diff options
| -rw-r--r-- | fs/ecryptfs/crypto.c | 11 | ||||
| -rw-r--r-- | fs/ecryptfs/ecryptfs_kernel.h | 38 | ||||
| -rw-r--r-- | fs/ecryptfs/keystore.c | 634 |
3 files changed, 613 insertions, 70 deletions
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index 6046239465a1..485732751f09 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -1149,19 +1149,20 @@ 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; @@ -1173,7 +1174,7 @@ 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; } diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index a75026d35d16..76a95bd8819b 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -199,6 +199,7 @@ ecryptfs_get_key_payload_data(struct key *key) #define ECRYPTFS_DEFAULT_CIPHER "aes" #define ECRYPTFS_DEFAULT_KEY_BYTES 16 #define ECRYPTFS_DEFAULT_HASH "md5" +#define ECRYPTFS_TAG_70_DIGEST ECRYPTFS_DEFAULT_HASH #define ECRYPTFS_TAG_1_PACKET_TYPE 0x01 #define ECRYPTFS_TAG_3_PACKET_TYPE 0x8C #define ECRYPTFS_TAG_11_PACKET_TYPE 0xED @@ -206,7 +207,25 @@ ecryptfs_get_key_payload_data(struct key *key) #define ECRYPTFS_TAG_65_PACKET_TYPE 0x41 #define ECRYPTFS_TAG_66_PACKET_TYPE 0x42 #define ECRYPTFS_TAG_67_PACKET_TYPE 0x43 +#define ECRYPTFS_TAG_70_PACKET_TYPE 0x46 /* FNEK-encrypted filename + * as dentry name */ +#define ECRYPTFS_TAG_71_PACKET_TYPE 0x47 /* FNEK-encrypted filename in + * metadata */ +#define ECRYPTFS_TAG_72_PACKET_TYPE 0x48 /* FEK-encrypted filename as + * dentry name */ +#define ECRYPTFS_TAG_73_PACKET_TYPE 0x49 /* FEK-encrypted filename as + * metadata */ +/* Constraint: ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES >= + * ECRYPTFS_MAX_IV_BYTES */ +#define ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES 16 +#define ECRYPTFS_NON_NULL 0x42 /* A reasonable substitute for NULL */ #define MD5_DIGEST_SIZE 16 +#define ECRYPTFS_TAG_70_DIGEST_SIZE MD5_DIGEST_SIZE +#define ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX "ECRYPTFS_FEK_ENCRYPTED." +#define ECRYPTFS_FEK_ENCRYPTED_FILENAME_PREFIX_SIZE 23 +#define ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX "ECRYPTFS_FNEK_ENCRYPTED." +#define ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE 24 +#define ECRYPTFS_ENCRYPTED_DENTRY_NAME_LEN (18 + 1 + 4 + 1 + 32) struct ecryptfs_key_sig { struct list_head crypt_stat_list; @@ -332,13 +351,20 @@ struct ecryptfs_mount_crypt_stat { #define ECRYPTFS_XATTR_METADATA_ENABLED 0x00000002 #define ECRYPTFS_ENCRYPTED_VIEW_ENABLED 0x00000004 #define ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED 0x00000008 +#define ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES 0x00000010 +#define ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK 0x00000020 +#define ECRYPTFS_GLOBAL_ENCFN_USE_FEK 0x00000040 u32 flags; struct list_head global_auth_tok_list; struct mutex global_auth_tok_list_mutex; size_t num_global_auth_toks; size_t global_default_cipher_key_size; + size_t global_default_fn_cipher_key_bytes; unsigned char global_default_cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1]; + unsigned char global_default_fn_cipher_name[ + ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1]; + char global_default_fnek_sig[ECRYPTFS_SIG_SIZE_HEX + 1]; }; /* superblock private data. */ @@ -599,7 +625,7 @@ int ecryptfs_read_and_validate_header_region(char *data, struct inode *ecryptfs_inode); int ecryptfs_read_and_validate_xattr_region(char *page_virt, struct dentry *ecryptfs_dentry); -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 ecryptfs_cipher_code_to_string(char *str, u8 cipher_code); void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat); int ecryptfs_generate_key_packet_set(char *dest_base, @@ -694,5 +720,15 @@ int ecryptfs_privileged_open(struct file **lower_file, struct vfsmount *lower_mnt, const struct cred *cred); int ecryptfs_init_persistent_file(struct dentry *ecryptfs_dentry); +int +ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, + size_t *packet_size, + struct ecryptfs_mount_crypt_stat *mount_crypt_stat, + char *filename, size_t filename_size); +int +ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, + size_t *packet_size, + struct ecryptfs_mount_crypt_stat *mount_crypt_stat, + char *data, size_t max_packet_size); #endif /* #ifndef ECRYPTFS_KERNEL_H */ diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c index 0d713b691941..dafceb5560e5 100644 --- a/fs/ecryptfs/keystore.c +++ b/fs/ecryptfs/keystore.c @@ -403,6 +403,569 @@ out: } static int +ecryptfs_find_global_auth_tok_for_sig( + struct ecryptfs_global_auth_tok **global_auth_tok, + struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig) +{ + struct ecryptfs_global_auth_tok *walker; + int rc = 0; + + (*global_auth_tok) = NULL; + mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); + list_for_each_entry(walker, + &mount_crypt_stat->global_auth_tok_list, + mount_crypt_stat_list) { + if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX) == 0) { + (*global_auth_tok) = walker; + goto out; + } + } + rc = -EINVAL; +out: + mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); + return rc; +} + +/** + * ecryptfs_find_auth_tok_for_sig + * @auth_tok: Set to the matching auth_tok; NULL if not found + * @crypt_stat: inode crypt_stat crypto context + * @sig: Sig of auth_tok to find + * + * For now, this function simply looks at the registered auth_tok's + * linked off the mount_crypt_stat, so all the auth_toks that can be + * used must be registered at mount time. This function could + * potentially try a lot harder to find auth_tok's (e.g., by calling + * out to ecryptfsd to dynamically retrieve an auth_tok object) so + * that static registration of auth_tok's will no longer be necessary. + * + * Returns zero on no error; non-zero on error + */ +static int +ecryptfs_find_auth_tok_for_sig( + struct ecryptfs_auth_tok **auth_tok, + struct ecryptfs_mount_crypt_stat *mount_crypt_stat, + char *sig) +{ + struct ecryptfs_global_auth_tok *global_auth_tok; + int rc = 0; + + (*auth_tok) = NULL; + if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok, + mount_crypt_stat, sig)) { + struct key *auth_tok_key; + + rc = ecryptfs_keyring_auth_tok_for_sig(&auth_tok_key, auth_tok, + sig); + } else + (*auth_tok) = global_auth_tok->global_auth_tok; + return rc; +} + +/** + * write_tag_70_packet can gobble a lot of stack space. We stuff most + * of the function's parameters in a kmalloc'd struct to help reduce + * eCryptfs' overall stack usage. + */ +struct ecryptfs_write_tag_70_packet_silly_stack { + u8 cipher_code; + size_t max_packet_size; + size_t packet_size_len; + size_t block_aligned_filename_size; + size_t block_size; + size_t i; + size_t j; + size_t num_rand_bytes; + struct mutex *tfm_mutex; + char *block_aligned_filename; + struct ecryptfs_auth_tok *auth_tok; + struct scatterlist src_sg; + struct scatterlist dst_sg; + struct blkcipher_desc desc; + char iv[ECRYPTFS_MAX_IV_BYTES]; + char hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; + char tmp_hash[ECRYPTFS_TAG_70_DIGEST_SIZE]; + struct hash_desc hash_desc; + struct scatterlist hash_sg; +}; + +/** + * write_tag_70_packet - Write encrypted filename (EFN) packet against FNEK + * @filename: NULL-terminated filename string + * + * This is the simplest mechanism for achieving filename encryption in + * eCryptfs. It encrypts the given filename with the mount-wide + * filename encryption key (FNEK) and stores it in a packet to @dest, + * which the callee will encode and write directly into the dentry + * name. + */ +int +ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes, + size_t *packet_size, + struct ecryptfs_mount_crypt_stat *mount_crypt_stat, + char *filename, size_t filename_size) +{ + struct ecryptfs_write_tag_70_packet_silly_stack *s; + int rc = 0; + + s = kmalloc(sizeof(*s), GFP_KERNEL); + if (!s) { + printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc " + "[%d] bytes of kernel memory\n", __func__, sizeof(*s)); + goto out; + } + s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; + (*packet_size) = 0; + rc = ecryptfs_get_tfm_and_mutex_for_cipher_name( + &s->desc.tfm, + &s->tfm_mutex, mount_crypt_stat->global_default_fn_cipher_name); + if (unlikely(rc)) { + printk(KERN_ERR "Internal error whilst attempting to get " + "tfm and mutex for cipher name [%s]; rc = [%d]\n", + mount_crypt_stat->global_default_fn_cipher_name, rc); + goto out; + } + mutex_lock(s->tfm_mutex); + s->block_size = crypto_blkcipher_blocksize(s->desc.tfm); + /* Plus one for the \0 separator between the random prefix + * and the plaintext filename */ + s->num_rand_bytes = (ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + 1); + s->block_aligned_filename_size = (s->num_rand_bytes + filename_size); + if ((s->block_aligned_filename_size % s->block_size) != 0) { + s->num_rand_bytes += (s->block_size + - (s->block_aligned_filename_size + % s->block_size)); + s->block_aligned_filename_size = (s->num_rand_bytes + + filename_size); + } + /* Octet 0: Tag 70 identifier + * Octets 1-N1: Tag 70 packet size (includes cipher identifier + * and block-aligned encrypted filename size) + * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE) + * Octet N2-N3: Cipher identifier (1 octet) + * Octets N3-N4: Block-aligned encrypted filename + * - Consists of a minimum number of random characters, a \0 + * separator, and then the filename */ + s->max_packet_size = (1 /* Tag 70 identifier */ + + 3 /* Max Tag 70 packet size */ + + ECRYPTFS_SIG_SIZE /* FNEK sig */ + + 1 /* Cipher identifier */ + + s->block_aligned_filename_size); + if (dest == NULL) { + (*packet_size) = s->max_packet_size; + goto out_unlock; + } + if (s->max_packet_size > (*remaining_bytes)) { + printk(KERN_WARNING "%s: Require [%d] bytes to write; only " + "[%d] available\n", __func__, s->max_packet_size, + (*remaining_bytes)); + rc = -EINVAL; + goto out_unlock; + } + s->block_aligned_filename = kzalloc(s->block_aligned_filename_size, + GFP_KERNEL); + if (!s->block_aligned_filename) { + printk(KERN_ERR "%s: Out of kernel memory whilst attempting to " + "kzalloc [%Zd] bytes\n", __func__, + s->block_aligned_filename_size); + rc = -ENOMEM; + goto out_unlock; + } + s->i = 0; + dest[s->i++] = ECRYPTFS_TAG_70_PACKET_TYPE; + rc = ecryptfs_write_packet_length(&dest[s->i], + (ECRYPTFS_SIG_SIZE + + 1 /* Cipher code */ + + s->block_aligned_filename_size), + &s->packet_size_len); + if (rc) { + printk(KERN_ERR "%s: Error generating tag 70 packet " + "header; cannot generate packet length; rc = [%d]\n", + __func__, rc); + goto out_free_unlock; + } + s->i += s->packet_size_len; + ecryptfs_from_hex(&dest[s->i], + mount_crypt_stat->global_default_fnek_sig, + ECRYPTFS_SIG_SIZE); + s->i += ECRYPTFS_SIG_SIZE; + s->cipher_code = ecryptfs_code_for_cipher_string( + mount_crypt_stat->global_default_fn_cipher_name, + mount_crypt_stat->global_default_fn_cipher_key_bytes); + if (s->cipher_code == 0) { + printk(KERN_WARNING "%s: Unable to generate code for " + "cipher [%s] with key bytes [%d]\n", __func__, + mount_crypt_stat->global_default_fn_cipher_name, + mount_crypt_stat->global_default_fn_cipher_key_bytes); + rc = -EINVAL; + goto out_free_unlock; + } + dest[s->i++] = s->cipher_code; + rc = ecryptfs_find_auth_tok_for_sig( + &s->auth_tok, mount_crypt_stat, + mount_crypt_stat->global_default_fnek_sig); + if (rc) { + printk(KERN_ERR "%s: Error attempting to find auth tok for " + "fnek sig [%s]; rc = [%d]\n", __func__, + mount_crypt_stat->global_default_fnek_sig, rc); + goto out_free_unlock; + } + /* TODO: Support other key modules than passphrase for + * filename encryption */ + BUG_ON(s->auth_tok->token_type != ECRYPTFS_PASSWORD); + sg_init_one( + &s->hash_sg, + (u8 *)s->auth_tok->token.password.session_key_encryption_key, + s->auth_tok->token.password.session_key_encryption_key_bytes); + s->hash_desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; + s->hash_desc.tfm = crypto_alloc_hash(ECRYPTFS_TAG_70_DIGEST, 0, + CRYPTO_ALG_ASYNC); + if (IS_ERR(s->hash_desc.tfm)) { + rc = PTR_ERR(s->hash_desc.tfm); + printk(KERN_ERR "%s: Error attempting to " + "allocate hash crypto context; rc = [%d]\n", + __func__, rc); + goto out_free_unlock; + } + rc = crypto_hash_init(&s->hash_desc); + if (rc) { + printk(KERN_ERR + "%s: Error initializing crypto hash; rc = [%d]\n", + __func__, rc); + goto out_release_free_unlock; + } + rc = crypto_hash_update( + &s->hash_desc, &s->hash_sg, + s->auth_tok->token.password.session_key_encryption_key_bytes); + if (rc) { + printk(KERN_ERR + "%s: Error updating crypto hash; rc = [%d]\n", + __func__, rc); + goto out_release_free_unlock; + } + rc = crypto_hash_final(&s->hash_desc, s->hash); + if (rc) { + printk(KERN_ERR + "%s: Error finalizing crypto hash; rc = [%d]\n", + __func__, rc); + goto out_release_free_unlock; + } + for (s->j = 0; s->j < (s->num_rand_bytes - 1); s->j++) { + s->block_aligned_filename[s->j] = + s->hash[(s->j % ECRYPTFS_TAG_70_DIGEST_SIZE)]; + if ((s->j % ECRYPTFS_TAG_70_DIGEST_SIZE) + == (ECRYPTFS_TAG_70_DIGEST_SIZE - 1)) { + sg_init_one(&s->hash_sg, (u8 *)s->hash, + ECRYPTFS_TAG_70_DIGEST_SIZE); + rc = crypto_hash_init(&s->hash_desc); + if (rc) { + printk(KERN_ERR + "%s: Error initializing crypto hash; " + "rc = [%d]\n", __func__, rc); + goto out_release_free_unlock; + } + rc = crypto_hash_update(&s->hash_desc, &s->hash_sg, + ECRYPTFS_TAG_70_DIGEST_SIZE); + if (rc) { + printk(KERN_ERR + "%s: Error updating crypto hash; " + "rc = [%d]\n", __func__, rc); + goto out_release_free_unlock; + } + rc = crypto_hash_final(&s->hash_desc, s->tmp_hash); + if (rc) { + printk(KERN_ERR + "%s: Error finalizing crypto hash; " + "rc = [%d]\n", __func__, rc); + goto out_release_free_unlock; + } + memcpy(s->hash, s->tmp_hash, + ECRYPTFS_TAG_70_DIGEST_SIZE); + } + if (s->block_aligned_filename[s->j] == '\0') + s->block_aligned_filename[s->j] = ECRYPTFS_NON_NULL; + } + memcpy(&s->block_aligned_filename[s->num_rand_bytes], filename, + filename_size); + rc = virt_to_scatterlist(s->block_aligned_filename, + s->block_aligned_filename_size, &s->src_sg, 1); + if (rc != 1) { + printk(KERN_ERR "%s: Internal error whilst attempting to " + "convert filename memory to scatterlist; " + "expected rc = 1; got rc = [%d]. " + "block_aligned_filename_size = [%d]\n", __func__, rc, + s->block_aligned_filename_size); + goto out_release_free_unlock; + } + rc = virt_to_scatterlist(&dest[s->i], s->block_aligned_filename_size, + &s->dst_sg, 1); + if (rc != 1) { + printk(KERN_ERR "%s: Internal error whilst attempting to " + "convert encrypted filename memory to scatterlist; " + "expected rc = 1; got rc = [%d]. " + "block_aligned_filename_size = [%d]\n", __func__, rc, + s->block_aligned_filename_size); + goto out_release_free_unlock; + } + /* The characters in the first block effectively do the job + * of the IV here, so we just use 0's for the IV. Note the + * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + * >= ECRYPTFS_MAX_IV_BYTES. */ + memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES); + s->desc.info = s->iv; + rc = crypto_blkcipher_setkey( + s->desc.tfm, + s->auth_tok->token.password.session_key_encryption_key, + mount_crypt_stat->global_default_fn_cipher_key_bytes); + if (rc < 0) { + printk(KERN_ERR "%s: Error setting key for crypto context; " + "rc = [%d]. s->auth_tok->token.password.session_key_" + "encryption_key = [0x%p]; mount_crypt_stat->" + "global_default_fn_cipher_key_bytes = [%Zd]\n", __func__, + rc, + s->auth_tok->token.password.session_key_encryption_key, + mount_crypt_stat->global_default_fn_cipher_key_bytes); + goto out_release_free_unlock; + } + rc = crypto_blkcipher_encrypt_iv(&s->desc, &s->dst_sg, &s->src_sg, + s->block_aligned_filename_size); + if (rc) { + printk(KERN_ERR "%s: Error attempting to encrypt filename; " + "rc = [%d]\n", __func__, rc); + goto out_release_free_unlock; + } + s->i += s->block_aligned_filename_size; + (*packet_size) = s->i; + (*remaining_bytes) -= (*packet_size); +out_release_free_unlock: + crypto_free_hash(s->hash_desc.tfm); +out_free_unlock: + memset(s->block_aligned_filename, 0, s->block_aligned_filename_size); + kfree(s->block_aligned_filename); +out_unlock: + mutex_unlock(s->tfm_mutex); +out: + kfree(s); + return rc; +} + +struct ecryptfs_parse_tag_70_packet_silly_stack { + u8 cipher_code; + size_t max_packet_size; + size_t packet_size_len; + size_t parsed_tag_70_packet_size; + size_t block_aligned_filename_size; + size_t block_size; + size_t i; + struct mutex *tfm_mutex; + char *decrypted_filename; + struct ecryptfs_auth_tok *auth_tok; + struct scatterlist src_sg; + struct scatterlist dst_sg; + struct blkcipher_desc desc; + char fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX + 1]; + char iv[ECRYPTFS_MAX_IV_BYTES]; + char cipher_string[ECRYPTFS_MAX_CIPHER_NAME_SIZE]; +}; + +/** + * parse_tag_70_packet - Parse and process FNEK-encrypted passphrase packet + * @filename: This function kmalloc's the memory for the filename + */ +int +ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size, + size_t *packet_size, + struct ecryptfs_mount_crypt_stat *mount_crypt_stat, + char *data, size_t max_packet_size) +{ + struct ecryptfs_parse_tag_70_packet_silly_stack *s; + int rc = 0; + + (*packet_size) = 0; + (*filename_size) = 0; + (*filename) = NULL; + s = kmalloc(sizeof(*s), GFP_KERNEL); + if (!s) { + printk(KERN_ERR "%s: Out of memory whilst trying to kmalloc " + "[%d] bytes of kernel memory\n", __func__, sizeof(*s)); + goto out; + } + s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; + if (max_packet_size < (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)) { + printk(KERN_WARNING "%s: max_packet_size is [%Zd]; it must be " + "at least [%d]\n", __func__, max_packet_size, + (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)); + rc = -EINVAL; + goto out; + } + /* Octet 0: Tag 70 identifier + * Octets 1-N1: Tag 70 packet size (includes cipher identifier + * and block-aligned encrypted filename size) + * Octets N1-N2: FNEK sig (ECRYPTFS_SIG_SIZE) + * Octet N2-N3: Cipher identifier (1 octet) + * Octets N3-N4: Block-aligned encrypted filename + * - Consists of a minimum number of random numbers, a \0 + * separator, and then the filename */ + if (data[(*packet_size)++] != ECRYPTFS_TAG_70_PACKET_TYPE) { + printk(KERN_WARNING "%s: Invalid packet tag [0x%.2x]; must be " + "tag [0x%.2x]\n", __func__, + data[((*packet_size) - 1)], ECRYPTFS_TAG_70_PACKET_TYPE); + rc = -EINVAL; + goto out; + } + rc = ecryptfs_parse_packet_length(&data[(*packet_size)], + &s->parsed_tag_70_packet_size, + &s->packet_size_len); + if (rc) { + printk(KERN_WARNING "%s: Error parsing packet length; " + "rc = [%d]\n", __func__, rc); + goto out; + } + s->block_aligned_filename_size = (s->parsed_tag_70_packet_size + - ECRYPTFS_SIG_SIZE - 1); + if ((1 + s->packet_size_len + s->parsed_tag_70_packet_size) + > max_packet_size) { + printk(KERN_WARNING "%s: max_packet_size is [%d]; real packet " + "size is [%d]\n", __func__, max_packet_size, + (1 + s->packet_size_len + 1 + + s->block_aligned_filename_size)); + rc = -EINVAL; + goto out; + } + (*packet_size) += s->packet_size_len; + ecryptfs_to_hex(s->fnek_sig_hex, &data[(*packet_size)], + ECRYPTFS_SIG_SIZE); + s->fnek_sig_hex[ECRYPTFS_SIG_SIZE_HEX] = '\0'; + (*packet_size) += ECRYPTFS_SIG_SIZE; + s->cipher_code = data[(*packet_size)++]; + rc = ecryptfs_cipher_code_to_string(s->cipher_string, s->cipher_code); + if (rc) { + printk(KERN_WARNING "%s: Cipher code [%d] is invalid\n", + __func__, s->cipher_code); + goto out; + } + rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&s->desc.tfm, + &s->tfm_mutex, + s->cipher_string); + if (unlikely(rc)) { + printk(KERN_ERR "Internal error whilst attempting to get " + "tfm and mutex for cipher name [%s]; rc = [%d]\n", + s->cipher_string, rc); + goto out; + } + mutex_lock(s->tfm_mutex); + rc = virt_to_scatterlist(&data[(*packet_size)], + s->block_aligned_filename_size, &s->src_sg, 1); + if (rc != 1) { + printk(KERN_ERR "%s: Internal error whilst attempting to " + "convert encrypted filename memory to scatterlist; " + "expected rc = 1; got rc = [%d]. " + "block_aligned_filename_size = [%d]\n", __func__, rc, + s->block_aligned_filename_size); + goto out_unlock; + } + (*packet_size) += s->block_aligned_filename_size; + s->decrypted_filename = kmalloc(s->block_aligned_filename_size, + GFP_KERNEL); + if (!s->decrypted_filename) { + printk(KERN_ERR "%s: Out of memory whilst attempting to " + "kmalloc [%d] bytes\n", __func__, + s->block_aligned_filename_size); + rc = -ENOMEM; + goto out_unlock; + } + rc = virt_to_scatterlist(s->decrypted_filename, + s->block_aligned_filename_size, &s->dst_sg, 1); + if (rc != 1) { + printk(KERN_ERR "%s: Internal error whilst attempting to " + "convert decrypted filename memory to scatterlist; " + "expected rc = 1; got rc = [%d]. " + "block_aligned_filename_size = [%d]\n", __func__, rc, + s->block_aligned_filename_size); + goto out_free_unlock; + } + /* The characters in the first block effectively do the job of + * the IV here, so we just use 0's for the IV. Note the + * constraint that ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES + * >= ECRYPTFS_MAX_IV_BYTES. */ + memset(s->iv, 0, ECRYPTFS_MAX_IV_BYTES); + s->desc.info = s->iv; + rc = ecryptfs_find_auth_tok_for_sig(&s->auth_tok, mount_crypt_stat, + s->fnek_sig_hex); + if (rc) { + printk(KERN_ERR "%s: Error attempting to find auth tok for " + "fnek sig [%s]; rc = [%d]\n", __func__, s->fnek_sig_hex, + rc); + goto out_free_unlock; + } + /* TODO: Support other key modules than passphrase for + * filename encryption */ + BUG_ON(s->auth_tok->token_type != ECRYPTFS_PASSWORD); + rc = crypto_blkcipher_setkey( + s->desc.tfm, + s->auth_tok->token.password.session_key_encryption_key, + mount_crypt_stat->global_default_fn_cipher_key_bytes); + if (rc < 0) { + printk(KERN_ERR "%s: Error setting key for crypto context; " + "rc = [%d]. s->auth_tok->token.password.session_key_" + "encryption_key = [0x%p]; mount_crypt_stat->" + "global_default_fn_cipher_key_bytes = [%Zd]\n", __func__, + rc, + s->auth_tok->token.password.session_key_encryption_key, + mount_crypt_stat->global_default_fn_cipher_key_bytes); + goto out_free_unlock; + } + rc = crypto_blkcipher_decrypt_iv(&s->desc, &s->dst_sg, &s->src_sg, + s->block_aligned_filename_size); + if (rc) { + printk(KERN_ERR "%s: Error attempting to decrypt filename; " + "rc = [%d]\n", __func__, rc); + goto out_free_unlock; + } + s->i = 0; + while (s->decrypted_filename[s->i] != '\0' + && s->i < s->block_aligned_filename_size) + s->i++; + if (s->i == s->block_aligned_filename_size) { + printk(KERN_WARNING "%s: Invalid tag 70 packet; could not " + "find valid separator between random characters and " + "the filename\n", __func__); + rc = -EINVAL; + goto out_free_unlock; + } + s->i++; + (*filename_size) = (s->block_aligned_filename_size - s->i); + if (!((*filename_size) > 0 && (*filename_size < PATH_MAX))) { + printk(KERN_WARNING "%s: Filename size is [%Zd], which is " + "invalid\n", __func__, (*filename_size)); + rc = -EINVAL; + goto out_free_unlock; + } + (*filename) = kmalloc(((*filename_size) + 1), GFP_KERNEL); + if (!(*filename)) { + printk(KERN_ERR "%s: Out of memory whilst attempting to " + "kmalloc [%d] bytes\n", __func__, + ((*filename_size) + 1)); + rc = -ENOMEM; + goto out_free_unlock; + } + memcpy((*filename), &s->decrypted_filename[s->i], (*filename_size)); + (*filename)[(*filename_size)] = '\0'; +out_free_unlock: + kfree(s->decrypted_filename); +out_unlock: + mutex_unlock(s->tfm_mutex); +out: + if (rc) { + (*packet_size) = 0; + (*filename_size) = 0; + (*filename) = NULL; + } + kfree(s); + return rc; +} + +static int ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok) { int rc = 0; @@ -897,30 +1460,6 @@ out: return rc; } -static int -ecryptfs_find_global_auth_tok_for_sig( - struct ecryptfs_global_auth_tok **global_auth_tok, - struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig) -{ - struct ecryptfs_global_auth_tok *walker; - int rc = 0; - - (*global_auth_tok) = NULL; - mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); - list_for_each_entry(walker, - &mount_crypt_stat->global_auth_tok_list, - mount_crypt_stat_list) { - if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX) == 0) { - (*global_auth_tok) = walker; - goto out; - } - } - rc = -EINVAL; -out: - mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); - return rc; -} - /** * ecryptfs_verify_version * @version: The version number to confirm @@ -990,43 +1529,6 @@ out: } /** - * ecryptfs_find_auth_tok_for_sig - * @auth_tok: Set to the matching auth_tok; NULL if not found - * @crypt_stat: inode crypt_stat crypto context - * @sig: Sig of auth_tok to find - * - * For now, this function simply looks at the registered auth_tok's - * linked off the mount_crypt_stat, so all the auth_toks that can be - * used must be registered at mount time. This function could - * potentially try a lot harder to find auth_tok's (e.g., by calling - * out to ecryptfsd to dynamically retrieve an auth_tok object) so - * that static registration of auth_tok's will no longer be necessary. - * - * Returns zero on no error; non-zero on error - */ -static int -ecryptfs_find_auth_tok_for_sig( - struct ecryptfs_auth_tok **auth_tok, - struct ecryptfs_crypt_stat *crypt_stat, char *sig) -{ - struct ecryptfs_mount_crypt_stat *mount_crypt_stat = - crypt_stat->mount_crypt_stat; - struct ecryptfs_global_auth_tok *global_auth_tok; - int rc = 0; - - (*auth_tok) = NULL; - if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok, - mount_crypt_stat, sig)) { - struct key *auth_tok_key; - - rc = ecryptfs_keyring_auth_tok_for_sig(&auth_tok_key, auth_tok, - sig); - } else - (*auth_tok) = global_auth_tok->global_auth_tok; - return rc; -} - -/** * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok. * @auth_tok: The passphrase authentication token to use to encrypt the FEK * @crypt_stat: The cryptographic context @@ -1256,7 +1758,8 @@ find_next_matching_auth_tok: rc = -EINVAL; goto out_wipe_list; } - ecryptfs_find_auth_tok_for_sig(&matching_auth_tok, crypt_stat, + ecryptfs_find_auth_tok_for_sig(&matching_auth_tok, + crypt_stat->mount_crypt_stat, candidate_auth_tok_sig); if (matching_auth_tok) { found_auth_tok = 1; @@ -1336,7 +1839,9 @@ pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok, int rc; rc = write_tag_66_packet(auth_tok->token.private_key.signature, - ecryptfs_code_for_cipher_string(crypt_stat), + ecryptfs_code_for_cipher_string( + crypt_stat->cipher, + crypt_stat->key_size), crypt_stat, &payload, &payload_len); if (rc) { ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n"); @@ -1696,7 +2201,8 @@ encrypted_session_key_set: dest[(*packet_size)++] = 0x04; /* version 4 */ /* TODO: Break from RFC2440 so that arbitrary ciphers can be * specified with strings */ - cipher_code = ecryptfs_code_for_cipher_string(crypt_stat); + cipher_code = ecryptfs_code_for_cipher_string(crypt_stat->cipher, + crypt_stat->key_size); if (cipher_code == 0) { ecryptfs_printk(KERN_WARNING, "Unable to generate code for " "cipher [%s]\n", crypt_stat->cipher); |