crypto: morus - fix handling chunked inputs

The generic MORUS implementations all fail the improved AEAD tests because they produce the wrong result with some data layouts. The issue is that they assume that if the skcipher_walk API gives 'nbytes' not aligned to the walksize (a.k.a. walk.stride), then it is the end of the data. In fact, this can happen before the end. Fix them. Fixes: 396be41 ("crypto: morus - Add generic MORUS AEAD implementations") Cc: <[email protected]> # v4.18+ Cc: Ondrej Mosnacek <[email protected]> Signed-off-by: Eric Biggers <[email protected]> Reviewed-by: Ondrej Mosnacek <[email protected]> Signed-off-by: Herbert Xu <[email protected]>
fracktal · Feb 8, 2019 · d644f1c · d644f1c
1 parent 0f533e6
commit d644f1c
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Showing 2 changed files with 14 additions and 12 deletions.
diff --git a/crypto/morus1280.c b/crypto/morus1280.c
@@ -362,18 +362,19 @@ static void crypto_morus1280_process_crypt(struct morus1280_state *state,
 					   const struct morus1280_ops *ops)
 {
 	struct skcipher_walk walk;
-	u8 *dst;
-	const u8 *src;
 
 	ops->skcipher_walk_init(&walk, req, false);
 
 	while (walk.nbytes) {
-		src = walk.src.virt.addr;
-		dst = walk.dst.virt.addr;
+		unsigned int nbytes = walk.nbytes;
 
-		ops->crypt_chunk(state, dst, src, walk.nbytes);
+		if (nbytes < walk.total)
+			nbytes = round_down(nbytes, walk.stride);
 
-		skcipher_walk_done(&walk, 0);
+		ops->crypt_chunk(state, walk.dst.virt.addr, walk.src.virt.addr,
+				 nbytes);
+
+		skcipher_walk_done(&walk, walk.nbytes - nbytes);
 	}
 }
 

diff --git a/crypto/morus640.c b/crypto/morus640.c
@@ -361,18 +361,19 @@ static void crypto_morus640_process_crypt(struct morus640_state *state,
 					  const struct morus640_ops *ops)
 {
 	struct skcipher_walk walk;
-	u8 *dst;
-	const u8 *src;
 
 	ops->skcipher_walk_init(&walk, req, false);
 
 	while (walk.nbytes) {
-		src = walk.src.virt.addr;
-		dst = walk.dst.virt.addr;
+		unsigned int nbytes = walk.nbytes;
 
-		ops->crypt_chunk(state, dst, src, walk.nbytes);
+		if (nbytes < walk.total)
+			nbytes = round_down(nbytes, walk.stride);
 
-		skcipher_walk_done(&walk, 0);
+		ops->crypt_chunk(state, walk.dst.virt.addr, walk.src.virt.addr,
+				 nbytes);
+
+		skcipher_walk_done(&walk, walk.nbytes - nbytes);
 	}
 }