[BLOCK] cryptoloop: Use block ciphers where applicable
This patch converts cryptoloop to use the new block cipher type where
applicable. As a result the ECB-specific and CBC-specific transfer
functions have been merged.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/block/cryptoloop.c b/drivers/block/cryptoloop.c
index 3d4261c..4053503 100644
--- a/drivers/block/cryptoloop.c
+++ b/drivers/block/cryptoloop.c
@@ -40,11 +40,13 @@
cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info)
{
int err = -EINVAL;
+ int cipher_len;
+ int mode_len;
char cms[LO_NAME_SIZE]; /* cipher-mode string */
char *cipher;
char *mode;
char *cmsp = cms; /* c-m string pointer */
- struct crypto_tfm *tfm = NULL;
+ struct crypto_blkcipher *tfm;
/* encryption breaks for non sector aligned offsets */
@@ -53,20 +55,39 @@
strncpy(cms, info->lo_crypt_name, LO_NAME_SIZE);
cms[LO_NAME_SIZE - 1] = 0;
- cipher = strsep(&cmsp, "-");
- mode = strsep(&cmsp, "-");
- if (mode == NULL || strcmp(mode, "cbc") == 0)
- tfm = crypto_alloc_tfm(cipher, CRYPTO_TFM_MODE_CBC |
- CRYPTO_TFM_REQ_MAY_SLEEP);
- else if (strcmp(mode, "ecb") == 0)
- tfm = crypto_alloc_tfm(cipher, CRYPTO_TFM_MODE_ECB |
- CRYPTO_TFM_REQ_MAY_SLEEP);
- if (tfm == NULL)
+ cipher = cmsp;
+ cipher_len = strcspn(cmsp, "-");
+
+ mode = cmsp + cipher_len;
+ mode_len = 0;
+ if (*mode) {
+ mode++;
+ mode_len = strcspn(mode, "-");
+ }
+
+ if (!mode_len) {
+ mode = "cbc";
+ mode_len = 3;
+ }
+
+ if (cipher_len + mode_len + 3 > LO_NAME_SIZE)
return -EINVAL;
- err = tfm->crt_u.cipher.cit_setkey(tfm, info->lo_encrypt_key,
- info->lo_encrypt_key_size);
+ memmove(cms, mode, mode_len);
+ cmsp = cms + mode_len;
+ *cmsp++ = '(';
+ memcpy(cmsp, info->lo_crypt_name, cipher_len);
+ cmsp += cipher_len;
+ *cmsp++ = ')';
+ *cmsp = 0;
+
+ tfm = crypto_alloc_blkcipher(cms, 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(tfm))
+ return PTR_ERR(tfm);
+
+ err = crypto_blkcipher_setkey(tfm, info->lo_encrypt_key,
+ info->lo_encrypt_key_size);
if (err != 0)
goto out_free_tfm;
@@ -75,99 +96,49 @@
return 0;
out_free_tfm:
- crypto_free_tfm(tfm);
+ crypto_free_blkcipher(tfm);
out:
return err;
}
-typedef int (*encdec_ecb_t)(struct crypto_tfm *tfm,
+typedef int (*encdec_cbc_t)(struct blkcipher_desc *desc,
struct scatterlist *sg_out,
struct scatterlist *sg_in,
unsigned int nsg);
-
static int
-cryptoloop_transfer_ecb(struct loop_device *lo, int cmd,
- struct page *raw_page, unsigned raw_off,
- struct page *loop_page, unsigned loop_off,
- int size, sector_t IV)
+cryptoloop_transfer(struct loop_device *lo, int cmd,
+ struct page *raw_page, unsigned raw_off,
+ struct page *loop_page, unsigned loop_off,
+ int size, sector_t IV)
{
- struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data;
- struct scatterlist sg_out = { NULL, };
- struct scatterlist sg_in = { NULL, };
-
- encdec_ecb_t encdecfunc;
- struct page *in_page, *out_page;
- unsigned in_offs, out_offs;
-
- if (cmd == READ) {
- in_page = raw_page;
- in_offs = raw_off;
- out_page = loop_page;
- out_offs = loop_off;
- encdecfunc = tfm->crt_u.cipher.cit_decrypt;
- } else {
- in_page = loop_page;
- in_offs = loop_off;
- out_page = raw_page;
- out_offs = raw_off;
- encdecfunc = tfm->crt_u.cipher.cit_encrypt;
- }
-
- while (size > 0) {
- const int sz = min(size, LOOP_IV_SECTOR_SIZE);
-
- sg_in.page = in_page;
- sg_in.offset = in_offs;
- sg_in.length = sz;
-
- sg_out.page = out_page;
- sg_out.offset = out_offs;
- sg_out.length = sz;
-
- encdecfunc(tfm, &sg_out, &sg_in, sz);
-
- size -= sz;
- in_offs += sz;
- out_offs += sz;
- }
-
- return 0;
-}
-
-typedef int (*encdec_cbc_t)(struct crypto_tfm *tfm,
- struct scatterlist *sg_out,
- struct scatterlist *sg_in,
- unsigned int nsg, u8 *iv);
-
-static int
-cryptoloop_transfer_cbc(struct loop_device *lo, int cmd,
- struct page *raw_page, unsigned raw_off,
- struct page *loop_page, unsigned loop_off,
- int size, sector_t IV)
-{
- struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data;
+ struct crypto_blkcipher *tfm = lo->key_data;
+ struct blkcipher_desc desc = {
+ .tfm = tfm,
+ .flags = CRYPTO_TFM_REQ_MAY_SLEEP,
+ };
struct scatterlist sg_out = { NULL, };
struct scatterlist sg_in = { NULL, };
encdec_cbc_t encdecfunc;
struct page *in_page, *out_page;
unsigned in_offs, out_offs;
+ int err;
if (cmd == READ) {
in_page = raw_page;
in_offs = raw_off;
out_page = loop_page;
out_offs = loop_off;
- encdecfunc = tfm->crt_u.cipher.cit_decrypt_iv;
+ encdecfunc = crypto_blkcipher_crt(tfm)->decrypt;
} else {
in_page = loop_page;
in_offs = loop_off;
out_page = raw_page;
out_offs = raw_off;
- encdecfunc = tfm->crt_u.cipher.cit_encrypt_iv;
+ encdecfunc = crypto_blkcipher_crt(tfm)->encrypt;
}
while (size > 0) {
@@ -183,7 +154,10 @@
sg_out.offset = out_offs;
sg_out.length = sz;
- encdecfunc(tfm, &sg_out, &sg_in, sz, (u8 *)iv);
+ desc.info = iv;
+ err = encdecfunc(&desc, &sg_out, &sg_in, sz);
+ if (err)
+ return err;
IV++;
size -= sz;
@@ -195,32 +169,6 @@
}
static int
-cryptoloop_transfer(struct loop_device *lo, int cmd,
- struct page *raw_page, unsigned raw_off,
- struct page *loop_page, unsigned loop_off,
- int size, sector_t IV)
-{
- struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data;
- if(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB)
- {
- lo->transfer = cryptoloop_transfer_ecb;
- return cryptoloop_transfer_ecb(lo, cmd, raw_page, raw_off,
- loop_page, loop_off, size, IV);
- }
- if(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_CBC)
- {
- lo->transfer = cryptoloop_transfer_cbc;
- return cryptoloop_transfer_cbc(lo, cmd, raw_page, raw_off,
- loop_page, loop_off, size, IV);
- }
-
- /* This is not supposed to happen */
-
- printk( KERN_ERR "cryptoloop: unsupported cipher mode in cryptoloop_transfer!\n");
- return -EINVAL;
-}
-
-static int
cryptoloop_ioctl(struct loop_device *lo, int cmd, unsigned long arg)
{
return -EINVAL;
@@ -229,9 +177,9 @@
static int
cryptoloop_release(struct loop_device *lo)
{
- struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data;
+ struct crypto_blkcipher *tfm = lo->key_data;
if (tfm != NULL) {
- crypto_free_tfm(tfm);
+ crypto_free_blkcipher(tfm);
lo->key_data = NULL;
return 0;
}