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
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