sha1.cpp

Last change: 2008-02-03 This is the source code of KCeasy。

/*
This file is part of KCeasy (http://www.kceasy.com)
Copyright (C) 2002-2004 Markus Kern <[e-mail]>

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.

Based on:

(PD) 2001 The Bitzi Corporation
Please see http://bitzi.com/publicdomain for more info.

NIST Secure Hash Algorithm
heavily modified by Uwe Hollerbach <[e-mail] edu>
from Peter C. Gutmann's implementation as found in
Applied Cryptography by Bruce Schneier
Further modifications to include the "UNRAVEL" stuff, below
*/
//---------------------------------------------------------------------------
#include <stdio.h>
#include <sys\stat.h> // stat
#include <string.h> // memcpy
#include "Sha1.h"
//---------------------------------------------------------------------------

#if 1
#define GET_BE32(p,ind) \
	((p)[ind] << 24 | (p)[(ind)+1] << 16 | (p)[(ind)+2] << 8 | (p)[(ind)+3])
#else
#define GET_BE32(p32,ind) \
	ntohl((p32)[(ind)/4])
#endif

#define COPY_BE32x16(W,wind,p,ind)             \
    (W)[(wind)]   = GET_BE32((p),(ind));       \
    (W)[(wind)+1] = GET_BE32((p),(ind)+4);     \
    (W)[(wind)+2] = GET_BE32((p),(ind)+8);     \
    (W)[(wind)+3] = GET_BE32((p),(ind)+12);

/* SHA f()-functions */

#define f1(x,y,z)		((x & y) | (~x & z))
#define f2(x,y,z)		(x ^ y ^ z)
#define f3(x,y,z)		((x & y) | (x & z) | (y & z))
#define f4(x,y,z)		(x ^ y ^ z)

/* truncate to 32 bits -- should be a null op on 32-bit machines */

#define T32(x)	((x) & 0xffffffffL)

/* 32-bit rotate */

#define R32(x,n)		T32(((x << n) | (x >> (32 - n))))

#define CONST1			0x5a827999L
#define CONST2			0x6ed9eba1L
#define CONST3			0x8f1bbcdcL
#define CONST4			0xca62c1d6L

/* the generic case, for when the overall rotation is not unraveled */

#define FG(n)	\
	T = T32(R32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n);		\
	E = D; D = C; C = R32(B,30); B = A; A = T

/* specific cases, for when the overall rotation is unraveled */

#define FA(n)	\
	T = T32(R32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n); B = R32(B,30)

#define FB(n)	\
	E = T32(R32(T,5) + f##n(A,B,C) + D + *WP++ + CONST##n); A = R32(A,30)

#define FC(n)	\
	D = T32(R32(E,5) + f##n(T,A,B) + C + *WP++ + CONST##n); T = R32(T,30)

#define FD(n)	\
	C = T32(R32(D,5) + f##n(E,T,A) + B + *WP++ + CONST##n); E = R32(E,30)

#define FE(n)	\
	B = T32(R32(C,5) + f##n(D,E,T) + A + *WP++ + CONST##n); D = R32(D,30)

#define FT(n)	\
	A = T32(R32(B,5) + f##n(C,D,E) + T + *WP++ + CONST##n); C = R32(C,30)

//---------------------------------------------------------------------------

TKSHA1::TKSHA1()
{
	digest[0] = 0x67452301L;
	digest[1] = 0xefcdab89L;
	digest[2] = 0x98badcfeL;
	digest[3] = 0x10325476L;
	digest[4] = 0xc3d2e1f0L;

	count_lo = 0L;
	count_hi = 0L;
	local = 0;
}

TKSHA1::~TKSHA1()
{
}

void TKSHA1::Update(const void *buf, unsigned int len)
{
	int i;
	unsigned long clo;
	const unsigned char *buffer = (unsigned char*)buf;

	clo = T32(count_lo + ((unsigned long) len << 3));
	if (clo < count_lo) {
		++count_hi;
	}
	count_lo = clo;
	count_hi += (unsigned long) len >> 29;
	if (local) {
		i = KSHA_BLOCKSIZE - local;
		if (i > len) {
			i = len;
		}
		memcpy(((unsigned char*)data) + local, buffer, i);
		len -= i;
		buffer += i;
		local += i;
		if (local == KSHA_BLOCKSIZE) {
			Transform();
		} else {
			return;
		}
	}
	while (len >= KSHA_BLOCKSIZE) {
		memcpy(((unsigned char*)data), buffer, KSHA_BLOCKSIZE);
		buffer += KSHA_BLOCKSIZE;
		len -= KSHA_BLOCKSIZE;
		Transform();
	}
	memcpy(((unsigned char*)data), buffer, len);
	local = len;
}

void TKSHA1::Final(unsigned char *hash)
{
	int count;
	unsigned long lo_bit_count, hi_bit_count;

	lo_bit_count = count_lo;
	hi_bit_count = count_hi;
	count = (int) ((lo_bit_count >> 3) & 0x3f);
	data[count++] = 0x80;
	if (count > KSHA_BLOCKSIZE - 8) {
		memset(data + count, 0, KSHA_BLOCKSIZE - count);
		Transform();
		memset(data, 0, KSHA_BLOCKSIZE - 8);
	} else {
		memset(data + count, 0,
			KSHA_BLOCKSIZE - 8 - count);
	}
	data[56] = (unsigned char) ((hi_bit_count >> 24) & 0xff);
	data[57] = (unsigned char) ((hi_bit_count >> 16) & 0xff);
	data[58] = (unsigned char) ((hi_bit_count >>	8) & 0xff);
	data[59] = (unsigned char) ((hi_bit_count >>	0) & 0xff);
	data[60] = (unsigned char) ((lo_bit_count >> 24) & 0xff);
	data[61] = (unsigned char) ((lo_bit_count >> 16) & 0xff);
	data[62] = (unsigned char) ((lo_bit_count >>	8) & 0xff);
	data[63] = (unsigned char) ((lo_bit_count >>	0) & 0xff);
	Transform();
	hash[ 0] = (unsigned char) ((digest[0] >> 24) & 0xff);
	hash[ 1] = (unsigned char) ((digest[0] >> 16) & 0xff);
	hash[ 2] = (unsigned char) ((digest[0] >>  8) & 0xff);
	hash[ 3] = (unsigned char) ((digest[0]		) & 0xff);
	hash[ 4] = (unsigned char) ((digest[1] >> 24) & 0xff);
	hash[ 5] = (unsigned char) ((digest[1] >> 16) & 0xff);
	hash[ 6] = (unsigned char) ((digest[1] >>  8) & 0xff);
	hash[ 7] = (unsigned char) ((digest[1]		) & 0xff);
	hash[ 8] = (unsigned char) ((digest[2] >> 24) & 0xff);
	hash[ 9] = (unsigned char) ((digest[2] >> 16) & 0xff);
	hash[10] = (unsigned char) ((digest[2] >>  8) & 0xff);
	hash[11] = (unsigned char) ((digest[2]		) & 0xff);
	hash[12] = (unsigned char) ((digest[3] >> 24) & 0xff);
	hash[13] = (unsigned char) ((digest[3] >> 16) & 0xff);
	hash[14] = (unsigned char) ((digest[3] >>  8) & 0xff);
	hash[15] = (unsigned char) ((digest[3]		) & 0xff);
	hash[16] = (unsigned char) ((digest[4] >> 24) & 0xff);
	hash[17] = (unsigned char) ((digest[4] >> 16) & 0xff);
	hash[18] = (unsigned char) ((digest[4] >>  8) & 0xff);
	hash[19] = (unsigned char) ((digest[4]		) & 0xff);
}

#undef MIN
#define MIN(a,b) ((a) < (b) ? (a) : (b))

bool TKSHA1::HashFile(const char *File, unsigned int Start, unsigned int Length)
{
	FILE *f;
	unsigned char *hash;
	unsigned int len;
	int n;
	struct stat st;
	char buf[1024*16];

	if ((f = fopen (File, "rb")) == NULL)
		return false;

	if (stat (File, &st) == -1)
	{
		fclose (f);
		return false;
	}

	if (Length == 0)
		Length = st.st_size;

    if (Start >= st.st_size || fseek (f, Start, SEEK_SET) != 0)
    {
		fclose (f);
		return false;
    }

    Length = MIN (st.st_size - Start, Length);

	while (Length > 0)
	{
		len = MIN (sizeof (buf), Length);

		n = fread (buf, 1, len, f);

		if (n == 0 || n != len)
			break;

		Update ((unsigned char *) buf, len);
		Length -= len;
	}

	fclose (f);

	if (Length != 0)
		return false;

	return true;
}

//---------------------------------------------------------------------------

void TKSHA1::Transform()
{
	int i;
	unsigned char *dp;
	unsigned long T, A, B, C, D, E, W[80], *WP;

	dp = data;

	COPY_BE32x16(W, 0,dp,0);
	COPY_BE32x16(W, 4,dp,16);
	COPY_BE32x16(W, 8,dp,32);
	COPY_BE32x16(W,12,dp,48);

	for (i = 16; i < 80; ++i) {
		W[i] = W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16];
		W[i] = R32(W[i], 1);
	}

	A = digest[0];
	B = digest[1];
	C = digest[2];
	D = digest[3];
	E = digest[4];
	WP = W;

	FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1); FC(1); FD(1);
	FE(1); FT(1); FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1);
	FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2); FE(2); FT(2);
	FA(2); FB(2); FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2);
	FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3); FA(3); FB(3);
	FC(3); FD(3); FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3);
	FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4); FC(4); FD(4);
	FE(4); FT(4); FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4);

	digest[0] = T32(digest[0] + E);
	digest[1] = T32(digest[1] + T);
	digest[2] = T32(digest[2] + A);
	digest[3] = T32(digest[3] + B);
	digest[4] = T32(digest[4] + C);
}

//---------------------------------------------------------------------------