From: Herbert Xu Subject: [PATCH 5/10] crypto: sha256_generic - Use 64-bit counter like sha1 Date: Sat, 11 Jul 2009 18:23:09 +0800 Message-ID: References: <20090711101958.GA14642@gondor.apana.org.au> To: Linux Crypto Mailing List Return-path: Received: from rhun.apana.org.au ([64.62.148.172]:54384 "EHLO arnor.apana.org.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754053AbZGKKXL (ORCPT ); Sat, 11 Jul 2009 06:23:11 -0400 Received: from gondolin.me.apana.org.au ([192.168.0.6]) by arnor.apana.org.au with esmtp (Exim 4.63 #1 (Debian)) id 1MPZja-00064i-9f for ; Sat, 11 Jul 2009 20:23:10 +1000 Sender: linux-crypto-owner@vger.kernel.org List-ID: crypto: sha256_generic - Use 64-bit counter like sha1 This patch replaces the two 32-bit counter code in sha256_generic with the simpler 64-bit counter code from sha1. Signed-off-by: Herbert Xu --- crypto/sha256_generic.c | 65 ++++++++++++++++++++++-------------------------- 1 file changed, 30 insertions(+), 35 deletions(-) diff --git a/crypto/sha256_generic.c b/crypto/sha256_generic.c index 6349d83..e58c71b 100644 --- a/crypto/sha256_generic.c +++ b/crypto/sha256_generic.c @@ -26,7 +26,7 @@ #include struct sha256_ctx { - u32 count[2]; + u64 count; u32 state[8]; u8 buf[128]; }; @@ -231,8 +231,7 @@ static int sha224_init(struct shash_desc *desc) sctx->state[5] = SHA224_H5; sctx->state[6] = SHA224_H6; sctx->state[7] = SHA224_H7; - sctx->count[0] = 0; - sctx->count[1] = 0; + sctx->count = 0; return 0; } @@ -248,7 +247,7 @@ static int sha256_init(struct shash_desc *desc) sctx->state[5] = SHA256_H5; sctx->state[6] = SHA256_H6; sctx->state[7] = SHA256_H7; - sctx->count[0] = sctx->count[1] = 0; + sctx->count = 0; return 0; } @@ -257,33 +256,30 @@ static int sha256_update(struct shash_desc *desc, const u8 *data, unsigned int len) { struct sha256_ctx *sctx = shash_desc_ctx(desc); - unsigned int i, index, part_len; - - /* Compute number of bytes mod 128 */ - index = (unsigned int)((sctx->count[0] >> 3) & 0x3f); - - /* Update number of bits */ - if ((sctx->count[0] += (len << 3)) < (len << 3)) { - sctx->count[1]++; - sctx->count[1] += (len >> 29); + unsigned int partial, done; + const u8 *src; + + partial = sctx->count & 0x3f; + sctx->count += len; + done = 0; + src = data; + + if ((partial + len) > 63) { + if (partial) { + done = -partial; + memcpy(sctx->buf + partial, data, done + 64); + src = sctx->buf; + } + + do { + sha256_transform(sctx->state, src); + done += 64; + src = data + done; + } while (done + 63 < len); + + partial = 0; } - - part_len = 64 - index; - - /* Transform as many times as possible. */ - if (len >= part_len) { - memcpy(&sctx->buf[index], data, part_len); - sha256_transform(sctx->state, sctx->buf); - - for (i = part_len; i + 63 < len; i += 64) - sha256_transform(sctx->state, &data[i]); - index = 0; - } else { - i = 0; - } - - /* Buffer remaining input */ - memcpy(&sctx->buf[index], &data[i], len-i); + memcpy(sctx->buf + partial, src, len - done); return 0; } @@ -292,22 +288,21 @@ static int sha256_final(struct shash_desc *desc, u8 *out) { struct sha256_ctx *sctx = shash_desc_ctx(desc); __be32 *dst = (__be32 *)out; - __be32 bits[2]; + __be64 bits; unsigned int index, pad_len; int i; static const u8 padding[64] = { 0x80, }; /* Save number of bits */ - bits[1] = cpu_to_be32(sctx->count[0]); - bits[0] = cpu_to_be32(sctx->count[1]); + bits = cpu_to_be64(sctx->count << 3); /* Pad out to 56 mod 64. */ - index = (sctx->count[0] >> 3) & 0x3f; + index = sctx->count & 0x3f; pad_len = (index < 56) ? (56 - index) : ((64+56) - index); sha256_update(desc, padding, pad_len); /* Append length (before padding) */ - sha256_update(desc, (const u8 *)bits, sizeof(bits)); + sha256_update(desc, (const u8 *)&bits, sizeof(bits)); /* Store state in digest */ for (i = 0; i < 8; i++)