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d3187d77 | 1 | /* -*-c-*- |
2 | * | |
b817bfc6 | 3 | * $Id: md2.c,v 1.3 2004/04/08 01:36:15 mdw Exp $ |
d3187d77 | 4 | * |
5 | * The MD2 message digest function | |
6 | * | |
7 | * (c) 2001 Straylight/Edgeware | |
8 | */ | |
9 | ||
45c0fd36 | 10 | /*----- Licensing notice --------------------------------------------------* |
d3187d77 | 11 | * |
12 | * This file is part of Catacomb. | |
13 | * | |
14 | * Catacomb is free software; you can redistribute it and/or modify | |
15 | * it under the terms of the GNU Library General Public License as | |
16 | * published by the Free Software Foundation; either version 2 of the | |
17 | * License, or (at your option) any later version. | |
45c0fd36 | 18 | * |
d3187d77 | 19 | * Catacomb is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
22 | * GNU Library General Public License for more details. | |
45c0fd36 | 23 | * |
d3187d77 | 24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with Catacomb; if not, write to the Free | |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, | |
27 | * MA 02111-1307, USA. | |
28 | */ | |
29 | ||
d3187d77 | 30 | /*----- Header files ------------------------------------------------------*/ |
31 | ||
32 | #include <mLib/bits.h> | |
33 | ||
34 | #include "ghash.h" | |
35 | #include "ghash-def.h" | |
36 | #include "hash.h" | |
37 | #include "md2.h" | |
38 | #include "md2-tab.h" | |
39 | ||
40 | /*----- Tables ------------------------------------------------------------*/ | |
41 | ||
4e66da02 | 42 | static const octet s[256] = MD2_S; |
d3187d77 | 43 | |
44 | /*----- Main code ---------------------------------------------------------*/ | |
45 | ||
46 | /* --- @md2_compress@ --- * | |
47 | * | |
48 | * Arguments: @md2_ctx *ctx@ = pointer to context block | |
49 | * @const void *sbuf@ = pointer to buffer of appropriate size | |
50 | * | |
51 | * Returns: --- | |
52 | * | |
53 | * Use: MD2 compression and checksum function. | |
54 | */ | |
55 | ||
56 | void md2_compress(md2_ctx *ctx, const void *sbuf) | |
57 | { | |
58 | unsigned i; | |
59 | unsigned t; | |
60 | octet x[MD2_BUFSZ]; | |
61 | octet y[MD2_BUFSZ]; | |
62 | ||
63 | /* --- Handy macro for doing something lots of times --- */ | |
64 | ||
65 | #define DO(what, where) do { \ | |
45c0fd36 MW |
66 | what(where, 0); what(where, 1); what(where, 2); what(where, 3); \ |
67 | what(where, 4); what(where, 5); what(where, 6); what(where, 7); \ | |
68 | what(where, 8); what(where, 9); what(where, 10); what(where, 11); \ | |
d3187d77 | 69 | what(where, 12); what(where, 13); what(where, 14); what(where, 15); \ |
70 | } while (0) | |
71 | ||
72 | /* --- Do the hashing first to avoid corrupting the checksum --- */ | |
73 | ||
74 | memcpy(x, sbuf, sizeof(x)); | |
75 | #define X(z, i) y[i] = z[i] ^ ctx->h[i] | |
76 | DO(X, x); | |
77 | #undef X | |
78 | ||
79 | t = 0; | |
80 | for (i = 0; i < 18; i++) { | |
81 | #define X(z, i) t = z[i] ^= s[t]; | |
82 | DO(X, ctx->h); | |
83 | DO(X, x); | |
84 | DO(X, y); | |
85 | #undef X | |
86 | t = U8(t + i); | |
87 | } | |
88 | ||
89 | /* --- Now compute the checksum --- */ | |
90 | ||
91 | t = ctx->c[MD2_BUFSZ - 1]; | |
92 | #define X(z, i) t = ctx->c[i] ^= s[z[i] ^ t] | |
93 | DO(X, ((const octet *)sbuf)); | |
94 | #undef X | |
95 | ||
96 | #undef DO | |
97 | } | |
98 | ||
99 | /* --- @md2_init@ --- * | |
100 | * | |
101 | * Arguments: @md2_ctx *ctx@ = pointer to context block to initialize | |
102 | * | |
103 | * Returns: --- | |
104 | * | |
105 | * Use: Initializes a context block ready for hashing. | |
106 | */ | |
107 | ||
108 | void md2_init(md2_ctx *ctx) | |
109 | { | |
110 | memset(ctx->c, 0, sizeof(ctx->c)); | |
111 | memset(ctx->h, 0, sizeof(ctx->h)); | |
112 | ctx->off = 0; | |
113 | } | |
114 | ||
115 | /* --- @md2_set@ --- * | |
116 | * | |
117 | * Arguments: @md2_ctx *ctx@ = pointer to context block | |
118 | * @const void *buf@ = pointer to state buffer | |
119 | * @unsigned long count@ = current count of bytes processed | |
120 | * | |
121 | * Returns: --- | |
122 | * | |
123 | * Use: Initializes a context block from a given state. This is | |
124 | * useful in cases where the initial hash state is meant to be | |
125 | * secret, e.g., for NMAC and HMAC support. | |
126 | */ | |
127 | ||
128 | void md2_set(md2_ctx *ctx, const void *buf, unsigned long count) | |
129 | { | |
130 | const octet *p = buf; | |
131 | memcpy(ctx->h, p, MD2_BUFSZ); | |
132 | memcpy(ctx->c, p + MD2_BUFSZ, MD2_BUFSZ); | |
133 | ctx->off = 0; | |
134 | } | |
135 | ||
136 | /* --- @md2_hash@ --- * | |
137 | * | |
138 | * Arguments: @md2_ctx *ctx@ = pointer to context block | |
139 | * @const void *buf@ = buffer of data to hash | |
140 | * @size_t sz@ = size of buffer to hash | |
141 | * | |
142 | * Returns: --- | |
143 | * | |
144 | * Use: Hashes a buffer of data. The buffer may be of any size and | |
145 | * alignment. | |
146 | */ | |
147 | ||
148 | void md2_hash(md2_ctx *ctx, const void *buf, size_t sz) | |
149 | { | |
150 | const octet *bbuf = (octet *)buf; | |
151 | ||
152 | /* --- Code automatically expanded from @HASH_BUFFER@ and tidied --- */ | |
153 | ||
154 | if (ctx->off + sz < MD2_BUFSZ) { | |
155 | memcpy(ctx->buf + ctx->off, bbuf, sz); | |
156 | ctx->off += sz; | |
157 | } else { | |
158 | if (ctx->off) { | |
159 | size_t s = MD2_BUFSZ - ctx->off; | |
160 | memcpy(ctx->buf + ctx->off, bbuf, s); | |
161 | md2_compress(ctx, ctx->buf); | |
162 | sz -= s; | |
163 | bbuf += s; | |
164 | } | |
165 | while (sz >= MD2_BUFSZ) { | |
166 | md2_compress(ctx, bbuf); | |
167 | sz -= MD2_BUFSZ; bbuf += MD2_BUFSZ; | |
168 | } | |
169 | if (sz) | |
170 | memcpy(ctx->buf, bbuf, sz); | |
171 | ctx->off = sz; | |
172 | } | |
173 | } | |
174 | ||
175 | /* --- @md2_done@ --- * | |
176 | * | |
177 | * Arguments: @md2_ctx *ctx@ = pointer to context block | |
178 | * @void *hash@ = pointer to output buffer | |
179 | * | |
180 | * Returns: --- | |
181 | * | |
182 | * Use: Returns the hash of the data read so far. | |
183 | */ | |
184 | ||
185 | void md2_done(md2_ctx *ctx, void *hash) | |
186 | { | |
187 | unsigned pad = MD2_BUFSZ - ctx->off; | |
188 | unsigned i; | |
189 | for (i = ctx->off; i < MD2_BUFSZ; i++) | |
190 | ctx->buf[i] = pad; | |
191 | md2_compress(ctx, ctx->buf); | |
192 | md2_compress(ctx, ctx->c); | |
193 | memcpy(hash, ctx->h, MD2_BUFSZ); | |
194 | } | |
195 | ||
196 | /* --- @md2_state@ --- * | |
197 | * | |
198 | * Arguments: @md2_ctx *ctx@ = pointer to context | |
199 | * @void *state@ = pointer to buffer for current state | |
200 | * | |
201 | * Returns: Number of bytes written to the hash function so far. | |
202 | * | |
203 | * Use: Returns the current state of the hash function such that | |
204 | * it can be passed to @md2_set@. | |
205 | */ | |
206 | ||
207 | unsigned long md2_state(md2_ctx *ctx, void *state) | |
208 | { | |
209 | octet *p = state; | |
210 | memcpy(p, ctx->h, MD2_BUFSZ); | |
211 | memcpy(p + MD2_BUFSZ, ctx->c, MD2_BUFSZ); | |
212 | return (0); | |
213 | } | |
214 | ||
215 | /* --- Generic interface --- */ | |
216 | ||
217 | GHASH_DEF(MD2, md2) | |
218 | ||
219 | /* --- Test code --- */ | |
220 | ||
221 | HASH_TEST(MD2, md2) | |
222 | ||
223 | /*----- That's all, folks -------------------------------------------------*/ |