//
// System.Web.Security.UrlAuthorizationModule
//
// Authors:
//	Gonzalo Paniagua Javier (gonzalo@ximian.com)
//
// (C) 2002,2003 Ximian, Inc (http://www.ximian.com)
// Copyright (c) 2005 Novell, Inc (http://www.novell.com)
//
// 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.Configuration;
using System.Web.Configuration;
using System.Security.Permissions;
using System.Security.Principal;

namespace System.Web.Security
{
	// CAS - no InheritanceDemand here as the class is sealed
	[AspNetHostingPermission (SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
	public sealed class UrlAuthorizationModule : IHttpModule
	{
		[SecurityPermission (SecurityAction.Demand, UnmanagedCode = true)]
		public UrlAuthorizationModule ()
		{
		}

		public void Dispose ()
		{
		}

		public void Init (HttpApplication app)
		{
			app.AuthorizeRequest += new EventHandler (OnAuthorizeRequest);
		}

		void OnAuthorizeRequest (object sender, EventArgs args)
		{
			HttpApplication app = (HttpApplication) sender;
			HttpContext context = app.Context;
			if (context == null || context.SkipAuthorization)
				return;

			HttpRequest req = context.Request;
			AuthorizationSection config = (AuthorizationSection) WebConfigurationManager.GetSection ("system.web/authorization", req.Path, context);
			if (!config.IsValidUser (context.User, req.HttpMethod)) {
				HttpException e = new HttpException (401, "Unauthorized");
				HttpResponse response = context.Response;
				
				response.StatusCode = 401;
				response.Write (e.GetHtmlErrorMessage ());
				app.CompleteRequest ();
			}
		}

		public static bool CheckUrlAccessForPrincipal (string virtualPath, IPrincipal user, string verb)
		{
			AuthorizationSection config = (AuthorizationSection) WebConfigurationManager.GetSection ("system.web/authorization", virtualPath);

			return config == null ? true : config.IsValidUser (user, verb);
		}

		internal static void ReportUrlAuthorizationFailure(HttpContext context, object webEventSource) {
			// Deny access
			context.Response.StatusCode = 401;
			context.Response.Write (new HttpException(401, "Unauthorized").GetHtmlErrorMessage ());

#if false // Sys.Web.Mng not implemented on mono.
			if (context.User != null && context.User.Identity.IsAuthenticated) {
				// We don't raise failure audit event for anonymous user
				WebBaseEvent.RaiseSystemEvent(webEventSource, WebEventCodes.AuditUrlAuthorizationFailure);
			}
#endif
			context.ApplicationInstance.CompleteRequest();
		}

	}
}