class/corlib/System.Security.Permissions/ZoneIdentityPermission.cs

   1 //
   2 // System.Security.Permissions.ZoneIdentityPermission
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //      Sebastien Pouliot  <sebastien@ximian.com>
   7 //
   8 // (C) 2002 Ximian, Inc (http://www.ximian.com)
   9 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System.Globalization;
  32 using System.Runtime.InteropServices;
  33
  34 namespace System.Security.Permissions {
  35
  36         [ComVisible (true)]
  37         [Serializable]
  38         public sealed class ZoneIdentityPermission : CodeAccessPermission, IBuiltInPermission {
  39
  40                 private const int version = 1;
  41
  42                 private SecurityZone zone;
  43
  44                 public ZoneIdentityPermission (PermissionState state)
  45                 {
  46                         // false == do not allow Unrestricted for Identity Permissions
  47                         CheckPermissionState (state, false);
  48                         // default values
  49                         zone = SecurityZone.NoZone;
  50                 }
  51
  52                 public ZoneIdentityPermission (SecurityZone zone)
  53                 {
  54                         // also needs the validations
  55                         SecurityZone = zone;
  56                 }
  57
  58                 public override IPermission Copy ()
  59                 {
  60                         return new ZoneIdentityPermission (zone);
  61                 }
  62
  63                 public override bool IsSubsetOf (IPermission target)
  64                 {
  65                         ZoneIdentityPermission zip = Cast (target);
  66                         if (zip == null)
  67                                 return (zone == SecurityZone.NoZone);
  68
  69                         return ((zone == SecurityZone.NoZone) || (zone == zip.zone));
  70                 }
  71
  72                 public override IPermission Union (IPermission target)
  73                 {
  74                         ZoneIdentityPermission zip = Cast (target);
  75                         if (zip == null)
  76                                 return (zone == SecurityZone.NoZone) ? null : Copy ();
  77
  78                         if (zone == zip.zone || zip.zone == SecurityZone.NoZone)
  79                                 return Copy ();
  80
  81                         if (zone == SecurityZone.NoZone)
  82                                 return zip.Copy ();
  83                         throw new ArgumentException (Locale.GetText (
  84                                 "Union impossible"));
  85                 }
  86
  87                 public override IPermission Intersect (IPermission target)
  88                 {
  89                         ZoneIdentityPermission zip = Cast (target);
  90                         if (zip == null || zone == SecurityZone.NoZone)
  91                                 return null;
  92
  93                         if (zone == zip.zone)
  94                                 return Copy ();
  95
  96                         return null;
  97                 }
  98
  99                 public override void FromXml (SecurityElement esd)
 100                 {
 101                         // General validation in CodeAccessPermission
 102                         CheckSecurityElement (esd, "esd", version, version);
 103                         // Note: we do not (yet) care about the return value
 104                         // as we only accept version 1 (min/max values)
 105
 106                         string zoneName = esd.Attribute ("Zone");
 107                         if (zoneName == null)
 108                                 zone = SecurityZone.NoZone;
 109                         else
 110                                 zone = (SecurityZone) Enum.Parse (typeof (SecurityZone), zoneName);
 111                 }
 112
 113                 public override SecurityElement ToXml ()
 114                 {
 115                         SecurityElement se = Element (version);
 116                         if (zone != SecurityZone.NoZone)
 117                                 se.AddAttribute ("Zone", zone.ToString ());
 118                         return se;
 119                 }
 120
 121                 public SecurityZone SecurityZone {
 122                         get { return zone; }
 123                         set {
 124                                 if (!Enum.IsDefined (typeof (SecurityZone), value)) {
 125                                         string msg = String.Format (Locale.GetText ("Invalid enum {0}"), value);
 126                                         throw new ArgumentException (msg, "SecurityZone");
 127                                 }
 128                                 zone = value;
 129                         }
 130                 }
 131
 132                 // IBuiltInPermission
 133                 int IBuiltInPermission.GetTokenIndex ()
 134                 {
 135                         return (int) BuiltInToken.ZoneIdentity;
 136                 }
 137
 138                 // helpers
 139
 140                 private ZoneIdentityPermission Cast (IPermission target)
 141                 {
 142                         if (target == null)
 143                                 return null;
 144
 145                         ZoneIdentityPermission zip = (target as ZoneIdentityPermission);
 146                         if (zip == null) {
 147                                 ThrowInvalidPermission (target, typeof (ZoneIdentityPermission));
 148                         }
 149
 150                         return zip;
 151                 }
 152         }
 153 }
 154