crypto: ccp - Check for caller result area before using it

For a hash operation, the caller doesn't have to supply a result area on every call so don't use it / update it if it hasn't been supplied. Signed-off-by: Tom Lendacky <[email protected]> Signed-off-by: Herbert Xu <[email protected]>
josf · Jan 15, 2014 · 393897c · 393897c
1 parent 77dc4a5
commit 393897c
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Showing 2 changed files with 8 additions and 3 deletions.
diff --git a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
@@ -43,7 +43,9 @@ static int ccp_aes_cmac_complete(struct crypto_async_request *async_req,
 	} else
 		rctx->buf_count = 0;
 
-	memcpy(req->result, rctx->iv, digest_size);
+	/* Update result area if supplied */
+	if (req->result)
+		memcpy(req->result, rctx->iv, digest_size);
 
 e_free:
 	sg_free_table(&rctx->data_sg);

diff --git a/drivers/crypto/ccp/ccp-crypto-sha.c b/drivers/crypto/ccp/ccp-crypto-sha.c
@@ -74,14 +74,15 @@ static int ccp_sha_finish_hmac(struct crypto_async_request *async_req)
 	struct ahash_request *req = ahash_request_cast(async_req);
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 	struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
 	struct scatterlist sg[2];
 	unsigned int block_size =
 		crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
 	unsigned int digest_size = crypto_ahash_digestsize(tfm);
 
 	sg_init_table(sg, ARRAY_SIZE(sg));
 	sg_set_buf(&sg[0], ctx->u.sha.opad, block_size);
-	sg_set_buf(&sg[1], req->result, digest_size);
+	sg_set_buf(&sg[1], rctx->ctx, digest_size);
 
 	return ccp_sync_hash(ctx->u.sha.hmac_tfm, req->result, sg,
 			     block_size + digest_size);
@@ -106,7 +107,9 @@ static int ccp_sha_complete(struct crypto_async_request *async_req, int ret)
 	} else
 		rctx->buf_count = 0;
 
-	memcpy(req->result, rctx->ctx, digest_size);
+	/* Update result area if supplied */
+	if (req->result)
+		memcpy(req->result, rctx->ctx, digest_size);
 
 	/* If we're doing an HMAC, we need to perform that on the final op */
 	if (rctx->final && ctx->u.sha.key_len)