/*
 * sha1.cpp - Secure Hash Algorithm 1
 * Copyright (C) 2003  Justin Karneges
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include"sha1.h"

// CS_NAMESPACE_BEGIN

/****************************************************************************
  SHA1 - from a public domain implementation by Steve Reid (steve@edmweb.com)
****************************************************************************/

#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15]^block->l[(i+2)&15]^block->l[i&15],1))

/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);
#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);
#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
#define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);
#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);


SHA1::SHA1()
{
	int wordSize;

	qSysInfo(&wordSize, &bigEndian);
}

unsigned long SHA1::blk0(Q_UINT32 i)
{
	if(bigEndian)
		return block->l[i];
	else
		return (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) | (rol(block->l[i],8)&0x00FF00FF));
}

// Hash a single 512-bit block. This is the core of the algorithm.
void SHA1::transform(Q_UINT32 state[5], unsigned char buffer[64])
{
	Q_UINT32 a, b, c, d, e;

	block = (CHAR64LONG16*)buffer;

	// 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 SHA1::init(SHA1_CONTEXT* 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 SHA1::update(SHA1_CONTEXT* context, unsigned char* data, Q_UINT32 len)
{
	Q_UINT32 i, j;

	j = (context->count[0] >> 3) & 63;
	if((context->count[0] += len << 3) < (len << 3))
		context->count[1]++;

	context->count[1] += (len >> 29);

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

// Add padding and return the message digest
void SHA1::final(unsigned char digest[20], SHA1_CONTEXT* context)
{
	Q_UINT32 i, j;
	unsigned char finalcount[8];

	for (i = 0; i < 8; i++) {
		finalcount[i] = (unsigned char)((context->count[(i >= 4 ? 0 : 1)]
		>> ((3-(i & 3)) * 8) ) & 255);  // Endian independent
	}
	update(context, (unsigned char *)"\200", 1);
	while ((context->count[0] & 504) != 448) {
		update(context, (unsigned char *)"\0", 1);
	}
	update(context, finalcount, 8);  // Should cause a transform()
	for (i = 0; i < 20; i++) {
		digest[i] = (unsigned char) ((context->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
	}

	// Wipe variables
	i = j = 0;
	memset(context->buffer, 0, 64);
	memset(context->state, 0, 20);
	memset(context->count, 0, 8);
	memset(&finalcount, 0, 8);
}

QByteArray SHA1::hash(const QByteArray &a)
{
	SHA1_CONTEXT context;
	QByteArray b(20);

	SHA1 s;
	s.init(&context);
	s.update(&context, (unsigned char *)a.data(), (unsigned int)a.size());
	s.final((unsigned char *)b.data(), &context);
	return b;
}

QByteArray SHA1::hashString(const QCString &cs)
{
	QByteArray a(cs.length());
	memcpy(a.data(), cs.data(), a.size());
	return SHA1::hash(a);
}

QString SHA1::digest(const QString &in)
{
	QByteArray a = SHA1::hashString(in.utf8());
	QString out;
	for(int n = 0; n < (int)a.size(); ++n) {
		QString str;
		str.sprintf("%02x", (uchar)a[n]);
		out.append(str);
	}

	return out;
}

// CS_NAMESPACE_END
