//
// Mono.Security.Protocol.Ntlm.Type1Message - Negotiation
//
// Author:
//	Sebastien Pouliot (spouliot@motus.com)
//
// Copyright (C) 2003 Motus Technologies Inc. (http://www.motus.com)
//
// References
// a.	NTLM Authentication Scheme for HTTP, Ronald Tschalär
//	http://www.innovation.ch/java/ntlm.html
// b.	The NTLM Authentication Protocol, Copyright © 2003 Eric Glass
//	http://davenport.sourceforge.net/ntlm.html
//

using System;
using System.Text;

namespace Mono.Security.Protocol.Ntlm {

	public class Type1Message : MessageBase {

		//static private byte[] header = { 0x4e, 0x54, 0x4c, 0x4d, 0x53, 0x53, 0x50, 0x00, 0x01, 0x00, 0x00, 0x00, 0x03, 0xb2, 0x00, 0x00 };

		private string _host;
		private string _domain;

		public Type1Message () : base (1)
		{
			// default values
			_domain = Environment.UserDomainName;
			_host = Environment.MachineName;
			Flags = (NtlmFlags) 0xb203;
		}

		public Type1Message (byte[] message) : base (1)
		{
			Decode (message);
		}

		// properties

		public string Domain {
			get { return _domain; }
			set { _domain = value; }
		}

		public string Host {
			get { return _host; }
			set { _host = value; }
		}

		// methods

		protected override void Decode (byte[] message) 
		{
			base.Decode (message);

			Flags = (NtlmFlags) BitConverter.ToUInt32 (message, 12);

			int dom_len = BitConverter.ToUInt16 (message, 16);
			int dom_off = BitConverter.ToUInt16 (message, 20);
			_domain = Encoding.ASCII.GetString (message, dom_off, dom_len);

			int host_len = BitConverter.ToUInt16 (message, 24);
			_host = Encoding.ASCII.GetString (message, 32, host_len);
		}

		public override byte[] GetBytes () 
		{
			short dom_len = (short) _domain.Length;
			short host_len = (short) _host.Length;

			byte[] data = PrepareMessage (32 + dom_len + host_len);

			data [12] = (byte) Flags;
			data [13] = (byte)((uint)Flags >> 8);
			data [14] = (byte)((uint)Flags >> 16);
			data [15] = (byte)((uint)Flags >> 24);

			short dom_off = (short)(32 + host_len);

			data [16] = (byte) dom_len;
			data [17] = (byte)(dom_len >> 8);
			data [18] = data [16];
			data [19] = data [17];
			data [20] = (byte) dom_off;
			data [21] = (byte)(dom_off >> 8);

			data [24] = (byte) host_len;
			data [25] = (byte)(host_len >> 8);
			data [26] = data [24];
			data [27] = data [25];
			data [28] = 0x20;
			data [29] = 0x00;

			byte[] host = Encoding.ASCII.GetBytes (_host.ToUpper ());
			Buffer.BlockCopy (host, 0, data, 32, host.Length);

			byte[] domain = Encoding.ASCII.GetBytes (_domain.ToUpper ());
			Buffer.BlockCopy (domain, 0, data, dom_off, domain.Length);

			return data;
		}
	}
}