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Commit a8ca90e2 authored by Tyler Hicks's avatar Tyler Hicks
Browse files

eCryptfs: Combine page_offset crypto functions 



Combine ecryptfs_encrypt_page_offset() and
ecryptfs_decrypt_page_offset(). These two functions are functionally
identical so they can be safely merged if the caller can indicate
whether an encryption or decryption operation should occur.

Signed-off-by: default avatarTyler Hicks <tyhicks@canonical.com>
parent 00a69940

fs/ecryptfs/crypto.c

+18 −51
Original line number Diff line number Diff line
@@ -40,14 +40,9 @@ 
#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,

			     int offset, int size, unsigned char *iv);

static int

ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat,

static int crypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat,

			     struct page *dst_page, struct page *src_page,

			     int offset, int size, unsigned char *iv);

			     int offset, int size, unsigned char *iv, int op);



/**

 * ecryptfs_to_hex
@@ -452,9 +447,9 @@ static int ecryptfs_encrypt_extent(struct page *enc_extent_page, 
			(unsigned long long)(extent_base + extent_offset), rc);

		goto out;

	}

	rc = ecryptfs_encrypt_page_offset(crypt_stat, enc_extent_page, page,

					extent_offset * crypt_stat->extent_size,

					crypt_stat->extent_size, extent_iv);

	rc = crypt_page_offset(crypt_stat, enc_extent_page, page,

			       (extent_offset * crypt_stat->extent_size),

			       crypt_stat->extent_size, extent_iv, ENCRYPT);

	if (rc < 0) {

		printk(KERN_ERR "%s: Error attempting to encrypt page with "

		       "page->index = [%ld], extent_offset = [%ld]; "
@@ -555,9 +550,9 @@ static int ecryptfs_decrypt_extent(struct page *page, 
			(unsigned long long)(extent_base + extent_offset), rc);

		goto out;

	}

	rc = ecryptfs_decrypt_page_offset(crypt_stat, page, enc_extent_page,

					extent_offset * crypt_stat->extent_size,

					crypt_stat->extent_size, extent_iv);

	rc = crypt_page_offset(crypt_stat, page, enc_extent_page,

			       (extent_offset * crypt_stat->extent_size),

			       crypt_stat->extent_size, extent_iv, DECRYPT);

	if (rc < 0) {

		printk(KERN_ERR "%s: Error attempting to decrypt to page with "

		       "page->index = [%ld], extent_offset = [%ld]; "
@@ -628,20 +623,20 @@ out: 
}



/**

 * ecryptfs_encrypt_page_offset

 * crypt_page_offset

 * @crypt_stat: The cryptographic context

 * @dst_page: The page to encrypt into

 * @src_page: The page to encrypt from

 * @dst_page: The page to write the result into

 * @src_page: The page to read from

 * @offset: The byte offset into the dst_page and src_page

 * @size: The number of bytes to encrypt

 * @iv: The initialization vector to use for the encryption

 * @size: The number of bytes of data

 * @iv: The initialization vector to use for the crypto operation

 * @op: ENCRYPT or DECRYPT to indicate the desired operation

 *

 * Returns the number of bytes encrypted

 * Returns the number of bytes encrypted or decrypted

 */

static int

ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat,

static int crypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat,

			     struct page *dst_page, struct page *src_page,

			     int offset, int size, unsigned char *iv)

			     int offset, int size, unsigned char *iv, int op)

{

	struct scatterlist src_sg, dst_sg;
@@ -650,36 +645,8 @@ ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat, 


	sg_set_page(&src_sg, src_page, size, offset);

	sg_set_page(&dst_sg, dst_page, size, offset);

	return crypt_scatterlist(crypt_stat, &dst_sg, &src_sg,

				 size, iv, ENCRYPT);

}



/**

 * ecryptfs_decrypt_page_offset

 * @crypt_stat: The cryptographic context

 * @dst_page: The page to decrypt into

 * @src_page: The page to decrypt from

 * @offset: The byte offset into the dst_page and src_page

 * @size: The number of bytes to decrypt

 * @iv: The initialization vector to use for the decryption

 *

 * Returns the number of bytes decrypted

 */

static int

ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat,

			     struct page *dst_page, struct page *src_page,

			     int offset, int size, unsigned char *iv)

{

	struct scatterlist src_sg, dst_sg;



	sg_init_table(&src_sg, 1);

	sg_set_page(&src_sg, src_page, size, offset);



	sg_init_table(&dst_sg, 1);

	sg_set_page(&dst_sg, dst_page, size, offset);



	return crypt_scatterlist(crypt_stat, &dst_sg, &src_sg,

				 size, iv, DECRYPT);

	return crypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv, op);

}



#define ECRYPTFS_MAX_SCATTERLIST_LEN 4