1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
/* Functions to compute MD2 message digest of files or memory blocks.
according to the definition of MD2 in RFC 1319 from April 1992.
Copyright (C) 1995-1997, 1999-2003, 2005-2006, 2008-2023 Free Software
Foundation, Inc.
This file is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
This file is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
/* Adapted by Simon Josefsson from public domain Libtomcrypt 1.06 by
Tom St Denis. */
#include <config.h>
/* Specification. */
#include "md2.h"
#include <string.h>
#include <sys/types.h>
#include <minmax.h>
static void md2_update_chksum (struct md2_ctx *md);
static void md2_compress (struct md2_ctx *md);
/* Initialize structure containing state of computation.
(RFC 1319, 3.3: Step 3) */
void
md2_init_ctx (struct md2_ctx *ctx)
{
memset (ctx->X, 0, sizeof (ctx->X));
memset (ctx->chksum, 0, sizeof (ctx->chksum));
memset (ctx->buf, 0, sizeof (ctx->buf));
ctx->curlen = 0;
}
/* Put result from CTX in first 16 bytes following RESBUF. The result
must be in little endian byte order. */
void *
md2_read_ctx (const struct md2_ctx *ctx, void *resbuf)
{
memcpy (resbuf, ctx->X, 16);
return resbuf;
}
/* Process the remaining bytes in the internal buffer and the usual
prolog according to the standard and write the result to RESBUF. */
void *
md2_finish_ctx (struct md2_ctx *ctx, void *resbuf)
{
unsigned long i, k;
/* pad the message */
k = 16 - ctx->curlen;
for (i = ctx->curlen; i < 16; i++)
{
ctx->buf[i] = (unsigned char) k;
}
/* hash and update */
md2_compress (ctx);
md2_update_chksum (ctx);
/* hash checksum */
memcpy (ctx->buf, ctx->chksum, 16);
md2_compress (ctx);
return md2_read_ctx (ctx, resbuf);
}
/* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
result is always in little endian byte order, so that a byte-wise
output yields to the wanted ASCII representation of the message
digest. */
void *
md2_buffer (const char *buffer, size_t len, void *resblock)
{
struct md2_ctx ctx;
/* Initialize the computation context. */
md2_init_ctx (&ctx);
/* Process whole buffer but last len % 64 bytes. */
md2_process_block (buffer, len, &ctx);
/* Put result in desired memory area. */
return md2_finish_ctx (&ctx, resblock);
}
void
md2_process_bytes (const void *buffer, size_t len, struct md2_ctx *ctx)
{
const char *in = buffer;
unsigned long n;
while (len > 0)
{
n = MIN (len, (16 - ctx->curlen));
memcpy (ctx->buf + ctx->curlen, in, (size_t) n);
ctx->curlen += n;
in += n;
len -= n;
/* is 16 bytes full? */
if (ctx->curlen == 16)
{
md2_compress (ctx);
md2_update_chksum (ctx);
ctx->curlen = 0;
}
}
}
static const unsigned char PI_SUBST[256] = {
41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
31, 26, 219, 153, 141, 51, 159, 17, 131, 20
};
/* adds 16 bytes to the checksum */
static void
md2_update_chksum (struct md2_ctx *ctx)
{
int j;
unsigned char L;
L = ctx->chksum[15];
for (j = 0; j < 16; j++)
{
/* caution, the RFC says its "C[j] = S[M[i*16+j] xor L]" but the
reference source code [and test vectors] say otherwise. */
L = (ctx->chksum[j] ^= PI_SUBST[(int) (ctx->buf[j] ^ L)] & 255);
}
}
static void
md2_compress (struct md2_ctx *ctx)
{
size_t j, k;
unsigned char t;
/* copy block */
for (j = 0; j < 16; j++)
{
ctx->X[16 + j] = ctx->buf[j];
ctx->X[32 + j] = ctx->X[j] ^ ctx->X[16 + j];
}
t = (unsigned char) 0;
/* do 18 rounds */
for (j = 0; j < 18; j++)
{
for (k = 0; k < 48; k++)
{
t = (ctx->X[k] ^= PI_SUBST[(int) (t & 255)]);
}
t = (t + (unsigned char) j) & 255;
}
}
/* Process LEN bytes of BUFFER, accumulating context into CTX. */
void
md2_process_block (const void *buffer, size_t len, struct md2_ctx *ctx)
{
md2_process_bytes (buffer, len, ctx);
}
|
