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Comparing gvpe/src/connection.C (file contents):
Revision 1.89 by root, Thu Dec 2 08:15:09 2010 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) 2003-2008,2010 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_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) 54#define MAGIC "gvpe\xbd\xc6\xdb\x82" // 8 bytes of magic
57 55
56#define LZF_STATE_ARG 1
58#define ULTRA_FAST 1 57#define ULTRA_FAST 1
59#define HLOG 15 58#define HLOG 15
60#include "lzf/lzf.h" 59#define INIT_HTAB 0
61#include "lzf/lzf_c.c" 60#include "lzf/lzf_c.c"
62#include "lzf/lzf_d.c" 61#include "lzf/lzf_d.c"
63 62
64////////////////////////////////////////////////////////////////////////////// 63//////////////////////////////////////////////////////////////////////////////
65 64
66static std::queue< std::pair<run_script_cb *, const char *> > rs_queue; 65static std::queue< std::pair<run_script_cb *, const char *> > rs_queue;
67static ev::child rs_child_ev; 66static ev::child rs_child_ev;
68 67
68namespace
69{
69void // c++ requires external linkage here, apparently :( 70 void // c++ requires external linkage here, apparently :(
70rs_child_cb (ev::child &w, int revents) 71 rs_child_cb (ev::child &w, int revents)
71{ 72 {
72 w.stop (); 73 w.stop ();
73 74
74 if (rs_queue.empty ()) 75 if (rs_queue.empty ())
75 return; 76 return;
76 77
77 pid_t pid = run_script (*rs_queue.front ().first, false); 78 pid_t pid = run_script (*rs_queue.front ().first, false);
78 if (pid) 79 if (pid)
79 { 80 {
80 w.set (pid); 81 w.set (pid);
81 w.start (); 82 w.start ();
82 } 83 }
83 else 84 else
84 slog (L_WARN, rs_queue.front ().second); 85 slog (L_WARN, rs_queue.front ().second);
85 86
86 delete rs_queue.front ().first; 87 delete rs_queue.front ().first;
87 rs_queue.pop (); 88 rs_queue.pop ();
88} 89 }
90};
89 91
90// despite the fancy name, this is quite a hack 92// despite the fancy name, this is quite a hack
91static void 93static void
92run_script_queued (run_script_cb *cb, const char *warnmsg) 94run_script_queued (run_script_cb *cb, const char *warnmsg)
93{ 95{
… …
102 104
103////////////////////////////////////////////////////////////////////////////// 105//////////////////////////////////////////////////////////////////////////////
104 106
105struct crypto_ctx 107struct crypto_ctx
106{ 108{
107 EVP_CIPHER_CTX cctx; 109 cipher cctx;
108 HMAC_CTX hctx; 110 hmac hctx;
109 111
110 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);
111 ~crypto_ctx (); 113 ~crypto_ctx ();
112}; 114};
113 115
114crypto_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)
115{ 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
116 EVP_CIPHER_CTX_init (&cctx); 145 EVP_CIPHER_CTX_init (cctx);
117 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));
118 HMAC_CTX_init (&hctx); 147 }
119 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
120} 148}
121 149
122crypto_ctx::~crypto_ctx () 150crypto_ctx::~crypto_ctx ()
123{ 151{
124 require (EVP_CIPHER_CTX_cleanup (&cctx)); 152 require (EVP_CIPHER_CTX_cleanup (cctx));
125 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;
126} 180}
127 181
128static void 182static void
129rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h) 183auth_hash (const auth_data &auth, const ecdh_key &b, auth_mac &mac)
130{ 184{
131 EVP_MD_CTX ctx; 185 hkdf kdf (b, sizeof b, AUTH_DIGEST ()); // use response ecdh b as salt
132 186 kdf.extract (&auth.rsa, sizeof (auth.rsa));
133 EVP_MD_CTX_init (&ctx); 187 kdf.extract_done ();
134 require (EVP_DigestInit (&ctx, RSA_HASH)); 188 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} 189}
140 190
141struct rsa_entry 191void
192connection::generate_auth_data ()
142{ 193{
143 tstamp expire; 194 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 { 195 {
156 if (!memcmp (&id, &i->id, sizeof id) && i->expire > ev_now ()) 196 // request data
157 { 197 rand_fill (snd_auth.rsa);
158 memcpy (&chg, &i->chg, sizeof chg); 198 curve25519_generate (snd_ecdh_a, snd_auth.ecdh);
159 199
160 erase (i); 200 // eventual response data
161 return true; 201 curve25519_generate (rcv_ecdh_a, rcv_ecdh_b);
162 }
163 } 202 }
164 203
165 if (!cleaner.is_active ()) 204 // 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; 205 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} 206}
209 207
210////////////////////////////////////////////////////////////////////////////// 208//////////////////////////////////////////////////////////////////////////////
211 209
212pkt_queue::pkt_queue (double max_ttl, int max_queue) 210pkt_queue::pkt_queue (double max_ttl, int max_queue)
… …
226 delete p; 224 delete p;
227 225
228 delete [] queue; 226 delete [] queue;
229} 227}
230 228
229void
231void pkt_queue::expire_cb (ev::timer &w, int revents) 230pkt_queue::expire_cb (ev::timer &w, int revents)
232{ 231{
233 ev_tstamp expire = ev_now () - max_ttl; 232 ev_tstamp expire = ev_now () - max_ttl;
234 233
235 for (;;) 234 for (;;)
236 { 235 {
… …
247 246
248 delete get (); 247 delete get ();
249 } 248 }
250} 249}
251 250
251void
252void pkt_queue::put (net_packet *p) 252pkt_queue::put (net_packet *p)
253{ 253{
254 ev_tstamp now = ev_now (); 254 ev_tstamp now = ev_now ();
255 255
256 // start expiry timer 256 // start expiry timer
257 if (empty ()) 257 if (empty ())
… …
266 queue[i].tstamp = now; 266 queue[i].tstamp = now;
267 267
268 i = ni; 268 i = ni;
269} 269}
270 270
271net_packet *pkt_queue::get () 271net_packet *
272pkt_queue::get ()
272{ 273{
273 if (empty ()) 274 if (empty ())
274 return 0; 275 return 0;
275 276
276 net_packet *p = queue[j].pkt; 277 net_packet *p = queue[j].pkt;
… …
300 301
301 bool can (const sockinfo &si) { return can((u32)si.host); } 302 bool can (const sockinfo &si) { return can((u32)si.host); }
302 bool can (u32 host); 303 bool can (u32 host);
303}; 304};
304 305
305net_rate_limiter auth_rate_limiter, reset_rate_limiter; 306static net_rate_limiter auth_rate_limiter, reset_rate_limiter;
306 307
308bool
307bool net_rate_limiter::can (u32 host) 309net_rate_limiter::can (u32 host)
308{ 310{
309 iterator i; 311 iterator i;
310 312
311 for (i = begin (); i != end (); ) 313 for (i = begin (); i != end (); )
312 if (i->host == host) 314 if (i->host == host)
… …
357 } 359 }
358} 360}
359 361
360///////////////////////////////////////////////////////////////////////////// 362/////////////////////////////////////////////////////////////////////////////
361 363
362unsigned char hmac_packet::hmac_digest[EVP_MAX_MD_SIZE]; 364void
363
364void hmac_packet::hmac_gen (crypto_ctx *ctx) 365hmac_packet::hmac_gen (crypto_ctx *ctx, u8 *hmac_digest)
365{ 366{
366 unsigned int xlen; 367 ctx->hctx.init ();
367 368 ctx->hctx.add (((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet));
368 HMAC_CTX *hctx = &ctx->hctx; 369 ctx->hctx.digest (hmac_digest);
369
370 HMAC_Init_ex (hctx, 0, 0, 0, 0);
371 HMAC_Update (hctx, ((unsigned char *) this) + sizeof (hmac_packet),
372 len - sizeof (hmac_packet));
373 HMAC_Final (hctx, (unsigned char *) &hmac_digest, &xlen);
374} 370}
375 371
376void 372void
377hmac_packet::hmac_set (crypto_ctx *ctx) 373hmac_packet::hmac_set (crypto_ctx *ctx)
378{ 374{
379 hmac_gen (ctx); 375 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
380 376 hmac_gen (ctx, hmac_digest);
381 memcpy (hmac, hmac_digest, HMACLENGTH); 377 memcpy (hmac, hmac_digest, HMACLENGTH);
382} 378}
383 379
384bool 380bool
385hmac_packet::hmac_chk (crypto_ctx *ctx) 381hmac_packet::hmac_chk (crypto_ctx *ctx)
386{ 382{
387 hmac_gen (ctx); 383 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
388 384 hmac_gen (ctx, hmac_digest);
389 return !memcmp (hmac, hmac_digest, HMACLENGTH); 385 return slow_memeq (hmac, hmac_digest, HMACLENGTH);
390} 386}
391 387
388void
392void vpn_packet::set_hdr (ptype type_, unsigned int dst) 389vpn_packet::set_hdr (ptype type_, unsigned int dst)
393{ 390{
394 type = type_; 391 type = type_;
395 392
396 int src = THISNODE->id; 393 int src = THISNODE->id;
397 394
… …
399 srcdst = ((src >> 8) << 4) | (dst >> 8); 396 srcdst = ((src >> 8) << 4) | (dst >> 8);
400 dst1 = dst; 397 dst1 = dst;
401} 398}
402 399
403#define MAXVPNDATA (MAX_MTU - 6 - 6) 400#define MAXVPNDATA (MAX_MTU - 6 - 6)
404#define DATAHDR (sizeof (u32) + RAND_SIZE)
405 401
406struct 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
407 { 412 {
408 u8 data[MAXVPNDATA + DATAHDR]; // seqno 413 // the distance from beginning of packet to data member
409 414 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 }; 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}
419 439
420void 440void
421vpndata_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)
422{ 442{
423 EVP_CIPHER_CTX *cctx = &conn->octx->cctx; 443 EVP_CIPHER_CTX *cctx = conn->octx->cctx;
424 int outl = 0, outl2; 444 int outl = 0, outl2;
425 ptype type = PT_DATA_UNCOMPRESSED; 445 ptype type = PT_DATA_UNCOMPRESSED;
426 446
427#if ENABLE_COMPRESSION 447#if ENABLE_COMPRESSION
428 u8 cdata[MAX_MTU]; 448 u8 cdata[MAX_MTU];
429 449
430 if (conn->features & FEATURE_COMPRESSION) 450 if (conn->features & FEATURE_COMPRESSION)
431 { 451 {
452 static LZF_STATE lzf_state;
432 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);
433 454
434 if (cl) 455 if (cl)
435 { 456 {
436 type = PT_DATA_COMPRESSED; 457 type = PT_DATA_COMPRESSED;
437 d = cdata; 458 d = cdata;
… …
441 d[1] = cl; 462 d[1] = cl;
442 } 463 }
443 } 464 }
444#endif 465#endif
445 466
467 ctr = htonl (seqno);
468
446 require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0)); 469 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
459 470
460 require (EVP_EncryptUpdate (cctx, 471 require (EVP_EncryptUpdate (cctx,
461 (unsigned char *) data + outl, &outl2, 472 (unsigned char *)data + outl, &outl2,
462 (unsigned char *) &datahdr, DATAHDR)); 473 (unsigned char *)d, l));
463 outl += outl2; 474 outl += outl2;
464 475
465 require (EVP_EncryptUpdate (cctx, 476 // it seems this is a nop for us, but we do it anyways
466 (unsigned char *) data + outl, &outl2, 477 require (EVP_EncryptFinal_ex (cctx, (unsigned char *)data + outl, &outl2));
467 (unsigned char *) d, l));
468 outl += outl2; 478 outl += outl2;
469 479
470 require (EVP_EncryptFinal_ex (cctx, (unsigned char *) data + outl, &outl2));
471 outl += outl2;
472
473 len = outl + data_hdr_size (); 480 len = data_hdr_size () + outl;
474 481
475 set_hdr (type, dst); 482 set_hdr (type, dst);
476 483
477 hmac_set (conn->octx); 484 hmac_set (conn->octx);
478} 485}
479 486
480tap_packet * 487tap_packet *
481vpndata_packet::unpack (connection *conn, u32 &seqno) 488vpndata_packet::unpack (connection *conn, u32 &seqno)
482{ 489{
483 EVP_CIPHER_CTX *cctx = &conn->ictx->cctx; 490 EVP_CIPHER_CTX *cctx = conn->ictx->cctx;
484 int outl = 0, outl2; 491 int outl = 0, outl2;
485 tap_packet *p = new tap_packet; 492 tap_packet *p = new tap_packet;
486 u8 *d; 493 u8 *d;
487 u32 l = len - data_hdr_size ();
488 494
495 seqno = ntohl (ctr);
496
489 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, 0)); 497 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, expand_iv (ctr)));
490 498
491#if ENABLE_COMPRESSION 499#if ENABLE_COMPRESSION
492 u8 cdata[MAX_MTU]; 500 u8 cdata[MAX_MTU];
493 501
494 if (type == PT_DATA_COMPRESSED) 502 if (type == PT_DATA_COMPRESSED)
495 d = cdata; 503 d = cdata;
496 else 504 else
497#endif 505#endif
498 d = &(*p)[6 + 6 - DATAHDR]; 506 d = &(*p)[6 + 6];
499 507
500 /* this overwrites part of the src mac, but we fix that later */ 508 // this can overwrite the len/dst/src fields
501 require (EVP_DecryptUpdate (cctx, 509 require (EVP_DecryptUpdate (cctx,
502 d, &outl2, 510 d, &outl2,
503 (unsigned char *)&data, len - data_hdr_size ())); 511 (unsigned char *)&data, len - data_hdr_size ()));
504 outl += outl2; 512 outl += outl2;
505 513
514 // it seems this is a nop for us, but we do it anyways
506 require (EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2)); 515 require (EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2));
507 outl += outl2; 516 outl += outl2;
508 517
509 seqno = ntohl (*(u32 *)(d + RAND_SIZE));
510
511 id2mac (dst () ? dst() : THISNODE->id, p->dst); 518 id2mac (dst () ? dst() : THISNODE->id, p->dst);
512 id2mac (src (), p->src); 519 id2mac (src (), p->src);
513 520
514#if ENABLE_COMPRESSION 521#if ENABLE_COMPRESSION
515 if (type == PT_DATA_COMPRESSED) 522 if (type == PT_DATA_COMPRESSED)
516 { 523 {
517 u32 cl = (d[DATAHDR] << 8) | d[DATAHDR + 1]; 524 u32 cl = (d[0] << 8) | d[1];
518 525
519 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,
520 &(*p)[6 + 6], MAX_MTU) 527 &(*p)[6 + 6], MAX_MTU)
521 + 6 + 6; 528 + 6 + 6;
522 } 529 }
523 else 530 else
524 p->len = outl + (6 + 6 - DATAHDR); 531 p->len = outl + (6 + 6);
525#endif 532#endif
526 533
527 return p; 534 return p;
528} 535}
529 536
… …
536 } 543 }
537}; 544};
538 545
539struct config_packet : vpn_packet 546struct config_packet : vpn_packet
540{ 547{
541 // actually, hmaclen cannot be checked because the hmac 548 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; 549 u8 prot_major, prot_minor, randsize;
545 u8 flags, challengelen, features, pad3; 550 u8 flags, features, pad6, pad7, pad8;
546 u32 cipher_nid, digest_nid, hmac_nid; 551 u32 cipher_nid, mac_nid, auth_nid;
547 552
548 void setup (ptype type, int dst); 553 void setup (ptype type, int dst);
549 bool chk_config () const; 554 bool chk_config (const conf_node *conf, const sockinfo &rsi) const;
550 555
551 static u8 get_features () 556 static u8 get_features ()
552 { 557 {
553 u8 f = 0; 558 u8 f = 0;
554#if ENABLE_COMPRESSION 559#if ENABLE_COMPRESSION
… …
562#endif 567#endif
563 return f; 568 return f;
564 } 569 }
565}; 570};
566 571
572void
567void config_packet::setup (ptype type, int dst) 573config_packet::setup (ptype type, int dst)
568{ 574{
569 prot_major = PROTOCOL_MAJOR; 575 prot_major = PROTOCOL_MAJOR;
570 prot_minor = PROTOCOL_MINOR; 576 prot_minor = PROTOCOL_MINOR;
571 randsize = RAND_SIZE;
572 hmaclen = HMACLENGTH;
573 flags = 0; 577 flags = 0;
574 challengelen = sizeof (rsachallenge);
575 features = get_features (); 578 features = get_features ();
576 579
580 strncpy ((char *)serial, conf.serial, sizeof (serial));
581
577 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER)); 582 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ()));
578 digest_nid = htonl (EVP_MD_type (RSA_HASH));
579 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 ()));
580 585
581 len = sizeof (*this) - sizeof (net_packet); 586 len = sizeof (*this) - sizeof (net_packet);
582 set_hdr (type, dst); 587 set_hdr (type, dst);
583} 588}
584 589
585bool config_packet::chk_config () const 590bool
591config_packet::chk_config (const conf_node *conf, const sockinfo &rsi) const
586{ 592{
587 if (prot_major != PROTOCOL_MAJOR) 593 if (prot_major != PROTOCOL_MAJOR)
588 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)"),
589 else if (randsize != RAND_SIZE) 595 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))) 596 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)); 597 slog (L_WARN, _("%s(%s): cipher algo mismatch (remote %x <=> local %x)"),
597 else if (digest_nid != htonl (EVP_MD_type (RSA_HASH))) 598 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))) 599 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)); 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 ()));
601 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)
602 return true; 613 return true;
614 }
603 615
604 return false; 616 return false;
605} 617}
606 618
607struct auth_req_packet : config_packet 619struct auth_req_packet : config_packet // UNPROTECTED
608{ 620{
609 char magic[8]; 621 char magic[8];
610 u8 initiate; // false if this is just an automatic reply 622 u8 initiate; // false if this is just an automatic reply
611 u8 protocols; // supported protocols (will be patched on forward) 623 u8 protocols; // supported protocols (will be patched on forward)
612 u8 pad2, pad3; 624 u8 pad2, pad3;
613 rsaid id; 625 auth_encr encr;
614 rsaencrdata encr;
615 626
616 auth_req_packet (int dst, bool initiate_, u8 protocols_) 627 auth_req_packet (int dst, bool initiate_, u8 protocols_)
617 { 628 {
618 config_packet::setup (PT_AUTH_REQ, dst); 629 config_packet::setup (PT_AUTH_REQ, dst);
619 strncpy (magic, MAGIC_OLD, 8); 630 memcpy (magic, MAGIC, 8);
620 initiate = !!initiate_; 631 initiate = !!initiate_;
621 protocols = protocols_; 632 protocols = protocols_;
622 633
623 len = sizeof (*this) - sizeof (net_packet); 634 len = sizeof (*this) - sizeof (net_packet);
624 } 635 }
625}; 636};
626 637
627struct auth_res_packet : config_packet 638struct auth_res_packet : vpn_packet // UNPROTECTED
628{ 639{
629 rsaid id;
630 u8 pad1, pad2, pad3;
631 u8 response_len; // encrypted length
632 rsaresponse response; 640 auth_response response;
633 641
634 auth_res_packet (int dst) 642 auth_res_packet (int dst)
635 { 643 {
636 config_packet::setup (PT_AUTH_RES, dst); 644 set_hdr (PT_AUTH_RES, dst);
637 645
638 len = sizeof (*this) - sizeof (net_packet); 646 len = sizeof (*this) - sizeof (net_packet);
639 } 647 }
640}; 648};
641 649
… …
671}; 679};
672 680
673///////////////////////////////////////////////////////////////////////////// 681/////////////////////////////////////////////////////////////////////////////
674 682
675void 683void
676connection::connection_established () 684connection::connection_established (const sockinfo &rsi)
677{ 685{
678 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;
679 688
680 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."));
681 { 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
682 // make sure rekeying timeouts are slightly asymmetric 710 // make sure rekeying timeouts are slightly asymmetric
683 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);
684 rekey.start (rekey_interval, rekey_interval); 712 rekey.start (rekey_interval, rekey_interval);
713
714 hmac_error = 0.;
715
685 keepalive.start (::conf.keepalive); 716 keepalive.start (::conf.keepalive);
686 717
687 // send queued packets 718 // send queued packets
688 if (ictx && octx)
689 {
690 while (tap_packet *p = (tap_packet *)data_queue.get ()) 719 while (tap_packet *p = (tap_packet *)data_queue.get ())
691 { 720 {
692 if (p->len) send_data_packet (p); 721 if (p->len) send_data_packet (p);
693 delete p; 722 delete p;
694 } 723 }
695 724
696 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) 725 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
697 { 726 {
698 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY); 727 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
699 delete p; 728 delete p;
700 } 729 }
701 }
702 730
703 vpn->connection_established (this); 731 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} 732}
713 733
714void 734void
715connection::reset_si () 735connection::reset_si ()
716{ 736{
… …
721 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename); 741 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename);
722 protocol = 0; 742 protocol = 0;
723 } 743 }
724 744
725 si.set (conf, protocol); 745 si.set (conf, protocol);
726
727 is_direct = si.valid ();
728} 746}
729 747
730// ensure sockinfo is valid, forward if necessary 748// ensure sockinfo is valid, forward if necessary
731const sockinfo & 749const sockinfo &
732connection::forward_si (const sockinfo &si) const 750connection::forward_si (const sockinfo &si) const
… …
751 769
752void 770void
753connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) 771connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
754{ 772{
755 if (!vpn->send_vpn_packet (pkt, si, tos)) 773 if (!vpn->send_vpn_packet (pkt, si, tos))
756 reset_connection (); 774 reset_connection ("packet send error");
757} 775}
758 776
759void 777void
760connection::send_ping (const sockinfo &si, u8 pong) 778connection::send_ping (const sockinfo &si, u8 pong)
761{ 779{
762 ping_packet *pkt = new ping_packet; 780 ping_packet *pkt = new ping_packet;
763 781
764 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);
765 783
766 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);
767
768 send_vpn_packet (pkt, si, IPTOS_LOWDELAY); 785 send_vpn_packet (pkt, si, IPTOS_LOWDELAY);
769 786
770 delete pkt; 787 delete pkt;
771} 788}
772 789
… …
787void 804void
788connection::send_auth_request (const sockinfo &si, bool initiate) 805connection::send_auth_request (const sockinfo &si, bool initiate)
789{ 806{
790 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);
791 808
792 rsachallenge chg; 809 generate_auth_data ();
793 rsa_cache.gen (pkt->id, chg);
794 rsa_encrypt (conf->rsa_key, chg, pkt->encr); 810 auth_encrypt (conf->rsa_key, snd_auth, pkt->encr);
795 811
796 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);
797
798 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
799 814
800 delete pkt; 815 delete pkt;
801} 816}
802 817
803void 818void
804connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg) 819connection::send_auth_response (const sockinfo &si)
805{ 820{
806 auth_res_packet *pkt = new auth_res_packet (conf->id); 821 auth_res_packet *pkt = new auth_res_packet (conf->id);
807 822
808 pkt->id = id; 823 memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof rcv_ecdh_b);
809 824 auth_hash (rcv_auth, rcv_ecdh_b, pkt->response.mac);
810 rsa_hash (id, chg, pkt->response);
811
812 pkt->hmac_set (octx);
813 825
814 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);
815
816 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
817 828
818 delete pkt; 829 delete pkt;
819} 830}
820 831
821void 832void
822connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols) 833connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols)
823{ 834{
824 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,
825 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi); 836 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi,
837 conf->protocols);
826 838
827 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);
828 840
829 r->hmac_set (octx); 841 r->hmac_set (octx);
830 send_vpn_packet (r, si); 842 send_vpn_packet (r, si);
… …
833} 845}
834 846
835inline void 847inline void
836connection::establish_connection_cb (ev::timer &w, int revents) 848connection::establish_connection_cb (ev::timer &w, int revents)
837{ 849{
838 if (!ictx 850 if (!(ictx && octx)
839 && conf != THISNODE 851 && conf != THISNODE
840 && connectmode != conf_node::C_NEVER 852 && connectmode != conf_node::C_NEVER
841 && connectmode != conf_node::C_DISABLED 853 && connectmode != conf_node::C_DISABLED
842 && !w.is_active ()) 854 && !w.is_active ())
843 { 855 {
844 // 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
845 // 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.
846 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 ())
847 { 859 {
848 reset_connection (); 860 reset_connection ("no demand");
849 return; 861 return;
850 } 862 }
851 863
852 last_establish_attempt = ev_now (); 864 last_establish_attempt = ev_now ();
853 865
… …
855 ? (retry_cnt & 3) + 1 867 ? (retry_cnt & 3) + 1
856 : 1 << (retry_cnt >> 2)); 868 : 1 << (retry_cnt >> 2));
857 869
858 reset_si (); 870 reset_si ();
859 871
860 bool slow = si.prot & PROT_SLOW; 872 bool slow = (si.prot & PROT_SLOW) || (conf->low_power || THISNODE->low_power);
861 873
862 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf)) 874 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf))
863 { 875 {
864 /*TODO*/ /* start the timer so we don't recurse endlessly */ 876 /*TODO*/ /* start the timer so we don't recurse endlessly */
865 w.start (1); 877 w.start (1);
… …
875 887
876 slow = slow || (dsi.prot & PROT_SLOW); 888 slow = slow || (dsi.prot & PROT_SLOW);
877 889
878 if (dsi.valid () && auth_rate_limiter.can (dsi)) 890 if (dsi.valid () && auth_rate_limiter.can (dsi))
879 { 891 {
880 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))
881 send_auth_request (dsi, true); 896 send_auth_request (dsi, true);
882 else 897 else
883 send_ping (dsi, 0); 898 send_ping (dsi, 0);
884 } 899 }
885 } 900 }
886 901
887 retry_int *= slow ? 8. : 0.9; 902 retry_int *= slow ? 4. : 0.9;
888 903
889 if (retry_int < conf->max_retry) 904 if (retry_int < conf->max_retry)
890 retry_cnt++; 905 retry_cnt++;
891 else 906 else
892 retry_int = conf->max_retry; 907 retry_int = conf->max_retry;
… …
894 w.start (retry_int); 909 w.start (retry_int);
895 } 910 }
896} 911}
897 912
898void 913void
899connection::reset_connection () 914connection::reset_connection (const char *reason)
900{ 915{
901 if (ictx && octx) 916 if (ictx && octx)
902 { 917 {
903 slog (L_INFO, _("%s(%s): connection lost"), 918 slog (L_INFO, _("%s(%s): connection lost (%s)"),
904 conf->nodename, (const char *)si); 919 conf->nodename, (const char *)si, reason);
905 920
906 if (::conf.script_node_down) 921 if (::conf.script_node_down)
907 { 922 {
908 run_script_cb *cb = new run_script_cb; 923 run_script_cb *cb = new run_script_cb;
909 cb->set<connection, &connection::script_node_down> (this); 924 cb->set<connection, &connection::script_node_down> (this);
… …
911 } 926 }
912 } 927 }
913 928
914 delete ictx; ictx = 0; 929 delete ictx; ictx = 0;
915 delete octx; octx = 0; 930 delete octx; octx = 0;
916#if ENABLE_DNS
917 dnsv4_reset_connection ();
918#endif
919 931
920 si.host = 0; 932 si.host = 0;
933
934 have_snd_auth = false;
935 have_rcv_auth = false;
936 auth_expire = 0.;
921 937
922 last_activity = 0.; 938 last_activity = 0.;
923 //last_si_change = 0.; 939 //last_si_change = 0.;
924 retry_cnt = 0; 940 retry_cnt = 0;
925 941
… …
932connection::shutdown () 948connection::shutdown ()
933{ 949{
934 if (ictx && octx) 950 if (ictx && octx)
935 send_reset (si); 951 send_reset (si);
936 952
937 reset_connection (); 953 reset_connection ("shutdown");
938} 954}
939 955
940// poor-man's rekeying 956// poor-man's rekeying
941inline void 957inline void
942connection::rekey_cb (ev::timer &w, int revents) 958connection::rekey_cb (ev::timer &w, int revents)
943{ 959{
944 reset_connection (); 960 reset_connection ("rekeying");
945 establish_connection (); 961 establish_connection ();
946} 962}
947 963
948void 964void
949connection::send_data_packet (tap_packet *pkt) 965connection::send_data_packet (tap_packet *pkt)
… …
966 982
967void 983void
968connection::post_inject_queue () 984connection::post_inject_queue ()
969{ 985{
970 // 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)
971 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
972 establish_connection.stop (); 988 establish_connection.stop ();
973 989
974 establish_connection (); 990 establish_connection ();
975} 991}
976 992
… …
984 data_queue.put (new tap_packet (*pkt)); 1000 data_queue.put (new tap_packet (*pkt));
985 post_inject_queue (); 1001 post_inject_queue ();
986 } 1002 }
987} 1003}
988 1004
1005void
989void connection::inject_vpn_packet (vpn_packet *pkt, int tos) 1006connection::inject_vpn_packet (vpn_packet *pkt, int tos)
990{ 1007{
991 if (ictx && octx) 1008 if (ictx && octx)
992 send_vpn_packet (pkt, si, tos); 1009 send_vpn_packet (pkt, si, tos);
993 else 1010 else
994 { 1011 {
… …
1000void 1017void
1001connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi) 1018connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
1002{ 1019{
1003 last_activity = ev_now (); 1020 last_activity = ev_now ();
1004 1021
1005 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.",
1006 conf->nodename, pkt->typ (), pkt->src (), pkt->dst ()); 1023 conf->nodename, pkt->typ (), pkt->src (), pkt->dst ());
1007 1024
1008 if (connectmode == conf_node::C_DISABLED) 1025 if (connectmode == conf_node::C_DISABLED)
1009 return; 1026 return;
1010 1027
… …
1035 // about our desire for communication. 1052 // about our desire for communication.
1036 establish_connection (); 1053 establish_connection ();
1037 break; 1054 break;
1038 1055
1039 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)
1040 { 1060 {
1041 reset_connection (); 1061 reset_connection ("remote reset");
1042 1062
1043 config_packet *p = (config_packet *) pkt; 1063 config_packet *p = (config_packet *) pkt;
1044 1064
1045 if (!p->chk_config ()) 1065 if (p->chk_config (conf, rsi) && connectmode == conf_node::C_ALWAYS)
1046 {
1047 slog (L_WARN, _("%s(%s): protocol mismatch, disabling node."),
1048 conf->nodename, (const char *)rsi);
1049 connectmode = conf_node::C_DISABLED;
1050 }
1051 else if (connectmode == conf_node::C_ALWAYS)
1052 establish_connection (); 1066 establish_connection ();
1053 } 1067 }
1068
1054 break; 1069 break;
1055 1070
1056 case vpn_packet::PT_AUTH_REQ: 1071 case vpn_packet::PT_AUTH_REQ:
1057 if (auth_rate_limiter.can (rsi)) 1072 if (auth_rate_limiter.can (rsi))
1058 { 1073 {
1059 auth_req_packet *p = (auth_req_packet *) pkt; 1074 auth_req_packet *p = (auth_req_packet *)pkt;
1060 1075
1061 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);
1062 1079
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 }
1063 if (p->chk_config () 1085 else if (p->chk_config (conf, rsi))
1064 && (!strncmp (p->magic, MAGIC_OLD, 8) || !strncmp (p->magic, MAGIC, 8)))
1065 { 1086 {
1066 if (p->prot_minor != PROTOCOL_MINOR) 1087 if (p->prot_minor != PROTOCOL_MINOR)
1067 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."),
1068 conf->nodename, (const char *)rsi, 1089 conf->nodename, (const char *)rsi,
1069 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 1090 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1070 1091
1071 if (p->initiate) 1092 if (p->initiate)
1093 {
1072 send_auth_request (rsi, false); 1094 send_auth_request (rsi, false);
1073 1095
1074 rsachallenge k; 1096 if (ictx && octx)
1097 reset_connection ("reconnect");
1098 }
1075 1099
1100 auth_data auth;
1101
1076 if (!rsa_decrypt (::conf.rsa_key, p->encr, k)) 1102 if (!auth_decrypt (::conf.rsa_key, p->encr, auth))
1077 { 1103 {
1078 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?"),
1079 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));
1080 break;
1081 } 1106 }
1082 else 1107 else
1083 { 1108 {
1084 delete octx; 1109 bool chg = !have_rcv_auth || !slow_memeq (&rcv_auth, &auth, sizeof auth);
1085 1110
1086 octx = new crypto_ctx (k, 1); 1111 rcv_auth = auth;
1087 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; 1112 have_rcv_auth = true;
1088 1113
1114 send_auth_response (rsi);
1115
1116 if (chg)
1117 {
1089 conf->protocols = p->protocols; 1118 conf->protocols = p->protocols;
1090 features = p->features & config_packet::get_features (); 1119 features = p->features & config_packet::get_features ();
1091 1120
1092 send_auth_response (rsi, p->id, k);
1093
1094 connection_established (); 1121 connection_established (rsi);
1095
1096 break; 1122 }
1097 } 1123 }
1124
1125 break;
1098 } 1126 }
1099 else
1100 slog (L_WARN, _("%s(%s): protocol mismatch."),
1101 conf->nodename, (const char *)rsi);
1102 1127
1103 send_reset (rsi); 1128 send_reset (rsi);
1104 } 1129 }
1105 1130
1106 break; 1131 break;
… …
1109 { 1134 {
1110 auth_res_packet *p = (auth_res_packet *)pkt; 1135 auth_res_packet *p = (auth_res_packet *)pkt;
1111 1136
1112 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename); 1137 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename);
1113 1138
1114 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))
1115 { 1143 {
1116 if (p->prot_minor != PROTOCOL_MINOR)
1117 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1118 conf->nodename, (const char *)rsi,
1119 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1120
1121 rsachallenge chg;
1122
1123 if (!rsa_cache.find (p->id, chg))
1124 {
1125 slog (L_ERR, _("%s(%s): unrequested auth response, ignoring."), 1144 slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."),
1126 conf->nodename, (const char *)rsi); 1145 conf->nodename, (const char *)rsi);
1127 break;
1128 } 1146 }
1129 else 1147 else if (!have_snd_auth)
1130 { 1148 {
1131 crypto_ctx *cctx = new crypto_ctx (chg, 0); 1149 memcpy (snd_ecdh_b, p->response.ecdh, sizeof snd_ecdh_b);
1132 1150
1133 if (!p->hmac_chk (cctx)) 1151 have_snd_auth = true;
1134 {
1135 slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n"
1136 "could be an attack, or just corruption or a synchronization error."),
1137 conf->nodename, (const char *)rsi);
1138 break;
1139 }
1140 else
1141 {
1142 rsaresponse h;
1143
1144 rsa_hash (p->id, chg, h);
1145
1146 if (!memcmp ((u8 *)&h, (u8 *)p->response, sizeof h))
1147 {
1148 prot_minor = p->prot_minor;
1149
1150 delete ictx; ictx = cctx;
1151
1152 iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
1153
1154 si = rsi;
1155 protocol = rsi.prot;
1156
1157 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
1158 conf->nodename, (const char *)rsi,
1159 is_direct ? "direct" : "forwarded",
1160 p->prot_major, p->prot_minor);
1161
1162 connection_established (); 1152 connection_established (rsi);
1163
1164 if (::conf.script_node_up)
1165 {
1166 run_script_cb *cb = new run_script_cb;
1167 cb->set<connection, &connection::script_node_up> (this);
1168 run_script_queued (cb, _("node-up command execution failed, continuing."));
1169 }
1170
1171 break;
1172 }
1173 else
1174 slog (L_ERR, _("%s(%s): sent and received challenge do not match."),
1175 conf->nodename, (const char *)rsi);
1176 }
1177
1178 delete cctx;
1179 }
1180 } 1153 }
1181 } 1154 }
1182
1183 send_reset (rsi);
1184 break; 1155 break;
1185 1156
1186 case vpn_packet::PT_DATA_COMPRESSED: 1157 case vpn_packet::PT_DATA_COMPRESSED:
1187#if !ENABLE_COMPRESSION 1158#if !ENABLE_COMPRESSION
1188 send_reset (rsi); 1159 send_reset (rsi);
… …
1194 if (ictx && octx) 1165 if (ictx && octx)
1195 { 1166 {
1196 vpndata_packet *p = (vpndata_packet *)pkt; 1167 vpndata_packet *p = (vpndata_packet *)pkt;
1197 1168
1198 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 {
1199 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"
1200 "could be an attack, or just corruption or a synchronization error."), 1185 "could be an attack, or just corruption or a synchronization error."),
1201 conf->nodename, (const char *)rsi); 1186 conf->nodename, (const char *)rsi);
1187 // reset
1188 }
1189 }
1202 else 1190 else
1203 { 1191 {
1204 u32 seqno; 1192 u32 seqno;
1205 tap_packet *d = p->unpack (this, seqno); 1193 tap_packet *d = p->unpack (this, seqno);
1206 int seqclass = iseqno.seqno_classify (seqno); 1194 int seqclass = iseqno.seqno_classify (seqno);
1195
1196 hmac_error = 0;
1207 1197
1208 if (seqclass == 0) // ok 1198 if (seqclass == 0) // ok
1209 { 1199 {
1210 vpn->tap->send (d); 1200 vpn->tap->send (d);
1211 1201
… …
1261 if (p->id > 0 && p->id <= vpn->conns.size ()) 1251 if (p->id > 0 && p->id <= vpn->conns.size ())
1262 { 1252 {
1263 connection *c = vpn->conns[p->id - 1]; 1253 connection *c = vpn->conns[p->id - 1];
1264 conf->protocols = p->protocols; 1254 conf->protocols = p->protocols;
1265 1255
1266 slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s) [%d]", 1256 slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s,p%02x) [%d]",
1267 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);
1268 1260
1269 if (c->ictx && c->octx) 1261 if (c->ictx && c->octx)
1270 { 1262 {
1271 // send connect_info packets to both sides, in case one is 1263 // send connect_info packets to both sides, in case one is
1272 // behind a nat firewall (or both ;) 1264 // behind a nat firewall (or both ;)
… …
1295 1287
1296 c->conf->protocols = p->protocols; 1288 c->conf->protocols = p->protocols;
1297 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));
1298 p->si.upgrade_protocol (protocol, c->conf); 1290 p->si.upgrade_protocol (protocol, c->conf);
1299 1291
1300 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,
1301 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),
1302 (const char *)p->si, !c->ictx && !c->octx); 1299 !c->ictx && !c->octx);
1303 1300
1304 const sockinfo &dsi = forward_si (p->si); 1301 const sockinfo &dsi = forward_si (p->si);
1305 1302
1306 if (dsi.valid ()) 1303 if (dsi.valid ())
1307 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);
1308 } 1309 }
1309 else 1310 else
1310 slog (L_WARN, 1311 slog (L_WARN,
1311 _("received authenticated connection request from unknown node #%d, config file mismatch?"), 1312 _("received authenticated connection request from unknown node #%d, config file mismatch?"),
1312 p->id); 1313 p->id);
… …
1321} 1322}
1322 1323
1323inline void 1324inline void
1324connection::keepalive_cb (ev::timer &w, int revents) 1325connection::keepalive_cb (ev::timer &w, int revents)
1325{ 1326{
1326 if (ev_now () >= last_activity + ::conf.keepalive + 15) 1327 ev_tstamp when = last_activity + ::conf.keepalive - ev::now ();
1328
1329 if (when >= 0)
1330 w.start (when);
1331 else if (when < -15)
1327 { 1332 {
1328 reset_connection (); 1333 reset_connection ("keepalive overdue");
1329 establish_connection (); 1334 establish_connection ();
1330 } 1335 }
1331 else if (ev_now () < last_activity + ::conf.keepalive)
1332 w.start (last_activity + ::conf.keepalive - ev::now ());
1333 else if (conf->connectmode != conf_node::C_ONDEMAND 1336 else if (conf->connectmode != conf_node::C_ONDEMAND
1334 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1337 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1335 { 1338 {
1339 w.start (3);
1336 send_ping (si); 1340 send_ping (si);
1337 w.start (3);
1338 } 1341 }
1339 else if (ev_now () < last_activity + ::conf.keepalive + 10) 1342 else if (when >= -10)
1340 // hold ondemand connections implicitly a few seconds longer 1343 // hold ondemand connections implicitly a few seconds longer
1341 // should delete octx, though, or something like that ;) 1344 // should delete octx, though, or something like that ;)
1342 w.start (last_activity + ::conf.keepalive + 10 - ev::now ()); 1345 w.start (when + 10);
1343 else 1346 else
1344 reset_connection (); 1347 reset_connection ("keepalive timeout");
1345} 1348}
1346 1349
1350void
1347void connection::send_connect_request (int id) 1351connection::send_connect_request (int id)
1348{ 1352{
1349 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);
1350 1354
1351 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s)", 1355 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s,p%02x)",
1352 conf->nodename, vpn->conns[id - 1]->conf->nodename); 1356 conf->nodename, vpn->conns[id - 1]->conf->nodename,
1357 THISNODE->protocols);
1353 p->hmac_set (octx); 1358 p->hmac_set (octx);
1354 send_vpn_packet (p, si); 1359 send_vpn_packet (p, si);
1355 1360
1356 delete p; 1361 delete p;
1357} 1362}
1358 1363
1364void
1359void connection::script_init_env (const char *ext) 1365connection::script_init_env (const char *ext)
1360{ 1366{
1361 char *env; 1367 char *env;
1362 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);
1363 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env); 1369 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env);
1364 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext, 1370 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext,
1365 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8, 1371 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8,
1366 conf->id & 0xff); putenv (env); 1372 conf->id & 0xff); putenv (env);
1367} 1373}
1368 1374
1375void
1369void connection::script_init_connect_env () 1376connection::script_init_connect_env ()
1370{ 1377{
1371 vpn->script_init_env (); 1378 vpn->script_init_env ();
1372 1379
1373 char *env; 1380 char *env;
1374 asprintf (&env, "DESTID=%d", conf->id); putenv (env); 1381 asprintf (&env, "DESTID=%d", conf->id); putenv (env);
… …
1439 establish_connection.set<connection, &connection::establish_connection_cb> (this); 1446 establish_connection.set<connection, &connection::establish_connection_cb> (this);
1440 1447
1441 last_establish_attempt = 0.; 1448 last_establish_attempt = 0.;
1442 octx = ictx = 0; 1449 octx = ictx = 0;
1443 1450
1444 if (!conf->protocols) // make sure some protocol is enabled
1445 conf->protocols = PROT_UDPv4;
1446
1447 connectmode = conf->connectmode; 1451 connectmode = conf->connectmode;
1448 1452
1449 // queue a dummy packet to force an initial connection attempt 1453 // queue a dummy packet to force an initial connection attempt
1450 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED) 1454 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED)
1451 vpn_queue.put (new net_packet); 1455 vpn_queue.put (new net_packet);
1452 1456
1453 reset_connection (); 1457 reset_connection ("startup");
1454} 1458}
1455 1459
1456connection::~connection () 1460connection::~connection ()
1457{ 1461{
1458 shutdown (); 1462 shutdown ();
1459} 1463}
1460 1464
1465void
1461void connection_init () 1466connection_init ()
1462{ 1467{
1463 auth_rate_limiter.clear (); 1468 auth_rate_limiter.clear ();
1464 reset_rate_limiter.clear (); 1469 reset_rate_limiter.clear ();
1465} 1470}
1466 1471

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