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