GenMD5.cc

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// MD5.CC - source code for the C++/object oriented translation and 
//          modification of MD5.

// Translation and modification (c) 1995 by Mordechai T. Abzug 

// This translation/ modification is provided "as is," without express or 
// implied warranty of any kind.

// The translator/ modifier does not claim (1) that MD5 will do what you think 
// it does; (2) that this translation/ modification is accurate; or (3) that 
// this software is "merchantible."  (Language for this disclaimer partially 
// copied from the disclaimer below).

/* based on:

   MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
   MDDRIVER.C - test driver for MD2, MD4 and MD5


   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.

*/
#include <cassert>
#include <string>
#include <cstdio>
#include <cstring>
#include <iostream>

using namespace std;

// Constants for MD5Transform routine.
// Although we could use C++ style constants, defines are actually better,
// since they let us easily evade scope clashes.
#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

namespace {
  class MD5 {
  public:
    MD5              (unsigned char* buffer, unsigned long len);
    MD5              ();  
    void  update     (unsigned char *input, unsigned int input_length);
    // Finalize MD5 check-sum
    void  finalize   ();

    void raw_digest (unsigned char *buff);

    string       hex_digest ();

  private:
    // next, the private data:
    unsigned int state[4];
    unsigned int count[2];     // number of *bits*, mod 2^64
    unsigned char buffer[64];   // input buffer
    unsigned char digest[16];
    unsigned char finalized;

    // last, the private methods, mostly static:
    void init             ();               // called by all constructors
    void transform        (unsigned char *buffer);  // does the real update work.  Note 
                                            // that length is implied to be 64.

    static void encode    (unsigned char *dest, unsigned int *src, unsigned int length);
    static void decode    (unsigned int *dest, unsigned char *src, unsigned int length);

    // ROTATE_LEFT rotates x left n bits.
    static inline unsigned int  rotate_left (unsigned int x, unsigned int n)
    {  return (x << n) | (x >> (32-n));                             }
    // F, G, H and I are basic MD5 functions.
    static inline unsigned int  F(unsigned int x, unsigned int y, unsigned int z)
    {  return (x & y) | (~x & z);                                   }
    static inline unsigned int  G(unsigned int x, unsigned int y, unsigned int z)
    {  return (x & z) | (y & ~z);                                   }
    static inline unsigned int  H(unsigned int x, unsigned int y, unsigned int z)
    {  return x ^ y ^ z;                                            }
    static inline unsigned int  I(unsigned int x, unsigned int y, unsigned int z)
    {  return y ^ (x | ~z);                                         }

    // FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
    // Rotation is separate from addition to prevent recomputation.
    static inline void   FF  (unsigned int& a, unsigned int b, unsigned int c, unsigned int d, unsigned int x, unsigned int s, unsigned int ac)
    {
     a += F(b, c, d) + x + ac;
     a = rotate_left(a, s) + b;
    }
    static inline void   GG  (unsigned int& a, unsigned int b, unsigned int c, unsigned int d, unsigned int x, unsigned int s, unsigned int ac)
    {
     a += G(b, c, d) + x + ac;
     a = rotate_left(a, s) + b;
    }
    static inline void   HH  (unsigned int& a, unsigned int b, unsigned int c, unsigned int d, unsigned int x, unsigned int s, unsigned int ac)
    {
     a += H(b, c, d) + x + ac;
     a = rotate_left(a, s) + b;
    }
    static inline void   II  (unsigned int& a, unsigned int b, unsigned int c, unsigned int d, unsigned int x, unsigned int s, unsigned int ac)
    {
     a += I(b, c, d) + x + ac;
     a = rotate_left(a, s) + b;
    }
  };
}

// MD5 simple initialization method
MD5::MD5()    {
  init();
}

// MD5 simple initialization method
MD5::MD5(unsigned char* buffer, unsigned long len)    {
  init();
  update(buffer, len);
  finalize();
}

// MD5 block update operation. Continues an MD5 message-digest
// operation, processing another message block, and updating the
// context.
void MD5::update (unsigned char *input, unsigned int input_length) {
  unsigned int idx, index, space;
  if ( finalized ) {  // so we can't update!
    cerr << "MD5::update:  Can't update a finalized digest!" << endl;
    return;
  }
  // Compute number of bytes mod 64
  index = (unsigned int)((count[0] >> 3) & 0x3F);
  // Update number of bits
  if (  (count[0] += ((unsigned int) input_length << 3))<((unsigned int) input_length << 3) )
    count[1]++;

  count[1] += ((unsigned int)input_length >> 29);
  space = 64 - index;  // how much space is left in buffer
  // Transform as many times as possible.
  if (input_length >= space) { // ie. we have enough to fill the buffer
    // fill the rest of the buffer and transform
    memcpy (buffer + index, input, space);
    transform (buffer);
    // now, transform each 64-byte piece of the input, bypassing the buffer
    for (idx = space; idx + 63 < input_length; idx += 64)
      transform (input+idx);

    index = 0;  // so we can buffer remaining
  }
  else  {
    idx = 0;    // so we can buffer the whole input
  }

  // and here we do the buffering:
  memcpy(buffer+index, input+idx, input_length-idx);
}

// MD5 finalization. Ends an MD5 message-digest operation, writing the
// the message digest and zeroizing the context.
void MD5::finalize ()     {
  unsigned char bits[8];
  unsigned int index, padLen;
  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
    };
  if (finalized){
    cerr << "MD5::finalize:  Already finalized this digest!" << endl;
    return;
  }
  // Save number of bits
  encode (bits, count, 8);
  // Pad out to 56 mod 64.
  index = (unsigned int) ((count[0] >> 3) & 0x3f);
  padLen = (index < 56) ? (56 - index) : (120 - index);
  update (PADDING, padLen);
  // Append length (before padding)
  update (bits, 8);
  // Store state in digest
  encode (digest, state, 16);
  // Zeroize sensitive information
  memset (buffer, 0, sizeof(*buffer));
  finalized=1;
}

void MD5::raw_digest(unsigned char *s){
  if (finalized){
    memcpy(s, digest, 16);
    return;
  }
  cerr << "MD5::raw_digest:  Can't get digest if you haven't "<<
    "finalized the digest!" << endl;
}

string MD5::hex_digest()   {
  char s[33];
  if (!finalized){
    cerr << "MD5::hex_digest:  Can't get digest if you haven't "<<
      "finalized the digest!" <<endl;
    return "";
  }
  for (int i=0; i<16; i++)
    sprintf(s+i*2, "%02x", digest[i]);
  s[32]='\0';
  return s;
}

// PRIVATE METHODS:
void MD5::init(){
  finalized=0;  // we just started!
  // Nothing counted, so count=0
  count[0] = 0;
  count[1] = 0;
  // Load magic initialization constants.
  state[0] = 0x67452301;
  state[1] = 0xefcdab89;
  state[2] = 0x98badcfe;
  state[3] = 0x10325476;
}

// MD5 basic transformation. Transforms state based on block.
void MD5::transform (unsigned char* block){
  unsigned int a = state[0], b = state[1], c = state[2], d = state[3], x[16];
  decode (x, block, 64);
  assert(!finalized);  // not just a user error, since the method is private
  /* 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.
  memset ( (unsigned char *) x, 0, sizeof(x));
}

// Encodes input (unsigned int) into output (unsigned char). Assumes len is
// a multiple of 4.
void MD5::encode (unsigned char *output, unsigned int *input, unsigned int len) {
  for (unsigned int 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 int). Assumes len is
// a multiple of 4.
void MD5::decode (unsigned int *output, unsigned char *input, unsigned int len){
  for (unsigned int i = 0, j = 0; j < len; i++, j += 4)
    output[i] = ((unsigned int)input[j]) | (((unsigned int)input[j+1]) << 8) |
      (((unsigned int)input[j+2]) << 16) | (((unsigned int)input[j+3]) << 24);
}

namespace cond {
  void* genMD5(void* buffer, unsigned long len, void* code)   {
    MD5 checkSum((unsigned char*)buffer, len);
    checkSum.raw_digest((unsigned char*)code);
    return code;
  }
  void genMD5(const string& s, void* code)    {
    MD5 checkSum((unsigned char*)s.c_str(), s.length());
    checkSum.raw_digest((unsigned char*)code);
  }
}