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