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anti spoof for token protocol added

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east 2015-08-12 22:43:37 +02:00
parent a58ad6aef7
commit a2174bf179
3 changed files with 202 additions and 92 deletions
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18
src/engine/shared/network.h
View file

@ -178,6 +178,8 @@ private:
void ResendChunk(CNetChunkResend *pResend);
void Resend();
bool HasSecurityToken;
public:
bool m_TimeoutProtected;
bool m_TimeoutSituation;
@ -209,6 +211,9 @@ public:
int SeqSequence() const { return m_Sequence; }
int SecurityToken() const { return m_SecurityToken; }
void SetTimedOut(const NETADDR *pAddr, int Sequence, int Ack, SECURITY_TOKEN SecurityToken);
// anti spoof
void DirectInit(NETADDR &Addr, SECURITY_TOKEN SecurityToken);
};
class CConsoleNetConnection
@ -282,6 +287,14 @@ class CNetServer
CNetRecvUnpacker m_RecvUnpacker;
void OnTokenCtrlMsg(NETADDR &Addr, int ControlMsg, const CNetPacketConstruct &Packet);
void OnPreConnMsg(NETADDR &Addr, const CNetPacketConstruct &Packet);
bool ClientExists(const NETADDR &Addr);
void SendControl(NETADDR &Addr, int ControlMsg, const void *pExtra, int ExtraSize, SECURITY_TOKEN SecurityToken);
int TryAcceptClient(NETADDR &Addr, SECURITY_TOKEN SecurityToken);
int NumClientsWithAddr(NETADDR Addr);
public:
int SetCallbacks(NETFUNC_NEWCLIENT pfnNewClient, NETFUNC_DELCLIENT pfnDelClient, void *pUser);
@ -311,6 +324,9 @@ public:
int ResetErrorString(int ClientID);
const char *ErrorString(int ClientID);
// anti spoof
SECURITY_TOKEN GetToken(const NETADDR &Addr);
};
class CNetConsole
@ -405,6 +421,8 @@ public:
static void SendControlMsg(NETSOCKET Socket, NETADDR *pAddr, int Ack, int ControlMsg, const void *pExtra, int ExtraSize, SECURITY_TOKEN SecurityToken);
static void SendPacketConnless(NETSOCKET Socket, NETADDR *pAddr, const void *pData, int DataSize);
static void SendPacket(NETSOCKET Socket, NETADDR *pAddr, CNetPacketConstruct *pPacket, SECURITY_TOKEN SecurityToken);
static int UnpackPacket(unsigned char *pBuffer, int Size, CNetPacketConstruct *pPacket);
// The backroom is ack-NET_MAX_SEQUENCE/2. Used for knowing if we acked a packet or not

17
src/engine/shared/network_conn.cpp
View file

@ -203,6 +203,23 @@ void CNetConnection::Disconnect(const char *pReason)
Reset();
}
void CNetConnection::DirectInit(NETADDR &Addr, SECURITY_TOKEN SecurityToken)
{
Reset();
m_State = NET_CONNSTATE_ONLINE;
m_PeerAddr = Addr;
mem_zero(m_ErrorString, sizeof(m_ErrorString));
int64 Now = time_get();
m_LastSendTime = Now;
m_LastRecvTime = Now;
m_LastUpdateTime = Now;
m_SecurityToken = SecurityToken;
}
int CNetConnection::Feed(CNetPacketConstruct *pPacket, NETADDR *pAddr, SECURITY_TOKEN SecurityToken)
{
if (State() != NET_CONNSTATE_OFFLINE && m_SecurityToken != NET_SECURITY_TOKEN_UNKNOWN && m_SecurityToken != NET_SECURITY_TOKEN_UNSUPPORTED)

259
src/engine/shared/network_server.cpp
View file

@ -9,6 +9,11 @@
#include "network.h"
#include <engine/external/md5/md5.h>
static SECURITY_TOKEN ToSecurityToken(const unsigned char* pData)
{
return (int)pData[0] | (pData[1] << 8) | (pData[2] << 16) | (pData[3] << 24);
}
bool CNetServer::Open(NETADDR BindAddr, CNetBan *pNetBan, int MaxClients, int MaxClientsPerIP, int Flags)
{
// zero out the whole structure
@ -86,6 +91,148 @@ int CNetServer::Update()
return 0;
}
SECURITY_TOKEN CNetServer::GetToken(const NETADDR &Addr)
{
md5_state_t md5;
md5_byte_t digest[16];
SECURITY_TOKEN SecurityToken;
md5_init(&md5);
md5_append(&md5, (unsigned char*)m_SecurityTokenSeed, sizeof(m_SecurityTokenSeed));
md5_append(&md5, (unsigned char*)&Addr, sizeof(Addr));
md5_finish(&md5, digest);
SecurityToken = *(SECURITY_TOKEN*)digest;
if (SecurityToken == NET_SECURITY_TOKEN_UNKNOWN ||
SecurityToken == NET_SECURITY_TOKEN_UNSUPPORTED)
SecurityToken = 1;
return SecurityToken;
}
void CNetServer::SendControl(NETADDR &Addr, int ControlMsg, const void *pExtra, int ExtraSize, SECURITY_TOKEN SecurityToken)
{
CNetBase::SendControlMsg(m_Socket, &Addr, 0, ControlMsg, pExtra, ExtraSize, SecurityToken);
}
int CNetServer::NumClientsWithAddr(NETADDR Addr)
{
NETADDR ThisAddr = Addr, OtherAddr;
int FoundAddr = 0;
ThisAddr.port = 0;
for(int i = 0; i < MaxClients(); ++i)
{
if(m_aSlots[i].m_Connection.State() == NET_CONNSTATE_OFFLINE)
continue;
OtherAddr = *m_aSlots[i].m_Connection.PeerAddress();
OtherAddr.port = 0;
if(!net_addr_comp(&ThisAddr, &OtherAddr))
FoundAddr++;
}
return FoundAddr;
}
int CNetServer::TryAcceptClient(NETADDR &Addr, SECURITY_TOKEN SecurityToken)
{
// check for sv_max_clients_per_ip
if (NumClientsWithAddr(Addr) + 1 > m_MaxClientsPerIP)
{
char aBuf[128];
str_format(aBuf, sizeof(aBuf), "Only %d players with the same IP are allowed", m_MaxClientsPerIP);
CNetBase::SendControlMsg(m_Socket, &Addr, 0, NET_CTRLMSG_CLOSE, aBuf, sizeof(aBuf), SecurityToken);
return -1; // failed to add client
}
int Slot = -1;
for(int i = 0; i < MaxClients(); i++)
{
if(m_aSlots[i].m_Connection.State() == NET_CONNSTATE_OFFLINE)
{
Slot = i;
break;
}
}
if (Slot == -1)
{
const char FullMsg[] = "This server is full";
CNetBase::SendControlMsg(m_Socket, &Addr, 0, NET_CTRLMSG_CLOSE, FullMsg, sizeof(FullMsg), SecurityToken);
return -1; // failed to add client
}
// init connection slot
m_aSlots[Slot].m_Connection.DirectInit(Addr, SecurityToken);
if(m_pfnNewClient)
m_pfnNewClient(Slot, m_UserPtr);
return Slot; // done
}
void CNetServer::OnPreConnMsg(NETADDR &Addr, const CNetPacketConstruct &Packet)
{
dbg_msg("asd", "onpreconn");
}
void CNetServer::OnTokenCtrlMsg(NETADDR &Addr, int ControlMsg, const CNetPacketConstruct &Packet)
{
if (ClientExists(Addr))
return; // silently ignore
if (ControlMsg == NET_CTRLMSG_CONNECT)
{
bool SupportsToken = Packet.m_DataSize >=
(int)(1 + sizeof(SECURITY_TOKEN_MAGIC) + sizeof(SECURITY_TOKEN));
if (SupportsToken)
{
// response connection request with token
SECURITY_TOKEN Token = GetToken(Addr);
SendControl(Addr, NET_CTRLMSG_CONNECTACCEPT, SECURITY_TOKEN_MAGIC, sizeof(SECURITY_TOKEN_MAGIC), Token);
}
}
else if (ControlMsg == NET_CTRLMSG_ACCEPT && Packet.m_DataSize == 1 + sizeof(SECURITY_TOKEN))
{
SECURITY_TOKEN Token = ToSecurityToken(&Packet.m_aChunkData[1]);
if (Token == GetToken(Addr))
{
// correct token
// try to accept client
TryAcceptClient(Addr, Token);
}
else
{
// invalid token
if (g_Config.m_Debug)
dbg_msg("security", "invalid token");
}
}
}
bool CNetServer::ClientExists(const NETADDR &Addr)
{
for(int i = 0; i < MaxClients(); i++)
{
if(m_aSlots[i].m_Connection.State() != NET_CONNSTATE_OFFLINE &&
net_addr_comp(m_aSlots[i].m_Connection.PeerAddress(), &Addr) == 0)
{
// found
return true;
}
}
// doesn't exist
return false;
}
/*
TODO: chopp up this function into smaller working parts
*/
@ -130,106 +277,34 @@ int CNetServer::Recv(CNetChunk *pChunk)
}
else
{
// TODO: check size here
if(m_RecvUnpacker.m_Data.m_Flags&NET_PACKETFLAG_CONTROL && m_RecvUnpacker.m_Data.m_aChunkData[0] == NET_CTRLMSG_CONNECT)
// normal packet, find matching slot
bool Found = false;
for(int i = 0; i < MaxClients(); i++)
{
Found = false;
// check if we already got this client
for(int i = 0; i < MaxClients(); i++)
if(net_addr_comp(m_aSlots[i].m_Connection.PeerAddress(), &Addr) == 0)
{
if(m_aSlots[i].m_Connection.State() != NET_CONNSTATE_OFFLINE &&
m_aSlots[i].m_Connection.State() != NET_CONNSTATE_ERROR &&
net_addr_comp(m_aSlots[i].m_Connection.PeerAddress(), &Addr) == 0)
{
Found = true; // silent ignore.. we got this client already
//if(m_aSlots[i].m_Connection.State() == NET_CONNSTATE_ERROR)
//{
// m_aSlots[i].m_Connection.Feed(&m_RecvUnpacker.m_Data, &Addr);
// if(m_pfnNewClient)
// m_pfnNewClient(i, m_UserPtr);
//}
break;
}
}
if(m_aSlots[i].m_Connection.State() == NET_CONNSTATE_OFFLINE ||
m_aSlots[i].m_Connection.State() == NET_CONNSTATE_ERROR)
continue;
// client that wants to connect
if(!Found)
{
// only allow a specific number of players with the same ip
NETADDR ThisAddr = Addr, OtherAddr;
int FoundAddr = 1;
ThisAddr.port = 0;
for(int i = 0; i < MaxClients(); ++i)
Found = true;
if(m_aSlots[i].m_Connection.Feed(&m_RecvUnpacker.m_Data, &Addr))
{
if(m_aSlots[i].m_Connection.State() == NET_CONNSTATE_OFFLINE)
continue;
OtherAddr = *m_aSlots[i].m_Connection.PeerAddress();
OtherAddr.port = 0;
if(!net_addr_comp(&ThisAddr, &OtherAddr))
{
if(FoundAddr++ >= m_MaxClientsPerIP)
{
char aBuf[128];
str_format(aBuf, sizeof(aBuf), "Only %d players with the same IP are allowed", m_MaxClientsPerIP);
CNetBase::SendControlMsg(m_Socket, &Addr, 0, NET_CTRLMSG_CLOSE, aBuf, sizeof(aBuf), NET_SECURITY_TOKEN_UNSUPPORTED);
return 0;
}
}
}
for(int i = 0; i < MaxClients(); i++)
{
if(m_aSlots[i].m_Connection.State() == NET_CONNSTATE_OFFLINE)
{
Found = true;
long timestamp = time_get();
md5_state_t md5;
md5_byte_t digest[16];
SECURITY_TOKEN securityToken;
do
{
md5_init(&md5);
md5_append(&md5, (unsigned char*)m_SecurityTokenSeed, sizeof(m_SecurityTokenSeed));
md5_append(&md5, (unsigned char*)&Addr, sizeof(Addr));
md5_append(&md5, (unsigned char*)&timestamp, sizeof(timestamp));
md5_finish(&md5, digest);
securityToken = ToSecurityToken(digest);
timestamp++;
}
while (securityToken == NET_SECURITY_TOKEN_UNKNOWN || securityToken == NET_SECURITY_TOKEN_UNSUPPORTED);
m_aSlots[i].m_Connection.Feed(&m_RecvUnpacker.m_Data, &Addr, securityToken);
if(m_pfnNewClient)
m_pfnNewClient(i, m_UserPtr);
break;
}
}
if(!Found)
{
const char FullMsg[] = "This server is full";
CNetBase::SendControlMsg(m_Socket, &Addr, 0, NET_CTRLMSG_CLOSE, FullMsg, sizeof(FullMsg), NET_SECURITY_TOKEN_UNSUPPORTED);
if(m_RecvUnpacker.m_Data.m_DataSize)
m_RecvUnpacker.Start(&Addr, &m_aSlots[i].m_Connection, i);
}
}
}
else
if (!Found)
{
// normal packet, find matching slot
for(int i = 0; i < MaxClients(); i++)
{
if(net_addr_comp(m_aSlots[i].m_Connection.PeerAddress(), &Addr) == 0)
{
if(m_aSlots[i].m_Connection.State() == NET_CONNSTATE_OFFLINE ||
m_aSlots[i].m_Connection.State() == NET_CONNSTATE_ERROR)
continue;
if(m_aSlots[i].m_Connection.Feed(&m_RecvUnpacker.m_Data, &Addr))
{
if(m_RecvUnpacker.m_Data.m_DataSize)
m_RecvUnpacker.Start(&Addr, &m_aSlots[i].m_Connection, i);
}
}
}
if(m_RecvUnpacker.m_Data.m_Flags&NET_PACKETFLAG_CONTROL &&
m_RecvUnpacker.m_Data.m_DataSize > 1)
// got control msg with extra size (should support token)
OnTokenCtrlMsg(Addr, m_RecvUnpacker.m_Data.m_aChunkData[0], m_RecvUnpacker.m_Data);
else
// got connection-less ctrl or sys msg
OnPreConnMsg(Addr, m_RecvUnpacker.m_Data);
}
}
}