[PATCH 3/6] eCryptfs: Cipher code to new crypto API

Michael Halcrow
2006-10-30T23:36:41Z

Update cipher block encryption code to the new crypto API.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>

---

fs/ecryptfs/crypto.c | 92 +++++++++++++++++++++++++++++--------
fs/ecryptfs/ecryptfs_kernel.h | 9 ++--
fs/ecryptfs/keystore.c | 101 +++++++++++++++++++++++++++--------------
fs/ecryptfs/main.c | 2 +
4 files changed, 146 insertions(+), 58 deletions(-)

401d3201a0ae8ff009eb1c363bef192ca06797b0
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index f14c5a3..7f32fcb 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -123,6 +123,28 @@ out:
return rc;
}

+int ecryptfs_crypto_api_algify_cipher_name(char **algified_name,
+ char *cipher_name,
+ char *chaining_modifier)
+{
+ int cipher_name_len = strlen(cipher_name);
+ int chaining_modifier_len = strlen(chaining_modifier);
+ int algified_name_len;
+ int rc;
+
+ algified_name_len = (chaining_modifier_len + cipher_name_len + 3);
+ (*algified_name) = kmalloc(algified_name_len, GFP_KERNEL);
+ if (!(algified_name)) {
+ rc = -ENOMEM;
+ goto out;
+ }
+ snprintf((*algified_name), algified_name_len, "%s(%s)",
+ chaining_modifier, cipher_name);
+ rc = 0;
+out:
+ return rc;
+}
+
/**
* ecryptfs_derive_iv
* @iv: destination for the derived iv vale
@@ -197,7 +219,7 @@ ecryptfs_init_crypt_stat(struct ecryptfs
void ecryptfs_destruct_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat)
{
if (crypt_stat->tfm)
- crypto_free_tfm(crypt_stat->tfm);
+ crypto_free_blkcipher(crypt_stat->tfm);
if (crypt_stat->hash_tfm)
crypto_free_hash(crypt_stat->hash_tfm);
memset(crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat));
@@ -209,7 +231,7 @@ void ecryptfs_destruct_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_tfm(mount_crypt_stat->global_key_tfm);
+ crypto_free_blkcipher(mount_crypt_stat->global_key_tfm);
memset(mount_crypt_stat, 0, sizeof(struct ecryptfs_mount_crypt_stat));
}

@@ -275,6 +297,11 @@ static int encrypt_scatterlist(struct ec
struct scatterlist *src_sg, int size,
unsigned char *iv)
{
+ struct blkcipher_desc desc = {
+ .tfm = crypt_stat->tfm,
+ .info = iv,
+ .flags = CRYPTO_TFM_REQ_MAY_SLEEP
+ };
int rc = 0;

BUG_ON(!crypt_stat || !crypt_stat->tfm
@@ -288,8 +315,8 @@ static int encrypt_scatterlist(struct ec
}
/* Consider doing this once, when the file is opened */
mutex_lock(&crypt_stat->cs_tfm_mutex);
- rc = crypto_cipher_setkey(crypt_stat->tfm, crypt_stat->key,
- crypt_stat->key_size);
+ rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key,
+ crypt_stat->key_size);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n",
rc);
@@ -298,7 +325,7 @@ static int encrypt_scatterlist(struct ec
goto out;
}
ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes.\n", size);
- crypto_cipher_encrypt_iv(crypt_stat->tfm, dest_sg, src_sg, size, iv);
+ crypto_blkcipher_encrypt_iv(&desc, dest_sg, src_sg, size);
mutex_unlock(&crypt_stat->cs_tfm_mutex);
out:
return rc;
@@ -681,12 +708,17 @@ static int decrypt_scatterlist(struct ec
struct scatterlist *src_sg, int size,
unsigned char *iv)
{
+ struct blkcipher_desc desc = {
+ .tfm = crypt_stat->tfm,
+ .info = iv,
+ .flags = CRYPTO_TFM_REQ_MAY_SLEEP
+ };
int rc = 0;

/* Consider doing this once, when the file is opened */
mutex_lock(&crypt_stat->cs_tfm_mutex);
- rc = crypto_cipher_setkey(crypt_stat->tfm, crypt_stat->key,
- crypt_stat->key_size);
+ rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key,
+ crypt_stat->key_size);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n",
rc);
@@ -695,8 +727,7 @@ static int decrypt_scatterlist(struct ec
goto out;
}
ecryptfs_printk(KERN_DEBUG, "Decrypting [%d] bytes.\n", size);
- rc = crypto_cipher_decrypt_iv(crypt_stat->tfm, dest_sg, src_sg, size,
- iv);
+ rc = crypto_blkcipher_decrypt_iv(&desc, dest_sg, src_sg, size);
mutex_unlock(&crypt_stat->cs_tfm_mutex);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error decrypting; rc = [%d]\n",
@@ -765,6 +796,7 @@ #define ECRYPTFS_MAX_SCATTERLIST_LEN 4
*/
int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat)
{
+ char *full_alg_name;
int rc = -EINVAL;

if (!crypt_stat->cipher) {
@@ -781,16 +813,24 @@ int ecryptfs_init_crypt_ctx(struct ecryp
goto out;
}
mutex_lock(&crypt_stat->cs_tfm_mutex);
- crypt_stat->tfm = crypto_alloc_tfm(crypt_stat->cipher,
- ECRYPTFS_DEFAULT_CHAINING_MODE
- | CRYPTO_TFM_REQ_WEAK_KEY);
- mutex_unlock(&crypt_stat->cs_tfm_mutex);
+ rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name,
+ crypt_stat->cipher, "cbc");
+ if (rc)
+ goto out;
+ crypt_stat->tfm = crypto_alloc_blkcipher(full_alg_name, 0,
+ CRYPTO_ALG_ASYNC);
+ kfree(full_alg_name);
if (!crypt_stat->tfm) {
ecryptfs_printk(KERN_ERR, "cryptfs: init_crypt_ctx(): "
"Error initializing cipher [%s]\n",
crypt_stat->cipher);
+ mutex_unlock(&crypt_stat->cs_tfm_mutex);
goto out;
}
+ crypto_blkcipher_set_flags(crypt_stat->tfm,
+ (ECRYPTFS_DEFAULT_CHAINING_MODE
+ | CRYPTO_TFM_REQ_WEAK_KEY));
+ mutex_unlock(&crypt_stat->cs_tfm_mutex);
rc = 0;
out:
return rc;
@@ -1588,10 +1628,11 @@ out:
* event, regardless of whether this function succeeds for fails.
*/
int
-ecryptfs_process_cipher(struct crypto_tfm **key_tfm, char *cipher_name,
+ecryptfs_process_cipher(struct crypto_blkcipher **key_tfm, char *cipher_name,
size_t *key_size)
{
char dummy_key[ECRYPTFS_MAX_KEY_BYTES];
+ char *full_alg_name;
int rc;

*key_tfm = NULL;
@@ -1601,17 +1642,26 @@ ecryptfs_process_cipher(struct crypto_tf
"allowable is [%d]\n", *key_size, ECRYPTFS_MAX_KEY_BYTES);
goto out;
}
- *key_tfm = crypto_alloc_tfm(cipher_name, CRYPTO_TFM_REQ_WEAK_KEY);
- if (!(*key_tfm)) {
- rc = -EINVAL;
+ rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name, cipher_name,
+ "ecb");
+ if (rc)
+ goto out;
+ *key_tfm = crypto_alloc_blkcipher(full_alg_name, 0, CRYPTO_ALG_ASYNC);
+ kfree(full_alg_name);
+ if (IS_ERR(*key_tfm)) {
+ rc = PTR_ERR(*key_tfm);
printk(KERN_ERR "Unable to allocate crypto cipher with name "
- "[%s]\n", cipher_name);
+ "[%s]; rc = [%d]\n", cipher_name, rc);
goto out;
}
- if (*key_size == 0)
- *key_size = crypto_tfm_alg_max_keysize(*key_tfm);
+ crypto_blkcipher_set_flags(*key_tfm, CRYPTO_TFM_REQ_WEAK_KEY);
+ if (*key_size == 0) {
+ struct blkcipher_alg *alg = crypto_blkcipher_alg(*key_tfm);
+
+ *key_size = alg->max_keysize;
+ }
get_random_bytes(dummy_key, *key_size);
- rc = crypto_cipher_setkey(*key_tfm, dummy_key, *key_size);
+ rc = crypto_blkcipher_setkey(*key_tfm, dummy_key, *key_size);
if (rc) {
printk(KERN_ERR "Error attempting to set key of size [%Zd] for "
"cipher [%s]; rc = [%d]\n", *key_size, cipher_name, rc);
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 840aa01..199fcda 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -205,7 +205,7 @@ #define ECRYPTFS_KEY_VALID 0x00
size_t extent_shift;
unsigned int extent_mask;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
- struct crypto_tfm *tfm;
+ struct crypto_blkcipher *tfm;
struct crypto_hash *hash_tfm; /* Crypto context for generating
* the initialization vectors */
unsigned char cipher[ECRYPTFS_MAX_CIPHER_NAME_SIZE];
@@ -245,7 +245,7 @@ #define ECRYPTFS_PLAINTEXT_PASSTHROUGH_E
struct ecryptfs_auth_tok *global_auth_tok;
struct key *global_auth_tok_key;
size_t global_default_cipher_key_size;
- struct crypto_tfm *global_key_tfm;
+ struct crypto_blkcipher *global_key_tfm;
struct mutex global_key_tfm_mutex;
unsigned char global_default_cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE
+ 1];
@@ -426,6 +426,9 @@ void ecryptfs_destruct_crypt_stat(struct
void ecryptfs_destruct_mount_crypt_stat(
struct ecryptfs_mount_crypt_stat *mount_crypt_stat);
int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat);
+int ecryptfs_crypto_api_algify_cipher_name(char **algified_name,
+ char *cipher_name,
+ char *chaining_modifier);
int ecryptfs_write_inode_size_to_header(struct file *lower_file,
struct inode *lower_inode,
struct inode *inode);
@@ -474,7 +477,7 @@ ecryptfs_parse_packet_set(struct ecryptf
unsigned char *src, struct dentry *ecryptfs_dentry);
int ecryptfs_truncate(struct dentry *dentry, loff_t new_length);
int
-ecryptfs_process_cipher(struct crypto_tfm **key_tfm, char *cipher_name,
+ecryptfs_process_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);
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index bc706d3..8a9ff86 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -458,14 +458,16 @@ out:
static int decrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
struct ecryptfs_crypt_stat *crypt_stat)
{
- int rc = 0;
struct ecryptfs_password *password_s_ptr;
- struct crypto_tfm *tfm = NULL;
struct scatterlist src_sg[2], dst_sg[2];
struct mutex *tfm_mutex = NULL;
/* TODO: Use virt_to_scatterlist for these */
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 (ECRYPTFS_CHECK_FLAG(password_s_ptr->flags,
@@ -482,22 +484,32 @@ static int decrypt_session_key(struct ec
if (!strcmp(crypt_stat->cipher,
crypt_stat->mount_crypt_stat->global_default_cipher_name)
&& crypt_stat->mount_crypt_stat->global_key_tfm) {
- tfm = 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 {
- tfm = crypto_alloc_tfm(crypt_stat->cipher,
- CRYPTO_TFM_REQ_WEAK_KEY);
- if (!tfm) {
- printk(KERN_ERR "Error allocating crypto context\n");
- rc = -ENOMEM;
+ 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 (tfm_mutex)
mutex_lock(tfm_mutex);
- rc = crypto_cipher_setkey(tfm,
- password_s_ptr->session_key_encryption_key,
- crypt_stat->key_size);
+ rc = crypto_blkcipher_setkey(desc.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;
@@ -528,9 +540,12 @@ static int decrypt_session_key(struct ec
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;
- /* TODO: Handle error condition */
- crypto_cipher_decrypt(tfm, dst_sg, src_sg,
- auth_tok->session_key.encrypted_key_size);
+ rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg,
+ auth_tok->session_key.encrypted_key_size);
+ if (rc) {
+ printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc);
+ goto out_free_memory;
+ }
auth_tok->session_key.decrypted_key_size =
auth_tok->session_key.encrypted_key_size;
memcpy(auth_tok->session_key.decrypted_key, session_key,
@@ -543,6 +558,7 @@ static int decrypt_session_key(struct ec
if (ecryptfs_verbosity > 0)
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);
@@ -551,7 +567,7 @@ out_free_tfm:
if (tfm_mutex)
mutex_unlock(tfm_mutex);
else
- crypto_free_tfm(tfm);
+ crypto_free_blkcipher(desc.tfm);
out:
return rc;
}
@@ -800,19 +816,21 @@ write_tag_3_packet(char *dest, size_t ma
struct ecryptfs_crypt_stat *crypt_stat,
struct ecryptfs_key_record *key_rec, size_t *packet_size)
{
- int rc = 0;
-
size_t i;
size_t signature_is_valid = 0;
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 crypto_tfm *tfm = NULL;
struct mutex *tfm_mutex = NULL;
size_t key_rec_size;
size_t packet_size_length;
size_t cipher_code;
+ struct blkcipher_desc desc = {
+ .tfm = NULL,
+ .flags = CRYPTO_TFM_REQ_MAY_SLEEP
+ };
+ int rc = 0;

(*packet_size) = 0;
/* Check for a valid signature on the auth_tok */
@@ -879,33 +897,48 @@ write_tag_3_packet(char *dest, size_t ma
if (!strcmp(crypt_stat->cipher,
crypt_stat->mount_crypt_stat->global_default_cipher_name)
&& crypt_stat->mount_crypt_stat->global_key_tfm) {
- tfm = 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
- tfm = crypto_alloc_tfm(crypt_stat->cipher, 0);
- if (!tfm) {
- ecryptfs_printk(KERN_ERR, "Could not initialize crypto "
- "context for cipher [%s]\n",
- crypt_stat->cipher);
- rc = -EINVAL;
- goto out;
+ } 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);
- rc = crypto_cipher_setkey(tfm, session_key_encryption_key,
- crypt_stat->key_size);
+ rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key,
+ crypt_stat->key_size);
if (rc < 0) {
if (tfm_mutex)
mutex_unlock(tfm_mutex);
ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
- "context\n");
+ "context; rc = [%d]\n", rc);
goto out;
}
rc = 0;
ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n",
crypt_stat->key_size);
- crypto_cipher_encrypt(tfm, dest_sg, src_sg,
- (*key_rec).enc_key_size);
+ rc = crypto_blkcipher_encrypt(&desc, dest_sg, src_sg,
+ (*key_rec).enc_key_size);
+ 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");
@@ -968,8 +1001,8 @@ encrypted_session_key_set:
(*key_rec).enc_key_size);
(*packet_size) += (*key_rec).enc_key_size;
out:
- if (tfm && !tfm_mutex)
- crypto_free_tfm(tfm);
+ if (desc.tfm && !tfm_mutex)
+ crypto_free_blkcipher(desc.tfm);
if (rc)
(*packet_size) = 0;
return rc;
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index a65f486..a78d87d 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -315,6 +315,8 @@ static int ecryptfs_parse_options(struct
"with key size [%Zd] bytes; 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;
}
--
1.3.3