crypto: salsa20-generic - use crypto_xor_cpy()

In salsa20_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>

1 files changed, 4 insertions, 5 deletions

diff --git a/crypto/salsa20_generic.c b/crypto/salsa20_generic.c
index 00fce32ae17a..443fba09cbed 100644
--- a/crypto/salsa20_generic.c
+++ b/crypto/salsa20_generic.c
@@ -86,18 +86,17 @@ static void salsa20_docrypt(u32 *state, u8 *dst, const u8 *src,
 {
         __le32 stream[SALSA20_BLOCK_SIZE / sizeof(__le32)];
 
-        if (dst != src)
-                memcpy(dst, src, bytes);
-
         while (bytes >= SALSA20_BLOCK_SIZE) {
                 salsa20_block(state, stream);
-                crypto_xor(dst, (const u8 *)stream, SALSA20_BLOCK_SIZE);
+                crypto_xor_cpy(dst, src, (const u8 *)stream,
+                               SALSA20_BLOCK_SIZE);
                 bytes -= SALSA20_BLOCK_SIZE;
                 dst += SALSA20_BLOCK_SIZE;
+                src += SALSA20_BLOCK_SIZE;
         }
         if (bytes) {
                 salsa20_block(state, stream);
-                crypto_xor(dst, (const u8 *)stream, bytes);
+                crypto_xor_cpy(dst, src, (const u8 *)stream, bytes);
         }
 }