pppmd5.c

来自「用于嵌入式系统的TCP/IP协议栈」· C语言 代码 · 共 384 行 · 第 1/2 页

  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, 0x02441453); /* 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, 0x04881D05); /* 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(x, 0, sizeof(x));
}

/***********************************************************************/
/* Global Function Definitions                                         */
/***********************************************************************/

/***********************************************************************/
/*     MD5Init: MD5 initialization. Begins an MD5 operation, writing a */
/*              new context.                                           */
/*                                                                     */
/*       Input: context = points to MD5 context data                   */
/*                                                                     */
/***********************************************************************/
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;
}

/***********************************************************************/
/*   MD5Update: MD5 block update operation. Continues an MD5 message-  */
/*              digest operation, processing another message block,    */
/*              and updating the context.                              */
/*                                                                     */
/*      Inputs: context = points to MD5 context data                   */
/*              input = input block                                    */
/*              inputLen = length of input block                       */
/*                                                                     */
/***********************************************************************/
void MD5Update(MD5_CTX *context, const ui8 *input, ui32 inputLen)
{
  uint i, index, partLen;

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

  /*-------------------------------------------------------------------*/
  /* Update number of bits.                                            */
  /*-------------------------------------------------------------------*/
  if ((context->count[0] += (inputLen << 3)) < (inputLen << 3))
    context->count[1]++;
  context->count[1] += (inputLen >> 29);
  partLen = 64 - index;

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

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

    index = 0;
  }
  else
    i = 0;

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

/***********************************************************************/
/*    MD5Final: Finalization. Ends a message-digest operation, writing */
/*              the message digest and zeroizing the context.          */
/*                                                                     */
/*      Inputs: digest = message digest                                */
/*              context = points to MD5 context data                   */
/*                                                                     */
/***********************************************************************/
void MD5Final(ui8 digest[16], MD5_CTX *context)
{
  ui8 bits[8];
  uint index, padLen;

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

  /*-------------------------------------------------------------------*/
  /* Pad out to 56 mod 64.                                             */
  /*-------------------------------------------------------------------*/
  index = (uint)((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.                                    */
  /*-------------------------------------------------------------------*/
  memset(context, 0, sizeof(*context));
}