text: /* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm */
  
  /* 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 "stdafx.h"
  
  #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 void MD5Transform(u32 [4], u8 [64]);
  static void Encode(u8 *, u32 *, u32);
  static void Decode(u32 *, u8 *, u32);
  
  static u8 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))))
  
  /* 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) + (u32)(ac); \
   (a) = ROTATE_LEFT ((a), (s)); \
   (a) += (b); \
    }
  #define GG(a, b, c, d, x, s, ac) { \
   (a) += G ((b), (c), (d)) + (x) + (u32)(ac); \
   (a) = ROTATE_LEFT ((a), (s)); \
   (a) += (b); \
    }
  #define HH(a, b, c, d, x, s, ac) { \
   (a) += H ((b), (c), (d)) + (x) + (u32)(ac); \
   (a) = ROTATE_LEFT ((a), (s)); \
   (a) += (b); \
    }
  #define II(a, b, c, d, x, s, ac) { \
   (a) += I ((b), (c), (d)) + (x) + (u32)(ac); \
   (a) = ROTATE_LEFT ((a), (s)); \
   (a) += (b); \
    }
  
  /* MD5 initialization. Begins an MD5 operation, writing a new context. */
  void MD5Init(MD5_CTX *context)
  {
    context->count[0] = context->count[1] = 0;
    /* Load magic initialization constants. */
    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 MD5Update(MD5_CTX *context, u8 *input, u32 inputLen)
  {
    u32 i, index, partLen;
  
    /* Compute number of bytes mod 64 */
    index = (u32)((context->count[0] >> 3) & 0x3F);
  
    /* Update number of bits */
    if ((context->count[0] += ((u32)inputLen << 3))
     < ((u32)inputLen << 3))
   context->count[1]++;
    context->count[1] += ((u32)inputLen >> 29);
  
    partLen = 64 - index;
  
    /* Transform as many times as possible. */
    if (inputLen >= partLen) {
   CopyMemory
     ((u8 *)&context->buffer[index], (u8 *)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 */
    CopyMemory
   ((u8 *)&context->buffer[index], (u8 *)&input[i],
    inputLen-i);
  }
  
  void MD5String(MD5_CTX *ctx, const char *str)
  {
  	MD5Update(ctx, (u8 *)(char *)str, (u32)strlen(str));
  }
  
  /* MD5 finalization. Ends an MD5 message-digest operation, writing
     the message digest and zeroizing the context. */
  void MD5Final(u8 digest[16] ,MD5_CTX *context)
  {
    u8 bits[8];
    u32 index, padLen;
  
    /* Save number of bits */
    Encode (bits, context->count, 8);
  
    /* Pad out to 56 mod 64. */
    index = (u32)((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. */
    ZeroMemory ((u8 *)context, sizeof (*context));
  }
  
  /* MD5 basic transformation. Transforms state based on block. */
  static void MD5Transform(u32 state[4], u8 block[64])
  {
    u32 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. */
    ZeroMemory ((u8 *)x, sizeof (x));
  }
  
  /* Encodes input (u32) into output (u8). Assumes len is
     a multiple of 4. */
  static void Encode(u8 *output, u32 *input, u32 len)
  {
    u32 i, j;
  
    for (i = 0, j = 0; j < len; i++, j += 4) {
   output[j] = (u8)(input[i] & 0xff);
   output[j+1] = (u8)((input[i] >> 8) & 0xff);
   output[j+2] = (u8)((input[i] >> 16) & 0xff);
   output[j+3] = (u8)((input[i] >> 24) & 0xff);
    }
  }
  
  /* Decodes input (u8) into output (u32). Assumes len is
     a multiple of 4. */
  static void Decode(u32 *output, u8 *input, u32 len)
  {
    u32 i, j;
  
    for (i = 0, j = 0; j < len; i++, j += 4)
   output[i] = ((u32)input[j]) | (((u32)input[j+1]) << 8) |
     (((u32)input[j+2]) << 16) | (((u32)input[j+3]) << 24);
  }
  