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Comparing gvpe/src/connection.C (file contents):
Revision 1.81 by pcg, Fri Aug 15 18:31:13 2008 UTC vs.
Revision 1.116 by root, Mon Apr 1 03:10:26 2019 UTC

1/* 1/*
2 connection.C -- manage a single connection 2 connection.C -- manage a single connection
3 Copyright (C) 2003-2008 Marc Lehmann <gvpe@schmorp.de> 3 Copyright (C) 2003-2008,2010,2011,2013,2016 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>
42 43
43#include "conf.h" 44#include "conf.h"
44#include "slog.h" 45#include "slog.h"
46#include "crypto.h"
45#include "device.h" 47#include "device.h"
46#include "vpn.h" 48#include "vpn.h"
47#include "connection.h" 49#include "connection.h"
50#include "hkdf.h"
48 51
49#include "netcompat.h" 52#include "netcompat.h"
50 53
51#if !HAVE_RAND_PSEUDO_BYTES
52# define RAND_pseudo_bytes RAND_bytes
53#endif
54
55#define MAGIC "vped\xbd\xc6\xdb\x82" // 8 bytes of magic 54#define MAGIC "gvpe\xbd\xc6\xdb\x82" // 8 bytes of magic
56 55
56#define LZF_STATE_ARG 1
57#define ULTRA_FAST 1 57#define ULTRA_FAST 1
58#define HLOG 15 58#define HLOG 15
59#include "lzf/lzf.h" 59#define INIT_HTAB 0
60#include "lzf/lzf_c.c" 60#include "lzf/lzf_c.c"
61#include "lzf/lzf_d.c" 61#include "lzf/lzf_d.c"
62 62
63////////////////////////////////////////////////////////////////////////////// 63//////////////////////////////////////////////////////////////////////////////
64 64
65static std::queue< std::pair<run_script_cb *, const char *> > rs_queue; 65static std::queue< std::pair<run_script_cb *, const char *> > rs_queue;
66static ev::child rs_child_ev; 66static ev::child rs_child_ev;
67 67
68namespace
69{
68void // c++ requires external linkage here, apparently :( 70 void // c++ requires external linkage here, apparently :(
69rs_child_cb (ev::child &w, int revents) 71 rs_child_cb (ev::child &w, int revents)
70{ 72 {
71 w.stop (); 73 w.stop ();
72 74
73 if (rs_queue.empty ()) 75 if (rs_queue.empty ())
74 return; 76 return;
75 77
76 pid_t pid = run_script (*rs_queue.front ().first, false); 78 pid_t pid = run_script (*rs_queue.front ().first, false);
77 if (pid) 79 if (pid)
78 { 80 {
79 w.set (pid); 81 w.set (pid);
80 w.start (); 82 w.start ();
81 } 83 }
82 else 84 else
83 slog (L_WARN, rs_queue.front ().second); 85 slog (L_WARN, rs_queue.front ().second);
84 86
85 delete rs_queue.front ().first; 87 delete rs_queue.front ().first;
86 rs_queue.pop (); 88 rs_queue.pop ();
87} 89 }
90};
88 91
89// despite the fancy name, this is quite a hack 92// despite the fancy name, this is quite a hack
90static void 93static void
91run_script_queued (run_script_cb *cb, const char *warnmsg) 94run_script_queued (run_script_cb *cb, const char *warnmsg)
92{ 95{
… …
101 104
102////////////////////////////////////////////////////////////////////////////// 105//////////////////////////////////////////////////////////////////////////////
103 106
104struct crypto_ctx 107struct crypto_ctx
105{ 108{
106 EVP_CIPHER_CTX cctx; 109 cipher cctx;
107 HMAC_CTX hctx; 110 hmac hctx;
108 111
109 crypto_ctx (const rsachallenge &challenge, int enc); 112 crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc);
110 ~crypto_ctx (); 113 ~crypto_ctx ();
111}; 114};
112 115
113crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc) 116crypto_ctx::crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc)
114{ 117{
118 ecdh_key s;
119
120 curve25519_combine (a, b, s);
121
122 {
123 u8 mac_key[MAC_KEYSIZE];
124 static const unsigned char mac_info[] = "gvpe mac key";
125
126 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
127 kdf.extract (auth1.rsa.mac_key, sizeof (auth1.rsa.mac_key));
128 kdf.extract (s, sizeof (s));
129 kdf.extract_done (HKDF_PRF_HASH ());
130 kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info));
131
132 hctx.init (mac_key, MAC_KEYSIZE, MAC_DIGEST ());
133 }
134
135 {
136 u8 cipher_key[CIPHER_KEYSIZE];
137 static const unsigned char cipher_info[] = "gvpe cipher key";
138
139 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
140 kdf.extract (auth1.rsa.cipher_key, sizeof (auth1.rsa.cipher_key));
141 kdf.extract (s, sizeof (s));
142 kdf.extract_done (HKDF_PRF_HASH ());
143 kdf.expand (cipher_key, sizeof (cipher_key), cipher_info, sizeof (cipher_info));
144
115 EVP_CIPHER_CTX_init (&cctx); 145 EVP_CIPHER_CTX_init (cctx);
116 require (EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc)); 146 require (EVP_CipherInit_ex (cctx, CIPHER (), 0, cipher_key, 0, enc));
117 HMAC_CTX_init (&hctx); 147 }
118 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
119} 148}
120 149
121crypto_ctx::~crypto_ctx () 150crypto_ctx::~crypto_ctx ()
122{ 151{
123 require (EVP_CIPHER_CTX_cleanup (&cctx)); 152 require (EVP_CIPHER_CTX_cleanup (cctx));
124 HMAC_CTX_cleanup (&hctx); 153}
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;
125} 180}
126 181
127static void 182static void
128rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h) 183auth_hash (const auth_data &auth, const ecdh_key &b, auth_mac &mac)
129{ 184{
130 EVP_MD_CTX ctx; 185 hkdf kdf (b, sizeof b, AUTH_DIGEST ()); // use response ecdh b as salt
131 186 kdf.extract (&auth.rsa, sizeof (auth.rsa));
132 EVP_MD_CTX_init (&ctx); 187 kdf.extract_done ();
133 require (EVP_DigestInit (&ctx, RSA_HASH)); 188 kdf.expand (mac, sizeof mac, auth.ecdh, sizeof (auth.ecdh)); // use challenge ecdh b as info
134 require (EVP_DigestUpdate(&ctx, &chg, sizeof chg));
135 require (EVP_DigestUpdate(&ctx, &id, sizeof id));
136 require (EVP_DigestFinal (&ctx, (unsigned char *)&h, 0));
137 EVP_MD_CTX_cleanup (&ctx);
138} 189}
139 190
140struct rsa_entry 191void
192connection::generate_auth_data ()
141{ 193{
142 tstamp expire; 194 if (auth_expire < ev_now ())
143 rsaid id;
144 rsachallenge chg;
145};
146
147struct rsa_cache : list<rsa_entry>
148{
149 inline void cleaner_cb (ev::timer &w, int revents); ev::timer cleaner;
150
151 bool find (const rsaid &id, rsachallenge &chg)
152 {
153 for (iterator i = begin (); i != end (); ++i)
154 { 195 {
155 if (!memcmp (&id, &i->id, sizeof id) && i->expire > ev_now ()) 196 // request data
156 { 197 rand_fill (snd_auth.rsa);
157 memcpy (&chg, &i->chg, sizeof chg); 198 curve25519_generate (snd_ecdh_a, snd_auth.ecdh);
158 199
159 erase (i); 200 // eventual response data
160 return true; 201 curve25519_generate (rcv_ecdh_a, rcv_ecdh_b);
161 }
162 } 202 }
163 203
164 if (!cleaner.is_active ()) 204 // every use prolongs the expiry
165 cleaner.again ();
166
167 return false;
168 }
169
170 void gen (rsaid &id, rsachallenge &chg)
171 {
172 rsa_entry e;
173
174 RAND_bytes ((unsigned char *)&id, sizeof id);
175 RAND_bytes ((unsigned char *)&chg, sizeof chg);
176
177 e.expire = ev_now () + RSA_TTL; 205 auth_expire = ev_now () + AUTH_TTL;
178 e.id = id;
179 memcpy (&e.chg, &chg, sizeof chg);
180
181 push_back (e);
182
183 if (!cleaner.is_active ())
184 cleaner.again ();
185 }
186
187 rsa_cache ()
188 {
189 cleaner.set<rsa_cache, &rsa_cache::cleaner_cb> (this);
190 cleaner.set (RSA_TTL, RSA_TTL);
191 }
192
193} rsa_cache;
194
195void rsa_cache::cleaner_cb (ev::timer &w, int revents)
196{
197 if (empty ())
198 w.stop ();
199 else
200 {
201 for (iterator i = begin (); i != end (); )
202 if (i->expire <= ev_now ())
203 i = erase (i);
204 else
205 ++i;
206 }
207} 206}
208 207
209////////////////////////////////////////////////////////////////////////////// 208//////////////////////////////////////////////////////////////////////////////
210 209
211pkt_queue::pkt_queue (double max_ttl, int max_queue) 210pkt_queue::pkt_queue (double max_ttl, int max_queue)
… …
225 delete p; 224 delete p;
226 225
227 delete [] queue; 226 delete [] queue;
228} 227}
229 228
229void
230void pkt_queue::expire_cb (ev::timer &w, int revents) 230pkt_queue::expire_cb (ev::timer &w, int revents)
231{ 231{
232 ev_tstamp expire = ev_now () - max_ttl; 232 ev_tstamp expire = ev_now () - max_ttl;
233 233
234 for (;;) 234 for (;;)
235 { 235 {
… …
246 246
247 delete get (); 247 delete get ();
248 } 248 }
249} 249}
250 250
251void
251void pkt_queue::put (net_packet *p) 252pkt_queue::put (net_packet *p)
252{ 253{
253 ev_tstamp now = ev_now (); 254 ev_tstamp now = ev_now ();
254 255
255 // start expiry timer 256 // start expiry timer
256 if (empty ()) 257 if (empty ())
… …
265 queue[i].tstamp = now; 266 queue[i].tstamp = now;
266 267
267 i = ni; 268 i = ni;
268} 269}
269 270
270net_packet *pkt_queue::get () 271net_packet *
272pkt_queue::get ()
271{ 273{
272 if (empty ()) 274 if (empty ())
273 return 0; 275 return 0;
274 276
275 net_packet *p = queue[j].pkt; 277 net_packet *p = queue[j].pkt;
… …
299 301
300 bool can (const sockinfo &si) { return can((u32)si.host); } 302 bool can (const sockinfo &si) { return can((u32)si.host); }
301 bool can (u32 host); 303 bool can (u32 host);
302}; 304};
303 305
304net_rate_limiter auth_rate_limiter, reset_rate_limiter; 306static net_rate_limiter auth_rate_limiter, reset_rate_limiter;
305 307
308bool
306bool net_rate_limiter::can (u32 host) 309net_rate_limiter::can (u32 host)
307{ 310{
308 iterator i; 311 iterator i;
309 312
310 for (i = begin (); i != end (); ) 313 for (i = begin (); i != end (); )
311 if (i->host == host) 314 if (i->host == host)
… …
356 } 359 }
357} 360}
358 361
359///////////////////////////////////////////////////////////////////////////// 362/////////////////////////////////////////////////////////////////////////////
360 363
361unsigned char hmac_packet::hmac_digest[EVP_MAX_MD_SIZE]; 364void
362
363void hmac_packet::hmac_gen (crypto_ctx *ctx) 365hmac_packet::hmac_gen (crypto_ctx *ctx, u8 *hmac_digest)
364{ 366{
365 unsigned int xlen; 367 ctx->hctx.init ();
366 368 ctx->hctx.add (((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet));
367 HMAC_CTX *hctx = &ctx->hctx; 369 ctx->hctx.digest (hmac_digest);
368
369 HMAC_Init_ex (hctx, 0, 0, 0, 0);
370 HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet),
371 len - sizeof (hmac_packet));
372 HMAC_Final (hctx, (unsigned char *) &hmac_digest, &xlen);
373} 370}
374 371
375void 372void
376hmac_packet::hmac_set (crypto_ctx *ctx) 373hmac_packet::hmac_set (crypto_ctx *ctx)
377{ 374{
378 hmac_gen (ctx); 375 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
379 376 hmac_gen (ctx, hmac_digest);
380 memcpy (hmac, hmac_digest, HMACLENGTH); 377 memcpy (hmac, hmac_digest, HMACLENGTH);
381} 378}
382 379
383bool 380bool
384hmac_packet::hmac_chk (crypto_ctx *ctx) 381hmac_packet::hmac_chk (crypto_ctx *ctx)
385{ 382{
386 hmac_gen (ctx); 383 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
387 384 hmac_gen (ctx, hmac_digest);
388 return !memcmp (hmac, hmac_digest, HMACLENGTH); 385 return slow_memeq (hmac, hmac_digest, HMACLENGTH);
389} 386}
390 387
388void
391void vpn_packet::set_hdr (ptype type_, unsigned int dst) 389vpn_packet::set_hdr (ptype type_, unsigned int dst)
392{ 390{
393 type = type_; 391 type = type_;
394 392
395 int src = THISNODE->id; 393 int src = THISNODE->id;
396 394
… …
398 srcdst = ((src >> 8) << 4) | (dst >> 8); 396 srcdst = ((src >> 8) << 4) | (dst >> 8);
399 dst1 = dst; 397 dst1 = dst;
400} 398}
401 399
402#define MAXVPNDATA (MAX_MTU - 6 - 6) 400#define MAXVPNDATA (MAX_MTU - 6 - 6)
403#define DATAHDR (sizeof (u32) + RAND_SIZE)
404 401
405struct vpndata_packet : vpn_packet 402struct vpndata_packet : vpn_packet
403{
404 u32 ctr; // seqno
405 u8 data[MAXVPNDATA];
406
407 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
408 tap_packet *unpack (connection *conn, u32 &seqno);
409
410private:
411 const u32 data_hdr_size () const
406 { 412 {
407 u8 data[MAXVPNDATA + DATAHDR]; // seqno 413 // the distance from beginning of packet to data member
408 414 return data - at (0);
409 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
410 tap_packet *unpack (connection *conn, u32 &seqno);
411private:
412
413 const u32 data_hdr_size () const
414 {
415 return sizeof (vpndata_packet) - sizeof (net_packet) - MAXVPNDATA - DATAHDR;
416 }
417 }; 415 }
416};
417
418// expands packet counter (unlike seqno, in network byte order) to counter mode IV
419static unsigned char *
420expand_iv (u32 ctr)
421{
422 static u32 iv[IV_SIZE (CIPHER) / 4];
423
424 require (sizeof (iv) == 4 * 4);
425 require (IV_SIZE (CIPHER) % 4 == 0);
426
427 iv[0] =
428 iv[1] =
429 iv[2] = ctr;
430
431 // I would reuse ctr here to to avoid potential endianness issues,
432 // but it seems openssl wraps around. While this would be still ok,
433 // and I don't even know if its true, let's play safe and initialise
434 // to 0.
435 iv[3] = 0;
436
437 return (unsigned char *)iv;
438}
418 439
419void 440void
420vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno) 441vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno)
421{ 442{
422 EVP_CIPHER_CTX *cctx = &conn->octx->cctx; 443 EVP_CIPHER_CTX *cctx = conn->octx->cctx;
423 int outl = 0, outl2; 444 int outl = 0, outl2;
424 ptype type = PT_DATA_UNCOMPRESSED; 445 ptype type = PT_DATA_UNCOMPRESSED;
425 446
426#if ENABLE_COMPRESSION 447#if ENABLE_COMPRESSION
427 u8 cdata[MAX_MTU]; 448 u8 cdata[MAX_MTU];
428 449
429 if (conn->features & ENABLE_COMPRESSION) 450 if (conn->features & FEATURE_COMPRESSION)
430 { 451 {
452 static LZF_STATE lzf_state;
431 u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7); 453 u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7, lzf_state);
432 454
433 if (cl) 455 if (cl)
434 { 456 {
435 type = PT_DATA_COMPRESSED; 457 type = PT_DATA_COMPRESSED;
436 d = cdata; 458 d = cdata;
… …
440 d[1] = cl; 462 d[1] = cl;
441 } 463 }
442 } 464 }
443#endif 465#endif
444 466
467 ctr = htonl (seqno);
468
445 require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0)); 469 require (EVP_EncryptInit_ex (cctx, 0, 0, 0, expand_iv (ctr)));
446
447 struct {
448#if RAND_SIZE
449 u8 rnd[RAND_SIZE];
450#endif
451 u32 seqno;
452 } datahdr;
453
454 datahdr.seqno = ntohl (seqno);
455#if RAND_SIZE
456 RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE);
457#endif
458 470
459 require (EVP_EncryptUpdate (cctx, 471 require (EVP_EncryptUpdate (cctx,
460 (unsigned char *) data + outl, &outl2, 472 (unsigned char *)data + outl, &outl2,
461 (unsigned char *) &datahdr, DATAHDR)); 473 (unsigned char *)d, l));
462 outl += outl2; 474 outl += outl2;
463 475
464 require (EVP_EncryptUpdate (cctx, 476 // it seems this is a nop for us, but we do it anyways
465 (unsigned char *) data + outl, &outl2, 477 require (EVP_EncryptFinal_ex (cctx, (unsigned char *)data + outl, &outl2));
466 (unsigned char *) d, l));
467 outl += outl2; 478 outl += outl2;
468 479
469 require (EVP_EncryptFinal_ex (cctx, (unsigned char *) data + outl, &outl2));
470 outl += outl2;
471
472 len = outl + data_hdr_size (); 480 len = data_hdr_size () + outl;
473 481
474 set_hdr (type, dst); 482 set_hdr (type, dst);
475 483
476 hmac_set (conn->octx); 484 hmac_set (conn->octx);
477} 485}
478 486
479tap_packet * 487tap_packet *
480vpndata_packet::unpack (connection *conn, u32 &seqno) 488vpndata_packet::unpack (connection *conn, u32 &seqno)
481{ 489{
482 EVP_CIPHER_CTX *cctx = &conn->ictx->cctx; 490 EVP_CIPHER_CTX *cctx = conn->ictx->cctx;
483 int outl = 0, outl2; 491 int outl = 0, outl2;
484 tap_packet *p = new tap_packet; 492 tap_packet *p = new tap_packet;
485 u8 *d; 493 u8 *d;
486 u32 l = len - data_hdr_size ();
487 494
495 seqno = ntohl (ctr);
496
488 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, 0)); 497 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, expand_iv (ctr)));
489 498
490#if ENABLE_COMPRESSION 499#if ENABLE_COMPRESSION
491 u8 cdata[MAX_MTU]; 500 u8 cdata[MAX_MTU];
492 501
493 if (type == PT_DATA_COMPRESSED) 502 if (type == PT_DATA_COMPRESSED)
494 d = cdata; 503 d = cdata;
495 else 504 else
496#endif 505#endif
497 d = &(*p)[6 + 6 - DATAHDR]; 506 d = &(*p)[6 + 6];
498 507
499 /* this overwrites part of the src mac, but we fix that later */ 508 // this can overwrite the len/dst/src fields
500 require (EVP_DecryptUpdate (cctx, 509 require (EVP_DecryptUpdate (cctx,
501 d, &outl2, 510 d, &outl2,
502 (unsigned char *)&data, len - data_hdr_size ())); 511 (unsigned char *)&data, len - data_hdr_size ()));
503 outl += outl2; 512 outl += outl2;
504 513
514 // it seems this is a nop for us, but we do it anyways
505 require (EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2)); 515 require (EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2));
506 outl += outl2; 516 outl += outl2;
507 517
508 seqno = ntohl (*(u32 *)(d + RAND_SIZE));
509
510 id2mac (dst () ? dst() : THISNODE->id, p->dst); 518 id2mac (dst () ? dst() : THISNODE->id, p->dst);
511 id2mac (src (), p->src); 519 id2mac (src (), p->src);
512 520
513#if ENABLE_COMPRESSION 521#if ENABLE_COMPRESSION
514 if (type == PT_DATA_COMPRESSED) 522 if (type == PT_DATA_COMPRESSED)
515 { 523 {
516 u32 cl = (d[DATAHDR] << 8) | d[DATAHDR + 1]; 524 u32 cl = (d[0] << 8) | d[1];
517 525
518 p->len = lzf_decompress (d + DATAHDR + 2, cl < MAX_MTU ? cl : 0, 526 p->len = lzf_decompress (d + 2, cl < MAX_MTU - 2 ? cl : 0,
519 &(*p)[6 + 6], MAX_MTU) 527 &(*p)[6 + 6], MAX_MTU)
520 + 6 + 6; 528 + 6 + 6;
521 } 529 }
522 else 530 else
523 p->len = outl + (6 + 6 - DATAHDR); 531 p->len = outl + (6 + 6);
524#endif 532#endif
525 533
526 return p; 534 return p;
527} 535}
528 536
… …
535 } 543 }
536}; 544};
537 545
538struct config_packet : vpn_packet 546struct config_packet : vpn_packet
539{ 547{
540 // actually, hmaclen cannot be checked because the hmac 548 u8 serial[SERIAL_SIZE];
541 // field comes before this data, so peers with other
542 // hmacs simply will not work.
543 u8 prot_major, prot_minor, randsize, hmaclen; 549 u8 prot_major, prot_minor, randsize;
544 u8 flags, challengelen, features, pad3; 550 u8 flags, features, pad6, pad7, pad8;
545 u32 cipher_nid, digest_nid, hmac_nid; 551 u32 cipher_nid, mac_nid, auth_nid;
546 552
547 void setup (ptype type, int dst); 553 void setup (ptype type, int dst);
548 bool chk_config () const; 554 bool chk_config (const conf_node *conf, const sockinfo &rsi) const;
549 555
550 static u8 get_features () 556 static u8 get_features ()
551 { 557 {
552 u8 f = 0; 558 u8 f = 0;
553#if ENABLE_COMPRESSION 559#if ENABLE_COMPRESSION
… …
561#endif 567#endif
562 return f; 568 return f;
563 } 569 }
564}; 570};
565 571
572void
566void config_packet::setup (ptype type, int dst) 573config_packet::setup (ptype type, int dst)
567{ 574{
568 prot_major = PROTOCOL_MAJOR; 575 prot_major = PROTOCOL_MAJOR;
569 prot_minor = PROTOCOL_MINOR; 576 prot_minor = PROTOCOL_MINOR;
570 randsize = RAND_SIZE;
571 hmaclen = HMACLENGTH;
572 flags = 0; 577 flags = 0;
573 challengelen = sizeof (rsachallenge);
574 features = get_features (); 578 features = get_features ();
575 579
580 strncpy ((char *)serial, conf.serial, sizeof (serial));
581
576 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER)); 582 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ()));
577 digest_nid = htonl (EVP_MD_type (RSA_HASH));
578 hmac_nid = htonl (EVP_MD_type (DIGEST)); 583 mac_nid = htonl (EVP_MD_type (MAC_DIGEST ()));
584 auth_nid = htonl (EVP_MD_type (AUTH_DIGEST ()));
579 585
580 len = sizeof (*this) - sizeof (net_packet); 586 len = sizeof (*this) - sizeof (net_packet);
581 set_hdr (type, dst); 587 set_hdr (type, dst);
582} 588}
583 589
584bool config_packet::chk_config () const 590bool
591config_packet::chk_config (const conf_node *conf, const sockinfo &rsi) const
585{ 592{
586 if (prot_major != PROTOCOL_MAJOR) 593 if (prot_major != PROTOCOL_MAJOR)
587 slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR); 594 slog (L_WARN, _("%s(%s): major version mismatch (remote %d <=> local %d)"),
588 else if (randsize != RAND_SIZE) 595 conf->nodename, (const char *)rsi, prot_major, PROTOCOL_MAJOR);
589 slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE);
590 else if (hmaclen != HMACLENGTH)
591 slog (L_WARN, _("hmac length mismatch (remote %d <=> local %d)"), hmaclen, HMACLENGTH);
592 else if (challengelen != sizeof (rsachallenge))
593 slog (L_WARN, _("challenge length mismatch (remote %d <=> local %d)"), challengelen, sizeof (rsachallenge));
594 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER))) 596 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER ())))
595 slog (L_WARN, _("cipher mismatch (remote %x <=> local %x)"), ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER)); 597 slog (L_WARN, _("%s(%s): cipher algo mismatch (remote %x <=> local %x)"),
596 else if (digest_nid != htonl (EVP_MD_type (RSA_HASH))) 598 conf->nodename, (const char *)rsi, ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER ()));
597 slog (L_WARN, _("digest mismatch (remote %x <=> local %x)"), ntohl (digest_nid), EVP_MD_type (RSA_HASH));
598 else if (hmac_nid != htonl (EVP_MD_type (DIGEST))) 599 else if (mac_nid != htonl (EVP_MD_type (MAC_DIGEST ())))
599 slog (L_WARN, _("hmac mismatch (remote %x <=> local %x)"), ntohl (hmac_nid), EVP_MD_type (DIGEST)); 600 slog (L_WARN, _("%s(%s): mac algo mismatch (remote %x <=> local %x)"),
601 conf->nodename, (const char *)rsi, ntohl (mac_nid), EVP_MD_type (MAC_DIGEST ()));
602 else if (auth_nid != htonl (EVP_MD_type (AUTH_DIGEST ())))
603 slog (L_WARN, _("%s(%s): auth algo mismatch (remote %x <=> local %x)"),
604 conf->nodename, (const char *)rsi, ntohl (auth_nid), EVP_MD_type (AUTH_DIGEST ()));
600 else 605 else
606 {
607 int cmp = memcmp (serial, ::conf.serial, sizeof (serial));
608
609 if (cmp > 0)
610 slog (L_WARN, _("%s(%s): remote serial newer than local serial - outdated config?"),
611 conf->nodename, (const char *)rsi);
612 else if (cmp == 0)
601 return true; 613 return true;
614 }
602 615
603 return false; 616 return false;
604} 617}
605 618
606struct auth_req_packet : config_packet 619struct auth_req_packet : config_packet // UNPROTECTED
607{ 620{
608 char magic[8]; 621 char magic[8];
609 u8 initiate; // false if this is just an automatic reply 622 u8 initiate; // false if this is just an automatic reply
610 u8 protocols; // supported protocols (will be patched on forward) 623 u8 protocols; // supported protocols (will be patched on forward)
611 u8 pad2, pad3; 624 u8 pad2, pad3;
612 rsaid id; 625 auth_encr encr;
613 rsaencrdata encr;
614 626
615 auth_req_packet (int dst, bool initiate_, u8 protocols_) 627 auth_req_packet (int dst, bool initiate_, u8 protocols_)
616 { 628 {
617 config_packet::setup (PT_AUTH_REQ, dst); 629 config_packet::setup (PT_AUTH_REQ, dst);
618 strncpy (magic, MAGIC, 8); 630 memcpy (magic, MAGIC, 8);
619 initiate = !!initiate_; 631 initiate = !!initiate_;
620 protocols = protocols_; 632 protocols = protocols_;
621 633
622 len = sizeof (*this) - sizeof (net_packet); 634 len = sizeof (*this) - sizeof (net_packet);
623 } 635 }
624}; 636};
625 637
626struct auth_res_packet : config_packet 638struct auth_res_packet : vpn_packet // UNPROTECTED
627{ 639{
628 rsaid id;
629 u8 pad1, pad2, pad3;
630 u8 response_len; // encrypted length
631 rsaresponse response; 640 auth_response response;
632 641
633 auth_res_packet (int dst) 642 auth_res_packet (int dst)
634 { 643 {
635 config_packet::setup (PT_AUTH_RES, dst); 644 set_hdr (PT_AUTH_RES, dst);
636 645
637 len = sizeof (*this) - sizeof (net_packet); 646 len = sizeof (*this) - sizeof (net_packet);
638 } 647 }
639}; 648};
640 649
… …
670}; 679};
671 680
672///////////////////////////////////////////////////////////////////////////// 681/////////////////////////////////////////////////////////////////////////////
673 682
674void 683void
675connection::connection_established () 684connection::connection_established (const sockinfo &rsi)
676{ 685{
677 slog (L_NOISE, _("%s: possible connection establish (ictx %d, octx %d)"), conf->nodename, !!ictx, !!octx); 686 if (!have_snd_auth || !have_rcv_auth)
687 return;
678 688
679 if (ictx && octx) 689 si = rsi;
690 protocol = rsi.prot;
691
692 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
693 conf->nodename, (const char *)rsi,
694 vpn->can_direct (THISNODE, conf) ? "direct" : "forwarded",
695 PROTOCOL_MAJOR, prot_minor);
696
697 if (::conf.script_node_up)
698 {
699 run_script_cb *cb = new run_script_cb;
700 cb->set<connection, &connection::script_node_up> (this);
701 run_script_queued (cb, _("node-up command execution failed, continuing."));
680 { 702 }
703
704 delete ictx; ictx = new crypto_ctx (rcv_auth, snd_auth, rcv_ecdh_a, rcv_auth.ecdh, 0);
705 iseqno.reset (ntohl (rcv_auth.rsa.seqno) & 0x7fffffff);
706
707 delete octx; octx = new crypto_ctx (snd_auth, rcv_auth, snd_ecdh_a, snd_ecdh_b , 1);
708 oseqno = ntohl (snd_auth.rsa.seqno) & 0x7fffffff;
709
681 // make sure rekeying timeouts are slightly asymmetric 710 // make sure rekeying timeouts are slightly asymmetric
682 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0); 711 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0);
683 rekey.start (rekey_interval, rekey_interval); 712 rekey.start (rekey_interval, rekey_interval);
713
714 hmac_error = 0.;
715
684 keepalive.start (::conf.keepalive); 716 keepalive.start (::conf.keepalive);
685 717
686 // send queued packets 718 // send queued packets
687 if (ictx && octx)
688 {
689 while (tap_packet *p = (tap_packet *)data_queue.get ()) 719 while (tap_packet *p = (tap_packet *)data_queue.get ())
690 { 720 {
691 if (p->len) send_data_packet (p); 721 if (p->len) send_data_packet (p);
692 delete p; 722 delete p;
693 } 723 }
694 724
695 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) 725 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
696 { 726 {
697 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY); 727 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
698 delete p; 728 delete p;
699 } 729 }
700 }
701 730
702 vpn->connection_established (this); 731 vpn->connection_established (this);
703 }
704 else
705 {
706 retry_cnt = 0;
707 establish_connection.start (5);
708 keepalive.stop ();
709 rekey.stop ();
710 }
711} 732}
712 733
713void 734void
714connection::reset_si () 735connection::reset_si ()
715{ 736{
… …
720 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename); 741 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename);
721 protocol = 0; 742 protocol = 0;
722 } 743 }
723 744
724 si.set (conf, protocol); 745 si.set (conf, protocol);
725
726 is_direct = si.valid ();
727} 746}
728 747
729// ensure sockinfo is valid, forward if necessary 748// ensure sockinfo is valid, forward if necessary
730const sockinfo & 749const sockinfo &
731connection::forward_si (const sockinfo &si) const 750connection::forward_si (const sockinfo &si) const
… …
750 769
751void 770void
752connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) 771connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
753{ 772{
754 if (!vpn->send_vpn_packet (pkt, si, tos)) 773 if (!vpn->send_vpn_packet (pkt, si, tos))
755 reset_connection (); 774 reset_connection ("packet send error");
756} 775}
757 776
758void 777void
759connection::send_ping (const sockinfo &si, u8 pong) 778connection::send_ping (const sockinfo &si, u8 pong)
760{ 779{
761 ping_packet *pkt = new ping_packet; 780 ping_packet *pkt = new ping_packet;
762 781
763 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING); 782 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING);
764 783
765 slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si); 784 slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si);
766
767 send_vpn_packet (pkt, si, IPTOS_LOWDELAY); 785 send_vpn_packet (pkt, si, IPTOS_LOWDELAY);
768 786
769 delete pkt; 787 delete pkt;
770} 788}
771 789
… …
786void 804void
787connection::send_auth_request (const sockinfo &si, bool initiate) 805connection::send_auth_request (const sockinfo &si, bool initiate)
788{ 806{
789 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols); 807 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols);
790 808
791 rsachallenge chg; 809 generate_auth_data ();
792 rsa_cache.gen (pkt->id, chg);
793 rsa_encrypt (conf->rsa_key, chg, pkt->encr); 810 auth_encrypt (conf->rsa_key, snd_auth, pkt->encr);
794 811
795 slog (L_TRACE, "%s << PT_AUTH_REQ [%s]", conf->nodename, (const char *)si); 812 slog (L_TRACE, "%s << PT_AUTH_REQ [%s]", conf->nodename, (const char *)si);
796
797 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly 813 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly
798 814
799 delete pkt; 815 delete pkt;
800} 816}
801 817
802void 818void
803connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg) 819connection::send_auth_response (const sockinfo &si)
804{ 820{
805 auth_res_packet *pkt = new auth_res_packet (conf->id); 821 auth_res_packet *pkt = new auth_res_packet (conf->id);
806 822
807 pkt->id = id; 823 memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof rcv_ecdh_b);
808 824 auth_hash (rcv_auth, rcv_ecdh_b, pkt->response.mac);
809 rsa_hash (id, chg, pkt->response);
810
811 pkt->hmac_set (octx);
812 825
813 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si); 826 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si);
814
815 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly 827 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly
816 828
817 delete pkt; 829 delete pkt;
818} 830}
819 831
820void 832void
821connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols) 833connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols)
822{ 834{
823 slog (L_TRACE, "%s << PT_CONNECT_INFO(%s,%s)", conf->nodename, 835 slog (L_TRACE, "%s << PT_CONNECT_INFO(%s,%s,p%02x)", conf->nodename,
824 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi); 836 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi,
837 conf->protocols);
825 838
826 connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols); 839 connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols);
827 840
828 r->hmac_set (octx); 841 r->hmac_set (octx);
829 send_vpn_packet (r, si); 842 send_vpn_packet (r, si);
… …
832} 845}
833 846
834inline void 847inline void
835connection::establish_connection_cb (ev::timer &w, int revents) 848connection::establish_connection_cb (ev::timer &w, int revents)
836{ 849{
837 if (!ictx 850 if (!(ictx && octx)
838 && conf != THISNODE 851 && conf != THISNODE
839 && connectmode != conf_node::C_NEVER 852 && connectmode != conf_node::C_NEVER
840 && connectmode != conf_node::C_DISABLED 853 && connectmode != conf_node::C_DISABLED
841 && !w.is_active ()) 854 && !w.is_active ())
842 { 855 {
843 // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection 856 // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection
844 // and stop trying. should probably be handled by a per-connection expire handler. 857 // and stop trying. should probably be handled by a per-connection expire handler.
845 if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ()) 858 if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ())
846 { 859 {
847 reset_connection (); 860 reset_connection ("no demand");
848 return; 861 return;
849 } 862 }
850 863
851 last_establish_attempt = ev_now (); 864 last_establish_attempt = ev_now ();
852 865
… …
854 ? (retry_cnt & 3) + 1 867 ? (retry_cnt & 3) + 1
855 : 1 << (retry_cnt >> 2)); 868 : 1 << (retry_cnt >> 2));
856 869
857 reset_si (); 870 reset_si ();
858 871
859 bool slow = si.prot & PROT_SLOW; 872 bool slow = (si.prot & PROT_SLOW) || (conf->low_power || THISNODE->low_power);
860 873
861 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf)) 874 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf))
862 { 875 {
863 /*TODO*/ /* start the timer so we don't recurse endlessly */ 876 /*TODO*/ /* start the timer so we don't recurse endlessly */
864 w.start (1); 877 w.start (1);
… …
874 887
875 slow = slow || (dsi.prot & PROT_SLOW); 888 slow = slow || (dsi.prot & PROT_SLOW);
876 889
877 if (dsi.valid () && auth_rate_limiter.can (dsi)) 890 if (dsi.valid () && auth_rate_limiter.can (dsi))
878 { 891 {
879 if (retry_cnt < 4) 892 // use ping after the first few retries
893 // TODO: on rekeys, the other node might not interpret ping correctly,
894 // TODO: as it will still have a valid connection
895 if (retry_cnt < 4 && (!conf->low_power || THISNODE->low_power))
880 send_auth_request (dsi, true); 896 send_auth_request (dsi, true);
881 else 897 else
882 send_ping (dsi, 0); 898 send_ping (dsi, 0);
883 } 899 }
884 } 900 }
885 901
886 retry_int *= slow ? 8. : 0.9; 902 retry_int *= slow ? 4. : 0.9;
887 903
888 if (retry_int < conf->max_retry) 904 if (retry_int < conf->max_retry)
889 retry_cnt++; 905 retry_cnt++;
890 else 906 else
891 retry_int = conf->max_retry; 907 retry_int = conf->max_retry;
… …
893 w.start (retry_int); 909 w.start (retry_int);
894 } 910 }
895} 911}
896 912
897void 913void
898connection::reset_connection () 914connection::reset_connection (const char *reason)
899{ 915{
900 if (ictx && octx) 916 if (ictx && octx)
901 { 917 {
902 slog (L_INFO, _("%s(%s): connection lost"), 918 slog (L_INFO, _("%s(%s): connection lost (%s)"),
903 conf->nodename, (const char *)si); 919 conf->nodename, (const char *)si, reason);
904 920
905 if (::conf.script_node_down) 921 if (::conf.script_node_down)
906 { 922 {
907 run_script_cb *cb = new run_script_cb; 923 run_script_cb *cb = new run_script_cb;
908 cb->set<connection, &connection::script_node_down> (this); 924 cb->set<connection, &connection::script_node_down> (this);
… …
910 } 926 }
911 } 927 }
912 928
913 delete ictx; ictx = 0; 929 delete ictx; ictx = 0;
914 delete octx; octx = 0; 930 delete octx; octx = 0;
915#if ENABLE_DNS
916 dnsv4_reset_connection ();
917#endif
918 931
919 si.host = 0; 932 si.host = 0;
933
934 have_snd_auth = false;
935 have_rcv_auth = false;
936 auth_expire = 0.;
920 937
921 last_activity = 0.; 938 last_activity = 0.;
922 //last_si_change = 0.; 939 //last_si_change = 0.;
923 retry_cnt = 0; 940 retry_cnt = 0;
924 941
… …
931connection::shutdown () 948connection::shutdown ()
932{ 949{
933 if (ictx && octx) 950 if (ictx && octx)
934 send_reset (si); 951 send_reset (si);
935 952
936 reset_connection (); 953 reset_connection ("shutdown");
937} 954}
938 955
939// poor-man's rekeying 956// poor-man's rekeying
940inline void 957inline void
941connection::rekey_cb (ev::timer &w, int revents) 958connection::rekey_cb (ev::timer &w, int revents)
942{ 959{
943 reset_connection (); 960 reset_connection ("rekeying");
944 establish_connection (); 961 establish_connection ();
945} 962}
946 963
947void 964void
948connection::send_data_packet (tap_packet *pkt) 965connection::send_data_packet (tap_packet *pkt)
… …
965 982
966void 983void
967connection::post_inject_queue () 984connection::post_inject_queue ()
968{ 985{
969 // force a connection every now and when when packets are sent (max 1/s) 986 // force a connection every now and when when packets are sent (max 1/s)
970 if (ev_now () - last_establish_attempt >= 0.95) // arbitrary 987 if (ev_now () - last_establish_attempt >= (conf->low_power || THISNODE->low_power ? 2.95 : 0.95)) // arbitrary
971 establish_connection.stop (); 988 establish_connection.stop ();
972 989
973 establish_connection (); 990 establish_connection ();
974} 991}
975 992
… …
983 data_queue.put (new tap_packet (*pkt)); 1000 data_queue.put (new tap_packet (*pkt));
984 post_inject_queue (); 1001 post_inject_queue ();
985 } 1002 }
986} 1003}
987 1004
1005void
988void connection::inject_vpn_packet (vpn_packet *pkt, int tos) 1006connection::inject_vpn_packet (vpn_packet *pkt, int tos)
989{ 1007{
990 if (ictx && octx) 1008 if (ictx && octx)
991 send_vpn_packet (pkt, si, tos); 1009 send_vpn_packet (pkt, si, tos);
992 else 1010 else
993 { 1011 {
… …
999void 1017void
1000connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi) 1018connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
1001{ 1019{
1002 last_activity = ev_now (); 1020 last_activity = ev_now ();
1003 1021
1004 slog (L_NOISE, "%s >> received packet type %d from %d to %d.", 1022 slog (L_NOISE, "%s >> received packet type %d from %d to %d.",
1005 conf->nodename, pkt->typ (), pkt->src (), pkt->dst ()); 1023 conf->nodename, pkt->typ (), pkt->src (), pkt->dst ());
1006 1024
1007 if (connectmode == conf_node::C_DISABLED) 1025 if (connectmode == conf_node::C_DISABLED)
1008 return; 1026 return;
1009 1027
… …
1019 { 1037 {
1020 if (auth_rate_limiter.can (rsi)) 1038 if (auth_rate_limiter.can (rsi))
1021 send_auth_request (rsi, true); 1039 send_auth_request (rsi, true);
1022 } 1040 }
1023 else 1041 else
1024 // we would love to change thre socket address here, but ping's aren't 1042 // we would love to change the socket address here, but ping's aren't
1025 // authenticated, so we best ignore it. 1043 // authenticated, so we best ignore it.
1026 send_ping (rsi, 1); // pong 1044 send_ping (rsi, 1); // pong
1027 1045
1028 break; 1046 break;
1029 1047
1030 case vpn_packet::PT_PONG: 1048 case vpn_packet::PT_PONG:
1031 slog (L_TRACE, "%s >> PT_PONG", conf->nodename); 1049 slog (L_TRACE, "%s >> PT_PONG", conf->nodename);
1050
1051 // a PONG might mean that the other side doesn't really know
1052 // about our desire for communication.
1053 establish_connection ();
1032 break; 1054 break;
1033 1055
1034 case vpn_packet::PT_RESET: 1056 case vpn_packet::PT_RESET:
1057 slog (L_TRACE, "%s >> PT_RESET", conf->nodename);
1058
1059 if (ictx && octx)
1035 { 1060 {
1036 reset_connection (); 1061 reset_connection ("remote reset");
1037 1062
1038 config_packet *p = (config_packet *) pkt; 1063 config_packet *p = (config_packet *) pkt;
1039 1064
1040 if (!p->chk_config ()) 1065 if (p->chk_config (conf, rsi) && connectmode == conf_node::C_ALWAYS)
1041 {
1042 slog (L_WARN, _("%s(%s): protocol mismatch, disabling node."),
1043 conf->nodename, (const char *)rsi);
1044 connectmode = conf_node::C_DISABLED;
1045 }
1046 else if (connectmode == conf_node::C_ALWAYS)
1047 establish_connection (); 1066 establish_connection ();
1048 } 1067 }
1068
1049 break; 1069 break;
1050 1070
1051 case vpn_packet::PT_AUTH_REQ: 1071 case vpn_packet::PT_AUTH_REQ:
1052 if (auth_rate_limiter.can (rsi)) 1072 if (auth_rate_limiter.can (rsi))
1053 { 1073 {
1054 auth_req_packet *p = (auth_req_packet *) pkt; 1074 auth_req_packet *p = (auth_req_packet *)pkt;
1055 1075
1056 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s)", conf->nodename, p->initiate ? "initiate" : "reply"); 1076 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s,p%02x,f%02x)",
1077 conf->nodename, p->initiate ? "initiate" : "reply",
1078 p->protocols, p->features);
1057 1079
1058 if (p->chk_config () && !strncmp (p->magic, MAGIC, 8)) 1080 if (memcmp (p->magic, MAGIC, 8))
1081 {
1082 slog (L_WARN, _("%s(%s): protocol magic mismatch - stray packet?"),
1083 conf->nodename, (const char *)rsi);
1084 }
1085 else if (p->chk_config (conf, rsi))
1059 { 1086 {
1060 if (p->prot_minor != PROTOCOL_MINOR) 1087 if (p->prot_minor != PROTOCOL_MINOR)
1061 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), 1088 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1062 conf->nodename, (const char *)rsi, 1089 conf->nodename, (const char *)rsi,
1063 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 1090 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1064 1091
1065 if (p->initiate) 1092 if (p->initiate)
1093 {
1066 send_auth_request (rsi, false); 1094 send_auth_request (rsi, false);
1067 1095
1068 rsachallenge k; 1096 if (ictx && octx)
1097 reset_connection ("reconnect");
1098 }
1069 1099
1100 auth_data auth;
1101
1070 if (!rsa_decrypt (::conf.rsa_key, p->encr, k)) 1102 if (!auth_decrypt (::conf.rsa_key, p->encr, auth))
1071 { 1103 {
1072 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"), 1104 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"),
1073 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0)); 1105 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0));
1074 break;
1075 } 1106 }
1076 else 1107 else
1077 { 1108 {
1078 delete octx; 1109 bool chg = !have_rcv_auth || !slow_memeq (&rcv_auth, &auth, sizeof auth);
1079 1110
1080 octx = new crypto_ctx (k, 1); 1111 rcv_auth = auth;
1081 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; 1112 have_rcv_auth = true;
1082 1113
1114 send_auth_response (rsi);
1115
1116 if (chg)
1117 {
1083 conf->protocols = p->protocols; 1118 conf->protocols = p->protocols;
1084 features = p->features & config_packet::get_features (); 1119 features = p->features & config_packet::get_features ();
1085 1120
1086 send_auth_response (rsi, p->id, k);
1087
1088 connection_established (); 1121 connection_established (rsi);
1089
1090 break; 1122 }
1091 } 1123 }
1124
1125 break;
1092 } 1126 }
1093 else
1094 slog (L_WARN, _("%s(%s): protocol mismatch."),
1095 conf->nodename, (const char *)rsi);
1096 1127
1097 send_reset (rsi); 1128 send_reset (rsi);
1098 } 1129 }
1099 1130
1100 break; 1131 break;
… …
1103 { 1134 {
1104 auth_res_packet *p = (auth_res_packet *)pkt; 1135 auth_res_packet *p = (auth_res_packet *)pkt;
1105 1136
1106 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename); 1137 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename);
1107 1138
1108 if (p->chk_config ()) 1139 auth_mac local_mac;
1140 auth_hash (snd_auth, p->response.ecdh, local_mac);
1141
1142 if (!slow_memeq (&p->response.mac, local_mac, sizeof local_mac))
1109 { 1143 {
1110 if (p->prot_minor != PROTOCOL_MINOR)
1111 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1112 conf->nodename, (const char *)rsi,
1113 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1114
1115 rsachallenge chg;
1116
1117 if (!rsa_cache.find (p->id, chg))
1118 {
1119 slog (L_ERR, _("%s(%s): unrequested auth response, ignoring."), 1144 slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."),
1120 conf->nodename, (const char *)rsi); 1145 conf->nodename, (const char *)rsi);
1121 break;
1122 } 1146 }
1123 else 1147 else if (!have_snd_auth)
1124 { 1148 {
1125 crypto_ctx *cctx = new crypto_ctx (chg, 0); 1149 memcpy (snd_ecdh_b, p->response.ecdh, sizeof snd_ecdh_b);
1126 1150
1127 if (!p->hmac_chk (cctx)) 1151 have_snd_auth = true;
1128 {
1129 slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n"
1130 "could be an attack, or just corruption or a synchronization error."),
1131 conf->nodename, (const char *)rsi);
1132 break;
1133 }
1134 else
1135 {
1136 rsaresponse h;
1137
1138 rsa_hash (p->id, chg, h);
1139
1140 if (!memcmp ((u8 *)&h, (u8 *)p->response, sizeof h))
1141 {
1142 prot_minor = p->prot_minor;
1143
1144 delete ictx; ictx = cctx;
1145
1146 iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
1147
1148 si = rsi;
1149 protocol = rsi.prot;
1150
1151 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
1152 conf->nodename, (const char *)rsi,
1153 is_direct ? "direct" : "routed",
1154 p->prot_major, p->prot_minor);
1155
1156 connection_established (); 1152 connection_established (rsi);
1157
1158 if (::conf.script_node_up)
1159 {
1160 run_script_cb *cb = new run_script_cb;
1161 cb->set<connection, &connection::script_node_up> (this);
1162 run_script_queued (cb, _("node-up command execution failed, continuing."));
1163 }
1164
1165 break;
1166 }
1167 else
1168 slog (L_ERR, _("%s(%s): sent and received challenge do not match."),
1169 conf->nodename, (const char *)rsi);
1170 }
1171
1172 delete cctx;
1173 }
1174 } 1153 }
1175 } 1154 }
1176
1177 send_reset (rsi);
1178 break; 1155 break;
1179 1156
1180 case vpn_packet::PT_DATA_COMPRESSED: 1157 case vpn_packet::PT_DATA_COMPRESSED:
1181#if !ENABLE_COMPRESSION 1158#if !ENABLE_COMPRESSION
1182 send_reset (rsi); 1159 send_reset (rsi);
… …
1188 if (ictx && octx) 1165 if (ictx && octx)
1189 { 1166 {
1190 vpndata_packet *p = (vpndata_packet *)pkt; 1167 vpndata_packet *p = (vpndata_packet *)pkt;
1191 1168
1192 if (!p->hmac_chk (ictx)) 1169 if (!p->hmac_chk (ictx))
1170 {
1171 // rekeying often creates temporary hmac auth floods
1172 // we assume they don't take longer than a few seconds normally,
1173 // and suppress messages and resets during that time.
1174 //TODO: should be done per source address
1175 if (!hmac_error)
1176 {
1177 hmac_error = ev_now () + 3;
1178 break;
1179 }
1180 else if (hmac_error >= ev_now ())
1181 break; // silently suppress
1182 else
1183 {
1193 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n" 1184 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
1194 "could be an attack, or just corruption or a synchronization error."), 1185 "could be an attack, or just corruption or a synchronization error."),
1195 conf->nodename, (const char *)rsi); 1186 conf->nodename, (const char *)rsi);
1187 // reset
1188 }
1189 }
1196 else 1190 else
1197 { 1191 {
1198 u32 seqno; 1192 u32 seqno;
1199 tap_packet *d = p->unpack (this, seqno); 1193 tap_packet *d = p->unpack (this, seqno);
1200 int seqclass = iseqno.seqno_classify (seqno); 1194 int seqclass = iseqno.seqno_classify (seqno);
1195
1196 hmac_error = 0;
1201 1197
1202 if (seqclass == 0) // ok 1198 if (seqclass == 0) // ok
1203 { 1199 {
1204 vpn->tap->send (d); 1200 vpn->tap->send (d);
1205 1201
… …
1210 // { 1206 // {
1211 slog (L_INFO, _("%s(%s): changing socket address to %s."), 1207 slog (L_INFO, _("%s(%s): changing socket address to %s."),
1212 conf->nodename, (const char *)si, (const char *)rsi); 1208 conf->nodename, (const char *)si, (const char *)rsi);
1213 1209
1214 si = rsi; 1210 si = rsi;
1211
1212 if (::conf.script_node_change)
1213 {
1214 run_script_cb *cb = new run_script_cb;
1215 cb->set<connection, &connection::script_node_change> (this);
1216 run_script_queued (cb, _("node-change command execution failed, continuing."));
1217 }
1218
1215 // } 1219 // }
1216 //else 1220 //else
1217 // slog (L_INFO, _("%s(%s): accepted packet from %s, not (yet) redirecting traffic."), 1221 // slog (L_INFO, _("%s(%s): accepted packet from %s, not (yet) redirecting traffic."),
1218 // conf->nodename, (const char *)si, (const char *)rsi); 1222 // conf->nodename, (const char *)si, (const char *)rsi);
1219 } 1223 }
… …
1240 break; 1244 break;
1241 1245
1242 case vpn_packet::PT_CONNECT_REQ: 1246 case vpn_packet::PT_CONNECT_REQ:
1243 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx)) 1247 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx))
1244 { 1248 {
1245 connect_req_packet *p = (connect_req_packet *) pkt; 1249 connect_req_packet *p = (connect_req_packet *)pkt;
1246 1250
1247 if (p->id > 0 && p->id <= vpn->conns.size ()) 1251 if (p->id > 0 && p->id <= vpn->conns.size ())
1248 { 1252 {
1249 connection *c = vpn->conns[p->id - 1]; 1253 connection *c = vpn->conns[p->id - 1];
1250 conf->protocols = p->protocols; 1254 conf->protocols = p->protocols;
1251 1255
1252 slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s) [%d]", 1256 slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s,p%02x) [%d]",
1253 conf->nodename, vpn->conns[p->id - 1]->conf->nodename, c->ictx && c->octx); 1257 conf->nodename, vpn->conns[p->id - 1]->conf->nodename,
1258 p->protocols,
1259 c->ictx && c->octx);
1254 1260
1255 if (c->ictx && c->octx) 1261 if (c->ictx && c->octx)
1256 { 1262 {
1257 // send connect_info packets to both sides, in case one is 1263 // send connect_info packets to both sides, in case one is
1258 // behind a nat firewall (or both ;) 1264 // behind a nat firewall (or both ;)
… …
1281 1287
1282 c->conf->protocols = p->protocols; 1288 c->conf->protocols = p->protocols;
1283 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf)); 1289 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf));
1284 p->si.upgrade_protocol (protocol, c->conf); 1290 p->si.upgrade_protocol (protocol, c->conf);
1285 1291
1286 slog (L_TRACE, "%s >> PT_CONNECT_INFO(%s,%s) [%d]", 1292 slog (L_TRACE, "%s >> PT_CONNECT_INFO(%s,%s,protocols=%02x,protocol=%02x,upgradable=%02x) [%d]",
1293 conf->nodename,
1287 conf->nodename, vpn->conns[p->id - 1]->conf->nodename, 1294 vpn->conns[p->id - 1]->conf->nodename,
1295 (const char *)p->si,
1296 p->protocols,
1297 protocol,
1298 p->si.supported_protocols (c->conf),
1288 (const char *)p->si, !c->ictx && !c->octx); 1299 !c->ictx && !c->octx);
1289 1300
1290 const sockinfo &dsi = forward_si (p->si); 1301 const sockinfo &dsi = forward_si (p->si);
1291 1302
1292 if (dsi.valid ()) 1303 if (dsi.valid ())
1293 c->send_auth_request (dsi, true); 1304 c->send_auth_request (dsi, true);
1305 else
1306 slog (L_INFO, "connect info for %s received (%s), but still unable to contact.",
1307 vpn->conns[p->id - 1]->conf->nodename,
1308 (const char *)p->si);
1294 } 1309 }
1295 else 1310 else
1296 slog (L_WARN, 1311 slog (L_WARN,
1297 _("received authenticated connection request from unknown node #%d, config file mismatch?"), 1312 _("received authenticated connection request from unknown node #%d, config file mismatch?"),
1298 p->id); 1313 p->id);
… …
1307} 1322}
1308 1323
1309inline void 1324inline void
1310connection::keepalive_cb (ev::timer &w, int revents) 1325connection::keepalive_cb (ev::timer &w, int revents)
1311{ 1326{
1312 if (ev_now () >= last_activity + ::conf.keepalive + 30) 1327 ev_tstamp when = last_activity + ::conf.keepalive - ev::now ();
1328
1329 if (when >= 0)
1330 w.start (when);
1331 else if (when < -15)
1313 { 1332 {
1314 reset_connection (); 1333 reset_connection ("keepalive overdue");
1315 establish_connection (); 1334 establish_connection ();
1316 } 1335 }
1317 else if (ev_now () < last_activity + ::conf.keepalive)
1318 w.start (last_activity + ::conf.keepalive - ev::now ());
1319 else if (conf->connectmode != conf_node::C_ONDEMAND 1336 else if (conf->connectmode != conf_node::C_ONDEMAND
1320 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1337 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1321 { 1338 {
1339 w.start (3);
1322 send_ping (si); 1340 send_ping (si);
1323 w.start (5);
1324 } 1341 }
1325 else if (ev_now () < last_activity + ::conf.keepalive + 10) 1342 else if (when >= -10)
1326 // hold ondemand connections implicitly a few seconds longer 1343 // hold ondemand connections implicitly a few seconds longer
1327 // should delete octx, though, or something like that ;) 1344 // should delete octx, though, or something like that ;)
1328 w.start (last_activity + ::conf.keepalive + 10 - ev::now ()); 1345 w.start (when + 10);
1329 else 1346 else
1330 reset_connection (); 1347 reset_connection ("keepalive timeout");
1331} 1348}
1332 1349
1350void
1333void connection::send_connect_request (int id) 1351connection::send_connect_request (int id)
1334{ 1352{
1335 connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols); 1353 connect_req_packet *p = new connect_req_packet (conf->id, id, THISNODE->protocols);
1336 1354
1337 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s)", 1355 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s,p%02x)",
1338 conf->nodename, vpn->conns[id - 1]->conf->nodename); 1356 conf->nodename, vpn->conns[id - 1]->conf->nodename,
1357 THISNODE->protocols);
1339 p->hmac_set (octx); 1358 p->hmac_set (octx);
1340 send_vpn_packet (p, si); 1359 send_vpn_packet (p, si);
1341 1360
1342 delete p; 1361 delete p;
1343} 1362}
1344 1363
1364void
1345void connection::script_init_env (const char *ext) 1365connection::script_init_env (const char *ext)
1346{ 1366{
1347 char *env; 1367 char *env;
1348 asprintf (&env, "IFUPDATA%s=%s", ext, conf->if_up_data); putenv (env); 1368 asprintf (&env, "IFUPDATA%s=%s", ext, conf->if_up_data); putenv (env);
1349 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env); 1369 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env);
1350 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext, 1370 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext,
1351 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8, 1371 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8,
1352 conf->id & 0xff); putenv (env); 1372 conf->id & 0xff); putenv (env);
1353} 1373}
1354 1374
1375void
1355void connection::script_init_connect_env () 1376connection::script_init_connect_env ()
1356{ 1377{
1357 vpn->script_init_env (); 1378 vpn->script_init_env ();
1358 1379
1359 char *env; 1380 char *env;
1360 asprintf (&env, "DESTID=%d", conf->id); putenv (env); 1381 asprintf (&env, "DESTID=%d", conf->id); putenv (env);
1382 asprintf (&env, "DESTSI=%s", (const char *)si); putenv (env);
1361 asprintf (&env, "DESTNODE=%s", conf->nodename); putenv (env); 1383 asprintf (&env, "DESTNODE=%s", conf->nodename); putenv (env);
1362 asprintf (&env, "DESTIP=%s", si.ntoa ()); putenv (env); 1384 asprintf (&env, "DESTIP=%s", si.ntoa ()); putenv (env);
1363 asprintf (&env, "DESTPORT=%d", ntohs (si.port)); putenv (env); 1385 asprintf (&env, "DESTPORT=%d", ntohs (si.port)); putenv (env);
1364} 1386}
1365 1387
1366inline const char * 1388inline const char *
1367connection::script_node_up () 1389connection::script_node_up ()
1368{ 1390{
… …
1373 char *filename; 1395 char *filename;
1374 asprintf (&filename, 1396 asprintf (&filename,
1375 "%s/%s", 1397 "%s/%s",
1376 confbase, 1398 confbase,
1377 ::conf.script_node_up ? ::conf.script_node_up : "node-up"); 1399 ::conf.script_node_up ? ::conf.script_node_up : "node-up");
1400
1401 return filename;
1402}
1403
1404inline const char *
1405connection::script_node_change ()
1406{
1407 script_init_connect_env ();
1408
1409 putenv ((char *)"STATE=change");
1410
1411 char *filename;
1412 asprintf (&filename,
1413 "%s/%s",
1414 confbase,
1415 ::conf.script_node_change ? ::conf.script_node_change : "node-change");
1378 1416
1379 return filename; 1417 return filename;
1380} 1418}
1381 1419
1382inline const char * 1420inline const char *
… …
1408 establish_connection.set<connection, &connection::establish_connection_cb> (this); 1446 establish_connection.set<connection, &connection::establish_connection_cb> (this);
1409 1447
1410 last_establish_attempt = 0.; 1448 last_establish_attempt = 0.;
1411 octx = ictx = 0; 1449 octx = ictx = 0;
1412 1450
1413 if (!conf->protocols) // make sure some protocol is enabled
1414 conf->protocols = PROT_UDPv4;
1415
1416 connectmode = conf->connectmode; 1451 connectmode = conf->connectmode;
1417 1452
1418 // queue a dummy packet to force an initial connection attempt 1453 // queue a dummy packet to force an initial connection attempt
1419 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED) 1454 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED)
1420 vpn_queue.put (new net_packet); 1455 vpn_queue.put (new net_packet);
1421 1456
1422 reset_connection (); 1457 reset_connection ("startup");
1423} 1458}
1424 1459
1425connection::~connection () 1460connection::~connection ()
1426{ 1461{
1427 shutdown (); 1462 shutdown ();
1428} 1463}
1429 1464
1465void
1430void connection_init () 1466connection_init ()
1431{ 1467{
1432 auth_rate_limiter.clear (); 1468 auth_rate_limiter.clear ();
1433 reset_rate_limiter.clear (); 1469 reset_rate_limiter.clear ();
1434} 1470}
1435 1471

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