[PATCH] crypto: chacha-generic - use crypto_xor_cpy()

[PATCH] crypto: chacha-generic - use crypto_xor_cpy()

[Eric Biggers]

From: Eric Biggers <ebiggers@google.com>

In chacha_docrypt(), use crypto_xor_cpy() instead of crypto_xor().
This avoids having to memcpy() the src buffer to the dst buffer.

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 crypto/chacha_generic.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/crypto/chacha_generic.c b/crypto/chacha_generic.c
index 90ec0ec1b4f7..a7fae9b73ec4 100644
--- a/crypto/chacha_generic.c
+++ b/crypto/chacha_generic.c
@@ -22,18 +22,16 @@ static void chacha_docrypt(u32 *state, u8 *dst, const u8 *src,
 	/* aligned to potentially speed up crypto_xor() */
 	u8 stream[CHACHA_BLOCK_SIZE] __aligned(sizeof(long));
 
-	if (dst != src)
-		memcpy(dst, src, bytes);
-
 	while (bytes >= CHACHA_BLOCK_SIZE) {
 		chacha_block(state, stream, nrounds);
-		crypto_xor(dst, stream, CHACHA_BLOCK_SIZE);
+		crypto_xor_cpy(dst, src, stream, CHACHA_BLOCK_SIZE);
 		bytes -= CHACHA_BLOCK_SIZE;
 		dst += CHACHA_BLOCK_SIZE;
+		src += CHACHA_BLOCK_SIZE;
 	}
 	if (bytes) {
 		chacha_block(state, stream, nrounds);
-		crypto_xor(dst, stream, bytes);
+		crypto_xor_cpy(dst, src, stream, bytes);
 	}
 }
 
-- 
2.21.0

Re: [PATCH] crypto: chacha-generic - use crypto_xor_cpy()

[Herbert Xu]

On Thu, Mar 14, 2019 at 09:20:36PM -0700, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> In chacha_docrypt(), use crypto_xor_cpy() instead of crypto_xor().
> This avoids having to memcpy() the src buffer to the dst buffer.
> 
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> ---
>  crypto/chacha_generic.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt