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Comparing gvpe/src/connection.C (file contents):
Revision 1.100 by root, Wed Jul 17 05:34:17 2013 UTC vs.
Revision 1.112 by root, Fri Sep 12 10:40:43 2014 UTC

… …
33 33
34#include <list> 34#include <list>
35#include <queue> 35#include <queue>
36#include <utility> 36#include <utility>
37 37
38#include <openssl/opensslv.h>
38#include <openssl/rand.h> 39#include <openssl/rand.h>
39#include <openssl/evp.h> 40#include <openssl/evp.h>
40#include <openssl/rsa.h> 41#include <openssl/rsa.h>
41#include <openssl/err.h> 42#include <openssl/err.h>
43
44// openssl 0.9.8 compatibility
45#if OPENSSL_VERSION_NUMBER < 0x10100000
46 #define require101(exp) exp
47#else
48 #define require101(exp) require (exp)
49#endif
42 50
43#include "conf.h" 51#include "conf.h"
44#include "slog.h" 52#include "slog.h"
45#include "device.h" 53#include "device.h"
46#include "vpn.h" 54#include "vpn.h"
… …
119 { 127 {
120 u8 mac_key[MAC_KEYSIZE]; 128 u8 mac_key[MAC_KEYSIZE];
121 static const unsigned char mac_info[] = "gvpe mac key"; 129 static const unsigned char mac_info[] = "gvpe mac key";
122 130
123 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ()); 131 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
124 kdf.extract (auth2.rsa.ikm, sizeof (auth2.rsa.ikm));
125 kdf.extract (auth1.rsa.mac_key, sizeof (auth1.rsa.mac_key)); 132 kdf.extract (auth1.rsa.mac_key, sizeof (auth1.rsa.mac_key));
126 kdf.extract (s, sizeof (s)); 133 kdf.extract (s, sizeof (s));
127 kdf.extract_done (HKDF_PRF_HASH ()); 134 kdf.extract_done (HKDF_PRF_HASH ());
128 kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info)); 135 kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info));
129 136
130 HMAC_CTX_init (&hctx); 137 HMAC_CTX_init (&hctx);
131 require (HMAC_Init_ex (&hctx, mac_key, MAC_KEYSIZE, MAC_DIGEST (), 0)); 138 require101 (HMAC_Init_ex (&hctx, mac_key, MAC_KEYSIZE, MAC_DIGEST (), 0));
132 } 139 }
133 140
134 { 141 {
135 u8 cipher_key[CIPHER_KEYSIZE]; 142 u8 cipher_key[CIPHER_KEYSIZE];
136 static const unsigned char cipher_info[] = "gvpe cipher key"; 143 static const unsigned char cipher_info[] = "gvpe cipher key";
137 144
138 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ()); 145 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
139 kdf.extract (auth2.rsa.ikm, sizeof (auth2.rsa.ikm));
140 kdf.extract (auth1.rsa.cipher_key, sizeof (auth1.rsa.cipher_key)); 146 kdf.extract (auth1.rsa.cipher_key, sizeof (auth1.rsa.cipher_key));
141 kdf.extract (s, sizeof (s)); 147 kdf.extract (s, sizeof (s));
142 kdf.extract_done (HKDF_PRF_HASH ()); 148 kdf.extract_done (HKDF_PRF_HASH ());
143 kdf.expand (cipher_key, sizeof (cipher_key), cipher_info, sizeof (cipher_info)); 149 kdf.expand (cipher_key, sizeof (cipher_key), cipher_info, sizeof (cipher_info));
144 150
… …
179 185
180 return 1; 186 return 1;
181} 187}
182 188
183static void 189static void
184auth_hash (const auth_data &auth, auth_mac &mac) 190auth_hash (const auth_data &auth, const ecdh_key &b, auth_mac &mac)
185{ 191{
186 HMAC_CTX ctx; 192 hkdf kdf (b, sizeof b, AUTH_DIGEST ()); // use response ecdh b as salt
187 193 kdf.extract (&auth.rsa, sizeof (auth.rsa));
188 HMAC_CTX_init (&ctx); 194 kdf.extract_done ();
189 require (HMAC_Init_ex (&ctx, auth.rsa.auth_key, sizeof (auth.rsa.auth_key), AUTH_DIGEST (), 0)); 195 kdf.expand (mac, sizeof mac, auth.ecdh, sizeof (auth.ecdh)); // use challenge ecdh b as info
190 require (HMAC_Update (&ctx, (const unsigned char *)&auth, sizeof auth));
191 require (HMAC_Final (&ctx, (unsigned char *)&mac, 0));
192 HMAC_CTX_cleanup (&ctx);
193} 196}
194 197
195void 198void
196connection::generate_auth_data () 199connection::generate_auth_data ()
197{ 200{
198 if (auth_expire < ev_now ()) 201 if (auth_expire < ev_now ())
199 { 202 {
200 // request data 203 // request data
201 RAND_bytes ((unsigned char *)&snd_auth.rsa, sizeof snd_auth.rsa); 204 rand_fill (snd_auth.rsa);
202 curve25519_generate (snd_ecdh_a, snd_auth.ecdh); 205 curve25519_generate (snd_ecdh_a, snd_auth.ecdh);
203 auth_hash (snd_auth, snd_auth_mac);
204 206
205 // eventual response data 207 // eventual response data
206 curve25519_generate (rcv_ecdh_a, rcv_ecdh_b); 208 curve25519_generate (rcv_ecdh_a, rcv_ecdh_b);
207 } 209 }
208 210
… …
364 } 366 }
365} 367}
366 368
367///////////////////////////////////////////////////////////////////////////// 369/////////////////////////////////////////////////////////////////////////////
368 370
369unsigned char hmac_packet::hmac_digest[EVP_MAX_MD_SIZE];
370
371void 371void
372hmac_packet::hmac_gen (crypto_ctx *ctx) 372hmac_packet::hmac_gen (crypto_ctx *ctx, u8 *hmac_digest)
373{ 373{
374 unsigned int xlen;
375
376 HMAC_CTX *hctx = &ctx->hctx; 374 HMAC_CTX *hctx = &ctx->hctx;
377 375
378 require (HMAC_Init_ex (hctx, 0, 0, 0, 0)); 376 require101 (HMAC_Init_ex (hctx, 0, 0, 0, 0));
379 require (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), 377 require101 (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet)));
380 len - sizeof (hmac_packet)));
381 require (HMAC_Final (hctx, (unsigned char *) &hmac_digest, &xlen)); 378 require101 (HMAC_Final (hctx, hmac_digest, 0));
382} 379}
383 380
384void 381void
385hmac_packet::hmac_set (crypto_ctx *ctx) 382hmac_packet::hmac_set (crypto_ctx *ctx)
386{ 383{
387 hmac_gen (ctx); 384 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
388 385 hmac_gen (ctx, hmac_digest);
389 memcpy (hmac, hmac_digest, HMACLENGTH); 386 memcpy (hmac, hmac_digest, HMACLENGTH);
390} 387}
391 388
392bool 389bool
393hmac_packet::hmac_chk (crypto_ctx *ctx) 390hmac_packet::hmac_chk (crypto_ctx *ctx)
394{ 391{
395 hmac_gen (ctx); 392 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
396 393 hmac_gen (ctx, hmac_digest);
397 return !memcmp (hmac, hmac_digest, HMACLENGTH); 394 return slow_memeq (hmac, hmac_digest, HMACLENGTH);
398} 395}
399 396
400void 397void
401vpn_packet::set_hdr (ptype type_, unsigned int dst) 398vpn_packet::set_hdr (ptype type_, unsigned int dst)
402{ 399{
… …
461 u32 seqno; 458 u32 seqno;
462 } datahdr; 459 } datahdr;
463 460
464 datahdr.seqno = ntohl (seqno); 461 datahdr.seqno = ntohl (seqno);
465#if RAND_SIZE 462#if RAND_SIZE
466 RAND_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE); 463 // NB: a constant (per session) random prefix
464 // is likely enough, but we don't take any chances.
465 conn->oiv.get (datahdr.rnd, RAND_SIZE);
467#endif 466#endif
468 467
469 require (EVP_EncryptUpdate (cctx, 468 require (EVP_EncryptUpdate (cctx,
470 (unsigned char *) data + outl, &outl2, 469 (unsigned char *) data + outl, &outl2,
471 (unsigned char *) &datahdr, DATAHDR)); 470 (unsigned char *) &datahdr, DATAHDR));
… …
502 501
503 if (type == PT_DATA_COMPRESSED) 502 if (type == PT_DATA_COMPRESSED)
504 d = cdata; 503 d = cdata;
505 else 504 else
506#endif 505#endif
507 d = &(*p)[6 + 6 - DATAHDR]; 506 d = &(*p)[6 + 6] - DATAHDR;
508 507
509 /* this overwrites part of the src mac, but we fix that later */ 508 // we play do evil games with the struct layout atm.
509 // pending better solutions, we at least do some verification.
510 // this is fine, as we left ISO territory long ago.
511 require (DATAHDR <= 16);
512 require ((u8 *)(&p->len + 1) == &(*p)[0]);
513
514 // this can overwrite the len/dst/src fields
510 require (EVP_DecryptUpdate (cctx, 515 require (EVP_DecryptUpdate (cctx,
511 d, &outl2, 516 d, &outl2,
512 (unsigned char *)&data, len - data_hdr_size ())); 517 (unsigned char *)&data, len - data_hdr_size ()));
513 outl += outl2; 518 outl += outl2;
514 519
… …
545 } 550 }
546}; 551};
547 552
548struct config_packet : vpn_packet 553struct config_packet : vpn_packet
549{ 554{
555 u8 serial[SERIAL_SIZE];
550 u8 prot_major, prot_minor, randsize; 556 u8 prot_major, prot_minor, randsize;
551 u8 flags, features, pad6, pad7, pad8; 557 u8 flags, features, pad6, pad7, pad8;
552 u32 cipher_nid, mac_nid, auth_nid; 558 u32 cipher_nid, mac_nid, auth_nid;
553 559
554 void setup (ptype type, int dst); 560 void setup (ptype type, int dst);
555 bool chk_config () const; 561 bool chk_config (const conf_node *conf, const sockinfo &rsi) const;
556 562
557 static u8 get_features () 563 static u8 get_features ()
558 { 564 {
559 u8 f = 0; 565 u8 f = 0;
560#if ENABLE_COMPRESSION 566#if ENABLE_COMPRESSION
… …
577 prot_minor = PROTOCOL_MINOR; 583 prot_minor = PROTOCOL_MINOR;
578 randsize = RAND_SIZE; 584 randsize = RAND_SIZE;
579 flags = 0; 585 flags = 0;
580 features = get_features (); 586 features = get_features ();
581 587
588 strncpy ((char *)serial, conf.serial, sizeof (serial));
589
582 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ())); 590 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ()));
583 mac_nid = htonl (EVP_MD_type (MAC_DIGEST ())); 591 mac_nid = htonl (EVP_MD_type (MAC_DIGEST ()));
584 auth_nid = htonl (EVP_MD_type (AUTH_DIGEST ())); 592 auth_nid = htonl (EVP_MD_type (AUTH_DIGEST ()));
585 593
586 len = sizeof (*this) - sizeof (net_packet); 594 len = sizeof (*this) - sizeof (net_packet);
587 set_hdr (type, dst); 595 set_hdr (type, dst);
588} 596}
589 597
590bool 598bool
591config_packet::chk_config () const 599config_packet::chk_config (const conf_node *conf, const sockinfo &rsi) const
592{ 600{
593 if (prot_major != PROTOCOL_MAJOR) 601 if (prot_major != PROTOCOL_MAJOR)
594 slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR); 602 slog (L_WARN, _("%s(%s): major version mismatch (remote %d <=> local %d)"),
603 conf->nodename, (const char *)rsi, prot_major, PROTOCOL_MAJOR);
595 else if (randsize != RAND_SIZE) 604 else if (randsize != RAND_SIZE)
596 slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE); 605 slog (L_WARN, _("%s(%s): rand size mismatch (remote %d <=> local %d)"),
606 conf->nodename, (const char *)rsi, randsize, RAND_SIZE);
597 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER ()))) 607 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER ())))
598 slog (L_WARN, _("cipher algo mismatch (remote %x <=> local %x)"), ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER ())); 608 slog (L_WARN, _("%s(%s): cipher algo mismatch (remote %x <=> local %x)"),
609 conf->nodename, (const char *)rsi, ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER ()));
599 else if (mac_nid != htonl (EVP_MD_type (MAC_DIGEST ()))) 610 else if (mac_nid != htonl (EVP_MD_type (MAC_DIGEST ())))
600 slog (L_WARN, _("mac algo mismatch (remote %x <=> local %x)"), ntohl (mac_nid), EVP_MD_type (MAC_DIGEST ())); 611 slog (L_WARN, _("%s(%s): mac algo mismatch (remote %x <=> local %x)"),
612 conf->nodename, (const char *)rsi, ntohl (mac_nid), EVP_MD_type (MAC_DIGEST ()));
601 else if (auth_nid != htonl (EVP_MD_type (AUTH_DIGEST ()))) 613 else if (auth_nid != htonl (EVP_MD_type (AUTH_DIGEST ())))
602 slog (L_WARN, _("auth algo mismatch (remote %x <=> local %x)"), ntohl (auth_nid), EVP_MD_type (AUTH_DIGEST ())); 614 slog (L_WARN, _("%s(%s): auth algo mismatch (remote %x <=> local %x)"),
615 conf->nodename, (const char *)rsi, ntohl (auth_nid), EVP_MD_type (AUTH_DIGEST ()));
603 else 616 else
617 {
618 int cmp = memcmp (serial, ::conf.serial, sizeof (serial));
619
620 if (cmp > 0)
621 slog (L_WARN, _("%s(%s): remote serial newer than local serial - outdated config?"),
622 conf->nodename, (const char *)rsi);
623 else if (cmp == 0)
604 return true; 624 return true;
625 }
605 626
606 return false; 627 return false;
607} 628}
608 629
609struct auth_req_packet : config_packet // UNPROTECTED 630struct auth_req_packet : config_packet // UNPROTECTED
… …
623 644
624 len = sizeof (*this) - sizeof (net_packet); 645 len = sizeof (*this) - sizeof (net_packet);
625 } 646 }
626}; 647};
627 648
628struct auth_res_packet : config_packet // UNPROTECTED 649struct auth_res_packet : vpn_packet // UNPROTECTED
629{ 650{
630 auth_response response; 651 auth_response response;
631 652
632 auth_res_packet (int dst) 653 auth_res_packet (int dst)
633 { 654 {
634 config_packet::setup (PT_AUTH_RES, dst); 655 set_hdr (PT_AUTH_RES, dst);
635 656
636 len = sizeof (*this) - sizeof (net_packet); 657 len = sizeof (*this) - sizeof (net_packet);
637 } 658 }
638}; 659};
639 660
… …
679 si = rsi; 700 si = rsi;
680 protocol = rsi.prot; 701 protocol = rsi.prot;
681 702
682 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."), 703 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
683 conf->nodename, (const char *)rsi, 704 conf->nodename, (const char *)rsi,
684 is_direct ? "direct" : "forwarded", 705 vpn->can_direct (THISNODE, conf) ? "direct" : "forwarded",
685 PROTOCOL_MAJOR, prot_minor); 706 PROTOCOL_MAJOR, prot_minor);
686 707
687 if (::conf.script_node_up) 708 if (::conf.script_node_up)
688 { 709 {
689 run_script_cb *cb = new run_script_cb; 710 run_script_cb *cb = new run_script_cb;
… …
695 iseqno.reset (ntohl (rcv_auth.rsa.seqno) & 0x7fffffff); 716 iseqno.reset (ntohl (rcv_auth.rsa.seqno) & 0x7fffffff);
696 717
697 delete octx; octx = new crypto_ctx (snd_auth, rcv_auth, snd_ecdh_a, snd_ecdh_b , 1); 718 delete octx; octx = new crypto_ctx (snd_auth, rcv_auth, snd_ecdh_a, snd_ecdh_b , 1);
698 oseqno = ntohl (snd_auth.rsa.seqno) & 0x7fffffff; 719 oseqno = ntohl (snd_auth.rsa.seqno) & 0x7fffffff;
699 720
700 if (ictx && octx) 721 oiv.reset ();
701 { 722
702 // make sure rekeying timeouts are slightly asymmetric 723 // make sure rekeying timeouts are slightly asymmetric
703 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0); 724 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0);
704 rekey.start (rekey_interval, rekey_interval); 725 rekey.start (rekey_interval, rekey_interval);
705 726
727 hmac_error = 0.;
728
706 keepalive.start (::conf.keepalive); 729 keepalive.start (::conf.keepalive);
707 730
708 // send queued packets 731 // send queued packets
709 if (ictx && octx)
710 {
711 while (tap_packet *p = (tap_packet *)data_queue.get ()) 732 while (tap_packet *p = (tap_packet *)data_queue.get ())
712 { 733 {
713 if (p->len) send_data_packet (p); 734 if (p->len) send_data_packet (p);
714 delete p; 735 delete p;
715 } 736 }
716 737
717 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) 738 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
718 { 739 {
719 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY); 740 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
720 delete p; 741 delete p;
721 } 742 }
722 }
723 743
724 vpn->connection_established (this); 744 vpn->connection_established (this);
725 }
726#if 0
727 else
728 {
729 retry_cnt = 0;
730 establish_connection.start (5);
731 keepalive.stop ();
732 rekey.stop ();
733 }
734#endif
735} 745}
736 746
737void 747void
738connection::reset_si () 748connection::reset_si ()
739{ 749{
… …
744 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename); 754 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename);
745 protocol = 0; 755 protocol = 0;
746 } 756 }
747 757
748 si.set (conf, protocol); 758 si.set (conf, protocol);
749
750 is_direct = si.valid ();
751} 759}
752 760
753// ensure sockinfo is valid, forward if necessary 761// ensure sockinfo is valid, forward if necessary
754const sockinfo & 762const sockinfo &
755connection::forward_si (const sockinfo &si) const 763connection::forward_si (const sockinfo &si) const
… …
774 782
775void 783void
776connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) 784connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
777{ 785{
778 if (!vpn->send_vpn_packet (pkt, si, tos)) 786 if (!vpn->send_vpn_packet (pkt, si, tos))
779 reset_connection (); 787 reset_connection ("packet send error");
780} 788}
781 789
782void 790void
783connection::send_ping (const sockinfo &si, u8 pong) 791connection::send_ping (const sockinfo &si, u8 pong)
784{ 792{
… …
823void 831void
824connection::send_auth_response (const sockinfo &si) 832connection::send_auth_response (const sockinfo &si)
825{ 833{
826 auth_res_packet *pkt = new auth_res_packet (conf->id); 834 auth_res_packet *pkt = new auth_res_packet (conf->id);
827 835
828 auth_hash (rcv_auth, pkt->response.mac);
829 memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof (rcv_ecdh_b)); 836 memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof rcv_ecdh_b);
837 auth_hash (rcv_auth, rcv_ecdh_b, pkt->response.mac);
830 838
831 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si); 839 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si);
832 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly 840 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly
833 841
834 delete pkt; 842 delete pkt;
… …
860 { 868 {
861 // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection 869 // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection
862 // and stop trying. should probably be handled by a per-connection expire handler. 870 // and stop trying. should probably be handled by a per-connection expire handler.
863 if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ()) 871 if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ())
864 { 872 {
865 reset_connection (); 873 reset_connection ("no demand");
866 return; 874 return;
867 } 875 }
868 876
869 last_establish_attempt = ev_now (); 877 last_establish_attempt = ev_now ();
870 878
… …
872 ? (retry_cnt & 3) + 1 880 ? (retry_cnt & 3) + 1
873 : 1 << (retry_cnt >> 2)); 881 : 1 << (retry_cnt >> 2));
874 882
875 reset_si (); 883 reset_si ();
876 884
877 bool slow = si.prot & PROT_SLOW; 885 bool slow = (si.prot & PROT_SLOW) || (conf->low_power || THISNODE->low_power);
878 886
879 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf)) 887 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf))
880 { 888 {
881 /*TODO*/ /* start the timer so we don't recurse endlessly */ 889 /*TODO*/ /* start the timer so we don't recurse endlessly */
882 w.start (1); 890 w.start (1);
… …
892 900
893 slow = slow || (dsi.prot & PROT_SLOW); 901 slow = slow || (dsi.prot & PROT_SLOW);
894 902
895 if (dsi.valid () && auth_rate_limiter.can (dsi)) 903 if (dsi.valid () && auth_rate_limiter.can (dsi))
896 { 904 {
897 if (retry_cnt < 4) 905 // use ping after the first few retries
906 // TODO: on rekeys, the other node might not interpret ping correctly,
907 // TODO: as it will still have a valid connection
908 if (retry_cnt < 4 && (!conf->low_power || THISNODE->low_power))
898 send_auth_request (dsi, true); 909 send_auth_request (dsi, true);
899 else 910 else
900 send_ping (dsi, 0); 911 send_ping (dsi, 0);
901 } 912 }
902 } 913 }
903 914
904 retry_int *= slow ? 8. : 0.9; 915 retry_int *= slow ? 4. : 0.9;
905 916
906 if (retry_int < conf->max_retry) 917 if (retry_int < conf->max_retry)
907 retry_cnt++; 918 retry_cnt++;
908 else 919 else
909 retry_int = conf->max_retry; 920 retry_int = conf->max_retry;
… …
911 w.start (retry_int); 922 w.start (retry_int);
912 } 923 }
913} 924}
914 925
915void 926void
916connection::reset_connection () 927connection::reset_connection (const char *reason)
917{ 928{
918 if (ictx && octx) 929 if (ictx && octx)
919 { 930 {
920 slog (L_INFO, _("%s(%s): connection lost"), 931 slog (L_INFO, _("%s(%s): connection lost (%s)"),
921 conf->nodename, (const char *)si); 932 conf->nodename, (const char *)si, reason);
922 933
923 if (::conf.script_node_down) 934 if (::conf.script_node_down)
924 { 935 {
925 run_script_cb *cb = new run_script_cb; 936 run_script_cb *cb = new run_script_cb;
926 cb->set<connection, &connection::script_node_down> (this); 937 cb->set<connection, &connection::script_node_down> (this);
… …
950connection::shutdown () 961connection::shutdown ()
951{ 962{
952 if (ictx && octx) 963 if (ictx && octx)
953 send_reset (si); 964 send_reset (si);
954 965
955 reset_connection (); 966 reset_connection ("shutdown");
956} 967}
957 968
958// poor-man's rekeying 969// poor-man's rekeying
959inline void 970inline void
960connection::rekey_cb (ev::timer &w, int revents) 971connection::rekey_cb (ev::timer &w, int revents)
961{ 972{
962 reset_connection (); 973 reset_connection ("rekeying");
963 establish_connection (); 974 establish_connection ();
964} 975}
965 976
966void 977void
967connection::send_data_packet (tap_packet *pkt) 978connection::send_data_packet (tap_packet *pkt)
… …
984 995
985void 996void
986connection::post_inject_queue () 997connection::post_inject_queue ()
987{ 998{
988 // force a connection every now and when when packets are sent (max 1/s) 999 // force a connection every now and when when packets are sent (max 1/s)
989 if (ev_now () - last_establish_attempt >= 0.95) // arbitrary 1000 if (ev_now () - last_establish_attempt >= (conf->low_power || THISNODE->low_power ? 2.95 : 0.95)) // arbitrary
990 establish_connection.stop (); 1001 establish_connection.stop ();
991 1002
992 establish_connection (); 1003 establish_connection ();
993} 1004}
994 1005
… …
1054 // about our desire for communication. 1065 // about our desire for communication.
1055 establish_connection (); 1066 establish_connection ();
1056 break; 1067 break;
1057 1068
1058 case vpn_packet::PT_RESET: 1069 case vpn_packet::PT_RESET:
1070 slog (L_TRACE, "%s >> PT_RESET", conf->nodename);
1071
1072 if (ictx && octx)
1059 { 1073 {
1060 reset_connection (); 1074 reset_connection ("remote reset");
1061 1075
1062 config_packet *p = (config_packet *) pkt; 1076 config_packet *p = (config_packet *) pkt;
1063 1077
1064 if (!p->chk_config ()) 1078 if (p->chk_config (conf, rsi) && connectmode == conf_node::C_ALWAYS)
1065 {
1066 slog (L_WARN, _("%s(%s): protocol mismatch, disabling node."),
1067 conf->nodename, (const char *)rsi);
1068 connectmode = conf_node::C_DISABLED;
1069 }
1070 else if (connectmode == conf_node::C_ALWAYS)
1071 establish_connection (); 1079 establish_connection ();
1072 } 1080 }
1081
1073 break; 1082 break;
1074 1083
1075 case vpn_packet::PT_AUTH_REQ: 1084 case vpn_packet::PT_AUTH_REQ:
1076 if (auth_rate_limiter.can (rsi)) 1085 if (auth_rate_limiter.can (rsi))
1077 { 1086 {
… …
1079 1088
1080 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s,p%02x,f%02x)", 1089 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s,p%02x,f%02x)",
1081 conf->nodename, p->initiate ? "initiate" : "reply", 1090 conf->nodename, p->initiate ? "initiate" : "reply",
1082 p->protocols, p->features); 1091 p->protocols, p->features);
1083 1092
1084 if (p->chk_config () && !memcmp (p->magic, MAGIC, 8)) 1093 if (memcmp (p->magic, MAGIC, 8))
1094 {
1095 slog (L_WARN, _("%s(%s): protocol magic mismatch - stray packet?"),
1096 conf->nodename, (const char *)rsi);
1097 }
1098 else if (p->chk_config (conf, rsi))
1085 { 1099 {
1086 if (p->prot_minor != PROTOCOL_MINOR) 1100 if (p->prot_minor != PROTOCOL_MINOR)
1087 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), 1101 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1088 conf->nodename, (const char *)rsi, 1102 conf->nodename, (const char *)rsi,
1089 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 1103 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1090 1104
1091 if (p->initiate) 1105 if (p->initiate)
1106 {
1092 send_auth_request (rsi, false); 1107 send_auth_request (rsi, false);
1108
1109 if (ictx && octx)
1110 reset_connection ("reconnect");
1111 }
1093 1112
1094 auth_data auth; 1113 auth_data auth;
1095 1114
1096 if (!auth_decrypt (::conf.rsa_key, p->encr, auth)) 1115 if (!auth_decrypt (::conf.rsa_key, p->encr, auth))
1097 { 1116 {
1098 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"), 1117 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"),
1099 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0)); 1118 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0));
1100 } 1119 }
1101 else 1120 else
1102 { 1121 {
1103 bool chg = !have_rcv_auth || memcmp (&rcv_auth, &auth, sizeof auth); 1122 bool chg = !have_rcv_auth || !slow_memeq (&rcv_auth, &auth, sizeof auth);
1104 1123
1105 rcv_auth = auth; 1124 rcv_auth = auth;
1106 have_rcv_auth = true; 1125 have_rcv_auth = true;
1107 1126
1108 send_auth_response (rsi); 1127 send_auth_response (rsi);
… …
1116 } 1135 }
1117 } 1136 }
1118 1137
1119 break; 1138 break;
1120 } 1139 }
1121 else
1122 slog (L_WARN, _("%s(%s): protocol mismatch."),
1123 conf->nodename, (const char *)rsi);
1124 1140
1125 send_reset (rsi); 1141 send_reset (rsi);
1126 } 1142 }
1127 1143
1128 break; 1144 break;
… …
1131 { 1147 {
1132 auth_res_packet *p = (auth_res_packet *)pkt; 1148 auth_res_packet *p = (auth_res_packet *)pkt;
1133 1149
1134 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename); 1150 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename);
1135 1151
1136 if (p->chk_config ()) 1152 auth_mac local_mac;
1153 auth_hash (snd_auth, p->response.ecdh, local_mac);
1154
1155 if (!slow_memeq (&p->response.mac, local_mac, sizeof local_mac))
1137 { 1156 {
1138 if (memcmp (&p->response.mac, snd_auth_mac, sizeof (snd_auth_mac)))
1139 {
1140 slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."), 1157 slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."),
1141 conf->nodename, (const char *)rsi); 1158 conf->nodename, (const char *)rsi);
1142 } 1159 }
1143 else if (!have_snd_auth) 1160 else if (!have_snd_auth)
1144 { 1161 {
1145 if (p->prot_minor != PROTOCOL_MINOR)
1146 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1147 conf->nodename, (const char *)rsi,
1148 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1149
1150 prot_minor = p->prot_minor;
1151 memcpy (snd_ecdh_b, p->response.ecdh, sizeof (snd_ecdh_b)); 1162 memcpy (snd_ecdh_b, p->response.ecdh, sizeof snd_ecdh_b);
1152 1163
1153 have_snd_auth = true; 1164 have_snd_auth = true;
1154 connection_established (rsi); 1165 connection_established (rsi);
1155 }
1156
1157 break;
1158 } 1166 }
1159 } 1167 }
1160
1161 send_reset (rsi);
1162 break; 1168 break;
1163 1169
1164 case vpn_packet::PT_DATA_COMPRESSED: 1170 case vpn_packet::PT_DATA_COMPRESSED:
1165#if !ENABLE_COMPRESSION 1171#if !ENABLE_COMPRESSION
1166 send_reset (rsi); 1172 send_reset (rsi);
… …
1172 if (ictx && octx) 1178 if (ictx && octx)
1173 { 1179 {
1174 vpndata_packet *p = (vpndata_packet *)pkt; 1180 vpndata_packet *p = (vpndata_packet *)pkt;
1175 1181
1176 if (!p->hmac_chk (ictx)) 1182 if (!p->hmac_chk (ictx))
1183 {
1184 // rekeying often creates temporary hmac auth floods
1185 // we assume they don't take longer than a few seconds normally,
1186 // and suppress messages and resets during that time.
1187 //TODO: should be done per source address
1188 if (!hmac_error)
1189 {
1190 hmac_error = ev_now () + 3;
1191 break;
1192 }
1193 else if (hmac_error >= ev_now ())
1194 break; // silently suppress
1195 else
1196 {
1177 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n" 1197 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
1178 "could be an attack, or just corruption or a synchronization error."), 1198 "could be an attack, or just corruption or a synchronization error."),
1179 conf->nodename, (const char *)rsi); 1199 conf->nodename, (const char *)rsi);
1200 // reset
1201 }
1202 }
1180 else 1203 else
1181 { 1204 {
1182 u32 seqno; 1205 u32 seqno;
1183 tap_packet *d = p->unpack (this, seqno); 1206 tap_packet *d = p->unpack (this, seqno);
1184 int seqclass = iseqno.seqno_classify (seqno); 1207 int seqclass = iseqno.seqno_classify (seqno);
1208
1209 hmac_error = 0;
1185 1210
1186 if (seqclass == 0) // ok 1211 if (seqclass == 0) // ok
1187 { 1212 {
1188 vpn->tap->send (d); 1213 vpn->tap->send (d);
1189 1214
… …
1316 1341
1317 if (when >= 0) 1342 if (when >= 0)
1318 w.start (when); 1343 w.start (when);
1319 else if (when < -15) 1344 else if (when < -15)
1320 { 1345 {
1321 reset_connection (); 1346 reset_connection ("keepalive overdue");
1322 establish_connection (); 1347 establish_connection ();
1323 } 1348 }
1324 else if (conf->connectmode != conf_node::C_ONDEMAND 1349 else if (conf->connectmode != conf_node::C_ONDEMAND
1325 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1350 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1326 { 1351 {
… …
1330 else if (when >= -10) 1355 else if (when >= -10)
1331 // hold ondemand connections implicitly a few seconds longer 1356 // hold ondemand connections implicitly a few seconds longer
1332 // should delete octx, though, or something like that ;) 1357 // should delete octx, though, or something like that ;)
1333 w.start (when + 10); 1358 w.start (when + 10);
1334 else 1359 else
1335 reset_connection (); 1360 reset_connection ("keepalive timeout");
1336} 1361}
1337 1362
1338void 1363void
1339connection::send_connect_request (int id) 1364connection::send_connect_request (int id)
1340{ 1365{
… …
1440 1465
1441 // queue a dummy packet to force an initial connection attempt 1466 // queue a dummy packet to force an initial connection attempt
1442 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED) 1467 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED)
1443 vpn_queue.put (new net_packet); 1468 vpn_queue.put (new net_packet);
1444 1469
1445 reset_connection (); 1470 reset_connection ("startup");
1446} 1471}
1447 1472
1448connection::~connection () 1473connection::~connection ()
1449{ 1474{
1450 shutdown (); 1475 shutdown ();

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