private void CreateUserHash()
{
for (int i = 0; i < 8; i++)
{
ushort random = MpdUtilities.GetRandomUInt16();
Array.Copy(BitConverter.GetBytes(random), 0,
UserHash_, i * 2, 2);
}
// mark as emule client. that will be need in later version
UserHash_[5] = 14;
UserHash_[14] = 111;
}
public virtual int EncryptSendServer(ref byte[] ppbyBuf, int nBufLen, uint dwBaseKey)
{
Debug.Assert(MuleApplication.Instance.Preference.IsServerCryptLayerUDPEnabled);
Debug.Assert(dwBaseKey != 0);
byte byPadLen = 0; // padding disabled for UDP currently
int nCryptedLen = nBufLen + byPadLen + CRYPT_HEADER_WITHOUTPADDING;
byte[] pachCryptedBuffer = new byte[nCryptedLen];
ushort nRandomKeyPart = MpdUtilities.GetRandomUInt16();
byte[] achKeyData = new byte[7];
Array.Copy(BitConverter.GetBytes(dwBaseKey), achKeyData, 4);
achKeyData[4] = MAGICVALUE_UDP_CLIENTSERVER;
Array.Copy(BitConverter.GetBytes(nRandomKeyPart), 0, achKeyData, 5, 2);
MD5 md5 = MD5.Create();
byte[] rawHash = md5.ComputeHash(achKeyData);
RC4Key keySendKey = null;
MuleUtilities.RC4CreateKey(rawHash, 16, ref keySendKey, true);
// create the semi random byte encryption header
byte bySemiRandomNotProtocolMarker = 0;
int i;
for (i = 0; i < 128; i++)
{
bySemiRandomNotProtocolMarker = MpdUtilities.GetRandomUInt8();
if (bySemiRandomNotProtocolMarker != MuleConstants.PROTOCOL_EDONKEYPROT) // not allowed values
{
break;
}
}
if (i >= 128)
{
// either we have _real_ bad luck or the randomgenerator is a bit messed up
Debug.Assert(false);
bySemiRandomNotProtocolMarker = 0x01;
}
uint dwMagicValue = MAGICVALUE_UDP_SYNC_SERVER;
pachCryptedBuffer[0] = bySemiRandomNotProtocolMarker;
Array.Copy(BitConverter.GetBytes(nRandomKeyPart), 0, pachCryptedBuffer, 1, 2);
MuleUtilities.RC4Crypt(BitConverter.GetBytes(dwMagicValue), 0,
pachCryptedBuffer, 3, 4, keySendKey);
MuleUtilities.RC4Crypt(new byte[] { byPadLen }, 0, pachCryptedBuffer, 7, 1, keySendKey);
Random rand = new Random();
for (int j = 0; j < byPadLen; j++)
{
byte byRand = (byte)rand.Next(255); // they actually dont really need to be random, but it doesn't hurts either
MuleUtilities.RC4Crypt(new byte[] { byRand }, 0,
pachCryptedBuffer, CRYPT_HEADER_WITHOUTPADDING + j, 1, keySendKey);
}
MuleUtilities.RC4Crypt(ppbyBuf, 0,
pachCryptedBuffer, CRYPT_HEADER_WITHOUTPADDING + byPadLen, (uint)nBufLen, keySendKey);
ppbyBuf = pachCryptedBuffer;
MuleApplication.Instance.Statistics.AddUpDataOverheadCrypt((uint)(nCryptedLen - nBufLen));
return(nCryptedLen);
}
private bool ProcessPacket(byte[] buffer, int offset, int size, uint opcode, uint nIP, ushort nUDPPort)
{
try
{
MuleApplication.Instance.Statistics.AddDownDataOverheadServer((uint)size);
ED2KServer pServer = MuleApplication.Instance.ServerList.GetServerByIPUDP(nIP, nUDPPort, true);
if (pServer != null)
{
pServer.ResetFailedCount();
}
switch ((OperationCodeEnum)opcode)
{
case OperationCodeEnum.OP_GLOBSEARCHRES:
{
SafeMemFile data = MpdObjectManager.CreateSafeMemFile(buffer, size);
// process all search result packets
int iLeft;
do
{
uint uResultCount = MuleApplication.Instance.SearchList.ProcessUDPSearchAnswer(data, true /*pServer.GetUnicodeSupport()*/, nIP, nUDPPort - 4);
// check if there is another source packet
iLeft = (int)(data.Length - data.Position);
if (iLeft >= 2)
{
byte protocol = data.ReadUInt8();
iLeft--;
if (protocol != MuleConstants.PROTOCOL_EDONKEYPROT)
{
data.Seek(-1, System.IO.SeekOrigin.Current);
iLeft += 1;
break;
}
byte opcode1 = data.ReadUInt8();
iLeft--;
if (opcode1 != (byte)OperationCodeEnum.OP_GLOBSEARCHRES)
{
data.Seek(-2, System.IO.SeekOrigin.Current);
iLeft += 2;
break;
}
}
}while (iLeft > 0);
break;
}
case OperationCodeEnum.OP_GLOBFOUNDSOURCES:
{
SafeMemFile data = MpdObjectManager.CreateSafeMemFile(buffer, size);
// process all source packets
int iLeft;
do
{
byte[] fileid = new byte[16];
data.ReadHash16(fileid);
PartFile file = MuleApplication.Instance.DownloadQueue.GetFileByID(fileid);
if (file != null)
{
file.AddSources(data, nIP, (ushort)(nUDPPort - 4), false);
}
else
{
// skip sources for that file
uint count = data.ReadUInt8();
data.Seek(count * (4 + 2), System.IO.SeekOrigin.Current);
}
// check if there is another source packet
iLeft = (int)(data.Length - data.Position);
if (iLeft >= 2)
{
byte protocol = data.ReadUInt8();
iLeft--;
if (protocol != MuleConstants.PROTOCOL_EDONKEYPROT)
{
data.Seek(-1, System.IO.SeekOrigin.Current);
iLeft += 1;
break;
}
byte opcode1 = data.ReadUInt8();
iLeft--;
if (opcode1 != (byte)OperationCodeEnum.OP_GLOBFOUNDSOURCES)
{
data.Seek(-2, System.IO.SeekOrigin.Current);
iLeft += 2;
break;
}
}
}while (iLeft > 0);
break;
}
case OperationCodeEnum.OP_GLOBSERVSTATRES:
{
if (size < 12 || pServer == null)
{
return(true);
}
uint challenge = BitConverter.ToUInt32(buffer, 0);
if (challenge != pServer.Challenge)
{
return(true);
}
if (pServer != null)
{
pServer.Challenge = 0;
pServer.CryptPingReplyPending = false;
uint tNow = MpdUtilities.Time();
Random rand = new Random();
// if we used Obfuscated ping, we still need to reset the time properly
pServer.LastPingedTime =
Convert.ToUInt32(tNow - (rand.Next() % MuleConstants.ONE_HOUR_SEC));
}
uint cur_user = BitConverter.ToUInt32(buffer, 4);
uint cur_files = BitConverter.ToUInt32(buffer, 8);
uint cur_maxusers = 0;
uint cur_softfiles = 0;
uint cur_hardfiles = 0;
uint uUDPFlags = 0;
uint uLowIDUsers = 0;
uint dwServerUDPKey = 0;
ushort nTCPObfuscationPort = 0;
ushort nUDPObfuscationPort = 0;
if (size >= 16)
{
cur_maxusers = BitConverter.ToUInt32(buffer, 12);
}
if (size >= 24)
{
cur_softfiles = BitConverter.ToUInt32(buffer, 16);
cur_hardfiles = BitConverter.ToUInt32(buffer, 20);
}
if (size >= 28)
{
uUDPFlags = BitConverter.ToUInt32(buffer, 24);
}
if (size >= 32)
{
uLowIDUsers = BitConverter.ToUInt32(buffer, 28);
}
if (size >= 40)
{
// TODO debug check if this packet was encrypted if it has a key
nUDPObfuscationPort = BitConverter.ToUInt16(buffer, 32);
nTCPObfuscationPort = BitConverter.ToUInt16(buffer, 34);;
dwServerUDPKey = BitConverter.ToUInt32(buffer, 36);
}
if (pServer != null)
{
pServer.Ping = MpdUtilities.GetTickCount() - pServer.LastPinged;
pServer.UserCount = cur_user;
pServer.FileCount = cur_files;
pServer.MaxUsers = cur_maxusers;
pServer.SoftFiles = cur_softfiles;
pServer.HardFiles = cur_hardfiles;
pServer.ServerKeyUDP = dwServerUDPKey;
pServer.ObfuscationPortTCP = nTCPObfuscationPort;
pServer.ObfuscationPortUDP = nUDPObfuscationPort;
// if the received UDP flags do not match any already stored UDP flags,
// reset the server version string because the version (which was determined by last connecting to
// that server) is most likely not accurat any longer.
// this may also give 'false' results because we don't know the UDP flags when connecting to a server
// with TCP.
//if (pServer.GetUDPFlags() != uUDPFlags)
// pServer.Version(_T = "");
pServer.UDPFlags = (ED2KServerUdpFlagsEnum)uUDPFlags;
pServer.LowIDUsers = uLowIDUsers;
pServer.SetLastDescPingedCount(false);
if (pServer.LastDescPingedCount < 2)
{
// eserver 16.45+ supports a new OP_SERVER_DESC_RES answer, if the OP_SERVER_DESC_REQ contains a uint
// challenge, the server returns additional info with OP_SERVER_DESC_RES. To properly distinguish the
// old and new OP_SERVER_DESC_RES answer, the challenge has to be selected carefully. The first 2 bytes
// of the challenge (in network byte order) MUST NOT be a valid string-len-int16!
Packet packet1 =
MuleApplication.Instance.NetworkObjectManager.CreatePacket(OperationCodeEnum.OP_SERVER_DESC_REQ, 4);
uint uDescReqChallenge =
((uint)MpdUtilities.GetRandomUInt16() << 16) +
MuleConstants.INV_SERV_DESC_LEN; // 0xF0FF = an 'invalid' string length.
pServer.DescReqChallenge = uDescReqChallenge;
Array.Copy(BitConverter.GetBytes(uDescReqChallenge), packet1.Buffer, 4);
MuleApplication.Instance.Statistics.AddUpDataOverheadServer(packet1.Size);
MuleApplication.Instance.ServerConnect.SendUDPPacket(packet1, pServer, true);
}
else
{
pServer.SetLastDescPingedCount(true);
}
}
break;
}
case OperationCodeEnum.OP_SERVER_DESC_RES:
{
if (pServer == null)
{
return(true);
}
// old packet: <name_len 2><name name_len><desc_len 2 desc_en>
// new packet: <challenge 4><taglist>
//
// NOTE: To properly distinguish between the two packets which are both useing the same opcode...
// the first two bytes of <challenge> (in network byte order) have to be an invalid <name_len> at least.
SafeMemFile srvinfo = MpdObjectManager.CreateSafeMemFile(buffer, size);
if (size >= 8 && BitConverter.ToUInt16(buffer, 0) == MuleConstants.INV_SERV_DESC_LEN)
{
if (pServer.DescReqChallenge != 0 && BitConverter.ToUInt32(buffer, 0) == pServer.DescReqChallenge)
{
pServer.DescReqChallenge = 0;
srvinfo.ReadUInt32(); // skip challenge
uint uTags = srvinfo.ReadUInt32();
for (uint i = 0; i < uTags; i++)
{
Tag tag = MpdObjectManager.CreateTag(srvinfo, true /*pServer.GetUnicodeSupport()*/);
if (tag.NameID == MuleConstants.ST_SERVERNAME && tag.IsStr)
{
pServer.ServerName = tag.Str;
}
else if (tag.NameID == MuleConstants.ST_DESCRIPTION && tag.IsStr)
{
pServer.Description = tag.Str;
}
else if (tag.NameID == MuleConstants.ST_DYNIP && tag.IsStr)
{
// Verify that we really received a DN.
IPAddress address;
if (!IPAddress.TryParse(tag.Str, out address) ||
address == IPAddress.None)
{
string strOldDynIP = pServer.DynIP;
pServer.DynIP = tag.Str;
// If a dynIP-server changed its address or, if this is the
// first time we get the dynIP-address for a server which we
// already have as non-dynIP in our list, we need to remove
// an already available server with the same 'dynIP:port'.
if (string.Compare(strOldDynIP, pServer.DynIP, true) != 0)
{
MuleApplication.Instance.ServerList.RemoveDuplicatesByAddress(pServer);
}
}
}
else if (tag.NameID == MuleConstants.ST_VERSION && tag.IsStr)
{
pServer.Version = tag.Str;
}
else if (tag.NameID == MuleConstants.ST_VERSION && tag.IsInt)
{
pServer.Version =
string.Format("{0}.{1}", tag.Int >> 16, tag.Int & 0xFFFF);
}
}
}
else
{
// A server sent us a new server description packet (including a challenge) although we did not
// ask for it. This may happen, if there are multiple servers running on the same machine with
// multiple IPs. If such a server is asked for a description, the server will answer 2 times,
// but with the same IP.
}
}
else
{
string strName = srvinfo.ReadString(true /*pServer.GetUnicodeSupport()*/);
string strDesc = srvinfo.ReadString(true /*pServer.GetUnicodeSupport()*/);
pServer.Description = strDesc;
pServer.ServerName = strName;
}
break;
}
default:
return(false);
}
return(true);
}
catch (Exception error)
{
ProcessPacketError((uint)size, (uint)opcode, nIP, nUDPPort, error);
if (opcode == (byte)OperationCodeEnum.OP_GLOBSEARCHRES ||
opcode == (byte)OperationCodeEnum.OP_GLOBFOUNDSOURCES)
{
return(true);
}
}
return(false);
}
public virtual int EncryptSendClient(ref byte[] ppbyBuf, int nBufLen, byte[] pachClientHashOrKadID, bool bKad, uint nReceiverVerifyKey, uint nSenderVerifyKey)
{
Debug.Assert(MuleApplication.Instance.PublicIP != 0 || bKad);
Debug.Assert(MuleApplication.Instance.Preference.IsClientCryptLayerSupported);
Debug.Assert(pachClientHashOrKadID != null || nReceiverVerifyKey != 0);
Debug.Assert((nReceiverVerifyKey == 0 && nSenderVerifyKey == 0) || bKad);
byte byPadLen = 0; // padding disabled for UDP currently
int nCryptHeaderLen = byPadLen + CRYPT_HEADER_WITHOUTPADDING + (bKad ? 8 : 0);
int nCryptedLen = nBufLen + nCryptHeaderLen;
byte[] pachCryptedBuffer = new byte[nCryptedLen];
bool bKadRecKeyUsed = false;
ushort nRandomKeyPart = MpdUtilities.GetRandomUInt16();
MD5 md5 = MD5.Create();
byte[] rawHash = null;
if (bKad)
{
if ((pachClientHashOrKadID == null ||
MpdUtilities.IsNullMd4(pachClientHashOrKadID)) &&
nReceiverVerifyKey != 0)
{
bKadRecKeyUsed = true;
byte[] achKeyData = new byte[6];
Array.Copy(BitConverter.GetBytes(nReceiverVerifyKey), achKeyData, 4);
Array.Copy(BitConverter.GetBytes(nRandomKeyPart), 0,
achKeyData, 4, 2);
rawHash = md5.ComputeHash(achKeyData);
//DEBUG_ONLY( DebugLog(_T("Creating obfuscated Kad packet encrypted by ReceiverKey (%u)"), nReceiverVerifyKey) );
}
else if (pachClientHashOrKadID != null && !MpdUtilities.IsNullMd4(pachClientHashOrKadID))
{
byte[] achKeyData = new byte[18];
MpdUtilities.Md4Cpy(achKeyData, pachClientHashOrKadID);
Array.Copy(BitConverter.GetBytes(nRandomKeyPart), 0,
achKeyData, 16, 2);
rawHash = md5.ComputeHash(achKeyData);
//DEBUG_ONLY( DebugLog(_T("Creating obfuscated Kad packet encrypted by Hash/NodeID %s"), md4str(pachClientHashOrKadID)) );
}
else
{
ppbyBuf = null;
Debug.Assert(false);
return(nBufLen);
}
}
else
{
byte[] achKeyData = new byte[23];
MpdUtilities.Md4Cpy(achKeyData, pachClientHashOrKadID);
uint dwIP = (uint)MuleApplication.Instance.PublicIP;
Array.Copy(BitConverter.GetBytes(dwIP), 0, achKeyData, 16, 4);
Array.Copy(BitConverter.GetBytes(nRandomKeyPart), 0, achKeyData, 21, 2);
achKeyData[20] = MAGICVALUE_UDP;
rawHash = md5.ComputeHash(achKeyData);
}
RC4Key keySendKey = null;
MuleUtilities.RC4CreateKey(rawHash, 16, ref keySendKey, true);
// create the semi random byte encryption header
byte bySemiRandomNotProtocolMarker = 0;
int i;
for (i = 0; i < 128; i++)
{
bySemiRandomNotProtocolMarker = MpdUtilities.GetRandomUInt8();
bySemiRandomNotProtocolMarker =
(byte)(bKad ? (bySemiRandomNotProtocolMarker & 0xFE) :
(bySemiRandomNotProtocolMarker | 0x01)); // set the ed2k/kad marker bit
if (bKad)
{
bySemiRandomNotProtocolMarker =
(byte)(bKadRecKeyUsed ? ((bySemiRandomNotProtocolMarker & 0xFE) | 0x02) :
(bySemiRandomNotProtocolMarker & 0xFC)); // set the ed2k/kad and nodeid/reckey markerbit
}
else
{
bySemiRandomNotProtocolMarker = (byte)(bySemiRandomNotProtocolMarker | 0x01); // set the ed2k/kad marker bit
}
bool bOk = false;
switch (bySemiRandomNotProtocolMarker)
{ // not allowed values
case MuleConstants.PROTOCOL_EMULEPROT:
case MuleConstants.PROTOCOL_KADEMLIAPACKEDPROT:
case MuleConstants.PROTOCOL_KADEMLIAHEADER:
case MuleConstants.PROTOCOL_UDPRESERVEDPROT1:
case MuleConstants.PROTOCOL_UDPRESERVEDPROT2:
case MuleConstants.PROTOCOL_PACKEDPROT:
break;
default:
bOk = true;
break;
}
if (bOk)
{
break;
}
}
if (i >= 128)
{
// either we have _really_ bad luck or the randomgenerator is a bit messed up
Debug.Assert(false);
bySemiRandomNotProtocolMarker = 0x01;
}
uint dwMagicValue = MAGICVALUE_UDP_SYNC_CLIENT;
pachCryptedBuffer[0] = bySemiRandomNotProtocolMarker;
Array.Copy(BitConverter.GetBytes(nRandomKeyPart), 0, pachCryptedBuffer, 1, 2);
MuleUtilities.RC4Crypt(BitConverter.GetBytes(dwMagicValue), 0, pachCryptedBuffer, 3, 4, keySendKey);
MuleUtilities.RC4Crypt(BitConverter.GetBytes(byPadLen), 0, pachCryptedBuffer, 7, 1, keySendKey);
Random rand = new Random();
for (int j = 0; j < byPadLen; j++)
{
byte byRand = (byte)rand.Next(255); // they actually dont really need to be random, but it doesn't hurts either
MuleUtilities.RC4Crypt(BitConverter.GetBytes(byRand), 0,
pachCryptedBuffer, CRYPT_HEADER_WITHOUTPADDING + j, 1, keySendKey);
}
if (bKad)
{
MuleUtilities.RC4Crypt(BitConverter.GetBytes(nReceiverVerifyKey), 0,
pachCryptedBuffer, CRYPT_HEADER_WITHOUTPADDING + byPadLen, 4, keySendKey);
MuleUtilities.RC4Crypt(BitConverter.GetBytes(nSenderVerifyKey), 0,
pachCryptedBuffer, CRYPT_HEADER_WITHOUTPADDING + byPadLen + 4, 4, keySendKey);
}
MuleUtilities.RC4Crypt(ppbyBuf, 0,
pachCryptedBuffer, nCryptHeaderLen, (uint)nBufLen, keySendKey);
ppbyBuf = pachCryptedBuffer;
MuleApplication.Instance.Statistics.AddUpDataOverheadCrypt((uint)(nCryptedLen - nBufLen));
return(nCryptedLen);
}
public void ServerStats()
{
// Update the server list even if we are connected to Kademlia only. The idea is for both networks to keep
// each other up to date.. Kad network can get you back into the ED2K network.. And the ED2K network can get
// you back into the Kad network..
if (MuleApplication.Instance.ServerConnect.IsConnected &&
MuleApplication.Instance.ServerConnect.IsUDPSocketAvailable &&
servers_.Count > 0)
{
ED2KServer ping_server = GetNextStatServer();
if (ping_server == null)
{
return;
}
uint tNow = MpdUtilities.Time();
ED2KServer test = ping_server;
while (ping_server.LastPingedTime != 0 &&
(tNow - ping_server.LastPingedTime) < MuleConstants.UDPSERVSTATREASKTIME)
{
ping_server = GetNextStatServer();
if (ping_server == test)
{
return;
}
}
// IP-filter: We do not need to IP-filter any servers here, even dynIP-servers are not
// needed to get filtered here. See also comments in 'CServerSocket::ConnectTo'.
if (ping_server.FailedCount >= MuleApplication.Instance.Preference.DeadServerRetries)
{
RemoveServer(ping_server);
return;
}
Random rand = new Random((int)tNow);
ping_server.RealLastPingedTime = tNow; // this is not used to calcualte the next ping, but only to ensure a minimum delay for premature pings
if (!ping_server.CryptPingReplyPending &&
(tNow - ping_server.LastPingedTime) >= MuleConstants.UDPSERVSTATREASKTIME &&
MuleApplication.Instance.PublicIP != 0 &&
MuleApplication.Instance.Preference.IsServerCryptLayerUDPEnabled)
{
// we try a obfsucation ping first and wait 20 seconds for an answer
// if it doesn'T get responsed, we don't count it as error but continue with a normal ping
ping_server.CryptPingReplyPending = true;
int nPacketLen = 4 + (byte)(rand.Next() % 16); // max padding 16 bytes
byte[] pRawPacket = new byte[nPacketLen];
int dwChallenge = (rand.Next() << 17) | (rand.Next() << 2) | (rand.Next() & 0x03);
if (dwChallenge == 0)
{
dwChallenge++;
}
Array.Copy(BitConverter.GetBytes(dwChallenge), pRawPacket, 4);
for (uint i = 4; i < nPacketLen; i++) // fillung up the remaining bytes with random data
{
pRawPacket[i] = (byte)rand.Next();
}
ping_server.Challenge = (uint)dwChallenge;
ping_server.LastPinged = MpdUtilities.GetTickCount();
ping_server.LastPingedTime =
((tNow - (uint)MuleConstants.UDPSERVSTATREASKTIME) + 20); // give it 20 seconds to respond
MuleApplication.Instance.Statistics.AddUpDataOverheadServer((uint)nPacketLen);
MuleApplication.Instance.ServerConnect.SendUDPPacket(null,
ping_server, true, (ushort)(ping_server.Port + 12), pRawPacket, (uint)nPacketLen);
}
else if (ping_server.CryptPingReplyPending ||
MuleApplication.Instance.PublicIP == 0 ||
!MuleApplication.Instance.Preference.IsServerCryptLayerUDPEnabled)
{
// our obfsucation ping request was not answered, so probably the server doesn'T supports obfuscation
// continue with a normal request
ping_server.CryptPingReplyPending = false;
Packet packet = MuleApplication.Instance.NetworkObjectManager.CreatePacket(OperationCodeEnum.OP_GLOBSERVSTATREQ, 4);
int uChallenge = 0x55AA0000 + MpdUtilities.GetRandomUInt16();
ping_server.Challenge = (uint)uChallenge;
Array.Copy(BitConverter.GetBytes(uChallenge), packet.Buffer, 4);
ping_server.LastPinged = MpdUtilities.GetTickCount();
ping_server.LastPingedTime = (uint)(tNow - (rand.Next() % MuleConstants.ONE_HOUR_SEC));
ping_server.AddFailedCount();
MuleApplication.Instance.Statistics.AddUpDataOverheadServer(packet.Size);
MuleApplication.Instance.ServerConnect.SendUDPPacket(packet, ping_server, true);
}
else
{
Debug.Assert(false);
}
}
}
