AuthenticationManager.cs

//
// System.Net.AuthenticationManager.cs
//
// Author:
// 	Miguel de Icaza (miguel@ximian.com)
//	Gonzalo Paniagua Javier (gonzalo@ximian.com)
//
// (C) 2002,2003 Ximian, Inc. (http://www.ximian.com)
//

// Copyright (c) 2018 Nivloc Enterprises Ltd

//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using System.Collections;
using System.Collections.Specialized;
#if SSHARP
#else
using System.Configuration;
using System.Net.Configuration;
#endif

#if SSHARP
namespace SSMono.Net
#else
namespace System.Net
#endif
	{
	public class AuthenticationManager
		{
		private static ArrayList modules;
		private static object locker = new object ();

		private AuthenticationManager ()
			{
			}

		private static void EnsureModules ()
			{
			lock (locker)
				{
				if (modules != null)
					return;

				modules = new ArrayList ();
#if NET_2_1 || SSHARP
#if !SSHARP
				modules.Add (new NtlmClient ());
#endif
				modules.Add (new DigestClient ());
				modules.Add (new BasicClient ());
#elif CONFIGURATION_DEP
				object cfg = ConfigurationManager.GetSection ("system.net/authenticationModules");
				AuthenticationModulesSection s = cfg as AuthenticationModulesSection;
				if (s != null) {
					foreach (AuthenticationModuleElement element in s.AuthenticationModules) {
						IAuthenticationModule module = null;
						try {
							Type type = Type.GetType (element.Type, true);
							module = (IAuthenticationModule) Activator.CreateInstance (type);
						} catch {}
						modules.Add (module);
					}
				}
#else
				ConfigurationSettings.GetConfig ("system.net/authenticationModules");
#endif
				}
			}

		private static ICredentialPolicy credential_policy = null;

		public static ICredentialPolicy CredentialPolicy
			{
			get { return (credential_policy); }
			set { credential_policy = value; }
			}

		private static Exception GetMustImplement ()
			{
			return new NotImplementedException ();
			}

		[MonoTODO]
		public static StringDictionary CustomTargetNameDictionary
			{
			get { throw GetMustImplement (); }
			}

		public static IEnumerator RegisteredModules
			{
			get
				{
				EnsureModules ();
				return modules.GetEnumerator ();
				}
			}

		internal static void Clear ()
			{
			EnsureModules ();
			lock (modules)
				modules.Clear ();
			}

		public static Authorization Authenticate (string challenge, WebRequest request, ICredentials credentials)
			{
			if (request == null)
				throw new ArgumentNullException ("request");

			if (credentials == null)
				throw new ArgumentNullException ("credentials");

			if (challenge == null)
				throw new ArgumentNullException ("challenge");

			return DoAuthenticate (challenge, request, credentials);
			}

		private static Authorization DoAuthenticate (string challenge, WebRequest request, ICredentials credentials)
			{
			EnsureModules ();
			lock (modules)
				{
				foreach (IAuthenticationModule mod in modules)
					{
					Authorization auth = mod.Authenticate (challenge, request, credentials);
					if (auth == null)
						continue;

					auth.Module = mod;
					return auth;
					}
				}

			return null;
			}

		public static Authorization PreAuthenticate (WebRequest request, ICredentials credentials)
			{
			if (request == null)
				throw new ArgumentNullException ("request");

			if (credentials == null)
				return null;

			EnsureModules ();
			lock (modules)
				{
				foreach (IAuthenticationModule mod in modules)
					{
					Authorization auth = mod.PreAuthenticate (request, credentials);
					if (auth == null)
						continue;

					auth.Module = mod;
					return auth;
					}
				}

			return null;
			}

		public static void Register (IAuthenticationModule authenticationModule)
			{
			if (authenticationModule == null)
				throw new ArgumentNullException ("authenticationModule");

			DoUnregister (authenticationModule.AuthenticationType, false);
			lock (modules)
				modules.Add (authenticationModule);
			}

		public static void Unregister (IAuthenticationModule authenticationModule)
			{
			if (authenticationModule == null)
				throw new ArgumentNullException ("authenticationModule");

			DoUnregister (authenticationModule.AuthenticationType, true);
			}

		public static void Unregister (string authenticationScheme)
			{
			if (authenticationScheme == null)
				throw new ArgumentNullException ("authenticationScheme");

			DoUnregister (authenticationScheme, true);
			}

		private static void DoUnregister (string authenticationScheme, bool throwEx)
			{
			EnsureModules ();
			lock (modules)
				{
				IAuthenticationModule module = null;
				foreach (IAuthenticationModule mod in modules)
					{
					string modtype = mod.AuthenticationType;
					if (String.Compare (modtype, authenticationScheme, true) == 0)
						{
						module = mod;
						break;
						}
					}

				if (module == null)
					{
					if (throwEx)
						throw new InvalidOperationException ("Scheme not registered.");
					}
				else
					modules.Remove (module);
				}
			}
		}
	}