src/lib/crypto/md5.c

   1 /*
   2  * Copyright (c) 2007, Cameron Rich
   3  *
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are met:
   8  *
   9  * * Redistributions of source code must retain the above copyright notice,
  10  *   this list of conditions and the following disclaimer.
  11  * * Redistributions in binary form must reproduce the above copyright notice,
  12  *   this list of conditions and the following disclaimer in the documentation
  13  *   and/or other materials provided with the distribution.
  14  * * Neither the name of the axTLS project nor the names of its contributors
  15  *   may be used to endorse or promote products derived from this software
  16  *   without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  22  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  23  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  24  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  25  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  26  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  27  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  28  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 /**
  32  * This file implements the MD5 algorithm as defined in RFC1321
  33  */
  34
  35 #include <string.h>
  36 #include "os_port.h"
  37 #include "crypto.h"
  38
  39 /* Constants for MD5Transform routine.
  40  */
  41 #define S11 7
  42 #define S12 12
  43 #define S13 17
  44 #define S14 22
  45 #define S21 5
  46 #define S22 9
  47 #define S23 14
  48 #define S24 20
  49 #define S31 4
  50 #define S32 11
  51 #define S33 16
  52 #define S34 23
  53 #define S41 6
  54 #define S42 10
  55 #define S43 15
  56 #define S44 21
  57
  58 /* ----- static functions ----- */
  59 static void MD5Transform(uint32_t state[4], const uint8_t block[64]);
  60 static void Encode(uint8_t *output, uint32_t *input, uint32_t len);
  61 static void Decode(uint32_t *output, const uint8_t *input, uint32_t len);
  62
  63 static const uint8_t PADDING[64] =
  64 {
  65     0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  66     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  67     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  68 };
  69
  70 /* F, G, H and I are basic MD5 functions.
  71  */
  72 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
  73 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
  74 #define H(x, y, z) ((x) ^ (y) ^ (z))
  75 #define I(x, y, z) ((y) ^ ((x) | (~z)))
  76
  77 /* ROTATE_LEFT rotates x left n bits.  */
  78 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
  79
  80 /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
  81    Rotation is separate from addition to prevent recomputation.  */
  82 #define FF(a, b, c, d, x, s, ac) { \
  83     (a) += F ((b), (c), (d)) + (x) + (uint32_t)(ac); \
  84     (a) = ROTATE_LEFT ((a), (s)); \
  85     (a) += (b); \
  86   }
  87 #define GG(a, b, c, d, x, s, ac) { \
  88     (a) += G ((b), (c), (d)) + (x) + (uint32_t)(ac); \
  89     (a) = ROTATE_LEFT ((a), (s)); \
  90     (a) += (b); \
  91   }
  92 #define HH(a, b, c, d, x, s, ac) { \
  93     (a) += H ((b), (c), (d)) + (x) + (uint32_t)(ac); \
  94     (a) = ROTATE_LEFT ((a), (s)); \
  95     (a) += (b); \
  96   }
  97 #define II(a, b, c, d, x, s, ac) { \
  98     (a) += I ((b), (c), (d)) + (x) + (uint32_t)(ac); \
  99     (a) = ROTATE_LEFT ((a), (s)); \
 100     (a) += (b); \
 101   }
 102
 103 /**
 104  * MD5 initialization - begins an MD5 operation, writing a new ctx.
 105  */
 106 EXP_FUNC void STDCALL MD5_Init(MD5_CTX *ctx)
 107 {
 108     ctx->count[0] = ctx->count[1] = 0;
 109
 110     /* Load magic initialization constants.
 111      */
 112     ctx->state[0] = 0x67452301;
 113     ctx->state[1] = 0xefcdab89;
 114     ctx->state[2] = 0x98badcfe;
 115     ctx->state[3] = 0x10325476;
 116 }
 117
 118 /**
 119  * Accepts an array of octets as the next portion of the message.
 120  */
 121 EXP_FUNC void STDCALL MD5_Update(MD5_CTX *ctx, const uint8_t * msg, int len)
 122 {
 123     uint32_t x;
 124     int i, partLen;
 125
 126     /* Compute number of bytes mod 64 */
 127     x = (uint32_t)((ctx->count[0] >> 3) & 0x3F);
 128
 129     /* Update number of bits */
 130     if ((ctx->count[0] += ((uint32_t)len << 3)) < ((uint32_t)len << 3))
 131         ctx->count[1]++;
 132     ctx->count[1] += ((uint32_t)len >> 29);
 133
 134     partLen = 64 - x;
 135
 136     /* Transform as many times as possible.  */
 137     if (len >= partLen)
 138     {
 139         memcpy(&ctx->buffer[x], msg, partLen);
 140         MD5Transform(ctx->state, ctx->buffer);
 141
 142         for (i = partLen; i + 63 < len; i += 64)
 143             MD5Transform(ctx->state, &msg[i]);
 144
 145         x = 0;
 146     }
 147     else
 148         i = 0;
 149
 150     /* Buffer remaining input */
 151     memcpy(&ctx->buffer[x], &msg[i], len-i);
 152 }
 153
 154 /**
 155  * Return the 128-bit message digest into the user's array
 156  */
 157 EXP_FUNC void STDCALL MD5_Final(uint8_t *digest, MD5_CTX *ctx)
 158 {
 159     uint8_t bits[8];
 160     uint32_t x, padLen;
 161
 162     /* Save number of bits */
 163     Encode(bits, ctx->count, 8);
 164
 165     /* Pad out to 56 mod 64.
 166      */
 167     x = (uint32_t)((ctx->count[0] >> 3) & 0x3f);
 168     padLen = (x < 56) ? (56 - x) : (120 - x);
 169     MD5_Update(ctx, PADDING, padLen);
 170
 171     /* Append length (before padding) */
 172     MD5_Update(ctx, bits, 8);
 173
 174     /* Store state in digest */
 175     Encode(digest, ctx->state, MD5_SIZE);
 176 }
 177
 178 /**
 179  * MD5 basic transformation. Transforms state based on block.
 180  */
 181 static void MD5Transform(uint32_t state[4], const uint8_t block[64])
 182 {
 183     uint32_t a = state[0], b = state[1], c = state[2],
 184              d = state[3], x[MD5_SIZE];
 185
 186     Decode(x, block, 64);
 187
 188     /* Round 1 */
 189     FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
 190     FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
 191     FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
 192     FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
 193     FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
 194     FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
 195     FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
 196     FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
 197     FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
 198     FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
 199     FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
 200     FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
 201     FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
 202     FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
 203     FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
 204     FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
 205
 206     /* Round 2 */
 207     GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
 208     GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
 209     GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
 210     GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
 211     GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
 212     GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
 213     GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
 214     GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
 215     GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
 216     GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
 217     GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
 218     GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
 219     GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
 220     GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
 221     GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
 222     GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
 223
 224     /* Round 3 */
 225     HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
 226     HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
 227     HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
 228     HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
 229     HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
 230     HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
 231     HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
 232     HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
 233     HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
 234     HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
 235     HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
 236     HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
 237     HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
 238     HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
 239     HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
 240     HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
 241
 242     /* Round 4 */
 243     II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
 244     II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
 245     II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
 246     II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
 247     II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
 248     II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
 249     II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
 250     II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
 251     II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
 252     II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
 253     II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
 254     II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
 255     II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
 256     II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
 257     II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
 258     II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
 259
 260     state[0] += a;
 261     state[1] += b;
 262     state[2] += c;
 263     state[3] += d;
 264 }
 265
 266 /**
 267  * Encodes input (uint32_t) into output (uint8_t). Assumes len is
 268  *   a multiple of 4.
 269  */
 270 static void Encode(uint8_t *output, uint32_t *input, uint32_t len)
 271 {
 272     uint32_t i, j;
 273
 274     for (i = 0, j = 0; j < len; i++, j += 4)
 275     {
 276         output[j] = (uint8_t)(input[i] & 0xff);
 277         output[j+1] = (uint8_t)((input[i] >> 8) & 0xff);
 278         output[j+2] = (uint8_t)((input[i] >> 16) & 0xff);
 279         output[j+3] = (uint8_t)((input[i] >> 24) & 0xff);
 280     }
 281 }
 282
 283 /**
 284  *  Decodes input (uint8_t) into output (uint32_t). Assumes len is
 285  *   a multiple of 4.
 286  */
 287 static void Decode(uint32_t *output, const uint8_t *input, uint32_t len)
 288 {
 289     uint32_t i, j;
 290
 291     for (i = 0, j = 0; j < len; i++, j += 4)
 292         output[i] = ((uint32_t)input[j]) | (((uint32_t)input[j+1]) << 8) |
 293             (((uint32_t)input[j+2]) << 16) | (((uint32_t)input[j+3]) << 24);
 294 }