/// <summary>
/// Server X.224 Connection Confirm PDU
/// </summary>
private static int receiveConnectNegotiation()
{
RdpPacket packet = ISO.Receive();
packet.Position += 7L;
if (packet.Position >= packet.Length)
{
return(0);
}
switch (packet.ReadByte())
{
// TYPE_RDP_NEG_RSP
case 0x02:
Options.serverNegotiateFlags = (NegotiationFlags)packet.ReadByte();
packet.ReadLittleEndian16();
return(packet.ReadLittleEndian32());
// TYPE_RDP_NEG_FAILURE
case 0x03:
packet.ReadByte();
packet.ReadLittleEndian16();
switch ((NegotiationFailureCodes)packet.ReadLittleEndian32())
{
case NegotiationFailureCodes.SSL_REQUIRED_BY_SERVER:
throw new RDFatalException("The server requires that the client support Enhanced RDP Security with TLS 1.0");
case NegotiationFailureCodes.SSL_NOT_ALLOWED_BY_SERVER:
return(0x10000000);
case NegotiationFailureCodes.SSL_CERT_NOT_ON_SERVER:
throw new RDFatalException("The server does not possess a valid authentication certificate and cannot initialize the External Security Protocol Provider");
case NegotiationFailureCodes.INCONSISTENT_FLAGS:
throw new RDFatalException("The list of requested security protocols is not consistent with the current security protocol in effect.");
case NegotiationFailureCodes.HYBRID_REQUIRED_BY_SERVER:
throw new RDFatalException("The server requires that the client support Enhanced RDP Security with CredSSP");
case NegotiationFailureCodes.SSL_WITH_USER_AUTH_REQUIRED_BY_SERVER:
throw new RDFatalException("The server requires that the client support Enhanced RDP Security and certificate-based client authentication");
}
throw new RDFatalException("Unknown Negotiation failure!");
}
throw new RDFatalException("Negotiation failed, requested security level not supported by server.");
}
public void Parse(RdpPacket packet)
{
NTLM.AV_ID av_id;
byte[] buffer = null;
do
{
av_id = (NTLM.AV_ID)packet.ReadLittleEndian16();
int count = packet.ReadLittleEndian16();
if (count > 0)
{
if (av_id != NTLM.AV_ID.MsvAvFlags)
{
buffer = new byte[count];
packet.Read(buffer, 0, count);
}
else
{
this.Flags = packet.ReadLittleEndian32();
}
}
switch (av_id)
{
case NTLM.AV_ID.MsvAvNbComputerName:
this.NbComputerName.length = count;
this.NbComputerName.value = buffer;
this.sNbComputerName = Encoding.Unicode.GetString(this.NbComputerName.value, 0, this.NbComputerName.value.Length);
break;
case NTLM.AV_ID.MsvAvNbDomainName:
this.NbDomainName.length = count;
this.NbDomainName.value = buffer;
this.sNbDomainName = Encoding.Unicode.GetString(this.NbDomainName.value, 0, this.NbDomainName.value.Length);
break;
case NTLM.AV_ID.MsvAvDnsComputerName:
this.DnsComputerName.length = count;
this.DnsComputerName.value = buffer;
this.sDnsComputerName = Encoding.Unicode.GetString(this.DnsComputerName.value, 0, this.DnsComputerName.value.Length);
break;
case NTLM.AV_ID.MsvAvDnsDomainName:
this.DnsDomainName.length = count;
this.DnsDomainName.value = buffer;
this.sDnsDomainName = Encoding.Unicode.GetString(this.DnsDomainName.value, 0, this.DnsDomainName.value.Length);
break;
case NTLM.AV_ID.MsvAvDnsTreeName:
this.DnsTreeName.length = count;
this.DnsTreeName.value = buffer;
break;
case NTLM.AV_ID.MsvAvTimestamp:
this.Timestamp.length = count;
this.Timestamp.value = buffer;
break;
case NTLM.AV_ID.MsvAvRestrictions:
this.Restrictions.length = count;
this.Restrictions.value = buffer;
break;
case NTLM.AV_ID.MsvAvTargetName:
this.TargetName.length = count;
this.TargetName.value = buffer;
break;
case NTLM.AV_ID.MsvChannelBindings:
this.ChannelBindings.length = count;
this.ChannelBindings.value = buffer;
break;
}
}while (av_id != NTLM.AV_ID.MsvAvEOL);
}
public byte[] ProcessChallenge(byte[] Challenge)
{
byte[] bytes;
RdpPacket packet = new RdpPacket();
this.m_ChallengeMsg = Challenge;
packet.Write(Challenge, 0, Challenge.Length);
packet.Position = 0L;
long position = packet.Position;
if (packet.ReadString(8) != "NTLMSSP\0")
{
throw new Exception("Invalid negotiation token!");
}
if (packet.ReadLittleEndian32() != 2)
{
throw new Exception("Expected challenge!");
}
int count = packet.ReadLittleEndian16();
packet.ReadLittleEndian16();
int num4 = packet.ReadLittleEndian32();
uint flags = (uint)packet.ReadLittleEndian32();
DumpFlags(flags);
byte[] buffer = new byte[8];
packet.Read(buffer, 0, 8);
DumpHex(buffer, buffer.Length, "Server Challenge");
byte[] buffer2 = new byte[8];
packet.Read(buffer2, 0, 8);
int num5 = packet.ReadLittleEndian16();
packet.ReadLittleEndian16();
int num6 = packet.ReadLittleEndian32();
if ((flags & 0x2000000) != 0)
{
byte[] buffer3 = new byte[8];
packet.Read(buffer3, 0, 8);
}
if ((flags & 0x20000000) == 0)
{
throw new Exception("Strong Encryption not supported by server");
}
byte[] buffer4 = null;
if (count > 0)
{
buffer4 = new byte[count];
packet.Position = position + num4;
packet.Read(buffer4, 0, count);
Encoding.Unicode.GetString(buffer4, 0, buffer4.Length);
}
AV_PAIRS av_pairs = new AV_PAIRS();
byte[] buffer5 = null;
if (num5 <= 0)
{
throw new Exception("No TargetInfo!");
}
packet.Position = position + num6;
buffer5 = new byte[num5];
packet.Read(buffer5, 0, num5);
packet = new RdpPacket();
packet.Write(buffer5, 0, buffer5.Length);
packet.Position = 0L;
av_pairs.Parse(packet);
buffer5 = av_pairs.Serialise();
byte[] data = nTOWFv2(this.m_sDomain, this.m_sUsername, this.m_sPassword);
if (Network.Logger != null)
{
if (Network.Logger.Reading)
{
data = this.m_Socket.GetBlob(PacketLogger.PacketType.NTLM_ResponseKeyNT);
}
else
{
this.m_Socket.AddBlob(PacketLogger.PacketType.NTLM_ResponseKeyNT, data);
}
}
byte[] blob = new byte[8];
RNGCryptoServiceProvider provider = new RNGCryptoServiceProvider();
provider.GetBytes(blob);
if (Network.Logger != null)
{
if (Network.Logger.Reading)
{
blob = this.m_Socket.GetBlob(PacketLogger.PacketType.NTLM_ClientChallenge);
}
else
{
this.m_Socket.AddBlob(PacketLogger.PacketType.NTLM_ClientChallenge, blob);
}
}
DumpHex(blob, blob.Length, "Client Challenge");
byte[] buffer8 = getLMv2Response(data, buffer, blob);
DumpHex(buffer8, buffer8.Length, "LM Response");
if (this.m_bNTLMv2)
{
Array.Clear(buffer8, 0, buffer8.Length);
}
bool bGenerateMIC = false;
if ((av_pairs.Timestamp.length <= 0) || !this.m_bNTLMv2)
{
bytes = BitConverter.GetBytes(DateTime.UtcNow.ToFileTimeUtc());
}
else
{
bytes = av_pairs.Timestamp.value;
bGenerateMIC = true;
av_pairs.ProcessForNTLMv2();
buffer5 = av_pairs.Serialise();
}
DumpHex(buffer5, buffer5.Length, "targetinfo");
byte[] keyExchangeKey = null;
byte[] buffer11 = getNTLMv2Response(data, buffer, blob, bytes, buffer5, out keyExchangeKey);
DumpHex(buffer11, buffer11.Length, "NTLMv2 Response");
if (Network.Logger != null)
{
if (Network.Logger.Reading)
{
keyExchangeKey = this.m_Socket.GetBlob(PacketLogger.PacketType.NTLM_KeyExchangeKey);
}
else
{
this.m_Socket.AddBlob(PacketLogger.PacketType.NTLM_KeyExchangeKey, keyExchangeKey);
}
}
byte[] encryptedRandomSessionKey = null;
byte[] buffer13 = null;
buffer13 = new byte[0x10];
provider.GetBytes(buffer13);
if (Network.Logger != null)
{
if (Network.Logger.Reading)
{
buffer13 = this.m_Socket.GetBlob(PacketLogger.PacketType.NTLM_ExportedSessionKey);
}
else
{
this.m_Socket.AddBlob(PacketLogger.PacketType.NTLM_ExportedSessionKey, buffer13);
}
}
encryptedRandomSessionKey = new byte[0x10];
RC4 rc = new RC4();
rc.engineInitEncrypt(keyExchangeKey);
encryptedRandomSessionKey = rc.crypt(buffer13);
if ((flags & 0x40000000) == 0)
{
encryptedRandomSessionKey = new byte[0];
buffer13 = keyExchangeKey;
}
this.InitSignKeys(buffer13);
return(this.Authenticate(buffer8, buffer11, this.m_sDomain, this.m_sUsername, this.m_sWorkstation, encryptedRandomSessionKey, buffer13, bGenerateMIC));
}
