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Comparing gvpe/src/connection.C (file contents):
Revision 1.82 by pcg, Fri Aug 15 18:35:24 2008 UTC vs.
Revision 1.115 by root, Thu Jun 30 16:31:00 2016 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
57#define ULTRA_FAST 1 56#define ULTRA_FAST 1
58#define HLOG 15 57#define HLOG 15
59#include "lzf/lzf.h" 58#include "lzf/lzf.h"
60#include "lzf/lzf_c.c" 59#include "lzf/lzf_c.c"
… …
63////////////////////////////////////////////////////////////////////////////// 62//////////////////////////////////////////////////////////////////////////////
64 63
65static std::queue< std::pair<run_script_cb *, const char *> > rs_queue; 64static std::queue< std::pair<run_script_cb *, const char *> > rs_queue;
66static ev::child rs_child_ev; 65static ev::child rs_child_ev;
67 66
67namespace
68{
68void // c++ requires external linkage here, apparently :( 69 void // c++ requires external linkage here, apparently :(
69rs_child_cb (ev::child &w, int revents) 70 rs_child_cb (ev::child &w, int revents)
70{ 71 {
71 w.stop (); 72 w.stop ();
72 73
73 if (rs_queue.empty ()) 74 if (rs_queue.empty ())
74 return; 75 return;
75 76
76 pid_t pid = run_script (*rs_queue.front ().first, false); 77 pid_t pid = run_script (*rs_queue.front ().first, false);
77 if (pid) 78 if (pid)
78 { 79 {
79 w.set (pid); 80 w.set (pid);
80 w.start (); 81 w.start ();
81 } 82 }
82 else 83 else
83 slog (L_WARN, rs_queue.front ().second); 84 slog (L_WARN, rs_queue.front ().second);
84 85
85 delete rs_queue.front ().first; 86 delete rs_queue.front ().first;
86 rs_queue.pop (); 87 rs_queue.pop ();
87} 88 }
89};
88 90
89// despite the fancy name, this is quite a hack 91// despite the fancy name, this is quite a hack
90static void 92static void
91run_script_queued (run_script_cb *cb, const char *warnmsg) 93run_script_queued (run_script_cb *cb, const char *warnmsg)
92{ 94{
… …
101 103
102////////////////////////////////////////////////////////////////////////////// 104//////////////////////////////////////////////////////////////////////////////
103 105
104struct crypto_ctx 106struct crypto_ctx
105{ 107{
106 EVP_CIPHER_CTX cctx; 108 cipher cctx;
107 HMAC_CTX hctx; 109 hmac hctx;
108 110
109 crypto_ctx (const rsachallenge &challenge, int enc); 111 crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc);
110 ~crypto_ctx (); 112 ~crypto_ctx ();
111}; 113};
112 114
113crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc) 115crypto_ctx::crypto_ctx (const auth_data &auth1, const auth_data &auth2, const ecdh_key &a, const ecdh_key &b, int enc)
114{ 116{
117 ecdh_key s;
118
119 curve25519_combine (a, b, s);
120
121 {
122 u8 mac_key[MAC_KEYSIZE];
123 static const unsigned char mac_info[] = "gvpe mac key";
124
125 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
126 kdf.extract (auth1.rsa.mac_key, sizeof (auth1.rsa.mac_key));
127 kdf.extract (s, sizeof (s));
128 kdf.extract_done (HKDF_PRF_HASH ());
129 kdf.expand (mac_key, sizeof (mac_key), mac_info, sizeof (mac_info));
130
131 hctx.init (mac_key, MAC_KEYSIZE, MAC_DIGEST ());
132 }
133
134 {
135 u8 cipher_key[CIPHER_KEYSIZE];
136 static const unsigned char cipher_info[] = "gvpe cipher key";
137
138 hkdf kdf (auth2.rsa.hkdf_salt, sizeof (auth2.rsa.hkdf_salt), HKDF_XTR_HASH ());
139 kdf.extract (auth1.rsa.cipher_key, sizeof (auth1.rsa.cipher_key));
140 kdf.extract (s, sizeof (s));
141 kdf.extract_done (HKDF_PRF_HASH ());
142 kdf.expand (cipher_key, sizeof (cipher_key), cipher_info, sizeof (cipher_info));
143
115 EVP_CIPHER_CTX_init (&cctx); 144 EVP_CIPHER_CTX_init (cctx);
116 require (EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc)); 145 require (EVP_CipherInit_ex (cctx, CIPHER (), 0, cipher_key, 0, enc));
117 HMAC_CTX_init (&hctx); 146 }
118 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
119} 147}
120 148
121crypto_ctx::~crypto_ctx () 149crypto_ctx::~crypto_ctx ()
122{ 150{
123 require (EVP_CIPHER_CTX_cleanup (&cctx)); 151 require (EVP_CIPHER_CTX_cleanup (cctx));
124 HMAC_CTX_cleanup (&hctx); 152}
153
154static inline void
155auth_encrypt (RSA *key, const auth_data &auth, auth_encr &encr)
156{
157 if (RSA_public_encrypt (sizeof (auth.rsa),
158 (unsigned char *)&auth.rsa, (unsigned char *)&encr.rsa,
159 key, RSA_PKCS1_OAEP_PADDING) < 0)
160 fatal ("RSA_public_encrypt error");
161
162 memcpy (&encr.ecdh, &auth.ecdh, sizeof (encr.ecdh));
163}
164
165static inline bool
166auth_decrypt (RSA *key, const auth_encr &encr, auth_data &auth)
167{
168 u8 rsa_decrypt[RSA_KEYLEN];
169
170 if (RSA_private_decrypt (sizeof (encr.rsa),
171 (const unsigned char *)&encr.rsa, (unsigned char *)rsa_decrypt,
172 key, RSA_PKCS1_OAEP_PADDING) != sizeof (auth.rsa))
173 return 0;
174
175 memcpy (&auth.rsa, rsa_decrypt, sizeof (auth.rsa));
176 memcpy (&auth.ecdh, &encr.ecdh, sizeof (auth.ecdh));
177
178 return 1;
125} 179}
126 180
127static void 181static void
128rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h) 182auth_hash (const auth_data &auth, const ecdh_key &b, auth_mac &mac)
129{ 183{
130 EVP_MD_CTX ctx; 184 hkdf kdf (b, sizeof b, AUTH_DIGEST ()); // use response ecdh b as salt
131 185 kdf.extract (&auth.rsa, sizeof (auth.rsa));
132 EVP_MD_CTX_init (&ctx); 186 kdf.extract_done ();
133 require (EVP_DigestInit (&ctx, RSA_HASH)); 187 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} 188}
139 189
140struct rsa_entry 190void
191connection::generate_auth_data ()
141{ 192{
142 tstamp expire; 193 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 { 194 {
155 if (!memcmp (&id, &i->id, sizeof id) && i->expire > ev_now ()) 195 // request data
156 { 196 rand_fill (snd_auth.rsa);
157 memcpy (&chg, &i->chg, sizeof chg); 197 curve25519_generate (snd_ecdh_a, snd_auth.ecdh);
158 198
159 erase (i); 199 // eventual response data
160 return true; 200 curve25519_generate (rcv_ecdh_a, rcv_ecdh_b);
161 }
162 } 201 }
163 202
164 if (!cleaner.is_active ()) 203 // 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; 204 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} 205}
208 206
209////////////////////////////////////////////////////////////////////////////// 207//////////////////////////////////////////////////////////////////////////////
210 208
211pkt_queue::pkt_queue (double max_ttl, int max_queue) 209pkt_queue::pkt_queue (double max_ttl, int max_queue)
… …
225 delete p; 223 delete p;
226 224
227 delete [] queue; 225 delete [] queue;
228} 226}
229 227
228void
230void pkt_queue::expire_cb (ev::timer &w, int revents) 229pkt_queue::expire_cb (ev::timer &w, int revents)
231{ 230{
232 ev_tstamp expire = ev_now () - max_ttl; 231 ev_tstamp expire = ev_now () - max_ttl;
233 232
234 for (;;) 233 for (;;)
235 { 234 {
… …
246 245
247 delete get (); 246 delete get ();
248 } 247 }
249} 248}
250 249
250void
251void pkt_queue::put (net_packet *p) 251pkt_queue::put (net_packet *p)
252{ 252{
253 ev_tstamp now = ev_now (); 253 ev_tstamp now = ev_now ();
254 254
255 // start expiry timer 255 // start expiry timer
256 if (empty ()) 256 if (empty ())
… …
265 queue[i].tstamp = now; 265 queue[i].tstamp = now;
266 266
267 i = ni; 267 i = ni;
268} 268}
269 269
270net_packet *pkt_queue::get () 270net_packet *
271pkt_queue::get ()
271{ 272{
272 if (empty ()) 273 if (empty ())
273 return 0; 274 return 0;
274 275
275 net_packet *p = queue[j].pkt; 276 net_packet *p = queue[j].pkt;
… …
299 300
300 bool can (const sockinfo &si) { return can((u32)si.host); } 301 bool can (const sockinfo &si) { return can((u32)si.host); }
301 bool can (u32 host); 302 bool can (u32 host);
302}; 303};
303 304
304net_rate_limiter auth_rate_limiter, reset_rate_limiter; 305static net_rate_limiter auth_rate_limiter, reset_rate_limiter;
305 306
307bool
306bool net_rate_limiter::can (u32 host) 308net_rate_limiter::can (u32 host)
307{ 309{
308 iterator i; 310 iterator i;
309 311
310 for (i = begin (); i != end (); ) 312 for (i = begin (); i != end (); )
311 if (i->host == host) 313 if (i->host == host)
… …
356 } 358 }
357} 359}
358 360
359///////////////////////////////////////////////////////////////////////////// 361/////////////////////////////////////////////////////////////////////////////
360 362
361unsigned char hmac_packet::hmac_digest[EVP_MAX_MD_SIZE]; 363void
362
363void hmac_packet::hmac_gen (crypto_ctx *ctx) 364hmac_packet::hmac_gen (crypto_ctx *ctx, u8 *hmac_digest)
364{ 365{
365 unsigned int xlen; 366 ctx->hctx.init ();
366 367 ctx->hctx.add (((unsigned char *) this) + sizeof (hmac_packet), len - sizeof (hmac_packet));
367 HMAC_CTX *hctx = &ctx->hctx; 368 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} 369}
374 370
375void 371void
376hmac_packet::hmac_set (crypto_ctx *ctx) 372hmac_packet::hmac_set (crypto_ctx *ctx)
377{ 373{
378 hmac_gen (ctx); 374 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
379 375 hmac_gen (ctx, hmac_digest);
380 memcpy (hmac, hmac_digest, HMACLENGTH); 376 memcpy (hmac, hmac_digest, HMACLENGTH);
381} 377}
382 378
383bool 379bool
384hmac_packet::hmac_chk (crypto_ctx *ctx) 380hmac_packet::hmac_chk (crypto_ctx *ctx)
385{ 381{
386 hmac_gen (ctx); 382 unsigned char hmac_digest[EVP_MAX_MD_SIZE];
387 383 hmac_gen (ctx, hmac_digest);
388 return !memcmp (hmac, hmac_digest, HMACLENGTH); 384 return slow_memeq (hmac, hmac_digest, HMACLENGTH);
389} 385}
390 386
387void
391void vpn_packet::set_hdr (ptype type_, unsigned int dst) 388vpn_packet::set_hdr (ptype type_, unsigned int dst)
392{ 389{
393 type = type_; 390 type = type_;
394 391
395 int src = THISNODE->id; 392 int src = THISNODE->id;
396 393
… …
398 srcdst = ((src >> 8) << 4) | (dst >> 8); 395 srcdst = ((src >> 8) << 4) | (dst >> 8);
399 dst1 = dst; 396 dst1 = dst;
400} 397}
401 398
402#define MAXVPNDATA (MAX_MTU - 6 - 6) 399#define MAXVPNDATA (MAX_MTU - 6 - 6)
403#define DATAHDR (sizeof (u32) + RAND_SIZE)
404 400
405struct vpndata_packet : vpn_packet 401struct vpndata_packet : vpn_packet
402{
403 u32 ctr; // seqno
404 u8 data[MAXVPNDATA];
405
406 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
407 tap_packet *unpack (connection *conn, u32 &seqno);
408
409private:
410 const u32 data_hdr_size () const
406 { 411 {
407 u8 data[MAXVPNDATA + DATAHDR]; // seqno 412 // the distance from beginning of packet to data member
408 413 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 }; 414 }
415};
416
417// expands packet counter (unlike seqno, in network byte order) to counter mode IV
418static unsigned char *
419expand_iv (u32 ctr)
420{
421 static u32 iv[IV_SIZE (CIPHER) / 4];
422
423 require (sizeof (iv) == 4 * 4);
424 require (IV_SIZE (CIPHER) % 4 == 0);
425
426 iv[0] =
427 iv[1] =
428 iv[2] = ctr;
429
430 // I would reuse ctr here to to avoid potential endianness issues,
431 // but it seems openssl wraps around. While this would be still ok,
432 // and I don't even know if its true, let's play safe and initialise
433 // to 0.
434 iv[3] = 0;
435
436 return (unsigned char *)iv;
437}
418 438
419void 439void
420vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno) 440vpndata_packet::setup (connection *conn, int dst, u8 *d, u32 l, u32 seqno)
421{ 441{
422 EVP_CIPHER_CTX *cctx = &conn->octx->cctx; 442 EVP_CIPHER_CTX *cctx = conn->octx->cctx;
423 int outl = 0, outl2; 443 int outl = 0, outl2;
424 ptype type = PT_DATA_UNCOMPRESSED; 444 ptype type = PT_DATA_UNCOMPRESSED;
425 445
426#if ENABLE_COMPRESSION 446#if ENABLE_COMPRESSION
427 u8 cdata[MAX_MTU]; 447 u8 cdata[MAX_MTU];
428 448
429 if (conn->features & ENABLE_COMPRESSION) 449 if (conn->features & FEATURE_COMPRESSION)
430 { 450 {
431 u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7); 451 u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7);
432 452
433 if (cl) 453 if (cl)
434 { 454 {
… …
440 d[1] = cl; 460 d[1] = cl;
441 } 461 }
442 } 462 }
443#endif 463#endif
444 464
465 ctr = htonl (seqno);
466
445 require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0)); 467 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
458 468
459 require (EVP_EncryptUpdate (cctx, 469 require (EVP_EncryptUpdate (cctx,
460 (unsigned char *) data + outl, &outl2, 470 (unsigned char *)data + outl, &outl2,
461 (unsigned char *) &datahdr, DATAHDR)); 471 (unsigned char *)d, l));
462 outl += outl2; 472 outl += outl2;
463 473
464 require (EVP_EncryptUpdate (cctx, 474 // it seems this is a nop for us, but we do it anyways
465 (unsigned char *) data + outl, &outl2, 475 require (EVP_EncryptFinal_ex (cctx, (unsigned char *)data + outl, &outl2));
466 (unsigned char *) d, l));
467 outl += outl2; 476 outl += outl2;
468 477
469 require (EVP_EncryptFinal_ex (cctx, (unsigned char *) data + outl, &outl2));
470 outl += outl2;
471
472 len = outl + data_hdr_size (); 478 len = data_hdr_size () + outl;
473 479
474 set_hdr (type, dst); 480 set_hdr (type, dst);
475 481
476 hmac_set (conn->octx); 482 hmac_set (conn->octx);
477} 483}
478 484
479tap_packet * 485tap_packet *
480vpndata_packet::unpack (connection *conn, u32 &seqno) 486vpndata_packet::unpack (connection *conn, u32 &seqno)
481{ 487{
482 EVP_CIPHER_CTX *cctx = &conn->ictx->cctx; 488 EVP_CIPHER_CTX *cctx = conn->ictx->cctx;
483 int outl = 0, outl2; 489 int outl = 0, outl2;
484 tap_packet *p = new tap_packet; 490 tap_packet *p = new tap_packet;
485 u8 *d; 491 u8 *d;
486 u32 l = len - data_hdr_size ();
487 492
493 seqno = ntohl (ctr);
494
488 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, 0)); 495 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, expand_iv (ctr)));
489 496
490#if ENABLE_COMPRESSION 497#if ENABLE_COMPRESSION
491 u8 cdata[MAX_MTU]; 498 u8 cdata[MAX_MTU];
492 499
493 if (type == PT_DATA_COMPRESSED) 500 if (type == PT_DATA_COMPRESSED)
494 d = cdata; 501 d = cdata;
495 else 502 else
496#endif 503#endif
497 d = &(*p)[6 + 6 - DATAHDR]; 504 d = &(*p)[6 + 6];
498 505
499 /* this overwrites part of the src mac, but we fix that later */ 506 // this can overwrite the len/dst/src fields
500 require (EVP_DecryptUpdate (cctx, 507 require (EVP_DecryptUpdate (cctx,
501 d, &outl2, 508 d, &outl2,
502 (unsigned char *)&data, len - data_hdr_size ())); 509 (unsigned char *)&data, len - data_hdr_size ()));
503 outl += outl2; 510 outl += outl2;
504 511
512 // it seems this is a nop for us, but we do it anyways
505 require (EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2)); 513 require (EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2));
506 outl += outl2; 514 outl += outl2;
507 515
508 seqno = ntohl (*(u32 *)(d + RAND_SIZE));
509
510 id2mac (dst () ? dst() : THISNODE->id, p->dst); 516 id2mac (dst () ? dst() : THISNODE->id, p->dst);
511 id2mac (src (), p->src); 517 id2mac (src (), p->src);
512 518
513#if ENABLE_COMPRESSION 519#if ENABLE_COMPRESSION
514 if (type == PT_DATA_COMPRESSED) 520 if (type == PT_DATA_COMPRESSED)
515 { 521 {
516 u32 cl = (d[DATAHDR] << 8) | d[DATAHDR + 1]; 522 u32 cl = (d[0] << 8) | d[1];
517 523
518 p->len = lzf_decompress (d + DATAHDR + 2, cl < MAX_MTU ? cl : 0, 524 p->len = lzf_decompress (d + 2, cl < MAX_MTU - 2 ? cl : 0,
519 &(*p)[6 + 6], MAX_MTU) 525 &(*p)[6 + 6], MAX_MTU)
520 + 6 + 6; 526 + 6 + 6;
521 } 527 }
522 else 528 else
523 p->len = outl + (6 + 6 - DATAHDR); 529 p->len = outl + (6 + 6);
524#endif 530#endif
525 531
526 return p; 532 return p;
527} 533}
528 534
… …
535 } 541 }
536}; 542};
537 543
538struct config_packet : vpn_packet 544struct config_packet : vpn_packet
539{ 545{
540 // actually, hmaclen cannot be checked because the hmac 546 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; 547 u8 prot_major, prot_minor, randsize;
544 u8 flags, challengelen, features, pad3; 548 u8 flags, features, pad6, pad7, pad8;
545 u32 cipher_nid, digest_nid, hmac_nid; 549 u32 cipher_nid, mac_nid, auth_nid;
546 550
547 void setup (ptype type, int dst); 551 void setup (ptype type, int dst);
548 bool chk_config () const; 552 bool chk_config (const conf_node *conf, const sockinfo &rsi) const;
549 553
550 static u8 get_features () 554 static u8 get_features ()
551 { 555 {
552 u8 f = 0; 556 u8 f = 0;
553#if ENABLE_COMPRESSION 557#if ENABLE_COMPRESSION
… …
561#endif 565#endif
562 return f; 566 return f;
563 } 567 }
564}; 568};
565 569
570void
566void config_packet::setup (ptype type, int dst) 571config_packet::setup (ptype type, int dst)
567{ 572{
568 prot_major = PROTOCOL_MAJOR; 573 prot_major = PROTOCOL_MAJOR;
569 prot_minor = PROTOCOL_MINOR; 574 prot_minor = PROTOCOL_MINOR;
570 randsize = RAND_SIZE;
571 hmaclen = HMACLENGTH;
572 flags = 0; 575 flags = 0;
573 challengelen = sizeof (rsachallenge);
574 features = get_features (); 576 features = get_features ();
575 577
578 strncpy ((char *)serial, conf.serial, sizeof (serial));
579
576 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER)); 580 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER ()));
577 digest_nid = htonl (EVP_MD_type (RSA_HASH));
578 hmac_nid = htonl (EVP_MD_type (DIGEST)); 581 mac_nid = htonl (EVP_MD_type (MAC_DIGEST ()));
582 auth_nid = htonl (EVP_MD_type (AUTH_DIGEST ()));
579 583
580 len = sizeof (*this) - sizeof (net_packet); 584 len = sizeof (*this) - sizeof (net_packet);
581 set_hdr (type, dst); 585 set_hdr (type, dst);
582} 586}
583 587
584bool config_packet::chk_config () const 588bool
589config_packet::chk_config (const conf_node *conf, const sockinfo &rsi) const
585{ 590{
586 if (prot_major != PROTOCOL_MAJOR) 591 if (prot_major != PROTOCOL_MAJOR)
587 slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR); 592 slog (L_WARN, _("%s(%s): major version mismatch (remote %d <=> local %d)"),
588 else if (randsize != RAND_SIZE) 593 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))) 594 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)); 595 slog (L_WARN, _("%s(%s): cipher algo mismatch (remote %x <=> local %x)"),
596 else if (digest_nid != htonl (EVP_MD_type (RSA_HASH))) 596 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))) 597 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)); 598 slog (L_WARN, _("%s(%s): mac algo mismatch (remote %x <=> local %x)"),
599 conf->nodename, (const char *)rsi, ntohl (mac_nid), EVP_MD_type (MAC_DIGEST ()));
600 else if (auth_nid != htonl (EVP_MD_type (AUTH_DIGEST ())))
601 slog (L_WARN, _("%s(%s): auth algo mismatch (remote %x <=> local %x)"),
602 conf->nodename, (const char *)rsi, ntohl (auth_nid), EVP_MD_type (AUTH_DIGEST ()));
600 else 603 else
604 {
605 int cmp = memcmp (serial, ::conf.serial, sizeof (serial));
606
607 if (cmp > 0)
608 slog (L_WARN, _("%s(%s): remote serial newer than local serial - outdated config?"),
609 conf->nodename, (const char *)rsi);
610 else if (cmp == 0)
601 return true; 611 return true;
612 }
602 613
603 return false; 614 return false;
604} 615}
605 616
606struct auth_req_packet : config_packet 617struct auth_req_packet : config_packet // UNPROTECTED
607{ 618{
608 char magic[8]; 619 char magic[8];
609 u8 initiate; // false if this is just an automatic reply 620 u8 initiate; // false if this is just an automatic reply
610 u8 protocols; // supported protocols (will be patched on forward) 621 u8 protocols; // supported protocols (will be patched on forward)
611 u8 pad2, pad3; 622 u8 pad2, pad3;
612 rsaid id; 623 auth_encr encr;
613 rsaencrdata encr;
614 624
615 auth_req_packet (int dst, bool initiate_, u8 protocols_) 625 auth_req_packet (int dst, bool initiate_, u8 protocols_)
616 { 626 {
617 config_packet::setup (PT_AUTH_REQ, dst); 627 config_packet::setup (PT_AUTH_REQ, dst);
618 strncpy (magic, MAGIC, 8); 628 memcpy (magic, MAGIC, 8);
619 initiate = !!initiate_; 629 initiate = !!initiate_;
620 protocols = protocols_; 630 protocols = protocols_;
621 631
622 len = sizeof (*this) - sizeof (net_packet); 632 len = sizeof (*this) - sizeof (net_packet);
623 } 633 }
624}; 634};
625 635
626struct auth_res_packet : config_packet 636struct auth_res_packet : vpn_packet // UNPROTECTED
627{ 637{
628 rsaid id;
629 u8 pad1, pad2, pad3;
630 u8 response_len; // encrypted length
631 rsaresponse response; 638 auth_response response;
632 639
633 auth_res_packet (int dst) 640 auth_res_packet (int dst)
634 { 641 {
635 config_packet::setup (PT_AUTH_RES, dst); 642 set_hdr (PT_AUTH_RES, dst);
636 643
637 len = sizeof (*this) - sizeof (net_packet); 644 len = sizeof (*this) - sizeof (net_packet);
638 } 645 }
639}; 646};
640 647
… …
670}; 677};
671 678
672///////////////////////////////////////////////////////////////////////////// 679/////////////////////////////////////////////////////////////////////////////
673 680
674void 681void
675connection::connection_established () 682connection::connection_established (const sockinfo &rsi)
676{ 683{
677 slog (L_NOISE, _("%s: possible connection establish (ictx %d, octx %d)"), conf->nodename, !!ictx, !!octx); 684 if (!have_snd_auth || !have_rcv_auth)
685 return;
678 686
679 if (ictx && octx) 687 si = rsi;
688 protocol = rsi.prot;
689
690 slog (L_INFO, _("%s(%s): connection established (%s), protocol version %d.%d."),
691 conf->nodename, (const char *)rsi,
692 vpn->can_direct (THISNODE, conf) ? "direct" : "forwarded",
693 PROTOCOL_MAJOR, prot_minor);
694
695 if (::conf.script_node_up)
696 {
697 run_script_cb *cb = new run_script_cb;
698 cb->set<connection, &connection::script_node_up> (this);
699 run_script_queued (cb, _("node-up command execution failed, continuing."));
680 { 700 }
701
702 delete ictx; ictx = new crypto_ctx (rcv_auth, snd_auth, rcv_ecdh_a, rcv_auth.ecdh, 0);
703 iseqno.reset (ntohl (rcv_auth.rsa.seqno) & 0x7fffffff);
704
705 delete octx; octx = new crypto_ctx (snd_auth, rcv_auth, snd_ecdh_a, snd_ecdh_b , 1);
706 oseqno = ntohl (snd_auth.rsa.seqno) & 0x7fffffff;
707
681 // make sure rekeying timeouts are slightly asymmetric 708 // make sure rekeying timeouts are slightly asymmetric
682 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0); 709 ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0);
683 rekey.start (rekey_interval, rekey_interval); 710 rekey.start (rekey_interval, rekey_interval);
711
712 hmac_error = 0.;
713
684 keepalive.start (::conf.keepalive); 714 keepalive.start (::conf.keepalive);
685 715
686 // send queued packets 716 // send queued packets
687 if (ictx && octx)
688 {
689 while (tap_packet *p = (tap_packet *)data_queue.get ()) 717 while (tap_packet *p = (tap_packet *)data_queue.get ())
690 { 718 {
691 if (p->len) send_data_packet (p); 719 if (p->len) send_data_packet (p);
692 delete p; 720 delete p;
693 } 721 }
694 722
695 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) 723 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
696 { 724 {
697 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY); 725 if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
698 delete p; 726 delete p;
699 } 727 }
700 }
701 728
702 vpn->connection_established (this); 729 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} 730}
712 731
713void 732void
714connection::reset_si () 733connection::reset_si ()
715{ 734{
… …
720 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename); 739 slog (L_TRACE, _("%s: direct connection denied by config."), conf->nodename);
721 protocol = 0; 740 protocol = 0;
722 } 741 }
723 742
724 si.set (conf, protocol); 743 si.set (conf, protocol);
725
726 is_direct = si.valid ();
727} 744}
728 745
729// ensure sockinfo is valid, forward if necessary 746// ensure sockinfo is valid, forward if necessary
730const sockinfo & 747const sockinfo &
731connection::forward_si (const sockinfo &si) const 748connection::forward_si (const sockinfo &si) const
… …
750 767
751void 768void
752connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) 769connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
753{ 770{
754 if (!vpn->send_vpn_packet (pkt, si, tos)) 771 if (!vpn->send_vpn_packet (pkt, si, tos))
755 reset_connection (); 772 reset_connection ("packet send error");
756} 773}
757 774
758void 775void
759connection::send_ping (const sockinfo &si, u8 pong) 776connection::send_ping (const sockinfo &si, u8 pong)
760{ 777{
761 ping_packet *pkt = new ping_packet; 778 ping_packet *pkt = new ping_packet;
762 779
763 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING); 780 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING);
764 781
765 slog (L_TRACE, "%s << %s [%s]", conf->nodename, pong ? "PT_PONG" : "PT_PING", (const char *)si); 782 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); 783 send_vpn_packet (pkt, si, IPTOS_LOWDELAY);
768 784
769 delete pkt; 785 delete pkt;
770} 786}
771 787
… …
786void 802void
787connection::send_auth_request (const sockinfo &si, bool initiate) 803connection::send_auth_request (const sockinfo &si, bool initiate)
788{ 804{
789 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols); 805 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols);
790 806
791 rsachallenge chg; 807 generate_auth_data ();
792 rsa_cache.gen (pkt->id, chg);
793 rsa_encrypt (conf->rsa_key, chg, pkt->encr); 808 auth_encrypt (conf->rsa_key, snd_auth, pkt->encr);
794 809
795 slog (L_TRACE, "%s << PT_AUTH_REQ [%s]", conf->nodename, (const char *)si); 810 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 811 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly
798 812
799 delete pkt; 813 delete pkt;
800} 814}
801 815
802void 816void
803connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg) 817connection::send_auth_response (const sockinfo &si)
804{ 818{
805 auth_res_packet *pkt = new auth_res_packet (conf->id); 819 auth_res_packet *pkt = new auth_res_packet (conf->id);
806 820
807 pkt->id = id; 821 memcpy (pkt->response.ecdh, rcv_ecdh_b, sizeof rcv_ecdh_b);
808 822 auth_hash (rcv_auth, rcv_ecdh_b, pkt->response.mac);
809 rsa_hash (id, chg, pkt->response);
810
811 pkt->hmac_set (octx);
812 823
813 slog (L_TRACE, "%s << PT_AUTH_RES [%s]", conf->nodename, (const char *)si); 824 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 825 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly
816 826
817 delete pkt; 827 delete pkt;
818} 828}
819 829
820void 830void
821connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols) 831connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols)
822{ 832{
823 slog (L_TRACE, "%s << PT_CONNECT_INFO(%s,%s)", conf->nodename, 833 slog (L_TRACE, "%s << PT_CONNECT_INFO(%s,%s,p%02x)", conf->nodename,
824 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi); 834 vpn->conns[rid - 1]->conf->nodename, (const char *)rsi,
835 conf->protocols);
825 836
826 connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols); 837 connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols);
827 838
828 r->hmac_set (octx); 839 r->hmac_set (octx);
829 send_vpn_packet (r, si); 840 send_vpn_packet (r, si);
… …
832} 843}
833 844
834inline void 845inline void
835connection::establish_connection_cb (ev::timer &w, int revents) 846connection::establish_connection_cb (ev::timer &w, int revents)
836{ 847{
837 if (!ictx 848 if (!(ictx && octx)
838 && conf != THISNODE 849 && conf != THISNODE
839 && connectmode != conf_node::C_NEVER 850 && connectmode != conf_node::C_NEVER
840 && connectmode != conf_node::C_DISABLED 851 && connectmode != conf_node::C_DISABLED
841 && !w.is_active ()) 852 && !w.is_active ())
842 { 853 {
843 // a bit hacky, if ondemand, and packets are no longer queued, then reset the connection 854 // 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. 855 // 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 ()) 856 if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ())
846 { 857 {
847 reset_connection (); 858 reset_connection ("no demand");
848 return; 859 return;
849 } 860 }
850 861
851 last_establish_attempt = ev_now (); 862 last_establish_attempt = ev_now ();
852 863
… …
854 ? (retry_cnt & 3) + 1 865 ? (retry_cnt & 3) + 1
855 : 1 << (retry_cnt >> 2)); 866 : 1 << (retry_cnt >> 2));
856 867
857 reset_si (); 868 reset_si ();
858 869
859 bool slow = si.prot & PROT_SLOW; 870 bool slow = (si.prot & PROT_SLOW) || (conf->low_power || THISNODE->low_power);
860 871
861 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf)) 872 if (si.prot && !si.host && vpn->can_direct (THISNODE, conf))
862 { 873 {
863 /*TODO*/ /* start the timer so we don't recurse endlessly */ 874 /*TODO*/ /* start the timer so we don't recurse endlessly */
864 w.start (1); 875 w.start (1);
… …
874 885
875 slow = slow || (dsi.prot & PROT_SLOW); 886 slow = slow || (dsi.prot & PROT_SLOW);
876 887
877 if (dsi.valid () && auth_rate_limiter.can (dsi)) 888 if (dsi.valid () && auth_rate_limiter.can (dsi))
878 { 889 {
879 if (retry_cnt < 4) 890 // use ping after the first few retries
891 // TODO: on rekeys, the other node might not interpret ping correctly,
892 // TODO: as it will still have a valid connection
893 if (retry_cnt < 4 && (!conf->low_power || THISNODE->low_power))
880 send_auth_request (dsi, true); 894 send_auth_request (dsi, true);
881 else 895 else
882 send_ping (dsi, 0); 896 send_ping (dsi, 0);
883 } 897 }
884 } 898 }
885 899
886 retry_int *= slow ? 8. : 0.9; 900 retry_int *= slow ? 4. : 0.9;
887 901
888 if (retry_int < conf->max_retry) 902 if (retry_int < conf->max_retry)
889 retry_cnt++; 903 retry_cnt++;
890 else 904 else
891 retry_int = conf->max_retry; 905 retry_int = conf->max_retry;
… …
893 w.start (retry_int); 907 w.start (retry_int);
894 } 908 }
895} 909}
896 910
897void 911void
898connection::reset_connection () 912connection::reset_connection (const char *reason)
899{ 913{
900 if (ictx && octx) 914 if (ictx && octx)
901 { 915 {
902 slog (L_INFO, _("%s(%s): connection lost"), 916 slog (L_INFO, _("%s(%s): connection lost (%s)"),
903 conf->nodename, (const char *)si); 917 conf->nodename, (const char *)si, reason);
904 918
905 if (::conf.script_node_down) 919 if (::conf.script_node_down)
906 { 920 {
907 run_script_cb *cb = new run_script_cb; 921 run_script_cb *cb = new run_script_cb;
908 cb->set<connection, &connection::script_node_down> (this); 922 cb->set<connection, &connection::script_node_down> (this);
… …
910 } 924 }
911 } 925 }
912 926
913 delete ictx; ictx = 0; 927 delete ictx; ictx = 0;
914 delete octx; octx = 0; 928 delete octx; octx = 0;
915#if ENABLE_DNS
916 dnsv4_reset_connection ();
917#endif
918 929
919 si.host = 0; 930 si.host = 0;
931
932 have_snd_auth = false;
933 have_rcv_auth = false;
934 auth_expire = 0.;
920 935
921 last_activity = 0.; 936 last_activity = 0.;
922 //last_si_change = 0.; 937 //last_si_change = 0.;
923 retry_cnt = 0; 938 retry_cnt = 0;
924 939
… …
931connection::shutdown () 946connection::shutdown ()
932{ 947{
933 if (ictx && octx) 948 if (ictx && octx)
934 send_reset (si); 949 send_reset (si);
935 950
936 reset_connection (); 951 reset_connection ("shutdown");
937} 952}
938 953
939// poor-man's rekeying 954// poor-man's rekeying
940inline void 955inline void
941connection::rekey_cb (ev::timer &w, int revents) 956connection::rekey_cb (ev::timer &w, int revents)
942{ 957{
943 reset_connection (); 958 reset_connection ("rekeying");
944 establish_connection (); 959 establish_connection ();
945} 960}
946 961
947void 962void
948connection::send_data_packet (tap_packet *pkt) 963connection::send_data_packet (tap_packet *pkt)
… …
965 980
966void 981void
967connection::post_inject_queue () 982connection::post_inject_queue ()
968{ 983{
969 // force a connection every now and when when packets are sent (max 1/s) 984 // force a connection every now and when when packets are sent (max 1/s)
970 if (ev_now () - last_establish_attempt >= 0.95) // arbitrary 985 if (ev_now () - last_establish_attempt >= (conf->low_power || THISNODE->low_power ? 2.95 : 0.95)) // arbitrary
971 establish_connection.stop (); 986 establish_connection.stop ();
972 987
973 establish_connection (); 988 establish_connection ();
974} 989}
975 990
… …
983 data_queue.put (new tap_packet (*pkt)); 998 data_queue.put (new tap_packet (*pkt));
984 post_inject_queue (); 999 post_inject_queue ();
985 } 1000 }
986} 1001}
987 1002
1003void
988void connection::inject_vpn_packet (vpn_packet *pkt, int tos) 1004connection::inject_vpn_packet (vpn_packet *pkt, int tos)
989{ 1005{
990 if (ictx && octx) 1006 if (ictx && octx)
991 send_vpn_packet (pkt, si, tos); 1007 send_vpn_packet (pkt, si, tos);
992 else 1008 else
993 { 1009 {
… …
999void 1015void
1000connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi) 1016connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
1001{ 1017{
1002 last_activity = ev_now (); 1018 last_activity = ev_now ();
1003 1019
1004 slog (L_NOISE, "%s >> received packet type %d from %d to %d.", 1020 slog (L_NOISE, "%s >> received packet type %d from %d to %d.",
1005 conf->nodename, pkt->typ (), pkt->src (), pkt->dst ()); 1021 conf->nodename, pkt->typ (), pkt->src (), pkt->dst ());
1006 1022
1007 if (connectmode == conf_node::C_DISABLED) 1023 if (connectmode == conf_node::C_DISABLED)
1008 return; 1024 return;
1009 1025
… …
1019 { 1035 {
1020 if (auth_rate_limiter.can (rsi)) 1036 if (auth_rate_limiter.can (rsi))
1021 send_auth_request (rsi, true); 1037 send_auth_request (rsi, true);
1022 } 1038 }
1023 else 1039 else
1024 // we would love to change thre socket address here, but ping's aren't 1040 // we would love to change the socket address here, but ping's aren't
1025 // authenticated, so we best ignore it. 1041 // authenticated, so we best ignore it.
1026 send_ping (rsi, 1); // pong 1042 send_ping (rsi, 1); // pong
1027 1043
1028 break; 1044 break;
1029 1045
1030 case vpn_packet::PT_PONG: 1046 case vpn_packet::PT_PONG:
1031 slog (L_TRACE, "%s >> PT_PONG", conf->nodename); 1047 slog (L_TRACE, "%s >> PT_PONG", conf->nodename);
1048
1049 // a PONG might mean that the other side doesn't really know
1050 // about our desire for communication.
1051 establish_connection ();
1032 break; 1052 break;
1033 1053
1034 case vpn_packet::PT_RESET: 1054 case vpn_packet::PT_RESET:
1055 slog (L_TRACE, "%s >> PT_RESET", conf->nodename);
1056
1057 if (ictx && octx)
1035 { 1058 {
1036 reset_connection (); 1059 reset_connection ("remote reset");
1037 1060
1038 config_packet *p = (config_packet *) pkt; 1061 config_packet *p = (config_packet *) pkt;
1039 1062
1040 if (!p->chk_config ()) 1063 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 (); 1064 establish_connection ();
1048 } 1065 }
1066
1049 break; 1067 break;
1050 1068
1051 case vpn_packet::PT_AUTH_REQ: 1069 case vpn_packet::PT_AUTH_REQ:
1052 if (auth_rate_limiter.can (rsi)) 1070 if (auth_rate_limiter.can (rsi))
1053 { 1071 {
1054 auth_req_packet *p = (auth_req_packet *) pkt; 1072 auth_req_packet *p = (auth_req_packet *)pkt;
1055 1073
1056 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s)", conf->nodename, p->initiate ? "initiate" : "reply"); 1074 slog (L_TRACE, "%s >> PT_AUTH_REQ(%s,p%02x,f%02x)",
1075 conf->nodename, p->initiate ? "initiate" : "reply",
1076 p->protocols, p->features);
1057 1077
1058 if (p->chk_config () && !strncmp (p->magic, MAGIC, 8)) 1078 if (memcmp (p->magic, MAGIC, 8))
1079 {
1080 slog (L_WARN, _("%s(%s): protocol magic mismatch - stray packet?"),
1081 conf->nodename, (const char *)rsi);
1082 }
1083 else if (p->chk_config (conf, rsi))
1059 { 1084 {
1060 if (p->prot_minor != PROTOCOL_MINOR) 1085 if (p->prot_minor != PROTOCOL_MINOR)
1061 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."), 1086 slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
1062 conf->nodename, (const char *)rsi, 1087 conf->nodename, (const char *)rsi,
1063 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 1088 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
1064 1089
1065 if (p->initiate) 1090 if (p->initiate)
1091 {
1066 send_auth_request (rsi, false); 1092 send_auth_request (rsi, false);
1067 1093
1068 rsachallenge k; 1094 if (ictx && octx)
1095 reset_connection ("reconnect");
1096 }
1069 1097
1098 auth_data auth;
1099
1070 if (!rsa_decrypt (::conf.rsa_key, p->encr, k)) 1100 if (!auth_decrypt (::conf.rsa_key, p->encr, auth))
1071 { 1101 {
1072 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"), 1102 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)); 1103 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0));
1074 break;
1075 } 1104 }
1076 else 1105 else
1077 { 1106 {
1078 delete octx; 1107 bool chg = !have_rcv_auth || !slow_memeq (&rcv_auth, &auth, sizeof auth);
1079 1108
1080 octx = new crypto_ctx (k, 1); 1109 rcv_auth = auth;
1081 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; 1110 have_rcv_auth = true;
1082 1111
1112 send_auth_response (rsi);
1113
1114 if (chg)
1115 {
1083 conf->protocols = p->protocols; 1116 conf->protocols = p->protocols;
1084 features = p->features & config_packet::get_features (); 1117 features = p->features & config_packet::get_features ();
1085 1118
1086 send_auth_response (rsi, p->id, k);
1087
1088 connection_established (); 1119 connection_established (rsi);
1089
1090 break; 1120 }
1091 } 1121 }
1122
1123 break;
1092 } 1124 }
1093 else
1094 slog (L_WARN, _("%s(%s): protocol mismatch."),
1095 conf->nodename, (const char *)rsi);
1096 1125
1097 send_reset (rsi); 1126 send_reset (rsi);
1098 } 1127 }
1099 1128
1100 break; 1129 break;
… …
1103 { 1132 {
1104 auth_res_packet *p = (auth_res_packet *)pkt; 1133 auth_res_packet *p = (auth_res_packet *)pkt;
1105 1134
1106 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename); 1135 slog (L_TRACE, "%s >> PT_AUTH_RES", conf->nodename);
1107 1136
1108 if (p->chk_config ()) 1137 auth_mac local_mac;
1138 auth_hash (snd_auth, p->response.ecdh, local_mac);
1139
1140 if (!slow_memeq (&p->response.mac, local_mac, sizeof local_mac))
1109 { 1141 {
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."), 1142 slog (L_ERR, _("%s(%s): unrequested or outdated auth response, ignoring."),
1120 conf->nodename, (const char *)rsi); 1143 conf->nodename, (const char *)rsi);
1121 break;
1122 } 1144 }
1123 else 1145 else if (!have_snd_auth)
1124 { 1146 {
1125 crypto_ctx *cctx = new crypto_ctx (chg, 0); 1147 memcpy (snd_ecdh_b, p->response.ecdh, sizeof snd_ecdh_b);
1126 1148
1127 if (!p->hmac_chk (cctx)) 1149 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" : "forwarded",
1154 p->prot_major, p->prot_minor);
1155
1156 connection_established (); 1150 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 } 1151 }
1175 } 1152 }
1176
1177 send_reset (rsi);
1178 break; 1153 break;
1179 1154
1180 case vpn_packet::PT_DATA_COMPRESSED: 1155 case vpn_packet::PT_DATA_COMPRESSED:
1181#if !ENABLE_COMPRESSION 1156#if !ENABLE_COMPRESSION
1182 send_reset (rsi); 1157 send_reset (rsi);
… …
1188 if (ictx && octx) 1163 if (ictx && octx)
1189 { 1164 {
1190 vpndata_packet *p = (vpndata_packet *)pkt; 1165 vpndata_packet *p = (vpndata_packet *)pkt;
1191 1166
1192 if (!p->hmac_chk (ictx)) 1167 if (!p->hmac_chk (ictx))
1168 {
1169 // rekeying often creates temporary hmac auth floods
1170 // we assume they don't take longer than a few seconds normally,
1171 // and suppress messages and resets during that time.
1172 //TODO: should be done per source address
1173 if (!hmac_error)
1174 {
1175 hmac_error = ev_now () + 3;
1176 break;
1177 }
1178 else if (hmac_error >= ev_now ())
1179 break; // silently suppress
1180 else
1181 {
1193 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n" 1182 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
1194 "could be an attack, or just corruption or a synchronization error."), 1183 "could be an attack, or just corruption or a synchronization error."),
1195 conf->nodename, (const char *)rsi); 1184 conf->nodename, (const char *)rsi);
1185 // reset
1186 }
1187 }
1196 else 1188 else
1197 { 1189 {
1198 u32 seqno; 1190 u32 seqno;
1199 tap_packet *d = p->unpack (this, seqno); 1191 tap_packet *d = p->unpack (this, seqno);
1200 int seqclass = iseqno.seqno_classify (seqno); 1192 int seqclass = iseqno.seqno_classify (seqno);
1193
1194 hmac_error = 0;
1201 1195
1202 if (seqclass == 0) // ok 1196 if (seqclass == 0) // ok
1203 { 1197 {
1204 vpn->tap->send (d); 1198 vpn->tap->send (d);
1205 1199
… …
1210 // { 1204 // {
1211 slog (L_INFO, _("%s(%s): changing socket address to %s."), 1205 slog (L_INFO, _("%s(%s): changing socket address to %s."),
1212 conf->nodename, (const char *)si, (const char *)rsi); 1206 conf->nodename, (const char *)si, (const char *)rsi);
1213 1207
1214 si = rsi; 1208 si = rsi;
1209
1210 if (::conf.script_node_change)
1211 {
1212 run_script_cb *cb = new run_script_cb;
1213 cb->set<connection, &connection::script_node_change> (this);
1214 run_script_queued (cb, _("node-change command execution failed, continuing."));
1215 }
1216
1215 // } 1217 // }
1216 //else 1218 //else
1217 // slog (L_INFO, _("%s(%s): accepted packet from %s, not (yet) redirecting traffic."), 1219 // slog (L_INFO, _("%s(%s): accepted packet from %s, not (yet) redirecting traffic."),
1218 // conf->nodename, (const char *)si, (const char *)rsi); 1220 // conf->nodename, (const char *)si, (const char *)rsi);
1219 } 1221 }
… …
1240 break; 1242 break;
1241 1243
1242 case vpn_packet::PT_CONNECT_REQ: 1244 case vpn_packet::PT_CONNECT_REQ:
1243 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx)) 1245 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx))
1244 { 1246 {
1245 connect_req_packet *p = (connect_req_packet *) pkt; 1247 connect_req_packet *p = (connect_req_packet *)pkt;
1246 1248
1247 if (p->id > 0 && p->id <= vpn->conns.size ()) 1249 if (p->id > 0 && p->id <= vpn->conns.size ())
1248 { 1250 {
1249 connection *c = vpn->conns[p->id - 1]; 1251 connection *c = vpn->conns[p->id - 1];
1250 conf->protocols = p->protocols; 1252 conf->protocols = p->protocols;
1251 1253
1252 slog (L_TRACE, "%s >> PT_CONNECT_REQ(%s) [%d]", 1254 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); 1255 conf->nodename, vpn->conns[p->id - 1]->conf->nodename,
1256 p->protocols,
1257 c->ictx && c->octx);
1254 1258
1255 if (c->ictx && c->octx) 1259 if (c->ictx && c->octx)
1256 { 1260 {
1257 // send connect_info packets to both sides, in case one is 1261 // send connect_info packets to both sides, in case one is
1258 // behind a nat firewall (or both ;) 1262 // behind a nat firewall (or both ;)
… …
1281 1285
1282 c->conf->protocols = p->protocols; 1286 c->conf->protocols = p->protocols;
1283 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf)); 1287 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf));
1284 p->si.upgrade_protocol (protocol, c->conf); 1288 p->si.upgrade_protocol (protocol, c->conf);
1285 1289
1286 slog (L_TRACE, "%s >> PT_CONNECT_INFO(%s,%s) [%d]", 1290 slog (L_TRACE, "%s >> PT_CONNECT_INFO(%s,%s,protocols=%02x,protocol=%02x,upgradable=%02x) [%d]",
1291 conf->nodename,
1287 conf->nodename, vpn->conns[p->id - 1]->conf->nodename, 1292 vpn->conns[p->id - 1]->conf->nodename,
1293 (const char *)p->si,
1294 p->protocols,
1295 protocol,
1296 p->si.supported_protocols (c->conf),
1288 (const char *)p->si, !c->ictx && !c->octx); 1297 !c->ictx && !c->octx);
1289 1298
1290 const sockinfo &dsi = forward_si (p->si); 1299 const sockinfo &dsi = forward_si (p->si);
1291 1300
1292 if (dsi.valid ()) 1301 if (dsi.valid ())
1293 c->send_auth_request (dsi, true); 1302 c->send_auth_request (dsi, true);
1303 else
1304 slog (L_INFO, "connect info for %s received (%s), but still unable to contact.",
1305 vpn->conns[p->id - 1]->conf->nodename,
1306 (const char *)p->si);
1294 } 1307 }
1295 else 1308 else
1296 slog (L_WARN, 1309 slog (L_WARN,
1297 _("received authenticated connection request from unknown node #%d, config file mismatch?"), 1310 _("received authenticated connection request from unknown node #%d, config file mismatch?"),
1298 p->id); 1311 p->id);
… …
1307} 1320}
1308 1321
1309inline void 1322inline void
1310connection::keepalive_cb (ev::timer &w, int revents) 1323connection::keepalive_cb (ev::timer &w, int revents)
1311{ 1324{
1312 if (ev_now () >= last_activity + ::conf.keepalive + 30) 1325 ev_tstamp when = last_activity + ::conf.keepalive - ev::now ();
1326
1327 if (when >= 0)
1328 w.start (when);
1329 else if (when < -15)
1313 { 1330 {
1314 reset_connection (); 1331 reset_connection ("keepalive overdue");
1315 establish_connection (); 1332 establish_connection ();
1316 } 1333 }
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 1334 else if (conf->connectmode != conf_node::C_ONDEMAND
1320 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1335 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1321 { 1336 {
1337 w.start (3);
1322 send_ping (si); 1338 send_ping (si);
1323 w.start (5);
1324 } 1339 }
1325 else if (ev_now () < last_activity + ::conf.keepalive + 10) 1340 else if (when >= -10)
1326 // hold ondemand connections implicitly a few seconds longer 1341 // hold ondemand connections implicitly a few seconds longer
1327 // should delete octx, though, or something like that ;) 1342 // should delete octx, though, or something like that ;)
1328 w.start (last_activity + ::conf.keepalive + 10 - ev::now ()); 1343 w.start (when + 10);
1329 else 1344 else
1330 reset_connection (); 1345 reset_connection ("keepalive timeout");
1331} 1346}
1332 1347
1348void
1333void connection::send_connect_request (int id) 1349connection::send_connect_request (int id)
1334{ 1350{
1335 connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols); 1351 connect_req_packet *p = new connect_req_packet (conf->id, id, THISNODE->protocols);
1336 1352
1337 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s)", 1353 slog (L_TRACE, "%s << PT_CONNECT_REQ(%s,p%02x)",
1338 conf->nodename, vpn->conns[id - 1]->conf->nodename); 1354 conf->nodename, vpn->conns[id - 1]->conf->nodename,
1355 THISNODE->protocols);
1339 p->hmac_set (octx); 1356 p->hmac_set (octx);
1340 send_vpn_packet (p, si); 1357 send_vpn_packet (p, si);
1341 1358
1342 delete p; 1359 delete p;
1343} 1360}
1344 1361
1362void
1345void connection::script_init_env (const char *ext) 1363connection::script_init_env (const char *ext)
1346{ 1364{
1347 char *env; 1365 char *env;
1348 asprintf (&env, "IFUPDATA%s=%s", ext, conf->if_up_data); putenv (env); 1366 asprintf (&env, "IFUPDATA%s=%s", ext, conf->if_up_data); putenv (env);
1349 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env); 1367 asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env);
1350 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext, 1368 asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext,
1351 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8, 1369 0xfe, 0xfd, 0x80, 0x00, conf->id >> 8,
1352 conf->id & 0xff); putenv (env); 1370 conf->id & 0xff); putenv (env);
1353} 1371}
1354 1372
1373void
1355void connection::script_init_connect_env () 1374connection::script_init_connect_env ()
1356{ 1375{
1357 vpn->script_init_env (); 1376 vpn->script_init_env ();
1358 1377
1359 char *env; 1378 char *env;
1360 asprintf (&env, "DESTID=%d", conf->id); putenv (env); 1379 asprintf (&env, "DESTID=%d", conf->id); putenv (env);
1380 asprintf (&env, "DESTSI=%s", (const char *)si); putenv (env);
1361 asprintf (&env, "DESTNODE=%s", conf->nodename); putenv (env); 1381 asprintf (&env, "DESTNODE=%s", conf->nodename); putenv (env);
1362 asprintf (&env, "DESTIP=%s", si.ntoa ()); putenv (env); 1382 asprintf (&env, "DESTIP=%s", si.ntoa ()); putenv (env);
1363 asprintf (&env, "DESTPORT=%d", ntohs (si.port)); putenv (env); 1383 asprintf (&env, "DESTPORT=%d", ntohs (si.port)); putenv (env);
1364} 1384}
1365 1385
1366inline const char * 1386inline const char *
1367connection::script_node_up () 1387connection::script_node_up ()
1368{ 1388{
… …
1373 char *filename; 1393 char *filename;
1374 asprintf (&filename, 1394 asprintf (&filename,
1375 "%s/%s", 1395 "%s/%s",
1376 confbase, 1396 confbase,
1377 ::conf.script_node_up ? ::conf.script_node_up : "node-up"); 1397 ::conf.script_node_up ? ::conf.script_node_up : "node-up");
1398
1399 return filename;
1400}
1401
1402inline const char *
1403connection::script_node_change ()
1404{
1405 script_init_connect_env ();
1406
1407 putenv ((char *)"STATE=change");
1408
1409 char *filename;
1410 asprintf (&filename,
1411 "%s/%s",
1412 confbase,
1413 ::conf.script_node_change ? ::conf.script_node_change : "node-change");
1378 1414
1379 return filename; 1415 return filename;
1380} 1416}
1381 1417
1382inline const char * 1418inline const char *
… …
1408 establish_connection.set<connection, &connection::establish_connection_cb> (this); 1444 establish_connection.set<connection, &connection::establish_connection_cb> (this);
1409 1445
1410 last_establish_attempt = 0.; 1446 last_establish_attempt = 0.;
1411 octx = ictx = 0; 1447 octx = ictx = 0;
1412 1448
1413 if (!conf->protocols) // make sure some protocol is enabled
1414 conf->protocols = PROT_UDPv4;
1415
1416 connectmode = conf->connectmode; 1449 connectmode = conf->connectmode;
1417 1450
1418 // queue a dummy packet to force an initial connection attempt 1451 // queue a dummy packet to force an initial connection attempt
1419 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED) 1452 if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED)
1420 vpn_queue.put (new net_packet); 1453 vpn_queue.put (new net_packet);
1421 1454
1422 reset_connection (); 1455 reset_connection ("startup");
1423} 1456}
1424 1457
1425connection::~connection () 1458connection::~connection ()
1426{ 1459{
1427 shutdown (); 1460 shutdown ();
1428} 1461}
1429 1462
1463void
1430void connection_init () 1464connection_init ()
1431{ 1465{
1432 auth_rate_limiter.clear (); 1466 auth_rate_limiter.clear ();
1433 reset_rate_limiter.clear (); 1467 reset_rate_limiter.clear ();
1434} 1468}
1435 1469

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