stun/md5.c

   1 /*
   2  * MD5 hash implementation and interface functions
   3  * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "md5.h"
  16 #include <string.h>
  17
  18 /* ===== start - public domain MD5 implementation ===== */
  19 /*
  20  * This code implements the MD5 message-digest algorithm.
  21  * The algorithm is due to Ron Rivest.  This code was
  22  * written by Colin Plumb in 1993, no copyright is claimed.
  23  * This code is in the public domain; do with it what you wish.
  24  *
  25  * Equivalent code is available from RSA Data Security, Inc.
  26  * This code has been tested against that, and is equivalent,
  27  * except that you don't need to include two pages of legalese
  28  * with every copy.
  29  *
  30  * To compute the message digest of a chunk of bytes, declare an
  31  * MD5Context structure, pass it to MD5Init, call MD5Update as
  32  * needed on buffers full of bytes, and then call MD5Final, which
  33  * will fill a supplied 16-byte array with the digest.
  34  */
  35
  36 static void MD5Transform(uint32_t buf[4], uint32_t const in[16]);
  37
  38 static int am_big_endian(void)
  39 {
  40   long one= 1;
  41   return !(*((char *)(&one)));
  42 }
  43
  44 /*
  45  * Note: this code is harmless on little-endian machines.
  46  */
  47 static void byteReverse(unsigned char *buf, unsigned longs)
  48 {
  49   uint32_t t;
  50   if (am_big_endian ()) {
  51     do {
  52       t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
  53           ((unsigned) buf[1] << 8 | buf[0]);
  54       *(uint32_t *) buf = t;
  55       buf += 4;
  56     } while (--longs);
  57   }
  58 }
  59
  60 /*
  61  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
  62  * initialization constants.
  63  */
  64 void MD5Init(MD5_CTX *ctx)
  65 {
  66   ctx->buf[0] = 0x67452301;
  67   ctx->buf[1] = 0xefcdab89;
  68   ctx->buf[2] = 0x98badcfe;
  69   ctx->buf[3] = 0x10325476;
  70
  71   ctx->bits[0] = 0;
  72   ctx->bits[1] = 0;
  73 }
  74
  75 /*
  76  * Update context to reflect the concatenation of another buffer full
  77  * of bytes.
  78  */
  79 void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
  80 {
  81   uint32_t t;
  82
  83   /* Update bitcount */
  84
  85   t = ctx->bits[0];
  86   if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t)
  87     ctx->bits[1]++;             /* Carry from low to high */
  88   ctx->bits[1] += len >> 29;
  89
  90   t = (t >> 3) & 0x3f;  /* Bytes already in shsInfo->data */
  91
  92   /* Handle any leading odd-sized chunks */
  93
  94   if (t) {
  95     unsigned char *p = (unsigned char *) ctx->in + t;
  96
  97     t = 64 - t;
  98     if (len < t) {
  99       memcpy(p, buf, len);
 100       return;
 101     }
 102     memcpy(p, buf, t);
 103     byteReverse(ctx->in, 16);
 104     MD5Transform(ctx->buf, (uint32_t *) ctx->in);
 105     buf += t;
 106     len -= t;
 107   }
 108   /* Process data in 64-byte chunks */
 109
 110   while (len >= 64) {
 111     memcpy(ctx->in, buf, 64);
 112     byteReverse(ctx->in, 16);
 113     MD5Transform(ctx->buf, (uint32_t *) ctx->in);
 114     buf += 64;
 115     len -= 64;
 116   }
 117
 118   /* Handle any remaining bytes of data. */
 119
 120   memcpy(ctx->in, buf, len);
 121 }
 122
 123 /*
 124  * Final wrapup - pad to 64-byte boundary with the bit pattern
 125  * 1 0* (64-bit count of bits processed, MSB-first)
 126  */
 127 void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
 128 {
 129   unsigned count;
 130   unsigned char *p;
 131
 132   /* Compute number of bytes mod 64 */
 133   count = (ctx->bits[0] >> 3) & 0x3F;
 134
 135   /* Set the first char of padding to 0x80.  This is safe since there is
 136      always at least one byte free */
 137   p = ctx->in + count;
 138   *p++ = 0x80;
 139
 140   /* Bytes of padding needed to make 64 bytes */
 141   count = 64 - 1 - count;
 142
 143   /* Pad out to 56 mod 64 */
 144   if (count < 8) {
 145     /* Two lots of padding:  Pad the first block to 64 bytes */
 146     memset(p, 0, count);
 147     byteReverse(ctx->in, 16);
 148     MD5Transform(ctx->buf, (uint32_t *) ctx->in);
 149
 150     /* Now fill the next block with 56 bytes */
 151     memset(ctx->in, 0, 56);
 152   } else {
 153     /* Pad block to 56 bytes */
 154     memset(p, 0, count - 8);
 155   }
 156   byteReverse(ctx->in, 14);
 157
 158   /* Append length in bits and transform */
 159   ((uint32_t *) ctx->in)[14] = ctx->bits[0];
 160   ((uint32_t *) ctx->in)[15] = ctx->bits[1];
 161
 162   MD5Transform(ctx->buf, (uint32_t *) ctx->in);
 163   byteReverse((unsigned char *) ctx->buf, 4);
 164   memcpy(digest, ctx->buf, 16);
 165   memset(ctx, 0, sizeof(ctx));  /* In case it's sensitive */
 166 }
 167
 168 /* The four core functions - F1 is optimized somewhat */
 169
 170 /* #define F1(x, y, z) (x & y | ~x & z) */
 171 #define F1(x, y, z) (z ^ (x & (y ^ z)))
 172 #define F2(x, y, z) F1(z, x, y)
 173 #define F3(x, y, z) (x ^ y ^ z)
 174 #define F4(x, y, z) (y ^ (x | ~z))
 175
 176 /* This is the central step in the MD5 algorithm. */
 177 #define MD5STEP(f, w, x, y, z, data, s) \
 178         ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
 179
 180 /*
 181  * The core of the MD5 algorithm, this alters an existing MD5 hash to
 182  * reflect the addition of 16 longwords of new data.  MD5Update blocks
 183  * the data and converts bytes into longwords for this routine.
 184  */
 185 static void MD5Transform(uint32_t buf[4], uint32_t const in[16])
 186 {
 187   register uint32_t a, b, c, d;
 188
 189   a = buf[0];
 190   b = buf[1];
 191   c = buf[2];
 192   d = buf[3];
 193
 194   MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
 195   MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
 196   MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
 197   MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
 198   MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
 199   MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
 200   MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
 201   MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
 202   MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
 203   MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
 204   MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 205   MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 206   MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
 207   MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 208   MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 209   MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
 210
 211   MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
 212   MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
 213   MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 214   MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
 215   MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
 216   MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
 217   MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 218   MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
 219   MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
 220   MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
 221   MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
 222   MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
 223   MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
 224   MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
 225   MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
 226   MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 227
 228   MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
 229   MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
 230   MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 231   MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 232   MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
 233   MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
 234   MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
 235   MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 236   MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
 237   MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
 238   MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
 239   MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
 240   MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
 241   MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 242   MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 243   MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
 244
 245   MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
 246   MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
 247   MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 248   MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
 249   MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
 250   MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
 251   MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 252   MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
 253   MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
 254   MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 255   MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
 256   MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 257   MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
 258   MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 259   MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
 260   MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
 261
 262   buf[0] += a;
 263   buf[1] += b;
 264   buf[2] += c;
 265   buf[3] += d;
 266 }
 267 /* ===== end - public domain MD5 implementation ===== */