source/common/md5.cpp

   1 /*****************************************************************************
   2  * md5.cpp: Calculate MD5 for SEI
   3  *****************************************************************************
   4  * Copyright (C) 2011-2012 x265 project
   5  *
   6  * Authors: Min Chen <chenm003@163.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation;
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02111, USA.
  20  *
  21  * This program is also available under a commercial proprietary license.
  22  * For more information, contact us at chenm003@163.com.
  23  *****************************************************************************/
  24
  25 #include "common.h"
  26 #include "md5.h"
  27
  28 namespace x265 {
  29 // private x265 namespace
  30
  31 #ifndef ARCH_BIG_ENDIAN
  32 #define byteReverse(buf, len)   /* Nothing */
  33 #else
  34 static void byteReverse(uint8_t_t *buf, unsigned int nSize)
  35 {
  36     int i;
  37     uint32_t tmp;
  38
  39     for (i = 0; i < nSize; i++)
  40     {
  41         tmp = ((unsigned int)buf[3] << 8 | buf[2]) << 16 |
  42             ((unsigned int)buf[1] << 8 | buf[0]);
  43         *(uint32_t*)buf = tmp;
  44         buf += 4;
  45     }
  46 }
  47
  48 #endif // ifndef ARCH_BIG_ENDIAN
  49
  50 void MD5Transform(uint32_t *buf, uint32_t *in);
  51
  52 /*
  53  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
  54  * initialization constants.
  55  */
  56 void MD5Init(MD5Context *ctx)
  57 {
  58     ctx->buf[0] = 0x67452301;
  59     ctx->buf[1] = 0xefcdab89;
  60     ctx->buf[2] = 0x98badcfe;
  61     ctx->buf[3] = 0x10325476;
  62
  63     ctx->bits[0] = 0;
  64     ctx->bits[1] = 0;
  65 }
  66
  67 /*
  68  * Update context to reflect the concatenation of another buffer full
  69  * of bytes.
  70  */
  71 void MD5Update(MD5Context *ctx, uint8_t *buf, uint32_t len)
  72 {
  73     uint32_t t;
  74
  75     /* Update bitcount */
  76
  77     t = ctx->bits[0];
  78     if ((ctx->bits[0] = t + ((uint32_t)len << 3)) < t)
  79         ctx->bits[1]++; /* Carry from low to high */
  80     ctx->bits[1] += len >> 29;
  81
  82     t = (t >> 3) & 0x3F;        /* Bytes already in shsInfo->data */
  83
  84     /* Handle any leading odd-sized chunks */
  85
  86     if (t)
  87     {
  88         uint8_t *p = (uint8_t*)ctx->in + t;
  89
  90         t = 64 - t;
  91         if (len < t)
  92         {
  93             memcpy(p, buf, len);
  94             return;
  95         }
  96         memcpy(p, buf, t);
  97         byteReverse(ctx->in, 16);
  98         MD5Transform(ctx->buf, (uint32_t*)ctx->in);
  99         buf += t;
 100         len -= t;
 101     }
 102     /* Process data in 64-byte chunks */
 103
 104     while (len >= 64)
 105     {
 106         memcpy(ctx->in, buf, 64);
 107         byteReverse(ctx->in, 16);
 108         MD5Transform(ctx->buf, (uint32_t*)ctx->in);
 109         buf += 64;
 110         len -= 64;
 111     }
 112
 113     /* Handle any remaining bytes of data. */
 114
 115     memcpy(ctx->in, buf, len);
 116 }
 117
 118 /*
 119  * Final wrapup - pad to 64-byte boundary with the bit pattern
 120  * 1 0* (64-bit count of bits processed, MSB-first)
 121  */
 122 void MD5Final(MD5Context *ctx, uint8_t *digest)
 123 {
 124     uint32_t count;
 125     uint8_t  *p;
 126
 127     /* Compute number of bytes mod 64 */
 128     count = (ctx->bits[0] >> 3) & 0x3F;
 129
 130     /* Set the first char of padding to 0x80.  This is safe since there is
 131        always at least one byte free */
 132     p = ctx->in + count;
 133     *p++ = 0x80;
 134
 135     /* Bytes of padding needed to make 64 bytes */
 136     count = 64 - 1 - count;
 137
 138     /* Pad out to 56 mod 64 */
 139     if (count < 8)
 140     {
 141         /* Two lots of padding:  Pad the first block to 64 bytes */
 142         memset(p, 0, count);
 143         byteReverse(ctx->in, 16);
 144         MD5Transform(ctx->buf, (uint32_t*)ctx->in);
 145
 146         /* Now fill the next block with 56 bytes */
 147         memset(ctx->in, 0, 56);
 148     }
 149     else
 150     {
 151         /* Pad block to 56 bytes */
 152         memset(p, 0, count - 8);
 153     }
 154     byteReverse(ctx->in, 14);
 155
 156     /* Append length in bits and transform */
 157     // CHECK_ME: Always use 32-bits operator
 158     uint32_t *table = (uint32_t*)&ctx->in;
 159     table[14] = ctx->bits[0];
 160     table[15] = ctx->bits[1];
 161
 162     MD5Transform(ctx->buf, (uint32_t*)ctx->in);
 163     byteReverse((uint8_t*)ctx->buf, 4);
 164     memcpy(digest, ctx->buf, 16);
 165
 166     memset(ctx, 0, sizeof(*ctx));        /* In case it's sensitive */
 167 }
 168
 169 /* The four core functions - F1 is optimized somewhat */
 170
 171 /* #define F1(x, y, z) (x & y | ~x & z) */
 172 #define F1(x, y, z) (z ^ (x & (y ^ z)))
 173 #define F2(x, y, z) F1(z, x, y)
 174 #define F3(x, y, z) (x ^ y ^ z)
 175 #define F4(x, y, z) (y ^ (x | ~z))
 176
 177 /* This is the central step in the MD5 algorithm. */
 178 #define MD5STEP(f, w, x, y, z, data, s) \
 179     (w += f(x, y, z) + data,  w = w << s | w >> (32 - s),  w += x)
 180
 181 /*
 182  * The core of the MD5 algorithm, this alters an existing MD5 hash to
 183  * reflect the addition of 16 longwords of new data.  MD5Update blocks
 184  * the data and converts bytes into longwords for this routine.
 185  */
 186 void MD5Transform(uint32_t *buf, uint32_t *in)
 187 {
 188     register uint32_t a, b, c, d;
 189
 190     a = buf[0];
 191     b = buf[1];
 192     c = buf[2];
 193     d = buf[3];
 194
 195     MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
 196     MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
 197     MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
 198     MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
 199     MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
 200     MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
 201     MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
 202     MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
 203     MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
 204     MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
 205     MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 206     MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 207     MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
 208     MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 209     MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 210     MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
 211
 212     MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
 213     MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
 214     MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 215     MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
 216     MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
 217     MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
 218     MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 219     MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
 220     MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
 221     MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
 222     MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
 223     MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
 224     MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
 225     MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
 226     MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
 227     MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 228
 229     MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
 230     MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
 231     MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 232     MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 233     MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
 234     MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
 235     MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
 236     MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 237     MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
 238     MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
 239     MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
 240     MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
 241     MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
 242     MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 243     MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 244     MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
 245
 246     MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
 247     MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
 248     MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 249     MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
 250     MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
 251     MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
 252     MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 253     MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
 254     MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
 255     MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 256     MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
 257     MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 258     MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
 259     MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 260     MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
 261     MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
 262
 263     buf[0] += a;
 264     buf[1] += b;
 265     buf[2] += c;
 266     buf[3] += d;
 267 }
 268 }