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Subject[PATCH v2] crypto: sha1: modify sha1_update to use SHA1_BLOCK_SIZE
David Miller (davem@davemloft.net) wrote:
>
> The temp[] buffer is explicitly places inside the inner most
> basic block so that the compiler doesn't allocate the stack
> space unless that code path is taken.
>

Fixed in V2 (this patch). Thanks for the review.

-- >8 -- (snip)

Plus some other minor cleanup.

Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: Joe Perches <joe@perches.com>
Cc: linux-crypto@vger.kernel.org
---
crypto/sha1_generic.c | 33 +++++++++++++++------------------
1 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/crypto/sha1_generic.c b/crypto/sha1_generic.c
index 0416091..0b56719 100644
--- a/crypto/sha1_generic.c
+++ b/crypto/sha1_generic.c
@@ -40,33 +40,30 @@ static int sha1_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
struct sha1_state *sctx = shash_desc_ctx(desc);
- unsigned int partial, done;
- const u8 *src;
+ unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;

- partial = sctx->count & 0x3f;
sctx->count += len;
- done = 0;
- src = data;

- if ((partial + len) > 63) {
+ if ((partial + len) >= SHA1_BLOCK_SIZE) {
u32 temp[SHA_WORKSPACE_WORDS];

if (partial) {
- done = -partial;
- memcpy(sctx->buffer + partial, data, done + 64);
- src = sctx->buffer;
- }
-
- do {
- sha_transform(sctx->state, src, temp);
- done += 64;
- src = data + done;
- } while (done + 63 < len);
+ unsigned int done = SHA1_BLOCK_SIZE - partial;

+ memcpy(sctx->buffer + partial, data, done);
+ sha_transform(sctx->state, sctx->buffer, temp);
+ len -= done;
+ data += done;
+ partial = 0;
+ }
+ while (len >= SHA1_BLOCK_SIZE) {
+ sha_transform(sctx->state, data, temp);
+ len -= SHA1_BLOCK_SIZE;
+ data += SHA1_BLOCK_SIZE;
+ }
memset(temp, 0, sizeof(temp));
- partial = 0;
}
- memcpy(sctx->buffer + partial, src, len - done);
+ memcpy(sctx->buffer + partial, data, len);

return 0;
}
--
1.7.3.1


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