release/src/router/rp-l2tp/md5.c

   1 /*
   2  * This code implements the MD5 message-digest algorithm.
   3  * The algorithm is due to Ron Rivest.  This code was
   4  * written by Colin Plumb in 1993, no copyright is claimed.
   5  * This code is in the public domain; do with it what you wish.
   6  *
   7  * Equivalent code is available from RSA Data Security, Inc.
   8  * This code has been tested against that, and is equivalent,
   9  * except that you don't need to include two pages of legalese
  10  * with every copy.
  11  *
  12  * To compute the message digest of a chunk of bytes, declare an
  13  * MD5Context structure, pass it to MD5Init, call MD5Update as
  14  * needed on buffers full of bytes, and then call MD5Final, which
  15  * will fill a supplied 16-byte array with the digest.
  16  * LIC: GPL
  17  *
  18  */
  19 #include <string.h>             /* for memcpy() */
  20 #include "md5.h"
  21
  22 void byteReverse(unsigned char *buf, unsigned longs);
  23
  24 /*
  25  * Note: this code is harmless on little-endian machines.
  26  */
  27 void byteReverse(unsigned char *buf, unsigned longs)
  28 {
  29     uint32 t;
  30     do {
  31         t = (uint32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
  32             ((unsigned) buf[1] << 8 | buf[0]);
  33         *(uint32 *) buf = t;
  34         buf += 4;
  35     } while (--longs);
  36 }
  37
  38 /*
  39  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
  40  * initialization constants.
  41  */
  42 void MD5Init(struct MD5Context *ctx)
  43 {
  44     ctx->buf[0] = 0x67452301;
  45     ctx->buf[1] = 0xefcdab89;
  46     ctx->buf[2] = 0x98badcfe;
  47     ctx->buf[3] = 0x10325476;
  48
  49     ctx->bits[0] = 0;
  50     ctx->bits[1] = 0;
  51 }
  52
  53 /*
  54  * Update context to reflect the concatenation of another buffer full
  55  * of bytes.
  56  */
  57 void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
  58 {
  59     uint32 t;
  60
  61     /* Update bitcount */
  62
  63     t = ctx->bits[0];
  64     if ((ctx->bits[0] = t + ((uint32) len << 3)) < t)
  65         ctx->bits[1]++;         /* Carry from low to high */
  66     ctx->bits[1] += len >> 29;
  67
  68     t = (t >> 3) & 0x3f;        /* Bytes already in shsInfo->data */
  69
  70     /* Handle any leading odd-sized chunks */
  71
  72     if (t) {
  73         unsigned char *p = (unsigned char *) ctx->in + t;
  74
  75         t = 64 - t;
  76         if (len < t) {
  77             memcpy(p, buf, len);
  78             return;
  79         }
  80         memcpy(p, buf, t);
  81         byteReverse(ctx->in, 16);
  82         MD5Transform(ctx->buf, (uint32 *) ctx->in);
  83         buf += t;
  84         len -= t;
  85     }
  86     /* Process data in 64-byte chunks */
  87
  88     while (len >= 64) {
  89         memcpy(ctx->in, buf, 64);
  90         byteReverse(ctx->in, 16);
  91         MD5Transform(ctx->buf, (uint32 *) ctx->in);
  92         buf += 64;
  93         len -= 64;
  94     }
  95
  96     /* Handle any remaining bytes of data. */
  97
  98     memcpy(ctx->in, buf, len);
  99 }
 100
 101 /*
 102  * Final wrapup - pad to 64-byte boundary with the bit pattern
 103  * 1 0* (64-bit count of bits processed, MSB-first)
 104  */
 105 void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
 106 {
 107     unsigned count;
 108     unsigned char *p;
 109
 110     /* Compute number of bytes mod 64 */
 111     count = (ctx->bits[0] >> 3) & 0x3F;
 112
 113     /* Set the first char of padding to 0x80.  This is safe since there is
 114        always at least one byte free */
 115     p = ctx->in + count;
 116     *p++ = 0x80;
 117
 118     /* Bytes of padding needed to make 64 bytes */
 119     count = 64 - 1 - count;
 120
 121     /* Pad out to 56 mod 64 */
 122     if (count < 8) {
 123         /* Two lots of padding:  Pad the first block to 64 bytes */
 124         memset(p, 0, count);
 125         byteReverse(ctx->in, 16);
 126         MD5Transform(ctx->buf, (uint32 *) ctx->in);
 127
 128         /* Now fill the next block with 56 bytes */
 129         memset(ctx->in, 0, 56);
 130     } else {
 131         /* Pad block to 56 bytes */
 132         memset(p, 0, count - 8);
 133     }
 134     byteReverse(ctx->in, 14);
 135
 136     /* Append length in bits and transform */
 137     ((uint32 *) ctx->in)[14] = ctx->bits[0];
 138     ((uint32 *) ctx->in)[15] = ctx->bits[1];
 139
 140     MD5Transform(ctx->buf, (uint32 *) ctx->in);
 141     byteReverse((unsigned char *) ctx->buf, 4);
 142     memcpy(digest, ctx->buf, 16);
 143     memset(ctx, 0, sizeof(ctx));        /* In case it's sensitive */
 144 }
 145
 146 #ifndef ASM_MD5
 147
 148 /* The four core functions - F1 is optimized somewhat */
 149
 150 /* #define F1(x, y, z) (x & y | ~x & z) */
 151 #define F1(x, y, z) (z ^ (x & (y ^ z)))
 152 #define F2(x, y, z) F1(z, x, y)
 153 #define F3(x, y, z) (x ^ y ^ z)
 154 #define F4(x, y, z) (y ^ (x | ~z))
 155
 156 /* This is the central step in the MD5 algorithm. */
 157 #define MD5STEP(f, w, x, y, z, data, s) \
 158         ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
 159
 160 /*
 161  * The core of the MD5 algorithm, this alters an existing MD5 hash to
 162  * reflect the addition of 16 longwords of new data.  MD5Update blocks
 163  * the data and converts bytes into longwords for this routine.
 164  */
 165 void MD5Transform(uint32 buf[4], uint32 const in[16])
 166 {
 167     register uint32 a, b, c, d;
 168
 169     a = buf[0];
 170     b = buf[1];
 171     c = buf[2];
 172     d = buf[3];
 173
 174     MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
 175     MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
 176     MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
 177     MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
 178     MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
 179     MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
 180     MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
 181     MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
 182     MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
 183     MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
 184     MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 185     MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 186     MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
 187     MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 188     MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 189     MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
 190
 191     MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
 192     MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
 193     MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 194     MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
 195     MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
 196     MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
 197     MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 198     MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
 199     MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
 200     MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
 201     MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
 202     MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
 203     MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
 204     MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
 205     MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
 206     MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 207
 208     MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
 209     MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
 210     MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 211     MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 212     MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
 213     MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
 214     MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
 215     MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 216     MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
 217     MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
 218     MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
 219     MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
 220     MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
 221     MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 222     MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 223     MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
 224
 225     MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
 226     MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
 227     MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 228     MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
 229     MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
 230     MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
 231     MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 232     MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
 233     MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
 234     MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 235     MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
 236     MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 237     MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
 238     MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 239     MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
 240     MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
 241
 242     buf[0] += a;
 243     buf[1] += b;
 244     buf[2] += c;
 245     buf[3] += d;
 246 }
 247
 248 #endif