } - mutex_lock(&crypt_stat->cs_tfm_mutex); rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, crypt_stat->cipher, "cbc"); if (rc) goto out_unlock; - crypt_stat->tfm = crypto_alloc_blkcipher(full_alg_name, 0, - CRYPTO_ALG_ASYNC); - kfree(full_alg_name); + crypt_stat->tfm = crypto_alloc_ablkcipher(full_alg_name, 0, 0); if (IS_ERR(crypt_stat->tfm)) { rc = PTR_ERR(crypt_stat->tfm); + crypt_stat->tfm = NULL; ecryptfs_printk(KERN_ERR, "cryptfs: init_crypt_ctx(): " "Error initializing cipher [%s]\n", - crypt_stat->cipher); - goto out_unlock; + full_alg_name); + goto out_free; } - crypto_blkcipher_set_flags(crypt_stat->tfm, CRYPTO_TFM_REQ_WEAK_KEY); + crypto_ablkcipher_set_flags(crypt_stat->tfm, CRYPTO_TFM_REQ_WEAK_KEY); rc = 0; +out_free: + kfree(full_alg_name); out_unlock: mutex_unlock(&crypt_stat->cs_tfm_mutex); -out: return rc; } @@ -844,13 +665,13 @@ void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat) set_extent_mask_and_shift(crypt_stat); crypt_stat->iv_bytes = ECRYPTFS_DEFAULT_IV_BYTES; if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) - crypt_stat->num_header_bytes_at_front = 0; + crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; else { if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE) - crypt_stat->num_header_bytes_at_front = + crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; else - crypt_stat->num_header_bytes_at_front = PAGE_CACHE_SIZE; + crypt_stat->metadata_size = PAGE_CACHE_SIZE; } } @@ -917,6 +738,15 @@ static void ecryptfs_copy_mount_wide_flags_to_inode_flags( crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) crypt_stat->flags |= ECRYPTFS_VIEW_AS_ENCRYPTED; + if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) { + crypt_stat->flags |= ECRYPTFS_ENCRYPT_FILENAMES; + if (mount_crypt_stat->flags + & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK) + crypt_stat->flags |= ECRYPTFS_ENCFN_USE_MOUNT_FNEK; + else if (mount_crypt_stat->flags + & ECRYPTFS_GLOBAL_ENCFN_USE_FEK) + crypt_stat->flags |= ECRYPTFS_ENCFN_USE_FEK; + } } static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs( @@ -926,20 +756,24 @@ static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs( struct ecryptfs_global_auth_tok *global_auth_tok; int rc = 0; + mutex_lock(&crypt_stat->keysig_list_mutex); mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); + list_for_each_entry(global_auth_tok, &mount_crypt_stat->global_auth_tok_list, mount_crypt_stat_list) { + if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_FNEK) + continue; rc = ecryptfs_add_keysig(crypt_stat, global_auth_tok->sig); if (rc) { printk(KERN_ERR "Error adding keysig; rc = [%d]\n", rc); - mutex_unlock( - &mount_crypt_stat->global_auth_tok_list_mutex); goto out; } } - mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); + out: + mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); + mutex_unlock(&crypt_stat->keysig_list_mutex); return rc; } @@ -966,7 +800,7 @@ static void ecryptfs_set_default_crypt_stat_vals( /** * ecryptfs_new_file_context - * @ecryptfs_dentry: The eCryptfs dentry + * @ecryptfs_inode: The eCryptfs inode * * If the crypto context for the file has not yet been established, * this is where we do that. Establishing a new crypto context @@ -983,13 +817,13 @@ static void ecryptfs_set_default_crypt_stat_vals( * * Returns zero on success; non-zero otherwise */ -int ecryptfs_new_file_context(struct dentry *ecryptfs_dentry) +int ecryptfs_new_file_context(struct inode *ecryptfs_inode) { struct ecryptfs_crypt_stat *crypt_stat = - &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; + &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; struct ecryptfs_mount_crypt_stat *mount_crypt_stat = &ecryptfs_superblock_to_private( - ecryptfs_dentry->d_sb)->mount_crypt_stat; + ecryptfs_inode->i_sb)->mount_crypt_stat; int cipher_name_len; int rc = 0; @@ -1023,27 +857,25 @@ out: } /** - * contains_ecryptfs_marker - check for the ecryptfs marker + * ecryptfs_validate_marker - check for the ecryptfs marker * @data: The data block in which to check * - * Returns one if marker found; zero if not found + * Returns zero if marker found; -EINVAL if not found */ -static int contains_ecryptfs_marker(char *data) +static int ecryptfs_validate_marker(char *data) { u32 m_1, m_2; - memcpy(&m_1, data, 4); - m_1 = be32_to_cpu(m_1); - memcpy(&m_2, (data + 4), 4); - m_2 = be32_to_cpu(m_2); + m_1 = get_unaligned_be32(data); + m_2 = get_unaligned_be32(data + 4); if ((m_1 ^ MAGIC_ECRYPTFS_MARKER) == m_2) - return 1; + return 0; ecryptfs_printk(KERN_DEBUG, "m_1 = [0x%.8x]; m_2 = [0x%.8x]; " "MAGIC_ECRYPTFS_MARKER = [0x%.8x]\n", m_1, m_2, MAGIC_ECRYPTFS_MARKER); ecryptfs_printk(KERN_DEBUG, "(m_1 ^ MAGIC_ECRYPTFS_MARKER) = " "[0x%.8x]\n", (m_1 ^ MAGIC_ECRYPTFS_MARKER)); - return 0; + return -EINVAL; } struct ecryptfs_flag_map_elem { @@ -1055,7 +887,8 @@ struct ecryptfs_flag_map_elem { static struct ecryptfs_flag_map_elem ecryptfs_flag_map[] = { {0x00000001, ECRYPTFS_ENABLE_HMAC}, {0x00000002, ECRYPTFS_ENCRYPTED}, - {0x00000004, ECRYPTFS_METADATA_IN_XATTR} + {0x00000004, ECRYPTFS_METADATA_IN_XATTR}, + {0x00000008, ECRYPTFS_ENCRYPT_FILENAMES} }; /** @@ -1073,8 +906,7 @@ static int ecryptfs_process_flags(struct ecryptfs_crypt_stat *crypt_stat, int i; u32 flags; - memcpy(&flags, page_virt, 4); - flags = be32_to_cpu(flags); + flags = get_unaligned_be32(page_virt); for (i = 0; i < ((sizeof(ecryptfs_flag_map) / sizeof(struct ecryptfs_flag_map_elem))); i++) if (flags & ecryptfs_flag_map[i].file_flag) { @@ -1100,17 +932,15 @@ static void write_ecryptfs_marker(char *page_virt, size_t *written) get_random_bytes(&m_1, (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); m_2 = (m_1 ^ MAGIC_ECRYPTFS_MARKER); - m_1 = cpu_to_be32(m_1); - memcpy(page_virt, &m_1, (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); - m_2 = cpu_to_be32(m_2); - memcpy(page_virt + (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2), &m_2, - (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2)); + put_unaligned_be32(m_1, page_virt); + page_virt += (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2); + put_unaligned_be32(m_2, page_virt); (*written) = MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; } -static void -write_ecryptfs_flags(char *page_virt, struct ecryptfs_crypt_stat *crypt_stat, - size_t *written) +void ecryptfs_write_crypt_stat_flags(char *page_virt, + struct ecryptfs_crypt_stat *crypt_stat, + size_t *written) { u32 flags = 0; int i; @@ -1121,8 +951,7 @@ write_ecryptfs_flags(char *page_virt, struct ecryptfs_crypt_stat *crypt_stat, flags |= ecryptfs_flag_map[i].file_flag; /* Version is in top 8 bits of the 32-bit flag vector */ flags |= ((((u8)crypt_stat->file_version) << 24) & 0xFF000000); - flags = cpu_to_be32(flags); - memcpy(page_virt, &flags, 4); + put_unaligned_be32(flags, page_virt); (*written) = 4; } @@ -1148,19 +977,20 @@ ecryptfs_cipher_code_str_map[] = { /** * ecryptfs_code_for_cipher_string - * @crypt_stat: The cryptographic context + * @cipher_name: The string alias for the cipher + * @key_bytes: Length of key in bytes; used for AES code selection * * Returns zero on no match, or the cipher code on match */ -u8 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat) +u8 ecryptfs_code_for_cipher_string(char *cipher_name, size_t key_bytes) { int i; u8 code = 0; struct ecryptfs_cipher_code_str_map_elem *map = ecryptfs_cipher_code_str_map; - if (strcmp(crypt_stat->cipher, "aes") == 0) { - switch (crypt_stat->key_size) { + if (strcmp(cipher_name, "aes") == 0) { + switch (key_bytes) { case 16: code = RFC2440_CIPHER_AES_128; break; @@ -1172,7 +1002,7 @@ u8 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat) } } else { for (i = 0; i < ARRAY_SIZE(ecryptfs_cipher_code_str_map); i++) - if (strcmp(crypt_stat->cipher, map[i].cipher_str) == 0){ + if (strcmp(cipher_name, map[i].cipher_str) == 0) { code = map[i].cipher_code; break; } @@ -1204,25 +1034,19 @@ int ecryptfs_cipher_code_to_string(char *str, u8 cipher_code) return rc; } -int ecryptfs_read_and_validate_header_region(char *data, - struct inode *ecryptfs_inode) +int ecryptfs_read_and_validate_header_region(struct inode *inode) { - struct ecryptfs_crypt_stat *crypt_stat = - &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); + u8 file_size[ECRYPTFS_SIZE_AND_MARKER_BYTES]; + u8 *marker = file_size + ECRYPTFS_FILE_SIZE_BYTES; int rc; - rc = ecryptfs_read_lower(data, 0, crypt_stat->extent_size, - ecryptfs_inode); - if (rc) { - printk(KERN_ERR "%s: Error reading header region; rc = [%d]\n", - __FUNCTION__, rc); - goto out; - } - if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) { - rc = -EINVAL; - ecryptfs_printk(KERN_DEBUG, "Valid marker not found\n"); - } -out: + rc = ecryptfs_read_lower(file_size, 0, ECRYPTFS_SIZE_AND_MARKER_BYTES, + inode); + if (rc < ECRYPTFS_SIZE_AND_MARKER_BYTES) + return rc >= 0 ? -EINVAL : rc; + rc = ecryptfs_validate_marker(marker); + if (!rc) + ecryptfs_i_size_init(file_size, inode); return rc; } @@ -1236,23 +1060,19 @@ ecryptfs_write_header_metadata(char *virt, header_extent_size = (u32)crypt_stat->extent_size; num_header_extents_at_front = - (u16)(crypt_stat->num_header_bytes_at_front - / crypt_stat->extent_size); - header_extent_size = cpu_to_be32(header_extent_size); - memcpy(virt, &header_extent_size, 4); + (u16)(crypt_stat->metadata_size / crypt_stat->extent_size); + put_unaligned_be32(header_extent_size, virt); virt += 4; - num_header_extents_at_front = cpu_to_be16(num_header_extents_at_front); - memcpy(virt, &num_header_extents_at_front, 2); + put_unaligned_be16(num_header_extents_at_front, virt); (*written) = 6; } -struct kmem_cache *ecryptfs_header_cache_0; -struct kmem_cache *ecryptfs_header_cache_1; -struct kmem_cache *ecryptfs_header_cache_2; +struct kmem_cache *ecryptfs_header_cache; /** * ecryptfs_write_headers_virt * @page_virt: The virtual address to write the headers to + * @max: The size of memory allocated at page_virt * @size: Set to the number of bytes written by this function * @crypt_stat: The cryptographic context * @ecryptfs_dentry: The eCryptfs dentry @@ -1280,7 +1100,8 @@ struct kmem_cache *ecryptfs_header_cache_2; * * Returns zero on success */ -static int ecryptfs_write_headers_virt(char *page_virt, size_t *size, +static int ecryptfs_write_headers_virt(char *page_virt, size_t max, + size_t *size, struct ecryptfs_crypt_stat *crypt_stat, struct dentry *ecryptfs_dentry) { @@ -1291,14 +1112,15 @@ static int ecryptfs_write_headers_virt(char *page_virt, size_t *size, offset = ECRYPTFS_FILE_SIZE_BYTES; write_ecryptfs_marker((page_virt + offset), &written); offset += written; - write_ecryptfs_flags((page_virt + offset), crypt_stat, &written); + ecryptfs_write_crypt_stat_flags((page_virt + offset), crypt_stat, + &written); offset += written; ecryptfs_write_header_metadata((page_virt + offset), crypt_stat, &written); offset += written; rc = ecryptfs_generate_key_packet_set((page_virt + offset), crypt_stat, ecryptfs_dentry, &written, - PAGE_CACHE_SIZE - offset); + max - offset); if (rc) ecryptfs_printk(KERN_WARNING, "Error generating key packet " "set; rc = [%d]\n", rc); @@ -1310,24 +1132,23 @@ static int ecryptfs_write_headers_virt(char *page_virt, size_t *size, } static int -ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat, - struct dentry *ecryptfs_dentry, - char *virt) +ecryptfs_write_metadata_to_contents(struct inode *ecryptfs_inode, + char *virt, size_t virt_len) { int rc; - rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, virt, - 0, crypt_stat->num_header_bytes_at_front); - if (rc) + rc = ecryptfs_write_lower(ecryptfs_inode, virt, + 0, virt_len); + if (rc < 0) printk(KERN_ERR "%s: Error attempting to write header " - "information to lower file; rc = [%d]\n", __FUNCTION__, - rc); + "information to lower file; rc = [%d]\n", __func__, rc); + else + rc = 0; return rc; } static int ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, - struct ecryptfs_crypt_stat *crypt_stat, char *page_virt, size_t size) { int rc; @@ -1337,9 +1158,21 @@ ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, return rc; } +static unsigned long ecryptfs_get_zeroed_pages(gfp_t gfp_mask, + unsigned int order) +{ + struct page *page; + + page = alloc_pages(gfp_mask | __GFP_ZERO, order); + if (page) + return (unsigned long) page_address(page); + return 0; +} + /** * ecryptfs_write_metadata - * @ecryptfs_dentry: The eCryptfs dentry + * @ecryptfs_dentry: The eCryptfs dentry, which should be negative + * @ecryptfs_inode: The newly created eCryptfs inode * * Write the file headers out. This will likely involve a userspace * callout, in which the session key is encrypted with one or more @@ -1349,11 +1182,14 @@ ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, * * Returns zero on success; non-zero on error */ -int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry) +int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry, + struct inode *ecryptfs_inode) { struct ecryptfs_crypt_stat *crypt_stat = - &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; + &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; + unsigned int order; char *virt; + size_t virt_len; size_t size = 0; int rc = 0; @@ -1365,38 +1201,40 @@ int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry) } } else { printk(KERN_WARNING "%s: Encrypted flag not set\n", - __FUNCTION__); + __func__); rc = -EINVAL; goto out; } + virt_len = crypt_stat->metadata_size; + order = get_order(virt_len); /* Released in this function */ - virt = kzalloc(crypt_stat->num_header_bytes_at_front, GFP_KERNEL); + virt = (char *)ecryptfs_get_zeroed_pages(GFP_KERNEL, order); if (!virt) { - printk(KERN_ERR "%s: Out of memory\n", __FUNCTION__); + printk(KERN_ERR "%s: Out of memory\n", __func__); rc = -ENOMEM; goto out; } - rc = ecryptfs_write_headers_virt(virt, &size, crypt_stat, + /* Zeroed page ensures the in-header unencrypted i_size is set to 0 */ + rc = ecryptfs_write_headers_virt(virt, virt_len, &size, crypt_stat, ecryptfs_dentry); if (unlikely(rc)) { printk(KERN_ERR "%s: Error whilst writing headers; rc = [%d]\n", - __FUNCTION__, rc); + __func__, rc); goto out_free; } if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) - rc = ecryptfs_write_metadata_to_xattr(ecryptfs_dentry, - crypt_stat, virt, size); + rc = ecryptfs_write_metadata_to_xattr(ecryptfs_dentry, virt, + size); else - rc = ecryptfs_write_metadata_to_contents(crypt_stat, - ecryptfs_dentry, virt); + rc = ecryptfs_write_metadata_to_contents(ecryptfs_inode, virt, + virt_len); if (rc) { printk(KERN_ERR "%s: Error writing metadata out to lower file; " - "rc = [%d]\n", __FUNCTION__, rc); + "rc = [%d]\n", __func__, rc); goto out_free; } out_free: - memset(virt, 0, crypt_stat->num_header_bytes_at_front); - kfree(virt); + free_pages((unsigned long)virt, order); out: return rc; } @@ -1411,21 +1249,18 @@ static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat, u32 header_extent_size; u16 num_header_extents_at_front; - memcpy(&header_extent_size, virt, sizeof(u32)); - header_extent_size = be32_to_cpu(header_extent_size); - virt += sizeof(u32); - memcpy(&num_header_extents_at_front, virt, sizeof(u16)); - num_header_extents_at_front = be16_to_cpu(num_header_extents_at_front); - crypt_stat->num_header_bytes_at_front = - (((size_t)num_header_extents_at_front - * (size_t)header_extent_size)); - (*bytes_read) = (sizeof(u32) + sizeof(u16)); + header_extent_size = get_unaligned_be32(virt); + virt += sizeof(__be32); + num_header_extents_at_front = get_unaligned_be16(virt); + crypt_stat->metadata_size = (((size_t)num_header_extents_at_front + * (size_t)header_extent_size)); + (*bytes_read) = (sizeof(__be32) + sizeof(__be16)); if ((validate_header_size == ECRYPTFS_VALIDATE_HEADER_SIZE) - && (crypt_stat->num_header_bytes_at_front + && (crypt_stat->metadata_size < ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)) { rc = -EINVAL; printk(KERN_WARNING "Invalid header size: [%zd]\n", - crypt_stat->num_header_bytes_at_front); + crypt_stat->metadata_size); } return rc; } @@ -1440,8 +1275,26 @@ static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat, */ static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat) { - crypt_stat->num_header_bytes_at_front = - ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; + crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; +} + +void ecryptfs_i_size_init(const char *page_virt, struct inode *inode) +{ + struct ecryptfs_mount_crypt_stat *mount_crypt_stat; + struct ecryptfs_crypt_stat *crypt_stat; + u64 file_size; + + crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; + mount_crypt_stat = + &ecryptfs_superblock_to_private(inode->i_sb)->mount_crypt_stat; + if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) { + file_size = i_size_read(ecryptfs_inode_to_lower(inode)); + if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) + file_size += crypt_stat->metadata_size; + } else + file_size = get_unaligned_be64(page_virt); + i_size_write(inode, (loff_t)file_size); + crypt_stat->flags |= ECRYPTFS_I_SIZE_INITIALIZED; } /** @@ -1469,11 +1322,11 @@ static int ecryptfs_read_headers_virt(char *page_virt, crypt_stat->mount_crypt_stat = &ecryptfs_superblock_to_private( ecryptfs_dentry->d_sb)->mount_crypt_stat; offset = ECRYPTFS_FILE_SIZE_BYTES; - rc = contains_ecryptfs_marker(page_virt + offset); - if (rc == 0) { - rc = -EINVAL; + rc = ecryptfs_validate_marker(page_virt + offset); + if (rc) goto out; - } + if (!(crypt_stat->flags & ECRYPTFS_I_SIZE_INITIALIZED)) + ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode); offset += MAGIC_ECRYPTFS_MARKER_SIZE_BYTES; rc = ecryptfs_process_flags(crypt_stat, (page_virt + offset), &bytes_read); @@ -1538,20 +1391,21 @@ out: return rc; } -int ecryptfs_read_and_validate_xattr_region(char *page_virt, - struct dentry *ecryptfs_dentry) +int ecryptfs_read_and_validate_xattr_region(struct dentry *dentry, + struct inode *inode) { + u8 file_size[ECRYPTFS_SIZE_AND_MARKER_BYTES]; + u8 *marker = file_size + ECRYPTFS_FILE_SIZE_BYTES; int rc; - rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_dentry->d_inode); - if (rc) - goto out; - if (!contains_ecryptfs_marker(page_virt + ECRYPTFS_FILE_SIZE_BYTES)) { - printk(KERN_WARNING "Valid data found in [%s] xattr, but " - "the marker is invalid\n", ECRYPTFS_XATTR_NAME); - rc = -EINVAL; - } -out: + rc = ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), + ECRYPTFS_XATTR_NAME, file_size, + ECRYPTFS_SIZE_AND_MARKER_BYTES); + if (rc < ECRYPTFS_SIZE_AND_MARKER_BYTES) + return rc >= 0 ? -EINVAL : rc; + rc = ecryptfs_validate_marker(marker); + if (!rc) + ecryptfs_i_size_init(file_size, inode); return rc; } @@ -1569,8 +1423,8 @@ out: */ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry) { - int rc = 0; - char *page_virt = NULL; + int rc; + char *page_virt; struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode; struct ecryptfs_crypt_stat *crypt_stat = &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; @@ -1581,24 +1435,27 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry) ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, mount_crypt_stat); /* Read the first page from the underlying file */ - page_virt = kmem_cache_alloc(ecryptfs_header_cache_1, GFP_USER); + page_virt = kmem_cache_alloc(ecryptfs_header_cache, GFP_USER); if (!page_virt) { rc = -ENOMEM; printk(KERN_ERR "%s: Unable to allocate page_virt\n", - __FUNCTION__); + __func__); goto out; } rc = ecryptfs_read_lower(page_virt, 0, crypt_stat->extent_size, ecryptfs_inode); - if (!rc) + if (rc >= 0) rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, ecryptfs_dentry, ECRYPTFS_VALIDATE_HEADER_SIZE); if (rc) { + /* metadata is not in the file header, so try xattrs */ + memset(page_virt, 0, PAGE_CACHE_SIZE); rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_inode); if (rc) { printk(KERN_DEBUG "Valid eCryptfs headers not found in " - "file header region or xattr region\n"); + "file header region or xattr region, inode %lu\n", + ecryptfs_inode->i_ino); rc = -EINVAL; goto out; } @@ -1607,7 +1464,8 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry) ECRYPTFS_DONT_VALIDATE_HEADER_SIZE); if (rc) { printk(KERN_DEBUG "Valid eCryptfs headers not found in " - "file xattr region either\n"); + "file xattr region either, inode %lu\n", + ecryptfs_inode->i_ino); rc = -EINVAL; } if (crypt_stat->mount_crypt_stat->flags @@ -1618,108 +1476,109 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry) "crypto metadata only in the extended attribute " "region, but eCryptfs was mounted without " "xattr support enabled. eCryptfs will not treat " - "this like an encrypted file.\n"); + "this like an encrypted file, inode %lu\n", + ecryptfs_inode->i_ino); rc = -EINVAL; } } out: if (page_virt) { memset(page_virt, 0, PAGE_CACHE_SIZE); - kmem_cache_free(ecryptfs_header_cache_1, page_virt); + kmem_cache_free(ecryptfs_header_cache, page_virt); } return rc; } /** - * ecryptfs_encode_filename - converts a plaintext file name to cipher text - * @crypt_stat: The crypt_stat struct associated with the file anem to encode - * @name: The plaintext name - * @length: The length of the plaintext - * @encoded_name: The encypted name + * ecryptfs_encrypt_filename - encrypt filename * - * Encrypts and encodes a filename into something that constitutes a - * valid filename for a filesystem, with printable characters. + * CBC-encrypts the filename. We do not want to encrypt the same + * filename with the same key and IV, which may happen with hard + * links, so we prepend random bits to each filename. * - * We assume that we have a properly initialized crypto context, - * pointed to by crypt_stat->tfm. - * - * TODO: Implement filename decoding and decryption here, in place of - * memcpy. We are keeping the framework around for now to (1) - * facilitate testing of the components needed to implement filename - * encryption and (2) to provide a code base from which other - * developers in the community can easily implement this feature. - * - * Returns the length of encoded filename; negative if error + * Returns zero on success; non-zero otherwise */ -int -ecryptfs_encode_filename(struct ecryptfs_crypt_stat *crypt_stat, - const char *name, int length, char **encoded_name) +static int +ecryptfs_encrypt_filename(struct ecryptfs_filename *filename, + struct ecryptfs_crypt_stat *crypt_stat, + struct ecryptfs_mount_crypt_stat *mount_crypt_stat) { - int error = 0; + int rc = 0; - (*encoded_name) = kmalloc(length + 2, GFP_KERNEL); - if (!(*encoded_name)) { - error = -ENOMEM; + filename->encrypted_filename = NULL; + filename->encrypted_filename_size = 0; + if ((crypt_stat && (crypt_stat->flags & ECRYPTFS_ENCFN_USE_MOUNT_FNEK)) + || (mount_crypt_stat && (mount_crypt_stat->flags + & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK))) { + size_t packet_size; + size_t remaining_bytes; + + rc = ecryptfs_write_tag_70_packet( + NULL, NULL, + &filename->encrypted_filename_size, + mount_crypt_stat, NULL, + filename->filename_size); + if (rc) { + printk(KERN_ERR "%s: Error attempting to get packet " + "size for tag 72; rc = [%d]\n", __func__, + rc); + filename->encrypted_filename_size = 0; + goto out; + } + filename->encrypted_filename = + kmalloc(filename->encrypted_filename_size, GFP_KERNEL); + if (!filename->encrypted_filename) { + printk(KERN_ERR "%s: Out of memory whilst attempting " + "to kmalloc [%zd] bytes\n", __func__, + filename->encrypted_filename_size); + rc = -ENOMEM; + goto out; + } + remaining_bytes = filename->encrypted_filename_size; + rc = ecryptfs_write_tag_70_packet(filename->encrypted_filename, + &remaining_bytes, + &packet_size, + mount_crypt_stat, + filename->filename, + filename->filename_size); + if (rc) { + printk(KERN_ERR "%s: Error attempting to generate " + "tag 70 packet; rc = [%d]\n", __func__, + rc); + kfree(filename->encrypted_filename); + filename->encrypted_filename = NULL; + filename->encrypted_filename_size = 0; + goto out; + } + filename->encrypted_filename_size = packet_size; + } else { + printk(KERN_ERR "%s: No support for requested filename " + "encryption method in this release\n", __func__); + rc = -EOPNOTSUPP; goto out; } - /* TODO: Filename encryption is a scheduled feature for a - * future version of eCryptfs. This function is here only for - * the purpose of providing a framework for other developers - * to easily implement filename encryption. Hint: Replace this - * memcpy() with a call to encrypt and encode the - * filename, the set the length accordingly. */ - memcpy((void *)(*encoded_name), (void *)name, length); - (*encoded_name)[length] = '\0'; - error = length + 1; out: - return error; + return rc; } -/** - * ecryptfs_decode_filename - converts the cipher text name to plaintext - * @crypt_stat: The crypt_stat struct associated with the file - * @name: The filename in cipher text - * @length: The length of the cipher text name - * @decrypted_name: The plaintext name - * - * Decodes and decrypts the filename. - * - * We assume that we have a properly initialized crypto context, - * pointed to by crypt_stat->tfm. - * - * TODO: Implement filename decoding and decryption here, in place of - * memcpy. We are keeping the framework around for now to (1) - * facilitate testing of the components needed to implement filename - * encryption and (2) to provide a code base from which other - * developers in the community can easily implement this feature. - * - * Returns the length of decoded filename; negative if error - */ -int -ecryptfs_decode_filename(struct ecryptfs_crypt_stat *crypt_stat, - const char *name, int length, char **decrypted_name) +static int ecryptfs_copy_filename(char **copied_name, size_t *copied_name_size, + const char *name, size_t name_size) { - int error = 0; + int rc = 0; - (*decrypted_name) = kmalloc(length + 2, GFP_KERNEL); - if (!(*decrypted_name)) { - error = -ENOMEM; + (*copied_name) = kmalloc((name_size + 1), GFP_KERNEL); + if (!(*copied_name)) { + rc = -ENOMEM; goto out; } - /* TODO: Filename encryption is a scheduled feature for a - * future version of eCryptfs. This function is here only for - * the purpose of providing a framework for other developers - * to easily implement filename encryption. Hint: Replace this - * memcpy() with a call to decode and decrypt the - * filename, the set the length accordingly. */ - memcpy((void *)(*decrypted_name), (void *)name, length); - (*decrypted_name)[length + 1] = '\0'; /* Only for convenience + memcpy((void *)(*copied_name), (void *)name, name_size); + (*copied_name)[(name_size)] = '\0'; /* Only for convenience * in printing out the * string in debug * messages */ - error = length; + (*copied_name_size) = name_size; out: - return error; + return rc; } /** @@ -1737,13 +1596,13 @@ ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm, char *cipher_name, size_t *key_size) { char dummy_key[ECRYPTFS_MAX_KEY_BYTES]; - char *full_alg_name; + char *full_alg_name = NULL; int rc; *key_tfm = NULL; if (*key_size > ECRYPTFS_MAX_KEY_BYTES) { rc = -EINVAL; - printk(KERN_ERR "Requested key size is [%Zd] bytes; maximum " + printk(KERN_ERR "Requested key size is [%zd] bytes; maximum " "allowable is [%d]\n", *key_size, ECRYPTFS_MAX_KEY_BYTES); goto out; } @@ -1752,11 +1611,10 @@ ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm, if (rc) goto out; *key_tfm = crypto_alloc_blkcipher(full_alg_name, 0, CRYPTO_ALG_ASYNC); - kfree(full_alg_name); if (IS_ERR(*key_tfm)) { rc = PTR_ERR(*key_tfm); printk(KERN_ERR "Unable to allocate crypto cipher with name " - "[%s]; rc = [%d]\n", cipher_name, rc); + "[%s]; rc = [%d]\n", full_alg_name, rc); goto out; } crypto_blkcipher_set_flags(*key_tfm, CRYPTO_TFM_REQ_WEAK_KEY); @@ -1768,12 +1626,14 @@ ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm, get_random_bytes(dummy_key, *key_size); rc = crypto_blkcipher_setkey(*key_tfm, dummy_key, *key_size); if (rc) { - printk(KERN_ERR "Error attempting to set key of size [%Zd] for " - "cipher [%s]; rc = [%d]\n", *key_size, cipher_name, rc); + printk(KERN_ERR "Error attempting to set key of size [%zd] for " + "cipher [%s]; rc = [%d]\n", *key_size, full_alg_name, + rc); rc = -EINVAL; goto out; } out: + kfree(full_alg_name); return rc; } @@ -1781,7 +1641,7 @@ struct kmem_cache *ecryptfs_key_tfm_cache; static struct list_head key_tfm_list; struct mutex key_tfm_list_mutex; -int ecryptfs_init_crypto(void) +int __init ecryptfs_init_crypto(void) { mutex_init(&key_tfm_list_mutex); INIT_LIST_HEAD(&key_tfm_list); @@ -1907,9 +1767,401 @@ int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm, goto out; } } - mutex_unlock(&key_tfm_list_mutex); (*tfm) = key_tfm->key_tfm; (*tfm_mutex) = &key_tfm->key_tfm_mutex; out: + mutex_unlock(&key_tfm_list_mutex); return rc; } + +/* 64 characters forming a 6-bit target field */ +static unsigned char *portable_filename_chars = ("-.0123456789ABCD" + "EFGHIJKLMNOPQRST" + "UVWXYZabcdefghij" + "klmnopqrstuvwxyz"); + +/* We could either offset on every reverse map or just pad some 0x00's + * at the front here */ +static const unsigned char filename_rev_map[256] = { + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 7 */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 15 */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 23 */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 31 */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 39 */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, /* 47 */ + 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, /* 55 */ + 0x0A, 0x0B, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 63 */ + 0x00, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, /* 71 */ + 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, /* 79 */ + 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, /* 87 */ + 0x23, 0x24, 0x25, 0x00, 0x00, 0x00, 0x00, 0x00, /* 95 */ + 0x00, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, /* 103 */ + 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, /* 111 */ + 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, /* 119 */ + 0x3D, 0x3E, 0x3F /* 123 - 255 initialized to 0x00 */ +}; + +/** + * ecryptfs_encode_for_filename + * @dst: Destination location for encoded filename + * @dst_size: Size of the encoded filename in bytes + * @src: Source location for the filename to encode + * @src_size: Size of the source in bytes + */ +static void ecryptfs_encode_for_filename(unsigned char *dst, size_t *dst_size, + unsigned char *src, size_t src_size) +{ + size_t num_blocks; + size_t block_num = 0; + size_t dst_offset = 0; + unsigned char last_block[3]; + + if (src_size == 0) { + (*dst_size) = 0; + goto out; + } + num_blocks = (src_size / 3); + if ((src_size % 3) == 0) { + memcpy(last_block, (&src[src_size - 3]), 3); + } else { + num_blocks++; + last_block[2] = 0x00; + switch (src_size % 3) { + case 1: + last_block[0] = src[src_size - 1]; + last_block[1] = 0x00; + break; + case 2: + last_block[0] = src[src_size - 2]; + last_block[1] = src[src_size - 1]; + } + } + (*dst_size) = (num_blocks * 4); + if (!dst) + goto out; + while (block_num < num_blocks) { + unsigned char *src_block; + unsigned char dst_block[4]; + + if (block_num == (num_blocks - 1)) + src_block = last_block; + else + src_block = &src[block_num * 3]; + dst_block[0] = ((src_block[0] >> 2) & 0x3F); + dst_block[1] = (((src_block[0] << 4) & 0x30) + | ((src_block[1] >> 4) & 0x0F)); + dst_block[2] = (((src_block[1] << 2) & 0x3C) + | ((src_block[2] >> 6) & 0x03)); + dst_block[3] = (src_block[2] & 0x3F); + dst[dst_offset++] = portable_filename_chars[dst_block[0]]; + dst[dst_offset++] = portable_filename_chars[dst_block[1]]; + dst[dst_offset++] = portable_filename_chars[dst_block[2]]; + dst[dst_offset++] = portable_filename_chars[dst_block[3]]; + block_num++; + } +out: + return; +} + +static size_t ecryptfs_max_decoded_size(size_t encoded_size) +{ + /* Not exact; conservatively long. Every block of 4 + * encoded characters decodes into a block of 3 + * decoded characters. This segment of code provides + * the caller with the maximum amount of allocated + * space that @dst will need to point to in a + * subsequent call. */ + return ((encoded_size + 1) * 3) / 4; +} + +/** + * ecryptfs_decode_from_filename + * @dst: If NULL, this function only sets @dst_size and returns. If + * non-NULL, this function decodes the encoded octets in @src + * into the memory that @dst points to. + * @dst_size: Set to the size of the decoded string. + * @src: The encoded set of octets to decode. + * @src_size: The size of the encoded set of octets to decode. + */ +static void +ecryptfs_decode_from_filename(unsigned char *dst, size_t *dst_size, + const unsigned char *src, size_t src_size) +{ + u8 current_bit_offset = 0; + size_t src_byte_offset = 0; + size_t dst_byte_offset = 0; + + if (dst == NULL) { + (*dst_size) = ecryptfs_max_decoded_size(src_size); + goto out; + } + while (src_byte_offset < src_size) { + unsigned char src_byte = + filename_rev_map[(int)src[src_byte_offset]]; + + switch (current_bit_offset) { + case 0: + dst[dst_byte_offset] = (src_byte << 2); + current_bit_offset = 6; + break; + case 6: + dst[dst_byte_offset++] |= (src_byte >> 4); + dst[dst_byte_offset] = ((src_byte & 0xF) + << 4); + current_bit_offset = 4; + break; + case 4: + dst[dst_byte_offset++] |= (src_byte >> 2); + dst[dst_byte_offset] = (src_byte << 6); + current_bit_offset = 2; + break; + case 2: + dst[dst_byte_offset++] |= (src_byte); + dst[dst_byte_offset] = 0; + current_bit_offset = 0; + break; + } + src_byte_offset++; + } + (*dst_size) = dst_byte_offset; +out: + return; +} + +/** + * ecryptfs_encrypt_and_encode_filename - converts a plaintext file name to cipher text + * @crypt_stat: The crypt_stat struct associated with the file anem to encode + * @name: The plaintext name + * @length: The length of the plaintext + * @encoded_name: The encypted name + * + * Encrypts and encodes a filename into something that constitutes a + * valid filename for a filesystem, with printable characters. + * + * We assume that we have a properly initialized crypto context, + * pointed to by crypt_stat->tfm. + * + * Returns zero on success; non-zero on otherwise + */ +int ecryptfs_encrypt_and_encode_filename( + char **encoded_name, + size_t *encoded_name_size, + struct ecryptfs_crypt_stat *crypt_stat, + struct ecryptfs_mount_crypt_stat *mount_crypt_stat, + const char *name, size_t name_size) +{ + size_t encoded_name_no_prefix_size; + int rc = 0; + + (*encoded_name) = NULL; + (*encoded_name_size) = 0; + if ((crypt_stat && (crypt_stat->flags & ECRYPTFS_ENCRYPT_FILENAMES)) + || (mount_crypt_stat && (mount_crypt_stat->flags + & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES))) { + struct ecryptfs_filename *filename; + + filename = kzalloc(sizeof(*filename), GFP_KERNEL); + if (!filename) { + printk(KERN_ERR "%s: Out of memory whilst attempting " + "to kzalloc [%zd] bytes\n", __func__, + sizeof(*filename)); + rc = -ENOMEM; + goto out; + } + filename->filename = (char *)name; + filename->filename_size = name_size; + rc = ecryptfs_encrypt_filename(filename, crypt_stat, + mount_crypt_stat); + if (rc) { + printk(KERN_ERR "%s: Error attempting to encrypt " + "filename; rc = [%d]\n", __func__, rc); + kfree(filename); + goto out; + } + ecryptfs_encode_for_filename( + NULL, &encoded_name_no_prefix_size, + filename->encrypted_filename, + filename->encrypted_filename_size); + if ((crypt_stat && (crypt_stat->flags + & ECRYPTFS_ENCFN_USE_MOUNT_FNEK)) + || (mount_crypt_stat + && (mount_crypt_stat->flags + & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK))) + (*encoded_name_size) = + (ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE + + encoded_name_no_prefix_size); + else + (*encoded_name_size) = + (ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX_SIZE + + encoded_name_no_prefix_size); + (*encoded_name) = kmalloc((*encoded_name_size) + 1, GFP_KERNEL); + if (!(*encoded_name)) { + printk(KERN_ERR "%s: Out of memory whilst attempting " + "to kzalloc [%zd] bytes\n", __func__, + (*encoded_name_size)); + rc = -ENOMEM; + kfree(filename->encrypted_filename); + kfree(filename); + goto out; + } + if ((crypt_stat && (crypt_stat->flags + & ECRYPTFS_ENCFN_USE_MOUNT_FNEK)) + || (mount_crypt_stat + && (mount_crypt_stat->flags + & ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK))) { + memcpy((*encoded_name), + ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX, + ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE); + ecryptfs_encode_for_filename( + ((*encoded_name) + + ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE), + &encoded_name_no_prefix_size, + filename->encrypted_filename, + filename->encrypted_filename_size); + (*encoded_name_size) = + (ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE + + encoded_name_no_prefix_size); + (*encoded_name)[(*encoded_name_size)] = '\0'; + } else { + rc = -EOPNOTSUPP; + } + if (rc) { + printk(KERN_ERR "%s: Error attempting to encode " + "encrypted filename; rc = [%d]\n", __func__, + rc); + kfree((*encoded_name)); + (*encoded_name) = NULL; + (*encoded_name_size) = 0; + } + kfree(filename->encrypted_filename); + kfree(filename); + } else { + rc = ecryptfs_copy_filename(encoded_name, + encoded_name_size, + name, name_size); + } +out: + return rc; +} + +/** + * ecryptfs_decode_and_decrypt_filename - converts the encoded cipher text name to decoded plaintext + * @plaintext_name: The plaintext name + * @plaintext_name_size: The plaintext name size + * @ecryptfs_dir_dentry: eCryptfs directory dentry + * @name: The filename in cipher text + * @name_size: The cipher text name size + * + * Decrypts and decodes the filename. + * + * Returns zero on error; non-zero otherwise + */ +int ecryptfs_decode_and_decrypt_filename(char **plaintext_name, + size_t *plaintext_name_size, + struct super_block *sb, + const char *name, size_t name_size) +{ + struct ecryptfs_mount_crypt_stat *mount_crypt_stat = + &ecryptfs_superblock_to_private(sb)->mount_crypt_stat; + char *decoded_name; + size_t decoded_name_size; + size_t packet_size; + int rc = 0; + + if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) + && !(mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) + && (name_size > ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE) + && (strncmp(name, ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX, + ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE) == 0)) { + const char *orig_name = name; + size_t orig_name_size = name_size; + + name += ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE; + name_size -= ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE; + ecryptfs_decode_from_filename(NULL, &decoded_name_size, + name, name_size); + decoded_name = kmalloc(decoded_name_size, GFP_KERNEL); + if (!decoded_name) { + printk(KERN_ERR "%s: Out of memory whilst attempting " + "to kmalloc [%zd] bytes\n", __func__, + decoded_name_size); + rc = -ENOMEM; + goto out; + } + ecryptfs_decode_from_filename(decoded_name, &decoded_name_size, + name, name_size); + rc = ecryptfs_parse_tag_70_packet(plaintext_name, + plaintext_name_size, + &packet_size, + mount_crypt_stat, + decoded_name, + decoded_name_size); + if (rc) { + printk(KERN_INFO "%s: Could not parse tag 70 packet " + "from filename; copying through filename " + "as-is\n", __func__); + rc = ecryptfs_copy_filename(plaintext_name, + plaintext_name_size, + orig_name, orig_name_size); + goto out_free; + } + } else { + rc = ecryptfs_copy_filename(plaintext_name, + plaintext_name_size, + name, name_size); + goto out; + } +out_free: + kfree(decoded_name); +out: + return rc; +} + +#define ENC_NAME_MAX_BLOCKLEN_8_OR_16 143 + +int ecryptfs_set_f_namelen(long *namelen, long lower_namelen, + struct ecryptfs_mount_crypt_stat *mount_crypt_stat) +{ + struct blkcipher_desc desc; + struct mutex *tfm_mutex; + size_t cipher_blocksize; + int rc; + + if (!(mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)) { + (*namelen) = lower_namelen; + return 0; + } + + rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex, + mount_crypt_stat->global_default_fn_cipher_name); + if (unlikely(rc)) { + (*namelen) = 0; + return rc; + } + + mutex_lock(tfm_mutex); + cipher_blocksize = crypto_blkcipher_blocksize(desc.tfm); + mutex_unlock(tfm_mutex); + + /* Return an exact amount for the common cases */ + if (lower_namelen == NAME_MAX + && (cipher_blocksize == 8 || cipher_blocksize == 16)) { + (*namelen) = ENC_NAME_MAX_BLOCKLEN_8_OR_16; + return 0; + } + + /* Return a safe estimate for the uncommon cases */ + (*namelen) = lower_namelen; + (*namelen) -= ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE; + /* Since this is the max decoded size, subtract 1 "decoded block" len */ + (*namelen) = ecryptfs_max_decoded_size(*namelen) - 3; + (*namelen) -= ECRYPTFS_TAG_70_MAX_METADATA_SIZE; + (*namelen) -= ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES; + /* Worst case is that the filename is padded nearly a full block size */ + (*namelen) -= cipher_blocksize - 1; + + if ((*namelen) < 0) + (*namelen) = 0; + + return 0; +} |