[CRYPTO] blkcipher: Remove alignment restriction on block size

Previously we assumed for convenience that the block size is a multiple of
the algorithm's required alignment.  With the pending addition of CTR this
will no longer be the case as the block size will be 1 due to it being a
stream cipher.  However, the alignment requirement will be that of the
underlying implementation which will most likely be greater than 1.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 8 insertions, 5 deletions

diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c
index 9c49770837c2..a3c87da23f1e 100644
--- a/crypto/blkcipher.c
+++ b/crypto/blkcipher.c
@@ -149,6 +149,7 @@ static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
                                       unsigned int alignmask)
 {
         unsigned int n;
+        unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
 
         if (walk->buffer)
                 goto ok;
@@ -167,8 +168,8 @@ ok:
         walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,
                                           alignmask + 1);
         walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);
-        walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr + bsize,
-                                                 bsize);
+        walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr +
+                                                 aligned_bsize, bsize);
 
         scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
 
@@ -278,7 +279,9 @@ static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,
 {
         unsigned bs = crypto_blkcipher_blocksize(tfm);
         unsigned int ivsize = crypto_blkcipher_ivsize(tfm);
-        unsigned int size = bs * 2 + ivsize + max(bs, ivsize) - (alignmask + 1);
+        unsigned aligned_bs = ALIGN(bs, alignmask + 1);
+        unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
+                            (alignmask + 1);
         u8 *iv;
 
         size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
@@ -287,8 +290,8 @@ static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,
                 return -ENOMEM;
 
         iv = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
-        iv = blkcipher_get_spot(iv, bs) + bs;
-        iv = blkcipher_get_spot(iv, bs) + bs;
+        iv = blkcipher_get_spot(iv, bs) + aligned_bs;
+        iv = blkcipher_get_spot(iv, bs) + aligned_bs;
         iv = blkcipher_get_spot(iv, ivsize);
 
         walk->iv = memcpy(iv, walk->iv, ivsize);