.NET Remoting Customization Made Easy: Custom Sinks

//
// Written by Motti Shaked
//
// motti@wincode.net
//
// Version: 1.0.0.0
//
// DISCLAIMER:
//
// You may use this code as you please.
// You may modify and share it freely.
// You may NOT hold me liable for any damage
// caused to you, your company, your neighbors,
// or anyone else as a result of using this code,
// taking ideas from it, dreaming of it,
// or any other use you may find it suitable for.
// Whatever you do with this code is at 
// your own risk.
//
// Enjoy!
// 

using System;
using System.IO;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Channels;
using System.Runtime.Remoting.Messaging;
using System.Collections;

using CustomSinks;

namespace CredentialsSinks
{
	public class DemoCredentialsServerSink : BaseCustomSink
	{
		private Credentials [] credentialsList;

		public DemoCredentialsServerSink(SinkCreationData data)
		{
			SinkProviderData credentialsListConfig = null;

			// find the credentialsList element
			foreach (SinkProviderData d in data.ConfigurationData.Children)
			{
				if (d.Name == "credentialsList")
				{
					credentialsListConfig = d;
					break;
				}
			}

			// if the credentialsList element is not found - nothing to do here
			if (credentialsListConfig == null)
			{
				return;
			
			}

			ArrayList tempCeredentialsList = new ArrayList();

			// iterate through the credentials elements
			// and them to the hashtable
			Credentials credentials;
			foreach (SinkProviderData credConfig in credentialsListConfig.Children)
			{
				if (credConfig.Name != "credentials")
				{
					continue;
				}

				credentials = new Credentials(
					(string)credConfig.Properties["username"], 
					(string)credConfig.Properties["password"]);

				tempCeredentialsList.Add(credentials);
			}

			// switch to array and sort it to enable binary search
			this.credentialsList = (Credentials [])tempCeredentialsList.ToArray(typeof(Credentials));
			Array.Sort(this.credentialsList);
		}

		// only ProcessRequest
		// no need for ProcessResponse
		protected override void ProcessRequest(IMessage message, ITransportHeaders headers, ref Stream stream, ref object state)
		{
			Credentials credentials = message.Properties["DemoCredentials"] as Credentials;
			if (credentials != null && Array.BinarySearch(this.credentialsList, credentials) >= 0)
			{
				// okay
				Console.WriteLine(
					"DemoCredentialsServerSink: retrieved valid credential information: username: {0}, password {1}.",
					credentials.Username, credentials.Password);
				return;
			}

			// not good!
			Console.WriteLine(
				"DemoCredentialsServerSink: retrieved bad credentials or credentials are missing. Throwing an exception.");
			throw new RemotingException("Invalid credentials.");
		}
	}
}