3 * $Id: keyexch.c,v 1.2 2001/02/16 21:24:27 mdw Exp $
5 * Key exchange protocol
7 * (c) 2001 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Trivial IP Encryption (TrIPE).
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.
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.
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.
29 /*----- Revision history --------------------------------------------------*
32 * Revision 1.2 2001/02/16 21:24:27 mdw
33 * Rewrite for new key exchange protocol.
35 * Revision 1.1 2001/02/03 20:26:37 mdw
40 /*----- Header files ------------------------------------------------------*/
44 /*----- Tunable parameters ------------------------------------------------*/
46 #define T_VALID MIN(2)
47 #define T_RETRY SEC(10)
49 #define ISVALID(kx, now) ((now) < (kx)->t_valid)
51 /*----- Various utilities -------------------------------------------------*/
55 * Arguments: @HASH_CTX *r@ = pointer to hash context
56 * @mp *m@ = pointer to multiprecision integer
60 * Use: Adds the hash of a multiprecision integer to the context.
64 static void hashmp(HASH_CTX *r, mp *m)
67 buf_init(&b, buf_t, sizeof(buf_t));
70 HASH(r, BBASE(&b), BLEN(&b));
75 * Arguments: @struct timeval *tv@ = the current time
76 * @void *v@ = pointer to key exchange context
80 * Use: Acts when the key exchange timer goes off.
83 static void timer(struct timeval *tv, void *v)
87 T( trace(T_KEYEXCH, "keyexch: timer has popped"); )
91 /* --- @settimer@ --- *
93 * Arguments: @keyexch *kx@ = pointer to key exchange context
94 * @time_t t@ = when to set the timer for
98 * Use: Sets the timer for the next key exchange attempt.
101 static void settimer(keyexch *kx, time_t t)
104 if (kx->f & KXF_TIMER)
108 sel_addtimer(&sel, &kx->t, &tv, timer, kx);
112 /*----- Challenge management ----------------------------------------------*/
114 /* --- Notes on challenge management --- *
116 * We may get multiple different replies to our key exchange; some will be
117 * correct, some inserted by attackers. Up until @KX_THRESH@, all challenges
118 * received will be added to the table and given a full response. After
119 * @KX_THRESH@ distinct challenges are received, we return only a `cookie':
120 * our existing challenge, followed by a hash of the sender's challenge. We
121 * do %%\emph{not}%% give a bare challenge a reply slot at this stage. All
122 * properly-formed cookies are assigned a table slot: if none is spare, a
123 * used slot is randomly selected and destroyed. A cookie always receives a
127 /* --- @kxc_destroy@ --- *
129 * Arguments: @kxchal *kxc@ = pointer to the challenge block
133 * Use: Disposes of a challenge block.
136 static void kxc_destroy(kxchal *kxc)
138 if (kxc->f & KXF_TIMER)
139 sel_rmtimer(&kxc->t);
146 /* --- @kxc_stoptimer@ --- *
148 * Arguments: @kxchal *kxc@ = pointer to the challenge block
152 * Use: Stops the challenge's retry timer from sending messages.
153 * Useful when the state machine is in the endgame of the
157 static void kxc_stoptimer(kxchal *kxc)
159 if (kxc->f & KXF_TIMER)
160 sel_rmtimer(&kxc->t);
163 /* --- @kxc_new@ --- *
165 * Arguments: @keyexch *kx@ = pointer to key exchange block
168 * Returns: A pointer to the challenge block.
170 * Use: Returns a pointer to a new challenge block to fill in.
173 static kxchal *kxc_new(keyexch *kx)
178 /* --- If we're over reply threshold, discard one at random --- */
180 if (kx->nr < KX_NCHAL)
183 i = rand_global.ops->range(&rand_global, KX_NCHAL);
184 kxc_destroy(kx->r[i]);
187 /* --- Fill in the new structure --- */
189 kxc = CREATE(kxchal);
199 /* --- @kxc_bychal@ --- *
201 * Arguments: @keyexch *kx@ = pointer to key exchange block
202 * @mp *c@ = challenge from remote host
204 * Returns: Pointer to the challenge block, or null.
206 * Use: Finds a challenge block, given its challenge.
209 static kxchal *kxc_bychal(keyexch *kx, mp *c)
213 for (i = 0; i < kx->nr; i++) {
214 if (MP_EQ(c, kx->r[i]->c))
220 /* --- @kxc_byhc@ --- *
222 * Arguments: @keyexch *kx@ = pointer to key exchange block
223 * @const octet *hc@ = challenge hash from remote host
225 * Returns: Pointer to the challenge block, or null.
227 * Use: Finds a challenge block, given a hash of its challenge.
230 static kxchal *kxc_byhc(keyexch *kx, const octet *hc)
234 for (i = 0; i < kx->nr; i++) {
235 if (memcmp(hc, kx->r[i]->hc, HASHSZ) == 0)
241 /* --- @kxc_answer@ --- *
243 * Arguments: @keyexch *kx@ = pointer to key exchange block
244 * @kxchal *kxc@ = pointer to challenge block
248 * Use: Sends a reply to the remote host, according to the data in
249 * this challenge block.
252 static void kxc_answer(keyexch *kx, kxchal *kxc);
254 static void kxc_timer(struct timeval *tv, void *v)
257 kxc->f &= ~KXF_TIMER;
258 kxc_answer(kxc->kx, kxc);
261 static void kxc_answer(keyexch *kx, kxchal *kxc)
263 stats *st = p_stats(kx->p);
264 buf *b = p_txstart(kx->p, MSG_KEYEXCH | (kxc->r ? KX_REPLY : KX_CHAL));
268 /* --- Build the reply packet --- */
273 buf_put(b, kx->hc, HASHSZ);
274 buf_put(b, kxc->hc, HASHSZ);
275 buf_put(b, kxc->hrx, HASHSZ);
277 /* --- Maybe send an actual reply, if we have one --- */
280 T( trace(T_KEYEXCH, "keyexch: resending challenge to `%s'",
283 T( trace(T_KEYEXCH, "keyexch: sending reply to `%s'", p_name(kx->p)); )
284 buf_init(&bb, buf_i, sizeof(buf_i));
285 buf_putmp(&bb, kxc->r);
287 ks_encrypt(kxc->ks, &bb, b);
290 /* --- Update the statistics --- */
294 st->sz_kxout += BLEN(b);
298 /* --- Schedule another resend --- */
300 if (kxc->f & KXF_TIMER)
301 sel_rmtimer(&kxc->t);
302 gettimeofday(&tv, 0);
303 tv.tv_sec += T_RETRY;
304 sel_addtimer(&sel, &kxc->t, &tv, kxc_timer, kxc);
308 /*----- Individual message handlers ---------------------------------------*/
310 /* --- @getreply@ --- *
312 * Arguments: @keyexch *kx@ = pointer to key exchange context
313 * @mp *c@ = a challenge
314 * @const octet *hrx@ = the supplied expected-reply hash
316 * Returns: A pointer to the reply, or null if the reply-hash was wrong.
318 * Use: Computes replies to challenges.
321 static mp *getreply(keyexch *kx, mp *c, const octet *hrx)
323 mp *r = mpmont_exp(&mg, MP_NEW, c, kpriv.x);
328 HASH_STRING(&h, "tripe-expected-reply");
333 IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
334 trace(T_CRYPTO, "crypto: computed reply = %s", mpstr(r));
335 trace_block(T_CRYPTO, "crypto: computed reply hash", buf, HASHSZ);
337 if (memcmp(buf, hrx, HASHSZ) != 0) {
338 a_warn("invalid expected-reply hash from `%s'", p_name(kx->p));
345 /* --- @dochallenge@ --- *
347 * Arguments: @keyexch *kx@ = pointer to key exchange block
348 * @unsigned msg@ = message code for the packet
349 * @buf *b@ = buffer containing the packet
351 * Returns: Zero if OK, nonzero if the packet was rejected.
353 * Use: Processes a packet containing a challenge.
356 static int dochallenge(keyexch *kx, unsigned msg, buf *b)
359 const octet *hc = 0, *hrx = 0;
363 /* --- Ensure that we're in a sensible state --- */
365 if (kx->s != KXS_CHAL) {
366 a_warn("unexpected challenge from `%s'", p_name(kx->p));
370 /* --- Unpack the packet --- */
372 if ((c = buf_getmp(b)) == 0 ||
373 (msg >= KX_COOKIE && (hc = buf_get(b, HASHSZ)) == 0) ||
374 (msg >= KX_CHAL && (hrx = buf_get(b, HASHSZ)) == 0) ||
376 a_warn("malformed packet from `%s'", p_name(kx->p));
380 IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
381 trace(T_CRYPTO, "crypto: challenge = %s", mpstr(c));
382 if (hc) trace_block(T_CRYPTO, "crypto: cookie", hc, HASHSZ);
383 if (hrx) trace_block(T_CRYPTO, "crypto: response hash", hrx, HASHSZ);
386 /* --- First, handle a bare challenge --- *
388 * If the table is heavily loaded, just emit a cookie and return.
391 if (!hc && kx->nr >= KX_THRESH) {
392 T( trace(T_KEYEXCH, "keyexch: too many challenges -- sending cookie"); )
393 b = p_txstart(kx->p, MSG_KEYEXCH | KX_COOKIE);
396 HASH_STRING(&h, "tripe-cookie");
398 HASH_DONE(&h, buf_get(b, HASHSZ));
403 /* --- Discard a packet with an invalid cookie --- */
405 if (hc && memcmp(hc, kx->hc, HASHSZ) != 0) {
406 a_warn("incorrect cookie from `%s'", p_name(kx->p));
410 /* --- Find a challenge block for this packet --- *
412 * If there isn't one already, create a new one.
415 if ((kxc = kxc_bychal(kx, c)) == 0) {
419 /* --- Be careful here --- *
421 * If this is a full challenge, and it's the first time I've seen it, I
422 * want to be able to throw it away before committing a table entry to
429 if ((r = getreply(kx, c, hrx)) == 0)
436 /* --- Work out the cookie for this challenge --- */
439 HASH_STRING(&h, "tripe-cookie");
441 HASH_DONE(&h, kxc->hc);
443 /* --- Compute the expected-reply hash --- */
446 HASH_STRING(&h, "tripe-expected-reply");
450 HASH_DONE(&h, kxc->hrx);
452 /* --- Work out the shared key --- */
454 r = mpmont_exp(&mg, MP_NEW, c, kx->alpha);
456 /* --- Compute the switch messages --- */
458 HASH_INIT(&h); HASH_STRING(&h, "tripe-switch-request");
459 hashmp(&h, kx->c); hashmp(&h, kxc->c);
460 HASH_DONE(&h, kxc->hswrq_out);
461 HASH_INIT(&h); HASH_STRING(&h, "tripe-switch-confirm");
462 hashmp(&h, kx->c); hashmp(&h, kxc->c);
463 HASH_DONE(&h, kxc->hswok_out);
465 HASH_INIT(&h); HASH_STRING(&h, "tripe-switch-request");
466 hashmp(&h, kxc->c); hashmp(&h, kx->c);
467 HASH_DONE(&h, kxc->hswrq_in);
468 HASH_INIT(&h); HASH_STRING(&h, "tripe-switch-confirm");
469 hashmp(&h, kxc->c); hashmp(&h, kx->c);
470 HASH_DONE(&h, kxc->hswok_in);
472 IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
473 trace_block(T_CRYPTO, "crypto: computed cookie", kxc->hc, HASHSZ);
474 trace_block(T_CRYPTO, "crypto: my reply hash", kxc->hrx, HASHSZ);
475 trace(T_CRYPTO, "crypto: shared secret = %s", mpstr(r));
476 trace_block(T_CRYPTO, "crypto: outbound switch request",
477 kxc->hswrq_out, HASHSZ);
478 trace_block(T_CRYPTO, "crypto: outbound switch confirm",
479 kxc->hswok_out, HASHSZ);
480 trace_block(T_CRYPTO, "crypto: inbound switch request",
481 kxc->hswrq_in, HASHSZ);
482 trace_block(T_CRYPTO, "crypto: inbound switch confirm",
483 kxc->hswok_in, HASHSZ);
486 /* --- Create a new symmetric keyset --- */
488 buf_init(b, buf_o, sizeof(buf_o));
489 buf_putmp(b, kx->c); x = BLEN(b);
490 buf_putmp(b, kxc->c); y = BLEN(b);
491 buf_putmp(b, r); z = BLEN(b);
494 kxc->ks = ks_gen(BBASE(b), x, y, z);
498 /* --- Answer the challenge if we need to --- */
500 if (hrx && !kxc->r) {
502 if ((r = getreply(kx, c, hrx)) == 0)
509 /* --- Tidy up and go home --- */
520 /* --- @resend@ --- *
522 * Arguments: @keyexch *kx@ = pointer to key exchange context
526 * Use: Sends the next message for a key exchange.
529 static void resend(keyexch *kx)
533 stats *st = p_stats(kx->p);
538 T( trace(T_KEYEXCH, "sending prechallenge to `%s'", p_name(kx->p)); )
539 b = p_txstart(kx->p, MSG_KEYEXCH | KX_PRECHAL);
543 T( trace(T_KEYEXCH, "sending switch request to `%s'", p_name(kx->p)); )
545 b = p_txstart(kx->p, MSG_KEYEXCH | KX_SWITCH);
546 buf_put(b, kx->hc, HASHSZ);
547 buf_put(b, kxc->hc, HASHSZ);
548 buf_init(&bb, buf_i, sizeof(buf_i));
549 buf_putmp(&bb, kxc->r);
550 buf_put(&bb, kxc->hswrq_out, HASHSZ);
552 ks_encrypt(kxc->ks, &bb, b);
555 T( trace(T_KEYEXCH, "sending switch confirmation to `%s'",
558 b = p_txstart(kx->p, MSG_KEYEXCH | KX_SWITCHOK);
559 buf_init(&bb, buf_i, sizeof(buf_i));
560 buf_put(&bb, kxc->hswok_out, HASHSZ);
562 ks_encrypt(kxc->ks, &bb, b);
570 st->sz_kxout += BLEN(b);
574 if (kx->s < KXS_SWITCH)
575 settimer(kx, time(0) + T_RETRY);
578 /* --- @matchreply@ --- *
580 * Arguments: @keyexch *kx@ = pointer to key exchange context
581 * @const octet *hc_in@ = a hash of his challenge
582 * @const octet *hc_out@ = a hash of my challenge (cookie)
583 * @const octet *krx@ = his expected-reply hash (optional)
584 * @buf *b@ = encrypted remainder of the packet
586 * Returns: A pointer to the challenge block if OK, or null on failure.
588 * Use: Checks a reply or switch packet, ensuring that its contents
589 * are sensible and correct. If they are, @*b@ is set to point
590 * to the remainder of the encrypted data, and the correct
591 * challenge is returned.
594 static kxchal *matchreply(keyexch *kx, const octet *hc_in,
595 const octet *hc_out, const octet *hrx, buf *b)
601 /* --- Check the plaintext portions of the data --- */
603 IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
604 trace_block(T_CRYPTO, "crypto: challenge", hc_in, HASHSZ);
605 trace_block(T_CRYPTO, "crypto: cookie", hc_out, HASHSZ);
606 if (hrx) trace_block(T_CRYPTO, "crypto: response hash", hrx, HASHSZ);
608 if (memcmp(hc_out, kx->hc, HASHSZ) != 0) {
609 a_warn("incorrect cookie from `%s'", p_name(kx->p));
612 if ((kxc = kxc_byhc(kx, hc_in)) == 0) {
613 a_warn("received reply for unknown challenge from `%s'", p_name(kx->p));
617 /* --- Maybe compute a reply for the challenge --- */
621 a_warn("unexpected switch request from `%s'", p_name(kx->p));
624 if ((r = getreply(kx, kxc->c, hrx)) == 0)
630 /* --- Decrypt the rest of the packet --- */
632 buf_init(&bb, buf_o, sizeof(buf_o));
633 if (ks_decrypt(kxc->ks, b, &bb)) {
634 a_warn("failed to decrypt reply from `%s'", p_name(kx->p));
637 buf_init(b, BBASE(&bb), BLEN(&bb));
638 if ((r = buf_getmp(b)) == 0) {
639 a_warn("invalid reply packet from `%s'", p_name(kx->p));
642 IF_TRACING(T_KEYEXCH, IF_TRACING(T_CRYPTO, {
643 trace(T_CRYPTO, "crypto: reply = %s", mpstr(r));
645 if (!mp_eq(r, kx->rx)) {
646 a_warn("incorrect reply from `%s'", p_name(kx->p));
660 /* --- @commit@ --- *
662 * Arguments: @keyexch *kx@ = pointer to key exchange context
663 * @kxchal *kxc@ = pointer to challenge to commit to
667 * Use: Commits to a particular challenge as being the `right' one,
668 * since a reply has arrived for it.
671 static void commit(keyexch *kx, kxchal *kxc)
675 for (i = 0; i < kx->nr; i++) {
677 kxc_destroy(kx->r[i]);
682 ksl_link(kx->ks, kxc->ks);
685 /* --- @doreply@ --- *
687 * Arguments: @keyexch *kx@ = pointer to key exchange context
688 * @buf *b@ = buffer containing packet
690 * Returns: Zero if OK, nonzero if the packet was rejected.
692 * Use: Handles a reply packet. This doesn't handle the various
693 * switch packets: they're rather too different.
696 static int doreply(keyexch *kx, buf *b)
698 const octet *hc_in, *hc_out, *hrx;
701 if (kx->s != KXS_CHAL && kx->s != KXS_COMMIT) {
702 a_warn("unexpected reply from `%s'", p_name(kx->p));
705 if ((hc_in = buf_get(b, HASHSZ)) == 0 ||
706 (hc_out = buf_get(b, HASHSZ)) == 0 ||
707 (hrx = buf_get(b, HASHSZ)) == 0) {
708 a_warn("invalid reply packet from `%s'", p_name(kx->p));
711 if ((kxc = matchreply(kx, hc_in, hc_out, hrx, b)) == 0)
714 a_warn("invalid reply packet from `%s'", p_name(kx->p));
717 if (kx->s == KXS_CHAL) {
728 /* --- @doswitch@ --- *
730 * Arguments: @keyexch *kx@ = pointer to key exchange block
731 * @buf *b@ = pointer to buffer containing packet
733 * Returns: Zero if OK, nonzero if the packet was rejected.
735 * Use: Handles a reply with a switch request bolted onto it.
738 static int doswitch(keyexch *kx, buf *b)
740 const octet *hc_in, *hc_out, *hswrq;
743 if ((hc_in = buf_get(b, HASHSZ)) == 0 ||
744 (hc_out = buf_get(b, HASHSZ)) == 0) {
745 a_warn("invalid switch request from `%s'", p_name(kx->p));
748 if ((kxc = matchreply(kx, hc_in, hc_out, 0, b)) == 0)
750 if ((hswrq = buf_get(b, HASHSZ)) == 0 || BLEFT(b)) {
751 a_warn("invalid switch request from `%s'", p_name(kx->p));
754 IF_TRACING(T_KEYEXCH, {
755 trace_block(T_CRYPTO, "crypto: switch request hash", hswrq, HASHSZ);
757 if (memcmp(hswrq, kxc->hswrq_in, HASHSZ) != 0) {
758 a_warn("incorrect switch request hash from `%s'", p_name(kx->p));
765 ks_activate(kxc->ks);
766 settimer(kx, ks_tregen(kxc->ks));
777 /* --- @doswitchok@ --- *
779 * Arguments: @keyexch *kx@ = pointer to key exchange block
780 * @buf *b@ = pointer to buffer containing packet
782 * Returns: Zero if OK, nonzero if the packet was rejected.
784 * Use: Handles a reply with a switch request bolted onto it.
787 static int doswitchok(keyexch *kx, buf *b)
793 if (kx->s < KXS_COMMIT) {
794 a_warn("unexpected switch confirmation from `%s'", p_name(kx->p));
798 buf_init(&bb, buf_o, sizeof(buf_o));
799 if (ks_decrypt(kxc->ks, b, &bb)) {
800 a_warn("failed to decrypt switch confirmation from `%s'", p_name(kx->p));
803 buf_init(b, BBASE(&bb), BLEN(&bb));
804 if ((hswok = buf_get(b, HASHSZ)) == 0 || BLEFT(b)) {
805 a_warn("invalid switch confirmation from `%s'", p_name(kx->p));
808 IF_TRACING(T_KEYEXCH, {
809 trace_block(T_CRYPTO, "crypto: switch confirmation hash", hswok, HASHSZ);
811 if (memcmp(hswok, kxc->hswok_in, HASHSZ) != 0) {
812 a_warn("incorrect switch confirmation hash from `%s'", p_name(kx->p));
815 if (kx->s < KXS_SWITCH) {
816 ks_activate(kxc->ks);
817 settimer(kx, ks_tregen(kxc->ks));
826 /*----- Main code ---------------------------------------------------------*/
830 * Arguments: @keyexch *kx@ = pointer to key exchange context
834 * Use: Stops a key exchange dead in its tracks. Throws away all of
835 * the context information. The context is left in an
836 * inconsistent state. The only functions which understand this
837 * state are @kx_free@ and @kx_init@ (which cause it internally
838 * it), and @start@ (which expects it to be the prevailing
842 static void stop(keyexch *kx)
846 if (kx->f & KXF_TIMER)
848 for (i = 0; i < kx->nr; i++)
849 kxc_destroy(kx->r[i]);
857 * Arguments: @keyexch *kx@ = pointer to key exchange context
858 * @time_t now@ = the current time
862 * Use: Starts a new key exchange with the peer. The context must be
863 * in the bizarre state left by @stop@ or @kx_init@.
866 static void start(keyexch *kx, time_t now)
872 kx->alpha = mprand_range(MP_NEW, kpriv.dp.q, &rand_global, 0);
873 kx->c = mpmont_exp(&mg, MP_NEW, kpriv.dp.g, kx->alpha);
874 kx->rx = mpmont_exp(&mg, MP_NEW, kx->kpub.y, kx->alpha);
876 kx->t_valid = now + T_VALID;
879 HASH_STRING(&h, "tripe-cookie");
881 HASH_DONE(&h, kx->hc);
883 IF_TRACING(T_KEYEXCH, {
884 trace(T_KEYEXCH, "keyexch: creating new challenge");
885 IF_TRACING(T_CRYPTO, {
886 trace(T_CRYPTO, "crypto: secret = %s", mpstr(kx->alpha));
887 trace(T_CRYPTO, "crypto: challenge = %s", mpstr(kx->c));
888 trace(T_CRYPTO, "crypto: expected response = %s", mpstr(kx->rx));
889 trace_block(T_CRYPTO, "crypto: challenge cookie", kx->hc, HASHSZ);
894 /* --- @kx_start@ --- *
896 * Arguments: @keyexch *kx@ = pointer to key exchange context
900 * Use: Stimulates a key exchange. If a key exchage is in progress,
901 * a new challenge is sent (unless the quiet timer forbids
902 * this); if no exchange is in progress, one is commenced.
905 void kx_start(keyexch *kx)
907 time_t now = time(0);
909 if (!ISVALID(kx, now)) {
916 /* --- @kx_message@ --- *
918 * Arguments: @keyexch *kx@ = pointer to key exchange context
919 * @unsigned msg@ = the message code
920 * @buf *b@ = pointer to buffer containing the packet
924 * Use: Reads a packet containing key exchange messages and handles
928 void kx_message(keyexch *kx, unsigned msg, buf *b)
930 time_t now = time(0);
931 stats *st = p_stats(kx->p);
936 static const char *const pkname[] = {
937 "prechallenge", "cookie", "challenge",
938 "reply", "switch request", "switch confirmation"
942 if (!ISVALID(kx, now)) {
947 T( trace(T_KEYEXCH, "keyexch: processing %s packet from `%s'",
948 msg < KX_NMSG ? pkname[msg] : "unknown", p_name(kx->p)); )
954 rc = dochallenge(kx, msg, b);
960 rc = doswitch(kx, b);
963 rc = doswitchok(kx, b);
966 a_warn("unexpected key exchange message type %u from `%p'",
980 /* --- @kx_free@ --- *
982 * Arguments: @keyexch *kx@ = pointer to key exchange context
986 * Use: Frees everything in a key exchange context.
989 void kx_free(keyexch *kx)
992 dh_pubfree(&kx->kpub);
995 /* --- @kx_newkeys@ --- *
997 * Arguments: @keyexch *kx@ = pointer to key exchange context
1001 * Use: Informs the key exchange module that its keys may have
1002 * changed. If fetching the new keys fails, the peer will be
1003 * destroyed, we log messages and struggle along with the old
1007 void kx_newkeys(keyexch *kx)
1011 if (km_getpubkey(p_name(kx->p), &dp))
1013 dh_pubfree(&kx->kpub);
1015 if (kx->s != KXS_SWITCH) {
1016 T( trace(T_KEYEXCH, "keyexch: restarting key negotiation with `%s'",
1023 /* --- @kx_init@ --- *
1025 * Arguments: @keyexch *kx@ = pointer to key exchange context
1026 * @peer *p@ = pointer to peer context
1027 * @keyset **ks@ = pointer to keyset list
1029 * Returns: Zero if OK, nonzero if it failed.
1031 * Use: Initializes a key exchange module. The module currently
1032 * contains no keys, and will attempt to initiate a key
1036 int kx_init(keyexch *kx, peer *p, keyset **ks)
1040 if (km_getpubkey(p_name(p), &kx->kpub))
1047 /*----- That's all, folks -------------------------------------------------*/