/// <summary>
/// Validate NL_AUTH_MESSAGE when the server receives token from client
/// MessageType is not set to 0x00000000.
/// contains at least one domain name and one computer name
/// </summary>
/// <param name="inToken">token from client</param>
/// <returns>True if validate pass; otherwise, false</returns>
/// <exception cref="ArgumentException">Thrown when length of inToken is not large enough.</exception>
private bool ValidateNlAuthMessage(byte[] inToken)
{
if (inToken.Length <= (sizeof(MessageType_Values) + sizeof(NL_AUTH_MESSAGE_Flags_Value)))
{
throw new ArgumentException("The token is invalid", "inToken");
}
NL_AUTH_MESSAGE nlAuthMessage = new NL_AUTH_MESSAGE();
// convert inToken to a NL_AUTH_MESSAGE structure
int offset = 0;
nlAuthMessage.MessageType = (MessageType_Values)BitConverter.ToInt32(inToken, offset);
offset += sizeof(MessageType_Values);
nlAuthMessage.Flags = (NL_AUTH_MESSAGE_Flags_Value)BitConverter.ToUInt32(inToken, offset);
offset += sizeof(NL_AUTH_MESSAGE_Flags_Value);
nlAuthMessage.Buffer = ArrayUtility.SubArray(inToken, offset, inToken.Length - offset);
// check message type
if (nlAuthMessage.MessageType != MessageType_Values.NegotiateRequest)
{
return(false);
}
// check domain name and computer name, must present both
string domainName = null;
string computerName = null;
List <string> nameList = new List <string>();
foreach (string name in Encoding.ASCII.GetString(nlAuthMessage.Buffer).Split(NULL))
{
if (!string.IsNullOrEmpty(name))
{
nameList.Add(name);
}
}
if (nameList.Count == 0)
{
return(false);
}
int index = 0;
if ((nlAuthMessage.Flags & NL_AUTH_MESSAGE_Flags_Value.NetbiosOemDomainName) != 0 &&
index < nameList.Count)
{
domainName = nameList[index++];
}
if ((nlAuthMessage.Flags & NL_AUTH_MESSAGE_Flags_Value.NetbiosOemComputerName) != 0 &&
index < nameList.Count)
{
computerName = nameList[index++];
}
if ((nlAuthMessage.Flags & NL_AUTH_MESSAGE_Flags_Value.DnsCompressedDomainName) != 0 &&
index < nameList.Count)
{
domainName =
Rfc1035Utility.FromCompressedUtf8String(Encoding.ASCII.GetBytes(nameList[index++]));
}
if ((nlAuthMessage.Flags & NL_AUTH_MESSAGE_Flags_Value.DnsCompressedHostName) != 0 &&
index < nameList.Count)
{
computerName =
Rfc1035Utility.FromCompressedUtf8String(Encoding.ASCII.GetBytes(nameList[index++]));
}
if ((nlAuthMessage.Flags & NL_AUTH_MESSAGE_Flags_Value.NetbiosCompressedComputerName) != 0 &&
index < nameList.Count)
{
computerName =
Rfc1035Utility.FromCompressedUtf8String(Encoding.ASCII.GetBytes(nameList[index++]));
}
if (domainName == null || computerName == null)
{
return(false);
}
return(true);
}
