anytun.cpp

   1 /*
   2  *  anytun
   3  *
   4  *  The secure anycast tunneling protocol (satp) defines a protocol used
   5  *  for communication between any combination of unicast and anycast
   6  *  tunnel endpoints.  It has less protocol overhead than IPSec in Tunnel
   7  *  mode and allows tunneling of every ETHER TYPE protocol (e.g.
   8  *  ethernet, ip, arp ...). satp directly includes cryptography and
   9  *  message authentication based on the methodes used by SRTP.  It is
  10  *  intended to deliver a generic, scaleable and secure solution for
  11  *  tunneling and relaying of packets of any protocol.
  12  *
  13  *
  14  *  Copyright (C) 2007 anytun.org <satp@wirdorange.org>
  15  *
  16  *  This program is free software; you can redistribute it and/or modify
  17  *  it under the terms of the GNU General Public License version 2
  18  *  as published by the Free Software Foundation.
  19  *
  20  *  This program is distributed in the hope that it will be useful,
  21  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  *  GNU General Public License for more details.
  24  *
  25  *  You should have received a copy of the GNU General Public License
  26  *  along with this program (see the file COPYING included with this
  27  *  distribution); if not, write to the Free Software Foundation, Inc.,
  28  *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  29  */
  30
  31 #include <iostream>
  32 #include <poll.h>
  33
  34 #include <gcrypt.h>
  35 #include <cerrno>     // for ENOMEM
  36
  37 #include "datatypes.h"
  38
  39 #include "log.h"
  40 #include "buffer.h"
  41 #include "plainPacket.h"
  42 #include "encryptedPacket.h"
  43 #include "cipher.h"
  44 #include "keyDerivation.h"
  45 #include "authAlgo.h"
  46 #include "authTag.h"
  47 #include "cipherFactory.h"
  48 #include "authAlgoFactory.h"
  49 #include "keyDerivationFactory.h"
  50 #include "signalController.h"
  51 #include "packetSource.h"
  52 #include "tunDevice.h"
  53 #include "options.h"
  54 #include "seqWindow.h"
  55 #include "connectionList.h"
  56 #include "routingTable.h"
  57 #include "networkAddress.h"
  58
  59 #include "syncQueue.h"
  60 #include "syncSocketHandler.h"
  61 #include "syncListenSocket.h"
  62
  63 #include "syncSocket.h"
  64 #include "syncClientSocket.h"
  65 #include "syncCommand.h"
  66
  67 #include "threadParam.h"
  68
  69 #define MAX_PACKET_LENGTH 1600
  70
  71 #define SESSION_KEYLEN_AUTH 20   // TODO: hardcoded size
  72 #define SESSION_KEYLEN_ENCR 16   // TODO: hardcoded size
  73 #define SESSION_KEYLEN_SALT 14   // TODO: hardcoded size
  74
  75 void createConnection(const std::string & remote_host, u_int16_t remote_port, ConnectionList & cl, u_int16_t seqSize, SyncQueue & queue, mux_t mux)
  76 {
  77         SeqWindow * seq= new SeqWindow(seqSize);
  78         seq_nr_t seq_nr_=0;
  79   KeyDerivation * kd = KeyDerivationFactory::create(gOpt.getKdPrf());
  80   kd->init(gOpt.getKey(), gOpt.getSalt());
  81   cLog.msg(Log::PRIO_NOTICE) << "added connection remote host " << remote_host << ":" << remote_port;
  82         ConnectionParam connparam ( (*kd),  (*seq), seq_nr_, remote_host,  remote_port);
  83         cl.addConnection(connparam,mux);
  84         NetworkAddress addr(ipv4,gOpt.getIfconfigParamRemoteNetmask().c_str());
  85         NetworkPrefix prefix(addr);
  86         gRoutingTable.addRoute(prefix,mux);
  87   SyncCommand sc (cl,mux);
  88         queue.push(sc);
  89   SyncCommand sc2 (prefix);
  90         queue.push(sc2);
  91 }
  92
  93
  94 void addPacketAuthTag(EncryptedPacket& pack, AuthAlgo* a, ConnectionParam& conn)
  95 {
  96   AuthTag at = a->calc(pack);
  97   pack.setAuthTag( at );
  98 }
  99
 100 bool checkPacketAuthTag(EncryptedPacket& pack, AuthAlgo* a, ConnectionParam & conn)
 101 {
 102   // check auth_tag and remove it
 103   AuthTag at = pack.getAuthTag();
 104   return (at == a->calc(pack));
 105 }
 106
 107 bool checkPacketSeqNr(EncryptedPacket& pack,ConnectionParam& conn)
 108 {
 109         // compare sender_id and seq with window
 110         if(conn.seq_window_.hasSeqNr(pack.getSenderId(), pack.getSeqNr()))
 111         {
 112                 cLog.msg(Log::PRIO_NOTICE) << "Replay attack from " << conn.remote_host_<<":"<< conn.remote_port_
 113                                << " seq:"<<pack.getSeqNr() << " sid: "<<pack.getSenderId();
 114                 return false;
 115         }
 116
 117         conn.seq_window_.addSeqNr(pack.getSenderId(), pack.getSeqNr());
 118         return true;
 119 }
 120
 121 void* sender(void* p)
 122 {
 123   ThreadParam* param = reinterpret_cast<ThreadParam*>(p);
 124
 125   std::auto_ptr<Cipher> c(CipherFactory::create(gOpt.getCipher()));
 126 //  std::auto_ptr<AuthAlgo> a(AuthAlgoFactory::create(gOpt.getAuthAlgo()) );
 127
 128   PlainPacket plain_packet(MAX_PACKET_LENGTH);
 129   EncryptedPacket encrypted_packet(MAX_PACKET_LENGTH);
 130
 131   Buffer session_key(u_int32_t(SESSION_KEYLEN_ENCR));             // TODO: hardcoded size
 132   Buffer session_salt(u_int32_t(SESSION_KEYLEN_SALT));            // TODO: hardcoded size
 133   Buffer session_auth_key(u_int32_t(SESSION_KEYLEN_AUTH));        // TODO: hardcoded size
 134
 135   //TODO replace mux
 136   u_int16_t mux = gOpt.getMux();
 137   while(1)
 138   {
 139     plain_packet.setLength(MAX_PACKET_LENGTH);
 140     encrypted_packet.setLength(MAX_PACKET_LENGTH);
 141     // read packet from device
 142     u_int32_t len = param->dev.read(plain_packet.getPayload(), plain_packet.getPayloadLength());
 143     plain_packet.setPayloadLength(len);
 144
 145     if(param->cl.empty())
 146       continue;
 147
 148                 mux = gRoutingTable.getRoute(NetworkAddress());
 149     ConnectionMap::iterator cit = param->cl.getConnection(mux);
 150                 if(cit==param->cl.getEnd())
 151                         continue;
 152                 ConnectionParam & conn = cit->second;
 153
 154     // set payload type
 155     if(param->dev.getType() == TunDevice::TYPE_TUN)
 156       plain_packet.setPayloadType(PAYLOAD_TYPE_TUN);
 157     else if(param->dev.getType() == TunDevice::TYPE_TAP)
 158       plain_packet.setPayloadType(PAYLOAD_TYPE_TAP);
 159     else
 160       plain_packet.setPayloadType(0);
 161
 162     // generate packet-key
 163     conn.kd_.generate(LABEL_SATP_ENCRYPTION, conn.seq_nr_, session_key);
 164     conn.kd_.generate(LABEL_SATP_SALT, conn.seq_nr_, session_salt);
 165
 166     c->setKey(session_key);
 167     c->setSalt(session_salt);
 168
 169     // encrypt packet
 170     c->encrypt(plain_packet, encrypted_packet, conn.seq_nr_, gOpt.getSenderId());
 171
 172     encrypted_packet.setHeader(conn.seq_nr_, gOpt.getSenderId(), mux);
 173     conn.seq_nr_++;
 174
 175         // TODO: activate authentication
 176 //    conn.kd_.generate(LABEL_SATP_MSG_AUTH, encrypted_packet.getSeqNr(), session_auth_key);
 177 //    a->setKey(session_auth_key);
 178 //              addPacketAuthTag(encrypted_packet, a.get(), conn);
 179
 180     param->src.send(encrypted_packet.getBuf(), encrypted_packet.getLength(), conn.remote_host_, conn.remote_port_);
 181   }
 182   pthread_exit(NULL);
 183 }
 184
 185 void* syncConnector(void* p )
 186 {
 187         ThreadParam* param = reinterpret_cast<ThreadParam*>(p);
 188
 189         SocketHandler h;
 190         SyncClientSocket sock(h,param->cl);
 191         //      sock.EnableSSL();
 192         sock.Open( param->connto.host, param->connto.port);
 193         h.Add(&sock);
 194         while (h.GetCount())
 195         {
 196                 h.Select();
 197         }
 198   pthread_exit(NULL);
 199 }
 200
 201 void* syncListener(void* p )
 202 {
 203         ThreadParam* param = reinterpret_cast<ThreadParam*>(p);
 204
 205         SyncSocketHandler h(param->queue);
 206         SyncListenSocket<SyncSocket,ConnectionList> l(h,param->cl);
 207
 208         if (l.Bind(gOpt.getLocalSyncPort()))
 209                 pthread_exit(NULL);
 210
 211         Utility::ResolveLocal(); // resolve local hostname
 212         h.Add(&l);
 213         h.Select(1,0);
 214         while (1) {
 215                 h.Select(1,0);
 216         }
 217 }
 218
 219 void* receiver(void* p)
 220 {
 221   ThreadParam* param = reinterpret_cast<ThreadParam*>(p);
 222
 223   std::auto_ptr<Cipher> c( CipherFactory::create(gOpt.getCipher()) );
 224 //  std::auto_ptr<AuthAlgo> a( AuthAlgoFactory::create(gOpt.getAuthAlgo()) );
 225
 226   EncryptedPacket encrypted_packet(MAX_PACKET_LENGTH);
 227   PlainPacket plain_packet(MAX_PACKET_LENGTH);
 228
 229   Buffer session_key(u_int32_t(SESSION_KEYLEN_ENCR));             // TODO: hardcoded size
 230   Buffer session_salt(u_int32_t(SESSION_KEYLEN_SALT));            // TODO: hardcoded size
 231   Buffer session_auth_key(u_int32_t(SESSION_KEYLEN_AUTH));        // TODO: hardcoded size
 232
 233   while(1)
 234   {
 235     string remote_host;
 236     u_int16_t remote_port;
 237
 238     plain_packet.setLength(MAX_PACKET_LENGTH);
 239     encrypted_packet.setLength(MAX_PACKET_LENGTH);
 240
 241     // read packet from socket
 242     u_int32_t len = param->src.recv(encrypted_packet.getBuf(), encrypted_packet.getLength(), remote_host, remote_port);
 243     encrypted_packet.setLength(len);
 244
 245                 // TODO: check auth tag first
 246 //    conn.kd_.generate(LABEL_SATP_MSG_AUTH, encrypted_packet.getSeqNr(), session_auth_key);
 247 //    a->setKey( session_auth_key );
 248 //              if(!checkPacketAuthTag(encrypted_packet, a.get(), conn))
 249 //                      continue;
 250
 251
 252     // autodetect peer
 253     if(gOpt.getRemoteAddr() == "" && param->cl.empty())
 254                 {
 255       cLog.msg(Log::PRIO_NOTICE) << "autodetected remote host " << remote_host << ":" << remote_port;
 256                         createConnection(remote_host, remote_port, param->cl, gOpt.getSeqWindowSize(),param->queue,encrypted_packet.getMux());
 257                 }
 258
 259                 // TODO: Add multi connection support here
 260                 ConnectionMap::iterator cit = param->cl.getConnection(encrypted_packet.getMux());
 261                 if (cit == param->cl.getEnd())
 262                         continue;
 263                 ConnectionParam & conn = cit->second;
 264
 265                 //Allow dynamic IP changes
 266                 //TODO: add command line option to turn this off
 267                 if (remote_host != conn.remote_host_ || remote_port != conn.remote_port_)
 268                 {
 269       cLog.msg(Log::PRIO_NOTICE) << "autodetected remote host ip changed " << remote_host << ":" << remote_port;
 270                         conn.remote_host_=remote_host;
 271                         conn.remote_port_=remote_port;
 272                         SyncCommand sc (param->cl,0);
 273                         param->queue.push(sc);
 274                 }
 275
 276                 // Replay Protection
 277                 if (!checkPacketSeqNr(encrypted_packet, conn))
 278                         continue;
 279
 280     // generate packet-key
 281     conn.kd_.generate(LABEL_SATP_ENCRYPTION, encrypted_packet.getSeqNr(), session_key);
 282     conn.kd_.generate(LABEL_SATP_SALT, encrypted_packet.getSeqNr(), session_salt);
 283     c->setKey(session_key);
 284     c->setSalt(session_salt);
 285
 286     // decrypt packet
 287     c->decrypt(encrypted_packet, plain_packet);
 288
 289     // check payload_type
 290     if((param->dev.getType() == TunDevice::TYPE_TUN && plain_packet.getPayloadType() != PAYLOAD_TYPE_TUN) ||
 291        (param->dev.getType() == TunDevice::TYPE_TAP && plain_packet.getPayloadType() != PAYLOAD_TYPE_TAP))
 292       continue;
 293
 294     // write it on the device
 295     param->dev.write(plain_packet.getPayload(), plain_packet.getLength());
 296   }
 297   pthread_exit(NULL);
 298 }
 299
 300 #define MIN_GCRYPT_VERSION "1.2.3"
 301 // make libgcrypt thread safe
 302 extern "C" {
 303 GCRY_THREAD_OPTION_PTHREAD_IMPL;
 304 }
 305
 306 bool initLibGCrypt()
 307 {
 308   // make libgcrypt thread safe
 309   // this must be called before any other libgcrypt call
 310   gcry_control( GCRYCTL_SET_THREAD_CBS, &gcry_threads_pthread );
 311
 312   // this must be called right after the GCRYCTL_SET_THREAD_CBS command
 313   // no other function must be called till now
 314   if( !gcry_check_version( MIN_GCRYPT_VERSION ) ) {
 315     std::cout << "initLibGCrypt: Invalid Version of libgcrypt, should be >= " << MIN_GCRYPT_VERSION << std::endl;
 316     return false;
 317   }
 318
 319   // Tell Libgcrypt that initialization has completed.
 320   gcry_error_t err = gcry_control(GCRYCTL_INITIALIZATION_FINISHED);
 321   if( err ) {
 322     std::cout << "initLibGCrypt: Failed to finish the initialization of libgcrypt: " << gpg_strerror( err ) << std::endl;
 323     return false;
 324   }
 325
 326   cLog.msg(Log::PRIO_NOTICE) << "initLibGCrypt: libgcrypt init finished";
 327   return true;
 328 }
 329
 330 int main(int argc, char* argv[])
 331 {
 332   std::cout << "anytun - secure anycast tunneling protocol" << std::endl;
 333   if(!gOpt.parse(argc, argv))
 334   {
 335     gOpt.printUsage();
 336     exit(-1);
 337   }
 338   cLog.msg(Log::PRIO_NOTICE) << "anytun started...";
 339
 340   SignalController sig;
 341   sig.init();
 342   std::string dev_type(gOpt.getDevType());
 343   TunDevice dev(gOpt.getDevName().c_str(), dev_type=="" ? NULL : dev_type.c_str(), gOpt.getIfconfigParamLocal().c_str(), gOpt.getIfconfigParamRemoteNetmask().c_str());
 344
 345   PacketSource* src;
 346   if(gOpt.getLocalAddr() == "")
 347     src = new UDPPacketSource(gOpt.getLocalPort());
 348   else
 349     src = new UDPPacketSource(gOpt.getLocalAddr(), gOpt.getLocalPort());
 350
 351         ConnectionList cl;
 352         ConnectToList connect_to = gOpt.getConnectTo();
 353         SyncQueue queue;
 354
 355         if(gOpt.getRemoteAddr() != "")
 356                 createConnection(gOpt.getRemoteAddr(),gOpt.getRemotePort(),cl,gOpt.getSeqWindowSize(), queue, gOpt.getMux());
 357
 358   ThreadParam p(dev, *src, cl, queue,*(new OptionConnectTo()));
 359
 360   cLog.msg(Log::PRIO_NOTICE) << "dev created (opened)";
 361   cLog.msg(Log::PRIO_NOTICE) << "dev opened - actual name is '" << p.dev.getActualName() << "'";
 362   cLog.msg(Log::PRIO_NOTICE) << "dev type is '" << p.dev.getTypeString() << "'";
 363
 364   // this must be called before any other libgcrypt call
 365   if(!initLibGCrypt())
 366     return -1;
 367
 368   pthread_t senderThread;
 369   pthread_create(&senderThread, NULL, sender, &p);
 370   pthread_t receiverThread;
 371   pthread_create(&receiverThread, NULL, receiver, &p);
 372
 373         pthread_t syncListenerThread;
 374         if ( gOpt.getLocalSyncPort())
 375                 pthread_create(&syncListenerThread, NULL, syncListener, &p);
 376
 377         std::list<pthread_t> connectThreads;
 378         for(ConnectToList::iterator it = connect_to.begin() ;it != connect_to.end(); ++it)
 379         {
 380          connectThreads.push_back(pthread_t());
 381          ThreadParam * point = new ThreadParam(dev, *src, cl, queue,*it);
 382          pthread_create(& connectThreads.back(),  NULL, syncConnector, point);
 383         }
 384
 385         int ret = sig.run();
 386
 387   pthread_cancel(senderThread);
 388   pthread_cancel(receiverThread);
 389         if ( gOpt.getLocalSyncPort())
 390           pthread_cancel(syncListenerThread);
 391         for( std::list<pthread_t>::iterator it = connectThreads.begin() ;it != connectThreads.end(); ++it)
 392                 pthread_cancel(*it);
 393
 394   pthread_join(senderThread, NULL);
 395   pthread_join(receiverThread, NULL);
 396         if ( gOpt.getLocalSyncPort())
 397           pthread_join(syncListenerThread, NULL);
 398
 399         for( std::list<pthread_t>::iterator it = connectThreads.begin() ;it != connectThreads.end(); ++it)
 400           pthread_join(*it, NULL);
 401
 402   delete src;
 403         delete &p.connto;
 404
 405   return ret;
 406 }
 407