[CRYPTO] sha1: Avoid useless memcpy()
The current code unconditionally copy the first block for every call to
sha1_update(). This can be avoided if there is no pending partial block.
This is always the case on the first call to sha1_update() (if the length
is >= 64 of course.
Furthermore, temp does need to be called if sha_transform is never invoked.
Also consolidate the sha_transform calls into one to reduce code size.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/sha1.c b/crypto/sha1.c
index c686e78..292dcc1 100644
--- a/crypto/sha1.c
+++ b/crypto/sha1.c
@@ -50,22 +50,31 @@
{
struct sha1_ctx *sctx = ctx;
unsigned int i, j;
- u32 temp[SHA_WORKSPACE_WORDS];
+ const u8 *src;
j = (sctx->count >> 3) & 0x3f;
sctx->count += len << 3;
+ i = 0;
+ src = data;
if ((j + len) > 63) {
- memcpy(&sctx->buffer[j], data, (i = 64-j));
- sha_transform(sctx->state, sctx->buffer, temp);
- for ( ; i + 63 < len; i += 64) {
- sha_transform(sctx->state, &data[i], temp);
+ u32 temp[SHA_WORKSPACE_WORDS];
+
+ if (j) {
+ memcpy(&sctx->buffer[j], data, (i = 64-j));
+ src = sctx->buffer;
}
+
+ do {
+ sha_transform(sctx->state, src, temp);
+ i += 64;
+ src = &data[i];
+ } while (i + 63 < len);
+
+ memset(temp, 0, sizeof(temp));
j = 0;
}
- else i = 0;
- memset(temp, 0, sizeof(temp));
- memcpy(&sctx->buffer[j], &data[i], len - i);
+ memcpy(&sctx->buffer[j], src, len - i);
}
