md5.cpp

/*
 *      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 Gr�delbach
 */

/*
 *      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 uint8_t 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) + (uint32_t)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }

#define GG(a, b, c, d, x, s, ac) { \
 (a) += G ((b), (c), (d)) + (x) + (uint32_t)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define HH(a, b, c, d, x, s, ac) { \
 (a) += H ((b), (c), (d)) + (x) + (uint32_t)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define II(a, b, c, d, x, s, ac) { \
 (a) += I ((b), (c), (d)) + (x) + (uint32_t)(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, uint8_t *input, uint32_t inputLen) {
  uint32_t i, index, partLen;

  /* Compute number of bytes mod 64 */
  index = (uint32_t)((context->count[0] >> 3) & 0x3F);

  /* Update number of bits */
  if((context->count[0] += ((uint32_t)inputLen << 3))
      < ((uint32_t)inputLen << 3))
    context->count[1]++;

  context->count[1] += ((uint32_t)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(uint8_t digest[16], MD5_CTX *context) {
  uint8_t bits[8];
  uint32_t index, padLen;

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

  /*
   * Pad out to 56 mod 64.
   */
  index = (uint32_t)((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(uint32_t state[4], uint8_t block[64]) {
  uint32_t 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 (uint32_t) into output (uint8_t). Assumes len is
 * a multiple of 4.
 */
void MD5::Encode(uint8_t *output, uint32_t *input, uint32_t len) {
  uint32_t i, j;

  for(i = 0, j = 0; j < len; i++, j += 4) {
    output[j] = (uint8_t)(input[i] & 0xff);
    output[j+1] = (uint8_t)((input[i] >> 8) & 0xff);
    output[j+2] = (uint8_t)((input[i] >> 16) & 0xff);
    output[j+3] = (uint8_t)((input[i] >> 24) & 0xff);
  }
}

/*
 * Decodes input (uint8_t) into output (uint32_t). Assumes len is
 * a multiple of 4.
 */
void MD5::Decode(uint32_t *output, uint8_t *input, uint32_t len) {
  uint32_t i, j;

  for(i = 0, j = 0; j < len; i++, j += 4)
    output[i] = ((uint32_t)input[j]) |
                (((uint32_t)input[j+1]) << 8) |
                (((uint32_t)input[j+2]) << 16) |
                (((uint32_t)input[j+3]) << 24);
}

/*
 * Note: Replace "for loop" with standard memcpy if possible.
 */
void MD5::MD5_memcpy(POINTER output, POINTER input, uint32_t len) {
  uint32_t 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, int32_t value, uint32_t len) {
  uint32_t i;
  for(i = 0; i < len; i++)
    ((int8_t *)output)[i] = (int8_t)value;
}

/*
 * EOF
 */