[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 3d4261c39f16d2542b9dc22c1cc077ed8bc07c1f..40535036e8936140c44ad8079526c0aed7ecbf68 100644 (file)
--- a/drivers/block/cryptoloop.c
+++ b/drivers/block/cryptoloop.c
@@ -40,11 +40,13 @@ static int
 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 @@ cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info)
 
        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 @@ cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info)
        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)
-{
-       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)
+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 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 @@ cryptoloop_transfer_cbc(struct loop_device *lo, int cmd,
                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;
@@ -194,32 +168,6 @@ cryptoloop_transfer_cbc(struct loop_device *lo, int cmd,
        return 0;
 }
 
-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)
 {
@@ -229,9 +177,9 @@ cryptoloop_ioctl(struct loop_device *lo, int cmd, unsigned long arg)
 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;
        }