/* * libretroshare/src/chat: distantchat.cc * * Services for RetroShare. * * Copyright 2014 by Cyril Soler * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License Version 2 as published by the Free Software Foundation. * * This library 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 * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 * USA. * * Please report all bugs and problems to "csoler@users.sourceforge.net". * */ #include #include "openssl/rand.h" #include "openssl/dh.h" #include "openssl/err.h" #include "util/rsaes.h" #include "util/rsprint.h" #include #include #include #include #include #include #include #include "p3gxstunnel.h" #define DEBUG_GXS_TUNNEL static const uint32_t GXS_TUNNEL_KEEP_ALIVE_TIMEOUT = 6 ; // send keep alive packet so as to avoid tunnel breaks. static const uint32_t RS_GXS_TUNNEL_DH_STATUS_UNINITIALIZED = 0x0000 ; static const uint32_t RS_GXS_TUNNEL_DH_STATUS_HALF_KEY_DONE = 0x0001 ; static const uint32_t RS_GXS_TUNNEL_DH_STATUS_KEY_AVAILABLE = 0x0002 ; static const uint32_t RS_GXS_TUNNEL_STATUS_UNKNOWN = 0x00 ; static const uint32_t RS_GXS_TUNNEL_STATUS_CAN_TALK = 0x01 ; static const uint32_t RS_GXS_TUNNEL_STATUS_TUNNEL_DN = 0x02 ; static const uint32_t RS_GXS_TUNNEL_STATUS_REMOTELY_CLOSED = 0x03 ; static const uint32_t GXS_TUNNEL_ENCRYPTION_HMAC_SIZE = SHA_DIGEST_LENGTH ; static const uint32_t GXS_TUNNEL_ENCRYPTION_IV_SIZE = 8 ; void p3GxsTunnelService::connectToTurtleRouter(p3turtle *tr) { mTurtle = tr ; tr->registerTunnelService(this) ; } void p3GxsTunnelService::flush() { // Flush items that could not be sent, probably because of a Mutex protected zone. // while(!pendingGxsTunnelItems.empty()) { sendTurtleData(pendingGxsTunnelItems.front() ) ; pendingGxsTunnelItems.pop_front() ; } // TODO: also sweep GXS id map and disable any ID with no virtual peer id in the list. RS_STACK_MUTEX(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ time_t now = time(NULL) ; for(std::map::iterator it(_gxs_tunnel_contacts.begin());it!=_gxs_tunnel_contacts.end();++it) { if(it->second.last_contact+20+GXS_TUNNEL_KEEP_ALIVE_TIMEOUT < now && it->second.status == RS_GXS_TUNNEL_STATUS_CAN_TALK) { std::cerr << "(II) GxsTunnelService:: connexion interrupted with peer." << std::endl; it->second.status = RS_GXS_TUNNEL_STATUS_TUNNEL_DN ; it->second.virtual_peer_id.clear() ; // Also reset turtle router monitoring so as to make the tunnel handling more responsive. If we don't do that, // the TR will wait 60 secs for the tunnel to die, which causes a significant waiting time in the chat window. if(it->second.direction == RsTurtleGenericTunnelItem::DIRECTION_SERVER) { std::cerr << "(II) GxsTunnelService:: forcing new tunnel campain." << std::endl; #warning make sure we can use random here. mTurtle->forceReDiggTunnels( randomHashFromDestinationGxsId(it->second.to_gxs_id) ); } } if(it->second.last_keep_alive_sent + GXS_TUNNEL_KEEP_ALIVE_TIMEOUT < now && it->second.status == RS_GXS_TUNNEL_STATUS_CAN_TALK) { RsGxsTunnelStatusItem *cs = new RsGxsTunnelStatusItem ; cs->flags = RS_GXS_TUNNEL_FLAG_KEEP_ALIVE; cs->PeerId(it->second.virtual_peer_id) ; // we send off-mutex to avoid deadlock. pendingGxsTunnelItems.push_back(cs) ; it->second.last_keep_alive_sent = now ; #ifdef DEBUG_GXS_TUNNEL std::cerr << "(II) GxsTunnelService:: Sending keep alive packet to gxs id " << it->first << std::endl; #endif } } } bool p3GxsTunnelService::handleIncomingItem(RsGxsTunnelItem *item) { if(item == NULL) return false ; switch(item->PacketSubType()) { case RS_PKT_SUBTYPE_GXS_TUNNEL_DH_PUBLIC_KEY: handleRecvDHPublicKey(dynamic_cast(item)) ; break ; return true ; #warning need to implement tunnel data handling here case RS_PKT_SUBTYPE_GXS_TUNNEL_DATA: return true ; #warning need to implement tunnel data ACK handling here case RS_PKT_SUBTYPE_GXS_TUNNEL_DATA_ACK: return true ; case RS_PKT_SUBTYPE_GXS_TUNNEL_STATUS: handleRecvStatusItem(dynamic_cast(item)) ; return true ; default: return false ; } return false ; } //#warning is this function still used?? //bool p3GxsTunnelService::handleOutgoingItem(RsGxsTunnelItem *item) //{ // { // RS_STACK_MUTEX(mGxsTunnelMtx) ; // // std::map::const_iterator it=_gxs_tunnel_contacts.find(RsGxsId(item->PeerId())); // // if(it == _gxs_tunnel_contacts.end()) // return false ; // } // //#ifdef CHAT_DEBUG // std::cerr << "p3GxsTunnelService::handleOutgoingItem(): sending to " << item->PeerId() << ": interpreted as a distant chat virtual peer id." << std::endl; //#endif // sendTurtleData(item) ; // return true; //} void p3GxsTunnelService::handleRecvStatusItem(RsGxsTunnelStatusItem *cs) { if(cs->flags & RS_GXS_TUNNEL_FLAG_CLOSING_DISTANT_CONNECTION) { RsGxsTunnelId tunnel_id ; TurtleVirtualPeerId vpid = cs->PeerId() ; { RS_STACK_MUTEX(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ std::map::iterator it = _gxs_tunnel_virtual_peer_ids.find(vpid) ; if(it == _gxs_tunnel_virtual_peer_ids.end()) { std::cerr << " (EE) Cannot find hash in gxs_tunnel peer list!!" << std::endl; return ; } tunnel_id = it->second.tunnel_id ; } markGxsTunnelAsClosed(tunnel_id); } // nothing more to do, because the decryption routing will update the last_contact time when decrypting. if(cs->flags & RS_GXS_TUNNEL_FLAG_KEEP_ALIVE) std::cerr << "GxsTunnelService::handleRecvGxsTunnelStatusItem(): received keep alive packet for inactive tunnel! peerId=" << cs->PeerId() << std::endl; } bool p3GxsTunnelService::handleTunnelRequest(const RsFileHash& hash,const RsPeerId& /*peer_id*/) { RsStackMutex stack(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ // look into owned GXS ids, and see if the hash corresponds to the expected hash // std::list own_id_list ; rsIdentity->getOwnIds(own_id_list) ; // extract the GXS id from the hash RsGxsId destination_id = destinationGxsIdFromHash(hash) ; // linear search. Not costly because we have typically a low number of IDs. Otherwise, this really should be avoided! for(std::list::const_iterator it(own_id_list.begin());it!=own_id_list.end();++it) if(*it == destination_id) { #ifdef DEBUG_GXS_TUNNEL std::cerr << "GxsTunnelService::handleTunnelRequest: received tunnel request for hash " << hash << std::endl; std::cerr << " answering true!" << std::endl; #endif return true ; } return false ; } void p3GxsTunnelService::addVirtualPeer(const TurtleFileHash& hash,const TurtleVirtualPeerId& virtual_peer_id,RsTurtleGenericTunnelItem::Direction dir) { #ifdef DEBUG_GXS_TUNNEL std::cerr << "GxsTunnelService:: received new virtual peer " << virtual_peer_id << " for hash " << hash << ", dir=" << dir << std::endl; #endif RsGxsId own_gxs_id ; { RS_STACK_MUTEX(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ GxsTunnelDHInfo& dhinfo( _gxs_tunnel_virtual_peer_ids[virtual_peer_id] ) ; dhinfo.gxs_id.clear() ; if(dhinfo.dh != NULL) DH_free(dhinfo.dh) ; dhinfo.dh = NULL ; dhinfo.direction = dir ; dhinfo.hash = hash ; dhinfo.status = RS_GXS_TUNNEL_DH_STATUS_UNINITIALIZED ; dhinfo.tunnel_id.clear(); if(dir == RsTurtleGenericTunnelItem::DIRECTION_CLIENT) // server side { // check that a tunnel is not already working for this hash. If so, give up. own_gxs_id = destinationGxsIdFromHash(hash) ; } else // client side { std::map::const_iterator it ; while(it != _gxs_tunnel_contacts.end() && it->second.hash != hash) ++it ; if(it == _gxs_tunnel_contacts.end()) { std::cerr << "(EE) no pre-registered peer for hash " << hash << " on client side. This is a bug." << std::endl; return ; } if(it->second.status == RS_GXS_TUNNEL_STATUS_CAN_TALK) { std::cerr << " virtual peer is for a distant chat session that is already openned and alive. Giving it up." << std::endl; return ; } own_gxs_id = it->second.own_gxs_id ; } #ifdef DEBUG_GXS_TUNNEL std::cerr << " Creating new virtual peer ID entry and empty DH session key." << std::endl; #endif } #ifdef DEBUG_GXS_TUNNEL std::cerr << " Adding virtual peer " << virtual_peer_id << " for chat hash " << hash << std::endl; #endif // Start a new DH session for this tunnel RS_STACK_MUTEX(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ locked_restartDHSession(virtual_peer_id,own_gxs_id) ; } void p3GxsTunnelService::locked_restartDHSession(const RsPeerId& virtual_peer_id,const RsGxsId& own_gxs_id) { #ifdef DEBUG_GXS_TUNNEL std::cerr << "Starting new DH session." << std::endl; #endif GxsTunnelDHInfo& dhinfo = _gxs_tunnel_virtual_peer_ids[virtual_peer_id] ; // creates it, if necessary dhinfo.status = RS_GXS_TUNNEL_DH_STATUS_UNINITIALIZED ; dhinfo.own_gxs_id = own_gxs_id ; if(!locked_initDHSessionKey(dhinfo.dh)) { std::cerr << " (EE) Cannot start DH session. Something went wrong." << std::endl; return ; } dhinfo.status = RS_GXS_TUNNEL_DH_STATUS_HALF_KEY_DONE ; if(!locked_sendDHPublicKey(dhinfo.dh,own_gxs_id,virtual_peer_id)) std::cerr << " (EE) Cannot send DH public key. Something went wrong." << std::endl; } void p3GxsTunnelService::removeVirtualPeer(const TurtleFileHash& hash,const TurtleVirtualPeerId& virtual_peer_id) { bool tunnel_dn = false ; #ifdef DEBUG_GXS_TUNNEL std::cerr << "GxsTunnelService: Removing virtual peer " << virtual_peer_id << " for hash " << hash << std::endl; #else /* remove unused parameter warnings */ (void) hash; #endif { RsStackMutex stack(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ RsGxsId gxs_id ; std::map::iterator it = _gxs_tunnel_virtual_peer_ids.find(virtual_peer_id) ; if(it == _gxs_tunnel_virtual_peer_ids.end()) { std::cerr << "(EE) Cannot remove virtual peer " << virtual_peer_id << ": not found in tunnel list!!" << std::endl; return ; } RsGxsTunnelId tunnel_id = it->second.tunnel_id ; if(it->second.dh != NULL) DH_free(it->second.dh) ; _gxs_tunnel_virtual_peer_ids.erase(it) ; std::map::iterator it2 = _gxs_tunnel_contacts.find(tunnel_id) ; if(it2 == _gxs_tunnel_contacts.end()) { std::cerr << "(EE) Cannot find tunnel id " << tunnel_id << " in contact list. Weird." << std::endl; return ; } if(it2->second.virtual_peer_id == virtual_peer_id) { it2->second.status = RS_GXS_TUNNEL_STATUS_TUNNEL_DN ; it2->second.virtual_peer_id.clear() ; tunnel_dn = true ; } } if(tunnel_dn) { #warning we should notify the client here //RsServer::notify()->notifyChatStatus(ChatId(RsGxsId(virtual_peer_id)),"tunnel is down...") ; //RsServer::notify()->notifyPeerStatusChanged(virtual_peer_id.toStdString(),RS_STATUS_OFFLINE) ; } } void p3GxsTunnelService::receiveTurtleData(RsTurtleGenericTunnelItem *gitem,const RsFileHash& hash, const RsPeerId& virtual_peer_id,RsTurtleGenericTunnelItem::Direction direction) { #ifdef DEBUG_GXS_TUNNEL std::cerr << "GxsTunnelService::receiveTurtleData(): Received turtle data. " << std::endl; std::cerr << " hash = " << hash << std::endl; std::cerr << " vpid = " << virtual_peer_id << std::endl; std::cerr << " acting as = " << direction << std::endl; #else /* remove unused parameter warnings */ (void) direction; #endif RsTurtleGenericDataItem *item = dynamic_cast(gitem) ; if(item == NULL) { std::cerr << "(EE) item is not a data item. That is an error." << std::endl; return ; } // Call the AES crypto module // - the IV is the first 8 bytes of item->data_bytes if(item->data_size < 8) { std::cerr << "(EE) item encrypted data stream is too small: size = " << item->data_size << std::endl; return ; } if(*((uint64_t*)item->data_bytes) != 0) // WTF?? we should use flags { #ifdef DEBUG_GXS_TUNNEL std::cerr << " Item is encrypted." << std::endl; #endif // if cannot decrypt, it means the key is wrong. We need to re-negociate a new key. handleEncryptedData((uint8_t*)item->data_bytes,item->data_size,hash,virtual_peer_id) ; } else { #ifdef DEBUG_GXS_TUNNEL std::cerr << " Item is not encrypted." << std::endl; #endif // Now try deserialise the decrypted data to make an RsItem out of it. // #warning needs proper passing of item to client RsItem *citem = RsGxsTunnelSerialiser().deserialise(&((uint8_t*)item->data_bytes)[8],&item->data_size-8) ; if(citem == NULL) { std::cerr << "(EE) item could not be de-serialized. That is an error." << std::endl; return ; } // DH key items are sent even before we know who we speak to, so the virtual peer id is used in this // case only. if(dynamic_cast(citem) != NULL) { citem->PeerId(virtual_peer_id) ; handleIncomingItem(dynamic_cast(citem)) ; } else std::cerr << "(EE) Deserialiased item has unexpected type." << std::endl; } } // This function encrypts the given data and adds a MAC and an IV into a serialised memory chunk that is then sent through the tunnel. bool p3GxsTunnelService::handleEncryptedData(const uint8_t *data_bytes,uint32_t data_size,const TurtleFileHash& hash,const RsPeerId& virtual_peer_id) { #ifdef DEBUG_GXS_TUNNEL std::cerr << "p3GxsTunnelService::handleEncryptedDataItem()" << std::endl; std::cerr << " size = " << data_size << std::endl; std::cerr << " data = " << (void*)data_bytes << std::endl; std::cerr << " IV = " << std::hex << *(uint64_t*)data_bytes << std::dec << std::endl; std::cerr << " data = " << RsUtil::BinToHex((char*)data_bytes,data_size) ; std::cerr << std::endl; #endif RsGxsTunnelItem *citem = NULL; { RS_STACK_MUTEX(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ uint32_t encrypted_size = data_size - GXS_TUNNEL_ENCRYPTION_IV_SIZE - GXS_TUNNEL_ENCRYPTION_HMAC_SIZE; uint32_t decrypted_size = RsAES::get_buffer_size(encrypted_size); uint8_t *encrypted_data = (uint8_t*)data_bytes+GXS_TUNNEL_ENCRYPTION_IV_SIZE+GXS_TUNNEL_ENCRYPTION_HMAC_SIZE; uint8_t *decrypted_data = new uint8_t[decrypted_size]; uint8_t aes_key[GXS_TUNNEL_AES_KEY_SIZE] ; std::map::iterator it = _gxs_tunnel_virtual_peer_ids.find(virtual_peer_id) ; if(it == _gxs_tunnel_virtual_peer_ids.end()) { std::cerr << "(EE) item is not coming out of a registered tunnel. Weird. hash=" << hash << ", peer id = " << virtual_peer_id << std::endl; return true ; } RsGxsTunnelId tunnel_id = it->second.tunnel_id ; std::map::iterator it2 = _gxs_tunnel_contacts.find(tunnel_id) ; if(it2 == _gxs_tunnel_contacts.end()) { std::cerr << "(EE) no tunnel data for tunnel ID=" << tunnel_id << ". This is a bug." << std::endl; return true ; } memcpy(aes_key,it2->second.aes_key,GXS_TUNNEL_AES_KEY_SIZE) ; #ifdef DEBUG_GXS_TUNNEL std::cerr << " Using IV: " << std::hex << *(uint64_t*)data_bytes << std::dec << std::endl; std::cerr << " Decrypted buffer size: " << decrypted_size << std::endl; std::cerr << " key : " << RsUtil::BinToHex((char*)aes_key,GXS_TUNNEL_AES_KEY_SIZE) << std::endl; std::cerr << " hmac : " << RsUtil::BinToHex((char*)data_bytes+GXS_TUNNEL_ENCRYPTION_IV_SIZE,GXS_TUNNEL_ENCRYPTION_HMAC_SIZE) << std::endl; std::cerr << " data : " << RsUtil::BinToHex((char*)data_bytes,data_size) << std::endl; #endif // first, check the HMAC unsigned char *hm = HMAC(EVP_sha1(),aes_key,GXS_TUNNEL_AES_KEY_SIZE,encrypted_data,encrypted_size,NULL,NULL) ; if(memcmp(hm,&data_bytes[GXS_TUNNEL_ENCRYPTION_IV_SIZE],GXS_TUNNEL_ENCRYPTION_HMAC_SIZE)) { std::cerr << "(EE) packet HMAC does not match. Computed HMAC=" << RsUtil::BinToHex((char*)hm,GXS_TUNNEL_ENCRYPTION_HMAC_SIZE) << std::endl; std::cerr << "(EE) resetting new DH session." << std::endl; delete[] decrypted_data ; locked_restartDHSession(virtual_peer_id,it2->second.own_gxs_id) ; return false ; } if(!RsAES::aes_decrypt_8_16(encrypted_data,encrypted_size, aes_key,(uint8_t*)data_bytes,decrypted_data,decrypted_size)) { std::cerr << "(EE) packet decryption failed." << std::endl; std::cerr << "(EE) resetting new DH session." << std::endl; delete[] decrypted_data ; locked_restartDHSession(virtual_peer_id,it2->second.own_gxs_id) ; return false ; } it2->second.status = RS_GXS_TUNNEL_STATUS_CAN_TALK ; it2->second.last_contact = time(NULL) ; #ifdef DEBUG_GXS_TUNNEL std::cerr << "(II) Decrypted data: size=" << decrypted_size << std::endl; #endif // Now try deserialise the decrypted data to make an RsItem out of it. // citem = RsGxsTunnelSerialiser().deserialiseGxsTunnelItem(decrypted_data,&decrypted_size) ; delete[] decrypted_data ; if(citem == NULL) { std::cerr << "(EE) item could not be de-serialized. That is an error." << std::endl; return true; } // DH key items are sent even before we know who we speak to, so the virtual peer id is used in this // case only. citem->PeerId(virtual_peer_id) ; } #ifdef DEBUG_GXS_TUNNEL std::cerr << "(II) Setting peer id to " << citem->PeerId() << std::endl; #endif handleIncomingItem(citem) ; // Treats the item, and deletes it return true ; } void p3GxsTunnelService::handleRecvDHPublicKey(RsGxsTunnelDHPublicKeyItem *item) { if (!item) { std::cerr << "p3GxsTunnelService: Received null DH public key item. This should not happen." << std::endl; return; } #ifdef DEBUG_GXS_TUNNEL std::cerr << "GxsTunnelService: Received DH public key." << std::endl; item->print(std::cerr, 0) ; #endif // Look for the current state of the key agreement. TurtleVirtualPeerId vpid = item->PeerId() ; RS_STACK_MUTEX(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ std::map::iterator it = _gxs_tunnel_virtual_peer_ids.find(vpid) ; if(it == _gxs_tunnel_virtual_peer_ids.end()) { std::cerr << " (EE) Cannot find hash in gxs_tunnel peer list!!" << std::endl; return ; } // Now check the signature of the DH public key item. #ifdef DEBUG_GXS_TUNNEL std::cerr << " Checking signature. " << std::endl; #endif uint32_t pubkey_size = BN_num_bytes(item->public_key) ; unsigned char *data = (unsigned char *)malloc(pubkey_size) ; BN_bn2bin(item->public_key, data) ; RsTlvSecurityKey signature_key ; // We need to get the key of the sender, but if the key is not cached, we // need to get it first. So we let the system work for 2-3 seconds before // giving up. Normally this would only cause a delay for uncached keys, // which is rare. To force the system to cache the key, we first call for // getIdDetails(). // RsIdentityDetails details ; RsGxsId senders_id( item->signature.keyId ) ; for(int i=0;i<6;++i) if(!mGixs->getKey(senders_id,signature_key) || signature_key.keyData.bin_data == NULL) { #ifdef DEBUG_GXS_TUNNEL std::cerr << " Cannot get key. Waiting for caching. try " << i << "/6" << std::endl; #endif usleep(500 * 1000) ; // sleep for 500 msec. } else break ; if(signature_key.keyData.bin_data == NULL) { std::cerr << " (EE) Key unknown for checking signature from " << senders_id << ", can't verify signature. Using key provided in DH packet (without adding to the keyring)." << std::endl; // check GXS key for defects. if(!GxsSecurity::checkPublicKey(item->gxs_key)) { std::cerr << "(SS) Security error in distant chat DH handshake: supplied key " << item->gxs_key.keyId << " is inconsistent. Refusing chat!" << std::endl; return ; } if(item->gxs_key.keyId != item->signature.keyId) { std::cerr << "(SS) Security error in distant chat DH handshake: supplied key " << item->gxs_key.keyId << " is not the same than the item's signature key " << item->signature.keyId << ". Refusing chat!" << std::endl; return ; } signature_key = item->gxs_key ; } if(!GxsSecurity::validateSignature((char*)data,pubkey_size,signature_key,item->signature)) { std::cerr << "(SS) Signature was verified and it doesn't check! This is a security issue!" << std::endl; return ; } mGixs->timeStampKey(item->signature.keyId) ; #ifdef DEBUG_GXS_TUNNEL std::cerr << " Signature checks! Sender's ID = " << senders_id << std::endl; std::cerr << " Computing AES key" << std::endl; #endif if(it->second.dh == NULL) { std::cerr << " (EE) no DH information for that peer. This is an error." << std::endl; return ; } if(it->second.status == RS_GXS_TUNNEL_DH_STATUS_KEY_AVAILABLE) { #ifdef DEBUG_GXS_TUNNEL std::cerr << " DH Session already set for this tunnel. Re-initing a new session!" << std::endl; #endif locked_restartDHSession(vpid,it->second.own_gxs_id) ; } // gets current key params. By default, should contain all null pointers. // RsGxsId own_id = it->second.own_gxs_id ; RsGxsTunnelId tunnel_id = makeGxsTunnelId(own_id,senders_id) ; it->second.tunnel_id = tunnel_id ; it->second.gxs_id = senders_id ; // Looks for the DH params. If not there yet, create them. // int size = DH_size(it->second.dh) ; unsigned char *key_buff = new unsigned char[size] ; if(size != DH_compute_key(key_buff,item->public_key,it->second.dh)) { std::cerr << " (EE) DH computation failed. Probably a bug. Error code=" << ERR_get_error() << std::endl; return ; } it->second.status = RS_GXS_TUNNEL_DH_STATUS_KEY_AVAILABLE ; #ifdef DEBUG_GXS_TUNNEL std::cerr << " DH key computation successed. New key in place." << std::endl; #endif // make a hash of destination and source GXS ids in order to create the tunnel name GxsTunnelPeerInfo& pinfo(_gxs_tunnel_contacts[tunnel_id]) ; // Now hash the key buffer into a 16 bytes key. assert(GXS_TUNNEL_AES_KEY_SIZE <= Sha1CheckSum::SIZE_IN_BYTES) ; memcpy(pinfo.aes_key, RsDirUtil::sha1sum(key_buff,size).toByteArray(),GXS_TUNNEL_AES_KEY_SIZE) ; delete[] key_buff ; pinfo.last_contact = time(NULL) ; pinfo.last_keep_alive_sent = time(NULL) ; pinfo.status = RS_GXS_TUNNEL_STATUS_CAN_TALK ; pinfo.virtual_peer_id = vpid ; pinfo.direction = it->second.direction ; pinfo.own_gxs_id = own_id ; // note: the hash might still be nn initialised on server side. #ifdef DEBUG_GXS_TUNNEL std::cerr << " DH key computed. Tunnel is now secured!" << std::endl; std::cerr << " Key computed: " << RsUtil::BinToHex((char*)pinfo.aes_key,16) << std::cerr << std::endl; std::cerr << " Sending a ACK packet." << std::endl; #endif // then we send an ACK packet to notify that the tunnel works. That's useful // because it makes the peer at the other end of the tunnel know that all // intermediate peer in the tunnel are able to transmit the data. // However, it is not possible here to call sendTurtleData(), without dead-locking // the turtle router, so we store the item is a list of items to be sent. RsGxsTunnelStatusItem *cs = new RsGxsTunnelStatusItem ; cs->flags = RS_GXS_TUNNEL_FLAG_ACK_DISTANT_CONNECTION; cs->PeerId(vpid) ; pendingGxsTunnelItems.push_back(cs) ; #warning should notify client here //RsServer::notify()->notifyListChange(NOTIFY_LIST_PRIVATE_INCOMING_CHAT, NOTIFY_TYPE_ADD); } // Note: for some obscure reason, the typedef does not work here. Looks like a compiler error. So I use the primary type. GXSTunnelId p3GxsTunnelService::makeGxsTunnelId(const RsGxsId &own_id, const RsGxsId &distant_id) const // creates a unique ID from two GXS ids. { unsigned char mem[RsGxsId::SIZE_IN_BYTES * 2] ; // Always sort the ids, as a matter to avoid confusion between the two. Also that generates the same tunnel ID on both sides // which helps debugging. If the code is right this is not needed anyway. if(own_id < distant_id) { memcpy(mem, own_id.toByteArray(), RsGxsId::SIZE_IN_BYTES) ; memcpy(mem+RsGxsId::SIZE_IN_BYTES, distant_id.toByteArray(), RsGxsId::SIZE_IN_BYTES) ; } else { memcpy(mem, distant_id.toByteArray(), RsGxsId::SIZE_IN_BYTES) ; memcpy(mem+RsGxsId::SIZE_IN_BYTES, own_id.toByteArray(), RsGxsId::SIZE_IN_BYTES) ; } assert( RsGxsTunnelId::SIZE_IN_BYTES <= Sha1CheckSum::SIZE_IN_BYTES ) ; return RsGxsTunnelId( RsDirUtil::sha1sum(mem, 2*RsGxsId::SIZE_IN_BYTES).toByteArray() ) ; } bool p3GxsTunnelService::locked_sendDHPublicKey(const DH *dh,const RsGxsId& own_gxs_id,const RsPeerId& virtual_peer_id) { if(dh == NULL) { std::cerr << " (EE) DH struct is not initialised! Error." << std::endl; return false ; } RsGxsTunnelDHPublicKeyItem *dhitem = new RsGxsTunnelDHPublicKeyItem ; dhitem->public_key = BN_dup(dh->pub_key) ; // we should also sign the data and check the signature on the other end. // RsTlvKeySignature signature ; RsTlvSecurityKey signature_key ; RsTlvSecurityKey signature_key_public ; uint32_t error_status ; uint32_t size = BN_num_bytes(dhitem->public_key) ; unsigned char *data = (unsigned char *)malloc(size) ; BN_bn2bin(dhitem->public_key, data) ; if(!mGixs->signData((unsigned char*)data,size,own_gxs_id,signature,error_status)) { switch(error_status) { case RsGixs::RS_GIXS_ERROR_KEY_NOT_AVAILABLE: std::cerr << "(EE) Key is not available. Cannot sign." << std::endl; break ; default: std::cerr << "(EE) Unknown error when signing" << std::endl; break ; } free(data) ; delete(dhitem); return false; } free(data) ; if(!mGixs->getKey(own_gxs_id,signature_key_public)) { std::cerr << " (EE) Could not retrieve own public key for ID = " << own_gxs_id << ". Giging up sending DH session params." << std::endl; return false ; } assert(!(signature_key_public.keyFlags & RSTLV_KEY_TYPE_FULL)) ; dhitem->signature = signature ; dhitem->gxs_key = signature_key_public ; dhitem->PeerId(virtual_peer_id) ; #ifdef DEBUG_GXS_TUNNEL std::cerr << " Pushing DH session key item to pending distant messages..." << std::endl; dhitem->print(std::cerr, 2) ; std::cerr << std::endl; #endif pendingGxsTunnelItems.push_back(dhitem) ; // sent off-mutex to avoid deadlocking. return true ; } bool p3GxsTunnelService::locked_initDHSessionKey(DH *& dh) { // We use our own DH group prime. This has been generated with command-line openssl and checked. static const std::string dh_prime_2048_hex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if(dh != NULL) { DH_free(dh) ; dh = NULL ; } dh = DH_new() ; if(!dh) { std::cerr << " (EE) DH_new() failed." << std::endl; return false ; } BN_hex2bn(&dh->p,dh_prime_2048_hex.c_str()) ; BN_hex2bn(&dh->g,"5") ; int codes = 0 ; if(!DH_check(dh, &codes) || codes != 0) { std::cerr << " (EE) DH check failed!" << std::endl; return false ; } if(!DH_generate_key(dh)) { std::cerr << " (EE) DH generate_key() failed! Error code = " << ERR_get_error() << std::endl; return false ; } #ifdef DEBUG_GXS_TUNNEL std::cerr << " (II) DH Session key inited." << std::endl; #endif return true ; } // Encrypts and sends the item. void p3GxsTunnelService::sendTurtleData(RsGxsTunnelItem *item) { #ifdef DEBUG_GXS_TUNNEL std::cerr << "GxsTunnelService::sendTurtleData(): try sending item " << (void*)item << " to peer " << item->PeerId() << std::endl; #endif if(dynamic_cast(item) != NULL) { // make a TurtleGenericData item out of it, and send it in clear. // RsTurtleGenericDataItem *gitem = new RsTurtleGenericDataItem ; uint32_t rssize = item->serial_size() ; gitem->data_size = rssize + 8 ; gitem->data_bytes = malloc(rssize+8) ; // by convention, we use a IV of 0 for unencrypted data. memset(gitem->data_bytes,0,8) ; if(!item->serialise(&((uint8_t*)gitem->data_bytes)[8],rssize)) { std::cerr << "(EE) Could not serialise item!!!" << std::endl; delete gitem ; delete item ; return ; } #ifdef DEBUG_GXS_TUNNEL std::cerr << " GxsTunnelService::sendTurtleData(): Sending clear data to virtual peer: " << item->PeerId() << std::endl; std::cerr << " gitem->data_size = " << gitem->data_size << std::endl; std::cerr << " data = " << RsUtil::BinToHex((char*)gitem->data_bytes,gitem->data_size) ; std::cerr << std::endl; #endif mTurtle->sendTurtleData(item->PeerId(),gitem) ; } else { uint32_t rssize = item->serial_size(); uint8_t *buff = (uint8_t*)malloc(rssize) ; if(!item->serialise(buff,rssize)) { std::cerr << "(EE) GxsTunnelService::sendTurtleData(): Could not serialise item!" << std::endl; free(buff) ; delete item ; return ; } sendEncryptedTurtleData(buff,rssize,item->PeerId()) ; free(buff) ; } delete item ; } void p3GxsTunnelService::sendEncryptedTurtleData(const uint8_t *buff,uint32_t rssize,const TurtleVirtualPeerId& vpid) { uint8_t aes_key[GXS_TUNNEL_AES_KEY_SIZE] ; uint64_t IV = 0; #ifdef DEBUG_GXS_TUNNEL std::cerr << "Sending encrypted data to tunnel wuth vpid " << vpid << std::endl; #endif RsStackMutex stack(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ std::map::const_iterator it2 = _gxs_tunnel_virtual_peer_ids.find(vpid) ; if(it2 == _gxs_tunnel_virtual_peer_ids.end()) { std::cerr << "(EE) no virtual peer " << vpid << ". Something's wrong!" << std::endl; return ; } std::map::iterator it = _gxs_tunnel_contacts.find(it2->second.tunnel_id) ; if(it == _gxs_tunnel_contacts.end()) { std::cerr << "(EE) Cannot find contact key info for virtual peer id " << vpid << ". Cannot send message!" << std::endl; return ; } if(it->second.status != RS_GXS_TUNNEL_STATUS_CAN_TALK) { std::cerr << "(EE) Cannot talk to vpid " << vpid << ". Tunnel status is: " << it->second.status << std::endl; return ; } memcpy(aes_key,it->second.aes_key,GXS_TUNNEL_AES_KEY_SIZE) ; RsPeerId virtual_peer_id = it->second.virtual_peer_id ; while(IV == 0) IV = RSRandom::random_u64() ; // make a random 8 bytes IV, that is not 0 #ifdef DEBUG_GXS_TUNNEL std::cerr << "GxsTunnelService::sendTurtleData(): tunnel found. Encrypting data." << std::endl; #endif // Now encrypt this data using AES. // uint8_t *encrypted_data = new uint8_t[RsAES::get_buffer_size(rssize)]; uint32_t encrypted_size = RsAES::get_buffer_size(rssize); if(!RsAES::aes_crypt_8_16(buff,rssize,aes_key,(uint8_t*)&IV,encrypted_data,encrypted_size)) { std::cerr << "(EE) packet encryption failed." << std::endl; delete[] encrypted_data ; return ; } // make a TurtleGenericData item out of it: // RsTurtleGenericDataItem *gitem = new RsTurtleGenericDataItem ; gitem->data_size = encrypted_size + GXS_TUNNEL_ENCRYPTION_IV_SIZE + GXS_TUNNEL_ENCRYPTION_HMAC_SIZE ; gitem->data_bytes = malloc(gitem->data_size) ; memcpy(& ((uint8_t*)gitem->data_bytes)[0] ,&IV,8) ; unsigned int md_len = GXS_TUNNEL_ENCRYPTION_HMAC_SIZE ; HMAC(EVP_sha1(),aes_key,GXS_TUNNEL_AES_KEY_SIZE,encrypted_data,encrypted_size,&(((uint8_t*)gitem->data_bytes)[GXS_TUNNEL_ENCRYPTION_IV_SIZE]),&md_len) ; memcpy(& (((uint8_t*)gitem->data_bytes)[GXS_TUNNEL_ENCRYPTION_HMAC_SIZE+GXS_TUNNEL_ENCRYPTION_IV_SIZE]),encrypted_data,encrypted_size) ; delete[] encrypted_data ; #ifdef DEBUG_GXS_TUNNEL std::cerr << " Using IV: " << std::hex << IV << std::dec << std::endl; std::cerr << " Using Key: " << RsUtil::BinToHex((char*)aes_key,GXS_TUNNEL_AES_KEY_SIZE) ; std::cerr << std::endl; std::cerr << " hmac: " << RsUtil::BinToHex((char*)gitem->data_bytes,GXS_TUNNEL_ENCRYPTION_HMAC_SIZE) ; #endif #ifdef DEBUG_GXS_TUNNEL std::cerr << "GxsTunnelService::sendTurtleData(): Sending encrypted data to virtual peer: " << virtual_peer_id << std::endl; std::cerr << " gitem->data_size = " << gitem->data_size << std::endl; std::cerr << " serialised data = " << RsUtil::BinToHex((char*)gitem->data_bytes,gitem->data_size) ; std::cerr << std::endl; #endif mTurtle->sendTurtleData(virtual_peer_id,gitem) ; } bool p3GxsTunnelService::requestSecuredTunnel(const RsGxsId& to_gxs_id, const RsGxsId& from_gxs_id, RsGxsTunnelId &tunnel_id, uint32_t& error_code) { // should be a parameter. std::list lst ; mGixs->getOwnIds(lst) ; bool found = false ; for(std::list::const_iterator it = lst.begin();it!=lst.end();++it) if(*it == from_gxs_id) { found=true; break ; } if(!found) { std::cerr << " (EE) Cannot start distant chat, since GXS id " << from_gxs_id << " is not available." << std::endl; error_code = RS_GXS_TUNNEL_ERROR_UNKNOWN_GXS_ID ; return false ; } RsGxsId own_gxs_id = from_gxs_id ; startClientGxsTunnelConnection(to_gxs_id,own_gxs_id,tunnel_id) ; error_code = RS_GXS_TUNNEL_ERROR_NO_ERROR ; return true ; } void p3GxsTunnelService::startClientGxsTunnelConnection(const RsGxsId& to_gxs_id,const RsGxsId& from_gxs_id,RsGxsTunnelId& tunnel_id) { // compute a random hash for that pair, and init the DH session for it so that we can recognise it when we get the virtual peer for it. RsFileHash hash = randomHashFromDestinationGxsId(to_gxs_id) ; RsGxsTunnelId tnl_id = makeGxsTunnelId(from_gxs_id,to_gxs_id) ; tunnel_id = tnl_id ; { RsStackMutex stack(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ if(_gxs_tunnel_contacts.find(tunnel_id) != _gxs_tunnel_contacts.end()) { std::cerr << "GxsTunnelService:: asking GXS tunnel for a configuration that already exits.Ignoring." << std::endl; return ; } } GxsTunnelPeerInfo info ; time_t now = time(NULL) ; info.last_contact = now ; info.last_keep_alive_sent = now ; info.status = RS_GXS_TUNNEL_STATUS_TUNNEL_DN ; info.own_gxs_id = from_gxs_id ; info.to_gxs_id = to_gxs_id ; info.hash = hash ; info.direction = RsTurtleGenericTunnelItem::DIRECTION_SERVER ; info.virtual_peer_id.clear(); memset(info.aes_key,0,GXS_TUNNEL_AES_KEY_SIZE) ; { RsStackMutex stack(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ _gxs_tunnel_contacts[tunnel_id] = info ; } #ifdef DEBUG_GXS_TUNNEL std::cerr << "Starting distant chat to " << to_gxs_id << ", hash = " << hash << ", from " << from_gxs_id << std::endl; std::cerr << "Asking turtle router to monitor tunnels for hash " << hash << std::endl; #endif // Now ask the turtle router to manage a tunnel for that hash. mTurtle->monitorTunnels(hash,this,false) ; #warning check that this code should go. #ifdef TO_BE_REMOVED // spawn a status item so as to open the chat window. RsGxsTunnelMsgItem *item = new RsGxsTunnelMsgItem; item->message = "[Starting distant chat. Please wait for secure tunnel to be established]" ; item->chatFlags = RS_CHAT_FLAG_PRIVATE ; item->PeerId(RsPeerId(to_gxs_id)) ; handleRecvGxsTunnelMsgItem(item) ; #endif } TurtleFileHash p3GxsTunnelService::randomHashFromDestinationGxsId(const RsGxsId& destination) { // This is in prevision for the "secured GXS tunnel" service, which will need a service ID to register, // just like GRouter does. static const uint32_t client = RS_SERVICE_TYPE_GXS_TUNNEL ; assert( destination.SIZE_IN_BYTES == 16) ; assert(Sha1CheckSum::SIZE_IN_BYTES == 20) ; uint8_t bytes[20] ; memcpy(bytes,destination.toByteArray(),16) ; RAND_bytes(&bytes[16],4) ; // fill the last bytes with random crap. Very important to allow tunnels from different sources and statistically avoid collisions. // We could rehash this, with a secret key to get a HMAC. That would allow to publish secret distant chat // passphrases. I'll do this later if needed. return Sha1CheckSum(bytes) ; } RsGxsId p3GxsTunnelService::destinationGxsIdFromHash(const TurtleFileHash& sum) { assert( RsGxsId::SIZE_IN_BYTES == 16) ; assert(Sha1CheckSum::SIZE_IN_BYTES == 20) ; return RsGxsId(sum.toByteArray());// takes the first 16 bytes } bool p3GxsTunnelService::getTunnelStatus(const RsGxsTunnelId& tunnel_id,uint32_t& status) { RsStackMutex stack(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ std::map::const_iterator it = _gxs_tunnel_contacts.find(tunnel_id) ; if(it != _gxs_tunnel_contacts.end()) { status = it->second.status ; return true ; } status = RS_GXS_TUNNEL_STATUS_UNKNOWN ; return false ; } bool p3GxsTunnelService::closeExistingTunnel(const RsGxsTunnelId& tunnel_id) { // two cases: // - client needs to stop asking for tunnels => remove the hash from the list of tunnelled files // - server needs to only close the window and let the tunnel die. But the window should only open // if a message arrives. TurtleFileHash hash ; TurtleVirtualPeerId vpid ; { RsStackMutex stack(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ std::map::const_iterator it = _gxs_tunnel_contacts.find(tunnel_id) ; if(it == _gxs_tunnel_contacts.end()) { std::cerr << "(EE) Cannot close distant tunnel connection. No connection openned for tunnel id " << tunnel_id << std::endl; // We cannot stop tunnels, since their peer id is lost. Anyway, they'll die of starving. return false ; } vpid = it->second.virtual_peer_id ; if(it->second.direction == RsTurtleGenericTunnelItem::DIRECTION_CLIENT) // nothing more to do for server side. return true ; std::map::const_iterator it2 = _gxs_tunnel_virtual_peer_ids.find(vpid) ; if(it2 != _gxs_tunnel_virtual_peer_ids.end()) hash = it2->second.hash ; } // send a status item saying that we're closing the connection #ifdef DEBUG_GXS_TUNNEL std::cerr << " Sending a ACK to close the tunnel since we're managing it. tunnel id=." << tunnel_id << std::endl; #endif RsGxsTunnelStatusItem *cs = new RsGxsTunnelStatusItem ; cs->flags = RS_GXS_TUNNEL_FLAG_CLOSING_DISTANT_CONNECTION; cs->PeerId(vpid) ; sendTurtleData(cs) ; // that needs to be done off-mutex and before we close the tunnel. #ifdef DEBUG_GXS_TUNNEL std::cerr << " This is client side. Stopping tunnel manageement for tunnel_id " << tunnel_id << std::endl; #endif mTurtle->stopMonitoringTunnels( hash ) ; // still valid if the hash is null { RsStackMutex stack(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ std::map::iterator it = _gxs_tunnel_contacts.find(tunnel_id) ; if(it == _gxs_tunnel_contacts.end()) // server side. Nothing to do. { std::cerr << "(EE) Cannot close chat associated to tunnel id " << tunnel_id << ": not found." << std::endl; return false ; } _gxs_tunnel_contacts.erase(it) ; // GxsTunnelService::removeVirtualPeerId() will be called by the turtle service. } return true ; } void p3GxsTunnelService::markGxsTunnelAsClosed(const RsGxsTunnelId& tunnel_id) { RS_STACK_MUTEX(mGxsTunnelMtx); /********** STACK LOCKED MTX ******/ std::map::iterator it = _gxs_tunnel_contacts.find(tunnel_id) ; if(it == _gxs_tunnel_contacts.end()) { std::cerr << "(EE) Cannot mark distant chat connection as closed. No connection openned for tunnel id " << tunnel_id << ". Unexpected situation." << std::endl; return ; } if(it->second.direction == RsTurtleGenericDataItem::DIRECTION_CLIENT) { #ifdef DEBUG_GXS_TUNNEL std::cerr << " This is server side. Marking distant chat as remotely closed for tunnel id " << tunnel_id << std::endl; #endif it->second.status = RS_GXS_TUNNEL_STATUS_REMOTELY_CLOSED ; } }