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[CRYPTO] sha1: Avoid useless memcpy()

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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>
This commit is contained in:
Nicolas Pitre 2005-11-13 10:47:20 +11:00 committed by David S. Miller
parent c8a19c91b5
commit cfa8d17cc8
1 changed files with 17 additions and 8 deletions
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25
crypto/sha1.c
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@ -50,22 +50,31 @@ static void sha1_update(void *ctx, const u8 *data, unsigned int len)
{
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);
}