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Comparing gvpe/src/connection.C (file contents):
Revision 1.88 by root, Thu Dec 2 07:15:14 2010 UTC vs.
Revision 1.113 by root, Thu Jan 29 00:21:39 2015 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
… …
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"
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
57 61
58#define ULTRA_FAST 1 62#define ULTRA_FAST 1
59#define HLOG 15 63#define HLOG 15
60#include "lzf/lzf.h" 64#include "lzf/lzf.h"
61#include "lzf/lzf_c.c" 65#include "lzf/lzf_c.c"
… …
64////////////////////////////////////////////////////////////////////////////// 68//////////////////////////////////////////////////////////////////////////////
65 69
66static std::queue< std::pair<run_script_cb *, const char *> > rs_queue; 70static std::queue< std::pair<run_script_cb *, const char *> > rs_queue;
67static ev::child rs_child_ev; 71static ev::child rs_child_ev;
68 72
73namespace
74{
69void // c++ requires external linkage here, apparently :( 75 void // c++ requires external linkage here, apparently :(
70rs_child_cb (ev::child &w, int revents) 76 rs_child_cb (ev::child &w, int revents)
71{ 77 {
72 w.stop (); 78 w.stop ();
73 79
74 if (rs_queue.empty ()) 80 if (rs_queue.empty ())
75 return; 81 return;
76 82
77 pid_t pid = run_script (*rs_queue.front ().first, false); 83 pid_t pid = run_script (*rs_queue.front ().first, false);
78 if (pid) 84 if (pid)
79 { 85 {
80 w.set (pid); 86 w.set (pid);
81 w.start (); 87 w.start ();
82 } 88 }
83 else 89 else
84 slog (L_WARN, rs_queue.front ().second); 90 slog (L_WARN, rs_queue.front ().second);
85 91
86 delete rs_queue.front ().first; 92 delete rs_queue.front ().first;
87 rs_queue.pop (); 93 rs_queue.pop ();
88} 94 }
95};
89 96
90// despite the fancy name, this is quite a hack 97// despite the fancy name, this is quite a hack
91static void 98static void
92run_script_queued (run_script_cb *cb, const char *warnmsg) 99run_script_queued (run_script_cb *cb, const char *warnmsg)
93{ 100{
… …
105struct crypto_ctx 112struct crypto_ctx
106{ 113{
107 EVP_CIPHER_CTX cctx; 114 EVP_CIPHER_CTX cctx;
108 HMAC_CTX hctx; 115 HMAC_CTX hctx;
109 116
110 crypto_ctx (const rsachallenge &challenge, int enc); 117 crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc);
111 ~crypto_ctx (); 118 ~crypto_ctx ();
112}; 119};
113 120
114crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc) 121crypto_ctx::crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc)
115{ 122{
123 ecdh_key s;
124
125 curve25519_combine (a, b, s);
126
127 {
128 u8 mac_key[MAC_KEYSIZE];
129 static const unsigned char mac_info[] = "gvpe mac key";
130
131 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
132 kdf.extract (auth1.rsa.mac_key, sizeof (auth1.rsa.mac_key));
133 kdf.extract (s, sizeof (s));
134 kdf.extract_done (HKDF_PRF_HASH ());
135 kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info));
136
137 HMAC_CTX_init (&hctx);
138 require101 (HMAC_Init_ex (&hctx, mac_key, MAC_KEYSIZE, MAC_DIGEST (), 0));
139 }
140
141 {
142 u8 cipher_key[CIPHER_KEYSIZE];
143 static const unsigned char cipher_info[] = "gvpe cipher key";
144
145 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
146 kdf.extract (auth1.rsa.cipher_key, sizeof (auth1.rsa.cipher_key));
147 kdf.extract (s, sizeof (s));
148 kdf.extract_done (HKDF_PRF_HASH ());
149 kdf.expand (cipher_key, sizeof (cipher_key), cipher_info, sizeof (cipher_info));
150
116 EVP_CIPHER_CTX_init (&cctx); 151 EVP_CIPHER_CTX_init (&cctx);
117 require (EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc)); 152 require (EVP_CipherInit_ex (&cctx, CIPHER (), 0, cipher_key, 0, enc));
118 HMAC_CTX_init (&hctx); 153 }
119 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
120} 154}
121 155
122crypto_ctx::~crypto_ctx () 156crypto_ctx::~crypto_ctx ()
123{ 157{
124 require (EVP_CIPHER_CTX_cleanup (&cctx)); 158 require (EVP_CIPHER_CTX_cleanup (&cctx));
125 HMAC_CTX_cleanup (&hctx); 159 HMAC_CTX_cleanup (&hctx);
126} 160}
127 161
162static inline void
163auth_encrypt (RSA *key, const auth_data &auth, auth_encr &encr)
164{
165 if (RSA_public_encrypt (sizeof (auth.rsa),
166 (unsigned char *)&auth.rsa, (unsigned char *)&encr.rsa,
167 key, RSA_PKCS1_OAEP_PADDING) < 0)
168 fatal ("RSA_public_encrypt error");
169
170 memcpy (&encr.ecdh, &auth.ecdh, sizeof (encr.ecdh));
171}
172
173static inline bool
174auth_decrypt (RSA *key, const auth_encr &encr, auth_data &auth)
175{
176 u8 rsa_decrypt[RSA_KEYLEN];
177
178 if (RSA_private_decrypt (sizeof (encr.rsa),
179 (const unsigned char *)&encr.rsa, (unsigned char *)rsa_decrypt,
180 key, RSA_PKCS1_OAEP_PADDING) != sizeof (auth.rsa))
181 return 0;
182
183 memcpy (&auth.rsa, rsa_decrypt, sizeof (auth.rsa));
184 memcpy (&auth.ecdh, &encr.ecdh, sizeof (auth.ecdh));
185
186 return 1;
187}
188
128static void 189static void
129rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h) 190auth_hash (const auth_data &auth, const ecdh_key &b, auth_mac &mac)
130{ 191{
131 EVP_MD_CTX ctx; 192 hkdf kdf (b, sizeof b, AUTH_DIGEST ()); // use response ecdh b as salt
132 193 kdf.extract (&auth.rsa, sizeof (auth.rsa));
133 EVP_MD_CTX_init (&ctx); 194 kdf.extract_done ();
134 require (EVP_DigestInit (&ctx, RSA_HASH)); 195 kdf.expand (mac, sizeof mac, auth.ecdh, sizeof (auth.ecdh)); // use challenge ecdh b as info
135 require (EVP_DigestUpdate(&ctx, &chg, sizeof chg));
136 require (EVP_DigestUpdate(&ctx, &id, sizeof id));
137 require (EVP_DigestFinal (&ctx, (unsigned char *)&h, 0));
138 EVP_MD_CTX_cleanup (&ctx);
139} 196}
140 197
141struct rsa_entry 198void
199connection::generate_auth_data ()
142{ 200{
143 tstamp expire; 201 if (auth_expire < ev_now ())
144 rsaid id;
145 rsachallenge chg;
146};
147
148struct rsa_cache : list<rsa_entry>
149{
150 inline void cleaner_cb (ev::timer &w, int revents); ev::timer cleaner;
151
152 bool find (const rsaid &id, rsachallenge &chg)
153 {
154 for (iterator i = begin (); i != end (); ++i)
155 { 202 {
156 if (!memcmp (&id, &i->id, sizeof id) && i->expire > ev_now ()) 203 // request data
157 { 204 rand_fill (snd_auth.rsa);
158 memcpy (&chg, &i->chg, sizeof chg); 205 curve25519_generate (snd_ecdh_a, snd_auth.ecdh);
159 206
160 erase (i); 207 // eventual response data
161 return true; 208 curve25519_generate (rcv_ecdh_a, rcv_ecdh_b);
162 }
163 } 209 }
164 210
165 if (!cleaner.is_active ()) 211 // every use prolongs the expiry
166 cleaner.again ();
167
168 return false;
169 }
170
171 void gen (rsaid &id, rsachallenge &chg)
172 {
173 rsa_entry e;
174
175 RAND_bytes ((unsigned char *)&id, sizeof id);
176 RAND_bytes ((unsigned char *)&chg, sizeof chg);
177
178 e.expire = ev_now () + RSA_TTL; 212 auth_expire = ev_now () + AUTH_TTL;
179 e.id = id;
180 memcpy (&e.chg, &chg, sizeof chg);
181
182 push_back (e);
183
184 if (!cleaner.is_active ())
185 cleaner.again ();
186 }
187
188 rsa_cache ()
189 {
190 cleaner.set<rsa_cache, &rsa_cache::cleaner_cb> (this);
191 cleaner.set (RSA_TTL, RSA_TTL);
192 }
193
194} rsa_cache;
195
196void rsa_cache::cleaner_cb (ev::timer &w, int revents)
197{
198 if (empty ())
199 w.stop ();
200 else
201 {
202 for (iterator i = begin (); i != end (); )
203 if (i->expire <= ev_now ())
204 i = erase (i);
205 else
206 ++i;
207 }
208} 213}
209 214
210////////////////////////////////////////////////////////////////////////////// 215//////////////////////////////////////////////////////////////////////////////
211 216
212pkt_queue::pkt_queue (double max_ttl, int max_queue) 217pkt_queue::pkt_queue (double max_ttl, int max_queue)
… …
226 delete p; 231 delete p;
227 232
228 delete [] queue; 233 delete [] queue;
229} 234}
230 235
236void
231void pkt_queue::expire_cb (ev::timer &w, int revents) 237pkt_queue::expire_cb (ev::timer &w, int revents)
232{ 238{
233 ev_tstamp expire = ev_now () - max_ttl; 239 ev_tstamp expire = ev_now () - max_ttl;
234 240
235 for (;;) 241 for (;;)
236 { 242 {
… …
247 253
248 delete get (); 254 delete get ();
249 } 255 }
250} 256}
251 257
258void
252void pkt_queue::put (net_packet *p) 259pkt_queue::put (net_packet *p)
253{ 260{
254 ev_tstamp now = ev_now (); 261 ev_tstamp now = ev_now ();
255 262
256 // start expiry timer 263 // start expiry timer
257 if (empty ()) 264 if (empty ())
… …
266 queue[i].tstamp = now; 273 queue[i].tstamp = now;
267 274
268 i = ni; 275 i = ni;
269} 276}
270 277
271net_packet *pkt_queue::get () 278net_packet *
279pkt_queue::get ()
272{ 280{
273 if (empty ()) 281 if (empty ())
274 return 0; 282 return 0;
275 283
276 net_packet *p = queue[j].pkt; 284 net_packet *p = queue[j].pkt;
… …
300 308
301 bool can (const sockinfo &si) { return can((u32)si.host); } 309 bool can (const sockinfo &si) { return can((u32)si.host); }
302 bool can (u32 host); 310 bool can (u32 host);
303}; 311};
304 312
305net_rate_limiter auth_rate_limiter, reset_rate_limiter; 313static net_rate_limiter auth_rate_limiter, reset_rate_limiter;
306 314
315bool
307bool net_rate_limiter::can (u32 host) 316net_rate_limiter::can (u32 host)
308{ 317{
309 iterator i; 318 iterator i;
310 319
311 for (i = begin (); i != end (); ) 320 for (i = begin (); i != end (); )
312 if (i->host == host) 321 if (i->host == host)
… …
357 } 366 }
358} 367}
359 368
360///////////////////////////////////////////////////////////////////////////// 369/////////////////////////////////////////////////////////////////////////////
361 370
362unsigned char hmac_packet::hmac_digest[EVP_MAX_MD_SIZE]; 371void
363
364void hmac_packet::hmac_gen (crypto_ctx *ctx) 372hmac_packet::hmac_gen (crypto_ctx *ctx, u8 *hmac_digest)
365{ 373{
366 unsigned int xlen;
367
368 HMAC_CTX *hctx = &ctx->hctx; 374 HMAC_CTX *hctx = &ctx->hctx;
369 375
370 HMAC_Init_ex (hctx, 0, 0, 0, 0); 376 require101 (HMAC_Init_ex (hctx, 0, 0, 0, 0));
371 HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), 377 require101 (HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet)));
372 len - sizeof (hmac_packet)); 378 require101 (HMAC_Final (hctx, hmac_digest, 0));
373 HMAC_Final (hctx, (unsigned char *) &hmac_digest, &xlen);
374} 379}
375 380
376void 381void
377hmac_packet::hmac_set (crypto_ctx *ctx) 382hmac_packet::hmac_set (crypto_ctx *ctx)
378{ 383{
379 hmac_gen (ctx); 384 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
380 385 hmac_gen (ctx, hmac_digest);
381 memcpy (hmac, hmac_digest, HMACLENGTH); 386 memcpy (hmac, hmac_digest, HMACLENGTH);
382} 387}
383 388
384bool 389bool
385hmac_packet::hmac_chk (crypto_ctx *ctx) 390hmac_packet::hmac_chk (crypto_ctx *ctx)
386{ 391{
387 hmac_gen (ctx); 392 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
388 393 hmac_gen (ctx, hmac_digest);
389 return !memcmp (hmac, hmac_digest, HMACLENGTH); 394 return slow_memeq (hmac, hmac_digest, HMACLENGTH);
390} 395}
391 396
397void
392void vpn_packet::set_hdr (ptype type_, unsigned int dst) 398vpn_packet::set_hdr (ptype type_, unsigned int dst)
393{ 399{
394 type = type_; 400 type = type_;
395 401
396 int src = THISNODE->id; 402 int src = THISNODE->id;
397 403
… …
399 srcdst = ((src >> 8) << 4) | (dst >> 8); 405 srcdst = ((src >> 8) << 4) | (dst >> 8);
400 dst1 = dst; 406 dst1 = dst;
401} 407}
402 408
403#define MAXVPNDATA (MAX_MTU - 6 - 6) 409#define MAXVPNDATA (MAX_MTU - 6 - 6)
404#define DATAHDR (sizeof (u32) + RAND_SIZE)
405 410
406struct vpndata_packet : vpn_packet 411struct vpndata_packet : vpn_packet
412{
413 u32 ctr; // seqno
414 u8 data[MAXVPNDATA];
415
416 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
417 tap_packet *unpack (connection *conn, u32 &seqno);
418
419private:
420 const u32 data_hdr_size () const
407 { 421 {
408 u8 data[MAXVPNDATA + DATAHDR]; // seqno 422 // the distance from beginning of packet to data member
409 423 return data - at (0);
410 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
411 tap_packet *unpack (connection *conn, u32 &seqno);
412private:
413
414 const u32 data_hdr_size () const
415 {
416 return sizeof (vpndata_packet) - sizeof (net_packet) - MAXVPNDATA - DATAHDR;
417 }
418 }; 424 }
425};
426
427// expands packet counter (unlike seqno, in network byte order) to counter mode IV
428static unsigned char *
429expand_iv (u32 ctr)
430{
431 static u32 iv[IV_SIZE (CIPHER) / 4];
432
433 require (sizeof (iv) == 4 * 4);
434 require (IV_SIZE (CIPHER) % 4 == 0);
435
436 iv[0] =
437 iv[1] =
438 iv[2] = ctr;
439
440 // I would reuse ctr here to to avoid potential endianness issues,
441 // but it seems openssl wraps around. While this would be still ok,
442 // and I don't even know if its true, let's play safe and initialise
443 // to 0.
444 iv[3] = 0;
445
446 return (unsigned char *)iv;
447}
419 448
420void 449void
421vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno) 450vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno)
422{ 451{
423 EVP_CIPHER_CTX *cctx = &conn->octx->cctx; 452 EVP_CIPHER_CTX *cctx = &conn->octx->cctx;
… …
441 d[1] = cl; 470 d[1] = cl;
442 } 471 }
443 } 472 }
444#endif 473#endif
445 474
475 ctr = htonl (seqno);
476
446 require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0)); 477 require (EVP_EncryptInit_ex (cctx, 0, 0, 0, expand_iv (ctr)));
447
448 struct {
449#if RAND_SIZE
450 u8 rnd[RAND_SIZE];
451#endif
452 u32 seqno;
453 } datahdr;
454
455 datahdr.seqno = ntohl (seqno);
456#if RAND_SIZE
457 RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE);
458#endif
459 478
460 require (EVP_EncryptUpdate (cctx, 479 require (EVP_EncryptUpdate (cctx,
461 (unsigned char *) data + outl, &outl2, 480 (unsigned char *)data + outl, &outl2,
462 (unsigned char *) &datahdr, DATAHDR)); 481 (unsigned char *)d, l));
463 outl += outl2; 482 outl += outl2;
464 483
465 require (EVP_EncryptUpdate (cctx, 484 // it seems this is a nop for us, but we do it anyways
466 (unsigned char *) data + outl, &outl2, 485 require (EVP_EncryptFinal_ex (cctx, (unsigned char *)data + outl, &outl2));
467 (unsigned char *) d, l));
468 outl += outl2; 486 outl += outl2;
469 487
470 require (EVP_EncryptFinal_ex (cctx, (unsigned char *) data + outl, &outl2));
471 outl += outl2;
472
473 len = outl + data_hdr_size (); 488 len = data_hdr_size () + outl;
474 489
475 set_hdr (type, dst); 490 set_hdr (type, dst);
476 491
477 hmac_set (conn->octx); 492 hmac_set (conn->octx);
478} 493}
… …
482{ 497{
483 EVP_CIPHER_CTX *cctx = &conn->ictx->cctx; 498 EVP_CIPHER_CTX *cctx = &conn->ictx->cctx;
484 int outl = 0, outl2; 499 int outl = 0, outl2;
485 tap_packet *p = new tap_packet; 500 tap_packet *p = new tap_packet;
486 u8 *d; 501 u8 *d;
487 u32 l = len - data_hdr_size ();
488 502
503 seqno = ntohl (ctr);
504
489 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, 0)); 505 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, expand_iv (ctr)));
490 506
491#if ENABLE_COMPRESSION 507#if ENABLE_COMPRESSION
492 u8 cdata[MAX_MTU]; 508 u8 cdata[MAX_MTU];
493 509
494 if (type == PT_DATA_COMPRESSED) 510 if (type == PT_DATA_COMPRESSED)
495 d = cdata; 511 d = cdata;
496 else 512 else
497#endif 513#endif
498 d = &(*p)[6 + 6 - DATAHDR]; 514 d = &(*p)[6 + 6];
499 515
500 /* this overwrites part of the src mac, but we fix that later */ 516 // this can overwrite the len/dst/src fields
501 require (EVP_DecryptUpdate (cctx, 517 require (EVP_DecryptUpdate (cctx,
502 d, &outl2, 518 d, &outl2,
503 (unsigned char *)&data, len - data_hdr_size ())); 519 (unsigned char *)&data, len - data_hdr_size ()));
504 outl += outl2; 520 outl += outl2;
505 521
522 // it seems this is a nop for us, but we do it anyways
506 require (EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2)); 523 require (EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2));
507 outl += outl2; 524 outl += outl2;
508 525
509 seqno = ntohl (*(u32 *)(d + RAND_SIZE));
510
511 id2mac (dst () ? dst() : THISNODE->id, p->dst); 526 id2mac (dst () ? dst() : THISNODE->id, p->dst);
512 id2mac (src (), p->src); 527 id2mac (src (), p->src);
513 528
514#if ENABLE_COMPRESSION 529#if ENABLE_COMPRESSION
515 if (type == PT_DATA_COMPRESSED) 530 if (type == PT_DATA_COMPRESSED)
516 { 531 {
517 u32 cl = (d[DATAHDR] << 8) | d[DATAHDR + 1]; 532 u32 cl = (d[0] << 8) | d[1];
518 533
519 p->len = lzf_decompress (d + DATAHDR + 2, cl < MAX_MTU ? cl : 0, 534 p->len = lzf_decompress (d + 2, cl < MAX_MTU - 2 ? cl : 0,
520 &(*p)[6 + 6], MAX_MTU) 535 &(*p)[6 + 6], MAX_MTU)
521 + 6 + 6; 536 + 6 + 6;
522 } 537 }
523 else 538 else
524 p->len = outl + (6 + 6 - DATAHDR); 539 p->len = outl + (6 + 6);
525#endif 540#endif
526 541
527 return p; 542 return p;
528} 543}
529 544
… …
536 } 551 }
537}; 552};
538 553
539struct config_packet : vpn_packet 554struct config_packet : vpn_packet
540{ 555{
541 // actually, hmaclen cannot be checked because the hmac 556 u8 serial[SERIAL_SIZE];
542 // field comes before this data, so peers with other
543 // hmacs simply will not work.
544 u8 prot_major, prot_minor, randsize, hmaclen; 557 u8 prot_major, prot_minor, randsize;
545 u8 flags, challengelen, features, pad3; 558 u8 flags, features, pad6, pad7, pad8;
546 u32 cipher_nid, digest_nid, hmac_nid; 559 u32 cipher_nid, mac_nid, auth_nid;
547 560
548 void setup (ptype type, int dst); 561 void setup (ptype type, int dst);
549 bool chk_config () const; 562 bool chk_config (const conf_node *conf, const sockinfo &rsi) const;
550 563
551 static u8 get_features () 564 static u8 get_features ()
552 { 565 {
553 u8 f = 0; 566 u8 f = 0;
554#if ENABLE_COMPRESSION 567#if ENABLE_COMPRESSION
… …
562#endif 575#endif
563 return f; 576 return f;
564 } 577 }
565}; 578};
566 579
580void
567void config_packet::setup (ptype type, int dst) 581config_packet::setup (ptype type, int dst)
568{ 582{
569 prot_major = PROTOCOL_MAJOR; 583 prot_major = PROTOCOL_MAJOR;
570 prot_minor = PROTOCOL_MINOR; 584 prot_minor = PROTOCOL_MINOR;
571 randsize = RAND_SIZE;
572 hmaclen = HMACLENGTH;
573 flags = 0; 585 flags = 0;
574 challengelen = sizeof (rsachallenge);
575 features = get_features (); 586 features = get_features ();
576 587
588 strncpy ((char *)serial, conf.serial, sizeof (serial));
589
577 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER)); 590 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ()));
578 digest_nid = htonl (EVP_MD_type (RSA_HASH));
579 hmac_nid = htonl (EVP_MD_type (DIGEST)); 591 mac_nid = htonl (EVP_MD_type (MAC_DIGEST ()));
592 auth_nid = htonl (EVP_MD_type (AUTH_DIGEST ()));
580 593
581 len = sizeof (*this) - sizeof (net_packet); 594 len = sizeof (*this) - sizeof (net_packet);
582 set_hdr (type, dst); 595 set_hdr (type, dst);
583} 596}
584 597
585bool config_packet::chk_config () const 598bool
599config_packet::chk_config (const conf_node *conf, const sockinfo &rsi) const
586{ 600{
587 if (prot_major != PROTOCOL_MAJOR) 601 if (prot_major != PROTOCOL_MAJOR)
588 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)"),
589 else if (randsize != RAND_SIZE) 603 conf->nodename, (const char *)rsi, prot_major, PROTOCOL_MAJOR);
590 slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE);
591 else if (hmaclen != HMACLENGTH)
592 slog (L_WARN, _("hmac length mismatch (remote %d <=> local %d)"), hmaclen, HMACLENGTH);
593 else if (challengelen != sizeof (rsachallenge))
594 slog (L_WARN, _("challenge length mismatch (remote %d <=> local %d)"), challengelen, sizeof (rsachallenge));
595 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER))) 604 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER ())))
596 slog (L_WARN, _("cipher mismatch (remote %x <=> local %x)"), ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER)); 605 slog (L_WARN, _("%s(%s): cipher algo mismatch (remote %x <=> local %x)"),
597 else if (digest_nid != htonl (EVP_MD_type (RSA_HASH))) 606 conf->nodename, (const char *)rsi, ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER ()));
598 slog (L_WARN, _("digest mismatch (remote %x <=> local %x)"), ntohl (digest_nid), EVP_MD_type (RSA_HASH));
599 else if (hmac_nid != htonl (EVP_MD_type (DIGEST))) 607 else if (mac_nid != htonl (EVP_MD_type (MAC_DIGEST ())))
600 slog (L_WARN, _("hmac mismatch (remote %x <=> local %x)"), ntohl (hmac_nid), EVP_MD_type (DIGEST)); 608 slog (L_WARN, _("%s(%s): mac algo mismatch (remote %x <=> local %x)"),
609 conf->nodename, (const char *)rsi, ntohl (mac_nid), EVP_MD_type (MAC_DIGEST ()));
610 else if (auth_nid != htonl (EVP_MD_type (AUTH_DIGEST ())))
611 slog (L_WARN, _("%s(%s): auth algo mismatch (remote %x <=> local %x)"),
612 conf->nodename, (const char *)rsi, ntohl (auth_nid), EVP_MD_type (AUTH_DIGEST ()));
601 else 613 else
614 {
615 int cmp = memcmp (serial, ::conf.serial, sizeof (serial));
616
617 if (cmp > 0)
618 slog (L_WARN, _("%s(%s): remote serial newer than local serial - outdated config?"),
619 conf->nodename, (const char *)rsi);
620 else if (cmp == 0)
602 return true; 621 return true;
622 }
603 623
604 return false; 624 return false;
605} 625}
606 626
607struct auth_req_packet : config_packet 627struct auth_req_packet : config_packet // UNPROTECTED
608{ 628{
609 char magic[8]; 629 char magic[8];
610 u8 initiate; // false if this is just an automatic reply 630 u8 initiate; // false if this is just an automatic reply
611 u8 protocols; // supported protocols (will be patched on forward) 631 u8 protocols; // supported protocols (will be patched on forward)
612 u8 pad2, pad3; 632 u8 pad2, pad3;
613 rsaid id; 633 auth_encr encr;
614 rsaencrdata encr;
615 634
616 auth_req_packet (int dst, bool initiate_, u8 protocols_) 635 auth_req_packet (int dst, bool initiate_, u8 protocols_)
617 { 636 {
618 config_packet::setup (PT_AUTH_REQ, dst); 637 config_packet::setup (PT_AUTH_REQ, dst);
619 strncpy (magic, MAGIC_OLD, 8); 638 memcpy (magic, MAGIC, 8);
620 initiate = !!initiate_; 639 initiate = !!initiate_;
621 protocols = protocols_; 640 protocols = protocols_;
622 641
623 len = sizeof (*this) - sizeof (net_packet); 642 len = sizeof (*this) - sizeof (net_packet);
624 } 643 }
625}; 644};
626 645
627struct auth_res_packet : config_packet 646struct auth_res_packet : vpn_packet // UNPROTECTED
628{ 647{
629 rsaid id;
630 u8 pad1, pad2, pad3;
631 u8 response_len; // encrypted length
632 rsaresponse response; 648 auth_response response;
633 649
634 auth_res_packet (int dst) 650 auth_res_packet (int dst)
635 { 651 {
636 config_packet::setup (PT_AUTH_RES, dst); 652 set_hdr (PT_AUTH_RES, dst);
637 653
638 len = sizeof (*this) - sizeof (net_packet); 654 len = sizeof (*this) - sizeof (net_packet);
639 } 655 }
640}; 656};
641 657
… …
671}; 687};
672 688
673///////////////////////////////////////////////////////////////////////////// 689/////////////////////////////////////////////////////////////////////////////
674 690
675void 691void
676connection::connection_established () 692connection::connection_established (const sockinfo &rsi)
677{ 693{
678 slog (L_NOISE, _("%s: possible connection establish (ictx %d, octx %d)"), conf->nodename, !!ictx, !!octx); 694 if (!have_snd_auth || !have_rcv_auth)
695 return;
679 696
680 if (ictx && octx) 697 si = rsi;
698 protocol = rsi.prot;
699
700 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
701 conf->nodename, (const char *)rsi,
702 vpn->can_direct (THISNODE, conf) ? "direct" : "forwarded",
703 PROTOCOL_MAJOR, prot_minor);
704
705 if (::conf.script_node_up)
706 {
707 run_script_cb *cb = new run_script_cb;
708 cb->set<connection, &connection::script_node_up> (this);
709 run_script_queued (cb, _("node-up command execution failed, continuing."));
681 { 710 }
711
712 delete ictx; ictx = new crypto_ctx (rcv_auth, snd_auth, rcv_ecdh_a, rcv_auth.ecdh, 0);
713 iseqno.reset (ntohl (rcv_auth.rsa.seqno) & 0x7fffffff);
714
715 delete octx; octx = new crypto_ctx (snd_auth, rcv_auth, snd_ecdh_a, snd_ecdh_b , 1);
716 oseqno = ntohl (snd_auth.rsa.seqno) & 0x7fffffff;
717
682 // make sure rekeying timeouts are slightly asymmetric 718 // make sure rekeying timeouts are slightly asymmetric
683 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0); 719 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0);
684 rekey.start (rekey_interval, rekey_interval); 720 rekey.start (rekey_interval, rekey_interval);
721
722 hmac_error = 0.;
723
685 keepalive.start (::conf.keepalive); 724 keepalive.start (::conf.keepalive);
686 725
687 // send queued packets 726 // send queued packets
688 if (ictx && octx)
689 {
690 while (tap_packet *p = (tap_packet *)data_queue.get ()) 727 while (tap_packet *p = (tap_packet *)data_queue.get ())
691 { 728 {
692 if (p->len) send_data_packet (p); 729 if (p->len) send_data_packet (p);
693 delete p; 730 delete p;
694 } 731 }
695 732
696 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) 733 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
697 { 734 {
698 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY); 735 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
699 delete p; 736 delete p;
700 } 737 }
701 }
702 738
703 vpn->connection_established (this); 739 vpn->connection_established (this);
704 }
705 else
706 {
707 retry_cnt = 0;
708 establish_connection.start (5);
709 keepalive.stop ();
710 rekey.stop ();
711 }
712} 740}
713 741
714void 742void
715connection::reset_si () 743connection::reset_si ()
716{ 744{
… …
721 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename); 749 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename);
722 protocol = 0; 750 protocol = 0;
723 } 751 }
724 752
725 si.set (conf, protocol); 753 si.set (conf, protocol);
726
727 is_direct = si.valid ();
728} 754}
729 755
730// ensure sockinfo is valid, forward if necessary 756// ensure sockinfo is valid, forward if necessary
731const sockinfo & 757const sockinfo &
732connection::forward_si (const sockinfo &si) const 758connection::forward_si (const sockinfo &si) const
… …
751 777
752void 778void
753connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) 779connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
754{ 780{
755 if (!vpn->send_vpn_packet (pkt, si, tos)) 781 if (!vpn->send_vpn_packet (pkt, si, tos))
756 reset_connection (); 782 reset_connection ("packet send error");
757} 783}
758 784
759void 785void
760connection::send_ping (const sockinfo &si, u8 pong) 786connection::send_ping (const sockinfo &si, u8 pong)
761{ 787{
762 ping_packet *pkt = new ping_packet; 788 ping_packet *pkt = new ping_packet;
763 789
764 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING); 790 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING);
765 791
766 slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si); 792 slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si);
767
768 send_vpn_packet (pkt, si, IPTOS_LOWDELAY); 793 send_vpn_packet (pkt, si, IPTOS_LOWDELAY);
769 794
770 delete pkt; 795 delete pkt;
771} 796}
772 797
… …
787void 812void
788connection::send_auth_request (const sockinfo &si, bool initiate) 813connection::send_auth_request (const sockinfo &si, bool initiate)
789{ 814{
790 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols); 815 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols);
791 816
792 rsachallenge chg; 817 generate_auth_data ();
793 rsa_cache.gen (pkt->id, chg);
794 rsa_encrypt (conf->rsa_key, chg, pkt->encr); 818 auth_encrypt (conf->rsa_key, snd_auth, pkt->encr);
795 819
796 slog (L_TRACE, "%s << PT_AUTH_REQ [%s]", conf->nodename, (const char *)si); 820 slog (L_TRACE, "%s << PT_AUTH_REQ [%s]", conf->nodename, (const char *)si);
797
798 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly 821 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly
799 822
800 delete pkt; 823 delete pkt;
801} 824}
802 825
803void 826void
804connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg) 827connection::send_auth_response (const sockinfo &si)
805{ 828{
806 auth_res_packet *pkt = new auth_res_packet (conf->id); 829 auth_res_packet *pkt = new auth_res_packet (conf->id);
807 830
808 pkt->id = id; 831 memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof rcv_ecdh_b);
809 832 auth_hash (rcv_auth, rcv_ecdh_b, pkt->response.mac);
810 rsa_hash (id, chg, pkt->response);
811
812 pkt->hmac_set (octx);
813 833
814 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si); 834 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si);
815
816 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly 835 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly
817 836
818 delete pkt; 837 delete pkt;
819} 838}
820 839
821void 840void
822connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols) 841connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols)
823{ 842{
824 slog (L_TRACE, "%s << PT_CONNECT_INFO(%s,%s)", conf->nodename, 843 slog (L_TRACE, "%s << PT_CONNECT_INFO(%s,%s,p%02x)", conf->nodename,
825 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi); 844 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi,
845 conf->protocols);
826 846
827 connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols); 847 connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols);
828 848
829 r->hmac_set (octx); 849 r->hmac_set (octx);
830 send_vpn_packet (r, si); 850 send_vpn_packet (r, si);
… …
833} 853}
834 854
835inline void 855inline void
836connection::establish_connection_cb (ev::timer &w, int revents) 856connection::establish_connection_cb (ev::timer &w, int revents)
837{ 857{
838 if (!ictx 858 if (!(ictx && octx)
839 && conf != THISNODE 859 && conf != THISNODE
840 && connectmode != conf_node::C_NEVER 860 && connectmode != conf_node::C_NEVER
841 && connectmode != conf_node::C_DISABLED 861 && connectmode != conf_node::C_DISABLED
842 && !w.is_active ()) 862 && !w.is_active ())
843 { 863 {
844 // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection 864 // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection
845 // and stop trying. should probably be handled by a per-connection expire handler. 865 // and stop trying. should probably be handled by a per-connection expire handler.
846 if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ()) 866 if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ())
847 { 867 {
848 reset_connection (); 868 reset_connection ("no demand");
849 return; 869 return;
850 } 870 }
851 871
852 last_establish_attempt = ev_now (); 872 last_establish_attempt = ev_now ();
853 873
… …
855 ? (retry_cnt & 3) + 1 875 ? (retry_cnt & 3) + 1
856 : 1 << (retry_cnt >> 2)); 876 : 1 << (retry_cnt >> 2));
857 877
858 reset_si (); 878 reset_si ();
859 879
860 bool slow = si.prot & PROT_SLOW; 880 bool slow = (si.prot & PROT_SLOW) || (conf->low_power || THISNODE->low_power);
861 881
862 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf)) 882 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf))
863 { 883 {
864 /*TODO*/ /* start the timer so we don't recurse endlessly */ 884 /*TODO*/ /* start the timer so we don't recurse endlessly */
865 w.start (1); 885 w.start (1);
… …
875 895
876 slow = slow || (dsi.prot & PROT_SLOW); 896 slow = slow || (dsi.prot & PROT_SLOW);
877 897
878 if (dsi.valid () && auth_rate_limiter.can (dsi)) 898 if (dsi.valid () && auth_rate_limiter.can (dsi))
879 { 899 {
880 if (retry_cnt < 4) 900 // use ping after the first few retries
901 // TODO: on rekeys, the other node might not interpret ping correctly,
902 // TODO: as it will still have a valid connection
903 if (retry_cnt < 4 && (!conf->low_power || THISNODE->low_power))
881 send_auth_request (dsi, true); 904 send_auth_request (dsi, true);
882 else 905 else
883 send_ping (dsi, 0); 906 send_ping (dsi, 0);
884 } 907 }
885 } 908 }
886 909
887 retry_int *= slow ? 8. : 0.9; 910 retry_int *= slow ? 4. : 0.9;
888 911
889 if (retry_int < conf->max_retry) 912 if (retry_int < conf->max_retry)
890 retry_cnt++; 913 retry_cnt++;
891 else 914 else
892 retry_int = conf->max_retry; 915 retry_int = conf->max_retry;
… …
894 w.start (retry_int); 917 w.start (retry_int);
895 } 918 }
896} 919}
897 920
898void 921void
899connection::reset_connection () 922connection::reset_connection (const char *reason)
900{ 923{
901 if (ictx && octx) 924 if (ictx && octx)
902 { 925 {
903 slog (L_INFO, _("%s(%s): connection lost"), 926 slog (L_INFO, _("%s(%s): connection lost (%s)"),
904 conf->nodename, (const char *)si); 927 conf->nodename, (const char *)si, reason);
905 928
906 if (::conf.script_node_down) 929 if (::conf.script_node_down)
907 { 930 {
908 run_script_cb *cb = new run_script_cb; 931 run_script_cb *cb = new run_script_cb;
909 cb->set<connection, &connection::script_node_down> (this); 932 cb->set<connection, &connection::script_node_down> (this);
… …
911 } 934 }
912 } 935 }
913 936
914 delete ictx; ictx = 0; 937 delete ictx; ictx = 0;
915 delete octx; octx = 0; 938 delete octx; octx = 0;
916#if ENABLE_DNS
917 dnsv4_reset_connection ();
918#endif
919 939
920 si.host = 0; 940 si.host = 0;
941
942 have_snd_auth = false;
943 have_rcv_auth = false;
944 auth_expire = 0.;
921 945
922 last_activity = 0.; 946 last_activity = 0.;
923 //last_si_change = 0.; 947 //last_si_change = 0.;
924 retry_cnt = 0; 948 retry_cnt = 0;
925 949
… …
932connection::shutdown () 956connection::shutdown ()
933{ 957{
934 if (ictx && octx) 958 if (ictx && octx)
935 send_reset (si); 959 send_reset (si);
936 960
937 reset_connection (); 961 reset_connection ("shutdown");
938} 962}
939 963
940// poor-man's rekeying 964// poor-man's rekeying
941inline void 965inline void
942connection::rekey_cb (ev::timer &w, int revents) 966connection::rekey_cb (ev::timer &w, int revents)
943{ 967{
944 reset_connection (); 968 reset_connection ("rekeying");
945 establish_connection (); 969 establish_connection ();
946} 970}
947 971
948void 972void
949connection::send_data_packet (tap_packet *pkt) 973connection::send_data_packet (tap_packet *pkt)
… …
966 990
967void 991void
968connection::post_inject_queue () 992connection::post_inject_queue ()
969{ 993{
970 // force a connection every now and when when packets are sent (max 1/s) 994 // force a connection every now and when when packets are sent (max 1/s)
971 if (ev_now () - last_establish_attempt >= 0.95) // arbitrary 995 if (ev_now () - last_establish_attempt >= (conf->low_power || THISNODE->low_power ? 2.95 : 0.95)) // arbitrary
972 establish_connection.stop (); 996 establish_connection.stop ();
973 997
974 establish_connection (); 998 establish_connection ();
975} 999}
976 1000
… …
984 data_queue.put (new tap_packet (*pkt)); 1008 data_queue.put (new tap_packet (*pkt));
985 post_inject_queue (); 1009 post_inject_queue ();
986 } 1010 }
987} 1011}
988 1012
1013void
989void connection::inject_vpn_packet (vpn_packet *pkt, int tos) 1014connection::inject_vpn_packet (vpn_packet *pkt, int tos)
990{ 1015{
991 if (ictx && octx) 1016 if (ictx && octx)
992 send_vpn_packet (pkt, si, tos); 1017 send_vpn_packet (pkt, si, tos);
993 else 1018 else
994 { 1019 {
… …
1000void 1025void
1001connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi) 1026connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
1002{ 1027{
1003 last_activity = ev_now (); 1028 last_activity = ev_now ();
1004 1029
1005 slog (L_NOISE, "%s >> received packet type %d from %d to %d.", 1030 slog (L_NOISE, "%s >> received packet type %d from %d to %d.",
1006 conf->nodename, pkt->typ (), pkt->src (), pkt->dst ()); 1031 conf->nodename, pkt->typ (), pkt->src (), pkt->dst ());
1007 1032
1008 if (connectmode == conf_node::C_DISABLED) 1033 if (connectmode == conf_node::C_DISABLED)
1009 return; 1034 return;
1010 1035
… …
1014 slog (L_TRACE, "%s >> PT_PING", conf->nodename); 1039 slog (L_TRACE, "%s >> PT_PING", conf->nodename);
1015 1040
1016 // we send pings instead of auth packets after some retries, 1041 // we send pings instead of auth packets after some retries,
1017 // so reset the retry counter and establish a connection 1042 // so reset the retry counter and establish a connection
1018 // when we receive a ping. 1043 // when we receive a ping.
1019 if (!(ictx && octx)) 1044 if (!ictx)
1020 { 1045 {
1021 if (auth_rate_limiter.can (rsi)) 1046 if (auth_rate_limiter.can (rsi))
1022 send_auth_request (rsi, true); 1047 send_auth_request (rsi, true);
1023 } 1048 }
1024 else 1049 else
1025 // we would love to change thre socket address here, but ping's aren't 1050 // we would love to change the socket address here, but ping's aren't
1026 // authenticated, so we best ignore it. 1051 // authenticated, so we best ignore it.
1027 send_ping (rsi, 1); // pong 1052 send_ping (rsi, 1); // pong
1028 1053
1029 break; 1054 break;
1030 1055
1031 case vpn_packet::PT_PONG: 1056 case vpn_packet::PT_PONG:
1032 slog (L_TRACE, "%s >> PT_PONG", conf->nodename); 1057 slog (L_TRACE, "%s >> PT_PONG", conf->nodename);
1058
1059 // a PONG might mean that the other side doesn't really know
1060 // about our desire for communication.
1061 establish_connection ();
1033 break; 1062 break;
1034 1063
1035 case vpn_packet::PT_RESET: 1064 case vpn_packet::PT_RESET:
1065 slog (L_TRACE, "%s >> PT_RESET", conf->nodename);
1066
1067 if (ictx && octx)
1036 { 1068 {
1037 reset_connection (); 1069 reset_connection ("remote reset");
1038 1070
1039 config_packet *p = (config_packet *) pkt; 1071 config_packet *p = (config_packet *) pkt;
1040 1072
1041 if (!p->chk_config ()) 1073 if (p->chk_config (conf, rsi) && connectmode == conf_node::C_ALWAYS)
1042 {
1043 slog (L_WARN, _("%s(%s): protocol mismatch, disabling node."),
1044 conf->nodename, (const char *)rsi);
1045 connectmode = conf_node::C_DISABLED;
1046 }
1047 else if (connectmode == conf_node::C_ALWAYS)
1048 establish_connection (); 1074 establish_connection ();
1049 } 1075 }
1076
1050 break; 1077 break;
1051 1078
1052 case vpn_packet::PT_AUTH_REQ: 1079 case vpn_packet::PT_AUTH_REQ:
1053 if (auth_rate_limiter.can (rsi)) 1080 if (auth_rate_limiter.can (rsi))
1054 { 1081 {
1055 auth_req_packet *p = (auth_req_packet *) pkt; 1082 auth_req_packet *p = (auth_req_packet *)pkt;
1056 1083
1057 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s)", conf->nodename, p->initiate ? "initiate" : "reply"); 1084 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s,p%02x,f%02x)",
1085 conf->nodename, p->initiate ? "initiate" : "reply",
1086 p->protocols, p->features);
1058 1087
1088 if (memcmp (p->magic, MAGIC, 8))
1089 {
1090 slog (L_WARN, _("%s(%s): protocol magic mismatch - stray packet?"),
1091 conf->nodename, (const char *)rsi);
1092 }
1059 if (p->chk_config () 1093 else if (p->chk_config (conf, rsi))
1060 && (!strncmp (p->magic, MAGIC_OLD, 8) || !strncmp (p->magic, MAGIC, 8)))
1061 { 1094 {
1062 if (p->prot_minor != PROTOCOL_MINOR) 1095 if (p->prot_minor != PROTOCOL_MINOR)
1063 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), 1096 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1064 conf->nodename, (const char *)rsi, 1097 conf->nodename, (const char *)rsi,
1065 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 1098 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1066 1099
1067 if (p->initiate) 1100 if (p->initiate)
1101 {
1068 send_auth_request (rsi, false); 1102 send_auth_request (rsi, false);
1069 1103
1070 rsachallenge k; 1104 if (ictx && octx)
1105 reset_connection ("reconnect");
1106 }
1071 1107
1108 auth_data auth;
1109
1072 if (!rsa_decrypt (::conf.rsa_key, p->encr, k)) 1110 if (!auth_decrypt (::conf.rsa_key, p->encr, auth))
1073 { 1111 {
1074 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"), 1112 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"),
1075 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0)); 1113 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0));
1076 break;
1077 } 1114 }
1078 else 1115 else
1079 { 1116 {
1080 delete octx; 1117 bool chg = !have_rcv_auth || !slow_memeq (&rcv_auth, &auth, sizeof auth);
1081 1118
1082 octx = new crypto_ctx (k, 1); 1119 rcv_auth = auth;
1083 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; 1120 have_rcv_auth = true;
1084 1121
1122 send_auth_response (rsi);
1123
1124 if (chg)
1125 {
1085 conf->protocols = p->protocols; 1126 conf->protocols = p->protocols;
1086 features = p->features & config_packet::get_features (); 1127 features = p->features & config_packet::get_features ();
1087 1128
1088 send_auth_response (rsi, p->id, k);
1089
1090 connection_established (); 1129 connection_established (rsi);
1091
1092 break; 1130 }
1093 } 1131 }
1132
1133 break;
1094 } 1134 }
1095 else
1096 slog (L_WARN, _("%s(%s): protocol mismatch."),
1097 conf->nodename, (const char *)rsi);
1098 1135
1099 send_reset (rsi); 1136 send_reset (rsi);
1100 } 1137 }
1101 1138
1102 break; 1139 break;
… …
1105 { 1142 {
1106 auth_res_packet *p = (auth_res_packet *)pkt; 1143 auth_res_packet *p = (auth_res_packet *)pkt;
1107 1144
1108 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename); 1145 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename);
1109 1146
1110 if (p->chk_config ()) 1147 auth_mac local_mac;
1148 auth_hash (snd_auth, p->response.ecdh, local_mac);
1149
1150 if (!slow_memeq (&p->response.mac, local_mac, sizeof local_mac))
1111 { 1151 {
1112 if (p->prot_minor != PROTOCOL_MINOR)
1113 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1114 conf->nodename, (const char *)rsi,
1115 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1116
1117 rsachallenge chg;
1118
1119 if (!rsa_cache.find (p->id, chg))
1120 {
1121 slog (L_ERR, _("%s(%s): unrequested auth response, ignoring."), 1152 slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."),
1122 conf->nodename, (const char *)rsi); 1153 conf->nodename, (const char *)rsi);
1123 break;
1124 } 1154 }
1125 else 1155 else if (!have_snd_auth)
1126 { 1156 {
1127 crypto_ctx *cctx = new crypto_ctx (chg, 0); 1157 memcpy (snd_ecdh_b, p->response.ecdh, sizeof snd_ecdh_b);
1128 1158
1129 if (!p->hmac_chk (cctx)) 1159 have_snd_auth = true;
1130 {
1131 slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n"
1132 "could be an attack, or just corruption or a synchronization error."),
1133 conf->nodename, (const char *)rsi);
1134 break;
1135 }
1136 else
1137 {
1138 rsaresponse h;
1139
1140 rsa_hash (p->id, chg, h);
1141
1142 if (!memcmp ((u8 *)&h, (u8 *)p->response, sizeof h))
1143 {
1144 prot_minor = p->prot_minor;
1145
1146 delete ictx; ictx = cctx;
1147
1148 iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
1149
1150 si = rsi;
1151 protocol = rsi.prot;
1152
1153 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
1154 conf->nodename, (const char *)rsi,
1155 is_direct ? "direct" : "forwarded",
1156 p->prot_major, p->prot_minor);
1157
1158 connection_established (); 1160 connection_established (rsi);
1159
1160 if (::conf.script_node_up)
1161 {
1162 run_script_cb *cb = new run_script_cb;
1163 cb->set<connection, &connection::script_node_up> (this);
1164 run_script_queued (cb, _("node-up command execution failed, continuing."));
1165 }
1166
1167 break;
1168 }
1169 else
1170 slog (L_ERR, _("%s(%s): sent and received challenge do not match."),
1171 conf->nodename, (const char *)rsi);
1172 }
1173
1174 delete cctx;
1175 }
1176 } 1161 }
1177 } 1162 }
1178
1179 send_reset (rsi);
1180 break; 1163 break;
1181 1164
1182 case vpn_packet::PT_DATA_COMPRESSED: 1165 case vpn_packet::PT_DATA_COMPRESSED:
1183#if !ENABLE_COMPRESSION 1166#if !ENABLE_COMPRESSION
1184 send_reset (rsi); 1167 send_reset (rsi);
… …
1190 if (ictx && octx) 1173 if (ictx && octx)
1191 { 1174 {
1192 vpndata_packet *p = (vpndata_packet *)pkt; 1175 vpndata_packet *p = (vpndata_packet *)pkt;
1193 1176
1194 if (!p->hmac_chk (ictx)) 1177 if (!p->hmac_chk (ictx))
1178 {
1179 // rekeying often creates temporary hmac auth floods
1180 // we assume they don't take longer than a few seconds normally,
1181 // and suppress messages and resets during that time.
1182 //TODO: should be done per source address
1183 if (!hmac_error)
1184 {
1185 hmac_error = ev_now () + 3;
1186 break;
1187 }
1188 else if (hmac_error >= ev_now ())
1189 break; // silently suppress
1190 else
1191 {
1195 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n" 1192 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
1196 "could be an attack, or just corruption or a synchronization error."), 1193 "could be an attack, or just corruption or a synchronization error."),
1197 conf->nodename, (const char *)rsi); 1194 conf->nodename, (const char *)rsi);
1195 // reset
1196 }
1197 }
1198 else 1198 else
1199 { 1199 {
1200 u32 seqno; 1200 u32 seqno;
1201 tap_packet *d = p->unpack (this, seqno); 1201 tap_packet *d = p->unpack (this, seqno);
1202 int seqclass = iseqno.seqno_classify (seqno); 1202 int seqclass = iseqno.seqno_classify (seqno);
1203
1204 hmac_error = 0;
1203 1205
1204 if (seqclass == 0) // ok 1206 if (seqclass == 0) // ok
1205 { 1207 {
1206 vpn->tap->send (d); 1208 vpn->tap->send (d);
1207 1209
… …
1257 if (p->id > 0 && p->id <= vpn->conns.size ()) 1259 if (p->id > 0 && p->id <= vpn->conns.size ())
1258 { 1260 {
1259 connection *c = vpn->conns[p->id - 1]; 1261 connection *c = vpn->conns[p->id - 1];
1260 conf->protocols = p->protocols; 1262 conf->protocols = p->protocols;
1261 1263
1262 slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s) [%d]", 1264 slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s,p%02x) [%d]",
1263 conf->nodename, vpn->conns[p->id - 1]->conf->nodename, c->ictx && c->octx); 1265 conf->nodename, vpn->conns[p->id - 1]->conf->nodename,
1266 p->protocols,
1267 c->ictx && c->octx);
1264 1268
1265 if (c->ictx && c->octx) 1269 if (c->ictx && c->octx)
1266 { 1270 {
1267 // send connect_info packets to both sides, in case one is 1271 // send connect_info packets to both sides, in case one is
1268 // behind a nat firewall (or both ;) 1272 // behind a nat firewall (or both ;)
… …
1291 1295
1292 c->conf->protocols = p->protocols; 1296 c->conf->protocols = p->protocols;
1293 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf)); 1297 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf));
1294 p->si.upgrade_protocol (protocol, c->conf); 1298 p->si.upgrade_protocol (protocol, c->conf);
1295 1299
1296 slog (L_TRACE, "%s >> PT_CONNECT_INFO(%s,%s) [%d]", 1300 slog (L_TRACE, "%s >> PT_CONNECT_INFO(%s,%s,protocols=%02x,protocol=%02x,upgradable=%02x) [%d]",
1301 conf->nodename,
1297 conf->nodename, vpn->conns[p->id - 1]->conf->nodename, 1302 vpn->conns[p->id - 1]->conf->nodename,
1303 (const char *)p->si,
1304 p->protocols,
1305 protocol,
1306 p->si.supported_protocols (c->conf),
1298 (const char *)p->si, !c->ictx && !c->octx); 1307 !c->ictx && !c->octx);
1299 1308
1300 const sockinfo &dsi = forward_si (p->si); 1309 const sockinfo &dsi = forward_si (p->si);
1301 1310
1302 if (dsi.valid ()) 1311 if (dsi.valid ())
1303 c->send_auth_request (dsi, true); 1312 c->send_auth_request (dsi, true);
1313 else
1314 slog (L_INFO, "connect info for %s received (%s), but still unable to contact.",
1315 vpn->conns[p->id - 1]->conf->nodename,
1316 (const char *)p->si);
1304 } 1317 }
1305 else 1318 else
1306 slog (L_WARN, 1319 slog (L_WARN,
1307 _("received authenticated connection request from unknown node #%d, config file mismatch?"), 1320 _("received authenticated connection request from unknown node #%d, config file mismatch?"),
1308 p->id); 1321 p->id);
… …
1317} 1330}
1318 1331
1319inline void 1332inline void
1320connection::keepalive_cb (ev::timer &w, int revents) 1333connection::keepalive_cb (ev::timer &w, int revents)
1321{ 1334{
1322 if (ev_now () >= last_activity + ::conf.keepalive + 15) 1335 ev_tstamp when = last_activity + ::conf.keepalive - ev::now ();
1336
1337 if (when >= 0)
1338 w.start (when);
1339 else if (when < -15)
1323 { 1340 {
1324 reset_connection (); 1341 reset_connection ("keepalive overdue");
1325 establish_connection (); 1342 establish_connection ();
1326 } 1343 }
1327 else if (ev_now () < last_activity + ::conf.keepalive)
1328 w.start (last_activity + ::conf.keepalive - ev::now ());
1329 else if (conf->connectmode != conf_node::C_ONDEMAND 1344 else if (conf->connectmode != conf_node::C_ONDEMAND
1330 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1345 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1331 { 1346 {
1347 w.start (3);
1332 send_ping (si); 1348 send_ping (si);
1333 w.start (3);
1334 } 1349 }
1335 else if (ev_now () < last_activity + ::conf.keepalive + 10) 1350 else if (when >= -10)
1336 // hold ondemand connections implicitly a few seconds longer 1351 // hold ondemand connections implicitly a few seconds longer
1337 // should delete octx, though, or something like that ;) 1352 // should delete octx, though, or something like that ;)
1338 w.start (last_activity + ::conf.keepalive + 10 - ev::now ()); 1353 w.start (when + 10);
1339 else 1354 else
1340 reset_connection (); 1355 reset_connection ("keepalive timeout");
1341} 1356}
1342 1357
1358void
1343void connection::send_connect_request (int id) 1359connection::send_connect_request (int id)
1344{ 1360{
1345 connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols); 1361 connect_req_packet *p = new connect_req_packet (conf->id, id, THISNODE->protocols);
1346 1362
1347 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s)", 1363 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s,p%02x)",
1348 conf->nodename, vpn->conns[id - 1]->conf->nodename); 1364 conf->nodename, vpn->conns[id - 1]->conf->nodename,
1365 THISNODE->protocols);
1349 p->hmac_set (octx); 1366 p->hmac_set (octx);
1350 send_vpn_packet (p, si); 1367 send_vpn_packet (p, si);
1351 1368
1352 delete p; 1369 delete p;
1353} 1370}
1354 1371
1372void
1355void connection::script_init_env (const char *ext) 1373connection::script_init_env (const char *ext)
1356{ 1374{
1357 char *env; 1375 char *env;
1358 asprintf (&env, "IFUPDATA%s=%s", ext, conf->if_up_data); putenv (env); 1376 asprintf (&env, "IFUPDATA%s=%s", ext, conf->if_up_data); putenv (env);
1359 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env); 1377 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env);
1360 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext, 1378 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext,
1361 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8, 1379 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8,
1362 conf->id & 0xff); putenv (env); 1380 conf->id & 0xff); putenv (env);
1363} 1381}
1364 1382
1383void
1365void connection::script_init_connect_env () 1384connection::script_init_connect_env ()
1366{ 1385{
1367 vpn->script_init_env (); 1386 vpn->script_init_env ();
1368 1387
1369 char *env; 1388 char *env;
1370 asprintf (&env, "DESTID=%d", conf->id); putenv (env); 1389 asprintf (&env, "DESTID=%d", conf->id); putenv (env);
… …
1435 establish_connection.set<connection, &connection::establish_connection_cb> (this); 1454 establish_connection.set<connection, &connection::establish_connection_cb> (this);
1436 1455
1437 last_establish_attempt = 0.; 1456 last_establish_attempt = 0.;
1438 octx = ictx = 0; 1457 octx = ictx = 0;
1439 1458
1440 if (!conf->protocols) // make sure some protocol is enabled
1441 conf->protocols = PROT_UDPv4;
1442
1443 connectmode = conf->connectmode; 1459 connectmode = conf->connectmode;
1444 1460
1445 // queue a dummy packet to force an initial connection attempt 1461 // queue a dummy packet to force an initial connection attempt
1446 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED) 1462 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED)
1447 vpn_queue.put (new net_packet); 1463 vpn_queue.put (new net_packet);
1448 1464
1449 reset_connection (); 1465 reset_connection ("startup");
1450} 1466}
1451 1467
1452connection::~connection () 1468connection::~connection ()
1453{ 1469{
1454 shutdown (); 1470 shutdown ();
1455} 1471}
1456 1472
1473void
1457void connection_init () 1474connection_init ()
1458{ 1475{
1459 auth_rate_limiter.clear (); 1476 auth_rate_limiter.clear ();
1460 reset_rate_limiter.clear (); 1477 reset_rate_limiter.clear ();
1461} 1478}
1462 1479

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