crypto: sahara - avoid skcipher fallback code duplication

[ Upstream commit 01d70a4bbff20ea05cadb4c208841985a7cc6596 ]

Factor out duplicated skcipher fallback handling code to a helper function
sahara_aes_fallback(). Also, keep a single check if fallback is required in
sahara_aes_crypt().

Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Stable-dep-of: d1d6351e37aa ("crypto: sahara - handle zero-length aes requests")
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/crypto/sahara.c

@@ -649,12 +649,37 @@ static int sahara_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
 	return crypto_skcipher_setkey(ctx->fallback, key, keylen);
 }
 
+static int sahara_aes_fallback(struct skcipher_request *req, unsigned long mode)
+{
+	struct sahara_aes_reqctx *rctx = skcipher_request_ctx(req);
+	struct sahara_ctx *ctx = crypto_skcipher_ctx(
+		crypto_skcipher_reqtfm(req));
+
+	skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback);
+	skcipher_request_set_callback(&rctx->fallback_req,
+				      req->base.flags,
+				      req->base.complete,
+				      req->base.data);
+	skcipher_request_set_crypt(&rctx->fallback_req, req->src,
+				   req->dst, req->cryptlen, req->iv);
+
+	if (mode & FLAGS_ENCRYPT)
+		return crypto_skcipher_encrypt(&rctx->fallback_req);
+
+	return crypto_skcipher_decrypt(&rctx->fallback_req);
+}
+
 static int sahara_aes_crypt(struct skcipher_request *req, unsigned long mode)
 {
 	struct sahara_aes_reqctx *rctx = skcipher_request_ctx(req);
+	struct sahara_ctx *ctx = crypto_skcipher_ctx(
+		crypto_skcipher_reqtfm(req));
 	struct sahara_dev *dev = dev_ptr;
 	int err = 0;
 
+	if (unlikely(ctx->keylen != AES_KEYSIZE_128))
+		return sahara_aes_fallback(req, mode);
+
 	dev_dbg(dev->device, "nbytes: %d, enc: %d, cbc: %d\n",
 		req->cryptlen, !!(mode & FLAGS_ENCRYPT), !!(mode & FLAGS_CBC));
 
@@ -677,81 +702,21 @@ static int sahara_aes_crypt(struct skcipher_request *req, unsigned long mode)
 
 static int sahara_aes_ecb_encrypt(struct skcipher_request *req)
 {
-	struct sahara_aes_reqctx *rctx = skcipher_request_ctx(req);
-	struct sahara_ctx *ctx = crypto_skcipher_ctx(
-		crypto_skcipher_reqtfm(req));
-
-	if (unlikely(ctx->keylen != AES_KEYSIZE_128)) {
-		skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback);
-		skcipher_request_set_callback(&rctx->fallback_req,
-					      req->base.flags,
-					      req->base.complete,
-					      req->base.data);
-		skcipher_request_set_crypt(&rctx->fallback_req, req->src,
-					   req->dst, req->cryptlen, req->iv);
-		return crypto_skcipher_encrypt(&rctx->fallback_req);
-	}
-
 	return sahara_aes_crypt(req, FLAGS_ENCRYPT);
 }
 
 static int sahara_aes_ecb_decrypt(struct skcipher_request *req)
 {
-	struct sahara_aes_reqctx *rctx = skcipher_request_ctx(req);
-	struct sahara_ctx *ctx = crypto_skcipher_ctx(
-		crypto_skcipher_reqtfm(req));
-
-	if (unlikely(ctx->keylen != AES_KEYSIZE_128)) {
-		skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback);
-		skcipher_request_set_callback(&rctx->fallback_req,
-					      req->base.flags,
-					      req->base.complete,
-					      req->base.data);
-		skcipher_request_set_crypt(&rctx->fallback_req, req->src,
-					   req->dst, req->cryptlen, req->iv);
-		return crypto_skcipher_decrypt(&rctx->fallback_req);
-	}
-
 	return sahara_aes_crypt(req, 0);
 }
 
 static int sahara_aes_cbc_encrypt(struct skcipher_request *req)
 {
-	struct sahara_aes_reqctx *rctx = skcipher_request_ctx(req);
-	struct sahara_ctx *ctx = crypto_skcipher_ctx(
-		crypto_skcipher_reqtfm(req));
-
-	if (unlikely(ctx->keylen != AES_KEYSIZE_128)) {
-		skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback);
-		skcipher_request_set_callback(&rctx->fallback_req,
-					      req->base.flags,
-					      req->base.complete,
-					      req->base.data);
-		skcipher_request_set_crypt(&rctx->fallback_req, req->src,
-					   req->dst, req->cryptlen, req->iv);
-		return crypto_skcipher_encrypt(&rctx->fallback_req);
-	}
-
 	return sahara_aes_crypt(req, FLAGS_ENCRYPT | FLAGS_CBC);
 }
 
 static int sahara_aes_cbc_decrypt(struct skcipher_request *req)
 {
-	struct sahara_aes_reqctx *rctx = skcipher_request_ctx(req);
-	struct sahara_ctx *ctx = crypto_skcipher_ctx(
-		crypto_skcipher_reqtfm(req));
-
-	if (unlikely(ctx->keylen != AES_KEYSIZE_128)) {
-		skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback);
-		skcipher_request_set_callback(&rctx->fallback_req,
-					      req->base.flags,
-					      req->base.complete,
-					      req->base.data);
-		skcipher_request_set_crypt(&rctx->fallback_req, req->src,
-					   req->dst, req->cryptlen, req->iv);
-		return crypto_skcipher_decrypt(&rctx->fallback_req);
-	}
-
 	return sahara_aes_crypt(req, FLAGS_CBC);
 }