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Diffstat (limited to 'fs/ecryptfs/crypto.c')
-rw-r--r--fs/ecryptfs/crypto.c74
1 files changed, 20 insertions, 54 deletions
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 609efc01d5c2..9845d2fd2506 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -416,28 +416,29 @@ static loff_t lower_offset_for_page(struct ecryptfs_crypt_stat *crypt_stat,
}
/**
- * ecryptfs_encrypt_extent
- * @enc_extent_page: Allocated page into which to encrypt the data in
- * @page
+ * crypt_extent
+ * @dst_page: The page to write the result into
* @crypt_stat: crypt_stat containing cryptographic context for the
* encryption operation
- * @page: Page containing plaintext data extent to encrypt
+ * @src_page: The page to read from
* @extent_offset: Page extent offset for use in generating IV
+ * @op: ENCRYPT or DECRYPT to indicate the desired operation
*
- * Encrypts one extent of data.
+ * Encrypts or decrypts one extent of data.
*
* Return zero on success; non-zero otherwise
*/
-static int ecryptfs_encrypt_extent(struct page *enc_extent_page,
- struct ecryptfs_crypt_stat *crypt_stat,
- struct page *page,
- unsigned long extent_offset)
+static int crypt_extent(struct page *dst_page,
+ struct ecryptfs_crypt_stat *crypt_stat,
+ struct page *src_page,
+ unsigned long extent_offset, int op)
{
+ pgoff_t page_index = op == ENCRYPT ? src_page->index : dst_page->index;
loff_t extent_base;
char extent_iv[ECRYPTFS_MAX_IV_BYTES];
int rc;
- extent_base = (((loff_t)page->index)
+ extent_base = (((loff_t)page_index)
* (PAGE_CACHE_SIZE / crypt_stat->extent_size));
rc = ecryptfs_derive_iv(extent_iv, crypt_stat,
(extent_base + extent_offset));
@@ -447,14 +448,13 @@ static int ecryptfs_encrypt_extent(struct page *enc_extent_page,
(unsigned long long)(extent_base + extent_offset), rc);
goto out;
}
- rc = crypt_page_offset(crypt_stat, enc_extent_page, page,
+ rc = crypt_page_offset(crypt_stat, dst_page, src_page,
(extent_offset * crypt_stat->extent_size),
- crypt_stat->extent_size, extent_iv, ENCRYPT);
+ crypt_stat->extent_size, extent_iv, op);
if (rc < 0) {
- printk(KERN_ERR "%s: Error attempting to encrypt page with "
- "page->index = [%ld], extent_offset = [%ld]; "
- "rc = [%d]\n", __func__, page->index, extent_offset,
- rc);
+ printk(KERN_ERR "%s: Error attempting to crypt page with "
+ "page_index = [%ld], extent_offset = [%ld]; "
+ "rc = [%d]\n", __func__, page_index, extent_offset, rc);
goto out;
}
rc = 0;
@@ -503,8 +503,8 @@ int ecryptfs_encrypt_page(struct page *page)
for (extent_offset = 0;
extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size);
extent_offset++) {
- rc = ecryptfs_encrypt_extent(enc_extent_page, crypt_stat, page,
- extent_offset);
+ rc = crypt_extent(enc_extent_page, crypt_stat, page,
+ extent_offset, ENCRYPT);
if (rc) {
printk(KERN_ERR "%s: Error encrypting extent; "
"rc = [%d]\n", __func__, rc);
@@ -531,40 +531,6 @@ out:
return rc;
}
-static int ecryptfs_decrypt_extent(struct page *page,
- struct ecryptfs_crypt_stat *crypt_stat,
- struct page *enc_extent_page,
- unsigned long extent_offset)
-{
- loff_t extent_base;
- char extent_iv[ECRYPTFS_MAX_IV_BYTES];
- int rc;
-
- extent_base = (((loff_t)page->index)
- * (PAGE_CACHE_SIZE / crypt_stat->extent_size));
- rc = ecryptfs_derive_iv(extent_iv, crypt_stat,
- (extent_base + extent_offset));
- if (rc) {
- ecryptfs_printk(KERN_ERR, "Error attempting to derive IV for "
- "extent [0x%.16llx]; rc = [%d]\n",
- (unsigned long long)(extent_base + extent_offset), rc);
- goto out;
- }
- 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]; "
- "rc = [%d]\n", __func__, page->index, extent_offset,
- rc);
- goto out;
- }
- rc = 0;
-out:
- return rc;
-}
-
/**
* ecryptfs_decrypt_page
* @page: Page mapped from the eCryptfs inode for the file; data read
@@ -610,8 +576,8 @@ int ecryptfs_decrypt_page(struct page *page)
for (extent_offset = 0;
extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size);
extent_offset++) {
- rc = ecryptfs_decrypt_extent(page, crypt_stat, page,
- extent_offset);
+ rc = crypt_extent(page, crypt_stat, page,
+ extent_offset, DECRYPT);
if (rc) {
printk(KERN_ERR "%s: Error encrypting extent; "
"rc = [%d]\n", __func__, rc);