1 /* md2.c
2
3 The MD2 hash function, described in RFC 1319.
4
5 Copyright (C) 2003 Niels Möller, Andreas Sigfridsson
6
7 This file is part of GNU Nettle.
8
9 GNU Nettle is free software: you can redistribute it and/or
10 modify it under the terms of either:
11
12 * the GNU Lesser General Public License as published by the Free
13 Software Foundation; either version 3 of the License, or (at your
14 option) any later version.
15
16 or
17
18 * the GNU General Public License as published by the Free
19 Software Foundation; either version 2 of the License, or (at your
20 option) any later version.
21
22 or both in parallel, as here.
23
24 GNU Nettle is distributed in the hope that it will be useful,
25 but WITHOUT ANY WARRANTY; without even the implied warranty of
26 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
27 General Public License for more details.
28
29 You should have received copies of the GNU General Public License and
30 the GNU Lesser General Public License along with this program. If
31 not, see http://www.gnu.org/licenses/.
32 */
33
34 /* This code originates from the Python Cryptography Toolkit, version 1.0.1.
35 Further hacked by Andreas Sigfridsson and Niels Möller. Original license:
36
37 ===================================================================
38 Distribute and use freely; there are no restrictions on further
39 dissemination and usage except those imposed by the laws of your
40 country of residence. This software is provided "as is" without
41 warranty of fitness for use or suitability for any purpose, express
42 or implied. Use at your own risk or not at all.
43 ===================================================================
44
45 Incorporating the code into commercial products is permitted; you do
46 not have to make source available or contribute your changes back
47 (though that would be nice).
48
49 --amk (www.amk.ca) */
50
51 #if HAVE_CONFIG_H
52 # include "config.h"
53 #endif
54
55 #include <assert.h>
56 #include <string.h>
57
58 #include "md2.h"
59
60 #include "macros.h"
61
62 static const uint8_t
63 S[256] = {
64 41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
65 19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188,
66 76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24,
67 138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251,
68 245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63,
69 148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50,
70 39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165,
71 181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210,
72 150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157,
73 112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27,
74 96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
75 85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197,
76 234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65,
77 129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123,
78 8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233,
79 203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228,
80 166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237,
81 31, 26, 219, 153, 141, 51, 159, 17, 131, 20
82 };
83
84 static void
md2_transform(struct md2_ctx * ctx,const uint8_t * data)85 md2_transform(struct md2_ctx *ctx, const uint8_t *data)
86 {
87 unsigned i;
88 uint8_t t;
89
90 memcpy(ctx->X + 16, data, MD2_BLOCK_SIZE);
91
92 for (i = 0, t = ctx->C[15];
93 i<MD2_BLOCK_SIZE; i++)
94 {
95 ctx->X[2 * MD2_BLOCK_SIZE + i]
96 = ctx->X[i] ^ ctx->X[MD2_BLOCK_SIZE + i];
97 t = (ctx->C[i] ^= S[data[i]^t]);
98 }
99 for (i = t = 0;
100 i< MD2_BLOCK_SIZE + 2;
101 t = (t + i) & 0xff, i++)
102 {
103 unsigned j;
104 for (j = 0; j < 3 * MD2_BLOCK_SIZE; j++)
105 t = (ctx->X[j] ^= S[t]);
106 }
107 }
108
109 void
md2_init(struct md2_ctx * ctx)110 md2_init(struct md2_ctx *ctx)
111 {
112 memset(ctx, 0, sizeof(*ctx));
113 }
114
115 void
md2_update(struct md2_ctx * ctx,size_t length,const uint8_t * data)116 md2_update(struct md2_ctx *ctx,
117 size_t length,
118 const uint8_t *data)
119 {
120 MD_UPDATE(ctx, length, data, md2_transform, (void)0);
121 }
122
123 void
md2_digest(struct md2_ctx * ctx,size_t length,uint8_t * digest)124 md2_digest(struct md2_ctx *ctx,
125 size_t length,
126 uint8_t *digest)
127 {
128 unsigned left;
129
130 assert(length <= MD2_DIGEST_SIZE);
131
132 left = MD2_BLOCK_SIZE - ctx->index;
133 memset(ctx->block + ctx->index, left, left);
134 md2_transform(ctx, ctx->block);
135
136 md2_transform(ctx, ctx->C);
137 memcpy(digest, ctx->X, length);
138 md2_init(ctx);
139 }
140