// Copyright (C) 1999-2001 Open Source Telecom Corporation.
//  
// 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.
// 
// As a special exception to the GNU General Public License, permission is 
// granted for additional uses of the text contained in its release 
// of Common C++.
// 
// The exception is that, if you link the Common C++ library with other files
// to produce an executable, this does not by itself cause the
// resulting executable to be covered by the GNU General Public License.
// Your use of that executable is in no way restricted on account of
// linking the Common C++ library code into it.
// 
// This exception does not however invalidate any other reasons why
// the executable file might be covered by the GNU General Public License.
// 
// This exception applies only to the code released under the 
// name Common C++.  If you copy code from other releases into a copy of
// Common C++, as the General Public License permits, the exception does
// not apply to the code that you add in this way.  To avoid misleading
// anyone as to the status of such modified files, you must delete
// this exception notice from them.
// 
// If you write modifications of your own for Common C++, it is your choice
// whether to permit this exception to apply to your modifications.
// If you do not wish that, delete this exception notice.  

#include "digest.h"

	

#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21

inline unsigned long rotate_left(unsigned long x, unsigned long n)
{
	return (x << n) | (x >> (32-n));
}

inline unsigned long F(unsigned long x, unsigned long y, unsigned long z)
{
	return (x & y) | (~x & z);
}
 
inline unsigned long G(unsigned long x, unsigned long y, unsigned long z)
{
	return (x & z) | (y & ~z);
}
 
inline unsigned long H(unsigned long x, unsigned long y, unsigned long z)
{
	return x ^ y ^ z;
}
 
inline unsigned long I(unsigned long x, unsigned long y, unsigned long z)
{
	return y ^ (x | ~z);
}

   
static void FF(unsigned long &a, unsigned long b, unsigned long c, unsigned long d, unsigned long x, unsigned long s, unsigned long ac)
{
	a += F(b, c, d) + x + ac;
	a = rotate_left(a, s) + b;
}

static void GG(unsigned long &a, unsigned long b, unsigned long c, unsigned long d, unsigned long x, unsigned long s, unsigned long ac)
{
	a += G(b, c, d) + x + ac;
	a = rotate_left(a, s) + b;
}

static void HH(unsigned long &a, unsigned long b, unsigned long c, unsigned long d, unsigned long x, unsigned long s, unsigned long ac)
{
	a += H(b, c, d) + x + ac;
	a = rotate_left(a, s) + b;
}

static void II(unsigned long &a, unsigned long b, unsigned long c, unsigned long d, unsigned long x, unsigned long s, unsigned long ac)
{
	a += I(b, c, d) + x + ac;
	a = rotate_left(a, s) + b;
}

MD5Digest::MD5Digest() :
Digest()
{
	initDigest();
	updated = true;
}

void MD5Digest::initDigest(void)
{
	count[0] = count[1] = 0;
	state[0] = 0x67452301;
	state[1] = 0xefcdab89;
	state[2] = 0x98badcfe;
	state[3] = 0x10325476;
	bpos = 0;
	updated = false;
}

int MD5Digest::overflow(int c)
{
	updated = true;
	buf[bpos++] = (unsigned char)c;
	if(bpos >= 64)
		Update();

	return c;
}

void MD5Digest::Update(void)
{
	unsigned long x[16], a, b, c, d;
	int i;

	if(!bpos)
		return;

	while(bpos < 64)
		buf[bpos++] = 0;

	if((count[0] += 512) < 512)
		++count[1];

	a = state[0];
	b = state[1];
	c = state[2];
	d = state[3];

	for(i = 0; i < 16; ++i)
		x[i] = (unsigned long)(buf[i * 4]) |
			(unsigned long)(buf[i * 4 + 1] << 8) |
			(unsigned long)(buf[i * 4 + 2] << 16) |
			(unsigned long)(buf[i * 4 + 3] << 24);

	FF(a, b, c, d, x[ 0], S11, 0xd76aa478);
  	FF(d, a, b, c, x[ 1], S12, 0xe8c7b756);
  	FF(c, d, a, b, x[ 2], S13, 0x242070db);
  	FF(b, c, d, a, x[ 3], S14, 0xc1bdceee);
  	FF(a, b, c, d, x[ 4], S11, 0xf57c0faf);
  	FF(d, a, b, c, x[ 5], S12, 0x4787c62a);
  	FF(c, d, a, b, x[ 6], S13, 0xa8304613);
  	FF(b, c, d, a, x[ 7], S14, 0xfd469501);
  	FF(a, b, c, d, x[ 8], S11, 0x698098d8);
  	FF(d, a, b, c, x[ 9], S12, 0x8b44f7af);
  	FF(c, d, a, b, x[10], S13, 0xffff5bb1);
  	FF(b, c, d, a, x[11], S14, 0x895cd7be);
  	FF(a, b, c, d, x[12], S11, 0x6b901122);
  	FF(d, a, b, c, x[13], S12, 0xfd987193);
  	FF(c, d, a, b, x[14], S13, 0xa679438e);
  	FF(b, c, d, a, x[15], S14, 0x49b40821);

	GG(a, b, c, d, x[ 1], S21, 0xf61e2562);
	GG(d, a, b, c, x[ 6], S22, 0xc040b340);
	GG(c, d, a, b, x[11], S23, 0x265e5a51);
	GG(b, c, d, a, x[ 0], S24, 0xe9b6c7aa);
	GG(a, b, c, d, x[ 5], S21, 0xd62f105d);
	GG(d, a, b, c, x[10], S22,  0x2441453);
	GG(c, d, a, b, x[15], S23, 0xd8a1e681);
	GG(b, c, d, a, x[ 4], S24, 0xe7d3fbc8);
	GG(a, b, c, d, x[ 9], S21, 0x21e1cde6);
	GG(d, a, b, c, x[14], S22, 0xc33707d6);
	GG(c, d, a, b, x[ 3], S23, 0xf4d50d87);
	GG(b, c, d, a, x[ 8], S24, 0x455a14ed);
	GG(a, b, c, d, x[13], S21, 0xa9e3e905);
	GG(d, a, b, c, x[ 2], S22, 0xfcefa3f8);
	GG(c, d, a, b, x[ 7], S23, 0x676f02d9);
	GG(b, c, d, a, x[12], S24, 0x8d2a4c8a);

	HH(a, b, c, d, x[ 5], S31, 0xfffa3942);
	HH(d, a, b, c, x[ 8], S32, 0x8771f681);
	HH(c, d, a, b, x[11], S33, 0x6d9d6122);
	HH(b, c, d, a, x[14], S34, 0xfde5380c);
	HH(a, b, c, d, x[ 1], S31, 0xa4beea44);
	HH(d, a, b, c, x[ 4], S32, 0x4bdecfa9);
	HH(c, d, a, b, x[ 7], S33, 0xf6bb4b60);
	HH(b, c, d, a, x[10], S34, 0xbebfbc70);
	HH(a, b, c, d, x[13], S31, 0x289b7ec6);
	HH(d, a, b, c, x[ 0], S32, 0xeaa127fa);
	HH(c, d, a, b, x[ 3], S33, 0xd4ef3085);
	HH(b, c, d, a, x[ 6], S34,  0x4881d05);
	HH(a, b, c, d, x[ 9], S31, 0xd9d4d039);
	HH(d, a, b, c, x[12], S32, 0xe6db99e5);
	HH(c, d, a, b, x[15], S33, 0x1fa27cf8);
	HH(b, c, d, a, x[ 2], S34, 0xc4ac5665); 

	II(a, b, c, d, x[ 0], S41, 0xf4292244);
	II(d, a, b, c, x[ 7], S42, 0x432aff97);
	II(c, d, a, b, x[14], S43, 0xab9423a7);
	II(b, c, d, a, x[ 5], S44, 0xfc93a039);
	II(a, b, c, d, x[12], S41, 0x655b59c3);
	II(d, a, b, c, x[ 3], S42, 0x8f0ccc92);
	II(c, d, a, b, x[10], S43, 0xffeff47d);
	II(b, c, d, a, x[ 1], S44, 0x85845dd1);
	II(a, b, c, d, x[ 8], S41, 0x6fa87e4f);
	II(d, a, b, c, x[15], S42, 0xfe2ce6e0);
	II(c, d, a, b, x[ 6], S43, 0xa3014314);
	II(b, c, d, a, x[13], S44, 0x4e0811a1);
	II(a, b, c, d, x[ 4], S41, 0xf7537e82);
	II(d, a, b, c, x[11], S42, 0xbd3af235);
	II(c, d, a, b, x[ 2], S43, 0x2ad7d2bb);
	II(b, c, d, a, x[ 9], S44, 0xeb86d391);

	state[0] += a;
	state[1] += b;
	state[2] += c;
	state[3] += d;
	updated = true;
}

void MD5Digest::Commit(void)
{
	unsigned char cbuf[8];
	unsigned long i, len;

 	static unsigned char pad[64]={
    		0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

	if(!updated && !bpos)
		return;

	count[0] += (unsigned long)(bpos << 3);
	if(count[0] < (unsigned long)(bpos << 3))
		++count[1];

	for(i = 0; i < 2; ++i)
	{
		cbuf[i * 4] = (unsigned char)count[i] & 0xff;
		cbuf[i * 4 + 1] = (unsigned char)((count[i] >> 8) & 0xff);
		cbuf[i * 4 + 2] = (unsigned char)((count[i] >> 16) & 0xff);
		cbuf[i * 4 + 3] = (unsigned char)((count[i] >> 24) & 0xff);
	}

	i = (unsigned) ((count[0] >> 3) & 0x3f);
  	len = (i < 56) ? (56 - i) : (120 - i);
	if(len)
		putDigest(pad, len);

	putDigest(cbuf, 8);

	for(i = 0; i < 4; ++i)
	{
		md5[i * 4] = (unsigned char)state[i] & 0xff;
                md5[i * 4 + 1] = (unsigned char)((state[i] >> 8) & 0xff);
                md5[i * 4 + 2] = (unsigned char)((state[i] >> 16) & 0xff);
                md5[i * 4 + 3] = (unsigned char)((state[i] >> 24) & 0xff);
	}
	initDigest();
}

unsigned MD5Digest::getDigest(unsigned char *buffer)
{
	Commit();

	memcpy(buffer, md5, 16);
	return 16;
}

void MD5Digest::putDigest(unsigned char *buffer, unsigned len)
{
	while(len--)
	{
		buf[bpos++] = *(buffer++);
		if(bpos >= 64)
			Update();
	}
}

char* MD5Digest::stringDigest() {
  char *buf;
  buf = new char[33];
  int i;

  Commit();

  for(i = 0; i < 16; ++i)
    sprintf(buf + 2 * i, "%02x", md5[i]);

  return buf;
}