[PATCH 13/22] crypto: cavium/cpt - add check for xts input length equal to zero

[Andrei Botila]

From: Andrei Botila <andrei.botila@xxxxxxx>

Standardize the way input lengths equal to 0 are handled in all skcipher
algorithms. All the algorithms return 0 for input lengths equal to zero.

Cc: George Cherian <gcherian@xxxxxxxxxxx>
Signed-off-by: Andrei Botila <andrei.botila@xxxxxxx>
---
 drivers/crypto/cavium/cpt/cptvf_algs.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/crypto/cavium/cpt/cptvf_algs.c b/drivers/crypto/cavium/cpt/cptvf_algs.c
index 5af0dc2a8909..edc18c8dd571 100644
--- a/drivers/crypto/cavium/cpt/cptvf_algs.c
+++ b/drivers/crypto/cavium/cpt/cptvf_algs.c
@@ -193,6 +193,7 @@ static inline void create_output_list(struct skcipher_request *req,
 static inline int cvm_enc_dec(struct skcipher_request *req, u32 enc)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	struct cvm_enc_ctx *ctx = crypto_skcipher_ctx(tfm);
 	struct cvm_req_ctx *rctx = skcipher_request_ctx(req);
 	u32 enc_iv_len = crypto_skcipher_ivsize(tfm);
 	struct fc_context *fctx = &rctx->fctx;
@@ -200,6 +201,9 @@ static inline int cvm_enc_dec(struct skcipher_request *req, u32 enc)
 	void *cdev = NULL;
 	int status;
 
+	if (!req->cryptlen && ctx->cipher_type == AES_XTS)
+		return 0;
+
 	memset(req_info, 0, sizeof(struct cpt_request_info));
 	req_info->may_sleep = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) != 0;
 	memset(fctx, 0, sizeof(struct fc_context));
-- 
2.17.1