[CRYPTO] authenc: Merge common hashing code

This patch merges the common hashing code between encryption and decryption.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/authenc.c

@@ -87,17 +87,18 @@ badkey:
 	goto out;
 }
 
-static int crypto_authenc_hash(struct aead_request *req)
+static u8 *crypto_authenc_hash(struct aead_request *req, unsigned int flags,
+			       struct scatterlist *cipher,
+			       unsigned int cryptlen)
 {
 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
 	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
 	struct crypto_hash *auth = ctx->auth;
 	struct hash_desc desc = {
 		.tfm = auth,
+		.flags = aead_request_flags(req) & flags,
 	};
 	u8 *hash = aead_request_ctx(req);
-	struct scatterlist *dst = req->dst;
-	unsigned int cryptlen = req->cryptlen;
 	int err;
 
 	hash = (u8 *)ALIGN((unsigned long)hash + crypto_hash_alignmask(auth), 
@@ -112,7 +113,7 @@ static int crypto_authenc_hash(struct aead_request *req)
 	if (err)
 		goto auth_unlock;
 
-	err = crypto_hash_update(&desc, dst, cryptlen);
+	err = crypto_hash_update(&desc, cipher, cryptlen);
 	if (err)
 		goto auth_unlock;
 
@@ -121,7 +122,21 @@ auth_unlock:
 	spin_unlock_bh(&ctx->auth_lock);
 
 	if (err)
-		return err;
+		return ERR_PTR(err);
+
+	return hash;
+}
+
+static int crypto_authenc_genicv(struct aead_request *req, unsigned int flags)
+{
+	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
+	struct scatterlist *dst = req->dst;
+	unsigned int cryptlen = req->cryptlen;
+	u8 *hash;
+
+	hash = crypto_authenc_hash(req, flags, dst, cryptlen);
+	if (IS_ERR(hash))
+		return PTR_ERR(hash);
 
 	scatterwalk_map_and_copy(hash, dst, cryptlen,
 				 crypto_aead_authsize(authenc), 1);
@@ -132,7 +147,7 @@ static void crypto_authenc_encrypt_done(struct crypto_async_request *req,
 					int err)
 {
 	if (!err)
-		err = crypto_authenc_hash(req->data);
+		err = crypto_authenc_genicv(req->data, 0);
 
 	aead_request_complete(req->data, err);
 }
@@ -154,50 +169,25 @@ static int crypto_authenc_encrypt(struct aead_request *req)
 	if (err)
 		return err;
 
-	return crypto_authenc_hash(req);
+	return crypto_authenc_genicv(req, CRYPTO_TFM_REQ_MAY_SLEEP);
 }
 
 static int crypto_authenc_verify(struct aead_request *req,
 				 unsigned int cryptlen)
 {
 	struct crypto_aead *authenc = crypto_aead_reqtfm(req);
-	struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc);
-	struct crypto_hash *auth = ctx->auth;
-	struct hash_desc desc = {
-		.tfm = auth,
-		.flags = aead_request_flags(req),
-	};
-	u8 *ohash = aead_request_ctx(req);
+	u8 *ohash;
 	u8 *ihash;
 	struct scatterlist *src = req->src;
 	unsigned int authsize;
-	int err;
 
-	ohash = (u8 *)ALIGN((unsigned long)ohash + crypto_hash_alignmask(auth), 
-			    crypto_hash_alignmask(auth) + 1);
-	ihash = ohash + crypto_hash_digestsize(auth);
-
-	spin_lock_bh(&ctx->auth_lock);
-	err = crypto_hash_init(&desc);
-	if (err)
-		goto auth_unlock;
-
-	err = crypto_hash_update(&desc, req->assoc, req->assoclen);
-	if (err)
-		goto auth_unlock;
-
-	err = crypto_hash_update(&desc, src, cryptlen);
-	if (err)
-		goto auth_unlock;
-
-	err = crypto_hash_final(&desc, ohash);
-auth_unlock:
-	spin_unlock_bh(&ctx->auth_lock);
-
-	if (err)
-		return err;
+	ohash = crypto_authenc_hash(req, CRYPTO_TFM_REQ_MAY_SLEEP, src,
+				    cryptlen);
+	if (IS_ERR(ohash))
+		return PTR_ERR(ohash);
 
 	authsize = crypto_aead_authsize(authenc);
+	ihash = ohash + authsize;
 	scatterwalk_map_and_copy(ihash, src, cryptlen, authsize, 0);
 	return memcmp(ihash, ohash, authsize) ? -EBADMSG: 0;
 }