//
// PublisherIdentityPermission.cs: Publisher Identity Permission
//
// Author:
//	Sebastien Pouliot  <sebastien@ximian.com>
//
// (C) 2002, 2003 Motus Technologies Inc. (http://www.motus.com)
// Copyright (C) 2004-2005 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.Runtime.InteropServices;
using System.Security.Cryptography.X509Certificates;

using Mono.Security.Cryptography;

namespace System.Security.Permissions {

	[ComVisible (true)]
	[Serializable]
	public sealed class PublisherIdentityPermission : CodeAccessPermission, IBuiltInPermission {

		private const int version = 1;

		private X509Certificate x509;
	
		public PublisherIdentityPermission (PermissionState state) 
		{
			// false == do not allow Unrestricted for Identity Permissions
			CheckPermissionState (state, false);
		}
	
		public PublisherIdentityPermission (X509Certificate certificate) 
		{
			// reuse validation by the Certificate property
			Certificate = certificate;
		}
	
		public X509Certificate Certificate { 
			get { return x509; }
			set { 
				if (value == null)
					throw new ArgumentNullException ("X509Certificate");
				x509 = value; 
			}
		}
	
		public override IPermission Copy () 
		{
			PublisherIdentityPermission p = new PublisherIdentityPermission (PermissionState.None);
			if (x509 != null)
				p.Certificate = x509;
			return p;
		}

		public override void FromXml (SecurityElement esd) 
		{
			// General validation in CodeAccessPermission
			CheckSecurityElement (esd, "esd", version, version);
			// Note: we do not (yet) care about the return value 
			// as we only accept version 1 (min/max values)

			string cert = (esd.Attributes ["X509v3Certificate"] as string);
			if (cert != null) {
				byte[] rawcert = CryptoConvert.FromHex (cert);
				x509 = new X509Certificate (rawcert);
			}
		}
	
		public override IPermission Intersect (IPermission target) 
		{
			PublisherIdentityPermission pip = Cast (target);
			if (pip == null)
				return null;

			if ((x509 != null) && (pip.x509 != null)) {
				if (x509.GetRawCertDataString () == pip.x509.GetRawCertDataString ())
					return new PublisherIdentityPermission (pip.x509);
			}
			return null;
		}
	
		public override bool IsSubsetOf (IPermission target) 
		{
			PublisherIdentityPermission pip = Cast (target);
			if (pip == null)
				return false;

			if (x509 == null)
				return true;
			if (pip.x509 == null)
				return false;
			return (x509.GetRawCertDataString () == pip.x509.GetRawCertDataString ());
		}
	
		public override SecurityElement ToXml () 
		{
			SecurityElement se = Element (version);
			if (x509 != null)
				se.AddAttribute ("X509v3Certificate", x509.GetRawCertDataString ());
			return se;
		}
	
		public override IPermission Union (IPermission target) 
		{
			PublisherIdentityPermission pip = Cast (target);
			if (pip == null)
				return Copy ();

			if ((x509 != null) && (pip.x509 != null)) {
				if (x509.GetRawCertDataString () == pip.x509.GetRawCertDataString ())
					return new PublisherIdentityPermission (x509); // any cert would do
			}
			else if ((x509 == null) && (pip.x509 != null))
				return new PublisherIdentityPermission (pip.x509);
			else if ((x509 != null) && (pip.x509 == null))
				return new PublisherIdentityPermission (x509);
			return null;
		}

		// IBuiltInPermission
		int IBuiltInPermission.GetTokenIndex ()
		{
			return (int) BuiltInToken.PublisherIdentity;
		}

		// helpers

		private PublisherIdentityPermission Cast (IPermission target)
		{
			if (target == null)
				return null;

			PublisherIdentityPermission pip = (target as PublisherIdentityPermission);
			if (pip == null) {
				ThrowInvalidPermission (target, typeof (PublisherIdentityPermission));
			}

			return pip;
		}
	}
}
