lib/hcrypto/md2.c

   1 /*
   2  * Copyright (c) 2006 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifdef HAVE_CONFIG_H
  35 #include "config.h"
  36
  37 RCSID("$Id$");
  38 #endif
  39
  40 #include "hash.h"
  41 #include "md2.h"
  42
  43 static const unsigned char subst[256] = {
  44   41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
  45   19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
  46   76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
  47   138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
  48   245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
  49   148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
  50   39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
  51   181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
  52   150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
  53   112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
  54   96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
  55   85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
  56   234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
  57   129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
  58   8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
  59   203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
  60   166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
  61   31, 26, 219, 153, 141, 51, 159, 17, 131, 20
  62 };
  63
  64 void
  65 MD2_Init (struct md2 *m)
  66 {
  67     memset(m, 0, sizeof(*m));
  68 }
  69
  70 static void
  71 calc(struct md2 *m, const void *v)
  72 {
  73     unsigned char x[48], L;
  74     const unsigned char *p = v;
  75     int i, j, t;
  76
  77     L = m->checksum[15];
  78     for (i = 0; i < 16; i++)
  79         L = m->checksum[i] ^= subst[p[i] ^ L];
  80
  81     for (i = 0; i < 16; i++) {
  82         x[i]      = m->state[i];
  83         x[i + 16] = p[i];
  84         x[i + 32] = x[i] ^ p[i];
  85     }
  86
  87     t = 0;
  88     for (i = 0; i < 18; i++) {
  89         for (j = 0; j < 48; j++)
  90             t = x[j] ^= subst[t];
  91         t = (t + i) & 0xff;
  92     }
  93
  94     memcpy(m->state, x, 16);
  95     memset(x, 0, sizeof(x));
  96 }
  97
  98 void
  99 MD2_Update (struct md2 *m, const void *v, size_t len)
 100 {
 101     size_t idx = m->len & 0xf;
 102     const unsigned char *p = v;
 103
 104     m->len += len;
 105     if (len + idx >= 16) {
 106         if (idx) {
 107             memcpy(m->data + idx, p, 16 - idx);
 108             calc(m, m->data);
 109             p += 16;
 110             len -= 16 - idx;
 111         }
 112         while (len >= 16) {
 113             calc(m, p);
 114             p += 16;
 115             len -= 16;
 116         }
 117         idx = 0;
 118     }
 119
 120     memcpy(m->data + idx, p, len);
 121 }
 122
 123 void
 124 MD2_Final (void *res, struct md2 *m)
 125 {
 126     unsigned char pad[16];
 127     size_t padlen;
 128
 129     padlen = 16 - (m->len % 16);
 130     memset(pad, padlen, padlen);
 131
 132     MD2_Update(m, pad, padlen);
 133     memcpy(pad, m->checksum, 16);
 134     MD2_Update(m, pad, 16);
 135
 136     memcpy(res, m->state, MD2_DIGEST_LENGTH);
 137     memset(m, 0, sizeof(m));
 138 }