src/libstrongswan/plugins/md5/md5_hasher.c

   1 /*
   2  * Copyright (C) 2005-2006 Martin Willi
   3  * Copyright (C) 2005 Jan Hutter
   4  * Hochschule fuer Technik Rapperswil
   5  * Copyright (C) 1991-1992, RSA Data Security, Inc. Created 1991.
   6  * All rights reserved.
   7  *
   8  * Derived from the RSA Data Security, Inc. MD5 Message-Digest Algorithm.
   9  * Ported to fulfill hasher_t interface.
  10  *
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU General Public License as published by the
  13  * Free Software Foundation; either version 2 of the License, or (at your
  14  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  15  *
  16  * This program is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  18  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  19  * for more details.
  20  */
  21
  22 #include <string.h>
  23
  24 #include "md5_hasher.h"
  25
  26
  27 /* Constants for MD5Transform routine. */
  28 #define S11 7
  29 #define S12 12
  30 #define S13 17
  31 #define S14 22
  32 #define S21 5
  33 #define S22 9
  34 #define S23 14
  35 #define S24 20
  36 #define S31 4
  37 #define S32 11
  38 #define S33 16
  39 #define S34 23
  40 #define S41 6
  41 #define S42 10
  42 #define S43 15
  43 #define S44 21
  44
  45 static u_int8_t PADDING[64] = {
  46   0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  47   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  48   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  49 };
  50
  51 /*
  52  * ugly macro stuff
  53  */
  54 /* F, G, H and I are basic MD5 functions.
  55  */
  56 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
  57 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
  58 #define H(x, y, z) ((x) ^ (y) ^ (z))
  59 #define I(x, y, z) ((y) ^ ((x) | (~z)))
  60
  61 /* ROTATE_LEFT rotates x left n bits.
  62  */
  63 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
  64
  65 /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
  66 Rotation is separate from addition to prevent recomputation.
  67  */
  68 #define FF(a, b, c, d, x, s, ac) { \
  69  (a) += F ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
  70  (a) = ROTATE_LEFT ((a), (s)); \
  71  (a) += (b); \
  72   }
  73 #define GG(a, b, c, d, x, s, ac) { \
  74  (a) += G ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
  75  (a) = ROTATE_LEFT ((a), (s)); \
  76  (a) += (b); \
  77   }
  78 #define HH(a, b, c, d, x, s, ac) { \
  79  (a) += H ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
  80  (a) = ROTATE_LEFT ((a), (s)); \
  81  (a) += (b); \
  82   }
  83 #define II(a, b, c, d, x, s, ac) { \
  84  (a) += I ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
  85  (a) = ROTATE_LEFT ((a), (s)); \
  86  (a) += (b); \
  87   }
  88
  89
  90
  91 typedef struct private_md5_hasher_t private_md5_hasher_t;
  92
  93 /**
  94  * Private data structure with hasing context.
  95  */
  96 struct private_md5_hasher_t {
  97         /**
  98          * Public interface for this hasher.
  99          */
 100         md5_hasher_t public;
 101
 102         /*
 103          * State of the hasher.
 104          */
 105         u_int32_t state[5];
 106         u_int32_t count[2];
 107         u_int8_t buffer[64];
 108 };
 109
 110
 111 #if BYTE_ORDER != LITTLE_ENDIAN
 112
 113 /* Encodes input (u_int32_t) into output (u_int8_t). Assumes len is
 114  * a multiple of 4.
 115  */
 116 static void Encode (u_int8_t *output, u_int32_t *input, size_t len)
 117 {
 118         size_t i, j;
 119
 120         for (i = 0, j = 0; j < len; i++, j += 4)
 121         {
 122                 output[j] = (u_int8_t)(input[i] & 0xff);
 123                 output[j+1] = (u_int8_t)((input[i] >> 8) & 0xff);
 124                 output[j+2] = (u_int8_t)((input[i] >> 16) & 0xff);
 125                 output[j+3] = (u_int8_t)((input[i] >> 24) & 0xff);
 126         }
 127 }
 128
 129 /* Decodes input (u_int8_t) into output (u_int32_t). Assumes len is
 130  * a multiple of 4.
 131  */
 132 static void Decode(u_int32_t *output, u_int8_t *input, size_t len)
 133 {
 134         size_t i, j;
 135
 136         for (i = 0, j = 0; j < len; i++, j += 4)
 137         {
 138                 output[i] = ((u_int32_t)input[j]) | (((u_int32_t)input[j+1]) << 8) |
 139                 (((u_int32_t)input[j+2]) << 16) | (((u_int32_t)input[j+3]) << 24);
 140         }
 141 }
 142
 143 #elif BYTE_ORDER == LITTLE_ENDIAN
 144  #define Encode memcpy
 145  #define Decode memcpy
 146 #endif
 147
 148 /* MD5 basic transformation. Transforms state based on block.
 149  */
 150 static void MD5Transform(u_int32_t state[4], u_int8_t block[64])
 151 {
 152         u_int32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16];
 153
 154         Decode(x, block, 64);
 155
 156         /* Round 1 */
 157         FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
 158         FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
 159         FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
 160         FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
 161         FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
 162         FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
 163         FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
 164         FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
 165         FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
 166         FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
 167         FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
 168         FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
 169         FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
 170         FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
 171         FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
 172         FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
 173
 174         /* Round 2 */
 175         GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
 176         GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
 177         GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
 178         GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
 179         GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
 180         GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
 181         GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
 182         GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
 183         GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
 184         GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
 185         GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
 186         GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
 187         GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
 188         GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
 189         GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
 190         GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
 191
 192         /* Round 3 */
 193         HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
 194         HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
 195         HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
 196         HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
 197         HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
 198         HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
 199         HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
 200         HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
 201         HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
 202         HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
 203         HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
 204         HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
 205         HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
 206         HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
 207         HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
 208         HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
 209
 210         /* Round 4 */
 211         II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
 212         II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
 213         II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
 214         II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
 215         II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
 216         II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
 217         II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
 218         II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
 219         II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
 220         II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
 221         II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
 222         II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
 223         II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
 224         II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
 225         II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
 226         II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
 227
 228         state[0] += a;
 229         state[1] += b;
 230         state[2] += c;
 231         state[3] += d;
 232 }
 233
 234 /* MD5 block update operation. Continues an MD5 message-digest
 235  * operation, processing another message block, and updating the
 236  * context.
 237  */
 238 static void MD5Update(private_md5_hasher_t *this, u_int8_t *input, size_t inputLen)
 239 {
 240         u_int32_t i;
 241         size_t index, partLen;
 242
 243         /* Compute number of bytes mod 64 */
 244         index = (u_int8_t)((this->count[0] >> 3) & 0x3F);
 245
 246         /* Update number of bits */
 247         if ((this->count[0] += (inputLen << 3)) < (inputLen << 3))
 248         {
 249                 this->count[1]++;
 250         }
 251         this->count[1] += (inputLen >> 29);
 252
 253         partLen = 64 - index;
 254
 255         /* Transform as many times as possible. */
 256         if (inputLen >= partLen)
 257         {
 258                 memcpy(&this->buffer[index], input, partLen);
 259                 MD5Transform (this->state, this->buffer);
 260
 261                 for (i = partLen; i + 63 < inputLen; i += 64)
 262                 {
 263                         MD5Transform (this->state, &input[i]);
 264                 }
 265                 index = 0;
 266         }
 267         else
 268         {
 269                 i = 0;
 270         }
 271
 272         /* Buffer remaining input */
 273         memcpy(&this->buffer[index], &input[i], inputLen-i);
 274 }
 275
 276 /* MD5 finalization. Ends an MD5 message-digest operation, writing the
 277  * the message digest and zeroizing the context.
 278  */
 279 static void MD5Final (private_md5_hasher_t *this, u_int8_t digest[16])
 280 {
 281         u_int8_t bits[8];
 282         size_t index, padLen;
 283
 284         /* Save number of bits */
 285         Encode (bits, this->count, 8);
 286
 287         /* Pad out to 56 mod 64. */
 288         index = (size_t)((this->count[0] >> 3) & 0x3f);
 289         padLen = (index < 56) ? (56 - index) : (120 - index);
 290         MD5Update (this, PADDING, padLen);
 291
 292         /* Append length (before padding) */
 293         MD5Update (this, bits, 8);
 294
 295         if (digest != NULL)                     /* Bill Simpson's padding */
 296         {
 297                 /* store state in digest */
 298                 Encode (digest, this->state, 16);
 299         }
 300 }
 301
 302 METHOD(hasher_t, get_hash, void,
 303         private_md5_hasher_t *this, chunk_t chunk, u_int8_t *buffer)
 304 {
 305         MD5Update(this, chunk.ptr, chunk.len);
 306         if (buffer != NULL)
 307         {
 308                 MD5Final(this, buffer);
 309                 this->public.hasher_interface.reset(&(this->public.hasher_interface));
 310         }
 311 }
 312
 313 METHOD(hasher_t, allocate_hash, void,
 314         private_md5_hasher_t *this, chunk_t chunk, chunk_t *hash)
 315 {
 316         chunk_t allocated_hash;
 317
 318         MD5Update(this, chunk.ptr, chunk.len);
 319         if (hash != NULL)
 320         {
 321                 allocated_hash.ptr = malloc(HASH_SIZE_MD5);
 322                 allocated_hash.len = HASH_SIZE_MD5;
 323
 324                 MD5Final(this, allocated_hash.ptr);
 325                 this->public.hasher_interface.reset(&(this->public.hasher_interface));
 326
 327                 *hash = allocated_hash;
 328         }
 329 }
 330
 331 METHOD(hasher_t, get_hash_size, size_t,
 332         private_md5_hasher_t *this)
 333 {
 334         return HASH_SIZE_MD5;
 335 }
 336
 337 METHOD(hasher_t, reset, void,
 338         private_md5_hasher_t *this)
 339 {
 340         this->state[0] = 0x67452301;
 341         this->state[1] = 0xefcdab89;
 342         this->state[2] = 0x98badcfe;
 343         this->state[3] = 0x10325476;
 344         this->count[0] = 0;
 345         this->count[1] = 0;
 346 }
 347
 348 METHOD(hasher_t, destroy, void,
 349         private_md5_hasher_t *this)
 350 {
 351         free(this);
 352 }
 353
 354 /*
 355  * Described in header.
 356  */
 357 md5_hasher_t *md5_hasher_create(hash_algorithm_t algo)
 358 {
 359         private_md5_hasher_t *this;
 360
 361         if (algo != HASH_MD5)
 362         {
 363                 return NULL;
 364         }
 365
 366         INIT(this,
 367                 .public = {
 368                         .hasher_interface = {
 369                                 .get_hash = _get_hash,
 370                                 .allocate_hash = _allocate_hash,
 371                                 .get_hash_size = _get_hash_size,
 372                                 .reset = _reset,
 373                                 .destroy = _destroy,
 374                         },
 375                 },
 376         );
 377
 378         /* initialize */
 379         reset(this);
 380
 381         return &(this->public);
 382 }