eCryptfs: Combine encrypt_scatterlist() and decrypt_scatterlist()
These two functions are identical except for a debug printk and whether
they call crypto_ablkcipher_encrypt() or crypto_ablkcipher_decrypt(), so
they can be safely merged if the caller can indicate if encryption or
decryption should occur.
The debug printk is useless so it is removed.
Two new #define's are created to indicate if an ENCRYPT or DECRYPT
operation is desired.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 35b409b..fb54a01 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -37,6 +37,9 @@
#include <asm/unaligned.h>
#include "ecryptfs_kernel.h"
+#define DECRYPT 0
+#define ENCRYPT 1
+
static int
ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat,
struct page *dst_page, struct page *src_page,
@@ -334,19 +337,20 @@
}
/**
- * encrypt_scatterlist
+ * crypt_scatterlist
* @crypt_stat: Pointer to the crypt_stat struct to initialize.
- * @dest_sg: Destination of encrypted data
- * @src_sg: Data to be encrypted
- * @size: Length of data to be encrypted
- * @iv: iv to use during encryption
+ * @dest_sg: Destination of the data after performing the crypto operation
+ * @src_sg: Data to be encrypted or decrypted
+ * @size: Length of data
+ * @iv: IV to use
+ * @op: ENCRYPT or DECRYPT to indicate the desired operation
*
- * Returns the number of bytes encrypted; negative value on error
+ * Returns the number of bytes encrypted or decrypted; negative value on error
*/
-static int encrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat,
- struct scatterlist *dest_sg,
- struct scatterlist *src_sg, int size,
- unsigned char *iv)
+static int crypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat,
+ struct scatterlist *dest_sg,
+ struct scatterlist *src_sg, int size,
+ unsigned char *iv, int op)
{
struct ablkcipher_request *req = NULL;
struct extent_crypt_result ecr;
@@ -389,9 +393,9 @@
crypt_stat->flags |= ECRYPTFS_KEY_SET;
}
mutex_unlock(&crypt_stat->cs_tfm_mutex);
- ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes.\n", size);
ablkcipher_request_set_crypt(req, src_sg, dest_sg, size, iv);
- rc = crypto_ablkcipher_encrypt(req);
+ rc = op == ENCRYPT ? crypto_ablkcipher_encrypt(req) :
+ crypto_ablkcipher_decrypt(req);
if (rc == -EINPROGRESS || rc == -EBUSY) {
struct extent_crypt_result *ecr = req->base.data;
@@ -624,78 +628,6 @@
}
/**
- * decrypt_scatterlist
- * @crypt_stat: Cryptographic context
- * @dest_sg: The destination scatterlist to decrypt into
- * @src_sg: The source scatterlist to decrypt from
- * @size: The number of bytes to decrypt
- * @iv: The initialization vector to use for the decryption
- *
- * Returns the number of bytes decrypted; negative value on error
- */
-static int decrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat,
- struct scatterlist *dest_sg,
- struct scatterlist *src_sg, int size,
- unsigned char *iv)
-{
- struct ablkcipher_request *req = NULL;
- struct extent_crypt_result ecr;
- int rc = 0;
-
- BUG_ON(!crypt_stat || !crypt_stat->tfm
- || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED));
- if (unlikely(ecryptfs_verbosity > 0)) {
- ecryptfs_printk(KERN_DEBUG, "Key size [%zd]; key:\n",
- crypt_stat->key_size);
- ecryptfs_dump_hex(crypt_stat->key,
- crypt_stat->key_size);
- }
-
- init_completion(&ecr.completion);
-
- mutex_lock(&crypt_stat->cs_tfm_mutex);
- req = ablkcipher_request_alloc(crypt_stat->tfm, GFP_NOFS);
- if (!req) {
- mutex_unlock(&crypt_stat->cs_tfm_mutex);
- rc = -ENOMEM;
- goto out;
- }
-
- ablkcipher_request_set_callback(req,
- CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
- extent_crypt_complete, &ecr);
- /* Consider doing this once, when the file is opened */
- if (!(crypt_stat->flags & ECRYPTFS_KEY_SET)) {
- rc = crypto_ablkcipher_setkey(crypt_stat->tfm, crypt_stat->key,
- crypt_stat->key_size);
- if (rc) {
- ecryptfs_printk(KERN_ERR,
- "Error setting key; rc = [%d]\n",
- rc);
- mutex_unlock(&crypt_stat->cs_tfm_mutex);
- rc = -EINVAL;
- goto out;
- }
- crypt_stat->flags |= ECRYPTFS_KEY_SET;
- }
- mutex_unlock(&crypt_stat->cs_tfm_mutex);
- ecryptfs_printk(KERN_DEBUG, "Decrypting [%d] bytes.\n", size);
- ablkcipher_request_set_crypt(req, src_sg, dest_sg, size, iv);
- rc = crypto_ablkcipher_decrypt(req);
- if (rc == -EINPROGRESS || rc == -EBUSY) {
- struct extent_crypt_result *ecr = req->base.data;
-
- wait_for_completion(&ecr->completion);
- rc = ecr->rc;
- INIT_COMPLETION(ecr->completion);
- }
-out:
- ablkcipher_request_free(req);
- return rc;
-
-}
-
-/**
* ecryptfs_encrypt_page_offset
* @crypt_stat: The cryptographic context
* @dst_page: The page to encrypt into
@@ -718,7 +650,8 @@
sg_set_page(&src_sg, src_page, size, offset);
sg_set_page(&dst_sg, dst_page, size, offset);
- return encrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv);
+ return crypt_scatterlist(crypt_stat, &dst_sg, &src_sg,
+ size, iv, ENCRYPT);
}
/**
@@ -745,7 +678,8 @@
sg_init_table(&dst_sg, 1);
sg_set_page(&dst_sg, dst_page, size, offset);
- return decrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv);
+ return crypt_scatterlist(crypt_stat, &dst_sg, &src_sg,
+ size, iv, DECRYPT);
}
#define ECRYPTFS_MAX_SCATTERLIST_LEN 4