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authorDenys Vlasenko <vda.linux@googlemail.com>2010-10-24 17:27:30 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2010-10-24 17:27:30 (GMT)
commitf4c93ab30460667cb3506a89a5419508a7bcfa0e (patch)
treea2d3bcf0b1b303fd38faea68a0147e07f02b51a3
parent4b63e16d20f2c89b39e26a10cb1cdbcbf079df89 (diff)
downloadbusybox-f4c93ab30460667cb3506a89a5419508a7bcfa0e.tar.gz
busybox-f4c93ab30460667cb3506a89a5419508a7bcfa0e.tar.bz2
sha1: use Rob's code, it's smaller and faster
function old new delta static.rconsts - 16 +16 sha1_process_block64 460 298 -162 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 0/1 up/down: 16/-162) Total: -146 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--libbb/hash_md5_sha.c105
1 files changed, 51 insertions, 54 deletions
diff --git a/libbb/hash_md5_sha.c b/libbb/hash_md5_sha.c
index aeacdde..5e4078a 100644
--- a/libbb/hash_md5_sha.c
+++ b/libbb/hash_md5_sha.c
@@ -473,20 +473,13 @@ void FAST_FUNC md5_end(md5_ctx_t *ctx, void *resbuf)
/*
- * Based on shasum from http://www.netsw.org/crypto/hash/
- * Majorly hacked up to use Dr Brian Gladman's sha1 code
+ * SHA1 part is:
+ * Copyright 2007 Rob Landley <rob@landley.net>
*
- * Copyright (C) 2002 Dr Brian Gladman <brg@gladman.me.uk>, Worcester, UK.
- * Copyright (C) 2003 Glenn L. McGrath
- * Copyright (C) 2003 Erik Andersen
- *
- * Licensed under GPLv2 or later, see file LICENSE in this source tree.
- *
- * ---------------------------------------------------------------------------
- * Issue Date: 10/11/2002
+ * Based on the public domain SHA-1 in C by Steve Reid <steve@edmweb.com>
+ * from http://www.mirrors.wiretapped.net/security/cryptography/hashes/sha1/
*
- * This is a byte oriented version of SHA1 that operates on arrays of bytes
- * stored in memory. It runs at 22 cycles per byte on a Pentium P4 processor
+ * Licensed under GPLv2, see file LICENSE in this source tree.
*
* ---------------------------------------------------------------------------
*
@@ -503,16 +496,18 @@ void FAST_FUNC md5_end(md5_ctx_t *ctx, void *resbuf)
static void FAST_FUNC sha1_process_block64(sha1_ctx_t *ctx)
{
- unsigned t;
- uint32_t W[80], a, b, c, d, e;
- const uint32_t *words = (uint32_t*) ctx->wbuffer;
+ static const uint32_t rconsts[] = {
+ 0x5A827999, 0x6ED9EBA1, 0x8F1BBCDC, 0xCA62C1D6
+ };
+ int i, j;
+ int cnt;
+ uint32_t W[16+16];
+ uint32_t a, b, c, d, e;
- for (t = 0; t < 16; ++t)
- W[t] = SWAP_BE32(words[t]);
- for (/*t = 16*/; t < 80; ++t) {
- uint32_t T = W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16];
- W[t] = rotl32(T, 1);
- }
+ /* On-stack work buffer frees up one register in the main loop
+ * which otherwise will be needed to hold ctx pointer */
+ for (i = 0; i < 16; i++)
+ W[i] = W[i+16] = SWAP_BE32(((uint32_t*)ctx->wbuffer)[i]);
a = ctx->hash[0];
b = ctx->hash[1];
@@ -520,39 +515,41 @@ static void FAST_FUNC sha1_process_block64(sha1_ctx_t *ctx)
d = ctx->hash[3];
e = ctx->hash[4];
-#undef ch
-#undef parity
-#undef maj
-#undef rnd
-#define ch(x,y,z) ((z) ^ ((x) & ((y) ^ (z))))
-#define parity(x,y,z) ((x) ^ (y) ^ (z))
-#define maj(x,y,z) (((x) & (y)) | ((z) & ((x) | (y))))
-/* A normal version as set out in the FIPS. */
-#define rnd(f,k) \
- do { \
- uint32_t T = a; \
- a = rotl32(a, 5) + f(b, c, d) + e + k + W[t]; \
- e = d; \
- d = c; \
- c = rotl32(b, 30); \
- b = T; \
- } while (0)
-
- for (t = 0; t < 20; ++t)
- rnd(ch, 0x5a827999);
-
- for (/*t = 20*/; t < 40; ++t)
- rnd(parity, 0x6ed9eba1);
-
- for (/*t = 40*/; t < 60; ++t)
- rnd(maj, 0x8f1bbcdc);
-
- for (/*t = 60*/; t < 80; ++t)
- rnd(parity, 0xca62c1d6);
-#undef ch
-#undef parity
-#undef maj
-#undef rnd
+ /* 4 rounds of 20 operations each */
+ cnt = 0;
+ for (i = 0; i < 4; i++) {
+ j = 19;
+ do {
+ uint32_t work;
+
+ work = c ^ d;
+ if (i == 0) {
+ work = (work & b) ^ d;
+ if (j <= 3)
+ goto ge16;
+ /* Used to do SWAP_BE32 here, but this
+ * requires ctx (see comment above) */
+ work += W[cnt];
+ } else {
+ if (i == 2)
+ work = ((b | c) & d) | (b & c);
+ else /* i = 1 or 3 */
+ work ^= b;
+ ge16:
+ W[cnt] = W[cnt+16] = rotl32(W[cnt+13] ^ W[cnt+8] ^ W[cnt+2] ^ W[cnt], 1);
+ work += W[cnt];
+ }
+ work = e + work + rotl32(a, 5) + rconsts[i];
+
+ /* Rotate by one for next time */
+ e = d;
+ d = c;
+ c = /* b = */ rotl32(b, 30);
+ b = a;
+ a = work;
+ cnt = (cnt + 1) & 15;
+ } while (--j >= 0);
+ }
ctx->hash[0] += a;
ctx->hash[1] += b;