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Comparing gvpe/src/connection.C (file contents):
Revision 1.97 by root, Tue Dec 4 13:23:17 2012 UTC vs.
Revision 1.107 by root, Fri Sep 20 11:57:03 2013 UTC

1/* 1/*
2 connection.C -- manage a single connection 2 connection.C -- manage a single connection
3 Copyright (C) 2003-2008,2010,2011 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
… …
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) equire (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"
47#include "connection.h" 55#include "connection.h"
56#include "hkdf.h"
48 57
49#include "netcompat.h" 58#include "netcompat.h"
50 59
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) 60#define MAGIC "gvpe\xbd\xc6\xdb\x82" // 8 bytes of magic
61#define MAGIC "HUHN\xbd\xc6\xdb\x82" // 8 bytes of magic//D
57 62
58#define ULTRA_FAST 1 63#define ULTRA_FAST 1
59#define HLOG 15 64#define HLOG 15
60#include "lzf/lzf.h" 65#include "lzf/lzf.h"
61#include "lzf/lzf_c.c" 66#include "lzf/lzf_c.c"
… …
108struct crypto_ctx 113struct crypto_ctx
109{ 114{
110 EVP_CIPHER_CTX cctx; 115 EVP_CIPHER_CTX cctx;
111 HMAC_CTX hctx; 116 HMAC_CTX hctx;
112 117
113 crypto_ctx (const rsachallenge &challenge, int enc); 118 crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc);
114 ~crypto_ctx (); 119 ~crypto_ctx ();
115}; 120};
116 121
117crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc) 122crypto_ctx::crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc)
118{ 123{
124 ecdh_key s;
125
126 curve25519_combine (a, b, s);
127
128 {
129 u8 mac_key[MAC_KEYSIZE];
130 static const unsigned char mac_info[] = "gvpe mac key";
131
132 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
133 kdf.extract (auth1.rsa.mac_key, sizeof (auth1.rsa.mac_key));
134 kdf.extract (s, sizeof (s));
135 kdf.extract_done (HKDF_PRF_HASH ());
136 kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info));
137
138 HMAC_CTX_init (&hctx);
139 require101 (HMAC_Init_ex (&hctx, mac_key, MAC_KEYSIZE, MAC_DIGEST (), 0));
140 }
141
142 {
143 u8 cipher_key[CIPHER_KEYSIZE];
144 static const unsigned char cipher_info[] = "gvpe cipher key";
145
146 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
147 kdf.extract (auth1.rsa.cipher_key, sizeof (auth1.rsa.cipher_key));
148 kdf.extract (s, sizeof (s));
149 kdf.extract_done (HKDF_PRF_HASH ());
150 kdf.expand (cipher_key, sizeof (cipher_key), cipher_info, sizeof (cipher_info));
151
119 EVP_CIPHER_CTX_init (&cctx); 152 EVP_CIPHER_CTX_init (&cctx);
120 require (EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc)); 153 require (EVP_CipherInit_ex (&cctx, CIPHER (), 0, cipher_key, 0, enc));
121 HMAC_CTX_init (&hctx); 154 }
122 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
123} 155}
124 156
125crypto_ctx::~crypto_ctx () 157crypto_ctx::~crypto_ctx ()
126{ 158{
127 require (EVP_CIPHER_CTX_cleanup (&cctx)); 159 require (EVP_CIPHER_CTX_cleanup (&cctx));
128 HMAC_CTX_cleanup (&hctx); 160 HMAC_CTX_cleanup (&hctx);
129} 161}
130 162
163static inline void
164auth_encrypt (RSA *key, const auth_data &auth, auth_encr &encr)
165{
166 if (RSA_public_encrypt (sizeof (auth.rsa),
167 (unsigned char *)&auth.rsa, (unsigned char *)&encr.rsa,
168 key, RSA_PKCS1_OAEP_PADDING) < 0)
169 fatal ("RSA_public_encrypt error");
170
171 memcpy (&encr.ecdh, &auth.ecdh, sizeof (encr.ecdh));
172}
173
174static inline bool
175auth_decrypt (RSA *key, const auth_encr &encr, auth_data &auth)
176{
177 u8 rsa_decrypt[RSA_KEYLEN];
178
179 if (RSA_private_decrypt (sizeof (encr.rsa),
180 (const unsigned char *)&encr.rsa, (unsigned char *)rsa_decrypt,
181 key, RSA_PKCS1_OAEP_PADDING) != sizeof (auth.rsa))
182 return 0;
183
184 memcpy (&auth.rsa, rsa_decrypt, sizeof (auth.rsa));
185 memcpy (&auth.ecdh, &encr.ecdh, sizeof (auth.ecdh));
186
187 return 1;
188}
189
131static void 190static void
132rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h) 191auth_hash (const auth_data &auth, const ecdh_key &b, auth_mac &mac)
133{ 192{
134 EVP_MD_CTX ctx; 193 hkdf kdf (b, sizeof b, AUTH_DIGEST ()); // use response ecdh b as salt
135 194 kdf.extract (&auth.rsa, sizeof (auth.rsa));
136 EVP_MD_CTX_init (&ctx); 195 kdf.extract_done ();
137 require (EVP_DigestInit (&ctx, RSA_HASH)); 196 kdf.expand (mac, sizeof mac, auth.ecdh, sizeof (auth.ecdh)); // use challenge 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} 197}
143 198
144struct rsa_entry 199void
200connection::generate_auth_data ()
145{ 201{
146 tstamp expire; 202 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 { 203 {
159 if (!memcmp (&id, &i->id, sizeof id) && i->expire > ev_now ()) 204 // request data
160 { 205 rand_fill (snd_auth.rsa);
161 memcpy (&chg, &i->chg, sizeof chg); 206 curve25519_generate (snd_ecdh_a, snd_auth.ecdh);
162 207
163 erase (i); 208 // eventual response data
164 return true; 209 curve25519_generate (rcv_ecdh_a, rcv_ecdh_b);
165 }
166 } 210 }
167 211
168 if (!cleaner.is_active ()) 212 // 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; 213 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} 214}
213 215
214////////////////////////////////////////////////////////////////////////////// 216//////////////////////////////////////////////////////////////////////////////
215 217
216pkt_queue::pkt_queue (double max_ttl, int max_queue) 218pkt_queue::pkt_queue (double max_ttl, int max_queue)
… …
365 } 367 }
366} 368}
367 369
368///////////////////////////////////////////////////////////////////////////// 370/////////////////////////////////////////////////////////////////////////////
369 371
370unsigned char hmac_packet::hmac_digest[EVP_MAX_MD_SIZE];
371
372void 372void
373hmac_packet::hmac_gen (crypto_ctx *ctx) 373hmac_packet::hmac_gen (crypto_ctx *ctx, u8 *hmac_digest)
374{ 374{
375 unsigned int xlen;
376
377 HMAC_CTX *hctx = &ctx->hctx; 375 HMAC_CTX *hctx = &ctx->hctx;
378 376
379 HMAC_Init_ex (hctx, 0, 0, 0, 0); 377 require101 (HMAC_Init_ex (hctx, 0, 0, 0, 0));
380 HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), 378 require101 (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet)));
381 len - sizeof (hmac_packet)); 379 require101 (HMAC_Final (hctx, hmac_digest, 0));
382 HMAC_Final (hctx, (unsigned char *) &hmac_digest, &xlen);
383} 380}
384 381
385void 382void
386hmac_packet::hmac_set (crypto_ctx *ctx) 383hmac_packet::hmac_set (crypto_ctx *ctx)
387{ 384{
388 hmac_gen (ctx); 385 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
389 386 hmac_gen (ctx, hmac_digest);
390 memcpy (hmac, hmac_digest, HMACLENGTH); 387 memcpy (hmac, hmac_digest, HMACLENGTH);
391} 388}
392 389
393bool 390bool
394hmac_packet::hmac_chk (crypto_ctx *ctx) 391hmac_packet::hmac_chk (crypto_ctx *ctx)
395{ 392{
396 hmac_gen (ctx); 393 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
397 394 hmac_gen (ctx, hmac_digest);
398 return !memcmp (hmac, hmac_digest, HMACLENGTH); 395 return !memcmp (hmac, hmac_digest, HMACLENGTH);
399} 396}
400 397
401void 398void
402vpn_packet::set_hdr (ptype type_, unsigned int dst) 399vpn_packet::set_hdr (ptype type_, unsigned int dst)
… …
451 d[1] = cl; 448 d[1] = cl;
452 } 449 }
453 } 450 }
454#endif 451#endif
455 452
456 require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0)); 453 require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 1));
457 454
458 struct { 455 struct {
459#if RAND_SIZE 456#if RAND_SIZE
460 u8 rnd[RAND_SIZE]; 457 u8 rnd[RAND_SIZE];
461#endif 458#endif
462 u32 seqno; 459 u32 seqno;
463 } datahdr; 460 } datahdr;
464 461
465 datahdr.seqno = ntohl (seqno); 462 datahdr.seqno = ntohl (seqno);
466#if RAND_SIZE 463#if RAND_SIZE
467 RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE); 464 // NB: a constant (per session) random prefix
465 // is likely enough, but we don't take any chances.
466 conn->oiv.get (datahdr.rnd, RAND_SIZE);
468#endif 467#endif
469 468
470 require (EVP_EncryptUpdate (cctx, 469 require (EVP_EncryptUpdate (cctx,
471 (unsigned char *) data + outl, &outl2, 470 (unsigned char *) data + outl, &outl2,
472 (unsigned char *) &datahdr, DATAHDR)); 471 (unsigned char *) &datahdr, DATAHDR));
… …
494 int outl = 0, outl2; 493 int outl = 0, outl2;
495 tap_packet *p = new tap_packet; 494 tap_packet *p = new tap_packet;
496 u8 *d; 495 u8 *d;
497 u32 l = len - data_hdr_size (); 496 u32 l = len - data_hdr_size ();
498 497
499 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, 0)); 498 require (EVP_CipherInit_ex (cctx, 0, 0, 0, 0, 0));
500 499
501#if ENABLE_COMPRESSION 500#if ENABLE_COMPRESSION
502 u8 cdata[MAX_MTU]; 501 u8 cdata[MAX_MTU];
503 502
504 if (type == PT_DATA_COMPRESSED) 503 if (type == PT_DATA_COMPRESSED)
505 d = cdata; 504 d = cdata;
506 else 505 else
507#endif 506#endif
508 d = &(*p)[6 + 6 - DATAHDR]; 507 d = &(*p)[6 + 6] - DATAHDR;
509 508
510 /* this overwrites part of the src mac, but we fix that later */ 509 // we play do evil games with the struct layout atm.
510 // pending better solutions, we at least do some verification.
511 // this is fine, as we left ISO territory long ago.
512 require (DATAHDR <= 16);
513 require ((u8 *)(&p->len + 1) == &(*p)[0]);
514
515 // this can overwrite the len/dst/src fields
511 require (EVP_DecryptUpdate (cctx, 516 require (EVP_DecryptUpdate (cctx,
512 d, &outl2, 517 d, &outl2,
513 (unsigned char *)&data, len - data_hdr_size ())); 518 (unsigned char *)&data, len - data_hdr_size ()));
514 outl += outl2; 519 outl += outl2;
515 520
… …
546 } 551 }
547}; 552};
548 553
549struct config_packet : vpn_packet 554struct config_packet : vpn_packet
550{ 555{
551 // actually, hmaclen cannot be checked because the hmac 556 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; 557 u8 prot_major, prot_minor, randsize;
555 u8 flags, challengelen, features, pad3; 558 u8 flags, features, pad6, pad7, pad8;
556 u32 cipher_nid, digest_nid, hmac_nid; 559 u32 cipher_nid, mac_nid, auth_nid;
557 560
558 void setup (ptype type, int dst); 561 void setup (ptype type, int dst);
559 bool chk_config () const; 562 bool chk_config (const conf_node *conf, const sockinfo &rsi) const;
560 563
561 static u8 get_features () 564 static u8 get_features ()
562 { 565 {
563 u8 f = 0; 566 u8 f = 0;
564#if ENABLE_COMPRESSION 567#if ENABLE_COMPRESSION
… …
578config_packet::setup (ptype type, int dst) 581config_packet::setup (ptype type, int dst)
579{ 582{
580 prot_major = PROTOCOL_MAJOR; 583 prot_major = PROTOCOL_MAJOR;
581 prot_minor = PROTOCOL_MINOR; 584 prot_minor = PROTOCOL_MINOR;
582 randsize = RAND_SIZE; 585 randsize = RAND_SIZE;
583 hmaclen = HMACLENGTH;
584 flags = 0; 586 flags = 0;
585 challengelen = sizeof (rsachallenge);
586 features = get_features (); 587 features = get_features ();
587 588
589 strncpy ((char *)serial, conf.serial, sizeof (serial));
590
588 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER)); 591 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ()));
589 digest_nid = htonl (EVP_MD_type (RSA_HASH));
590 hmac_nid = htonl (EVP_MD_type (DIGEST)); 592 mac_nid = htonl (EVP_MD_type (MAC_DIGEST ()));
593 auth_nid = htonl (EVP_MD_type (AUTH_DIGEST ()));
591 594
592 len = sizeof (*this) - sizeof (net_packet); 595 len = sizeof (*this) - sizeof (net_packet);
593 set_hdr (type, dst); 596 set_hdr (type, dst);
594} 597}
595 598
596bool 599bool
597config_packet::chk_config () const 600config_packet::chk_config (const conf_node *conf, const sockinfo &rsi) const
598{ 601{
599 if (prot_major != PROTOCOL_MAJOR) 602 if (prot_major != PROTOCOL_MAJOR)
600 slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR); 603 slog (L_WARN, _("%s(%s): major version mismatch (remote %d <=> local %d)"),
604 conf->nodename, (const char *)rsi, prot_major, PROTOCOL_MAJOR);
601 else if (randsize != RAND_SIZE) 605 else if (randsize != RAND_SIZE)
602 slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE); 606 slog (L_WARN, _("%s(%s): rand size mismatch (remote %d <=> local %d)"),
603 else if (hmaclen != HMACLENGTH) 607 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))) 608 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)); 609 slog (L_WARN, _("%s(%s): cipher algo mismatch (remote %x <=> local %x)"),
609 else if (digest_nid != htonl (EVP_MD_type (RSA_HASH))) 610 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))) 611 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)); 612 slog (L_WARN, _("%s(%s): mac algo mismatch (remote %x <=> local %x)"),
613 conf->nodename, (const char *)rsi, ntohl (mac_nid), EVP_MD_type (MAC_DIGEST ()));
614 else if (auth_nid != htonl (EVP_MD_type (AUTH_DIGEST ())))
615 slog (L_WARN, _("%s(%s): auth algo mismatch (remote %x <=> local %x)"),
616 conf->nodename, (const char *)rsi, ntohl (auth_nid), EVP_MD_type (AUTH_DIGEST ()));
613 else 617 else
618 {
619 int cmp = memcmp (serial, ::conf.serial, sizeof (serial));
620
621 if (cmp > 0)
622 slog (L_WARN, _("%s(%s): remote serial newer than local serial - outdated config?"),
623 conf->nodename, (const char *)rsi);
624 else if (cmp == 0)
614 return true; 625 return true;
626 }
615 627
616 return false; 628 return false;
617} 629}
618 630
619struct auth_req_packet : config_packet 631struct auth_req_packet : config_packet // UNPROTECTED
620{ 632{
621 char magic[8]; 633 char magic[8];
622 u8 initiate; // false if this is just an automatic reply 634 u8 initiate; // false if this is just an automatic reply
623 u8 protocols; // supported protocols (will be patched on forward) 635 u8 protocols; // supported protocols (will be patched on forward)
624 u8 pad2, pad3; 636 u8 pad2, pad3;
625 rsaid id; 637 auth_encr encr;
626 rsaencrdata encr;
627 638
628 auth_req_packet (int dst, bool initiate_, u8 protocols_) 639 auth_req_packet (int dst, bool initiate_, u8 protocols_)
629 { 640 {
630 config_packet::setup (PT_AUTH_REQ, dst); 641 config_packet::setup (PT_AUTH_REQ, dst);
631 strncpy (magic, MAGIC_OLD, 8); 642 memcpy (magic, MAGIC, 8);
632 initiate = !!initiate_; 643 initiate = !!initiate_;
633 protocols = protocols_; 644 protocols = protocols_;
634 645
635 len = sizeof (*this) - sizeof (net_packet); 646 len = sizeof (*this) - sizeof (net_packet);
636 } 647 }
637}; 648};
638 649
639struct auth_res_packet : config_packet 650struct auth_res_packet : vpn_packet // UNPROTECTED
640{ 651{
641 rsaid id;
642 u8 pad1, pad2, pad3;
643 u8 response_len; // encrypted length
644 rsaresponse response; 652 auth_response response;
645 653
646 auth_res_packet (int dst) 654 auth_res_packet (int dst)
647 { 655 {
648 config_packet::setup (PT_AUTH_RES, dst); 656 set_hdr (PT_AUTH_RES, dst);
649 657
650 len = sizeof (*this) - sizeof (net_packet); 658 len = sizeof (*this) - sizeof (net_packet);
651 } 659 }
652}; 660};
653 661
… …
683}; 691};
684 692
685///////////////////////////////////////////////////////////////////////////// 693/////////////////////////////////////////////////////////////////////////////
686 694
687void 695void
688connection::connection_established () 696connection::connection_established (const sockinfo &rsi)
689{ 697{
690 slog (L_NOISE, _("%s: possible connection establish (ictx %d, octx %d)"), conf->nodename, !!ictx, !!octx); 698 if (!have_snd_auth || !have_rcv_auth)
699 return;
691 700
701 si = rsi;
702 protocol = rsi.prot;
703
704 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
705 conf->nodename, (const char *)rsi,
706 is_direct ? "direct" : "forwarded",
707 PROTOCOL_MAJOR, prot_minor);
708
709 if (::conf.script_node_up)
710 {
711 run_script_cb *cb = new run_script_cb;
712 cb->set<connection, &connection::script_node_up> (this);
713 run_script_queued (cb, _("node-up command execution failed, continuing."));
714 }
715
716 delete ictx; ictx = new crypto_ctx (rcv_auth, snd_auth, rcv_ecdh_a, rcv_auth.ecdh, 0);
717 iseqno.reset (ntohl (rcv_auth.rsa.seqno) & 0x7fffffff);
718
719 delete octx; octx = new crypto_ctx (snd_auth, rcv_auth, snd_ecdh_a, snd_ecdh_b , 1);
720 oseqno = ntohl (snd_auth.rsa.seqno) & 0x7fffffff;
721
722 oiv.reset ();
723
724 // make sure rekeying timeouts are slightly asymmetric
725 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0);
726 rekey.start (rekey_interval, rekey_interval);
727
728 keepalive.start (::conf.keepalive);
729
730 // send queued packets
692 if (ictx && octx) 731 if (ictx && octx)
693 { 732 {
694 // make sure rekeying timeouts are slightly asymmetric 733 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
698 keepalive.start (::conf.keepalive);
699
700 // send queued packets
701 if (ictx && octx)
702 { 734 {
703 while (tap_packet *p = (tap_packet *)data_queue.get ())
704 {
705 if (p->len) send_data_packet (p); 735 if (p->len) send_data_packet (p);
706 delete p; 736 delete p;
707 }
708
709 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
710 {
711 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
712 delete p;
713 }
714 } 737 }
715 738
739 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
740 {
741 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
742 delete p;
743 }
744 }
745
716 vpn->connection_established (this); 746 vpn->connection_established (this);
717 }
718 else
719 {
720 retry_cnt = 0;
721 establish_connection.start (5);
722 keepalive.stop ();
723 rekey.stop ();
724 }
725} 747}
726 748
727void 749void
728connection::reset_si () 750connection::reset_si ()
729{ 751{
… …
775 ping_packet *pkt = new ping_packet; 797 ping_packet *pkt = new ping_packet;
776 798
777 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING); 799 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING);
778 800
779 slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si); 801 slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si);
780
781 send_vpn_packet (pkt, si, IPTOS_LOWDELAY); 802 send_vpn_packet (pkt, si, IPTOS_LOWDELAY);
782 803
783 delete pkt; 804 delete pkt;
784} 805}
785 806
… …
800void 821void
801connection::send_auth_request (const sockinfo &si, bool initiate) 822connection::send_auth_request (const sockinfo &si, bool initiate)
802{ 823{
803 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols); 824 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols);
804 825
805 rsachallenge chg; 826 generate_auth_data ();
806 rsa_cache.gen (pkt->id, chg);
807 rsa_encrypt (conf->rsa_key, chg, pkt->encr); 827 auth_encrypt (conf->rsa_key, snd_auth, pkt->encr);
808 828
809 slog (L_TRACE, "%s << PT_AUTH_REQ [%s]", conf->nodename, (const char *)si); 829 slog (L_TRACE, "%s << PT_AUTH_REQ [%s]", conf->nodename, (const char *)si);
810
811 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly 830 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly
812 831
813 delete pkt; 832 delete pkt;
814} 833}
815 834
816void 835void
817connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg) 836connection::send_auth_response (const sockinfo &si)
818{ 837{
819 auth_res_packet *pkt = new auth_res_packet (conf->id); 838 auth_res_packet *pkt = new auth_res_packet (conf->id);
820 839
821 pkt->id = id; 840 memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof rcv_ecdh_b);
822 841 auth_hash (rcv_auth, rcv_ecdh_b, pkt->response.mac);
823 rsa_hash (id, chg, pkt->response);
824
825 pkt->hmac_set (octx);
826 842
827 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si); 843 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si);
828
829 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly 844 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly
830 845
831 delete pkt; 846 delete pkt;
832} 847}
833 848
… …
927 942
928 delete ictx; ictx = 0; 943 delete ictx; ictx = 0;
929 delete octx; octx = 0; 944 delete octx; octx = 0;
930 945
931 si.host = 0; 946 si.host = 0;
947
948 have_snd_auth = false;
949 have_rcv_auth = false;
950 auth_expire = 0.;
932 951
933 last_activity = 0.; 952 last_activity = 0.;
934 //last_si_change = 0.; 953 //last_si_change = 0.;
935 retry_cnt = 0; 954 retry_cnt = 0;
936 955
… …
1052 { 1071 {
1053 reset_connection (); 1072 reset_connection ();
1054 1073
1055 config_packet *p = (config_packet *) pkt; 1074 config_packet *p = (config_packet *) pkt;
1056 1075
1057 if (!p->chk_config ()) 1076 if (p->chk_config (conf, rsi) && connectmode == conf_node::C_ALWAYS)
1058 {
1059 slog (L_WARN, _("%s(%s): protocol mismatch, disabling node."),
1060 conf->nodename, (const char *)rsi);
1061 connectmode = conf_node::C_DISABLED;
1062 }
1063 else if (connectmode == conf_node::C_ALWAYS)
1064 establish_connection (); 1077 establish_connection ();
1065 } 1078 }
1066 break; 1079 break;
1067 1080
1068 case vpn_packet::PT_AUTH_REQ: 1081 case vpn_packet::PT_AUTH_REQ:
… …
1072 1085
1073 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s,p%02x,f%02x)", 1086 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s,p%02x,f%02x)",
1074 conf->nodename, p->initiate ? "initiate" : "reply", 1087 conf->nodename, p->initiate ? "initiate" : "reply",
1075 p->protocols, p->features); 1088 p->protocols, p->features);
1076 1089
1090 if (memcmp (p->magic, MAGIC, 8))
1091 {
1092 slog (L_WARN, _("%s(%s): protocol magic mismatch - stray packet?"),
1093 conf->nodename, (const char *)rsi);
1094 }
1077 if (p->chk_config () 1095 else if (p->chk_config (conf, rsi))
1078 && (!memcmp (p->magic, MAGIC_OLD, 8) || !memcmp (p->magic, MAGIC, 8)))
1079 { 1096 {
1080 if (p->prot_minor != PROTOCOL_MINOR) 1097 if (p->prot_minor != PROTOCOL_MINOR)
1081 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), 1098 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1082 conf->nodename, (const char *)rsi, 1099 conf->nodename, (const char *)rsi,
1083 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 1100 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1084 1101
1085 if (p->initiate) 1102 if (p->initiate)
1086 send_auth_request (rsi, false); 1103 send_auth_request (rsi, false);
1087 1104
1088 rsachallenge k; 1105 auth_data auth;
1089 1106
1090 if (!rsa_decrypt (::conf.rsa_key, p->encr, k)) 1107 if (!auth_decrypt (::conf.rsa_key, p->encr, auth))
1091 { 1108 {
1092 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"), 1109 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"),
1093 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0)); 1110 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0));
1094 break;
1095 } 1111 }
1096 else 1112 else
1097 { 1113 {
1098 delete octx; 1114 bool chg = !have_rcv_auth || memcmp (&rcv_auth, &auth, sizeof auth);
1099 1115
1100 octx = new crypto_ctx (k, 1); 1116 rcv_auth = auth;
1101 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; 1117 have_rcv_auth = true;
1102 1118
1119 send_auth_response (rsi);
1120
1121 if (chg)
1122 {
1103 conf->protocols = p->protocols; 1123 conf->protocols = p->protocols;
1104 features = p->features & config_packet::get_features (); 1124 features = p->features & config_packet::get_features ();
1105 1125
1106 send_auth_response (rsi, p->id, k);
1107
1108 connection_established (); 1126 connection_established (rsi);
1109
1110 break; 1127 }
1111 } 1128 }
1129
1130 break;
1112 } 1131 }
1113 else
1114 slog (L_WARN, _("%s(%s): protocol mismatch."),
1115 conf->nodename, (const char *)rsi);
1116 1132
1117 send_reset (rsi); 1133 send_reset (rsi);
1118 } 1134 }
1119 1135
1120 break; 1136 break;
… …
1123 { 1139 {
1124 auth_res_packet *p = (auth_res_packet *)pkt; 1140 auth_res_packet *p = (auth_res_packet *)pkt;
1125 1141
1126 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename); 1142 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename);
1127 1143
1128 if (p->chk_config ()) 1144 auth_mac local_mac;
1145 auth_hash (snd_auth, p->response.ecdh, local_mac);
1146
1147 if (memcmp (&p->response.mac, local_mac, sizeof local_mac))
1129 { 1148 {
1130 if (p->prot_minor != PROTOCOL_MINOR)
1131 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1132 conf->nodename, (const char *)rsi,
1133 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1134
1135 rsachallenge chg;
1136
1137 if (!rsa_cache.find (p->id, chg))
1138 {
1139 slog (L_ERR, _("%s(%s): unrequested auth response, ignoring."), 1149 slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."),
1140 conf->nodename, (const char *)rsi); 1150 conf->nodename, (const char *)rsi);
1141 break;
1142 } 1151 }
1143 else 1152 else if (!have_snd_auth)
1144 { 1153 {
1145 crypto_ctx *cctx = new crypto_ctx (chg, 0); 1154 memcpy (snd_ecdh_b, p->response.ecdh, sizeof snd_ecdh_b);
1146 1155
1147 if (!p->hmac_chk (cctx)) 1156 have_snd_auth = true;
1148 {
1149 slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n"
1150 "could be an attack, or just corruption or a synchronization error."),
1151 conf->nodename, (const char *)rsi);
1152 break;
1153 }
1154 else
1155 {
1156 rsaresponse h;
1157
1158 rsa_hash (p->id, chg, h);
1159
1160 if (!memcmp ((u8 *)&h, (u8 *)p->response, sizeof h))
1161 {
1162 prot_minor = p->prot_minor;
1163
1164 delete ictx; ictx = cctx;
1165
1166 iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
1167
1168 si = rsi;
1169 protocol = rsi.prot;
1170
1171 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
1172 conf->nodename, (const char *)rsi,
1173 is_direct ? "direct" : "forwarded",
1174 p->prot_major, p->prot_minor);
1175
1176 connection_established (); 1157 connection_established (rsi);
1177
1178 if (::conf.script_node_up)
1179 {
1180 run_script_cb *cb = new run_script_cb;
1181 cb->set<connection, &connection::script_node_up> (this);
1182 run_script_queued (cb, _("node-up command execution failed, continuing."));
1183 }
1184
1185 break;
1186 }
1187 else
1188 slog (L_ERR, _("%s(%s): sent and received challenge do not match."),
1189 conf->nodename, (const char *)rsi);
1190 }
1191
1192 delete cctx;
1193 }
1194 } 1158 }
1195 } 1159 }
1196
1197 send_reset (rsi);
1198 break; 1160 break;
1199 1161
1200 case vpn_packet::PT_DATA_COMPRESSED: 1162 case vpn_packet::PT_DATA_COMPRESSED:
1201#if !ENABLE_COMPRESSION 1163#if !ENABLE_COMPRESSION
1202 send_reset (rsi); 1164 send_reset (rsi);

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