From e5d9cbde6ce0001e49994df5fcdcbeff8be8037b Mon Sep 17 00:00:00 2001 From: Michael Halcrow Date: Mon, 30 Oct 2006 22:07:16 -0800 Subject: [PATCH] eCryptfs: Clean up crypto initialization Clean up the crypto initialization code; let the crypto API take care of the key size checks. Signed-off-by: Michael Halcrow Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/crypto.c | 66 ++++++++----------------------------------- fs/ecryptfs/ecryptfs_kernel.h | 4 +-- fs/ecryptfs/keystore.c | 19 ++++++------- fs/ecryptfs/main.c | 13 ++------- 4 files changed, 24 insertions(+), 78 deletions(-) (limited to 'fs/ecryptfs') diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index ed35a9712fa1..82e7d02cefae 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -1573,35 +1573,26 @@ out: /** * ecryptfs_process_cipher - Perform cipher initialization. - * @tfm: Crypto context set by this function * @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. + * @cipher_name: Name of the cipher + * @key_size: Size of the key in bytes * * Returns zero on success. Any crypto_tfm structs allocated here * should be released by other functions, such as on a superblock put * event, regardless of whether this function succeeds for fails. */ int -ecryptfs_process_cipher(struct crypto_tfm **tfm, struct crypto_tfm **key_tfm, - char *cipher_name, size_t key_size) +ecryptfs_process_cipher(struct crypto_tfm **key_tfm, char *cipher_name, + size_t *key_size) { char dummy_key[ECRYPTFS_MAX_KEY_BYTES]; int rc; - *tfm = *key_tfm = NULL; - if (key_size > ECRYPTFS_MAX_KEY_BYTES) { + *key_tfm = NULL; + if (*key_size > ECRYPTFS_MAX_KEY_BYTES) { rc = -EINVAL; printk(KERN_ERR "Requested key size is [%Zd] bytes; maximum " - "allowable is [%d]\n", key_size, ECRYPTFS_MAX_KEY_BYTES); - goto out; - } - *tfm = crypto_alloc_tfm(cipher_name, (ECRYPTFS_DEFAULT_CHAINING_MODE - | CRYPTO_TFM_REQ_WEAK_KEY)); - if (!(*tfm)) { - rc = -EINVAL; - printk(KERN_ERR "Unable to allocate crypto cipher with name " - "[%s]\n", cipher_name); + "allowable is [%d]\n", *key_size, ECRYPTFS_MAX_KEY_BYTES); goto out; } *key_tfm = crypto_alloc_tfm(cipher_name, CRYPTO_TFM_REQ_WEAK_KEY); @@ -1611,46 +1602,13 @@ ecryptfs_process_cipher(struct crypto_tfm **tfm, struct crypto_tfm **key_tfm, "[%s]\n", cipher_name); goto out; } - if (key_size < crypto_tfm_alg_min_keysize(*tfm)) { - rc = -EINVAL; - printk(KERN_ERR "Request key size is [%Zd]; minimum key size " - "supported by cipher [%s] is [%d]\n", key_size, - cipher_name, crypto_tfm_alg_min_keysize(*tfm)); - goto out; - } - if (key_size < crypto_tfm_alg_min_keysize(*key_tfm)) { - rc = -EINVAL; - printk(KERN_ERR "Request key size is [%Zd]; minimum key size " - "supported by cipher [%s] is [%d]\n", key_size, - cipher_name, crypto_tfm_alg_min_keysize(*key_tfm)); - goto out; - } - if (key_size > crypto_tfm_alg_max_keysize(*tfm)) { - rc = -EINVAL; - printk(KERN_ERR "Request key size is [%Zd]; maximum key size " - "supported by cipher [%s] is [%d]\n", key_size, - cipher_name, crypto_tfm_alg_min_keysize(*tfm)); - goto out; - } - if (key_size > crypto_tfm_alg_max_keysize(*key_tfm)) { - rc = -EINVAL; - printk(KERN_ERR "Request key size is [%Zd]; maximum key size " - "supported by cipher [%s] is [%d]\n", key_size, - cipher_name, crypto_tfm_alg_min_keysize(*key_tfm)); - goto out; - } - get_random_bytes(dummy_key, key_size); - rc = crypto_cipher_setkey(*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); - rc = -EINVAL; - goto out; - } - rc = crypto_cipher_setkey(*key_tfm, dummy_key, key_size); + if (*key_size == 0) + *key_size = crypto_tfm_alg_max_keysize(*key_tfm); + get_random_bytes(dummy_key, *key_size); + rc = crypto_cipher_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); + "cipher [%s]; rc = [%d]\n", *key_size, cipher_name, rc); rc = -EINVAL; goto out; } diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index 872c9958531a..4112df9dec50 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -473,8 +473,8 @@ 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_tfm **tfm, struct crypto_tfm **key_tfm, - char *cipher_name, size_t key_size); +ecryptfs_process_cipher(struct crypto_tfm **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); diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c index ba454785a0c5..bc706d33559a 100644 --- a/fs/ecryptfs/keystore.c +++ b/fs/ecryptfs/keystore.c @@ -493,19 +493,16 @@ static int decrypt_session_key(struct ecryptfs_auth_tok *auth_tok, goto out; } } - if (password_s_ptr->session_key_encryption_key_bytes - < crypto_tfm_alg_min_keysize(tfm)) { - printk(KERN_WARNING "Session key encryption key is [%d] bytes; " - "minimum keysize for selected cipher is [%d] bytes.\n", - password_s_ptr->session_key_encryption_key_bytes, - crypto_tfm_alg_min_keysize(tfm)); - rc = -EINVAL; - goto out; - } if (tfm_mutex) mutex_lock(tfm_mutex); - crypto_cipher_setkey(tfm, password_s_ptr->session_key_encryption_key, - crypt_stat->key_size); + rc = crypto_cipher_setkey(tfm, + password_s_ptr->session_key_encryption_key, + crypt_stat->key_size); + if (rc < 0) { + 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) { diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index 5938a232d11b..a65f4865182c 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -208,7 +208,6 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options) char *cipher_name_dst; char *cipher_name_src; char *cipher_key_bytes_src; - struct crypto_tfm *tmp_tfm; int cipher_name_len; if (!options) { @@ -305,20 +304,12 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options) = '\0'; } if (!cipher_key_bytes_set) { - mount_crypt_stat->global_default_cipher_key_size = - ECRYPTFS_DEFAULT_KEY_BYTES; - ecryptfs_printk(KERN_DEBUG, "Cipher key size was not " - "specified. Defaulting to [%d]\n", - mount_crypt_stat-> - global_default_cipher_key_size); + mount_crypt_stat->global_default_cipher_key_size = 0; } rc = ecryptfs_process_cipher( - &tmp_tfm, &mount_crypt_stat->global_key_tfm, mount_crypt_stat->global_default_cipher_name, - mount_crypt_stat->global_default_cipher_key_size); - if (tmp_tfm) - crypto_free_tfm(tmp_tfm); + &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", -- cgit v1.2.3-59-g8ed1b