Commit e5d9cbde authored by Michael Halcrow's avatar Michael Halcrow Committed by Linus Torvalds

[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: default avatarMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 4a279ff1
......@@ -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;
}
......
......@@ -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);
......
......@@ -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) {
......
......@@ -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",
......
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