wsutil/md5.c

   1 /* $Id$ */
   2 /*
   3  * Copyright (C) 2003-2006 Benny Prijono <benny@prijono.org>
   4  * Copyright (C) 2012      C Elston, Katalix Systems Ltd <celston@katalix.com>
   5  *
   6  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  * Copyright 1998 Gerald Combs
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  23  *
  24  *  2012-08-21 - C Elston - Split md5_hmac function to allow incremental usage.
  25  *
  26  */
  27
  28
  29 #include "config.h"
  30
  31 #include <glib.h>
  32 #include <string.h>
  33
  34 #include "pint.h"
  35 #include "md5.h"
  36 /*
  37  * This code implements the MD5 message-digest algorithm.
  38  * The algorithm is due to Ron Rivest.  This code was
  39  * written by Colin Plumb in 1993, no copyright is claimed.
  40  * This code is in the public domain; do with it what you wish.
  41  *
  42  * Equivalent code is available from RSA Data Security, Inc.
  43  * This code has been tested against that, and is equivalent,
  44  * except that you don't need to include two pages of legalese
  45  * with every copy.
  46  *
  47  * To compute the message digest of a chunk of bytes, declare an
  48  * MD5Context structure, pass it to MD5Init, call MD5Update as
  49  * needed on buffers full of bytes, and then call MD5Final, which
  50  * will fill a supplied 16-byte array with the digest.
  51  */
  52
  53 #if WORDS_BIGENDIAN == 1
  54 #define HIGHFIRST 1
  55 #endif
  56
  57 #ifndef HIGHFIRST
  58 #define byteReverse(buf, len)   /* Nothing */
  59 #else
  60 /*
  61  * Note: this code is harmless on little-endian machines.
  62  */
  63 static void byteReverse(guint32 *buf, unsigned longs)
  64 {
  65     guint32 t;
  66     do {
  67         t = pletohl(buf);
  68         *buf = t;
  69         buf++;
  70     } while (--longs);
  71 }
  72 #endif
  73
  74 static void MD5Transform(guint32 buf[4], guint32 const in[16]);
  75
  76
  77 /*
  78  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
  79  * initialization constants.
  80  */
  81 void md5_init(md5_state_t *ctx)
  82 {
  83     ctx->buf[0] = 0x67452301;
  84     ctx->buf[1] = 0xefcdab89;
  85     ctx->buf[2] = 0x98badcfe;
  86     ctx->buf[3] = 0x10325476;
  87
  88     ctx->bits[0] = 0;
  89     ctx->bits[1] = 0;
  90 }
  91
  92 /*
  93  * Update context to reflect the concatenation of another buffer full
  94  * of bytes.
  95  */
  96 void md5_append( md5_state_t *ctx, unsigned char const *buf, size_t len)
  97 {
  98     guint32 t;
  99
 100     /* Update bitcount */
 101
 102     t = ctx->bits[0];
 103     if ((ctx->bits[0] = t + ((guint32) len << 3)) < t)
 104         ctx->bits[1]++;         /* Carry from low to high */
 105     ctx->bits[1] += (guint32) len >> 29;
 106
 107     t = (t >> 3) & 0x3f;        /* Bytes already in shsInfo->data */
 108
 109     /* Handle any leading odd-sized chunks */
 110
 111     if (t) {
 112         unsigned char *p = (unsigned char *) ctx->in + t;
 113
 114         t = 64 - t;
 115         if (len < t) {
 116             memcpy(p, buf, len);
 117             return;
 118         }
 119         memcpy(p, buf, t);
 120         byteReverse(ctx->in, 16);
 121         MD5Transform(ctx->buf, ctx->in);
 122         buf += t;
 123         len -= t;
 124     }
 125     /* Process data in 64-byte chunks */
 126
 127     while (len >= 64) {
 128         memcpy(ctx->in, buf, 64);
 129         byteReverse(ctx->in, 16);
 130         MD5Transform(ctx->buf, ctx->in);
 131         buf += 64;
 132         len -= 64;
 133     }
 134
 135     /* Handle any remaining bytes of data. */
 136
 137     memcpy(ctx->in, buf, len);
 138 }
 139
 140 /*
 141  * Final wrapup - pad to 64-byte boundary with the bit pattern
 142  * 1 0* (64-bit count of bits processed, MSB-first)
 143  */
 144 void md5_finish(md5_state_t *ctx, unsigned char digest[16])
 145 {
 146     guint count;
 147     unsigned char *p;
 148
 149     /* Compute number of bytes mod 64 */
 150     count = (ctx->bits[0] >> 3) & 0x3F;
 151
 152     /* Set the first char of padding to 0x80.  This is safe since there is
 153        always at least one byte free */
 154     p = (unsigned char *) ctx->in + count;
 155     *p++ = 0x80;
 156
 157     /* Bytes of padding needed to make 64 bytes */
 158     count = 64 - 1 - count;
 159
 160     /* Pad out to 56 mod 64 */
 161     if (count < 8) {
 162         /* Two lots of padding:  Pad the first block to 64 bytes */
 163         memset(p, 0, count);
 164         byteReverse(ctx->in, 16);
 165         MD5Transform(ctx->buf, ctx->in);
 166
 167         /* Now fill the next block with 56 bytes */
 168         memset(ctx->in, 0, 56);
 169     } else {
 170         /* Pad block to 56 bytes */
 171         memset(p, 0, count - 8);
 172     }
 173     byteReverse(ctx->in, 14);
 174
 175     /* Append length in bits and transform */
 176     ctx->in[14] = ctx->bits[0];
 177     ctx->in[15] = ctx->bits[1];
 178
 179     MD5Transform(ctx->buf, ctx->in);
 180     byteReverse(ctx->buf, 4);
 181     memcpy(digest, ctx->buf, 16);
 182     memset(ctx, 0, sizeof(md5_state_t));        /* In case it's sensitive */
 183 }
 184
 185 /* The four core functions - F1 is optimized somewhat */
 186
 187 /* #define F1(x, y, z) (x & y | ~x & z) */
 188 #define F1(x, y, z) (z ^ (x & (y ^ z)))
 189 #define F2(x, y, z) F1(z, x, y)
 190 #define F3(x, y, z) (x ^ y ^ z)
 191 #define F4(x, y, z) (y ^ (x | ~z))
 192
 193 /* This is the central step in the MD5 algorithm. */
 194 #define MD5STEP(f, w, x, y, z, data, s) \
 195         ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
 196
 197 /*
 198  * The core of the MD5 algorithm, this alters an existing MD5 hash to
 199  * reflect the addition of 16 longwords of new data.  MD5Update blocks
 200  * the data and converts bytes into longwords for this routine.
 201  */
 202 static void MD5Transform(guint32 buf[4], guint32 const in[16])
 203 {
 204     register guint32 a, b, c, d;
 205
 206     a = buf[0];
 207     b = buf[1];
 208     c = buf[2];
 209     d = buf[3];
 210
 211     MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
 212     MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
 213     MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
 214     MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
 215     MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
 216     MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
 217     MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
 218     MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
 219     MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
 220     MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
 221     MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 222     MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 223     MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
 224     MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 225     MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 226     MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
 227
 228     MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
 229     MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
 230     MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 231     MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
 232     MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
 233     MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
 234     MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 235     MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
 236     MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
 237     MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
 238     MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
 239     MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
 240     MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
 241     MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
 242     MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
 243     MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 244
 245     MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
 246     MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
 247     MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 248     MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 249     MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
 250     MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
 251     MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
 252     MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 253     MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
 254     MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
 255     MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
 256     MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
 257     MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
 258     MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 259     MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 260     MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
 261
 262     MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
 263     MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
 264     MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 265     MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
 266     MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
 267     MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
 268     MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 269     MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
 270     MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
 271     MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 272     MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
 273     MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 274     MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
 275     MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 276     MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
 277     MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
 278
 279     buf[0] += a;
 280     buf[1] += b;
 281     buf[2] += c;
 282     buf[3] += d;
 283 }
 284
 285 /* from RFC 2104 HMAC  Appendix -- Sample Code */
 286
 287 void md5_hmac_init(md5_hmac_state_t *hctx, const guint8* key, size_t key_len)
 288 {
 289     guint8 k_ipad[65];    /* inner padding - * key XORd with ipad */
 290     guint8 tk[16];
 291     int i;
 292
 293     /* if key is longer than 64 bytes reset it to key=MD5(key) */
 294     if (key_len > 64) {
 295         md5_state_t tctx;
 296
 297         md5_init(&tctx);
 298         md5_append(&tctx, key, key_len);
 299         md5_finish(&tctx, tk);
 300
 301         key = tk;
 302         key_len = 16;
 303     }
 304
 305     /*
 306      * the HMAC_MD5 transform looks like:
 307      *
 308      * MD5(K XOR opad, MD5(K XOR ipad, text))
 309      *
 310      * where K is an n byte key
 311      * ipad is the byte 0x36 repeated 64 times
 312      * opad is the byte 0x5c repeated 64 times
 313      * and text is the data being protected
 314      */
 315
 316     /* start out by storing key in pads */
 317     memset(k_ipad, 0, sizeof(k_ipad));
 318     memset(hctx->k_opad, 0, sizeof(hctx->k_opad));
 319     memcpy(k_ipad, key, key_len);
 320     memcpy(hctx->k_opad, key, key_len);
 321
 322     /* XOR key with ipad and opad values */
 323     for (i=0; i<64; i++) {
 324         k_ipad[i] ^= 0x36;
 325         hctx->k_opad[i] ^= 0x5c;
 326     }
 327
 328     /*
 329      * perform inner MD5
 330      */
 331     md5_init(&hctx->ctx);                   /* init context for 1st  pass */
 332     md5_append(&hctx->ctx, k_ipad, 64);     /* start with inner pad */
 333 }
 334
 335 void md5_hmac_append(md5_hmac_state_t *hctx, const guint8* text, size_t text_len)
 336 {
 337     md5_append(&hctx->ctx, text, text_len);
 338 }
 339
 340 void md5_hmac_finish(md5_hmac_state_t *hctx, guint8 digest[16])
 341 {
 342     md5_state_t context;
 343
 344     md5_finish(&hctx->ctx, digest);          /* finish up 1st pass */
 345
 346     /*
 347      * perform outer MD5
 348      */
 349     md5_init(&context);                     /* init context for 2nd pass */
 350     md5_append(&context, hctx->k_opad, 64); /* start with outer pad */
 351     md5_append(&context, digest, 16);       /* then results of 1st hash */
 352     md5_finish(&context, digest);           /* finish up 2nd pass */
 353 }
 354
 355 void md5_hmac(const guint8* text, size_t text_len, const guint8* key, size_t key_len, guint8 digest[16])
 356 {
 357     md5_hmac_state_t hctx;
 358
 359     md5_hmac_init(&hctx, key, key_len);
 360     md5_hmac_append(&hctx, text, text_len);
 361     md5_hmac_finish(&hctx, digest);
 362 }