diplodocus.org Git - nmh/blob - uip/md5.c

   1
   2 /*
   3  * md5.c -- md5 message digest algorithm
   4  *          taken from RFC-1321/Appendix A.3
   5  *
   6  * $Id$
   7  */
   8
   9 /*
  10  * MD5C.C -- RSA Data Security, Inc., MD5 message-digest algorithm
  11  */
  12
  13 /*
  14  * Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
  15  * rights reserved.
  16  *
  17  * License to copy and use this software is granted provided that it
  18  * is identified as the "RSA Data Security, Inc. MD5 Message-Digest
  19  * Algorithm" in all material mentioning or referencing this software
  20  * or this function.
  21  *
  22  * License is also granted to make and use derivative works provided
  23  * that such works are identified as "derived from the RSA Data
  24  * Security, Inc. MD5 Message-Digest Algorithm" in all material
  25  * mentioning or referencing the derived work.
  26  *
  27  * RSA Data Security, Inc. makes no representations concerning either
  28  * the merchantability of this software or the suitability of this
  29  * software for any particular purpose. It is provided "as is"
  30  * without express or implied warranty of any kind.
  31  *
  32  * These notices must be retained in any copies of any part of this
  33  * documentation and/or software.
  34  */
  35
  36 #include <h/md5.h>
  37
  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 void MD5Transform PROTO_LIST ((UINT4 [4], unsigned char [64]));
  59 static void Encode PROTO_LIST ((unsigned char *, UINT4 *, unsigned int));
  60 static void Decode PROTO_LIST ((UINT4 *, unsigned char *, unsigned int));
  61
  62 static unsigned char PADDING[64] = {
  63   0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  64   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  65   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  66 };
  67
  68 /* F, G, H and I are basic MD5 functions.
  69  */
  70 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
  71 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
  72 #define H(x, y, z) ((x) ^ (y) ^ (z))
  73 #define I(x, y, z) ((y) ^ ((x) | (~z)))
  74
  75 /* ROTATE_LEFT rotates x left n bits.
  76  */
  77 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
  78
  79 /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
  80 Rotation is separate from addition to prevent recomputation.
  81  */
  82 #define FF(a, b, c, d, x, s, ac) { \
  83  (a) += F ((b), (c), (d)) + (x) + (UINT4)(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) + (UINT4)(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) + (UINT4)(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) + (UINT4)(ac); \
  99  (a) = ROTATE_LEFT ((a), (s)); \
 100  (a) += (b); \
 101   }
 102
 103 /* MD5 initialization. Begins an MD5 operation, writing a new context.
 104  */
 105 void MD5Init (context)
 106 MD5_CTX *context;                                        /* context */
 107 {
 108   context->count[0] = context->count[1] = 0;
 109   /* Load magic initialization constants.
 110 */
 111   context->state[0] = 0x67452301;
 112   context->state[1] = 0xefcdab89;
 113   context->state[2] = 0x98badcfe;
 114   context->state[3] = 0x10325476;
 115 }
 116
 117 /* MD5 block update operation. Continues an MD5 message-digest
 118   operation, processing another message block, and updating the
 119   context.
 120  */
 121 void MD5Update (context, input, inputLen)
 122 MD5_CTX *context;                                        /* context */
 123 unsigned char *input;                                /* input block */
 124 unsigned int inputLen;                     /* length of input block */
 125 {
 126   unsigned int i, index, partLen;
 127
 128   /* Compute number of bytes mod 64 */
 129   index = (unsigned int)((context->count[0] >> 3) & 0x3F);
 130
 131   /* Update number of bits */
 132   if ((context->count[0] += ((UINT4)inputLen << 3))
 133    < ((UINT4)inputLen << 3))
 134  context->count[1]++;
 135   context->count[1] += ((UINT4)inputLen >> 29);
 136
 137   partLen = 64 - index;
 138
 139   /* Transform as many times as possible. */
 140   if (inputLen >= partLen) {
 141  memcpy ((POINTER)&context->buffer[index], (POINTER)input, partLen);
 142  MD5Transform (context->state, context->buffer);
 143
 144  for (i = partLen; i + 63 < inputLen; i += 64)
 145    MD5Transform (context->state, &input[i]);
 146
 147  index = 0;
 148   }
 149   else
 150  i = 0;
 151
 152   /* Buffer remaining input */
 153   memcpy ((POINTER)&context->buffer[index], (POINTER)&input[i], inputLen-i);
 154 }
 155
 156 /*
 157  * MD5 finalization. Ends an MD5 message-digest operation, writing the
 158  * the message digest and zeroizing the context.
 159  */
 160 void MD5Final (digest, context)
 161 unsigned char digest[16];                         /* message digest */
 162 MD5_CTX *context;                                       /* context */
 163 {
 164   unsigned char bits[8];
 165   unsigned int index, padLen;
 166
 167   /* Save number of bits */
 168   Encode (bits, context->count, 8);
 169
 170   /* Pad out to 56 mod 64.
 171 */
 172   index = (unsigned int)((context->count[0] >> 3) & 0x3f);
 173   padLen = (index < 56) ? (56 - index) : (120 - index);
 174   MD5Update (context, PADDING, padLen);
 175
 176   /* Append length (before padding) */
 177   MD5Update (context, bits, 8);
 178   /* Store state in digest */
 179   Encode (digest, context->state, 16);
 180
 181   /* Zeroize sensitive information. */
 182   memset ((POINTER)context, 0, sizeof(*context));
 183 }
 184
 185 /* MD5 basic transformation. Transforms state based on block.
 186  */
 187 static void MD5Transform (state, block)
 188 UINT4 state[4];
 189 unsigned char block[64];
 190 {
 191   UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
 192
 193   Decode (x, block, 64);
 194
 195   /* Round 1 */
 196   FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
 197   FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
 198   FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
 199   FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
 200   FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
 201   FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
 202   FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
 203   FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
 204   FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
 205   FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
 206   FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
 207   FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
 208   FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
 209   FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
 210   FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
 211   FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
 212
 213  /* Round 2 */
 214   GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
 215   GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
 216   GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
 217   GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
 218   GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
 219   GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
 220   GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
 221   GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
 222   GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
 223   GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
 224   GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
 225   GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
 226   GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
 227   GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
 228   GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
 229   GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
 230
 231   /* Round 3 */
 232   HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
 233   HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
 234   HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
 235   HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
 236   HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
 237   HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
 238   HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
 239   HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
 240   HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
 241   HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
 242   HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
 243   HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
 244   HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
 245   HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
 246   HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
 247   HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
 248
 249   /* Round 4 */
 250   II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
 251   II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
 252   II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
 253   II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
 254   II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
 255   II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
 256   II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
 257   II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
 258   II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
 259   II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
 260   II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
 261   II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
 262   II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
 263   II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
 264   II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
 265   II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
 266
 267   state[0] += a;
 268   state[1] += b;
 269   state[2] += c;
 270   state[3] += d;
 271
 272   /* Zeroize sensitive information. */
 273   memset ((POINTER)x, 0, sizeof(x));
 274 }
 275
 276 /* Encodes input (UINT4) into output (unsigned char). Assumes len is
 277   a multiple of 4.
 278  */
 279 static void Encode (output, input, len)
 280 unsigned char *output;
 281 UINT4 *input;
 282 unsigned int len;
 283 {
 284   unsigned int i, j;
 285
 286   for (i = 0, j = 0; j < len; i++, j += 4) {
 287  output[j] = (unsigned char)(input[i] & 0xff);
 288  output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
 289  output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
 290  output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
 291   }
 292 }
 293
 294 /* Decodes input (unsigned char) into output (UINT4). Assumes len is
 295   a multiple of 4.
 296  */
 297 static void Decode (output, input, len)
 298 UINT4 *output;
 299 unsigned char *input;
 300 unsigned int len;
 301 {
 302   unsigned int i, j;
 303
 304   for (i = 0, j = 0; j < len; i++, j += 4)
 305  output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
 306    (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
 307 }
 308