/*
** Copyright (C) 2003 Meder Kydyraliev <meder@areopag.net>
** Copyright (C) 2001 Fyodor Yarochkin <fygrave@tigerteam.net>,
**                    Ofir Arkin       <ofir@sys-security.com>
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/

/*	$OpenBSD: sha1.c,v 1.10 2002/12/23 04:33:31 millert Exp $	*/

/*
 * SHA-1 in C
 * By Steve Reid <steve@edmweb.com>
 * 100% Public Domain
 *
 * Test Vectors (from FIPS PUB 180-1)
 * "abc"
 *   A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D
 * "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"
 *   84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1
 * A million repetitions of "a"
 *   34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F
 */

#define SHA1HANDSOFF		/* Copies data before messing with it. */

#include "xp_sha1.h"


/*
 * Hash a single 512-bit block. This is the core of the algorithm.
 */
void xp_SHA1::SHA1Transform(u_int32_t state[5], const u_char buffer[64]) {
    u_int32_t a, b, c, d, e;
    typedef union {
	u_char c[64];
	u_int l[16];
    } CHAR64LONG16;
    CHAR64LONG16 *block;

#ifdef SHA1HANDSOFF
    static u_char workspace[64];
    block = (CHAR64LONG16 *)workspace;
    (void)memcpy(block, buffer, 64);
#else
    block = (CHAR64LONG16 *)buffer;
#endif

    /* Copy context->state[] to working vars */
    a = state[0];
    b = state[1];
    c = state[2];
    d = state[3];
    e = state[4];

    /* 4 rounds of 20 operations each. Loop unrolled. */
    R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
    R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
    R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
    R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
    R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
    R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
    R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
    R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
    R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
    R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
    R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
    R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
    R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
    R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
    R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
    R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
    R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
    R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
    R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
    R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);

    /* Add the working vars back into context.state[] */
    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
    state[4] += e;

    /* Wipe variables */
    a = b = c = d = e = 0;
}


/*
 * SHA1Init - Initialize new context
 */
void xp_SHA1::SHA1Init(SHA1_CTX *context) {

    /* SHA1 initialization constants */
    context->state[0] = 0x67452301;
    context->state[1] = 0xEFCDAB89;
    context->state[2] = 0x98BADCFE;
    context->state[3] = 0x10325476;
    context->state[4] = 0xC3D2E1F0;
    context->count[0] = context->count[1] = 0;
}


/*
 * Run your data through this.
 */
void xp_SHA1::SHA1Update(SHA1_CTX *context, const u_char *data, u_int len) {
    u_int i, j;

    j = context->count[0];
    if ((context->count[0] += len << 3) < j)
	context->count[1] += (len>>29)+1;
    j = (j >> 3) & 63;
    if ((j + len) > 63) {
	(void)memcpy(&context->buffer[j], data, (i = 64-j));
	SHA1Transform(context->state, context->buffer);
	for ( ; i + 63 < len; i += 64)
	    SHA1Transform(context->state, &data[i]);
	j = 0;
    } else {
	i = 0;
    }
    (void)memcpy(&context->buffer[j], &data[i], len - i);
}


/*
 * Add padding and return the message digest.
 */
void xp_SHA1::SHA1Final(u_char digest[20], SHA1_CTX *context) {
    u_int i;
    u_char finalcount[8];

    for (i = 0; i < 8; i++) {
	finalcount[i] = (u_char)((context->count[(i >= 4 ? 0 : 1)]
	 >> ((3-(i & 3)) * 8) ) & 255);	 /* Endian independent */
    }
    SHA1Update(context, (const u_char *)"\200", 1);
    while ((context->count[0] & 504) != 448)
	SHA1Update(context, (const u_char *)"\0", 1);
    SHA1Update(context, finalcount, 8);  /* Should cause a SHA1Transform() */

    if (digest) {
	for (i = 0; i < 20; i++)
	    digest[i] = (u_char)
		((context->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
    }
}

int xp_SHA1::get_digest(u_char digest[20], const u_char *data, u_int len) {
	SHA1_CTX cntxt;

	SHA1Init(&cntxt);
	SHA1Update(&cntxt, data, len);
	SHA1Final(digest, &cntxt);
    return 0;
}
