sys/kern/md5c.c

   1 /*
   2  * MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
   3  *
   4  * Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
   5  * rights reserved.
   6  *
   7  * License to copy and use this software is granted provided that it
   8  * is identified as the "RSA Data Security, Inc. MD5 Message-Digest
   9  * Algorithm" in all material mentioning or referencing this software
  10  * or this function.
  11  *
  12  * License is also granted to make and use derivative works provided
  13  * that such works are identified as "derived from the RSA Data
  14  * Security, Inc. MD5 Message-Digest Algorithm" in all material
  15  * mentioning or referencing the derived work.
  16  *
  17  * RSA Data Security, Inc. makes no representations concerning either
  18  * the merchantability of this software or the suitability of this
  19  * software for any particular purpose. It is provided "as is"
  20  * without express or implied warranty of any kind.
  21  *
  22  * These notices must be retained in any copies of any part of this
  23  * documentation and/or software.
  24  *
  25  * $FreeBSD: src/sys/kern/md5c.c,v 1.27 2006/03/30 18:45:50 pjd Exp $
  26  *
  27  * This code is the same as the code published by RSA Inc.  It has been
  28  * edited for clarity and style only.
  29  */
  30
  31 /*
  32  * This file should be kept in sync with src/lib/libmd/md5c.c
  33  */
  34 #include <sys/types.h>
  35
  36 #ifdef _KERNEL
  37 #include <sys/systm.h>
  38 #else
  39 #include <string.h>
  40 #endif
  41
  42 #include <machine/endian.h>
  43 #include <sys/endian.h>
  44 #include <sys/md5.h>
  45
  46 static void __kern__MD5Transform(u_int32_t [4], const unsigned char [64]);
  47
  48 #if (BYTE_ORDER == LITTLE_ENDIAN)
  49 #define Encode memcpy
  50 #define Decode memcpy
  51 #else
  52
  53 /*
  54  * Encodes input (u_int32_t) into output (unsigned char). Assumes len is
  55  * a multiple of 4.
  56  */
  57
  58 static void
  59 Encode (unsigned char *output, u_int32_t *input, unsigned int len)
  60 {
  61         unsigned int i;
  62         uint32_t ip;
  63
  64         for (i = 0; i < len / 4; i++) {
  65                 ip = input[i];
  66                 *output++ = ip;
  67                 *output++ = ip >> 8;
  68                 *output++ = ip >> 16;
  69                 *output++ = ip >> 24;
  70         }
  71 }
  72
  73 /*
  74  * Decodes input (unsigned char) into output (u_int32_t). Assumes len is
  75  * a multiple of 4.
  76  */
  77
  78 static void
  79 Decode (u_int32_t *output, const unsigned char *input, unsigned int len)
  80 {
  81         unsigned int i;
  82
  83         for (i = 0; i < len; i += 4) {
  84                 *output++ = input[i] | (input[i+1] << 8) | (input[i+2] << 16) |
  85                     (input[i+3] << 24);
  86         }
  87 }
  88 #endif
  89
  90 static unsigned char PADDING[64] = {
  91   0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  92   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  93   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  94 };
  95
  96 /* F, G, H and I are basic MD5 functions. */
  97 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
  98 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
  99 #define H(x, y, z) ((x) ^ (y) ^ (z))
 100 #define I(x, y, z) ((y) ^ ((x) | (~z)))
 101
 102 /* ROTATE_LEFT rotates x left n bits. */
 103 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
 104
 105 /*
 106  * FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
 107  * Rotation is separate from addition to prevent recomputation.
 108  */
 109 #define FF(a, b, c, d, x, s, ac) { \
 110         (a) += F ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
 111         (a) = ROTATE_LEFT ((a), (s)); \
 112         (a) += (b); \
 113         }
 114 #define GG(a, b, c, d, x, s, ac) { \
 115         (a) += G ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
 116         (a) = ROTATE_LEFT ((a), (s)); \
 117         (a) += (b); \
 118         }
 119 #define HH(a, b, c, d, x, s, ac) { \
 120         (a) += H ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
 121         (a) = ROTATE_LEFT ((a), (s)); \
 122         (a) += (b); \
 123         }
 124 #define II(a, b, c, d, x, s, ac) { \
 125         (a) += I ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
 126         (a) = ROTATE_LEFT ((a), (s)); \
 127         (a) += (b); \
 128         }
 129
 130 /* MD5 initialization. Begins an MD5 operation, writing a new context. */
 131
 132 int
 133 MD5Init (MD5_CTX *context)
 134 {
 135
 136         context->Nl = context->Nh = 0;
 137
 138         /* Load magic initialization constants.  */
 139         context->A = 0x67452301;
 140         context->B = 0xefcdab89;
 141         context->C = 0x98badcfe;
 142         context->D = 0x10325476;
 143
 144         return 1;
 145 }
 146
 147 /*
 148  * MD5 block update operation. Continues an MD5 message-digest
 149  * operation, processing another message block, and updating the
 150  * context.
 151  */
 152
 153 void
 154 MD5Update (MD5_CTX *context, const void *in, unsigned int inputLen)
 155 {
 156         unsigned int i, index, partLen;
 157         const unsigned char *input = in;
 158
 159         /* Compute number of bytes mod 64 */
 160         index = (unsigned int)((context->Nl >> 3) & 0x3F);
 161
 162         /* Update number of bits */
 163         if ((context->Nl += ((u_int32_t)inputLen << 3))
 164             < ((u_int32_t)inputLen << 3))
 165                 context->Nh++;
 166         context->Nh += ((u_int32_t)inputLen >> 29);
 167
 168         partLen = 64 - index;
 169
 170         /* Transform as many times as possible. */
 171         if (inputLen >= partLen) {
 172                 memcpy((void *)&((char *)context->data)[index], (const void *)input,
 173                     partLen);
 174                 __kern__MD5Transform (&context->A, (char *)context->data);
 175
 176                 for (i = partLen; i + 63 < inputLen; i += 64)
 177                         __kern__MD5Transform (&context->A, &input[i]);
 178
 179                 index = 0;
 180         }
 181         else
 182                 i = 0;
 183
 184         /* Buffer remaining input */
 185         memcpy ((void *)&((char *)context->data)[index], (const void *)&input[i],
 186             inputLen-i);
 187 }
 188
 189 /*
 190  * MD5 padding. Adds padding followed by original length.
 191  */
 192
 193 static void
 194 __kern__MD5Pad (MD5_CTX *context)
 195 {
 196         unsigned char bits[8];
 197         unsigned int index, padLen;
 198
 199         /* Save number of bits */
 200         Encode (bits, &context->Nl, 8);
 201
 202         /* Pad out to 56 mod 64. */
 203         index = (unsigned int)((context->Nl >> 3) & 0x3f);
 204         padLen = (index < 56) ? (56 - index) : (120 - index);
 205         MD5Update (context, PADDING, padLen);
 206
 207         /* Append length (before padding) */
 208         MD5Update (context, bits, 8);
 209 }
 210
 211 /*
 212  * MD5 finalization. Ends an MD5 message-digest operation, writing the
 213  * the message digest and zeroizing the context.
 214  */
 215
 216 void
 217 MD5Final (unsigned char digest[16], MD5_CTX *context)
 218 {
 219         /* Do padding. */
 220         __kern__MD5Pad (context);
 221
 222         /* Store state in digest */
 223         Encode (digest, &context->A, 16);
 224
 225         /* Zeroize sensitive information. */
 226         memset ((void *)context, 0, sizeof (*context));
 227 }
 228
 229 /* MD5 basic transformation. Transforms state based on block. */
 230
 231 static void
 232 __kern__MD5Transform (u_int32_t state[4], const unsigned char block[64])
 233 {
 234         u_int32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16];
 235
 236         Decode (x, block, 64);
 237
 238         /* Round 1 */
 239 #define S11 7
 240 #define S12 12
 241 #define S13 17
 242 #define S14 22
 243         FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
 244         FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
 245         FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
 246         FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
 247         FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
 248         FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
 249         FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
 250         FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
 251         FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
 252         FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
 253         FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
 254         FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
 255         FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
 256         FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
 257         FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
 258         FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
 259
 260         /* Round 2 */
 261 #define S21 5
 262 #define S22 9
 263 #define S23 14
 264 #define S24 20
 265         GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
 266         GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
 267         GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
 268         GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
 269         GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
 270         GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
 271         GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
 272         GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
 273         GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
 274         GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
 275         GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
 276         GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
 277         GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
 278         GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
 279         GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
 280         GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
 281
 282         /* Round 3 */
 283 #define S31 4
 284 #define S32 11
 285 #define S33 16
 286 #define S34 23
 287         HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
 288         HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
 289         HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
 290         HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
 291         HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
 292         HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
 293         HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
 294         HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
 295         HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
 296         HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
 297         HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
 298         HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
 299         HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
 300         HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
 301         HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
 302         HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
 303
 304         /* Round 4 */
 305 #define S41 6
 306 #define S42 10
 307 #define S43 15
 308 #define S44 21
 309         II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
 310         II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
 311         II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
 312         II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
 313         II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
 314         II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
 315         II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
 316         II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
 317         II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
 318         II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
 319         II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
 320         II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
 321         II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
 322         II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
 323         II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
 324         II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
 325
 326         state[0] += a;
 327         state[1] += b;
 328         state[2] += c;
 329         state[3] += d;
 330
 331         /* Zeroize sensitive information. */
 332         memset ((void *)x, 0, sizeof (x));
 333 }