src/crypto/md5-internal.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 "includes.h"
  16
  17 #include "common.h"
  18 #include "md5.h"
  19 #include "md5_i.h"
  20 #include "crypto.h"
  21
  22
  23 static void MD5Transform(u32 buf[4], u32 const in[16]);
  24
  25
  26 typedef struct MD5Context MD5_CTX;
  27
  28
  29 /**
  30  * md5_vector - MD5 hash for data vector
  31  * @num_elem: Number of elements in the data vector
  32  * @addr: Pointers to the data areas
  33  * @len: Lengths of the data blocks
  34  * @mac: Buffer for the hash
  35  * Returns: 0 on success, -1 of failure
  36  */
  37 int md5_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
  38 {
  39         MD5_CTX ctx;
  40         size_t i;
  41
  42         MD5Init(&ctx);
  43         for (i = 0; i < num_elem; i++)
  44                 MD5Update(&ctx, addr[i], len[i]);
  45         MD5Final(mac, &ctx);
  46         return 0;
  47 }
  48
  49
  50 /* ===== start - public domain MD5 implementation ===== */
  51 /*
  52  * This code implements the MD5 message-digest algorithm.
  53  * The algorithm is due to Ron Rivest.  This code was
  54  * written by Colin Plumb in 1993, no copyright is claimed.
  55  * This code is in the public domain; do with it what you wish.
  56  *
  57  * Equivalent code is available from RSA Data Security, Inc.
  58  * This code has been tested against that, and is equivalent,
  59  * except that you don't need to include two pages of legalese
  60  * with every copy.
  61  *
  62  * To compute the message digest of a chunk of bytes, declare an
  63  * MD5Context structure, pass it to MD5Init, call MD5Update as
  64  * needed on buffers full of bytes, and then call MD5Final, which
  65  * will fill a supplied 16-byte array with the digest.
  66  */
  67
  68 #ifndef WORDS_BIGENDIAN
  69 #define byteReverse(buf, len)   /* Nothing */
  70 #else
  71 /*
  72  * Note: this code is harmless on little-endian machines.
  73  */
  74 static void byteReverse(unsigned char *buf, unsigned longs)
  75 {
  76     u32 t;
  77     do {
  78         t = (u32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
  79             ((unsigned) buf[1] << 8 | buf[0]);
  80         *(u32 *) buf = t;
  81         buf += 4;
  82     } while (--longs);
  83 }
  84 #endif
  85
  86 /*
  87  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
  88  * initialization constants.
  89  */
  90 void MD5Init(struct MD5Context *ctx)
  91 {
  92     ctx->buf[0] = 0x67452301;
  93     ctx->buf[1] = 0xefcdab89;
  94     ctx->buf[2] = 0x98badcfe;
  95     ctx->buf[3] = 0x10325476;
  96
  97     ctx->bits[0] = 0;
  98     ctx->bits[1] = 0;
  99 }
 100
 101 /*
 102  * Update context to reflect the concatenation of another buffer full
 103  * of bytes.
 104  */
 105 void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
 106 {
 107     u32 t;
 108
 109     /* Update bitcount */
 110
 111     t = ctx->bits[0];
 112     if ((ctx->bits[0] = t + ((u32) len << 3)) < t)
 113         ctx->bits[1]++;         /* Carry from low to high */
 114     ctx->bits[1] += len >> 29;
 115
 116     t = (t >> 3) & 0x3f;        /* Bytes already in shsInfo->data */
 117
 118     /* Handle any leading odd-sized chunks */
 119
 120     if (t) {
 121         unsigned char *p = (unsigned char *) ctx->in + t;
 122
 123         t = 64 - t;
 124         if (len < t) {
 125             os_memcpy(p, buf, len);
 126             return;
 127         }
 128         os_memcpy(p, buf, t);
 129         byteReverse(ctx->in, 16);
 130         MD5Transform(ctx->buf, (u32 *) ctx->in);
 131         buf += t;
 132         len -= t;
 133     }
 134     /* Process data in 64-byte chunks */
 135
 136     while (len >= 64) {
 137         os_memcpy(ctx->in, buf, 64);
 138         byteReverse(ctx->in, 16);
 139         MD5Transform(ctx->buf, (u32 *) ctx->in);
 140         buf += 64;
 141         len -= 64;
 142     }
 143
 144     /* Handle any remaining bytes of data. */
 145
 146     os_memcpy(ctx->in, buf, len);
 147 }
 148
 149 /*
 150  * Final wrapup - pad to 64-byte boundary with the bit pattern
 151  * 1 0* (64-bit count of bits processed, MSB-first)
 152  */
 153 void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
 154 {
 155     unsigned count;
 156     unsigned char *p;
 157
 158     /* Compute number of bytes mod 64 */
 159     count = (ctx->bits[0] >> 3) & 0x3F;
 160
 161     /* Set the first char of padding to 0x80.  This is safe since there is
 162        always at least one byte free */
 163     p = ctx->in + count;
 164     *p++ = 0x80;
 165
 166     /* Bytes of padding needed to make 64 bytes */
 167     count = 64 - 1 - count;
 168
 169     /* Pad out to 56 mod 64 */
 170     if (count < 8) {
 171         /* Two lots of padding:  Pad the first block to 64 bytes */
 172         os_memset(p, 0, count);
 173         byteReverse(ctx->in, 16);
 174         MD5Transform(ctx->buf, (u32 *) ctx->in);
 175
 176         /* Now fill the next block with 56 bytes */
 177         os_memset(ctx->in, 0, 56);
 178     } else {
 179         /* Pad block to 56 bytes */
 180         os_memset(p, 0, count - 8);
 181     }
 182     byteReverse(ctx->in, 14);
 183
 184     /* Append length in bits and transform */
 185     ((u32 *) ctx->in)[14] = ctx->bits[0];
 186     ((u32 *) ctx->in)[15] = ctx->bits[1];
 187
 188     MD5Transform(ctx->buf, (u32 *) ctx->in);
 189     byteReverse((unsigned char *) ctx->buf, 4);
 190     os_memcpy(digest, ctx->buf, 16);
 191     os_memset(ctx, 0, sizeof(ctx));     /* In case it's sensitive */
 192 }
 193
 194 /* The four core functions - F1 is optimized somewhat */
 195
 196 /* #define F1(x, y, z) (x & y | ~x & z) */
 197 #define F1(x, y, z) (z ^ (x & (y ^ z)))
 198 #define F2(x, y, z) F1(z, x, y)
 199 #define F3(x, y, z) (x ^ y ^ z)
 200 #define F4(x, y, z) (y ^ (x | ~z))
 201
 202 /* This is the central step in the MD5 algorithm. */
 203 #define MD5STEP(f, w, x, y, z, data, s) \
 204         ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
 205
 206 /*
 207  * The core of the MD5 algorithm, this alters an existing MD5 hash to
 208  * reflect the addition of 16 longwords of new data.  MD5Update blocks
 209  * the data and converts bytes into longwords for this routine.
 210  */
 211 static void MD5Transform(u32 buf[4], u32 const in[16])
 212 {
 213     register u32 a, b, c, d;
 214
 215     a = buf[0];
 216     b = buf[1];
 217     c = buf[2];
 218     d = buf[3];
 219
 220     MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
 221     MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
 222     MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
 223     MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
 224     MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
 225     MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
 226     MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
 227     MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
 228     MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
 229     MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
 230     MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 231     MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 232     MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
 233     MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 234     MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 235     MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
 236
 237     MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
 238     MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
 239     MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 240     MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
 241     MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
 242     MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
 243     MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 244     MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
 245     MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
 246     MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
 247     MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
 248     MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
 249     MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
 250     MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
 251     MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
 252     MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 253
 254     MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
 255     MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
 256     MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 257     MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 258     MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
 259     MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
 260     MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
 261     MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 262     MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
 263     MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
 264     MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
 265     MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
 266     MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
 267     MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 268     MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 269     MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
 270
 271     MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
 272     MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
 273     MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 274     MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
 275     MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
 276     MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
 277     MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 278     MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
 279     MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
 280     MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 281     MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
 282     MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 283     MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
 284     MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 285     MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
 286     MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
 287
 288     buf[0] += a;
 289     buf[1] += b;
 290     buf[2] += c;
 291     buf[3] += d;
 292 }
 293 /* ===== end - public domain MD5 implementation ===== */