d03ab969 |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: hmac.h,v 1.1 1999/09/03 08:41:12 mdw Exp $ |
4 | * |
5 | * Generic code for HMAC and NMAC |
6 | * |
7 | * (c) 1998 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
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. |
18 | * |
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. |
23 | * |
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 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: hmac.h,v $ |
33 | * Revision 1.1 1999/09/03 08:41:12 mdw |
34 | * Initial import. |
35 | * |
36 | */ |
37 | |
38 | /*----- Notes on the HMAC and NMAC constructions --------------------------* |
39 | * |
40 | * Designed by Mihir Bellare, Ran Canetti and Hugo Krawczyk, NMAC is a |
41 | * method for constructing keyed message authentication algorithms from |
42 | * unkeyed hash functions. HMAC is an alternative formulation which doesn't |
43 | * require low-level access to the hash function's implementation. NMAC was |
44 | * designed to allow MD5 has a suitable underlying hash function, even though |
45 | * doubts were already being raised about its collision resistance. |
46 | */ |
47 | |
48 | #ifndef HMAC_H |
49 | #define HMAC_H |
50 | |
51 | #ifdef __cplusplus |
52 | extern "C" { |
53 | #endif |
54 | |
55 | /*----- Header files ------------------------------------------------------*/ |
56 | |
57 | #include <stdlib.h> |
58 | #include <string.h> |
59 | |
60 | #include <mLib/bits.h> |
61 | |
62 | #ifndef PARANOIA_H |
63 | # include "paranoia.h" |
64 | #endif |
65 | |
66 | /*----- Macros ------------------------------------------------------------*/ |
67 | |
68 | /* --- @HMAC_DECL@ --- * |
69 | * |
70 | * Arguments: @PRE@, @pre@ = prefixes for the underlying hash function |
71 | * |
72 | * Use: Creates declarations for the HMAC and NMAC functions. |
73 | */ |
74 | |
75 | #define HMAC_DECL(PRE, pre) \ |
76 | \ |
77 | typedef struct pre##_mackey { \ |
78 | octet ochain[PRE##_HASHSZ]; /* Chaining for outer hash */ \ |
79 | unsigned long ocount; /* Byte count for outer hash */ \ |
80 | octet ichain[PRE##_HASHSZ]; /* Chaining for inner hash */ \ |
81 | unsigned long icount; /* Byte count for inner hash */ \ |
82 | } pre##_mackey; \ |
83 | \ |
84 | typedef struct pre##_macctx { \ |
85 | pre##_ctx ctx; /* Context for main hashing */ \ |
86 | octet chain[PRE##_HASHSZ]; /* Chaining for outer hash */ \ |
87 | unsigned long count; /* Byte count for outer hash */ \ |
88 | } pre##_macctx; \ |
89 | \ |
90 | extern void pre##_nmac(pre##_mackey */*key*/, \ |
91 | const void */*ok*/, const void */*ik*/); \ |
92 | \ |
93 | extern void pre##_hmac(pre##_mackey */*key*/, \ |
94 | const void */*k*/, size_t /*sz*/); \ |
95 | \ |
96 | extern void pre##_macinit(pre##_macctx */*ctx*/, \ |
97 | const pre##_mackey */*key*/); \ |
98 | \ |
99 | extern void pre##_mac(pre##_macctx */*ctx*/, \ |
100 | const void */*buf*/, size_t /*sz*/); \ |
101 | \ |
102 | extern void pre##_macdone(pre##_macctx */*ctx*/, void */*mac*/); |
103 | |
104 | /* --- @HMAC_DEF@ --- * |
105 | * |
106 | * Arguments: @PRE@, @pre@ = prefixes for the underlying hash function |
107 | * |
108 | * Use: Creates implementations for the HMAC and NMAC functions. |
109 | */ |
110 | |
111 | #define HMAC_DEF(PRE, pre) \ |
112 | \ |
113 | /* --- @pre_nmac@ --- * \ |
114 | * \ |
115 | * Arguments: @pre_macctx *key@ = pointer to a MAC key object \ |
116 | * @const void *ok@ = pointer to outer hash init vector \ |
117 | * @const void *ik@ = pointer to inner hash init vector \ |
118 | * \ |
119 | * Returns: --- \ |
120 | * \ |
121 | * Use: Initializes a MAC key for doing NMAC hashing. \ |
122 | */ \ |
123 | \ |
124 | void pre##_nmac(pre##_mackey *key, const void *ok, const void *ik) \ |
125 | { \ |
126 | memcpy(key->ochain, ok, PRE##_HASHSZ); \ |
127 | memcpy(key->ichain, ik, PRE##_HASHSZ); \ |
128 | key->ocount = key->icount = 0; \ |
129 | } \ |
130 | \ |
131 | /* --- @pre_hmac@ --- * \ |
132 | * \ |
133 | * Arguments: @pre_mackey *key@ = pointer to MAC key object \ |
134 | * @const void *k@ = pointer to key to use \ |
135 | * @size_t sz@ = size of key data \ |
136 | * \ |
137 | * Returns: --- \ |
138 | * \ |
139 | * Use: Initializes a MAC key for doing HMAC hashing. Keys \ |
140 | * longer than the hash function's output size aren't very \ |
141 | * useful, but are accepted. Keys longer than the hash's \ |
142 | * block size are also accepted; they are hashed before \ |
143 | * use, as specified in RFC2104. \ |
144 | */ \ |
145 | \ |
146 | void pre##_hmac(pre##_mackey *key, const void *k, size_t sz) \ |
147 | { \ |
148 | int i; \ |
149 | const octet *kbuf = k; \ |
150 | pre##_ctx ctx; \ |
151 | octet buf[PRE##_HASHSZ]; \ |
152 | \ |
153 | if (sz > PRE##_BUFSZ) { \ |
154 | pre##_init(&ctx); \ |
155 | pre##_hash(&ctx, k, sz); \ |
156 | pre##_done(&ctx, buf); \ |
157 | kbuf = buf; \ |
158 | sz = PRE##_HASHSZ; \ |
159 | } \ |
160 | \ |
161 | pre##_init(&ctx); \ |
162 | memset(ctx.buf, 0x5c, PRE##_BUFSZ); \ |
163 | for (i = 0; i < sz; i++) \ |
164 | ctx.buf[i] ^= kbuf[i]; \ |
165 | pre##_compress(&ctx, ctx.buf); \ |
166 | pre##_state(&ctx, key->ochain); \ |
167 | \ |
168 | pre##_init(&ctx); \ |
169 | memset(ctx.buf, 0x36, PRE##_BUFSZ); \ |
170 | for (i = 0; i < sz; i++) \ |
171 | ctx.buf[i] ^= kbuf[i]; \ |
172 | pre##_compress(&ctx, ctx.buf); \ |
173 | pre##_state(&ctx, key->ichain); \ |
174 | \ |
175 | key->ocount = key->icount = PRE##_BUFSZ; \ |
176 | BURN(ctx); \ |
177 | } \ |
178 | \ |
179 | /* --- @pre_macinit@ --- * \ |
180 | * \ |
181 | * Arguments: @pre_macctx *ctx@ = pointer to MAC context block \ |
182 | * @const pre_mackey *key@ = pointer to MAC key block \ |
183 | * \ |
184 | * Returns: --- \ |
185 | * \ |
186 | * Use: Instantiates a MAC context from a key block. \ |
187 | */ \ |
188 | \ |
189 | void pre##_macinit(pre##_macctx *ctx, const pre##_mackey *key) \ |
190 | { \ |
191 | memcpy(ctx->chain, key->ochain, PRE##_HASHSZ); \ |
192 | ctx->count = key->ocount; \ |
193 | pre##_set(&ctx->ctx, key->ichain, key->icount); \ |
194 | } \ |
195 | \ |
196 | /* --- @pre_mac@ --- * \ |
197 | * \ |
198 | * Arguments: @pre_macctx *ctx@ = pointer to MAC context block \ |
199 | * @const void *buf@ = pointer to buffer \ |
200 | * @size_t sz@ = size of the buffer \ |
201 | * \ |
202 | * Returns: --- \ |
203 | * \ |
204 | * Use: Hashes a buffer. \ |
205 | */ \ |
206 | \ |
207 | void pre##_mac(pre##_macctx *ctx, const void *buf, size_t sz) \ |
208 | { \ |
209 | pre##_hash(&ctx->ctx, buf, sz); \ |
210 | } \ |
211 | \ |
212 | /* --- @pre_macdone@ --- * \ |
213 | * \ |
214 | * Arguments: @pre_macctx *ctx@ = pointer to MAC context block \ |
215 | * @void *mac@ = pointer to buffer to receive MAC \ |
216 | * \ |
217 | * Returns: --- \ |
218 | * \ |
219 | * Use: Returns the result of a MAC computation. \ |
220 | */ \ |
221 | \ |
222 | void pre##_macdone(pre##_macctx *ctx, void *mac) \ |
223 | { \ |
224 | pre##_done(&ctx->ctx, mac); \ |
225 | pre##_set(&ctx->ctx, ctx->chain, ctx->count); \ |
226 | pre##_hash(&ctx->ctx, mac, PRE##_HASHSZ); \ |
227 | pre##_done(&ctx->ctx, mac); \ |
228 | } \ |
229 | \ |
230 | HMAC_TEST(PRE, pre) \ |
231 | |
232 | /* --- @HMAC_TEST@ --- * |
233 | * |
234 | * Arguments: @PRE@, @pre@ = prefixes for hash-specfic definitions |
235 | * |
236 | * Use: Standard test rig for MAC functions. |
237 | */ |
238 | |
239 | #ifdef TEST_RIG |
240 | |
241 | #include <mLib/dstr.h> |
242 | #include <mLib/quis.h> |
243 | #include <mLib/testrig.h> |
244 | |
245 | #define HMAC_TEST(PRE, pre) \ |
246 | \ |
247 | static int macverify(dstr *v) \ |
248 | { \ |
249 | pre##_macctx cctx; \ |
250 | pre##_mackey ckey; \ |
251 | int ok = 1; \ |
252 | int i; \ |
253 | octet *p; \ |
254 | int szs[] = { 1, 7, 192, -1, 0 }, *ip; \ |
255 | size_t csz; \ |
256 | dstr d; \ |
257 | \ |
258 | dstr_create(&d); \ |
259 | dstr_ensure(&d, PRE##_HASHSZ); \ |
260 | d.len = PRE##_HASHSZ; \ |
261 | \ |
262 | pre##_hmac(&ckey, v[1].buf, v[1].len); \ |
263 | \ |
264 | for (ip = szs; *ip; ip++) { \ |
265 | i = *ip; \ |
266 | csz = v[0].len; \ |
267 | if (i == -1) \ |
268 | i = csz; \ |
269 | if (i > csz) \ |
270 | continue; \ |
271 | p = (octet *)v[0].buf; \ |
272 | pre##_macinit(&cctx, &ckey); \ |
273 | while (csz) { \ |
274 | if (i > csz) \ |
275 | i = csz; \ |
276 | pre##_mac(&cctx, p, i); \ |
277 | p += i; \ |
278 | csz -= i; \ |
279 | } \ |
280 | pre##_macdone(&cctx, d.buf); \ |
281 | if (memcmp(d.buf, v[2].buf, PRE##_HASHSZ) != 0) { \ |
282 | printf("\nfail:\n\tstep = %i\n\tinput = `%s'\n\tkey = ", \ |
283 | *ip, v[0].buf); \ |
284 | type_hex.dump(&v[1], stdout); \ |
285 | fputs("\n\texpected = ", stdout); \ |
286 | type_hex.dump(&v[2], stdout); \ |
287 | fputs("\n\tcomputed = ", stdout); \ |
288 | type_hex.dump(&d, stdout); \ |
289 | putchar('\n'); \ |
290 | ok = 0; \ |
291 | } \ |
292 | } \ |
293 | \ |
294 | dstr_destroy(&d); \ |
295 | return (ok); \ |
296 | } \ |
297 | \ |
298 | static test_chunk macdefs[] = { \ |
299 | { #pre "-hmac", macverify, \ |
300 | { &type_string, &type_hex, &type_hex, 0 } }, \ |
301 | { 0, 0, { 0 } } \ |
302 | }; \ |
303 | \ |
304 | int main(int argc, char *argv[]) \ |
305 | { \ |
306 | ego(argv[0]); \ |
307 | test_run(argc, argv, macdefs, SRCDIR"/tests/" #pre); \ |
308 | return (0); \ |
309 | } |
310 | |
311 | #else |
312 | # define HMAC_TEST(PRE, pre) |
313 | #endif |
314 | |
315 | /*----- That's all, folks -------------------------------------------------*/ |
316 | |
317 | #ifdef __cplusplus |
318 | } |
319 | #endif |
320 | |
321 | #endif |