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/* vi: set sw=4 ts=4: */
/*
* Based on shasum from http://www.netsw.org/crypto/hash/
* Majorly hacked up to use Dr Brian Gladman's sha1 code
*
* 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 tarball for details.
*
* ---------------------------------------------------------------------------
* Issue Date: 10/11/2002
*
* 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
*/
#include "libbb.h"
#define SHA1_BLOCK_SIZE 64
#define SHA1_DIGEST_SIZE 20
#define SHA1_HASH_SIZE SHA1_DIGEST_SIZE
#define SHA1_MASK (SHA1_BLOCK_SIZE - 1)
#define rotl32(x,n) (((x) << n) | ((x) >> (32 - n)))
/* Reverse byte order in 32-bit words */
#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. This version uses */
/* partial loop unrolling and is optimised for the Pentium 4 */
#define rnd(f,k) \
do { \
t = a; a = rotl32(a,5) + f(b,c,d) + e + k + w[i]; \
e = d; d = c; c = rotl32(b, 30); b = t; \
} while (0)
static void sha1_compile(sha1_ctx_t *ctx)
{
uint32_t w[80], i, a, b, c, d, e, t;
/* note that words are compiled from the buffer into 32-bit */
/* words in big-endian order so an order reversal is needed */
/* here on little endian machines */
for (i = 0; i < SHA1_BLOCK_SIZE / 4; ++i)
w[i] = htonl(ctx->wbuf[i]);
for (i = SHA1_BLOCK_SIZE / 4; i < 80; ++i)
w[i] = rotl32(w[i - 3] ^ w[i - 8] ^ w[i - 14] ^ w[i - 16], 1);
a = ctx->hash[0];
b = ctx->hash[1];
c = ctx->hash[2];
d = ctx->hash[3];
e = ctx->hash[4];
for (i = 0; i < 20; ++i)
rnd(ch, 0x5a827999);
for (i = 20; i < 40; ++i)
rnd(parity, 0x6ed9eba1);
for (i = 40; i < 60; ++i)
rnd(maj, 0x8f1bbcdc);
for (i = 60; i < 80; ++i)
rnd(parity, 0xca62c1d6);
ctx->hash[0] += a;
ctx->hash[1] += b;
ctx->hash[2] += c;
ctx->hash[3] += d;
ctx->hash[4] += e;
}
void FAST_FUNC sha1_begin(sha1_ctx_t *ctx)
{
ctx->count[0] = ctx->count[1] = 0;
ctx->hash[0] = 0x67452301;
ctx->hash[1] = 0xefcdab89;
ctx->hash[2] = 0x98badcfe;
ctx->hash[3] = 0x10325476;
ctx->hash[4] = 0xc3d2e1f0;
}
/* SHA1 hash data in an array of bytes into hash buffer and call the */
/* hash_compile function as required. */
void FAST_FUNC sha1_hash(const void *data, size_t length, sha1_ctx_t *ctx)
{
uint32_t pos = (uint32_t) (ctx->count[0] & SHA1_MASK);
uint32_t freeb = SHA1_BLOCK_SIZE - pos;
const unsigned char *sp = data;
if ((ctx->count[0] += length) < length)
ctx->count[1]++;
while (length >= freeb) { /* transfer whole blocks while possible */
memcpy(((unsigned char *) ctx->wbuf) + pos, sp, freeb);
sp += freeb;
length -= freeb;
freeb = SHA1_BLOCK_SIZE;
pos = 0;
sha1_compile(ctx);
}
memcpy(((unsigned char *) ctx->wbuf) + pos, sp, length);
}
void* FAST_FUNC sha1_end(void *resbuf, sha1_ctx_t *ctx)
{
/* SHA1 Final padding and digest calculation */
#if BB_BIG_ENDIAN
static const uint32_t mask[4] = { 0x00000000, 0xff000000, 0xffff0000, 0xffffff00 };
static const uint32_t bits[4] = { 0x80000000, 0x00800000, 0x00008000, 0x00000080 };
#else
static const uint32_t mask[4] = { 0x00000000, 0x000000ff, 0x0000ffff, 0x00ffffff };
static const uint32_t bits[4] = { 0x00000080, 0x00008000, 0x00800000, 0x80000000 };
#endif
uint8_t *hval = resbuf;
uint32_t i, cnt = (uint32_t) (ctx->count[0] & SHA1_MASK);
/* mask out the rest of any partial 32-bit word and then set */
/* the next byte to 0x80. On big-endian machines any bytes in */
/* the buffer will be at the top end of 32 bit words, on little */
/* endian machines they will be at the bottom. Hence the AND */
/* and OR masks above are reversed for little endian systems */
ctx->wbuf[cnt >> 2] =
(ctx->wbuf[cnt >> 2] & mask[cnt & 3]) | bits[cnt & 3];
/* we need 9 or more empty positions, one for the padding byte */
/* (above) and eight for the length count. If there is not */
/* enough space pad and empty the buffer */
if (cnt > SHA1_BLOCK_SIZE - 9) {
if (cnt < 60)
ctx->wbuf[15] = 0;
sha1_compile(ctx);
cnt = 0;
} else /* compute a word index for the empty buffer positions */
cnt = (cnt >> 2) + 1;
while (cnt < 14) /* and zero pad all but last two positions */
ctx->wbuf[cnt++] = 0;
/* assemble the eight byte counter in the buffer in big-endian */
/* format */
ctx->wbuf[14] = htonl((ctx->count[1] << 3) | (ctx->count[0] >> 29));
ctx->wbuf[15] = htonl(ctx->count[0] << 3);
sha1_compile(ctx);
/* extract the hash value as bytes in case the hash buffer is */
/* misaligned for 32-bit words */
for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
hval[i] = (unsigned char) (ctx->hash[i >> 2] >> 8 * (~i & 3));
return resbuf;
}
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