#include <asm/unaligned.h>
#include "ecryptfs_kernel.h"
-static int
-ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat,
- struct page *dst_page, int dst_offset,
- struct page *src_page, int src_offset, int size,
- unsigned char *iv);
-static int
-ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat,
- struct page *dst_page, int dst_offset,
- struct page *src_page, int src_offset, int size,
- unsigned char *iv);
+#define DECRYPT 0
+#define ENCRYPT 1
/**
* ecryptfs_to_hex
}
/**
- * 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
+ * @dst_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 *dst_sg,
+ struct scatterlist *src_sg, int size,
+ unsigned char *iv, int op)
{
struct ablkcipher_request *req = NULL;
struct extent_crypt_result ecr;
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);
+ ablkcipher_request_set_crypt(req, src_sg, dst_sg, size, iv);
+ rc = op == ENCRYPT ? crypto_ablkcipher_encrypt(req) :
+ crypto_ablkcipher_decrypt(req);
if (rc == -EINPROGRESS || rc == -EBUSY) {
struct extent_crypt_result *ecr = req->base.data;
}
/**
- * ecryptfs_lower_offset_for_extent
+ * lower_offset_for_page
*
* Convert an eCryptfs page index into a lower byte offset
*/
-static void ecryptfs_lower_offset_for_extent(loff_t *offset, loff_t extent_num,
- struct ecryptfs_crypt_stat *crypt_stat)
+static loff_t lower_offset_for_page(struct ecryptfs_crypt_stat *crypt_stat,
+ struct page *page)
{
- (*offset) = ecryptfs_lower_header_size(crypt_stat)
- + (crypt_stat->extent_size * extent_num);
+ return ecryptfs_lower_header_size(crypt_stat) +
+ (page->index << PAGE_CACHE_SHIFT);
}
/**
- * ecryptfs_encrypt_extent
- * @enc_extent_page: Allocated page into which to encrypt the data in
- * @page
+ * crypt_extent
* @crypt_stat: crypt_stat containing cryptographic context for the
* encryption operation
- * @page: Page containing plaintext data extent to encrypt
+ * @dst_page: The page to write the result into
+ * @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 ecryptfs_crypt_stat *crypt_stat,
+ struct page *dst_page,
+ 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];
+ struct scatterlist src_sg, dst_sg;
+ size_t extent_size = crypt_stat->extent_size;
int rc;
- extent_base = (((loff_t)page->index)
- * (PAGE_CACHE_SIZE / crypt_stat->extent_size));
+ extent_base = (((loff_t)page_index) * (PAGE_CACHE_SIZE / extent_size));
rc = ecryptfs_derive_iv(extent_iv, crypt_stat,
(extent_base + extent_offset));
if (rc) {
(unsigned long long)(extent_base + extent_offset), rc);
goto out;
}
- rc = ecryptfs_encrypt_page_offset(crypt_stat, enc_extent_page, 0,
- page, (extent_offset
- * crypt_stat->extent_size),
- crypt_stat->extent_size, extent_iv);
+
+ sg_init_table(&src_sg, 1);
+ sg_init_table(&dst_sg, 1);
+
+ sg_set_page(&src_sg, src_page, extent_size,
+ extent_offset * extent_size);
+ sg_set_page(&dst_sg, dst_page, extent_size,
+ extent_offset * extent_size);
+
+ rc = crypt_scatterlist(crypt_stat, &dst_sg, &src_sg, 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;
char *enc_extent_virt;
struct page *enc_extent_page = NULL;
loff_t extent_offset;
+ loff_t lower_offset;
int rc = 0;
ecryptfs_inode = page->mapping->host;
"encrypted extent\n");
goto out;
}
- enc_extent_virt = kmap(enc_extent_page);
+
for (extent_offset = 0;
extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size);
extent_offset++) {
- loff_t offset;
-
- rc = ecryptfs_encrypt_extent(enc_extent_page, crypt_stat, page,
- extent_offset);
+ rc = crypt_extent(crypt_stat, enc_extent_page, page,
+ extent_offset, ENCRYPT);
if (rc) {
printk(KERN_ERR "%s: Error encrypting extent; "
"rc = [%d]\n", __func__, rc);
goto out;
}
- ecryptfs_lower_offset_for_extent(
- &offset, ((((loff_t)page->index)
- * (PAGE_CACHE_SIZE
- / crypt_stat->extent_size))
- + extent_offset), crypt_stat);
- rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt,
- offset, crypt_stat->extent_size);
- if (rc < 0) {
- ecryptfs_printk(KERN_ERR, "Error attempting "
- "to write lower page; rc = [%d]"
- "\n", rc);
- goto out;
- }
- }
- rc = 0;
-out:
- if (enc_extent_page) {
- kunmap(enc_extent_page);
- __free_page(enc_extent_page);
}
- 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 = ecryptfs_decrypt_page_offset(crypt_stat, page,
- (extent_offset
- * crypt_stat->extent_size),
- enc_extent_page, 0,
- crypt_stat->extent_size, extent_iv);
+ lower_offset = lower_offset_for_page(crypt_stat, page);
+ enc_extent_virt = kmap(enc_extent_page);
+ rc = ecryptfs_write_lower(ecryptfs_inode, enc_extent_virt, lower_offset,
+ PAGE_CACHE_SIZE);
+ kunmap(enc_extent_page);
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);
+ ecryptfs_printk(KERN_ERR,
+ "Error attempting to write lower page; rc = [%d]\n",
+ rc);
goto out;
}
rc = 0;
out:
+ if (enc_extent_page) {
+ __free_page(enc_extent_page);
+ }
return rc;
}
{
struct inode *ecryptfs_inode;
struct ecryptfs_crypt_stat *crypt_stat;
- char *enc_extent_virt;
- struct page *enc_extent_page = NULL;
+ char *page_virt;
unsigned long extent_offset;
+ loff_t lower_offset;
int rc = 0;
ecryptfs_inode = page->mapping->host;
crypt_stat =
&(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat);
BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED));
- enc_extent_page = alloc_page(GFP_USER);
- if (!enc_extent_page) {
- rc = -ENOMEM;
- ecryptfs_printk(KERN_ERR, "Error allocating memory for "
- "encrypted extent\n");
+
+ lower_offset = lower_offset_for_page(crypt_stat, page);
+ page_virt = kmap(page);
+ rc = ecryptfs_read_lower(page_virt, lower_offset, PAGE_CACHE_SIZE,
+ ecryptfs_inode);
+ kunmap(page);
+ if (rc < 0) {
+ ecryptfs_printk(KERN_ERR,
+ "Error attempting to read lower page; rc = [%d]\n",
+ rc);
goto out;
}
- enc_extent_virt = kmap(enc_extent_page);
+
for (extent_offset = 0;
extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size);
extent_offset++) {
- loff_t offset;
-
- ecryptfs_lower_offset_for_extent(
- &offset, ((page->index * (PAGE_CACHE_SIZE
- / crypt_stat->extent_size))
- + extent_offset), crypt_stat);
- rc = ecryptfs_read_lower(enc_extent_virt, offset,
- crypt_stat->extent_size,
- ecryptfs_inode);
- if (rc < 0) {
- ecryptfs_printk(KERN_ERR, "Error attempting "
- "to read lower page; rc = [%d]"
- "\n", rc);
- goto out;
- }
- rc = ecryptfs_decrypt_extent(page, crypt_stat, enc_extent_page,
- extent_offset);
+ rc = crypt_extent(crypt_stat, page, page,
+ extent_offset, DECRYPT);
if (rc) {
printk(KERN_ERR "%s: Error encrypting extent; "
"rc = [%d]\n", __func__, rc);
}
}
out:
- if (enc_extent_page) {
- kunmap(enc_extent_page);
- __free_page(enc_extent_page);
- }
- return rc;
-}
-
-/**
- * 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
- * @dst_offset: The offset in the page to encrypt into
- * @src_page: The page to encrypt from
- * @src_offset: The offset in the page to encrypt from
- * @size: The number of bytes to encrypt
- * @iv: The initialization vector to use for the encryption
- *
- * Returns the number of bytes encrypted
- */
-static int
-ecryptfs_encrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat,
- struct page *dst_page, int dst_offset,
- struct page *src_page, int src_offset, int size,
- unsigned char *iv)
-{
- struct scatterlist src_sg, dst_sg;
-
- sg_init_table(&src_sg, 1);
- sg_init_table(&dst_sg, 1);
-
- sg_set_page(&src_sg, src_page, size, src_offset);
- sg_set_page(&dst_sg, dst_page, size, dst_offset);
- return encrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv);
-}
-
-/**
- * ecryptfs_decrypt_page_offset
- * @crypt_stat: The cryptographic context
- * @dst_page: The page to decrypt into
- * @dst_offset: The offset in the page to decrypt into
- * @src_page: The page to decrypt from
- * @src_offset: The offset in the page 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
- */
-static int
-ecryptfs_decrypt_page_offset(struct ecryptfs_crypt_stat *crypt_stat,
- struct page *dst_page, int dst_offset,
- struct page *src_page, int src_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, src_offset);
-
- sg_init_table(&dst_sg, 1);
- sg_set_page(&dst_sg, dst_page, size, dst_offset);
-
- return decrypt_scatterlist(crypt_stat, &dst_sg, &src_sg, size, iv);
}
#define ECRYPTFS_MAX_SCATTERLIST_LEN 4
projects / linux-2.6-block.git / blobdiff