void Handshake::createCookie(PacketWriter& writer,HelloAttempt& attempt,const string& tag,const string& queryUrl) {
// New Cookie
Cookie* pCookie = attempt.pCookie;
if(!pCookie) {
if(attempt.pTarget)
pCookie = new Cookie(*this,invoker,tag,*attempt.pTarget);
else
pCookie = new Cookie(*this,invoker,tag,queryUrl);
_cookies[pCookie->value()] = pCookie;
attempt.pCookie = pCookie;
}
writer.write8(COOKIE_SIZE);
writer.writeRaw(pCookie->value(),COOKIE_SIZE);
}
void RTMFP::Encode(AESEngine& aesEncrypt,PacketWriter& packet) {
if(aesEncrypt.type != AESEngine::EMPTY) {
// paddingBytesLength=(0xffffffff-plainRequestLength+5)&0x0F
int paddingBytesLength = (0xFFFFFFFF-packet.length()+5)&0x0F;
// Padd the plain request with paddingBytesLength of value 0xff at the end
packet.reset(packet.length());
string end(paddingBytesLength,(UInt8)0xFF);
packet.writeRaw(end);
}
WriteCRC(packet);
// Encrypt the resulted request
aesEncrypt.process(packet.begin()+4,packet.begin()+4,packet.length()-4);
}
void RTMFP::Encode(AESEngine& aesEncrypt,PacketWriter packet) {
// paddingBytesLength=(0xffffffff-plainRequestLength+5)&0x0F
int paddingBytesLength = (0xFFFFFFFF-packet.length()+5)&0x0F;
// Padd the plain request with paddingBytesLength of value 0xff at the end
packet.reset(packet.length());
string end(paddingBytesLength,(UInt8)0xFF);
packet.writeRaw(end);
// Compute the CRC and add it at the beginning of the request
PacketReader reader(packet);
reader.next(6);
UInt16 sum = CheckSum(reader);
packet.reset(4);packet << sum;
// Encrypt the resulted request
reader.reset(4);
aesEncrypt.process(reader.current(),reader.current(),reader.available());
}
// TODO make perhaps a FlowHandshake
UInt8 Handshake::handshakeHandler(UInt8 id,PacketReader& request,PacketWriter& response) {
switch(id){
case 0x30: {
request.read8(); // passer un caractere (boite dans boite)
UInt8 epdLen = request.read8()-1;
UInt8 type = request.read8();
string epd;
request.readRaw(epdLen,epd);
string tag;
request.readRaw(16,tag);
response.writeString8(tag);
// UDP hole punching
if(type == 0x0f)
return _gateway.p2pHandshake(tag,response,peer().address,(const UInt8*)epd.c_str());
if(type == 0x0a){
/// Handshake
// RESPONSE 38
// New Cookie
char cookie[65];
RandomInputStream ris;
ris.read(cookie,64);
cookie[64]='\0';
response.write8(64);
response.writeRaw(cookie,64);
_cookies[cookie] = new Cookie(epd);
// instance id (certificat in the middle)
response.writeRaw(_certificat,sizeof(_certificat));
return 0x70;
} else {
ERROR("Unkown handshake first way with '%02x' type",type);
}
break;
}
case 0x38: {
_farId = request.read32();
string cookie;
request.readRaw(request.read8(),cookie);
map<string,Cookie*>::iterator itCookie = _cookies.find(cookie.c_str());
if(itCookie==_cookies.end()) {
ERROR("Handshake cookie '%s' unknown",cookie.c_str());
return 0;
}
request.read8(); // why 0x81?
// signature
string farSignature;
request.readString8(farSignature); // 81 02 1D 02 stable
// farPubKeyPart
UInt8 farPubKeyPart[128];
request.readRaw((char*)farPubKeyPart,sizeof(farPubKeyPart));
string farCertificat;
request.readString8(farCertificat);
// peerId = SHA256(farSignature+farPubKey)
string temp(farSignature);
temp.append((char*)farPubKeyPart,sizeof(farPubKeyPart));
EVP_Digest(temp.c_str(),temp.size(),(UInt8*)peer().id,NULL,EVP_sha256(),NULL);
// Compute Diffie-Hellman secret
UInt8 pubKey[128];
UInt8 sharedSecret[128];
RTMFP::EndDiffieHellman(RTMFP::BeginDiffieHellman(pubKey),farPubKeyPart,sharedSecret);
// Compute Keys
UInt8 requestKey[AES_KEY_SIZE];
UInt8 responseKey[AES_KEY_SIZE];
RTMFP::ComputeAsymetricKeys(sharedSecret,pubKey,_signature,farCertificat,requestKey,responseKey);
// RESPONSE
Util::UnpackUrl(itCookie->second->queryUrl,(string&)peer().path,(map<string,string>&)peer().parameters);
response << _gateway.createSession(_farId,peer(),requestKey,responseKey);
response.write8(0x81);
response.writeString8(_signature);
response.writeRaw((char*)pubKey,sizeof(pubKey));
response.write8(0x58);
// remove cookie
_cookies.erase(itCookie);
// db_add_public(s); // TODO
return 0x78;
}
default:
ERROR("Unkown handshake packet id '%02x'",id);
}
return 0;
}
UInt8 RTMFPServer::p2pHandshake(const string& tag,PacketWriter& response,const SocketAddress& address,const UInt8* peerIdWanted) {
ServerSession* pSessionWanted = (ServerSession*)_sessions.find(peerIdWanted);
if(_pCirrus) {
// Just to make working the man in the middle mode !
// find the flash client equivalence
Session* pSession = _sessions.find(address);
if(!pSession) {
ERROR("UDP Hole punching error : middle equivalence not found for session wanted");
return 0;
}
PacketWriter& request = ((Middle*)pSession)->handshaker();
request.write8(0x22);
request.write8(0x21);
request.write8(0x0F);
request.writeRaw(pSessionWanted ? ((Middle*)pSessionWanted)->middlePeer().id : peerIdWanted,ID_SIZE);
request.writeRaw(tag);
((Middle*)pSession)->sendHandshakeToTarget(0x30);
// no response here!
return 0;
}
if(!pSessionWanted) {
DEBUG("UDP Hole punching : session %s wanted not found",Util::FormatHex(peerIdWanted,ID_SIZE).c_str())
set<string> addresses;
onRendezVousUnknown(peerIdWanted,addresses);
if(addresses.empty())
return 0;
set<string>::const_iterator it;
for(it=addresses.begin(); it!=addresses.end(); ++it) {
try {
SocketAddress address(*it);
response.writeAddress(address,it==addresses.begin());
} catch(Exception& ex) {
ERROR("Bad redirection address %s, %s",(*it).c_str(),ex.displayText().c_str());
}
}
return 0x71;
} else if(pSessionWanted->failed()) {
DEBUG("UDP Hole punching : session wanted is deleting");
return 0;
}
UInt8 result = 0x00;
if(_middle) {
if(pSessionWanted->pTarget) {
HelloAttempt& attempt = _handshake.helloAttempt<HelloAttempt>(tag);
attempt.pTarget = pSessionWanted->pTarget;
_handshake.createCookie(response,attempt,tag,"");
response.writeRaw(&pSessionWanted->pTarget->publicKey[0],pSessionWanted->pTarget->publicKey.size());
result = 0x70;
} else
ERROR("Peer/peer dumped exchange impossible : no corresponding 'Target' with the session wanted");
}
if(result==0x00) {
/// Udp hole punching normal process
UInt32 times = pSessionWanted->helloAttempt(tag);
pSessionWanted->p2pHandshake(address,tag,times,(times>0 || address.host()==pSessionWanted->peer.address.host()) ? _sessions.find(address) : NULL);
bool first=true;
list<Address>::const_iterator it2;
for(it2=pSessionWanted->peer.addresses.begin(); it2!=pSessionWanted->peer.addresses.end(); ++it2) {
const Address& addr = *it2;
if(addr == address)
WARN("A client tries to connect to himself (same %s address)",address.toString().c_str());
response.writeAddress(addr,first);
DEBUG("P2P address initiator exchange, %s:%u",Util::FormatHex(&addr.host[0],addr.host.size()).c_str(),addr.port);
first=false;
}
result = 0x71;
}
return result;
}
UInt8 Handshake::handshakeHandler(UInt8 id,PacketReader& request,PacketWriter& response) {
switch(id){
case 0x30: {
request.read8(); // passer un caractere (boite dans boite)
UInt8 epdLen = request.read8()-1;
UInt8 type = request.read8();
string epd;
request.readRaw(epdLen,epd);
string tag;
request.readRaw(16,tag);
response.writeString8(tag);
if(type == 0x0f)
return _gateway.p2pHandshake(tag,response,peer.address,(const UInt8*)epd.c_str());
if(type == 0x0a){
/// Handshake
HelloAttempt& attempt = helloAttempt<HelloAttempt>(tag);
// Fill peer infos
UInt16 port;
string host;
Util::UnpackUrl(epd,host,port,(string&)peer.path,(map<string,string>&)peer.properties);
set<string> addresses;
peer.onHandshake(attempt.count+1,addresses);
if(!addresses.empty()) {
set<string>::iterator it;
for(it=addresses.begin();it!=addresses.end();++it) {
try {
if((*it)=="again")
((string&)*it).assign(format("%s:%hu",host,port));
SocketAddress address(*it);
response.writeAddress(address,it==addresses.begin());
} catch(Exception& ex) {
ERROR("Bad redirection address %s in hello attempt, %s",(*it)=="again" ? epd.c_str() : (*it).c_str(),ex.displayText().c_str());
}
}
return 0x71;
}
// New Cookie
createCookie(response,attempt,tag,epd);
// instance id (certificat in the middle)
response.writeRaw(_certificat,sizeof(_certificat));
return 0x70;
} else
ERROR("Unkown handshake first way with '%02x' type",type);
break;
}
case 0x38: {
(UInt32&)farId = request.read32();
if(request.read7BitLongValue()!=COOKIE_SIZE) {
ERROR("Bad handshake cookie '%s': its size should be 64 bytes",Util::FormatHex(request.current(),COOKIE_SIZE).c_str());
return 0;
}
map<const UInt8*,Cookie*,CompareCookies>::iterator itCookie = _cookies.find(request.current());
if(itCookie==_cookies.end()) {
WARN("Cookie %s unknown, maybe already connected (udpBuffer congested?)",Util::FormatHex(request.current(),COOKIE_SIZE).c_str());
return 0;
}
Cookie& cookie(*itCookie->second);
(SocketAddress&)cookie.peerAddress = peer.address;
if(cookie.farId==0) {
((UInt32&)cookie.farId) = farId;
request.next(COOKIE_SIZE);
size_t size = (size_t)request.read7BitLongValue();
// peerId = SHA256(farPubKey)
EVP_Digest(request.current(),size,(UInt8*)cookie.peerId,NULL,EVP_sha256(),NULL);
cookie.initiatorKey().resize(request.read7BitValue()-2);
request.next(2); // unknown
request.readRaw(&cookie.initiatorKey()[0],cookie.initiatorKey().size());
cookie.initiatorNonce().resize(request.read7BitValue());
request.readRaw(&cookie.initiatorNonce()[0],cookie.initiatorNonce().size());
cookie.computeKeys();
} else if(cookie.id>0) {
// Repeat cookie reponse!
cookie.read(response);
return 0x78;
} // else Keys are computing (multi-thread)
break;
}
default:
ERROR("Unkown handshake packet id %u",id);
}
return 0;
}
UInt8 Handshake::handshakeHandler(UInt8 id,PacketReader& request,PacketWriter& response) {
switch(id){
case 0x30: {
request.read8(); // passer un caractere (boite dans boite)
UInt8 epdLen = request.read8()-1;
UInt8 type = request.read8();
string epd;
request.readRaw(epdLen,epd);
string tag;
request.readRaw(16,tag);
response.writeString8(tag);
if(type == 0x0f)
return _gateway.p2pHandshake(tag,response,peer.address,(const UInt8*)epd.c_str());
if(type == 0x0a){
/// Handshake
HelloAttempt& attempt = helloAttempt<HelloAttempt>(tag);
if(edges().size()>0 && (_invoker.edgesAttemptsBeforeFallback==0 || attempt.count <_invoker.edgesAttemptsBeforeFallback)) {
if(_invoker.edgesAttemptsBeforeFallback>0) {
try {
URI uri(epd);
response.writeAddress(SocketAddress(uri.getHost(),uri.getPort()),false); // TODO check with true!
} catch(Exception& ex) {
ERROR("Parsing %s URL problem in hello attempt : %s",epd.c_str(),ex.displayText().c_str());
}
}
map<int,list<Edge*> > edgesSortedByCount;
map<string,Edge*>::const_iterator it;
for(it=edges().begin();it!=edges().end();++it)
edgesSortedByCount[it->second->count].push_back(it->second);
UInt8 count=0;
map<int,list<Edge*> >::const_iterator it2;
for(it2=edgesSortedByCount.begin();it2!=edgesSortedByCount.end();++it2) {
list<Edge*>::const_iterator it3;
for(it3=it2->second.begin();it3!=it2->second.end();++it3) {
response.writeAddress((*it3)->address,false);
if((++count)==6) // 6 redirections maximum
break;
}
if(it3!=it2->second.end())
break;
}
return 0x71;
}
if(edges().size()>0)
WARN("After %u hello attempts, impossible to connect to edges. Edges are busy? or unreachable?",_invoker.edgesAttemptsBeforeFallback);
// New Cookie
createCookie(response,attempt,tag,epd);
// instance id (certificat in the middle)
response.writeRaw(_certificat,sizeof(_certificat));
return 0x70;
} else
ERROR("Unkown handshake first way with '%02x' type",type);
break;
}
case 0x39:
case 0x38: {
(UInt32&)farId = request.read32();
if(request.read7BitLongValue()!=COOKIE_SIZE) {
ERROR("Bad handshake cookie '%s': its size should be 64 bytes",Util::FormatHex(request.current(),COOKIE_SIZE).c_str());
return 0;
}
map<const UInt8*,Cookie*,CompareCookies>::iterator itCookie = _cookies.find(request.current());
if(itCookie==_cookies.end()) {
if(id!=0x39) {
ERROR("Handshake cookie '%s' unknown",Util::FormatHex(request.current(),COOKIE_SIZE).c_str());
return 0;
}
Cookie* pCookie = new Cookie();
UInt32 pos = request.position();
request.readRaw((UInt8*)pCookie->value,COOKIE_SIZE);
request >> (string&)pCookie->queryUrl;
request.reset(pos);
itCookie = _cookies.insert(pair<const UInt8*,Cookie*>(pCookie->value,pCookie)).first;
}
Cookie& cookie(*itCookie->second);
if(cookie.id==0) {
UInt8 decryptKey[AES_KEY_SIZE];UInt8* pDecryptKey=&decryptKey[0];
UInt8 encryptKey[AES_KEY_SIZE];UInt8* pEncryptKey=&encryptKey[0];
if(id==0x38) {
request.next(COOKIE_SIZE);
size_t size = (size_t)request.read7BitLongValue();
// peerId = SHA256(farPubKey)
EVP_Digest(request.current(),size,(UInt8*)peer.id,NULL,EVP_sha256(),NULL);
vector<UInt8> publicKey(request.read7BitValue()-2);
request.next(2); // unknown
request.readRaw(&publicKey[0],publicKey.size());
size = request.read7BitValue();
cookie.computeKeys(&publicKey[0],publicKey.size(),request.current(),(UInt16)size,decryptKey,encryptKey);
} else {
// edge
pDecryptKey=NULL;
pEncryptKey=NULL;
memcpy((UInt8*)peer.id,request.current(),ID_SIZE);
request.next(COOKIE_SIZE);
request.next(request.read7BitEncoded());
}
// Fill peer infos
Util::UnpackUrl(cookie.queryUrl,(string&)peer.path,(map<string,string>&)peer.properties);
// RESPONSE
Session& session = _gateway.createSession(farId,peer,pDecryptKey,pEncryptKey,cookie);
(UInt32&)cookie.id = session.id;
string address;
if(id==0x39) {
// Session by edge
session.flags |= SESSION_BY_EDGE;
Edge* pEdge = _invoker.edges(peer.address);
if(!pEdge)
ERROR("Edge session creation by an unknown server edge %s",peer.address.toString().c_str())
else
pEdge->addSession(session);
request >> address;
} else // Session direct
address = session.peer.address.toString();
session.peer.addresses.clear();
session.peer.addresses.push_back(address);
cookie.write();
} else