crypto: chacha-generic - use crypto_xor_cpy()

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>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/chacha_generic.c b/crypto/chacha_generic.c
index 90ec0ec1b4f742e65d4692f212ac385b18f231c8..a7fae9b73ec4e647dbf174327074eb05e13d3410 100644 (file)
--- 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);
        }
 }