410c8acf |
1 | /* -*-c-*- |
2 | * |
9466fafa |
3 | * $Id: keyexch.c,v 1.6 2003/04/06 10:26:35 mdw Exp $ |
410c8acf |
4 | * |
5 | * Key exchange protocol |
6 | * |
7 | * (c) 2001 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Trivial IP Encryption (TrIPE). |
13 | * |
14 | * TrIPE is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2 of the License, or |
17 | * (at your option) any later version. |
18 | * |
19 | * TrIPE 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 General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU General Public License |
25 | * along with TrIPE; if not, write to the Free Software Foundation, |
26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
27 | */ |
28 | |
29 | /*----- Revision history --------------------------------------------------* |
30 | * |
31 | * $Log: keyexch.c,v $ |
9466fafa |
32 | * Revision 1.6 2003/04/06 10:26:35 mdw |
33 | * Report peer name on decrypt errors. |
34 | * |
5d418e24 |
35 | * Revision 1.5 2002/01/13 14:54:40 mdw |
36 | * Patch up zero-knowledge property by passing an encrypted log with a |
37 | * challenge, so that the prover can verify that the challenge is good. |
38 | * |
00e64b67 |
39 | * Revision 1.4 2001/06/22 19:40:36 mdw |
40 | * Support expiry of other peers' public keys. |
41 | * |
56814747 |
42 | * Revision 1.3 2001/06/19 22:07:09 mdw |
43 | * Cosmetic fixes. |
44 | * |
0617b6e7 |
45 | * Revision 1.2 2001/02/16 21:24:27 mdw |
46 | * Rewrite for new key exchange protocol. |
47 | * |
410c8acf |
48 | * Revision 1.1 2001/02/03 20:26:37 mdw |
49 | * Initial checkin. |
50 | * |
51 | */ |
52 | |
53 | /*----- Header files ------------------------------------------------------*/ |
54 | |
55 | #include "tripe.h" |
56 | |
57 | /*----- Tunable parameters ------------------------------------------------*/ |
58 | |
59 | #define T_VALID MIN(2) |
410c8acf |
60 | #define T_RETRY SEC(10) |
410c8acf |
61 | |
0617b6e7 |
62 | #define ISVALID(kx, now) ((now) < (kx)->t_valid) |
63 | |
64 | /*----- Various utilities -------------------------------------------------*/ |
410c8acf |
65 | |
66 | /* --- @hashmp@ --- * |
67 | * |
0617b6e7 |
68 | * Arguments: @HASH_CTX *r@ = pointer to hash context |
410c8acf |
69 | * @mp *m@ = pointer to multiprecision integer |
70 | * |
71 | * Returns: --- |
72 | * |
73 | * Use: Adds the hash of a multiprecision integer to the context. |
0617b6e7 |
74 | * Corrupts @buf_t@. |
410c8acf |
75 | */ |
76 | |
0617b6e7 |
77 | static void hashmp(HASH_CTX *r, mp *m) |
410c8acf |
78 | { |
79 | buf b; |
0617b6e7 |
80 | buf_init(&b, buf_t, sizeof(buf_t)); |
410c8acf |
81 | buf_putmp(&b, m); |
82 | assert(BOK(&b)); |
0617b6e7 |
83 | HASH(r, BBASE(&b), BLEN(&b)); |
410c8acf |
84 | } |
85 | |
5d418e24 |
86 | /* --- @mpcrypt@ --- * |
87 | * |
88 | * Arguments: @mp *d@ = the destination integer |
89 | * @mp *x@ = the plaintext/ciphertext integer |
90 | * @size_t sz@ = the expected size of the plaintext |
91 | * @const octet *k@ = pointer to key material |
92 | * @size_t ksz@ = size of the key |
93 | * |
94 | * Returns: The encrypted/decrypted integer. |
95 | * |
96 | * Use: Encrypts (or decrypts) a multiprecision integer using another |
97 | * multiprecision integer as the key. This is a slightly grotty |
98 | * way to do this, but it's easier than the alternatives. |
99 | */ |
100 | |
101 | static mp *mpcrypt(mp *d, mp *x, size_t sz, const octet *k, size_t ksz) |
102 | { |
103 | MGF_CTX m; |
104 | |
105 | MGF_INIT(&m, k, ksz, 0); |
106 | mp_storeb(x, buf_t, sz); |
107 | MGF_CRYPT(&m, buf_t, buf_t, sz); |
108 | return (mp_loadb(d, buf_t, sz)); |
109 | } |
110 | |
410c8acf |
111 | /* --- @timer@ --- * |
112 | * |
113 | * Arguments: @struct timeval *tv@ = the current time |
114 | * @void *v@ = pointer to key exchange context |
115 | * |
116 | * Returns: --- |
117 | * |
118 | * Use: Acts when the key exchange timer goes off. |
119 | */ |
120 | |
121 | static void timer(struct timeval *tv, void *v) |
122 | { |
123 | keyexch *kx = v; |
124 | kx->f &= ~KXF_TIMER; |
125 | T( trace(T_KEYEXCH, "keyexch: timer has popped"); ) |
126 | kx_start(kx); |
127 | } |
128 | |
129 | /* --- @settimer@ --- * |
130 | * |
131 | * Arguments: @keyexch *kx@ = pointer to key exchange context |
132 | * @time_t t@ = when to set the timer for |
133 | * |
134 | * Returns: --- |
135 | * |
136 | * Use: Sets the timer for the next key exchange attempt. |
137 | */ |
138 | |
139 | static void settimer(keyexch *kx, time_t t) |
140 | { |
141 | struct timeval tv; |
142 | if (kx->f & KXF_TIMER) |
143 | sel_rmtimer(&kx->t); |
144 | tv.tv_sec = t; |
145 | tv.tv_usec = 0; |
146 | sel_addtimer(&sel, &kx->t, &tv, timer, kx); |
147 | kx->f |= KXF_TIMER; |
148 | } |
149 | |
0617b6e7 |
150 | /*----- Challenge management ----------------------------------------------*/ |
151 | |
152 | /* --- Notes on challenge management --- * |
410c8acf |
153 | * |
0617b6e7 |
154 | * We may get multiple different replies to our key exchange; some will be |
155 | * correct, some inserted by attackers. Up until @KX_THRESH@, all challenges |
156 | * received will be added to the table and given a full response. After |
157 | * @KX_THRESH@ distinct challenges are received, we return only a `cookie': |
158 | * our existing challenge, followed by a hash of the sender's challenge. We |
159 | * do %%\emph{not}%% give a bare challenge a reply slot at this stage. All |
160 | * properly-formed cookies are assigned a table slot: if none is spare, a |
161 | * used slot is randomly selected and destroyed. A cookie always receives a |
162 | * full reply. |
163 | */ |
164 | |
165 | /* --- @kxc_destroy@ --- * |
166 | * |
167 | * Arguments: @kxchal *kxc@ = pointer to the challenge block |
410c8acf |
168 | * |
169 | * Returns: --- |
170 | * |
0617b6e7 |
171 | * Use: Disposes of a challenge block. |
410c8acf |
172 | */ |
173 | |
0617b6e7 |
174 | static void kxc_destroy(kxchal *kxc) |
410c8acf |
175 | { |
0617b6e7 |
176 | if (kxc->f & KXF_TIMER) |
177 | sel_rmtimer(&kxc->t); |
178 | mp_drop(kxc->c); |
179 | mp_drop(kxc->r); |
5d418e24 |
180 | mp_drop(kxc->ck); |
0617b6e7 |
181 | ks_drop(kxc->ks); |
182 | DESTROY(kxc); |
183 | } |
410c8acf |
184 | |
0617b6e7 |
185 | /* --- @kxc_stoptimer@ --- * |
186 | * |
187 | * Arguments: @kxchal *kxc@ = pointer to the challenge block |
188 | * |
189 | * Returns: --- |
190 | * |
191 | * Use: Stops the challenge's retry timer from sending messages. |
192 | * Useful when the state machine is in the endgame of the |
193 | * exchange. |
194 | */ |
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195 | |
0617b6e7 |
196 | static void kxc_stoptimer(kxchal *kxc) |
197 | { |
198 | if (kxc->f & KXF_TIMER) |
199 | sel_rmtimer(&kxc->t); |
200 | } |
410c8acf |
201 | |
0617b6e7 |
202 | /* --- @kxc_new@ --- * |
203 | * |
204 | * Arguments: @keyexch *kx@ = pointer to key exchange block |
0617b6e7 |
205 | * |
206 | * Returns: A pointer to the challenge block. |
207 | * |
208 | * Use: Returns a pointer to a new challenge block to fill in. |
209 | */ |
410c8acf |
210 | |
0617b6e7 |
211 | static kxchal *kxc_new(keyexch *kx) |
212 | { |
213 | kxchal *kxc; |
214 | unsigned i; |
215 | |
216 | /* --- If we're over reply threshold, discard one at random --- */ |
217 | |
218 | if (kx->nr < KX_NCHAL) |
219 | i = kx->nr++; |
220 | else { |
221 | i = rand_global.ops->range(&rand_global, KX_NCHAL); |
222 | kxc_destroy(kx->r[i]); |
410c8acf |
223 | } |
224 | |
0617b6e7 |
225 | /* --- Fill in the new structure --- */ |
410c8acf |
226 | |
0617b6e7 |
227 | kxc = CREATE(kxchal); |
228 | kxc->c = 0; |
229 | kxc->r = 0; |
5d418e24 |
230 | kxc->ck = 0; |
0617b6e7 |
231 | kxc->ks = 0; |
232 | kxc->kx = kx; |
233 | kxc->f = 0; |
234 | kx->r[i] = kxc; |
235 | return (kxc); |
236 | } |
410c8acf |
237 | |
0617b6e7 |
238 | /* --- @kxc_bychal@ --- * |
239 | * |
240 | * Arguments: @keyexch *kx@ = pointer to key exchange block |
241 | * @mp *c@ = challenge from remote host |
242 | * |
243 | * Returns: Pointer to the challenge block, or null. |
244 | * |
245 | * Use: Finds a challenge block, given its challenge. |
246 | */ |
247 | |
248 | static kxchal *kxc_bychal(keyexch *kx, mp *c) |
249 | { |
250 | unsigned i; |
251 | |
252 | for (i = 0; i < kx->nr; i++) { |
253 | if (MP_EQ(c, kx->r[i]->c)) |
254 | return (kx->r[i]); |
255 | } |
256 | return (0); |
257 | } |
258 | |
259 | /* --- @kxc_byhc@ --- * |
260 | * |
261 | * Arguments: @keyexch *kx@ = pointer to key exchange block |
262 | * @const octet *hc@ = challenge hash from remote host |
263 | * |
264 | * Returns: Pointer to the challenge block, or null. |
265 | * |
266 | * Use: Finds a challenge block, given a hash of its challenge. |
267 | */ |
410c8acf |
268 | |
0617b6e7 |
269 | static kxchal *kxc_byhc(keyexch *kx, const octet *hc) |
270 | { |
271 | unsigned i; |
272 | |
273 | for (i = 0; i < kx->nr; i++) { |
274 | if (memcmp(hc, kx->r[i]->hc, HASHSZ) == 0) |
275 | return (kx->r[i]); |
410c8acf |
276 | } |
0617b6e7 |
277 | return (0); |
278 | } |
279 | |
280 | /* --- @kxc_answer@ --- * |
281 | * |
282 | * Arguments: @keyexch *kx@ = pointer to key exchange block |
283 | * @kxchal *kxc@ = pointer to challenge block |
284 | * |
285 | * Returns: --- |
286 | * |
287 | * Use: Sends a reply to the remote host, according to the data in |
288 | * this challenge block. |
289 | */ |
290 | |
291 | static void kxc_answer(keyexch *kx, kxchal *kxc); |
292 | |
293 | static void kxc_timer(struct timeval *tv, void *v) |
294 | { |
295 | kxchal *kxc = v; |
296 | kxc->f &= ~KXF_TIMER; |
297 | kxc_answer(kxc->kx, kxc); |
298 | } |
299 | |
300 | static void kxc_answer(keyexch *kx, kxchal *kxc) |
301 | { |
302 | stats *st = p_stats(kx->p); |
303 | buf *b = p_txstart(kx->p, MSG_KEYEXCH | (kxc->r ? KX_REPLY : KX_CHAL)); |
304 | struct timeval tv; |
305 | buf bb; |
306 | |
307 | /* --- Build the reply packet --- */ |
308 | |
309 | if (!kxc->r) |
310 | buf_putmp(b, kx->c); |
311 | else |
312 | buf_put(b, kx->hc, HASHSZ); |
313 | buf_put(b, kxc->hc, HASHSZ); |
5d418e24 |
314 | buf_putmp(b, kxc->ck); |
0617b6e7 |
315 | |
316 | /* --- Maybe send an actual reply, if we have one --- */ |
410c8acf |
317 | |
0617b6e7 |
318 | if (!kxc->r) { |
319 | T( trace(T_KEYEXCH, "keyexch: resending challenge to `%s'", |
320 | p_name(kx->p)); ) |
321 | } else { |
322 | T( trace(T_KEYEXCH, "keyexch: sending reply to `%s'", p_name(kx->p)); ) |
323 | buf_init(&bb, buf_i, sizeof(buf_i)); |
324 | buf_putmp(&bb, kxc->r); |
325 | buf_flip(&bb); |
326 | ks_encrypt(kxc->ks, &bb, b); |
327 | } |
328 | |
329 | /* --- Update the statistics --- */ |
330 | |
331 | if (BOK(b)) { |
332 | st->n_kxout++; |
333 | st->sz_kxout += BLEN(b); |
334 | p_txend(kx->p); |
335 | } |
336 | |
337 | /* --- Schedule another resend --- */ |
338 | |
339 | if (kxc->f & KXF_TIMER) |
340 | sel_rmtimer(&kxc->t); |
341 | gettimeofday(&tv, 0); |
342 | tv.tv_sec += T_RETRY; |
343 | sel_addtimer(&sel, &kxc->t, &tv, kxc_timer, kxc); |
344 | kxc->f |= KXF_TIMER; |
345 | } |
346 | |
347 | /*----- Individual message handlers ---------------------------------------*/ |
348 | |
349 | /* --- @getreply@ --- * |
350 | * |
351 | * Arguments: @keyexch *kx@ = pointer to key exchange context |
352 | * @mp *c@ = a challenge |
5d418e24 |
353 | * @mp *ck@ = the supplied expected-reply check value |
0617b6e7 |
354 | * |
355 | * Returns: A pointer to the reply, or null if the reply-hash was wrong. |
356 | * |
357 | * Use: Computes replies to challenges. |
358 | */ |
359 | |
5d418e24 |
360 | static mp *getreply(keyexch *kx, mp *c, mp *ck) |
0617b6e7 |
361 | { |
362 | mp *r = mpmont_exp(&mg, MP_NEW, c, kpriv.x); |
5d418e24 |
363 | mp *a; |
0617b6e7 |
364 | HASH_CTX h; |
5d418e24 |
365 | octet buf[HASHSZ]; |
366 | int ok; |
0617b6e7 |
367 | |
368 | HASH_INIT(&h); |
369 | HASH_STRING(&h, "tripe-expected-reply"); |
370 | hashmp(&h, c); |
371 | hashmp(&h, kx->c); |
372 | hashmp(&h, r); |
373 | HASH_DONE(&h, buf); |
5d418e24 |
374 | |
375 | a = mpcrypt(MP_NEW, ck, mp_octets(kpriv.dp.q), buf, sizeof(buf)); |
0617b6e7 |
376 | IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, { |
377 | trace(T_CRYPTO, "crypto: computed reply = %s", mpstr(r)); |
378 | trace_block(T_CRYPTO, "crypto: computed reply hash", buf, HASHSZ); |
5d418e24 |
379 | trace(T_CRYPTO, "crypto: recovered log = %s", mpstr(a)); |
0617b6e7 |
380 | })) |
5d418e24 |
381 | a = mpmont_exp(&mg, a, kpriv.dp.g, a); |
382 | ok = mp_eq(a, c); |
383 | if (!ok) { |
384 | a_warn("invalid expected-reply check from `%s'", p_name(kx->p)); |
385 | IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, { |
386 | trace(T_CRYPTO, "crypto: computed challenge = %s", mpstr(a)); |
387 | })) |
0617b6e7 |
388 | mp_drop(r); |
0617b6e7 |
389 | } |
5d418e24 |
390 | mp_drop(a); |
391 | return (ok ? r : 0); |
0617b6e7 |
392 | } |
393 | |
394 | /* --- @dochallenge@ --- * |
395 | * |
396 | * Arguments: @keyexch *kx@ = pointer to key exchange block |
397 | * @unsigned msg@ = message code for the packet |
398 | * @buf *b@ = buffer containing the packet |
399 | * |
400 | * Returns: Zero if OK, nonzero if the packet was rejected. |
401 | * |
402 | * Use: Processes a packet containing a challenge. |
403 | */ |
404 | |
405 | static int dochallenge(keyexch *kx, unsigned msg, buf *b) |
406 | { |
5d418e24 |
407 | mp *c = 0, *ck = 0; |
408 | const octet *hc = 0; |
0617b6e7 |
409 | kxchal *kxc; |
410 | HASH_CTX h; |
5d418e24 |
411 | octet buf[HASHSZ]; |
0617b6e7 |
412 | |
413 | /* --- Ensure that we're in a sensible state --- */ |
414 | |
415 | if (kx->s != KXS_CHAL) { |
416 | a_warn("unexpected challenge from `%s'", p_name(kx->p)); |
417 | goto bad; |
418 | } |
419 | |
420 | /* --- Unpack the packet --- */ |
421 | |
422 | if ((c = buf_getmp(b)) == 0 || |
423 | (msg >= KX_COOKIE && (hc = buf_get(b, HASHSZ)) == 0) || |
5d418e24 |
424 | (msg >= KX_CHAL && (ck = buf_getmp(b)) == 0) || |
0617b6e7 |
425 | BLEFT(b)) { |
426 | a_warn("malformed packet from `%s'", p_name(kx->p)); |
427 | goto bad; |
428 | } |
429 | |
430 | IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, { |
431 | trace(T_CRYPTO, "crypto: challenge = %s", mpstr(c)); |
432 | if (hc) trace_block(T_CRYPTO, "crypto: cookie", hc, HASHSZ); |
5d418e24 |
433 | if (ck) trace(T_CRYPTO, "crypto: check value = %s", mpstr(ck)); |
0617b6e7 |
434 | })) |
435 | |
436 | /* --- First, handle a bare challenge --- * |
437 | * |
438 | * If the table is heavily loaded, just emit a cookie and return. |
439 | */ |
440 | |
441 | if (!hc && kx->nr >= KX_THRESH) { |
442 | T( trace(T_KEYEXCH, "keyexch: too many challenges -- sending cookie"); ) |
443 | b = p_txstart(kx->p, MSG_KEYEXCH | KX_COOKIE); |
444 | buf_putmp(b, kx->c); |
445 | HASH_INIT(&h); |
446 | HASH_STRING(&h, "tripe-cookie"); |
447 | hashmp(&h, c); |
448 | HASH_DONE(&h, buf_get(b, HASHSZ)); |
449 | p_txend(kx->p); |
450 | goto tidy; |
451 | } |
452 | |
453 | /* --- Discard a packet with an invalid cookie --- */ |
454 | |
455 | if (hc && memcmp(hc, kx->hc, HASHSZ) != 0) { |
456 | a_warn("incorrect cookie from `%s'", p_name(kx->p)); |
457 | goto bad; |
458 | } |
459 | |
460 | /* --- Find a challenge block for this packet --- * |
410c8acf |
461 | * |
0617b6e7 |
462 | * If there isn't one already, create a new one. |
410c8acf |
463 | */ |
464 | |
0617b6e7 |
465 | if ((kxc = kxc_bychal(kx, c)) == 0) { |
466 | size_t x, y, z; |
467 | mp *r; |
468 | |
469 | /* --- Be careful here --- * |
470 | * |
471 | * If this is a full challenge, and it's the first time I've seen it, I |
472 | * want to be able to throw it away before committing a table entry to |
473 | * it. |
474 | */ |
475 | |
5d418e24 |
476 | if (!ck) |
0617b6e7 |
477 | kxc = kxc_new(kx); |
478 | else { |
5d418e24 |
479 | if ((r = getreply(kx, c, ck)) == 0) |
0617b6e7 |
480 | goto bad; |
481 | kxc = kxc_new(kx); |
482 | kxc->r = r; |
410c8acf |
483 | } |
0617b6e7 |
484 | kxc->c = mp_copy(c); |
485 | |
486 | /* --- Work out the cookie for this challenge --- */ |
487 | |
488 | HASH_INIT(&h); |
489 | HASH_STRING(&h, "tripe-cookie"); |
490 | hashmp(&h, kxc->c); |
491 | HASH_DONE(&h, kxc->hc); |
492 | |
493 | /* --- Compute the expected-reply hash --- */ |
494 | |
495 | HASH_INIT(&h); |
496 | HASH_STRING(&h, "tripe-expected-reply"); |
497 | hashmp(&h, kx->c); |
498 | hashmp(&h, kxc->c); |
499 | hashmp(&h, kx->rx); |
5d418e24 |
500 | HASH_DONE(&h, buf); |
501 | kxc->ck = mpcrypt(MP_NEW, kx->alpha, mp_octets(kpriv.dp.q), |
502 | buf, sizeof(buf)); |
0617b6e7 |
503 | |
504 | /* --- Work out the shared key --- */ |
505 | |
5d418e24 |
506 | trace(T_CRYPTO, "debug: c = %s", mpstr(c)); |
507 | trace(T_CRYPTO, "debug: alpha = %s", mpstr(kx->alpha)); |
0617b6e7 |
508 | r = mpmont_exp(&mg, MP_NEW, c, kx->alpha); |
5d418e24 |
509 | trace(T_CRYPTO, "debug: r = %s", mpstr(r)); |
0617b6e7 |
510 | |
511 | /* --- Compute the switch messages --- */ |
512 | |
513 | HASH_INIT(&h); HASH_STRING(&h, "tripe-switch-request"); |
514 | hashmp(&h, kx->c); hashmp(&h, kxc->c); |
515 | HASH_DONE(&h, kxc->hswrq_out); |
516 | HASH_INIT(&h); HASH_STRING(&h, "tripe-switch-confirm"); |
517 | hashmp(&h, kx->c); hashmp(&h, kxc->c); |
518 | HASH_DONE(&h, kxc->hswok_out); |
519 | |
520 | HASH_INIT(&h); HASH_STRING(&h, "tripe-switch-request"); |
521 | hashmp(&h, kxc->c); hashmp(&h, kx->c); |
522 | HASH_DONE(&h, kxc->hswrq_in); |
523 | HASH_INIT(&h); HASH_STRING(&h, "tripe-switch-confirm"); |
524 | hashmp(&h, kxc->c); hashmp(&h, kx->c); |
525 | HASH_DONE(&h, kxc->hswok_in); |
526 | |
527 | IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, { |
528 | trace_block(T_CRYPTO, "crypto: computed cookie", kxc->hc, HASHSZ); |
5d418e24 |
529 | trace_block(T_CRYPTO, "crypto: expected-reply hash", |
530 | buf, HASHSZ); |
531 | trace(T_CRYPTO, "crypto: my reply check = %s", mpstr(kxc->ck)); |
0617b6e7 |
532 | trace(T_CRYPTO, "crypto: shared secret = %s", mpstr(r)); |
533 | trace_block(T_CRYPTO, "crypto: outbound switch request", |
534 | kxc->hswrq_out, HASHSZ); |
535 | trace_block(T_CRYPTO, "crypto: outbound switch confirm", |
536 | kxc->hswok_out, HASHSZ); |
537 | trace_block(T_CRYPTO, "crypto: inbound switch request", |
538 | kxc->hswrq_in, HASHSZ); |
539 | trace_block(T_CRYPTO, "crypto: inbound switch confirm", |
540 | kxc->hswok_in, HASHSZ); |
541 | })) |
542 | |
543 | /* --- Create a new symmetric keyset --- */ |
544 | |
545 | buf_init(b, buf_o, sizeof(buf_o)); |
546 | buf_putmp(b, kx->c); x = BLEN(b); |
547 | buf_putmp(b, kxc->c); y = BLEN(b); |
548 | buf_putmp(b, r); z = BLEN(b); |
549 | assert(BOK(b)); |
550 | |
9466fafa |
551 | kxc->ks = ks_gen(BBASE(b), x, y, z, kx->p); |
0617b6e7 |
552 | mp_drop(r); |
410c8acf |
553 | } |
554 | |
0617b6e7 |
555 | /* --- Answer the challenge if we need to --- */ |
410c8acf |
556 | |
5d418e24 |
557 | if (ck && !kxc->r) { |
0617b6e7 |
558 | mp *r; |
5d418e24 |
559 | if ((r = getreply(kx, c, ck)) == 0) |
0617b6e7 |
560 | goto bad; |
561 | kxc->r = r; |
410c8acf |
562 | } |
0617b6e7 |
563 | |
564 | kxc_answer(kx, kxc); |
565 | |
566 | /* --- Tidy up and go home --- */ |
567 | |
568 | tidy: |
569 | mp_drop(c); |
5d418e24 |
570 | mp_drop(ck); |
0617b6e7 |
571 | return (0); |
572 | |
573 | bad: |
574 | mp_drop(c); |
5d418e24 |
575 | mp_drop(ck); |
0617b6e7 |
576 | return (-1); |
410c8acf |
577 | } |
578 | |
0617b6e7 |
579 | /* --- @resend@ --- * |
410c8acf |
580 | * |
581 | * Arguments: @keyexch *kx@ = pointer to key exchange context |
410c8acf |
582 | * |
583 | * Returns: --- |
584 | * |
0617b6e7 |
585 | * Use: Sends the next message for a key exchange. |
410c8acf |
586 | */ |
587 | |
0617b6e7 |
588 | static void resend(keyexch *kx) |
410c8acf |
589 | { |
0617b6e7 |
590 | kxchal *kxc; |
591 | buf bb; |
592 | stats *st = p_stats(kx->p); |
410c8acf |
593 | buf *b; |
594 | |
0617b6e7 |
595 | switch (kx->s) { |
596 | case KXS_CHAL: |
00e64b67 |
597 | T( trace(T_KEYEXCH, "keyexch: sending prechallenge to `%s'", |
598 | p_name(kx->p)); ) |
0617b6e7 |
599 | b = p_txstart(kx->p, MSG_KEYEXCH | KX_PRECHAL); |
600 | buf_putmp(b, kx->c); |
601 | break; |
602 | case KXS_COMMIT: |
00e64b67 |
603 | T( trace(T_KEYEXCH, "keyexch: sending switch request to `%s'", |
604 | p_name(kx->p)); ) |
0617b6e7 |
605 | kxc = kx->r[0]; |
606 | b = p_txstart(kx->p, MSG_KEYEXCH | KX_SWITCH); |
607 | buf_put(b, kx->hc, HASHSZ); |
608 | buf_put(b, kxc->hc, HASHSZ); |
609 | buf_init(&bb, buf_i, sizeof(buf_i)); |
610 | buf_putmp(&bb, kxc->r); |
611 | buf_put(&bb, kxc->hswrq_out, HASHSZ); |
612 | buf_flip(&bb); |
613 | ks_encrypt(kxc->ks, &bb, b); |
614 | break; |
615 | case KXS_SWITCH: |
00e64b67 |
616 | T( trace(T_KEYEXCH, "keyexch: sending switch confirmation to `%s'", |
0617b6e7 |
617 | p_name(kx->p)); ) |
618 | kxc = kx->r[0]; |
619 | b = p_txstart(kx->p, MSG_KEYEXCH | KX_SWITCHOK); |
620 | buf_init(&bb, buf_i, sizeof(buf_i)); |
621 | buf_put(&bb, kxc->hswok_out, HASHSZ); |
622 | buf_flip(&bb); |
623 | ks_encrypt(kxc->ks, &bb, b); |
624 | break; |
625 | default: |
626 | abort(); |
410c8acf |
627 | } |
0617b6e7 |
628 | |
629 | if (BOK(b)) { |
630 | st->n_kxout++; |
631 | st->sz_kxout += BLEN(b); |
632 | p_txend(kx->p); |
633 | } |
634 | |
635 | if (kx->s < KXS_SWITCH) |
636 | settimer(kx, time(0) + T_RETRY); |
410c8acf |
637 | } |
638 | |
0617b6e7 |
639 | /* --- @matchreply@ --- * |
640 | * |
641 | * Arguments: @keyexch *kx@ = pointer to key exchange context |
642 | * @const octet *hc_in@ = a hash of his challenge |
643 | * @const octet *hc_out@ = a hash of my challenge (cookie) |
5d418e24 |
644 | * @mp *ck@ = his expected-reply hash (optional) |
0617b6e7 |
645 | * @buf *b@ = encrypted remainder of the packet |
646 | * |
647 | * Returns: A pointer to the challenge block if OK, or null on failure. |
648 | * |
649 | * Use: Checks a reply or switch packet, ensuring that its contents |
650 | * are sensible and correct. If they are, @*b@ is set to point |
651 | * to the remainder of the encrypted data, and the correct |
652 | * challenge is returned. |
653 | */ |
654 | |
655 | static kxchal *matchreply(keyexch *kx, const octet *hc_in, |
5d418e24 |
656 | const octet *hc_out, mp *ck, buf *b) |
410c8acf |
657 | { |
0617b6e7 |
658 | kxchal *kxc; |
659 | buf bb; |
660 | mp *r = 0; |
661 | |
662 | /* --- Check the plaintext portions of the data --- */ |
663 | |
664 | IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, { |
665 | trace_block(T_CRYPTO, "crypto: challenge", hc_in, HASHSZ); |
666 | trace_block(T_CRYPTO, "crypto: cookie", hc_out, HASHSZ); |
5d418e24 |
667 | if (ck) trace(T_CRYPTO, "crypto: check value = %s", mpstr(ck)); |
0617b6e7 |
668 | })) |
669 | if (memcmp(hc_out, kx->hc, HASHSZ) != 0) { |
670 | a_warn("incorrect cookie from `%s'", p_name(kx->p)); |
671 | goto bad; |
672 | } |
673 | if ((kxc = kxc_byhc(kx, hc_in)) == 0) { |
674 | a_warn("received reply for unknown challenge from `%s'", p_name(kx->p)); |
675 | goto bad; |
676 | } |
410c8acf |
677 | |
0617b6e7 |
678 | /* --- Maybe compute a reply for the challenge --- */ |
679 | |
680 | if (!kxc->r) { |
5d418e24 |
681 | if (!ck) { |
0617b6e7 |
682 | a_warn("unexpected switch request from `%s'", p_name(kx->p)); |
683 | goto bad; |
684 | } |
5d418e24 |
685 | if ((r = getreply(kx, kxc->c, ck)) == 0) |
0617b6e7 |
686 | goto bad; |
687 | kxc->r = r; |
688 | r = 0; |
689 | } |
690 | |
691 | /* --- Decrypt the rest of the packet --- */ |
692 | |
693 | buf_init(&bb, buf_o, sizeof(buf_o)); |
694 | if (ks_decrypt(kxc->ks, b, &bb)) { |
695 | a_warn("failed to decrypt reply from `%s'", p_name(kx->p)); |
696 | goto bad; |
410c8acf |
697 | } |
0617b6e7 |
698 | buf_init(b, BBASE(&bb), BLEN(&bb)); |
699 | if ((r = buf_getmp(b)) == 0) { |
700 | a_warn("invalid reply packet from `%s'", p_name(kx->p)); |
701 | goto bad; |
702 | } |
703 | IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, { |
704 | trace(T_CRYPTO, "crypto: reply = %s", mpstr(r)); |
705 | })) |
706 | if (!mp_eq(r, kx->rx)) { |
707 | a_warn("incorrect reply from `%s'", p_name(kx->p)); |
708 | goto bad; |
709 | } |
710 | |
711 | /* --- Done --- */ |
712 | |
713 | mp_drop(r); |
714 | return (kxc); |
715 | |
716 | bad: |
717 | mp_drop(r); |
718 | return (0); |
410c8acf |
719 | } |
720 | |
0617b6e7 |
721 | /* --- @commit@ --- * |
410c8acf |
722 | * |
723 | * Arguments: @keyexch *kx@ = pointer to key exchange context |
0617b6e7 |
724 | * @kxchal *kxc@ = pointer to challenge to commit to |
410c8acf |
725 | * |
726 | * Returns: --- |
727 | * |
0617b6e7 |
728 | * Use: Commits to a particular challenge as being the `right' one, |
729 | * since a reply has arrived for it. |
410c8acf |
730 | */ |
731 | |
0617b6e7 |
732 | static void commit(keyexch *kx, kxchal *kxc) |
410c8acf |
733 | { |
0617b6e7 |
734 | unsigned i; |
410c8acf |
735 | |
0617b6e7 |
736 | for (i = 0; i < kx->nr; i++) { |
737 | if (kx->r[i] != kxc) |
738 | kxc_destroy(kx->r[i]); |
739 | } |
740 | kx->r[0] = kxc; |
741 | kx->nr = 1; |
742 | kxc_stoptimer(kxc); |
743 | ksl_link(kx->ks, kxc->ks); |
410c8acf |
744 | } |
745 | |
0617b6e7 |
746 | /* --- @doreply@ --- * |
410c8acf |
747 | * |
748 | * Arguments: @keyexch *kx@ = pointer to key exchange context |
0617b6e7 |
749 | * @buf *b@ = buffer containing packet |
410c8acf |
750 | * |
0617b6e7 |
751 | * Returns: Zero if OK, nonzero if the packet was rejected. |
410c8acf |
752 | * |
0617b6e7 |
753 | * Use: Handles a reply packet. This doesn't handle the various |
754 | * switch packets: they're rather too different. |
410c8acf |
755 | */ |
756 | |
0617b6e7 |
757 | static int doreply(keyexch *kx, buf *b) |
410c8acf |
758 | { |
5d418e24 |
759 | const octet *hc_in, *hc_out; |
760 | mp *ck = 0; |
0617b6e7 |
761 | kxchal *kxc; |
762 | |
763 | if (kx->s != KXS_CHAL && kx->s != KXS_COMMIT) { |
764 | a_warn("unexpected reply from `%s'", p_name(kx->p)); |
765 | goto bad; |
766 | } |
767 | if ((hc_in = buf_get(b, HASHSZ)) == 0 || |
768 | (hc_out = buf_get(b, HASHSZ)) == 0 || |
5d418e24 |
769 | (ck = buf_getmp(b)) == 0) { |
0617b6e7 |
770 | a_warn("invalid reply packet from `%s'", p_name(kx->p)); |
771 | goto bad; |
772 | } |
5d418e24 |
773 | if ((kxc = matchreply(kx, hc_in, hc_out, ck, b)) == 0) |
0617b6e7 |
774 | goto bad; |
775 | if (BLEFT(b)) { |
776 | a_warn("invalid reply packet from `%s'", p_name(kx->p)); |
777 | goto bad; |
778 | } |
779 | if (kx->s == KXS_CHAL) { |
780 | commit(kx, kxc); |
781 | kx->s = KXS_COMMIT; |
782 | } |
783 | resend(kx); |
784 | return (0); |
785 | |
786 | bad: |
5d418e24 |
787 | mp_drop(ck); |
0617b6e7 |
788 | return (-1); |
410c8acf |
789 | } |
790 | |
0617b6e7 |
791 | /* --- @doswitch@ --- * |
410c8acf |
792 | * |
0617b6e7 |
793 | * Arguments: @keyexch *kx@ = pointer to key exchange block |
794 | * @buf *b@ = pointer to buffer containing packet |
410c8acf |
795 | * |
0617b6e7 |
796 | * Returns: Zero if OK, nonzero if the packet was rejected. |
410c8acf |
797 | * |
0617b6e7 |
798 | * Use: Handles a reply with a switch request bolted onto it. |
410c8acf |
799 | */ |
800 | |
0617b6e7 |
801 | static int doswitch(keyexch *kx, buf *b) |
410c8acf |
802 | { |
0617b6e7 |
803 | const octet *hc_in, *hc_out, *hswrq; |
804 | kxchal *kxc; |
410c8acf |
805 | |
0617b6e7 |
806 | if ((hc_in = buf_get(b, HASHSZ)) == 0 || |
807 | (hc_out = buf_get(b, HASHSZ)) == 0) { |
808 | a_warn("invalid switch request from `%s'", p_name(kx->p)); |
809 | goto bad; |
410c8acf |
810 | } |
0617b6e7 |
811 | if ((kxc = matchreply(kx, hc_in, hc_out, 0, b)) == 0) |
812 | goto bad; |
813 | if ((hswrq = buf_get(b, HASHSZ)) == 0 || BLEFT(b)) { |
814 | a_warn("invalid switch request from `%s'", p_name(kx->p)); |
815 | goto bad; |
816 | } |
817 | IF_TRACING(T_KEYEXCH, { |
818 | trace_block(T_CRYPTO, "crypto: switch request hash", hswrq, HASHSZ); |
819 | }) |
820 | if (memcmp(hswrq, kxc->hswrq_in, HASHSZ) != 0) { |
821 | a_warn("incorrect switch request hash from `%s'", p_name(kx->p)); |
822 | goto bad; |
823 | } |
824 | switch (kx->s) { |
825 | case KXS_CHAL: |
826 | commit(kx, kxc); |
827 | case KXS_COMMIT: |
828 | ks_activate(kxc->ks); |
829 | settimer(kx, ks_tregen(kxc->ks)); |
830 | kx->s = KXS_SWITCH; |
831 | break; |
832 | } |
833 | resend(kx); |
834 | return (0); |
835 | |
836 | bad: |
837 | return (-1); |
410c8acf |
838 | } |
839 | |
0617b6e7 |
840 | /* --- @doswitchok@ --- * |
841 | * |
842 | * Arguments: @keyexch *kx@ = pointer to key exchange block |
843 | * @buf *b@ = pointer to buffer containing packet |
844 | * |
845 | * Returns: Zero if OK, nonzero if the packet was rejected. |
846 | * |
847 | * Use: Handles a reply with a switch request bolted onto it. |
848 | */ |
849 | |
850 | static int doswitchok(keyexch *kx, buf *b) |
410c8acf |
851 | { |
0617b6e7 |
852 | const octet *hswok; |
853 | kxchal *kxc; |
854 | buf bb; |
410c8acf |
855 | |
0617b6e7 |
856 | if (kx->s < KXS_COMMIT) { |
857 | a_warn("unexpected switch confirmation from `%s'", p_name(kx->p)); |
858 | goto bad; |
410c8acf |
859 | } |
0617b6e7 |
860 | kxc = kx->r[0]; |
861 | buf_init(&bb, buf_o, sizeof(buf_o)); |
862 | if (ks_decrypt(kxc->ks, b, &bb)) { |
863 | a_warn("failed to decrypt switch confirmation from `%s'", p_name(kx->p)); |
864 | goto bad; |
865 | } |
866 | buf_init(b, BBASE(&bb), BLEN(&bb)); |
867 | if ((hswok = buf_get(b, HASHSZ)) == 0 || BLEFT(b)) { |
868 | a_warn("invalid switch confirmation from `%s'", p_name(kx->p)); |
869 | goto bad; |
870 | } |
871 | IF_TRACING(T_KEYEXCH, { |
872 | trace_block(T_CRYPTO, "crypto: switch confirmation hash", hswok, HASHSZ); |
873 | }) |
874 | if (memcmp(hswok, kxc->hswok_in, HASHSZ) != 0) { |
875 | a_warn("incorrect switch confirmation hash from `%s'", p_name(kx->p)); |
876 | goto bad; |
877 | } |
878 | if (kx->s < KXS_SWITCH) { |
879 | ks_activate(kxc->ks); |
880 | settimer(kx, ks_tregen(kxc->ks)); |
881 | kx->s = KXS_SWITCH; |
882 | } |
883 | return (0); |
884 | |
885 | bad: |
886 | return (-1); |
887 | } |
888 | |
889 | /*----- Main code ---------------------------------------------------------*/ |
890 | |
891 | /* --- @stop@ --- * |
892 | * |
893 | * Arguments: @keyexch *kx@ = pointer to key exchange context |
894 | * |
895 | * Returns: --- |
896 | * |
897 | * Use: Stops a key exchange dead in its tracks. Throws away all of |
898 | * the context information. The context is left in an |
899 | * inconsistent state. The only functions which understand this |
900 | * state are @kx_free@ and @kx_init@ (which cause it internally |
901 | * it), and @start@ (which expects it to be the prevailing |
902 | * state). |
903 | */ |
904 | |
905 | static void stop(keyexch *kx) |
906 | { |
907 | unsigned i; |
908 | |
00e64b67 |
909 | if (kx->f & KXF_DEAD) |
910 | return; |
911 | |
0617b6e7 |
912 | if (kx->f & KXF_TIMER) |
913 | sel_rmtimer(&kx->t); |
914 | for (i = 0; i < kx->nr; i++) |
915 | kxc_destroy(kx->r[i]); |
916 | mp_drop(kx->alpha); |
917 | mp_drop(kx->c); |
918 | mp_drop(kx->rx); |
00e64b67 |
919 | kx->t_valid = 0; |
920 | kx->f |= KXF_DEAD; |
921 | kx->f &= ~KXF_TIMER; |
0617b6e7 |
922 | } |
923 | |
924 | /* --- @start@ --- * |
925 | * |
926 | * Arguments: @keyexch *kx@ = pointer to key exchange context |
927 | * @time_t now@ = the current time |
928 | * |
929 | * Returns: --- |
930 | * |
931 | * Use: Starts a new key exchange with the peer. The context must be |
932 | * in the bizarre state left by @stop@ or @kx_init@. |
933 | */ |
934 | |
935 | static void start(keyexch *kx, time_t now) |
936 | { |
937 | HASH_CTX h; |
938 | |
00e64b67 |
939 | assert(kx->f & KXF_DEAD); |
940 | |
941 | kx->f &= ~KXF_DEAD; |
0617b6e7 |
942 | kx->nr = 0; |
0617b6e7 |
943 | kx->alpha = mprand_range(MP_NEW, kpriv.dp.q, &rand_global, 0); |
944 | kx->c = mpmont_exp(&mg, MP_NEW, kpriv.dp.g, kx->alpha); |
945 | kx->rx = mpmont_exp(&mg, MP_NEW, kx->kpub.y, kx->alpha); |
946 | kx->s = KXS_CHAL; |
947 | kx->t_valid = now + T_VALID; |
948 | |
949 | HASH_INIT(&h); |
950 | HASH_STRING(&h, "tripe-cookie"); |
951 | hashmp(&h, kx->c); |
952 | HASH_DONE(&h, kx->hc); |
953 | |
954 | IF_TRACING(T_KEYEXCH, { |
955 | trace(T_KEYEXCH, "keyexch: creating new challenge"); |
956 | IF_TRACING(T_CRYPTO, { |
957 | trace(T_CRYPTO, "crypto: secret = %s", mpstr(kx->alpha)); |
958 | trace(T_CRYPTO, "crypto: challenge = %s", mpstr(kx->c)); |
959 | trace(T_CRYPTO, "crypto: expected response = %s", mpstr(kx->rx)); |
960 | trace_block(T_CRYPTO, "crypto: challenge cookie", kx->hc, HASHSZ); |
961 | }) |
962 | }) |
410c8acf |
963 | } |
964 | |
00e64b67 |
965 | /* --- @checkpub@ --- * |
966 | * |
967 | * Arguments: @keyexch *kx@ = pointer to key exchange context |
968 | * |
969 | * Returns: Zero if OK, nonzero if the peer's public key has expired. |
970 | * |
971 | * Use: Deactivates the key-exchange until the peer acquires a new |
972 | * public key. |
973 | */ |
974 | |
975 | static int checkpub(keyexch *kx) |
976 | { |
977 | time_t now; |
978 | if (kx->f & KXF_DEAD) |
979 | return (-1); |
980 | now = time(0); |
981 | if (KEY_EXPIRED(now, kx->texp_kpub)) { |
982 | stop(kx); |
983 | a_warn("public key for `%s' has expired", p_name(kx->p)); |
984 | dh_pubfree(&kx->kpub); |
985 | kx->f &= ~KXF_PUBKEY; |
986 | return (-1); |
987 | } |
988 | return (0); |
989 | } |
990 | |
0617b6e7 |
991 | /* --- @kx_start@ --- * |
410c8acf |
992 | * |
993 | * Arguments: @keyexch *kx@ = pointer to key exchange context |
410c8acf |
994 | * |
995 | * Returns: --- |
996 | * |
0617b6e7 |
997 | * Use: Stimulates a key exchange. If a key exchage is in progress, |
998 | * a new challenge is sent (unless the quiet timer forbids |
999 | * this); if no exchange is in progress, one is commenced. |
410c8acf |
1000 | */ |
1001 | |
0617b6e7 |
1002 | void kx_start(keyexch *kx) |
410c8acf |
1003 | { |
1004 | time_t now = time(0); |
410c8acf |
1005 | |
00e64b67 |
1006 | if (checkpub(kx)) |
1007 | return; |
0617b6e7 |
1008 | if (!ISVALID(kx, now)) { |
1009 | stop(kx); |
1010 | start(kx, now); |
410c8acf |
1011 | } |
0617b6e7 |
1012 | resend(kx); |
1013 | } |
1014 | |
1015 | /* --- @kx_message@ --- * |
1016 | * |
1017 | * Arguments: @keyexch *kx@ = pointer to key exchange context |
1018 | * @unsigned msg@ = the message code |
1019 | * @buf *b@ = pointer to buffer containing the packet |
1020 | * |
1021 | * Returns: --- |
1022 | * |
1023 | * Use: Reads a packet containing key exchange messages and handles |
1024 | * it. |
1025 | */ |
1026 | |
1027 | void kx_message(keyexch *kx, unsigned msg, buf *b) |
1028 | { |
1029 | time_t now = time(0); |
1030 | stats *st = p_stats(kx->p); |
1031 | size_t sz = BSZ(b); |
1032 | int rc; |
1033 | |
1034 | #ifndef NTRACE |
1035 | static const char *const pkname[] = { |
1036 | "prechallenge", "cookie", "challenge", |
1037 | "reply", "switch request", "switch confirmation" |
1038 | }; |
1039 | #endif |
1040 | |
00e64b67 |
1041 | if (checkpub(kx)) |
1042 | return; |
1043 | |
0617b6e7 |
1044 | if (!ISVALID(kx, now)) { |
1045 | stop(kx); |
1046 | start(kx, now); |
410c8acf |
1047 | } |
0617b6e7 |
1048 | |
1049 | T( trace(T_KEYEXCH, "keyexch: processing %s packet from `%s'", |
1050 | msg < KX_NMSG ? pkname[msg] : "unknown", p_name(kx->p)); ) |
1051 | |
1052 | switch (msg) { |
1053 | case KX_PRECHAL: |
1054 | case KX_COOKIE: |
1055 | case KX_CHAL: |
1056 | rc = dochallenge(kx, msg, b); |
1057 | break; |
1058 | case KX_REPLY: |
1059 | rc = doreply(kx, b); |
1060 | break; |
1061 | case KX_SWITCH: |
1062 | rc = doswitch(kx, b); |
1063 | break; |
1064 | case KX_SWITCHOK: |
1065 | rc = doswitchok(kx, b); |
1066 | break; |
1067 | default: |
1068 | a_warn("unexpected key exchange message type %u from `%p'", |
1069 | p_name(kx->p)); |
1070 | rc = -1; |
1071 | break; |
410c8acf |
1072 | } |
410c8acf |
1073 | |
0617b6e7 |
1074 | if (rc) |
1075 | st->n_reject++; |
1076 | else { |
1077 | st->n_kxin++; |
1078 | st->sz_kxin += sz; |
1079 | } |
410c8acf |
1080 | } |
1081 | |
1082 | /* --- @kx_free@ --- * |
1083 | * |
1084 | * Arguments: @keyexch *kx@ = pointer to key exchange context |
1085 | * |
1086 | * Returns: --- |
1087 | * |
1088 | * Use: Frees everything in a key exchange context. |
1089 | */ |
1090 | |
1091 | void kx_free(keyexch *kx) |
1092 | { |
0617b6e7 |
1093 | stop(kx); |
00e64b67 |
1094 | if (kx->f & KXF_PUBKEY) |
1095 | dh_pubfree(&kx->kpub); |
410c8acf |
1096 | } |
1097 | |
1098 | /* --- @kx_newkeys@ --- * |
1099 | * |
1100 | * Arguments: @keyexch *kx@ = pointer to key exchange context |
1101 | * |
1102 | * Returns: --- |
1103 | * |
1104 | * Use: Informs the key exchange module that its keys may have |
1105 | * changed. If fetching the new keys fails, the peer will be |
1106 | * destroyed, we log messages and struggle along with the old |
1107 | * keys. |
1108 | */ |
1109 | |
1110 | void kx_newkeys(keyexch *kx) |
1111 | { |
1112 | dh_pub dp; |
1113 | |
00e64b67 |
1114 | if (km_getpubkey(p_name(kx->p), &dp, &kx->texp_kpub)) |
410c8acf |
1115 | return; |
00e64b67 |
1116 | if (kx->f & KXF_PUBKEY) |
1117 | dh_pubfree(&kx->kpub); |
410c8acf |
1118 | kx->kpub = dp; |
00e64b67 |
1119 | kx->f |= KXF_PUBKEY; |
1120 | if ((kx->f & KXF_DEAD) || kx->s != KXS_SWITCH) { |
410c8acf |
1121 | T( trace(T_KEYEXCH, "keyexch: restarting key negotiation with `%s'", |
1122 | p_name(kx->p)); ) |
00e64b67 |
1123 | stop(kx); |
1124 | start(kx, time(0)); |
1125 | resend(kx); |
410c8acf |
1126 | } |
1127 | } |
1128 | |
1129 | /* --- @kx_init@ --- * |
1130 | * |
1131 | * Arguments: @keyexch *kx@ = pointer to key exchange context |
1132 | * @peer *p@ = pointer to peer context |
1133 | * @keyset **ks@ = pointer to keyset list |
1134 | * |
1135 | * Returns: Zero if OK, nonzero if it failed. |
1136 | * |
1137 | * Use: Initializes a key exchange module. The module currently |
1138 | * contains no keys, and will attempt to initiate a key |
1139 | * exchange. |
1140 | */ |
1141 | |
1142 | int kx_init(keyexch *kx, peer *p, keyset **ks) |
1143 | { |
1144 | kx->ks = ks; |
1145 | kx->p = p; |
00e64b67 |
1146 | if (km_getpubkey(p_name(p), &kx->kpub, &kx->texp_kpub)) |
410c8acf |
1147 | return (-1); |
00e64b67 |
1148 | kx->f = KXF_DEAD | KXF_PUBKEY; |
0617b6e7 |
1149 | start(kx, time(0)); |
1150 | resend(kx); |
410c8acf |
1151 | return (0); |
1152 | } |
1153 | |
1154 | /*----- That's all, folks -------------------------------------------------*/ |