/************************************************************************************* 
  This file is a part of CrashRpt library.

  Copyright (c) 2003, Michael Carruth
  All rights reserved.
 
  Redistribution and use in source and binary forms, with or without modification, 
  are permitted provided that the following conditions are met:
 
   * Redistributions of source code must retain the above copyright notice, this 
     list of conditions and the following disclaimer.
 
   * Redistributions in binary form must reproduce the above copyright notice, 
     this list of conditions and the following disclaimer in the documentation 
     and/or other materials provided with the distribution.
 
   * Neither the name of the author nor the names of its contributors 
     may be used to endorse or promote products derived from this software without 
     specific prior written permission.
 

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY 
  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 
  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
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***************************************************************************************/

/*
 * 	This is the C++ implementation of the MD5 Message-Digest
 * 	Algorithm desrcipted in RFC 1321.
 * 	I translated the C code from this RFC to C++.
 * 	There is no warranty.
 * 
 * 	Feb. 12. 2005
 * 	Benjamin Grüdelbach
 */

/*
 *	Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
 *	rights reserved.
 *
 *	License to copy and use this software is granted provided that it
 *	is identified as the "RSA Data Security, Inc. MD5 Message-Digest
 *	Algorithm" in all material mentioning or referencing this software
 *	or this function.
 *
 *	License is also granted to make and use derivative works provided
 *	that such works are identified as "derived from the RSA Data
 *	Security, Inc. MD5 Message-Digest Algorithm" in all material
 *	mentioning or referencing the derived work.
 *
 *	RSA Data Security, Inc. makes no representations concerning either
 *	the merchantability of this software or the suitability of this
 *	software for any particular purpose. It is provided "as is"
 *	without express or implied warranty of any kind.
 *
 *	These notices must be retained in any copies of any part of this
 *	documentation and/or software.
 */

//md5 class include
#include "md5.h"

// Constants for MD5Transform routine.
#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

static unsigned char PADDING[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
};

/* F, G, H and I are basic MD5 functions. */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits. */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
//#define ROTATE_LEFT(x, n) (((x) << (n)) | (( (UINT32) x) >> (32-(n))))

/*
FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
Rotation is separate from addition to prevent recomputation.
*/
#define FF(a, b, c, d, x, s, ac) { \
 (a) += F ((b), (c), (d)) + (x) + (unsigned long int)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }

#define GG(a, b, c, d, x, s, ac) { \
 (a) += G ((b), (c), (d)) + (x) + (unsigned long int)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define HH(a, b, c, d, x, s, ac) { \
 (a) += H ((b), (c), (d)) + (x) + (unsigned long int)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define II(a, b, c, d, x, s, ac) { \
 (a) += I ((b), (c), (d)) + (x) + (unsigned long int)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }

/* MD5 initialization. Begins an MD5 operation, writing a new context. */
void MD5::MD5Init (MD5_CTX *context)
{
	  context->count[0] = context->count[1] = 0;
	  context->state[0] = 0x67452301;
	  context->state[1] = 0xefcdab89;
	  context->state[2] = 0x98badcfe;
	  context->state[3] = 0x10325476;
}

/*
	 MD5 block update operation. Continues an MD5 message-digest
	 operation, processing another message block, and updating the
	 context.
*/
void MD5::MD5Update (MD5_CTX *context, unsigned char *input, unsigned int inputLen)
{
	  unsigned int i, index, partLen;

	  /* Compute number of bytes mod 64 */
	  index = (unsigned int)((context->count[0] >> 3) & 0x3F);

	  /* Update number of bits */
	  if ( (context->count[0] += ((unsigned long int)inputLen << 3))
	       < ((unsigned long int)inputLen << 3))
		context->count[1]++;

	  context->count[1] += ((unsigned long int)inputLen >> 29);
	  partLen = 64 - index;

	  /*
	   * Transform as many times as possible.
	   */
	  if (inputLen >= partLen) 
	  {
		 MD5_memcpy ((POINTER)&context->buffer[index], (POINTER)input, partLen);
		 MD5Transform (context->state, context->buffer);

		 for (i = partLen; i + 63 < inputLen; i += 64)
		   MD5Transform (context->state, &input[i]);

		 index = 0;
	  }
	  else 
	 	i = 0;

	  /* Buffer remaining input */
	  MD5_memcpy ((POINTER)&context->buffer[index],
	              (POINTER)&input[i],
		      inputLen-i);
}

/*
 * MD5 finalization. Ends an MD5 message-digest operation, writing the
 * the message digest and zeroizing the context.
 */
void MD5::MD5Final (unsigned char digest[16], MD5_CTX *context)
{
	unsigned char bits[8];
	unsigned int index, padLen;

	/* Save number of bits */
	Encode (bits, context->count, 8);

	/* 
	 * Pad out to 56 mod 64.
	 */
	index = (unsigned int)((context->count[0] >> 3) & 0x3f);
	padLen = (index < 56) ? (56 - index) : (120 - index);
	MD5Update (context, PADDING, padLen);

	/* Append length (before padding) */
	MD5Update (context, bits, 8);

	/* Store state in digest */
	Encode (digest, context->state, 16);

	/*
	 * Zeroize sensitive information.
	 */
	MD5_memset ((POINTER)context, 0, sizeof (*context));
}

/*
 * MD5 basic transformation. Transforms state based on block.
 */
void MD5::MD5Transform (unsigned long int state[4], unsigned char block[64])
{
	unsigned long int a = state[0], b = state[1], c = state[2], d = state[3], x[16];

	Decode (x, block, 64);

	/* Round 1 */
	FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
	FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
	FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
	FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
	FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
	FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
	FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
	FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
	FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
	FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
	FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
	FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
	FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
	FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
	FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
	FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

	/* Round 2 */
	GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
	GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
	GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
	GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
	GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
	GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
	GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
	GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
	GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
	GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
	GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */

	GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
	GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
	GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
	GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
	GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

	/* Round 3 */
	HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
	HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
	HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
	HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
	HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
	HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
	HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
	HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
	HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
	HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
	HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
	HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
	HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
	HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
	HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
	HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */

	/* Round 4 */
	II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
	II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
	II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
	II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
	II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
	II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
	II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
	II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
	II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
	II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
	II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
	II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
	II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
	II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
	II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
	II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */

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

	/* 
	 * Zeroize sensitive information.
	 */
	MD5_memset ((POINTER)x, 0, sizeof (x));
}

/* 
 * Encodes input (unsigned long int) into output (unsigned char). Assumes len is
 * a multiple of 4.
 */
void MD5::Encode (unsigned char *output, unsigned long int *input, unsigned int len)
{
	unsigned int i, j;

	for (i = 0, j = 0; j < len; i++, j += 4) {
		output[j] = (unsigned char)(input[i] & 0xff);
		output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
		output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
		output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
	}
}

/*
 * Decodes input (unsigned char) into output (unsigned long int). Assumes len is
 * a multiple of 4.
 */
void MD5::Decode (unsigned long int *output, unsigned char *input, unsigned int len)
{
	  unsigned int i, j;

	  for (i = 0, j = 0; j < len; i++, j += 4)
		 output[i] = ((unsigned long int)input[j]) | 
			     (((unsigned long int)input[j+1]) << 8) |
			     (((unsigned long int)input[j+2]) << 16) |
			     (((unsigned long int)input[j+3]) << 24);
}

/*
 * Note: Replace "for loop" with standard memcpy if possible.
 */
void MD5::MD5_memcpy (POINTER output, POINTER input, unsigned int len)
{
	unsigned int i;

	for (i = 0; i < len; i++)
		output[i] = input[i];
}

/*
 * Note: Replace "for loop" with standard memset if possible.
 */
void MD5::MD5_memset (POINTER output,int value,unsigned int len)
{
	unsigned int i;
	for (i = 0; i < len; i++)
		((char *)output)[i] = (char)value;
}

/*
 * EOF
 */
