dlls/rsaenh/md2.c

   1 /*
   2  * dlls/rsaenh/md2.c
   3  * MD2 (RFC 1319) hash function implementation by Tom St Denis
   4  *
   5  * Copyright 2004 Michael Jung
   6  * Based on public domain code by Tom St Denis (tomstdenis@iahu.ca)
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  21  */
  22
  23 /*
  24  * This file contains code from the LibTomCrypt cryptographic
  25  * library written by Tom St Denis (tomstdenis@iahu.ca). LibTomCrypt
  26  * is in the public domain. The code in this file is tailored to
  27  * special requirements. Take a look at http://libtomcrypt.org for the
  28  * original version.
  29  */
  30
  31 #include "tomcrypt.h"
  32
  33 static const unsigned char PI_SUBST[256] = {
  34   41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
  35   19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
  36   76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
  37   138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
  38   245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
  39   148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
  40   39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
  41   181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
  42   150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
  43   112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
  44   96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
  45   85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
  46   234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
  47   129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
  48   8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
  49   203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
  50   166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
  51   31, 26, 219, 153, 141, 51, 159, 17, 131, 20
  52 };
  53
  54 /* adds 16 bytes to the checksum */
  55 static void md2_update_chksum(md2_state *md2)
  56 {
  57    int j;
  58    unsigned char L;
  59    L = md2->chksum[15];
  60    for (j = 0; j < 16; j++) {
  61
  62 /* caution, the RFC says its "C[j] = S[M[i*16+j] xor L]" but the reference source code [and test vectors] say
  63    otherwise.
  64 */
  65        L = (md2->chksum[j] ^= PI_SUBST[(int)(md2->buf[j] ^ L)] & 255);
  66    }
  67 }
  68
  69 static void md2_compress(md2_state *md2)
  70 {
  71    int j, k;
  72    unsigned char t;
  73
  74    /* copy block */
  75    for (j = 0; j < 16; j++) {
  76        md2->X[16+j] = md2->buf[j];
  77        md2->X[32+j] = md2->X[j] ^ md2->X[16+j];
  78    }
  79
  80    t = (unsigned char)0;
  81
  82    /* do 18 rounds */
  83    for (j = 0; j < 18; j++) {
  84        for (k = 0; k < 48; k++) {
  85            t = (md2->X[k] ^= PI_SUBST[(int)(t & 255)]);
  86        }
  87        t = (t + (unsigned char)j) & 255;
  88    }
  89 }
  90
  91 int md2_init(md2_state *md2)
  92 {
  93    /* MD2 uses a zero'ed state... */
  94    memset(md2->X, 0, sizeof(md2->X));
  95    memset(md2->chksum, 0, sizeof(md2->chksum));
  96    memset(md2->buf, 0, sizeof(md2->buf));
  97    md2->curlen = 0;
  98    return CRYPT_OK;
  99 }
 100
 101 int md2_process(md2_state *md2, const unsigned char *buf, unsigned long len)
 102 {
 103     unsigned long n;
 104
 105     if (md2->curlen > sizeof(md2->buf)) {
 106        return CRYPT_INVALID_ARG;
 107     }
 108     while (len > 0) {
 109         n = MIN(len, (16 - md2->curlen));
 110         memcpy(md2->buf + md2->curlen, buf, (size_t)n);
 111         md2->curlen += n;
 112         buf         += n;
 113         len         -= n;
 114
 115         /* is 16 bytes full? */
 116         if (md2->curlen == 16) {
 117             md2_compress(md2);
 118             md2_update_chksum(md2);
 119             md2->curlen = 0;
 120         }
 121     }
 122     return CRYPT_OK;
 123 }
 124
 125 int md2_done(md2_state * md2, unsigned char *hash)
 126 {
 127     unsigned long i, k;
 128
 129     if (md2->curlen >= sizeof(md2->buf)) {
 130        return CRYPT_INVALID_ARG;
 131     }
 132
 133     /* pad the message */
 134     k = 16 - md2->curlen;
 135     for (i = md2->curlen; i < 16; i++) {
 136         md2->buf[i] = (unsigned char)k;
 137     }
 138
 139     /* hash and update */
 140     md2_compress(md2);
 141     md2_update_chksum(md2);
 142
 143     /* hash checksum */
 144     memcpy(md2->buf, md2->chksum, 16);
 145     md2_compress(md2);
 146
 147     /* output is lower 16 bytes of X */
 148     memcpy(hash, md2->X, 16);
 149
 150     return CRYPT_OK;
 151 }