Newer
Older
* The MD2 hash function, described in RFC 1319.
*/
/* nettle, low-level cryptographics library
*
* Copyright (C) 2003 Niels Mller, Andreas Sigfridsson
*
* The nettle library 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.
*
* The nettle library 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 the nettle library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
/* This code originates from the Python Cryptography Toolkit, version 1.0.1.
Further hacked by Andreas Sigfridsson and Niels Mller. Original license:
===================================================================
Distribute and use freely; there are no restrictions on further
dissemination and usage except those imposed by the laws of your
country of residence. This software is provided "as is" without
warranty of fitness for use or suitability for any purpose, express
or implied. Use at your own risk or not at all.
===================================================================
Incorporating the code into commercial products is permitted; you do
not have to make source available or contribute your changes back
(though that would be nice).
--amk (www.amk.ca) */
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
#if HAVE_CONFIG_H
# include "config.h"
#endif
#include <assert.h>
#include <string.h>
#include "md2.h"
#include "macros.h"
static const uint8_t
S[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
};
static void
md2_transform(struct md2_ctx *ctx, const uint8_t *data)
{
unsigned i;
uint8_t t;
memcpy(ctx->X + 16, data, MD2_DATA_SIZE);
for (i = 0, t = ctx->C[15];
i<MD2_DATA_SIZE; i++)
{
ctx->X[2 * MD2_DATA_SIZE + i]
= ctx->X[i] ^ ctx->X[MD2_DATA_SIZE + i];
t = (ctx->C[i] ^= S[data[i]^t]);
}
for (i = t = 0;
i< MD2_DATA_SIZE + 2;
t = (t + i) & 0xff, i++)
{
unsigned j;
for (j = 0; j < 3 * MD2_DATA_SIZE; j++)
t = (ctx->X[j] ^= S[t]);
}
}
#if 0
static void
md2_final(struct md2_ctx *ctx)
{
unsigned left = MD2_DATA_SIZE - ctx->index;
memset(ctx->block + ctx->index, left, left);
md2_transform(ctx, ctx->block);
}
#endif
void
md2_init(struct md2_ctx *ctx)
{
memset(ctx, 0, sizeof(*ctx));
}
void
md2_update(struct md2_ctx *ctx,
unsigned length,
const uint8_t *data)
{
if (ctx->index)
{
/* Try to fill partial block */
unsigned left = MD2_DATA_SIZE - ctx->index;
if (length < left)
{
memcpy(ctx->block + ctx->index, data, length);
ctx->index += length;
return; /* Finished */
}
else
{
memcpy(ctx->block + ctx->index, data, left);
md2_transform(ctx, ctx->block);
data += left;
length -= left;
}
}
while (length >= MD2_DATA_SIZE)
{
md2_transform(ctx, data);
data += MD2_DATA_SIZE;
length -= MD2_DATA_SIZE;
}
if ((ctx->index = length)) /* This assignment is intended */
/* Buffer leftovers */
memcpy(ctx->block, data, length);
}
void
md2_digest(struct md2_ctx *ctx,
unsigned length,
uint8_t *digest)
{
unsigned left;
assert(length <= MD2_DIGEST_SIZE);
left = MD2_DATA_SIZE - ctx->index;
memset(ctx->block + ctx->index, left, left);
md2_transform(ctx, ctx->block);
md2_transform(ctx, ctx->C);
memcpy(digest, ctx->X, length);
md2_init(ctx);
}