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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 /* Constants for MD5Transform routine. */
  35 #define S11 7
  36 #define S12 12
  37 #define S13 17
  38 #define S14 22
  39 #define S21 5
  40 #define S22 9
  41 #define S23 14
  42 #define S24 20
  43 #define S31 4
  44 #define S32 11
  45 #define S33 16
  46 #define S34 23
  47 #define S41 6
  48 #define S42 10
  49 #define S43 15
  50 #define S44 21
  51
  52 static void MD5Transform(UINT4 [4], unsigned char [64]);
  53 static void Encode(unsigned char *, UINT4 *, unsigned int);
  54 static void Decode(UINT4 *, unsigned char *, unsigned int);
  55
  56 static unsigned char PADDING[64] = {
  57     0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  58     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  59     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
  61 };
  62
  63 /* F, G, H and I are basic MD5 functions. */
  64 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
  65 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
  66 #define H(x, y, z) ((x) ^ (y) ^ (z))
  67 #define I(x, y, z) ((y) ^ ((x) | (~z)))
  68
  69 /* ROTATE_LEFT rotates x left n bits. */
  70 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
  71
  72 /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
  73 Rotation is separate from addition to prevent recomputation. */
  74 #define FF(a, b, c, d, x, s, ac) \
  75     { \
  76         (a) += F((b), (c), (d)) + (x) + (UINT4)(ac); \
  77         (a) = ROTATE_LEFT((a), (s)); \
  78         (a) += (b); \
  79     }
  80 #define GG(a, b, c, d, x, s, ac) \
  81     { \
  82         (a) += G((b), (c), (d)) + (x) + (UINT4)(ac); \
  83         (a) = ROTATE_LEFT((a), (s)); \
  84         (a) += (b); \
  85     }
  86 #define HH(a, b, c, d, x, s, ac) \
  87     { \
  88         (a) += H((b), (c), (d)) + (x) + (UINT4)(ac); \
  89         (a) = ROTATE_LEFT((a), (s)); \
  90         (a) += (b); \
  91     }
  92 #define II(a, b, c, d, x, s, ac) \
  93     { \
  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 void
 101 MD5Init(MD5_CTX *context)
 102 {
 103     context->count[0] = context->count[1] = 0;
 104     /* Load magic initialization constants. */
 105     context->state[0] = 0x67452301;
 106     context->state[1] = 0xefcdab89;
 107     context->state[2] = 0x98badcfe;
 108     context->state[3] = 0x10325476;
 109 }
 110
 111 /* MD5 block update operation.  Continues an MD5 message-digest
 112  * operation, processing another message block, and updating the
 113  * context. */
 114 void
 115 MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputLen)
 116 {
 117     unsigned int i, index, partLen;
 118
 119     /* Compute number of bytes mod 64 */
 120     index = (unsigned int)((context->count[0] >> 3) & 0x3F);
 121
 122     /* Update number of bits */
 123     if ((context->count[0] += ((UINT4)inputLen << 3)) < ((UINT4)inputLen << 3))
 124         context->count[1]++;
 125     context->count[1] += ((UINT4)inputLen >> 29);
 126
 127     partLen = 64 - index;
 128
 129     /* Transform as many times as possible. */
 130     if (inputLen >= partLen) {
 131         memcpy(&context->buffer[index], input, partLen);
 132         MD5Transform(context->state, context->buffer);
 133
 134         for (i = partLen; i + 63 < inputLen; i += 64)
 135             MD5Transform(context->state, &input[i]);
 136
 137         index = 0;
 138     } else
 139          i = 0;
 140
 141     /* Buffer remaining input */
 142     memcpy(&context->buffer[index], &input[i], inputLen - i);
 143 }
 144
 145 /* MD5 finalization. Ends an MD5 message-digest operation, writing the
 146  * the message digest and zeroizing the context. */
 147 void
 148 MD5Final(unsigned char digest[16], MD5_CTX *context)
 149 {
 150     unsigned char bits[8];
 151     unsigned int index;
 152     unsigned int padLen;
 153
 154     /* Save number of bits */
 155     Encode(bits, context->count, 8);
 156
 157     /* Pad out to 56 mod 64. */
 158     index = (unsigned int)((context->count[0] >> 3) & 0x3f);
 159     padLen = (index < 56) ? (56 - index) : (120 - index);
 160     MD5Update(context, PADDING, padLen);
 161
 162     /* Append length (before padding) */
 163     MD5Update(context, bits, 8);
 164     /* Store state in digest */
 165     Encode(digest, context->state, 16);
 166
 167     /* Zeroize sensitive information. */
 168     memset(context, 0, sizeof(*context));
 169 }
 170
 171 /* MD5 basic transformation.  Transforms state based on block. */
 172 static void
 173 MD5Transform(UINT4 state[4], unsigned char block[64])
 174 {
 175     UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
 176
 177     Decode(x, block, 64);
 178
 179     /* Round 1 */
 180     FF(a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
 181     FF(d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
 182     FF(c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
 183     FF(b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
 184     FF(a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
 185     FF(d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
 186     FF(c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
 187     FF(b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
 188     FF(a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
 189     FF(d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
 190     FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
 191     FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
 192     FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
 193     FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
 194     FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
 195     FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
 196
 197     /* Round 2 */
 198     GG(a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
 199     GG(d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
 200     GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
 201     GG(b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
 202     GG(a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
 203     GG(d, a, b, c, x[10], S22,  0x2441453); /* 22 */
 204     GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
 205     GG(b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
 206     GG(a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
 207     GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
 208     GG(c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
 209     GG(b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
 210     GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
 211     GG(d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
 212     GG(c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
 213     GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
 214
 215     /* Round 3 */
 216     HH(a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
 217     HH(d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
 218     HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
 219     HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
 220     HH(a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
 221     HH(d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
 222     HH(c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
 223     HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
 224     HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
 225     HH(d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
 226     HH(c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
 227     HH(b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
 228     HH(a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
 229     HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
 230     HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
 231     HH(b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
 232
 233     /* Round 4 */
 234     II(a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
 235     II(d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
 236     II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
 237     II(b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
 238     II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
 239     II(d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
 240     II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
 241     II(b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
 242     II(a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
 243     II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
 244     II(c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
 245     II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
 246     II(a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
 247     II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
 248     II(c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
 249     II(b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
 250
 251     state[0] += a;
 252     state[1] += b;
 253     state[2] += c;
 254     state[3] += d;
 255
 256     /* Zeroize sensitive information. */
 257     memset(x, 0, sizeof(x));
 258 }
 259
 260 /* Encodes input (UINT4) into output (unsigned char).  Assumes len is a
 261  * multiple of 4. */
 262 static void
 263 Encode(unsigned char *output, UINT4 *input, unsigned int len)
 264 {
 265     unsigned int i, j;
 266
 267     for (i = 0, j = 0; j < len; i++, j += 4) {
 268         output[j] = (unsigned char)(input[i] & 0xff);
 269         output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
 270         output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
 271         output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
 272     }
 273 }
 274
 275 /* Decodes input (unsigned char) into output (UINT4).  Assumes len is a
 276  * multiple of 4. */
 277 static void
 278 Decode(UINT4 *output, unsigned char *input, unsigned int len)
 279 {
 280     unsigned int i, j;
 281
 282     for (i = 0, j = 0; j < len; i++, j += 4)
 283         output[i] = ((UINT4)input[j]) |
 284             (((UINT4)input[j+1]) << 8) |
 285             (((UINT4)input[j+2]) << 16) |
 286             (((UINT4)input[j+3]) << 24);
 287 }