diff options
| -rw-r--r-- | fs/ecryptfs/crypto.c | 208 | ||||
| -rw-r--r-- | fs/ecryptfs/ecryptfs_kernel.h | 71 | ||||
| -rw-r--r-- | fs/ecryptfs/keystore.c | 743 | ||||
| -rw-r--r-- | fs/ecryptfs/main.c | 121 |
4 files changed, 742 insertions, 401 deletions
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index 6ac630625b70..4f7d89591970 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -204,6 +204,8 @@ void ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat) { memset((void *)crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat)); + INIT_LIST_HEAD(&crypt_stat->keysig_list); + mutex_init(&crypt_stat->keysig_list_mutex); mutex_init(&crypt_stat->cs_mutex); mutex_init(&crypt_stat->cs_tfm_mutex); mutex_init(&crypt_stat->cs_hash_tfm_mutex); @@ -218,20 +220,41 @@ ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat) */ void ecryptfs_destruct_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); 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)); } void ecryptfs_destruct_mount_crypt_stat( struct ecryptfs_mount_crypt_stat *mount_crypt_stat) { - if (mount_crypt_stat->global_auth_tok_key) - key_put(mount_crypt_stat->global_auth_tok_key); - if (mount_crypt_stat->global_key_tfm) - crypto_free_blkcipher(mount_crypt_stat->global_key_tfm); + struct ecryptfs_global_auth_tok *auth_tok, *auth_tok_tmp; + + if (!(mount_crypt_stat->flags & ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED)) + return; + mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); + list_for_each_entry_safe(auth_tok, auth_tok_tmp, + &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); + kmem_cache_free(ecryptfs_global_auth_tok_cache, auth_tok); + } + mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); memset(mount_crypt_stat, 0, sizeof(struct ecryptfs_mount_crypt_stat)); } @@ -931,6 +954,30 @@ static void ecryptfs_copy_mount_wide_flags_to_inode_flags( crypt_stat->flags |= ECRYPTFS_VIEW_AS_ENCRYPTED; } +static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs( + struct ecryptfs_crypt_stat *crypt_stat, + struct ecryptfs_mount_crypt_stat *mount_crypt_stat) +{ + struct ecryptfs_global_auth_tok *global_auth_tok; + int rc = 0; + + 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) { + 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: + return rc; +} + /** * ecryptfs_set_default_crypt_stat_vals * @crypt_stat @@ -973,46 +1020,44 @@ static void ecryptfs_set_default_crypt_stat_vals( /* Associate an authentication token(s) with the file */ int ecryptfs_new_file_context(struct dentry *ecryptfs_dentry) { - int rc = 0; struct ecryptfs_crypt_stat *crypt_stat = &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; struct ecryptfs_mount_crypt_stat *mount_crypt_stat = &ecryptfs_superblock_to_private( ecryptfs_dentry->d_sb)->mount_crypt_stat; int cipher_name_len; + int rc = 0; ecryptfs_set_default_crypt_stat_vals(crypt_stat, mount_crypt_stat); - /* See if there are mount crypt options */ - if (mount_crypt_stat->global_auth_tok) { - ecryptfs_printk(KERN_DEBUG, "Initializing context for new " - "file using mount_crypt_stat\n"); - crypt_stat->flags |= ECRYPTFS_ENCRYPTED; - crypt_stat->flags |= ECRYPTFS_KEY_VALID; - ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, - mount_crypt_stat); - memcpy(crypt_stat->keysigs[crypt_stat->num_keysigs++], - mount_crypt_stat->global_auth_tok_sig, - ECRYPTFS_SIG_SIZE_HEX); - cipher_name_len = - strlen(mount_crypt_stat->global_default_cipher_name); - memcpy(crypt_stat->cipher, - mount_crypt_stat->global_default_cipher_name, - cipher_name_len); - crypt_stat->cipher[cipher_name_len] = '\0'; - crypt_stat->key_size = - mount_crypt_stat->global_default_cipher_key_size; - ecryptfs_generate_new_key(crypt_stat); - } else - /* We should not encounter this scenario since we - * should detect lack of global_auth_tok at mount time - * TODO: Applies to 0.1 release only; remove in future - * release */ - BUG(); + mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); + BUG_ON(mount_crypt_stat->num_global_auth_toks == 0); + mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); + crypt_stat->flags |= ECRYPTFS_ENCRYPTED; + crypt_stat->flags |= ECRYPTFS_KEY_VALID; + ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat, + mount_crypt_stat); + rc = ecryptfs_copy_mount_wide_sigs_to_inode_sigs(crypt_stat, + mount_crypt_stat); + if (rc) { + printk(KERN_ERR "Error attempting to copy mount-wide key sigs " + "to the inode key sigs; rc = [%d]\n", rc); + goto out; + } + cipher_name_len = + strlen(mount_crypt_stat->global_default_cipher_name); + memcpy(crypt_stat->cipher, + mount_crypt_stat->global_default_cipher_name, + cipher_name_len); + crypt_stat->cipher[cipher_name_len] = '\0'; + crypt_stat->key_size = + mount_crypt_stat->global_default_cipher_key_size; + ecryptfs_generate_new_key(crypt_stat); rc = ecryptfs_init_crypt_ctx(crypt_stat); if (rc) ecryptfs_printk(KERN_ERR, "Error initializing cryptographic " "context for cipher [%s]: rc = [%d]\n", crypt_stat->cipher, rc); +out: return rc; } @@ -1776,7 +1821,7 @@ out: } /** - * ecryptfs_process_cipher - Perform cipher initialization. + * ecryptfs_process_key_cipher - Perform key cipher initialization. * @key_tfm: Crypto context for key material, set by this function * @cipher_name: Name of the cipher * @key_size: Size of the key in bytes @@ -1786,8 +1831,8 @@ out: * event, regardless of whether this function succeeds for fails. */ int -ecryptfs_process_cipher(struct crypto_blkcipher **key_tfm, char *cipher_name, - size_t *key_size) +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; @@ -1829,3 +1874,98 @@ ecryptfs_process_cipher(struct crypto_blkcipher **key_tfm, char *cipher_name, out: return rc; } + +struct kmem_cache *ecryptfs_key_tfm_cache; +struct list_head key_tfm_list; +struct mutex key_tfm_list_mutex; + +int ecryptfs_init_crypto(void) +{ + mutex_init(&key_tfm_list_mutex); + INIT_LIST_HEAD(&key_tfm_list); + return 0; +} + +int ecryptfs_destruct_crypto(void) +{ + struct ecryptfs_key_tfm *key_tfm, *key_tfm_tmp; + + mutex_lock(&key_tfm_list_mutex); + list_for_each_entry_safe(key_tfm, key_tfm_tmp, &key_tfm_list, + key_tfm_list) { + list_del(&key_tfm->key_tfm_list); + if (key_tfm->key_tfm) + crypto_free_blkcipher(key_tfm->key_tfm); + kmem_cache_free(ecryptfs_key_tfm_cache, key_tfm); + } + mutex_unlock(&key_tfm_list_mutex); + return 0; +} + +int +ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name, + size_t key_size) +{ + struct ecryptfs_key_tfm *tmp_tfm; + int rc = 0; + + tmp_tfm = kmem_cache_alloc(ecryptfs_key_tfm_cache, GFP_KERNEL); + if (key_tfm != NULL) + (*key_tfm) = tmp_tfm; + if (!tmp_tfm) { + rc = -ENOMEM; + printk(KERN_ERR "Error attempting to allocate from " + "ecryptfs_key_tfm_cache\n"); + goto out; + } + mutex_init(&tmp_tfm->key_tfm_mutex); + strncpy(tmp_tfm->cipher_name, cipher_name, + ECRYPTFS_MAX_CIPHER_NAME_SIZE); + tmp_tfm->key_size = key_size; + if ((rc = ecryptfs_process_key_cipher(&tmp_tfm->key_tfm, + tmp_tfm->cipher_name, + &tmp_tfm->key_size))) { + printk(KERN_ERR "Error attempting to initialize key TFM " + "cipher with name = [%s]; rc = [%d]\n", + tmp_tfm->cipher_name, rc); + kmem_cache_free(ecryptfs_key_tfm_cache, tmp_tfm); + if (key_tfm != NULL) + (*key_tfm) = NULL; + goto out; + } + mutex_lock(&key_tfm_list_mutex); + list_add(&tmp_tfm->key_tfm_list, &key_tfm_list); + mutex_unlock(&key_tfm_list_mutex); +out: + return rc; +} + +int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm, + struct mutex **tfm_mutex, + char *cipher_name) +{ + struct ecryptfs_key_tfm *key_tfm; + int rc = 0; + + (*tfm) = NULL; + (*tfm_mutex) = NULL; + mutex_lock(&key_tfm_list_mutex); + list_for_each_entry(key_tfm, &key_tfm_list, key_tfm_list) { + if (strcmp(key_tfm->cipher_name, cipher_name) == 0) { + (*tfm) = key_tfm->key_tfm; + (*tfm_mutex) = &key_tfm->key_tfm_mutex; + mutex_unlock(&key_tfm_list_mutex); + goto out; + } + } + mutex_unlock(&key_tfm_list_mutex); + if ((rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0))) { + printk(KERN_ERR "Error adding new key_tfm to list; rc = [%d]\n", + rc); + goto out; + } + (*tfm) = key_tfm->key_tfm; + (*tfm_mutex) = &key_tfm->key_tfm_mutex; +out: + return rc; +} diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index 1b9dd9a96f19..6ddab6c856ac 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -48,10 +48,12 @@ #define ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH 0x00000004 #define ECRYPTFS_VERSIONING_POLICY 0x00000008 #define ECRYPTFS_VERSIONING_XATTR 0x00000010 +#define ECRYPTFS_VERSIONING_MULTKEY 0x00000020 #define ECRYPTFS_VERSIONING_MASK (ECRYPTFS_VERSIONING_PASSPHRASE \ | ECRYPTFS_VERSIONING_PLAINTEXT_PASSTHROUGH \ | ECRYPTFS_VERSIONING_PUBKEY \ - | ECRYPTFS_VERSIONING_XATTR) + | ECRYPTFS_VERSIONING_XATTR \ + | ECRYPTFS_VERSIONING_MULTKEY) #define ECRYPTFS_MAX_PASSWORD_LENGTH 64 #define ECRYPTFS_MAX_PASSPHRASE_BYTES ECRYPTFS_MAX_PASSWORD_LENGTH #define ECRYPTFS_SALT_SIZE 8 @@ -144,6 +146,7 @@ struct ecryptfs_private_key { struct ecryptfs_auth_tok { u16 version; /* 8-bit major and 8-bit minor */ u16 token_type; +#define ECRYPTFS_ENCRYPT_ONLY 0x00000001 u32 flags; struct ecryptfs_session_key session_key; u8 reserved[32]; @@ -153,6 +156,7 @@ struct ecryptfs_auth_tok { } token; } __attribute__ ((packed)); +int ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok); void ecryptfs_dump_auth_tok(struct ecryptfs_auth_tok *auth_tok); extern void ecryptfs_to_hex(char *dst, char *src, size_t src_size); extern void ecryptfs_from_hex(char *dst, char *src, int dst_size); @@ -194,7 +198,6 @@ ecryptfs_get_key_payload_data(struct key *key) #define ECRYPTFS_MAX_KEYSET_SIZE 1024 #define ECRYPTFS_MAX_CIPHER_NAME_SIZE 32 #define ECRYPTFS_MAX_NUM_ENC_KEYS 64 -#define ECRYPTFS_MAX_NUM_KEYSIGS 2 /* TODO: Make this a linked list */ #define ECRYPTFS_MAX_IV_BYTES 16 /* 128 bits */ #define ECRYPTFS_SALT_BYTES 2 #define MAGIC_ECRYPTFS_MARKER 0x3c81b7f5 @@ -212,6 +215,11 @@ ecryptfs_get_key_payload_data(struct key *key) #define ECRYPTFS_TAG_67_PACKET_TYPE 0x43 #define MD5_DIGEST_SIZE 16 +struct ecryptfs_key_sig { + struct list_head crypt_stat_list; + char keysig[ECRYPTFS_SIG_SIZE_HEX]; +}; + /** * This is the primary struct associated with each encrypted file. * @@ -231,7 +239,6 @@ struct ecryptfs_crypt_stat { u32 flags; unsigned int file_version; size_t iv_bytes; - size_t num_keysigs; size_t header_extent_size; size_t num_header_extents_at_front; size_t extent_size; /* Data extent size; default is 4096 */ @@ -245,7 +252,8 @@ struct ecryptfs_crypt_stat { unsigned char cipher[ECRYPTFS_MAX_CIPHER_NAME_SIZE]; unsigned char key[ECRYPTFS_MAX_KEY_BYTES]; unsigned char root_iv[ECRYPTFS_MAX_IV_BYTES]; - unsigned char keysigs[ECRYPTFS_MAX_NUM_KEYSIGS][ECRYPTFS_SIG_SIZE_HEX]; + struct list_head keysig_list; + struct mutex keysig_list_mutex; struct mutex cs_tfm_mutex; struct mutex cs_hash_tfm_mutex; struct mutex cs_mutex; @@ -265,6 +273,26 @@ struct ecryptfs_dentry_info { struct ecryptfs_crypt_stat *crypt_stat; }; +struct ecryptfs_global_auth_tok { +#define ECRYPTFS_AUTH_TOK_INVALID 0x00000001 + u32 flags; + struct list_head mount_crypt_stat_list; + struct key *global_auth_tok_key; + struct ecryptfs_auth_tok *global_auth_tok; + unsigned char sig[ECRYPTFS_SIG_SIZE_HEX + 1]; +}; + +struct ecryptfs_key_tfm { + struct crypto_blkcipher *key_tfm; + size_t key_size; + struct mutex key_tfm_mutex; + struct list_head key_tfm_list; + unsigned char cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1]; +}; + +extern struct list_head key_tfm_list; +extern struct mutex key_tfm_list_mutex; + /** * This struct is to enable a mount-wide passphrase/salt combo. This * is more or less a stopgap to provide similar functionality to other @@ -276,15 +304,14 @@ struct ecryptfs_mount_crypt_stat { #define ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED 0x00000001 #define ECRYPTFS_XATTR_METADATA_ENABLED 0x00000002 #define ECRYPTFS_ENCRYPTED_VIEW_ENABLED 0x00000004 +#define ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED 0x00000008 u32 flags; - struct ecryptfs_auth_tok *global_auth_tok; - struct key *global_auth_tok_key; + 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; - struct crypto_blkcipher *global_key_tfm; - struct mutex global_key_tfm_mutex; unsigned char global_default_cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1]; - unsigned char global_auth_tok_sig[ECRYPTFS_SIG_SIZE_HEX + 1]; }; /* superblock private data. */ @@ -468,6 +495,9 @@ extern struct kmem_cache *ecryptfs_header_cache_2; extern struct kmem_cache *ecryptfs_xattr_cache; extern struct kmem_cache *ecryptfs_lower_page_cache; extern struct kmem_cache *ecryptfs_key_record_cache; +extern struct kmem_cache *ecryptfs_key_sig_cache; +extern struct kmem_cache *ecryptfs_global_auth_tok_cache; +extern struct kmem_cache *ecryptfs_key_tfm_cache; int ecryptfs_interpose(struct dentry *hidden_dentry, struct dentry *this_dentry, struct super_block *sb, @@ -538,9 +568,8 @@ int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat, unsigned char *src, struct dentry *ecryptfs_dentry); int ecryptfs_truncate(struct dentry *dentry, loff_t new_length); -int -ecryptfs_process_cipher(struct crypto_blkcipher **key_tfm, char *cipher_name, - size_t *key_size); +int ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm, + char *cipher_name, size_t *key_size); int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode); int ecryptfs_inode_set(struct inode *inode, void *lower_inode); void ecryptfs_init_inode(struct inode *inode, struct inode *lower_inode); @@ -580,6 +609,24 @@ void ecryptfs_write_header_metadata(char *virt, struct ecryptfs_crypt_stat *crypt_stat, size_t *written); +int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig); +int +ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, + char *sig); +int ecryptfs_get_global_auth_tok_for_sig( + struct ecryptfs_global_auth_tok **global_auth_tok, + struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig); +int +ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name, + size_t key_size); +int ecryptfs_init_crypto(void); +int ecryptfs_destruct_crypto(void); +int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm, + struct mutex **tfm_mutex, + char *cipher_name); +int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key, + struct ecryptfs_auth_tok **auth_tok, + char *sig); int ecryptfs_write_zeros(struct file *file, pgoff_t index, int start, int num_zeros); diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c index b550dea8eee6..a1764fe3318c 100644 --- a/fs/ecryptfs/keystore.c +++ b/fs/ecryptfs/keystore.c @@ -402,20 +402,24 @@ out: * * Returns Zero on success; non-zero error otherwise. */ -static int decrypt_pki_encrypted_session_key( - struct ecryptfs_mount_crypt_stat *mount_crypt_stat, - struct ecryptfs_auth_tok *auth_tok, - struct ecryptfs_crypt_stat *crypt_stat) +static int +decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, + struct ecryptfs_crypt_stat *crypt_stat) { u16 cipher_code = 0; struct ecryptfs_msg_ctx *msg_ctx; struct ecryptfs_message *msg = NULL; + char *auth_tok_sig; char *netlink_message; size_t netlink_message_length; int rc; - rc = write_tag_64_packet(mount_crypt_stat->global_auth_tok_sig, - &(auth_tok->session_key), + if ((rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok))) { + printk(KERN_ERR "Unrecognized auth tok type: [%d]\n", + auth_tok->token_type); + goto out; + } + rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key), &netlink_message, &netlink_message_length); if (rc) { ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet"); @@ -921,126 +925,241 @@ 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; +} + /** - * decrypt_session_key - Decrypt the session key with the given auth_tok. + * ecryptfs_verify_version + * @version: The version number to confirm + * + * Returns zero on good version; non-zero otherwise + */ +static int ecryptfs_verify_version(u16 version) +{ + int rc = 0; + unsigned char major; + unsigned char minor; + + major = ((version >> 8) & 0xFF); + minor = (version & 0xFF); + if (major != ECRYPTFS_VERSION_MAJOR) { + ecryptfs_printk(KERN_ERR, "Major version number mismatch. " + "Expected [%d]; got [%d]\n", + ECRYPTFS_VERSION_MAJOR, major); + rc = -EINVAL; + goto out; + } + if (minor != ECRYPTFS_VERSION_MINOR) { + ecryptfs_printk(KERN_ERR, "Minor version number mismatch. " + "Expected [%d]; got [%d]\n", + ECRYPTFS_VERSION_MINOR, minor); + rc = -EINVAL; + goto out; + } +out: + return rc; +} + +int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key, + struct ecryptfs_auth_tok **auth_tok, + char *sig) +{ + int rc = 0; + + (*auth_tok_key) = request_key(&key_type_user, sig, NULL); + if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) { + printk(KERN_ERR "Could not find key with description: [%s]\n", + sig); + process_request_key_err(PTR_ERR(*auth_tok_key)); + rc = -EINVAL; + goto out; + } + (*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key); + if (ecryptfs_verify_version((*auth_tok)->version)) { + printk(KERN_ERR + "Data structure version mismatch. " + "Userspace tools must match eCryptfs " + "kernel module with major version [%d] " + "and minor version [%d]\n", + ECRYPTFS_VERSION_MAJOR, + ECRYPTFS_VERSION_MINOR); + rc = -EINVAL; + goto out; + } + if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD + && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) { + printk(KERN_ERR "Invalid auth_tok structure " + "returned from key query\n"); + rc = -EINVAL; + goto out; + } +out: + 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_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. * * Returns Zero on success; non-zero error otherwise. */ -static int decrypt_session_key(struct ecryptfs_auth_tok *auth_tok, - struct ecryptfs_crypt_stat *crypt_stat) +static int +decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok, + struct ecryptfs_crypt_stat *crypt_stat) { - struct ecryptfs_password *password_s_ptr; - struct scatterlist src_sg[2], dst_sg[2]; + struct scatterlist dst_sg; + struct scatterlist src_sg; struct mutex *tfm_mutex = NULL; - char *encrypted_session_key; - char *session_key; struct blkcipher_desc desc = { .flags = CRYPTO_TFM_REQ_MAY_SLEEP }; int rc = 0; - password_s_ptr = &auth_tok->token.password; - if (password_s_ptr->flags & ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) - ecryptfs_printk(KERN_DEBUG, "Session key encryption key " - "set; skipping key generation\n"); - ecryptfs_printk(KERN_DEBUG, "Session key encryption key (size [%d])" - ":\n", - password_s_ptr->session_key_encryption_key_bytes); - if (ecryptfs_verbosity > 0) - ecryptfs_dump_hex(password_s_ptr->session_key_encryption_key, - password_s_ptr-> - session_key_encryption_key_bytes); - if (!strcmp(crypt_stat->cipher, - crypt_stat->mount_crypt_stat->global_default_cipher_name) - && crypt_stat->mount_crypt_stat->global_key_tfm) { - desc.tfm = crypt_stat->mount_crypt_stat->global_key_tfm; - tfm_mutex = &crypt_stat->mount_crypt_stat->global_key_tfm_mutex; - } else { - char *full_alg_name; - - rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, - crypt_stat->cipher, - "ecb"); - if (rc) - goto out; - desc.tfm = crypto_alloc_blkcipher(full_alg_name, 0, - CRYPTO_ALG_ASYNC); - kfree(full_alg_name); - if (IS_ERR(desc.tfm)) { - rc = PTR_ERR(desc.tfm); - printk(KERN_ERR "Error allocating crypto context; " - "rc = [%d]\n", rc); - goto out; - } - crypto_blkcipher_set_flags(desc.tfm, CRYPTO_TFM_REQ_WEAK_KEY); + if (unlikely(ecryptfs_verbosity > 0)) { + ecryptfs_printk( + KERN_DEBUG, "Session key encryption key (size [%d]):\n", + auth_tok->token.password.session_key_encryption_key_bytes); + ecryptfs_dump_hex( + auth_tok->token.password.session_key_encryption_key, + auth_tok->token.password.session_key_encryption_key_bytes); + } + rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex, + crypt_stat->cipher); + if (unlikely(rc)) { + printk(KERN_ERR "Internal error whilst attempting to get " + "tfm and mutex for cipher name [%s]; rc = [%d]\n", + crypt_stat->cipher, rc); + goto out; } - if (tfm_mutex) - mutex_lock(tfm_mutex); - rc = crypto_blkcipher_setkey(desc.tfm, - password_s_ptr->session_key_encryption_key, - crypt_stat->key_size); - if (rc < 0) { + if ((rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key, + auth_tok->session_key.encrypted_key_size, + &src_sg, 1)) != 1) { + printk(KERN_ERR "Internal error whilst attempting to convert " + "auth_tok->session_key.encrypted_key to scatterlist; " + "expected rc = 1; got rc = [%d]. " + "auth_tok->session_key.encrypted_key_size = [%d]\n", rc, + auth_tok->session_key.encrypted_key_size); + goto out; + } + auth_tok->session_key.decrypted_key_size = + auth_tok->session_key.encrypted_key_size; + if ((rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key, + auth_tok->session_key.decrypted_key_size, + &dst_sg, 1)) != 1) { + printk(KERN_ERR "Internal error whilst attempting to convert " + "auth_tok->session_key.decrypted_key to scatterlist; " + "expected rc = 1; got rc = [%d]\n", rc); + goto out; + } + mutex_lock(tfm_mutex); + rc = crypto_blkcipher_setkey( + desc.tfm, auth_tok->token.password.session_key_encryption_key, + crypt_stat->key_size); + if (unlikely(rc < 0)) { + mutex_unlock(tfm_mutex); printk(KERN_ERR "Error setting key for crypto context\n"); rc = -EINVAL; - goto out_free_tfm; - } - /* TODO: virt_to_scatterlist */ - encrypted_session_key = (char *)__get_free_page(GFP_KERNEL); - if (!encrypted_session_key) { - ecryptfs_printk(KERN_ERR, "Out of memory\n"); - rc = -ENOMEM; - goto out_free_tfm; + goto out; } - session_key = (char *)__get_free_page(GFP_KERNEL); - if (!session_key) { - kfree(encrypted_session_key); - ecryptfs_printk(KERN_ERR, "Out of memory\n"); - rc = -ENOMEM; - goto out_free_tfm; - } - memcpy(encrypted_session_key, auth_tok->session_key.encrypted_key, - auth_tok->session_key.encrypted_key_size); - src_sg[0].page = virt_to_page(encrypted_session_key); - src_sg[0].offset = 0; - BUG_ON(auth_tok->session_key.encrypted_key_size > PAGE_CACHE_SIZE); - src_sg[0].length = auth_tok->session_key.encrypted_key_size; - dst_sg[0].page = virt_to_page(session_key); - dst_sg[0].offset = 0; - auth_tok->session_key.decrypted_key_size = - auth_tok->session_key.encrypted_key_size; - dst_sg[0].length = auth_tok->session_key.encrypted_key_size; - rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg, + rc = crypto_blkcipher_decrypt(&desc, &dst_sg, &src_sg, auth_tok->session_key.encrypted_key_size); - if (rc) { + mutex_unlock(tfm_mutex); + if (unlikely(rc)) { printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc); - goto out_free_memory; + goto out; } - auth_tok->session_key.decrypted_key_size = - auth_tok->session_key.encrypted_key_size; - memcpy(auth_tok->session_key.decrypted_key, session_key, - auth_tok->session_key.decrypted_key_size); auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY; memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key, auth_tok->session_key.decrypted_key_size); crypt_stat->flags |= ECRYPTFS_KEY_VALID; - ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n"); - if (ecryptfs_verbosity > 0) + if (unlikely(ecryptfs_verbosity > 0)) { + ecryptfs_printk(KERN_DEBUG, "FEK of size [%d]:\n", + crypt_stat->key_size); ecryptfs_dump_hex(crypt_stat->key, crypt_stat->key_size); -out_free_memory: - memset(encrypted_session_key, 0, PAGE_CACHE_SIZE); - free_page((unsigned long)encrypted_session_key); - memset(session_key, 0, PAGE_CACHE_SIZE); - free_page((unsigned long)session_key); -out_free_tfm: - if (tfm_mutex) - mutex_unlock(tfm_mutex); - else - crypto_free_blkcipher(desc.tfm); + } out: return rc; } +int ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok) +{ + int rc = 0; + + (*sig) = NULL; + switch (auth_tok->token_type) { + case ECRYPTFS_PASSWORD: + (*sig) = auth_tok->token.password.signature; + break; + case ECRYPTFS_PRIVATE_KEY: + (*sig) = auth_tok->token.private_key.signature; + break; + default: + printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n", + auth_tok->token_type); + rc = -EINVAL; + } + return rc; +} + /** * ecryptfs_parse_packet_set * @dest: The header page in memory @@ -1058,25 +1177,22 @@ int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat, struct dentry *ecryptfs_dentry) { size_t i = 0; - size_t found_auth_tok = 0; + size_t found_auth_tok; size_t next_packet_is_auth_tok_packet; - char sig[ECRYPTFS_SIG_SIZE_HEX]; struct list_head auth_tok_list; - struct list_head *walker; - struct ecryptfs_auth_tok *chosen_auth_tok = NULL; - struct ecryptfs_mount_crypt_stat *mount_crypt_stat = - &ecryptfs_superblock_to_private( - ecryptfs_dentry->d_sb)->mount_crypt_stat; + struct ecryptfs_auth_tok *matching_auth_tok = NULL; struct ecryptfs_auth_tok *candidate_auth_tok = NULL; + char *candidate_auth_tok_sig; size_t packet_size; struct ecryptfs_auth_tok *new_auth_tok; unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE]; + struct ecryptfs_auth_tok_list_item *auth_tok_list_item; size_t tag_11_contents_size; size_t tag_11_packet_size; int rc = 0; INIT_LIST_HEAD(&auth_tok_list); - /* Parse the header to find as many packets as we can, these will be + /* Parse the header to find as many packets as we can; these will be * added the our &auth_tok_list */ next_packet_is_auth_tok_packet = 1; while (next_packet_is_auth_tok_packet) { @@ -1155,73 +1271,86 @@ int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat, } } if (list_empty(&auth_tok_list)) { - rc = -EINVAL; /* Do not support non-encrypted files in - * the 0.1 release */ + printk(KERN_ERR "The lower file appears to be a non-encrypted " + "eCryptfs file; this is not supported in this version " + "of the eCryptfs kernel module\n"); + rc = -EINVAL; goto out; } - /* If we have a global auth tok, then we should try to use - * it */ - if (mount_crypt_stat->global_auth_tok) { - memcpy(sig, mount_crypt_stat->global_auth_tok_sig, - ECRYPTFS_SIG_SIZE_HEX); - chosen_auth_tok = mount_crypt_stat->global_auth_tok; - } else - BUG(); /* We should always have a global auth tok in - * the 0.1 release */ - /* Scan list to see if our chosen_auth_tok works */ - list_for_each(walker, &auth_tok_list) { - struct ecryptfs_auth_tok_list_item *auth_tok_list_item; - auth_tok_list_item = - list_entry(walker, struct ecryptfs_auth_tok_list_item, - list); + /* auth_tok_list contains the set of authentication tokens + * parsed from the metadata. We need to find a matching + * authentication token that has the secret component(s) + * necessary to decrypt the EFEK in the auth_tok parsed from + * the metadata. There may be several potential matches, but + * just one will be sufficient to decrypt to get the FEK. */ +find_next_matching_auth_tok: + found_auth_tok = 0; + list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) { candidate_auth_tok = &auth_tok_list_item->auth_tok; if (unlikely(ecryptfs_verbosity > 0)) { ecryptfs_printk(KERN_DEBUG, "Considering cadidate auth tok:\n"); ecryptfs_dump_auth_tok(candidate_auth_tok); } - /* TODO: Replace ECRYPTFS_SIG_SIZE_HEX w/ dynamic value */ - if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD - && !strncmp(candidate_auth_tok->token.password.signature, - sig, ECRYPTFS_SIG_SIZE_HEX)) { - found_auth_tok = 1; - goto leave_list; - /* TODO: Transfer the common salt into the - * crypt_stat salt */ - } else if ((candidate_auth_tok->token_type - == ECRYPTFS_PRIVATE_KEY) - && !strncmp(candidate_auth_tok->token.private_key.signature, - sig, ECRYPTFS_SIG_SIZE_HEX)) { + if ((rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig, + candidate_auth_tok))) { + printk(KERN_ERR + "Unrecognized candidate auth tok type: [%d]\n", + candidate_auth_tok->token_type); + rc = -EINVAL; + goto out_wipe_list; + } + if ((rc = ecryptfs_find_auth_tok_for_sig( + &matching_auth_tok, crypt_stat, + candidate_auth_tok_sig))) + rc = 0; + if (matching_auth_tok) { found_auth_tok = 1; - goto leave_list; + goto found_matching_auth_tok; } } if (!found_auth_tok) { - ecryptfs_printk(KERN_ERR, "Could not find authentication " - "token on temporary list for sig [%.*s]\n", - ECRYPTFS_SIG_SIZE_HEX, sig); + ecryptfs_printk(KERN_ERR, "Could not find a usable " + "authentication token\n"); rc = -EIO; goto out_wipe_list; } -leave_list: - rc = -ENOTSUPP; +found_matching_auth_tok: if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { memcpy(&(candidate_auth_tok->token.private_key), - &(chosen_auth_tok->token.private_key), + &(matching_auth_tok->token.private_key), sizeof(struct ecryptfs_private_key)); - rc = decrypt_pki_encrypted_session_key(mount_crypt_stat, - candidate_auth_tok, + rc = decrypt_pki_encrypted_session_key(candidate_auth_tok, crypt_stat); } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) { memcpy(&(candidate_auth_tok->token.password), - &(chosen_auth_tok->token.password), + &(matching_auth_tok->token.password), sizeof(struct ecryptfs_password)); - rc = decrypt_session_key(candidate_auth_tok, crypt_stat); + rc = decrypt_passphrase_encrypted_session_key( + candidate_auth_tok, crypt_stat); } if (rc) { - ecryptfs_printk(KERN_ERR, "Error decrypting the " - "session key; rc = [%d]\n", rc); - goto out_wipe_list; + struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp; + + ecryptfs_printk(KERN_WARNING, "Error decrypting the " + "session key for authentication token with sig " + "[%.*s]; rc = [%d]. Removing auth tok " + "candidate from the list and searching for " + "the next match.\n", candidate_auth_tok_sig, + ECRYPTFS_SIG_SIZE_HEX, rc); + list_for_each_entry_safe(auth_tok_list_item, + auth_tok_list_item_tmp, + &auth_tok_list, list) { + if (candidate_auth_tok + == &auth_tok_list_item->auth_tok) { + list_del(&auth_tok_list_item->list); + kmem_cache_free( + ecryptfs_auth_tok_list_item_cache, + auth_tok_list_item); + goto find_next_matching_auth_tok; + } + } + BUG(); } rc = ecryptfs_compute_root_iv(crypt_stat); if (rc) { @@ -1240,6 +1369,7 @@ out_wipe_list: out: return rc; } + static int pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok, struct ecryptfs_crypt_stat *crypt_stat, @@ -1291,15 +1421,15 @@ out: * Returns zero on success; non-zero on error. */ static int -write_tag_1_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok, +write_tag_1_packet(char *dest, size_t *remaining_bytes, + struct ecryptfs_auth_tok *auth_tok, struct ecryptfs_crypt_stat *crypt_stat, - struct ecryptfs_mount_crypt_stat *mount_crypt_stat, struct ecryptfs_key_record *key_rec, size_t *packet_size) { size_t i; size_t encrypted_session_key_valid = 0; - size_t key_rec_size; size_t packet_size_length; + size_t max_packet_size; int rc = 0; (*packet_size) = 0; @@ -1329,37 +1459,23 @@ write_tag_1_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok, ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size); } encrypted_session_key_set: - /* Now we have a valid key_rec. Append it to the - * key_rec set. */ - key_rec_size = (sizeof(struct ecryptfs_key_record) - - ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES - + (key_rec->enc_key_size)); - /* TODO: Include a packet size limit as a parameter to this - * function once we have multi-packet headers (for versions - * later than 0.1 */ - if (key_rec_size >= ECRYPTFS_MAX_KEYSET_SIZE) { - ecryptfs_printk(KERN_ERR, "Keyset too large\n"); - rc = -EINVAL; - goto out; - } - /* ***** TAG 1 Packet Format ***** - * | version number | 1 byte | - * | key ID | 8 bytes | - * | public key algorithm | 1 byte | - * | encrypted session key | arbitrary | - */ - if ((0x02 + ECRYPTFS_SIG_SIZE + key_rec->enc_key_size) >= max) { - ecryptfs_printk(KERN_ERR, - "Authentication token is too large\n"); + /* This format is inspired by OpenPGP; see RFC 2440 + * packet tag 1 */ + max_packet_size = (1 /* Tag 1 identifier */ + + 3 /* Max Tag 1 packet size */ + + 1 /* Version */ + + ECRYPTFS_SIG_SIZE /* Key identifier */ + + 1 /* Cipher identifier */ + + key_rec->enc_key_size); /* Encrypted key size */ + if (max_packet_size > (*remaining_bytes)) { + printk(KERN_ERR "Packet length larger than maximum allowable; " + "need up to [%d] bytes, but there are only [%d] " + "available\n", max_packet_size, (*remaining_bytes)); rc = -EINVAL; goto out; } dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE; - /* This format is inspired by OpenPGP; see RFC 2440 - * packet tag 1 */ - rc = write_packet_length(&dest[(*packet_size)], - (0x02 + ECRYPTFS_SIG_SIZE + - key_rec->enc_key_size), + rc = write_packet_length(&dest[(*packet_size)], (max_packet_size - 4), &packet_size_length); if (rc) { ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet " @@ -1377,6 +1493,8 @@ encrypted_session_key_set: out: if (rc) (*packet_size) = 0; + else + (*remaining_bytes) -= (*packet_size); return rc; } @@ -1448,19 +1566,22 @@ write_tag_11_packet(char *dest, int max, char *contents, size_t contents_length, * Returns zero on success; non-zero on error. */ static int -write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok, +write_tag_3_packet(char *dest, size_t *remaining_bytes, + struct ecryptfs_auth_tok *auth_tok, struct ecryptfs_crypt_stat *crypt_stat, struct ecryptfs_key_record *key_rec, size_t *packet_size) { size_t i; size_t encrypted_session_key_valid = 0; char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES]; - struct scatterlist dest_sg[2]; - struct scatterlist src_sg[2]; + struct scatterlist dst_sg; + struct scatterlist src_sg; struct mutex *tfm_mutex = NULL; - size_t key_rec_size; - size_t packet_size_length; size_t cipher_code; + size_t packet_size_length; + size_t max_packet_size; + struct ecryptfs_mount_crypt_stat *mount_crypt_stat = + crypt_stat->mount_crypt_stat; struct blkcipher_desc desc = { .tfm = NULL, .flags = CRYPTO_TFM_REQ_MAY_SLEEP @@ -1470,16 +1591,25 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok, (*packet_size) = 0; ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature, ECRYPTFS_SIG_SIZE); - encrypted_session_key_valid = 0; - for (i = 0; i < crypt_stat->key_size; i++) - encrypted_session_key_valid |= - auth_tok->session_key.encrypted_key[i]; - if (encrypted_session_key_valid) { - memcpy(key_rec->enc_key, - auth_tok->session_key.encrypted_key, - auth_tok->session_key.encrypted_key_size); - goto encrypted_session_key_set; + rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex, + crypt_stat->cipher); + if (unlikely(rc)) { + printk(KERN_ERR "Internal error whilst attempting to get " + "tfm and mutex for cipher name [%s]; rc = [%d]\n", + crypt_stat->cipher, rc); + goto out; + } + if (mount_crypt_stat->global_default_cipher_key_size == 0) { + struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm); + + printk(KERN_WARNING "No key size specified at mount; " + "defaulting to [%d]\n", alg->max_keysize); + mount_crypt_stat->global_default_cipher_key_size = + alg->max_keysize; } + if (crypt_stat->key_size == 0) + crypt_stat->key_size = + mount_crypt_stat->global_default_cipher_key_size; if (auth_tok->session_key.encrypted_key_size == 0) auth_tok->session_key.encrypted_key_size = crypt_stat->key_size; @@ -1487,9 +1617,24 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok, && strcmp("aes", crypt_stat->cipher) == 0) { memset((crypt_stat->key + 24), 0, 8); auth_tok->session_key.encrypted_key_size = 32; - } + } else + auth_tok->session_key.encrypted_key_size = crypt_stat->key_size; key_rec->enc_key_size = auth_tok->session_key.encrypted_key_size; + encrypted_session_key_valid = 0; + for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++) + encrypted_session_key_valid |= + auth_tok->session_key.encrypted_key[i]; + if (encrypted_session_key_valid) { + ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; " + "using auth_tok->session_key.encrypted_key, " + "where key_rec->enc_key_size = [%d]\n", + key_rec->enc_key_size); + memcpy(key_rec->enc_key, + auth_tok->session_key.encrypted_key, + key_rec->enc_key_size); + goto encrypted_session_key_set; + } if (auth_tok->token.password.flags & ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) { ecryptfs_printk(KERN_DEBUG, "Using previously generated " @@ -1508,54 +1653,32 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok, ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n"); ecryptfs_dump_hex(session_key_encryption_key, 16); } - rc = virt_to_scatterlist(crypt_stat->key, - key_rec->enc_key_size, src_sg, 2); - if (!rc) { + if ((rc = virt_to_scatterlist(crypt_stat->key, + key_rec->enc_key_size, &src_sg, 1)) + != 1) { ecryptfs_printk(KERN_ERR, "Error generating scatterlist " - "for crypt_stat session key\n"); + "for crypt_stat session key; expected rc = 1; " + "got rc = [%d]. key_rec->enc_key_size = [%d]\n", + rc, key_rec->enc_key_size); rc = -ENOMEM; goto out; } - rc = virt_to_scatterlist(key_rec->enc_key, - key_rec->enc_key_size, dest_sg, 2); - if (!rc) { + if ((rc = virt_to_scatterlist(key_rec->enc_key, + key_rec->enc_key_size, &dst_sg, 1)) + != 1) { ecryptfs_printk(KERN_ERR, "Error generating scatterlist " - "for crypt_stat encrypted session key\n"); + "for crypt_stat encrypted session key; " + "expected rc = 1; got rc = [%d]. " + "key_rec->enc_key_size = [%d]\n", rc, + key_rec->enc_key_size); rc = -ENOMEM; goto out; } - if (!strcmp(crypt_stat->cipher, - crypt_stat->mount_crypt_stat->global_default_cipher_name) - && crypt_stat->mount_crypt_stat->global_key_tfm) { - desc.tfm = crypt_stat->mount_crypt_stat->global_key_tfm; - tfm_mutex = &crypt_stat->mount_crypt_stat->global_key_tfm_mutex; - } else { - char *full_alg_name; - - rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, - crypt_stat->cipher, - "ecb"); - if (rc) - goto out; - desc.tfm = crypto_alloc_blkcipher(full_alg_name, 0, - CRYPTO_ALG_ASYNC); - kfree(full_alg_name); - if (IS_ERR(desc.tfm)) { - rc = PTR_ERR(desc.tfm); - ecryptfs_printk(KERN_ERR, "Could not initialize crypto " - "context for cipher [%s]; rc = [%d]\n", - crypt_stat->cipher, rc); - goto out; - } - crypto_blkcipher_set_flags(desc.tfm, CRYPTO_TFM_REQ_WEAK_KEY); - } - if (tfm_mutex) - mutex_lock(tfm_mutex); + mutex_lock(tfm_mutex); rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key, crypt_stat->key_size); if (rc < 0) { - if (tfm_mutex) - mutex_unlock(tfm_mutex); + mutex_unlock(tfm_mutex); ecryptfs_printk(KERN_ERR, "Error setting key for crypto " "context; rc = [%d]\n", rc); goto out; @@ -1563,56 +1686,53 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok, rc = 0; ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n", crypt_stat->key_size); - rc = crypto_blkcipher_encrypt(&desc, dest_sg, src_sg, + rc = crypto_blkcipher_encrypt(&desc, &dst_sg, &src_sg, (*key_rec).enc_key_size); + mutex_unlock(tfm_mutex); if (rc) { printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc); goto out; } - if (tfm_mutex) - mutex_unlock(tfm_mutex); ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n"); - if (ecryptfs_verbosity > 0) + if (ecryptfs_verbosity > 0) { + ecryptfs_printk(KERN_DEBUG, "EFEK of size [%d]:\n", + key_rec->enc_key_size); ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size); -encrypted_session_key_set: - /* Now we have a valid key_rec. Append it to the - * key_rec set. */ - key_rec_size = (sizeof(struct ecryptfs_key_record) - - ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES - + (key_rec->enc_key_size)); - /* TODO: Include a packet size limit as a parameter to this - * function once we have multi-packet headers (for versions - * later than 0.1 */ - if (key_rec_size >= ECRYPTFS_MAX_KEYSET_SIZE) { - ecryptfs_printk(KERN_ERR, "Keyset too large\n"); - rc = -EINVAL; - goto out; } - /* TODO: Packet size limit */ - /* We have 5 bytes of surrounding packet data */ - if ((0x05 + ECRYPTFS_SALT_SIZE - + key_rec->enc_key_size) >= max) { - ecryptfs_printk(KERN_ERR, "Authentication token is too " - "large\n"); +encrypted_session_key_set: + /* This format is inspired by OpenPGP; see RFC 2440 + * packet tag 3 */ + max_packet_size = (1 /* Tag 3 identifier */ + + 3 /* Max Tag 3 packet size */ + + 1 /* Version */ + + 1 /* Cipher code */ + + 1 /* S2K specifier */ + + 1 /* Hash identifier */ + + ECRYPTFS_SALT_SIZE /* Salt */ + + 1 /* Hash iterations */ + + key_rec->enc_key_size); /* Encrypted key size */ + if (max_packet_size > (*remaining_bytes)) { + printk(KERN_ERR "Packet too large; need up to [%d] bytes, but " + "there are only [%d] available\n", max_packet_size, + (*remaining_bytes)); rc = -EINVAL; goto out; } - /* This format is inspired by OpenPGP; see RFC 2440 - * packet tag 3 */ dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE; - /* ver+cipher+s2k+hash+salt+iter+enc_key */ - rc = write_packet_length(&dest[(*packet_size)], - (0x05 + ECRYPTFS_SALT_SIZE - + key_rec->enc_key_size), + /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3) + * to get the number of octets in the actual Tag 3 packet */ + rc = write_packet_length(&dest[(*packet_size)], (max_packet_size - 4), &packet_size_length); if (rc) { - ecryptfs_printk(KERN_ERR, "Error generating tag 3 packet " - "header; cannot generate packet length\n"); + printk(KERN_ERR "Error generating tag 3 packet header; cannot " + "generate packet length. rc = [%d]\n", rc); goto out; } (*packet_size) += packet_size_length; 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); if (cipher_code == 0) { ecryptfs_printk(KERN_WARNING, "Unable to generate code for " @@ -1631,10 +1751,10 @@ encrypted_session_key_set: key_rec->enc_key_size); (*packet_size) += key_rec->enc_key_size; out: - if (desc.tfm && !tfm_mutex) - crypto_free_blkcipher(desc.tfm); if (rc) (*packet_size) = 0; + else + (*remaining_bytes) -= (*packet_size); return rc; } @@ -1662,24 +1782,43 @@ ecryptfs_generate_key_packet_set(char *dest_base, size_t max) { struct ecryptfs_auth_tok *auth_tok; + struct ecryptfs_global_auth_tok *global_auth_tok; struct ecryptfs_mount_crypt_stat *mount_crypt_stat = &ecryptfs_superblock_to_private( ecryptfs_dentry->d_sb)->mount_crypt_stat; size_t written; struct ecryptfs_key_record *key_rec; + struct ecryptfs_key_sig *key_sig; int rc = 0; (*len) = 0; + mutex_lock(&crypt_stat->keysig_list_mutex); key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL); if (!key_rec) { rc = -ENOMEM; goto out; } - if (mount_crypt_stat->global_auth_tok) { - auth_tok = mount_crypt_stat->global_auth_tok; + list_for_each_entry(key_sig, &crypt_stat->keysig_list, + crypt_stat_list) { + memset(key_rec, 0, sizeof(*key_rec)); + rc = ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok, + mount_crypt_stat, + key_sig->keysig); + if (rc) { + printk(KERN_ERR "Error attempting to get the global " + "auth_tok; rc = [%d]\n", rc); + goto out_free; + } + if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID) { + printk(KERN_WARNING + "Skipping invalid auth tok with sig = [%s]\n", + global_auth_tok->sig); + continue; + } + auth_tok = global_auth_tok->global_auth_tok; if (auth_tok->token_type == ECRYPTFS_PASSWORD) { rc = write_tag_3_packet((dest_base + (*len)), - max, auth_tok, + &max, auth_tok, crypt_stat, key_rec, &written); if (rc) { @@ -1689,10 +1828,9 @@ ecryptfs_generate_key_packet_set(char *dest_base, } (*len) += written; /* Write auth tok signature packet */ - rc = write_tag_11_packet( - (dest_base + (*len)), - (max - (*len)), - key_rec->sig, ECRYPTFS_SIG_SIZE, &written); + rc = write_tag_11_packet((dest_base + (*len)), &max, + key_rec->sig, + ECRYPTFS_SIG_SIZE, &written); if (rc) { ecryptfs_printk(KERN_ERR, "Error writing " "auth tok signature packet\n"); @@ -1701,9 +1839,8 @@ ecryptfs_generate_key_packet_set(char *dest_base, (*len) += written; } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { rc = write_tag_1_packet(dest_base + (*len), - max, auth_tok, - crypt_stat,mount_crypt_stat, - key_rec, &written); + &max, auth_tok, + crypt_stat, key_rec, &written); if (rc) { ecryptfs_printk(KERN_WARNING, "Error " "writing tag 1 packet\n"); @@ -1716,19 +1853,69 @@ ecryptfs_generate_key_packet_set(char *dest_base, rc = -EINVAL; goto out_free; } - } else - BUG(); - if (likely((max - (*len)) > 0)) { + } + if (likely(max > 0)) { dest_base[(*len)] = 0x00; } else { ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n"); rc = -EIO; } - out_free: kmem_cache_free(ecryptfs_key_record_cache, key_rec); out: if (rc) (*len) = 0; + mutex_unlock(&crypt_stat->keysig_list_mutex); + return rc; +} + +struct kmem_cache *ecryptfs_key_sig_cache; + +int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig) +{ + struct ecryptfs_key_sig *new_key_sig; + int rc = 0; + + new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL); + if (!new_key_sig) { + rc = -ENOMEM; + printk(KERN_ERR + "Error allocating from ecryptfs_key_sig_cache\n"); + goto out; + } + memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX); + mutex_lock(&crypt_stat->keysig_list_mutex); + list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list); + mutex_unlock(&crypt_stat->keysig_list_mutex); +out: return rc; } + +struct kmem_cache *ecryptfs_global_auth_tok_cache; + +int +ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat, + char *sig) +{ + struct ecryptfs_global_auth_tok *new_auth_tok; + int rc = 0; + + new_auth_tok = kmem_cache_alloc(ecryptfs_global_auth_tok_cache, + GFP_KERNEL); + if (!new_auth_tok) { + rc = -ENOMEM; + printk(KERN_ERR "Error allocating from " + "ecryptfs_global_auth_tok_cache\n"); + goto out; + } + memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX); + new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0'; + mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex); + list_add(&new_auth_tok->mount_crypt_stat_list, + &mount_crypt_stat->global_auth_tok_list); + mount_crypt_stat->num_global_auth_toks++; + mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex); +out: + return rc; +} + diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index a98497264fe8..6e2170c96c02 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -179,38 +179,40 @@ static match_table_t tokens = { {ecryptfs_opt_err, NULL} }; -/** - * ecryptfs_verify_version - * @version: The version number to confirm - * - * Returns zero on good version; non-zero otherwise - */ -static int ecryptfs_verify_version(u16 version) +static int ecryptfs_init_global_auth_toks( + struct ecryptfs_mount_crypt_stat *mount_crypt_stat) { + struct ecryptfs_global_auth_tok *global_auth_tok; int rc = 0; - unsigned char major; - unsigned char minor; - - major = ((version >> 8) & 0xFF); - minor = (version & 0xFF); - if (major != ECRYPTFS_VERSION_MAJOR) { - ecryptfs_printk(KERN_ERR, "Major version number mismatch. " - "Expected [%d]; got [%d]\n", - ECRYPTFS_VERSION_MAJOR, major); - rc = -EINVAL; - goto out; - } - if (minor != ECRYPTFS_VERSION_MINOR) { - ecryptfs_printk(KERN_ERR, "Minor version number mismatch. " - "Expected [%d]; got [%d]\n", - ECRYPTFS_VERSION_MINOR, minor); - rc = -EINVAL; - goto out; + + list_for_each_entry(global_auth_tok, + &mount_crypt_stat->global_auth_tok_list, + mount_crypt_stat_list) { + if ((rc = ecryptfs_keyring_auth_tok_for_sig( + &global_auth_tok->global_auth_tok_key, + &global_auth_tok->global_auth_tok, + global_auth_tok->sig))) { + printk(KERN_ERR "Could not find valid key in user " + "session keyring for sig specified in mount " + "option: [%s]\n", global_auth_tok->sig); + global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; + rc = 0; + } else + global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; } -out: return rc; } +static void ecryptfs_init_mount_crypt_stat( + struct ecryptfs_mount_crypt_stat *mount_crypt_stat) +{ + memset((void *)mount_crypt_stat, 0, + sizeof(struct ecryptfs_mount_crypt_stat)); + INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); + mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); + mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; +} + /** * ecryptfs_parse_options * @sb: The ecryptfs super block @@ -264,14 +266,13 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options) case ecryptfs_opt_sig: case ecryptfs_opt_ecryptfs_sig: sig_src = args[0].from; - sig_dst = - mount_crypt_stat->global_auth_tok_sig; - memcpy(sig_dst, sig_src, ECRYPTFS_SIG_SIZE_HEX); - sig_dst[ECRYPTFS_SIG_SIZE_HEX] = '\0'; - ecryptfs_printk(KERN_DEBUG, - "The mount_crypt_stat " - "global_auth_tok_sig set to: " - "[%s]\n", sig_dst); + rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, + sig_src); + if (rc) { + printk(KERN_ERR "Error attempting to register " + "global sig; rc = [%d]\n", rc); + goto out; + } sig_set = 1; break; case ecryptfs_opt_debug: @@ -358,55 +359,21 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options) if (!cipher_key_bytes_set) { mount_crypt_stat->global_default_cipher_key_size = 0; } - rc = ecryptfs_process_cipher( - &mount_crypt_stat->global_key_tfm, - mount_crypt_stat->global_default_cipher_name, - &mount_crypt_stat->global_default_cipher_key_size); - if (rc) { - printk(KERN_ERR "Error attempting to initialize cipher [%s] " - "with key size [%Zd] bytes; rc = [%d]\n", + if ((rc = ecryptfs_add_new_key_tfm( + NULL, mount_crypt_stat->global_default_cipher_name, + mount_crypt_stat->global_default_cipher_key_size))) { + printk(KERN_ERR "Error attempting to initialize cipher with " + "name = [%s] and key size = [%d]; rc = [%d]\n", mount_crypt_stat->global_default_cipher_name, mount_crypt_stat->global_default_cipher_key_size, rc); - mount_crypt_stat->global_key_tfm = NULL; - mount_crypt_stat->global_auth_tok_key = NULL; - rc = -EINVAL; - goto out; - } - mutex_init(&mount_crypt_stat->global_key_tfm_mutex); - ecryptfs_printk(KERN_DEBUG, "Requesting the key with description: " - "[%s]\n", mount_crypt_stat->global_auth_tok_sig); - /* The reference to this key is held until umount is done The - * call to key_put is done in ecryptfs_put_super() */ - auth_tok_key = request_key(&key_type_user, - mount_crypt_stat->global_auth_tok_sig, - NULL); - if (!auth_tok_key || IS_ERR(auth_tok_key)) { - ecryptfs_printk(KERN_ERR, "Could not find key with " - "description: [%s]\n", - mount_crypt_stat->global_auth_tok_sig); - process_request_key_err(PTR_ERR(auth_tok_key)); rc = -EINVAL; goto out; } - auth_tok = ecryptfs_get_key_payload_data(auth_tok_key); - if (ecryptfs_verify_version(auth_tok->version)) { - ecryptfs_printk(KERN_ERR, "Data structure version mismatch. " - "Userspace tools must match eCryptfs kernel " - "module with major version [%d] and minor " - "version [%d]\n", ECRYPTFS_VERSION_MAJOR, - ECRYPTFS_VERSION_MINOR); - rc = -EINVAL; - goto out; - } - if (auth_tok->token_type != ECRYPTFS_PASSWORD - && auth_tok->token_type != ECRYPTFS_PRIVATE_KEY) { - ecryptfs_printk(KERN_ERR, "Invalid auth_tok structure " - "returned from key query\n"); - rc = -EINVAL; - goto out; + if ((rc = ecryptfs_init_global_auth_toks(mount_crypt_stat))) { + printk(KERN_WARNING "One or more global auth toks could not " + "properly register; rc = [%d]\n", rc); } - mount_crypt_stat->global_auth_tok_key = auth_tok_key; - mount_crypt_stat->global_auth_tok = auth_tok; + rc = 0; out: return rc; } |