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Comparing gvpe/src/connection.C (file contents):
Revision 1.91 by root, Tue Feb 8 23:13:48 2011 UTC vs.
Revision 1.105 by root, Fri Jul 19 18:22:54 2013 UTC

1/* 1/*
2 connection.C -- manage a single connection 2 connection.C -- manage a single connection
3 Copyright (C) 2003-2008,2010 Marc Lehmann <gvpe@schmorp.de> 3 Copyright (C) 2003-2008,2010,2011,2013 Marc Lehmann <gvpe@schmorp.de>
4 4
5 This file is part of GVPE. 5 This file is part of GVPE.
6 6
7 GVPE is free software; you can redistribute it and/or modify it 7 GVPE is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the 8 under the terms of the GNU General Public License as published by the
… …
43#include "conf.h" 43#include "conf.h"
44#include "slog.h" 44#include "slog.h"
45#include "device.h" 45#include "device.h"
46#include "vpn.h" 46#include "vpn.h"
47#include "connection.h" 47#include "connection.h"
48#include "hkdf.h"
48 49
49#include "netcompat.h" 50#include "netcompat.h"
50 51
51#if !HAVE_RAND_PSEUDO_BYTES
52# define RAND_pseudo_bytes RAND_bytes
53#endif
54
55#define MAGIC_OLD "vped\xbd\xc6\xdb\x82" // 8 bytes of magic (still used in the protocol)
56#define MAGIC "gvpe\xbd\xc6\xdb\x82" // 8 bytes of magic (understood but not generated) 52#define MAGIC "gvpe\xbd\xc6\xdb\x82" // 8 bytes of magic
53#define MAGIC "HUHN\xbd\xc6\xdb\x82" // 8 bytes of magic//D
57 54
58#define ULTRA_FAST 1 55#define ULTRA_FAST 1
59#define HLOG 15 56#define HLOG 15
60#include "lzf/lzf.h" 57#include "lzf/lzf.h"
61#include "lzf/lzf_c.c" 58#include "lzf/lzf_c.c"
… …
108struct crypto_ctx 105struct crypto_ctx
109{ 106{
110 EVP_CIPHER_CTX cctx; 107 EVP_CIPHER_CTX cctx;
111 HMAC_CTX hctx; 108 HMAC_CTX hctx;
112 109
113 crypto_ctx (const rsachallenge &challenge, int enc); 110 crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc);
114 ~crypto_ctx (); 111 ~crypto_ctx ();
115}; 112};
116 113
117crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc) 114crypto_ctx::crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc)
118{ 115{
116 ecdh_key s;
117
118 curve25519_combine (a, b, s);
119
120 {
121 u8 mac_key[MAC_KEYSIZE];
122 static const unsigned char mac_info[] = "gvpe mac key";
123
124 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
125 kdf.extract (auth1.rsa.mac_key, sizeof (auth1.rsa.mac_key));
126 kdf.extract (s, sizeof (s));
127 kdf.extract_done (HKDF_PRF_HASH ());
128 kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info));
129
130 HMAC_CTX_init (&hctx);
131 require (HMAC_Init_ex (&hctx, mac_key, MAC_KEYSIZE, MAC_DIGEST (), 0));
132 }
133
134 {
135 u8 cipher_key[CIPHER_KEYSIZE];
136 static const unsigned char cipher_info[] = "gvpe cipher key";
137
138 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
139 kdf.extract (auth1.rsa.cipher_key, sizeof (auth1.rsa.cipher_key));
140 kdf.extract (s, sizeof (s));
141 kdf.extract_done (HKDF_PRF_HASH ());
142 kdf.expand (cipher_key, sizeof (cipher_key), cipher_info, sizeof (cipher_info));
143
119 EVP_CIPHER_CTX_init (&cctx); 144 EVP_CIPHER_CTX_init (&cctx);
120 require (EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc)); 145 require (EVP_CipherInit_ex (&cctx, CIPHER (), 0, cipher_key, 0, enc));
121 HMAC_CTX_init (&hctx); 146 }
122 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
123} 147}
124 148
125crypto_ctx::~crypto_ctx () 149crypto_ctx::~crypto_ctx ()
126{ 150{
127 require (EVP_CIPHER_CTX_cleanup (&cctx)); 151 require (EVP_CIPHER_CTX_cleanup (&cctx));
128 HMAC_CTX_cleanup (&hctx); 152 HMAC_CTX_cleanup (&hctx);
129} 153}
130 154
155static inline void
156auth_encrypt (RSA *key, const auth_data &auth, auth_encr &encr)
157{
158 if (RSA_public_encrypt (sizeof (auth.rsa),
159 (unsigned char *)&auth.rsa, (unsigned char *)&encr.rsa,
160 key, RSA_PKCS1_OAEP_PADDING) < 0)
161 fatal ("RSA_public_encrypt error");
162
163 memcpy (&encr.ecdh, &auth.ecdh, sizeof (encr.ecdh));
164}
165
166static inline bool
167auth_decrypt (RSA *key, const auth_encr &encr, auth_data &auth)
168{
169 u8 rsa_decrypt[RSA_KEYLEN];
170
171 if (RSA_private_decrypt (sizeof (encr.rsa),
172 (const unsigned char *)&encr.rsa, (unsigned char *)rsa_decrypt,
173 key, RSA_PKCS1_OAEP_PADDING) != sizeof (auth.rsa))
174 return 0;
175
176 memcpy (&auth.rsa, rsa_decrypt, sizeof (auth.rsa));
177 memcpy (&auth.ecdh, &encr.ecdh, sizeof (auth.ecdh));
178
179 return 1;
180}
181
131static void 182static void
132rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h) 183auth_hash (const auth_data &auth, const ecdh_key &b, auth_mac &mac)
133{ 184{
134 EVP_MD_CTX ctx; 185 hkdf kdf (&auth.ecdh, sizeof (auth.ecdh), AUTH_DIGEST ()); // use remote ecdh b as salt
135 186 kdf.extract (&auth.rsa, sizeof (auth.rsa));
136 EVP_MD_CTX_init (&ctx); 187 kdf.extract_done ();
137 require (EVP_DigestInit (&ctx, RSA_HASH)); 188 kdf.expand (mac, sizeof mac, b, sizeof b); // use response ecdh b as info
138 require (EVP_DigestUpdate(&ctx, &chg, sizeof chg));
139 require (EVP_DigestUpdate(&ctx, &id, sizeof id));
140 require (EVP_DigestFinal (&ctx, (unsigned char *)&h, 0));
141 EVP_MD_CTX_cleanup (&ctx);
142} 189}
143 190
144struct rsa_entry 191void
192connection::generate_auth_data ()
145{ 193{
146 tstamp expire; 194 if (auth_expire < ev_now ())
147 rsaid id;
148 rsachallenge chg;
149};
150
151struct rsa_cache : list<rsa_entry>
152{
153 inline void cleaner_cb (ev::timer &w, int revents); ev::timer cleaner;
154
155 bool find (const rsaid &id, rsachallenge &chg)
156 {
157 for (iterator i = begin (); i != end (); ++i)
158 { 195 {
159 if (!memcmp (&id, &i->id, sizeof id) && i->expire > ev_now ()) 196 // request data
160 { 197 rand_fill (snd_auth.rsa);
161 memcpy (&chg, &i->chg, sizeof chg); 198 curve25519_generate (snd_ecdh_a, snd_auth.ecdh);
162 199
163 erase (i); 200 // eventual response data
164 return true; 201 curve25519_generate (rcv_ecdh_a, rcv_ecdh_b);
165 }
166 } 202 }
167 203
168 if (!cleaner.is_active ()) 204 // every use prolongs the expiry
169 cleaner.again ();
170
171 return false;
172 }
173
174 void gen (rsaid &id, rsachallenge &chg)
175 {
176 rsa_entry e;
177
178 RAND_bytes ((unsigned char *)&id, sizeof id);
179 RAND_bytes ((unsigned char *)&chg, sizeof chg);
180
181 e.expire = ev_now () + RSA_TTL; 205 auth_expire = ev_now () + AUTH_TTL;
182 e.id = id;
183 memcpy (&e.chg, &chg, sizeof chg);
184
185 push_back (e);
186
187 if (!cleaner.is_active ())
188 cleaner.again ();
189 }
190
191 rsa_cache ()
192 {
193 cleaner.set<rsa_cache, &rsa_cache::cleaner_cb> (this);
194 cleaner.set (RSA_TTL, RSA_TTL);
195 }
196
197} rsa_cache;
198
199void
200rsa_cache::cleaner_cb (ev::timer &w, int revents)
201{
202 if (empty ())
203 w.stop ();
204 else
205 {
206 for (iterator i = begin (); i != end (); )
207 if (i->expire <= ev_now ())
208 i = erase (i);
209 else
210 ++i;
211 }
212} 206}
213 207
214////////////////////////////////////////////////////////////////////////////// 208//////////////////////////////////////////////////////////////////////////////
215 209
216pkt_queue::pkt_queue (double max_ttl, int max_queue) 210pkt_queue::pkt_queue (double max_ttl, int max_queue)
… …
365 } 359 }
366} 360}
367 361
368///////////////////////////////////////////////////////////////////////////// 362/////////////////////////////////////////////////////////////////////////////
369 363
370unsigned char hmac_packet::hmac_digest[EVP_MAX_MD_SIZE];
371
372void 364void
373hmac_packet::hmac_gen (crypto_ctx *ctx) 365hmac_packet::hmac_gen (crypto_ctx *ctx, u8 *hmac_digest)
374{ 366{
375 unsigned int xlen;
376
377 HMAC_CTX *hctx = &ctx->hctx; 367 HMAC_CTX *hctx = &ctx->hctx;
378 368
379 HMAC_Init_ex (hctx, 0, 0, 0, 0); 369 require (HMAC_Init_ex (hctx, 0, 0, 0, 0));
380 HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), 370 require (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet)));
381 len - sizeof (hmac_packet)); 371 require (HMAC_Final (hctx, hmac_digest, 0));
382 HMAC_Final (hctx, (unsigned char *) &hmac_digest, &xlen);
383} 372}
384 373
385void 374void
386hmac_packet::hmac_set (crypto_ctx *ctx) 375hmac_packet::hmac_set (crypto_ctx *ctx)
387{ 376{
388 hmac_gen (ctx); 377 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
389 378 hmac_gen (ctx, hmac_digest);
390 memcpy (hmac, hmac_digest, HMACLENGTH); 379 memcpy (hmac, hmac_digest, HMACLENGTH);
391} 380}
392 381
393bool 382bool
394hmac_packet::hmac_chk (crypto_ctx *ctx) 383hmac_packet::hmac_chk (crypto_ctx *ctx)
395{ 384{
396 hmac_gen (ctx); 385 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
397 386 hmac_gen (ctx, hmac_digest);
398 return !memcmp (hmac, hmac_digest, HMACLENGTH); 387 return !memcmp (hmac, hmac_digest, HMACLENGTH);
399} 388}
400 389
401void 390void
402vpn_packet::set_hdr (ptype type_, unsigned int dst) 391vpn_packet::set_hdr (ptype type_, unsigned int dst)
… …
451 d[1] = cl; 440 d[1] = cl;
452 } 441 }
453 } 442 }
454#endif 443#endif
455 444
456 require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0)); 445 require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 1));
457 446
458 struct { 447 struct {
459#if RAND_SIZE 448#if RAND_SIZE
460 u8 rnd[RAND_SIZE]; 449 u8 rnd[RAND_SIZE];
461#endif 450#endif
462 u32 seqno; 451 u32 seqno;
463 } datahdr; 452 } datahdr;
464 453
465 datahdr.seqno = ntohl (seqno); 454 datahdr.seqno = ntohl (seqno);
466#if RAND_SIZE 455#if RAND_SIZE
467 RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE); 456 // NB: a constant (per session) random prefix
457 // is likely enough, but we don't take any chances.
458 conn->oiv.get (datahdr.rnd, RAND_SIZE);
468#endif 459#endif
469 460
470 require (EVP_EncryptUpdate (cctx, 461 require (EVP_EncryptUpdate (cctx,
471 (unsigned char *) data + outl, &outl2, 462 (unsigned char *) data + outl, &outl2,
472 (unsigned char *) &datahdr, DATAHDR)); 463 (unsigned char *) &datahdr, DATAHDR));
… …
494 int outl = 0, outl2; 485 int outl = 0, outl2;
495 tap_packet *p = new tap_packet; 486 tap_packet *p = new tap_packet;
496 u8 *d; 487 u8 *d;
497 u32 l = len - data_hdr_size (); 488 u32 l = len - data_hdr_size ();
498 489
499 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, 0)); 490 require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 0));
500 491
501#if ENABLE_COMPRESSION 492#if ENABLE_COMPRESSION
502 u8 cdata[MAX_MTU]; 493 u8 cdata[MAX_MTU];
503 494
504 if (type == PT_DATA_COMPRESSED) 495 if (type == PT_DATA_COMPRESSED)
505 d = cdata; 496 d = cdata;
506 else 497 else
507#endif 498#endif
508 d = &(*p)[6 + 6 - DATAHDR]; 499 d = &(*p)[6 + 6] - DATAHDR;
509 500
510 /* this overwrites part of the src mac, but we fix that later */ 501 // we play do evil games with the struct layout atm.
502 // pending better solutions, we at least do some verification.
503 // this is fine, as we left ISO territory long ago.
504 require (DATAHDR <= 16);
505 require ((u8 *)(&p->len + 1) == &(*p)[0]);
506
507 // this can overwrite the len/dst/src fields
511 require (EVP_DecryptUpdate (cctx, 508 require (EVP_DecryptUpdate (cctx,
512 d, &outl2, 509 d, &outl2,
513 (unsigned char *)&data, len - data_hdr_size ())); 510 (unsigned char *)&data, len - data_hdr_size ()));
514 outl += outl2; 511 outl += outl2;
515 512
… …
546 } 543 }
547}; 544};
548 545
549struct config_packet : vpn_packet 546struct config_packet : vpn_packet
550{ 547{
551 // actually, hmaclen cannot be checked because the hmac 548 u8 serial[SERIAL_SIZE];
552 // field comes before this data, so peers with other
553 // hmacs simply will not work.
554 u8 prot_major, prot_minor, randsize, hmaclen; 549 u8 prot_major, prot_minor, randsize;
555 u8 flags, challengelen, features, pad3; 550 u8 flags, features, pad6, pad7, pad8;
556 u32 cipher_nid, digest_nid, hmac_nid; 551 u32 cipher_nid, mac_nid, auth_nid;
557 552
558 void setup (ptype type, int dst); 553 void setup (ptype type, int dst);
559 bool chk_config () const; 554 bool chk_config (const conf_node *conf, const sockinfo &rsi) const;
560 555
561 static u8 get_features () 556 static u8 get_features ()
562 { 557 {
563 u8 f = 0; 558 u8 f = 0;
564#if ENABLE_COMPRESSION 559#if ENABLE_COMPRESSION
… …
578config_packet::setup (ptype type, int dst) 573config_packet::setup (ptype type, int dst)
579{ 574{
580 prot_major = PROTOCOL_MAJOR; 575 prot_major = PROTOCOL_MAJOR;
581 prot_minor = PROTOCOL_MINOR; 576 prot_minor = PROTOCOL_MINOR;
582 randsize = RAND_SIZE; 577 randsize = RAND_SIZE;
583 hmaclen = HMACLENGTH;
584 flags = 0; 578 flags = 0;
585 challengelen = sizeof (rsachallenge);
586 features = get_features (); 579 features = get_features ();
587 580
581 strncpy ((char *)serial, conf.serial, sizeof (serial));
582
588 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER)); 583 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ()));
589 digest_nid = htonl (EVP_MD_type (RSA_HASH));
590 hmac_nid = htonl (EVP_MD_type (DIGEST)); 584 mac_nid = htonl (EVP_MD_type (MAC_DIGEST ()));
585 auth_nid = htonl (EVP_MD_type (AUTH_DIGEST ()));
591 586
592 len = sizeof (*this) - sizeof (net_packet); 587 len = sizeof (*this) - sizeof (net_packet);
593 set_hdr (type, dst); 588 set_hdr (type, dst);
594} 589}
595 590
596bool 591bool
597config_packet::chk_config () const 592config_packet::chk_config (const conf_node *conf, const sockinfo &rsi) const
598{ 593{
599 if (prot_major != PROTOCOL_MAJOR) 594 if (prot_major != PROTOCOL_MAJOR)
600 slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR); 595 slog (L_WARN, _("%s(%s): major version mismatch (remote %d <=> local %d)"),
596 conf->nodename, (const char *)rsi, prot_major, PROTOCOL_MAJOR);
601 else if (randsize != RAND_SIZE) 597 else if (randsize != RAND_SIZE)
602 slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE); 598 slog (L_WARN, _("%s(%s): rand size mismatch (remote %d <=> local %d)"),
603 else if (hmaclen != HMACLENGTH) 599 conf->nodename, (const char *)rsi, randsize, RAND_SIZE);
604 slog (L_WARN, _("hmac length mismatch (remote %d <=> local %d)"), hmaclen, HMACLENGTH);
605 else if (challengelen != sizeof (rsachallenge))
606 slog (L_WARN, _("challenge length mismatch (remote %d <=> local %d)"), challengelen, sizeof (rsachallenge));
607 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER))) 600 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER ())))
608 slog (L_WARN, _("cipher mismatch (remote %x <=> local %x)"), ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER)); 601 slog (L_WARN, _("%s(%s): cipher algo mismatch (remote %x <=> local %x)"),
609 else if (digest_nid != htonl (EVP_MD_type (RSA_HASH))) 602 conf->nodename, (const char *)rsi, ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER ()));
610 slog (L_WARN, _("digest mismatch (remote %x <=> local %x)"), ntohl (digest_nid), EVP_MD_type (RSA_HASH));
611 else if (hmac_nid != htonl (EVP_MD_type (DIGEST))) 603 else if (mac_nid != htonl (EVP_MD_type (MAC_DIGEST ())))
612 slog (L_WARN, _("hmac mismatch (remote %x <=> local %x)"), ntohl (hmac_nid), EVP_MD_type (DIGEST)); 604 slog (L_WARN, _("%s(%s): mac algo mismatch (remote %x <=> local %x)"),
605 conf->nodename, (const char *)rsi, ntohl (mac_nid), EVP_MD_type (MAC_DIGEST ()));
606 else if (auth_nid != htonl (EVP_MD_type (AUTH_DIGEST ())))
607 slog (L_WARN, _("%s(%s): auth algo mismatch (remote %x <=> local %x)"),
608 conf->nodename, (const char *)rsi, ntohl (auth_nid), EVP_MD_type (AUTH_DIGEST ()));
613 else 609 else
610 {
611 int cmp = memcmp (serial, ::conf.serial, sizeof (serial));
612
613 if (cmp > 0)
614 slog (L_WARN, _("%s(%s): remote serial newer than local serial - outdated config?"),
615 conf->nodename, (const char *)rsi);
616 else if (cmp == 0)
614 return true; 617 return true;
618 }
615 619
616 return false; 620 return false;
617} 621}
618 622
619struct auth_req_packet : config_packet 623struct auth_req_packet : config_packet // UNPROTECTED
620{ 624{
621 char magic[8]; 625 char magic[8];
622 u8 initiate; // false if this is just an automatic reply 626 u8 initiate; // false if this is just an automatic reply
623 u8 protocols; // supported protocols (will be patched on forward) 627 u8 protocols; // supported protocols (will be patched on forward)
624 u8 pad2, pad3; 628 u8 pad2, pad3;
625 rsaid id; 629 auth_encr encr;
626 rsaencrdata encr;
627 630
628 auth_req_packet (int dst, bool initiate_, u8 protocols_) 631 auth_req_packet (int dst, bool initiate_, u8 protocols_)
629 { 632 {
630 config_packet::setup (PT_AUTH_REQ, dst); 633 config_packet::setup (PT_AUTH_REQ, dst);
631 strncpy (magic, MAGIC_OLD, 8); 634 memcpy (magic, MAGIC, 8);
632 initiate = !!initiate_; 635 initiate = !!initiate_;
633 protocols = protocols_; 636 protocols = protocols_;
634 637
635 len = sizeof (*this) - sizeof (net_packet); 638 len = sizeof (*this) - sizeof (net_packet);
636 } 639 }
637}; 640};
638 641
639struct auth_res_packet : config_packet 642struct auth_res_packet : vpn_packet // UNPROTECTED
640{ 643{
641 rsaid id;
642 u8 pad1, pad2, pad3;
643 u8 response_len; // encrypted length
644 rsaresponse response; 644 auth_response response;
645 645
646 auth_res_packet (int dst) 646 auth_res_packet (int dst)
647 { 647 {
648 config_packet::setup (PT_AUTH_RES, dst); 648 set_hdr (PT_AUTH_RES, dst);
649 649
650 len = sizeof (*this) - sizeof (net_packet); 650 len = sizeof (*this) - sizeof (net_packet);
651 } 651 }
652}; 652};
653 653
… …
683}; 683};
684 684
685///////////////////////////////////////////////////////////////////////////// 685/////////////////////////////////////////////////////////////////////////////
686 686
687void 687void
688connection::connection_established () 688connection::connection_established (const sockinfo &rsi)
689{ 689{
690 slog (L_NOISE, _("%s: possible connection establish (ictx %d, octx %d)"), conf->nodename, !!ictx, !!octx); 690 if (!have_snd_auth || !have_rcv_auth)
691 return;
691 692
693 si = rsi;
694 protocol = rsi.prot;
695
696 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
697 conf->nodename, (const char *)rsi,
698 is_direct ? "direct" : "forwarded",
699 PROTOCOL_MAJOR, prot_minor);
700
701 if (::conf.script_node_up)
702 {
703 run_script_cb *cb = new run_script_cb;
704 cb->set<connection, &connection::script_node_up> (this);
705 run_script_queued (cb, _("node-up command execution failed, continuing."));
706 }
707
708 delete ictx; ictx = new crypto_ctx (rcv_auth, snd_auth, rcv_ecdh_a, rcv_auth.ecdh, 0);
709 iseqno.reset (ntohl (rcv_auth.rsa.seqno) & 0x7fffffff);
710
711 delete octx; octx = new crypto_ctx (snd_auth, rcv_auth, snd_ecdh_a, snd_ecdh_b , 1);
712 oseqno = ntohl (snd_auth.rsa.seqno) & 0x7fffffff;
713
714 oiv.reset ();
715
716 // make sure rekeying timeouts are slightly asymmetric
717 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0);
718 rekey.start (rekey_interval, rekey_interval);
719
720 keepalive.start (::conf.keepalive);
721
722 // send queued packets
692 if (ictx && octx) 723 if (ictx && octx)
693 { 724 {
694 // make sure rekeying timeouts are slightly asymmetric 725 while (tap_packet *p = (tap_packet *)data_queue.get ())
695 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0);
696 rekey.start (rekey_interval, rekey_interval);
697 keepalive.start (::conf.keepalive);
698
699 // send queued packets
700 if (ictx && octx)
701 { 726 {
702 while (tap_packet *p = (tap_packet *)data_queue.get ())
703 {
704 if (p->len) send_data_packet (p); 727 if (p->len) send_data_packet (p);
705 delete p; 728 delete p;
706 }
707
708 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
709 {
710 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
711 delete p;
712 }
713 } 729 }
714 730
731 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
732 {
733 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
734 delete p;
735 }
736 }
737
715 vpn->connection_established (this); 738 vpn->connection_established (this);
716 }
717 else
718 {
719 retry_cnt = 0;
720 establish_connection.start (5);
721 keepalive.stop ();
722 rekey.stop ();
723 }
724} 739}
725 740
726void 741void
727connection::reset_si () 742connection::reset_si ()
728{ 743{
… …
774 ping_packet *pkt = new ping_packet; 789 ping_packet *pkt = new ping_packet;
775 790
776 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING); 791 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING);
777 792
778 slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si); 793 slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si);
779
780 send_vpn_packet (pkt, si, IPTOS_LOWDELAY); 794 send_vpn_packet (pkt, si, IPTOS_LOWDELAY);
781 795
782 delete pkt; 796 delete pkt;
783} 797}
784 798
… …
799void 813void
800connection::send_auth_request (const sockinfo &si, bool initiate) 814connection::send_auth_request (const sockinfo &si, bool initiate)
801{ 815{
802 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols); 816 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols);
803 817
804 rsachallenge chg; 818 generate_auth_data ();
805 rsa_cache.gen (pkt->id, chg);
806 rsa_encrypt (conf->rsa_key, chg, pkt->encr); 819 auth_encrypt (conf->rsa_key, snd_auth, pkt->encr);
807 820
808 slog (L_TRACE, "%s << PT_AUTH_REQ [%s]", conf->nodename, (const char *)si); 821 slog (L_TRACE, "%s << PT_AUTH_REQ [%s]", conf->nodename, (const char *)si);
809
810 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly 822 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly
811 823
812 delete pkt; 824 delete pkt;
813} 825}
814 826
815void 827void
816connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg) 828connection::send_auth_response (const sockinfo &si)
817{ 829{
818 auth_res_packet *pkt = new auth_res_packet (conf->id); 830 auth_res_packet *pkt = new auth_res_packet (conf->id);
819 831
820 pkt->id = id; 832 memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof rcv_ecdh_b);
821 833 auth_hash (rcv_auth, rcv_ecdh_b, pkt->response.mac);
822 rsa_hash (id, chg, pkt->response);
823
824 pkt->hmac_set (octx);
825 834
826 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si); 835 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si);
827
828 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly 836 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly
829 837
830 delete pkt; 838 delete pkt;
831} 839}
832 840
833void 841void
834connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols) 842connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols)
835{ 843{
836 slog (L_TRACE, "%s << PT_CONNECT_INFO(%s,%s)", conf->nodename, 844 slog (L_TRACE, "%s << PT_CONNECT_INFO(%s,%s,p%02x)", conf->nodename,
837 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi); 845 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi,
846 conf->protocols);
838 847
839 connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols); 848 connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols);
840 849
841 r->hmac_set (octx); 850 r->hmac_set (octx);
842 send_vpn_packet (r, si); 851 send_vpn_packet (r, si);
… …
845} 854}
846 855
847inline void 856inline void
848connection::establish_connection_cb (ev::timer &w, int revents) 857connection::establish_connection_cb (ev::timer &w, int revents)
849{ 858{
850 if (!ictx 859 if (!(ictx && octx)
851 && conf != THISNODE 860 && conf != THISNODE
852 && connectmode != conf_node::C_NEVER 861 && connectmode != conf_node::C_NEVER
853 && connectmode != conf_node::C_DISABLED 862 && connectmode != conf_node::C_DISABLED
854 && !w.is_active ()) 863 && !w.is_active ())
855 { 864 {
… …
923 } 932 }
924 } 933 }
925 934
926 delete ictx; ictx = 0; 935 delete ictx; ictx = 0;
927 delete octx; octx = 0; 936 delete octx; octx = 0;
928#if ENABLE_DNS
929 dnsv4_reset_connection ();
930#endif
931 937
932 si.host = 0; 938 si.host = 0;
939
940 have_snd_auth = false;
941 have_rcv_auth = false;
942 auth_expire = 0.;
933 943
934 last_activity = 0.; 944 last_activity = 0.;
935 //last_si_change = 0.; 945 //last_si_change = 0.;
936 retry_cnt = 0; 946 retry_cnt = 0;
937 947
… …
1053 { 1063 {
1054 reset_connection (); 1064 reset_connection ();
1055 1065
1056 config_packet *p = (config_packet *) pkt; 1066 config_packet *p = (config_packet *) pkt;
1057 1067
1058 if (!p->chk_config ()) 1068 if (p->chk_config (conf, rsi) && connectmode == conf_node::C_ALWAYS)
1059 {
1060 slog (L_WARN, _("%s(%s): protocol mismatch, disabling node."),
1061 conf->nodename, (const char *)rsi);
1062 connectmode = conf_node::C_DISABLED;
1063 }
1064 else if (connectmode == conf_node::C_ALWAYS)
1065 establish_connection (); 1069 establish_connection ();
1066 } 1070 }
1067 break; 1071 break;
1068 1072
1069 case vpn_packet::PT_AUTH_REQ: 1073 case vpn_packet::PT_AUTH_REQ:
1070 if (auth_rate_limiter.can (rsi)) 1074 if (auth_rate_limiter.can (rsi))
1071 { 1075 {
1072 auth_req_packet *p = (auth_req_packet *) pkt; 1076 auth_req_packet *p = (auth_req_packet *)pkt;
1073 1077
1074 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s)", conf->nodename, p->initiate ? "initiate" : "reply"); 1078 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s,p%02x,f%02x)",
1079 conf->nodename, p->initiate ? "initiate" : "reply",
1080 p->protocols, p->features);
1075 1081
1082 if (memcmp (p->magic, MAGIC, 8))
1083 {
1084 slog (L_WARN, _("%s(%s): protocol magic mismatch - stray packet?"),
1085 conf->nodename, (const char *)rsi);
1086 }
1076 if (p->chk_config () 1087 else if (p->chk_config (conf, rsi))
1077 && (!strncmp (p->magic, MAGIC_OLD, 8) || !strncmp (p->magic, MAGIC, 8)))
1078 { 1088 {
1079 if (p->prot_minor != PROTOCOL_MINOR) 1089 if (p->prot_minor != PROTOCOL_MINOR)
1080 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), 1090 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1081 conf->nodename, (const char *)rsi, 1091 conf->nodename, (const char *)rsi,
1082 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 1092 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1083 1093
1084 if (p->initiate) 1094 if (p->initiate)
1085 send_auth_request (rsi, false); 1095 send_auth_request (rsi, false);
1086 1096
1087 rsachallenge k; 1097 auth_data auth;
1088 1098
1089 if (!rsa_decrypt (::conf.rsa_key, p->encr, k)) 1099 if (!auth_decrypt (::conf.rsa_key, p->encr, auth))
1090 { 1100 {
1091 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"), 1101 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"),
1092 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0)); 1102 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0));
1093 break;
1094 } 1103 }
1095 else 1104 else
1096 { 1105 {
1097 delete octx; 1106 bool chg = !have_rcv_auth || memcmp (&rcv_auth, &auth, sizeof auth);
1098 1107
1099 octx = new crypto_ctx (k, 1); 1108 rcv_auth = auth;
1100 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; 1109 have_rcv_auth = true;
1101 1110
1111 send_auth_response (rsi);
1112
1113 if (chg)
1114 {
1102 conf->protocols = p->protocols; 1115 conf->protocols = p->protocols;
1103 features = p->features & config_packet::get_features (); 1116 features = p->features & config_packet::get_features ();
1104 1117
1105 send_auth_response (rsi, p->id, k);
1106
1107 connection_established (); 1118 connection_established (rsi);
1108
1109 break; 1119 }
1110 } 1120 }
1121
1122 break;
1111 } 1123 }
1112 else
1113 slog (L_WARN, _("%s(%s): protocol mismatch."),
1114 conf->nodename, (const char *)rsi);
1115 1124
1116 send_reset (rsi); 1125 send_reset (rsi);
1117 } 1126 }
1118 1127
1119 break; 1128 break;
… …
1122 { 1131 {
1123 auth_res_packet *p = (auth_res_packet *)pkt; 1132 auth_res_packet *p = (auth_res_packet *)pkt;
1124 1133
1125 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename); 1134 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename);
1126 1135
1127 if (p->chk_config ()) 1136 auth_mac local_mac;
1137 auth_hash (snd_auth, p->response.ecdh, local_mac);
1138
1139 if (memcmp (&p->response.mac, local_mac, sizeof local_mac))
1128 { 1140 {
1129 if (p->prot_minor != PROTOCOL_MINOR)
1130 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1131 conf->nodename, (const char *)rsi,
1132 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1133
1134 rsachallenge chg;
1135
1136 if (!rsa_cache.find (p->id, chg))
1137 {
1138 slog (L_ERR, _("%s(%s): unrequested auth response, ignoring."), 1141 slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."),
1139 conf->nodename, (const char *)rsi); 1142 conf->nodename, (const char *)rsi);
1140 break;
1141 } 1143 }
1142 else 1144 else if (!have_snd_auth)
1143 { 1145 {
1144 crypto_ctx *cctx = new crypto_ctx (chg, 0); 1146 memcpy (snd_ecdh_b, p->response.ecdh, sizeof snd_ecdh_b);
1145 1147
1146 if (!p->hmac_chk (cctx)) 1148 have_snd_auth = true;
1147 {
1148 slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n"
1149 "could be an attack, or just corruption or a synchronization error."),
1150 conf->nodename, (const char *)rsi);
1151 break;
1152 }
1153 else
1154 {
1155 rsaresponse h;
1156
1157 rsa_hash (p->id, chg, h);
1158
1159 if (!memcmp ((u8 *)&h, (u8 *)p->response, sizeof h))
1160 {
1161 prot_minor = p->prot_minor;
1162
1163 delete ictx; ictx = cctx;
1164
1165 iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
1166
1167 si = rsi;
1168 protocol = rsi.prot;
1169
1170 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
1171 conf->nodename, (const char *)rsi,
1172 is_direct ? "direct" : "forwarded",
1173 p->prot_major, p->prot_minor);
1174
1175 connection_established (); 1149 connection_established (rsi);
1176
1177 if (::conf.script_node_up)
1178 {
1179 run_script_cb *cb = new run_script_cb;
1180 cb->set<connection, &connection::script_node_up> (this);
1181 run_script_queued (cb, _("node-up command execution failed, continuing."));
1182 }
1183
1184 break;
1185 }
1186 else
1187 slog (L_ERR, _("%s(%s): sent and received challenge do not match."),
1188 conf->nodename, (const char *)rsi);
1189 }
1190
1191 delete cctx;
1192 }
1193 } 1150 }
1194 } 1151 }
1195
1196 send_reset (rsi);
1197 break; 1152 break;
1198 1153
1199 case vpn_packet::PT_DATA_COMPRESSED: 1154 case vpn_packet::PT_DATA_COMPRESSED:
1200#if !ENABLE_COMPRESSION 1155#if !ENABLE_COMPRESSION
1201 send_reset (rsi); 1156 send_reset (rsi);
… …
1274 if (p->id > 0 && p->id <= vpn->conns.size ()) 1229 if (p->id > 0 && p->id <= vpn->conns.size ())
1275 { 1230 {
1276 connection *c = vpn->conns[p->id - 1]; 1231 connection *c = vpn->conns[p->id - 1];
1277 conf->protocols = p->protocols; 1232 conf->protocols = p->protocols;
1278 1233
1279 slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s) [%d]", 1234 slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s,p%02x) [%d]",
1280 conf->nodename, vpn->conns[p->id - 1]->conf->nodename, c->ictx && c->octx); 1235 conf->nodename, vpn->conns[p->id - 1]->conf->nodename,
1236 p->protocols,
1237 c->ictx && c->octx);
1281 1238
1282 if (c->ictx && c->octx) 1239 if (c->ictx && c->octx)
1283 { 1240 {
1284 // send connect_info packets to both sides, in case one is 1241 // send connect_info packets to both sides, in case one is
1285 // behind a nat firewall (or both ;) 1242 // behind a nat firewall (or both ;)
… …
1308 1265
1309 c->conf->protocols = p->protocols; 1266 c->conf->protocols = p->protocols;
1310 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf)); 1267 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf));
1311 p->si.upgrade_protocol (protocol, c->conf); 1268 p->si.upgrade_protocol (protocol, c->conf);
1312 1269
1313 slog (L_TRACE, "%s >> PT_CONNECT_INFO(%s,%s) [%d]", 1270 slog (L_TRACE, "%s >> PT_CONNECT_INFO(%s,%s,protocols=%02x,protocol=%02x,upgradable=%02x) [%d]",
1271 conf->nodename,
1314 conf->nodename, vpn->conns[p->id - 1]->conf->nodename, 1272 vpn->conns[p->id - 1]->conf->nodename,
1273 (const char *)p->si,
1274 p->protocols,
1275 protocol,
1276 p->si.supported_protocols (c->conf),
1315 (const char *)p->si, !c->ictx && !c->octx); 1277 !c->ictx && !c->octx);
1316 1278
1317 const sockinfo &dsi = forward_si (p->si); 1279 const sockinfo &dsi = forward_si (p->si);
1318 1280
1319 if (dsi.valid ()) 1281 if (dsi.valid ())
1320 c->send_auth_request (dsi, true); 1282 c->send_auth_request (dsi, true);
1283 else
1284 slog (L_INFO, "connect info for %s received (%s), but still unable to contact.",
1285 vpn->conns[p->id - 1]->conf->nodename,
1286 (const char *)p->si);
1321 } 1287 }
1322 else 1288 else
1323 slog (L_WARN, 1289 slog (L_WARN,
1324 _("received authenticated connection request from unknown node #%d, config file mismatch?"), 1290 _("received authenticated connection request from unknown node #%d, config file mismatch?"),
1325 p->id); 1291 p->id);
… …
1334} 1300}
1335 1301
1336inline void 1302inline void
1337connection::keepalive_cb (ev::timer &w, int revents) 1303connection::keepalive_cb (ev::timer &w, int revents)
1338{ 1304{
1339 if (ev_now () >= last_activity + ::conf.keepalive + 15) 1305 ev_tstamp when = last_activity + ::conf.keepalive - ev::now ();
1306
1307 if (when >= 0)
1308 w.start (when);
1309 else if (when < -15)
1340 { 1310 {
1341 reset_connection (); 1311 reset_connection ();
1342 establish_connection (); 1312 establish_connection ();
1343 } 1313 }
1344 else if (ev_now () < last_activity + ::conf.keepalive)
1345 w.start (last_activity + ::conf.keepalive - ev::now ());
1346 else if (conf->connectmode != conf_node::C_ONDEMAND 1314 else if (conf->connectmode != conf_node::C_ONDEMAND
1347 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1315 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1348 { 1316 {
1317 w.start (3);
1349 send_ping (si); 1318 send_ping (si);
1350 w.start (3);
1351 } 1319 }
1352 else if (ev_now () < last_activity + ::conf.keepalive + 10) 1320 else if (when >= -10)
1353 // hold ondemand connections implicitly a few seconds longer 1321 // hold ondemand connections implicitly a few seconds longer
1354 // should delete octx, though, or something like that ;) 1322 // should delete octx, though, or something like that ;)
1355 w.start (last_activity + ::conf.keepalive + 10 - ev::now ()); 1323 w.start (when + 10);
1356 else 1324 else
1357 reset_connection (); 1325 reset_connection ();
1358} 1326}
1359 1327
1360void 1328void
1361connection::send_connect_request (int id) 1329connection::send_connect_request (int id)
1362{ 1330{
1363 connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols); 1331 connect_req_packet *p = new connect_req_packet (conf->id, id, THISNODE->protocols);
1364 1332
1365 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s)", 1333 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s,p%02x)",
1366 conf->nodename, vpn->conns[id - 1]->conf->nodename); 1334 conf->nodename, vpn->conns[id - 1]->conf->nodename,
1335 THISNODE->protocols);
1367 p->hmac_set (octx); 1336 p->hmac_set (octx);
1368 send_vpn_packet (p, si); 1337 send_vpn_packet (p, si);
1369 1338
1370 delete p; 1339 delete p;
1371} 1340}
… …
1455 establish_connection.set<connection, &connection::establish_connection_cb> (this); 1424 establish_connection.set<connection, &connection::establish_connection_cb> (this);
1456 1425
1457 last_establish_attempt = 0.; 1426 last_establish_attempt = 0.;
1458 octx = ictx = 0; 1427 octx = ictx = 0;
1459 1428
1460 if (!conf->protocols) // make sure some protocol is enabled
1461 conf->protocols = PROT_UDPv4;
1462
1463 connectmode = conf->connectmode; 1429 connectmode = conf->connectmode;
1464 1430
1465 // queue a dummy packet to force an initial connection attempt 1431 // queue a dummy packet to force an initial connection attempt
1466 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED) 1432 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED)
1467 vpn_queue.put (new net_packet); 1433 vpn_queue.put (new net_packet);

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