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 = 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 } 152