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/*
* anytun
*
* The secure anycast tunneling protocol (satp) defines a protocol used
* for communication between any combination of unicast and anycast
* tunnel endpoints. It has less protocol overhead than IPSec in Tunnel
* mode and allows tunneling of every ETHER TYPE protocol (e.g.
* ethernet, ip, arp ...). satp directly includes cryptography and
* message authentication based on the methodes used by SRTP. It is
* intended to deliver a generic, scaleable and secure solution for
* tunneling and relaying of packets of any protocol.
*
*
* Copyright (C) 2007 anytun.org <satp@wirdorange.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (see the file COPYING included with this
* distribution); if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <iostream>
#include <poll.h>
#include <gcrypt.h> // for thread safe libgcrypt initialisation
#include <cerrno> // for ENOMEM
#include "datatypes.h"
#include "log.h"
#include "buffer.h"
#include "plainPacket.h"
#include "encryptedPacket.h"
#include "cypher.h"
#include "keyDerivation.h"
#include "authAlgo.h"
#include "authTag.h"
#include "signalController.h"
#include "packetSource.h"
#include "tunDevice.h"
#include "options.h"
#include "seqWindow.h"
#include "connectionList.h"
#include "syncQueue.h"
#include "syncSocketHandler.h"
#include "syncListenSocket.h"
#include "syncSocket.h"
#include "syncClientSocket.h"
#include "syncCommand.h"
#include "threadParam.h"
#define PAYLOAD_TYPE_TAP 0x6558
#define PAYLOAD_TYPE_TUN 0x0800
#define SESSION_KEYLEN_AUTH 20
#define SESSION_KEYLEN_ENCR 16
#define SESSION_KEYLEN_SALT 14
uint8_t key[] = {
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p',
'q', 'r', 's', 't'
};
uint8_t salt[] = {
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
'i', 'j', 'k', 'l', 'm', 'n'
};
void createConnection(const std::string & remote_host , u_int16_t remote_port, ConnectionList & cl, u_int16_t seqSize, SyncQueue & queue)
{
SeqWindow * seq= new SeqWindow(seqSize);
seq_nr_t seq_nr_=0;
KeyDerivation * kd = new KeyDerivation;
kd->init(Buffer(key, sizeof(key)), Buffer(salt, sizeof(salt)));
cLog.msg(Log::PRIO_NOTICE) << "added connection remote host " << remote_host << ":" << remote_port;
ConnectionParam connparam ( (*kd), (*seq), seq_nr_, remote_host, remote_port);
cl.addConnection(connparam,0);
queue.push(SyncCommand(cl,0));
}
void addPacketAuthTag(EncryptedPacket& pack, AuthAlgo& a, ConnectionParam& conn)
{
AuthTag at = a.calc(pack);
pack.setAuthTag( at );
}
bool checkPacketAuthTag(EncryptedPacket& pack, AuthAlgo& a, ConnectionParam & conn)
{
// check auth_tag and remove it
AuthTag at = pack.getAuthTag();
return (at == a.calc(pack));
}
bool checkPacketSeqNr(EncryptedPacket& pack,ConnectionParam& conn)
{
// compare sender_id and seq with window
if(conn.seq_window_.hasSeqNr(pack.getSenderId(), pack.getSeqNr()))
{
cLog.msg(Log::PRIO_NOTICE) << "Replay attack from " << conn.remote_host_<<":"<< conn.remote_port_<< " seq:"<<pack.getSeqNr() << " sid: "<<pack.getSenderId();
return false;
}
conn.seq_window_.addSeqNr(pack.getSenderId(), pack.getSeqNr());
return true;
}
void* sender(void* p)
{
ThreadParam* param = reinterpret_cast<ThreadParam*>(p);
//TODO make Cypher selectable with command line option
AesIcmCypher c;
Sha1AuthAlgo a;
//TODO make pack global, reduce dynamic memory!
PlainPacket plain_packet(1600); // TODO: fix me... mtu size
EncryptedPacket packet(1600);
Buffer session_key(SESSION_KEYLEN_ENCR), session_salt(SESSION_KEYLEN_SALT), session_auth_key(SESSION_KEYLEN_AUTH);
//TODO replace mux
u_int16_t mux = 0;
while(1)
{
packet.setLength( packet.getSize() );
plain_packet.setLength( plain_packet.getSize() );
// read packet from device
u_int32_t len = param->dev.read(plain_packet);
plain_packet.setLength(len);
if( param->cl.empty())
continue;
ConnectionMap::iterator cit = param->cl.getConnection(mux);
if(cit==param->cl.getEnd())
continue;
ConnectionParam & conn = cit->second;
// add payload type
if(param->dev.getType() == TunDevice::TYPE_TUN)
plain_packet.setPayloadType(PAYLOAD_TYPE_TUN);
else if(param->dev.getType() == TunDevice::TYPE_TAP)
plain_packet.setPayloadType(PAYLOAD_TYPE_TAP);
else
plain_packet.setPayloadType(0);
// encrypt packet
conn.kd_.generate(LABEL_SATP_ENCRYPTION, conn.seq_nr_, session_key, session_key.getLength());
conn.kd_.generate(LABEL_SATP_SALT, conn.seq_nr_, session_salt, session_salt.getLength());
conn.kd_.generate(LABEL_SATP_MSG_AUTH, packet.getSeqNr(), session_auth_key, session_auth_key.getLength());
c.setKey(session_key);
c.setSalt(session_salt);
c.cypher(packet, plain_packet, plain_packet.getLength(), conn.seq_nr_, param->opt.getSenderId());
packet.setHeader(conn.seq_nr_, param->opt.getSenderId(), mux);
conn.seq_nr_++;
a.setKey(session_auth_key);
addPacketAuthTag(packet, a, conn);
param->src.send(packet, conn.remote_host_, conn.remote_port_);
}
pthread_exit(NULL);
}
void* syncConnector(void* p )
{
ThreadParam* param = reinterpret_cast<ThreadParam*>(p);
SocketHandler h;
SyncClientSocket sock(h,param->cl);
// sock.EnableSSL();
sock.Open( param->connto.host, param->connto.port);
h.Add(&sock);
while (h.GetCount())
{
h.Select();
}
pthread_exit(NULL);
}
void* syncListener(void* p )
{
ThreadParam* param = reinterpret_cast<ThreadParam*>(p);
SyncSocketHandler h(param->queue);
SyncListenSocket<SyncSocket,ConnectionList> l(h,param->cl);
if (l.Bind(param->opt.getLocalSyncPort()))
pthread_exit(NULL);
Utility::ResolveLocal(); // resolve local hostname
h.Add(&l);
h.Select(1,0);
while (1)
{
h.Select(1,0);
}
}
void* receiver(void* p)
{
ThreadParam* param = reinterpret_cast<ThreadParam*>(p);
AesIcmCypher c;
Sha1AuthAlgo a;
EncryptedPacket packet(1600); // TODO: dynamic mtu size
PlainPacket plain_packet(1600);
Buffer session_key(SESSION_KEYLEN_SALT), session_salt(SESSION_KEYLEN_SALT), session_auth_key(SESSION_KEYLEN_AUTH);
while(1)
{
string remote_host;
u_int16_t remote_port;
packet.setLength( packet.getSize() );
plain_packet.setLength( plain_packet.getSize() );
// u_int16_t sid = 0, seq = 0;
// read packet from socket
u_int32_t len = param->src.recv(packet, remote_host, remote_port);
packet.setLength(len);
// autodetect peer
// TODO check auth tag first
// this should be done by keymanagement anyway
if(param->opt.getRemoteAddr() == "" && param->cl.empty())
{
cLog.msg(Log::PRIO_NOTICE) << "autodetected remote host " << remote_host << ":" << remote_port;
createConnection(remote_host, remote_port, param->cl,param->opt.getSeqWindowSize(),param->queue);
}
//TODO Add multi connection support here
ConnectionParam & conn = param->cl.getConnection(0)->second;
conn.kd_.generate(LABEL_SATP_MSG_AUTH, packet.getSeqNr(), session_auth_key, session_auth_key.getLength());
a.setKey( session_auth_key );
if(!checkPacketAuthTag(packet, a, conn))
continue;
//Allow dynamic IP changes
//TODO add command line option to turn this off
if (remote_host != conn.remote_host_ || remote_port != conn.remote_port_)
{
cLog.msg(Log::PRIO_NOTICE) << "autodetected remote host ip changed " << remote_host << ":" << remote_port;
conn.remote_host_=remote_host;
conn.remote_port_=remote_port;
param->queue.push(SyncCommand(param->cl,0));
}
// Replay Protection
if (!checkPacketSeqNr(packet, conn))
continue;
// decrypt packet
conn.kd_.generate(LABEL_SATP_ENCRYPTION, packet.getSeqNr(), session_key, session_key.getLength());
conn.kd_.generate(LABEL_SATP_SALT, packet.getSeqNr(), session_salt, session_salt.getLength());
c.setKey(session_key);
c.setSalt(session_salt);
c.cypher(plain_packet, packet, packet.getLength(), packet.getSeqNr(), packet.getSenderId());
// check payload_type and remove it
if((param->dev.getType() == TunDevice::TYPE_TUN && plain_packet.getPayloadType() != PAYLOAD_TYPE_TUN) ||
(param->dev.getType() == TunDevice::TYPE_TAP && plain_packet.getPayloadType() != PAYLOAD_TYPE_TAP))
continue;
// write it on the device
param->dev.write(plain_packet);
}
pthread_exit(NULL);
}
extern "C" {
GCRY_THREAD_OPTION_PTHREAD_IMPL;
}
int main(int argc, char* argv[])
{
std::cout << "anytun - secure anycast tunneling protocol" << std::endl;
Options opt;
if(!opt.parse(argc, argv))
{
opt.printUsage();
exit(-1);
}
cLog.msg(Log::PRIO_NOTICE) << "anytun started...";
SignalController sig;
sig.init();
std::string dev_type(opt.getDevType());
TunDevice dev(opt.getDevName().c_str(), dev_type=="" ? NULL : dev_type.c_str(), opt.getIfconfigParamLocal().c_str(), opt.getIfconfigParamRemoteNetmask().c_str());
PacketSource* src;
if(opt.getLocalAddr() == "")
src = new UDPPacketSource(opt.getLocalPort());
else
src = new UDPPacketSource(opt.getLocalAddr(), opt.getLocalPort());
ConnectionList cl;
ConnectToList connect_to = opt.getConnectTo();
SyncQueue queue;
if(opt.getRemoteAddr() != "")
createConnection(opt.getRemoteAddr(),opt.getRemotePort(),cl,opt.getSeqWindowSize(), queue);
ThreadParam p(opt, dev, *src, cl, queue,*(new OptionConnectTo()));
cLog.msg(Log::PRIO_NOTICE) << "dev created (opened)";
cLog.msg(Log::PRIO_NOTICE) << "dev opened - actual name is '" << p.dev.getActualName() << "'";
cLog.msg(Log::PRIO_NOTICE) << "dev type is '" << p.dev.getTypeString() << "'";
gcry_control( GCRYCTL_SET_THREAD_CBS, &gcry_threads_pthread );
pthread_t senderThread;
pthread_create(&senderThread, NULL, sender, &p);
pthread_t receiverThread;
pthread_create(&receiverThread, NULL, receiver, &p);
pthread_t syncListenerThread;
if ( opt.getLocalSyncPort())
pthread_create(&syncListenerThread, NULL, syncListener, &p);
std::list<pthread_t> connectThreads;
for(ConnectToList::iterator it = connect_to.begin() ;it != connect_to.end(); ++it)
{
connectThreads.push_back(pthread_t());
ThreadParam * point = new ThreadParam(opt, dev, *src, cl, queue,*it);
pthread_create(& connectThreads.back(), NULL, syncConnector, point);
}
int ret = sig.run();
pthread_cancel(senderThread);
pthread_cancel(receiverThread);
if ( opt.getLocalSyncPort())
pthread_cancel(syncListenerThread);
for( std::list<pthread_t>::iterator it = connectThreads.begin() ;it != connectThreads.end(); ++it)
pthread_cancel(*it);
pthread_join(senderThread, NULL);
pthread_join(receiverThread, NULL);
if ( opt.getLocalSyncPort())
pthread_join(syncListenerThread, NULL);
for( std::list<pthread_t>::iterator it = connectThreads.begin() ;it != connectThreads.end(); ++it)
pthread_join(*it, NULL);
delete src;
return ret;
}
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