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   1 /* md5.c -- md5 message digest algorithm
   2  *          taken from RFC-1321/Appendix A.3
   3  */
   4
   5 /*
   6  * MD5C.C -- RSA Data Security, Inc., MD5 message-digest algorithm
   7  */
   8
   9 /*
  10  * Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
  11  * rights reserved.
  12  *
  13  * License to copy and use this software is granted provided that it
  14  * is identified as the "RSA Data Security, Inc. MD5 Message-Digest
  15  * Algorithm" in all material mentioning or referencing this software
  16  * or this function.
  17  *
  18  * License is also granted to make and use derivative works provided
  19  * that such works are identified as "derived from the RSA Data
  20  * Security, Inc. MD5 Message-Digest Algorithm" in all material
  21  * mentioning or referencing the derived work.
  22  *
  23  * RSA Data Security, Inc. makes no representations concerning either
  24  * the merchantability of this software or the suitability of this
  25  * software for any particular purpose. It is provided "as is"
  26  * without express or implied warranty of any kind.
  27  *
  28  * These notices must be retained in any copies of any part of this
  29  * documentation and/or software.
  30  */
  31
  32 #include <h/md5.h>
  33
  34 /*
  35  * Constants for MD5Transform routine.
  36  */
  37 #define S11 7
  38 #define S12 12
  39 #define S13 17
  40 #define S14 22
  41 #define S21 5
  42 #define S22 9
  43 #define S23 14
  44 #define S24 20
  45 #define S31 4
  46 #define S32 11
  47 #define S33 16
  48 #define S34 23
  49 #define S41 6
  50 #define S42 10
  51 #define S43 15
  52 #define S44 21
  53
  54 static void MD5Transform PROTO_LIST ((UINT4 [4], unsigned char [64]));
  55 static void Encode PROTO_LIST ((unsigned char *, UINT4 *, unsigned int));
  56 static void Decode PROTO_LIST ((UINT4 *, unsigned char *, unsigned int));
  57
  58 static unsigned char PADDING[64] = {
  59   0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  60   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  61   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  62 };
  63
  64 /* F, G, H and I are basic MD5 functions.
  65  */
  66 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
  67 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
  68 #define H(x, y, z) ((x) ^ (y) ^ (z))
  69 #define I(x, y, z) ((y) ^ ((x) | (~z)))
  70
  71 /* ROTATE_LEFT rotates x left n bits.
  72  */
  73 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
  74
  75 /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
  76 Rotation is separate from addition to prevent recomputation.
  77  */
  78 #define FF(a, b, c, d, x, s, ac) { \
  79  (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
  80  (a) = ROTATE_LEFT ((a), (s)); \
  81  (a) += (b); \
  82   }
  83 #define GG(a, b, c, d, x, s, ac) { \
  84  (a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
  85  (a) = ROTATE_LEFT ((a), (s)); \
  86  (a) += (b); \
  87   }
  88 #define HH(a, b, c, d, x, s, ac) { \
  89  (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
  90  (a) = ROTATE_LEFT ((a), (s)); \
  91  (a) += (b); \
  92   }
  93 #define II(a, b, c, d, x, s, ac) { \
  94  (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
  95  (a) = ROTATE_LEFT ((a), (s)); \
  96  (a) += (b); \
  97   }
  98
  99 /* MD5 initialization. Begins an MD5 operation, writing a new context.
 100  */
 101 void MD5Init (context)
 102 MD5_CTX *context;                                        /* context */
 103 {
 104   context->count[0] = context->count[1] = 0;
 105   /* Load magic initialization constants.
 106 */
 107   context->state[0] = 0x67452301;
 108   context->state[1] = 0xefcdab89;
 109   context->state[2] = 0x98badcfe;
 110   context->state[3] = 0x10325476;
 111 }
 112
 113 /* MD5 block update operation. Continues an MD5 message-digest
 114   operation, processing another message block, and updating the
 115   context.
 116  */
 117 void MD5Update (context, input, inputLen)
 118 MD5_CTX *context;                                        /* context */
 119 unsigned char *input;                                /* input block */
 120 unsigned int inputLen;                     /* length of input block */
 121 {
 122   unsigned int i, index, partLen;
 123
 124   /* Compute number of bytes mod 64 */
 125   index = (unsigned int)((context->count[0] >> 3) & 0x3F);
 126
 127   /* Update number of bits */
 128   if ((context->count[0] += ((UINT4)inputLen << 3))
 129    < ((UINT4)inputLen << 3))
 130  context->count[1]++;
 131   context->count[1] += ((UINT4)inputLen >> 29);
 132
 133   partLen = 64 - index;
 134
 135   /* Transform as many times as possible. */
 136   if (inputLen >= partLen) {
 137  memcpy ((POINTER)&context->buffer[index], (POINTER)input, partLen);
 138  MD5Transform (context->state, context->buffer);
 139
 140  for (i = partLen; i + 63 < inputLen; i += 64)
 141    MD5Transform (context->state, &input[i]);
 142
 143  index = 0;
 144   }
 145   else
 146  i = 0;
 147
 148   /* Buffer remaining input */
 149   memcpy ((POINTER)&context->buffer[index], (POINTER)&input[i], inputLen-i);
 150 }
 151
 152 /*
 153  * MD5 finalization. Ends an MD5 message-digest operation, writing the
 154  * the message digest and zeroizing the context.
 155  */
 156 void MD5Final (digest, context)
 157 unsigned char digest[16];                         /* message digest */
 158 MD5_CTX *context;                                       /* context */
 159 {
 160   unsigned char bits[8];
 161   unsigned int index, padLen;
 162
 163   /* Save number of bits */
 164   Encode (bits, context->count, 8);
 165
 166   /* Pad out to 56 mod 64.
 167 */
 168   index = (unsigned int)((context->count[0] >> 3) & 0x3f);
 169   padLen = (index < 56) ? (56 - index) : (120 - index);
 170   MD5Update (context, PADDING, padLen);
 171
 172   /* Append length (before padding) */
 173   MD5Update (context, bits, 8);
 174   /* Store state in digest */
 175   Encode (digest, context->state, 16);
 176
 177   /* Zeroize sensitive information. */
 178   memset ((POINTER)context, 0, sizeof(*context));
 179 }
 180
 181 /* MD5 basic transformation. Transforms state based on block.
 182  */
 183 static void MD5Transform (state, block)
 184 UINT4 state[4];
 185 unsigned char block[64];
 186 {
 187   UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
 188
 189   Decode (x, block, 64);
 190
 191   /* Round 1 */
 192   FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
 193   FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
 194   FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
 195   FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
 196   FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
 197   FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
 198   FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
 199   FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
 200   FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
 201   FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
 202   FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
 203   FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
 204   FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
 205   FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
 206   FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
 207   FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
 208
 209  /* Round 2 */
 210   GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
 211   GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
 212   GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
 213   GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
 214   GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
 215   GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
 216   GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
 217   GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
 218   GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
 219   GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
 220   GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
 221   GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
 222   GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
 223   GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
 224   GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
 225   GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
 226
 227   /* Round 3 */
 228   HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
 229   HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
 230   HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
 231   HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
 232   HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
 233   HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
 234   HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
 235   HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
 236   HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
 237   HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
 238   HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
 239   HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
 240   HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
 241   HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
 242   HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
 243   HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
 244
 245   /* Round 4 */
 246   II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
 247   II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
 248   II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
 249   II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
 250   II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
 251   II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
 252   II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
 253   II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
 254   II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
 255   II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
 256   II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
 257   II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
 258   II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
 259   II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
 260   II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
 261   II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
 262
 263   state[0] += a;
 264   state[1] += b;
 265   state[2] += c;
 266   state[3] += d;
 267
 268   /* Zeroize sensitive information. */
 269   memset ((POINTER)x, 0, sizeof(x));
 270 }
 271
 272 /* Encodes input (UINT4) into output (unsigned char). Assumes len is
 273   a multiple of 4.
 274  */
 275 static void Encode (output, input, len)
 276 unsigned char *output;
 277 UINT4 *input;
 278 unsigned int len;
 279 {
 280   unsigned int i, j;
 281
 282   for (i = 0, j = 0; j < len; i++, j += 4) {
 283  output[j] = (unsigned char)(input[i] & 0xff);
 284  output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
 285  output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
 286  output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
 287   }
 288 }
 289
 290 /* Decodes input (unsigned char) into output (UINT4). Assumes len is
 291   a multiple of 4.
 292  */
 293 static void Decode (output, input, len)
 294 UINT4 *output;
 295 unsigned char *input;
 296 unsigned int len;
 297 {
 298   unsigned int i, j;
 299
 300   for (i = 0, j = 0; j < len; i++, j += 4)
 301  output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
 302    (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
 303 }