mcs/class/corlib/System.Security.Permissions/DataProtectionPermission.cs

   1 //
   2 // System.Security.Permissions.DataProtectionPermission class
   3 //
   4 // Author:
   5 //      Sebastien Pouliot  <sebastien@ximian.com>
   6 //
   7 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 #if NET_2_0
  30
  31 using System.Globalization;
  32
  33 namespace System.Security.Permissions {
  34
  35         [Serializable]
  36         public sealed class DataProtectionPermission : CodeAccessPermission, IUnrestrictedPermission, IBuiltInPermission {
  37
  38                 private const int version = 1;
  39
  40                 private DataProtectionPermissionFlags _flags;
  41
  42
  43                 public DataProtectionPermission (PermissionState state)
  44                 {
  45                         if (CheckPermissionState (state, true) == PermissionState.Unrestricted)
  46                                 _flags = DataProtectionPermissionFlags.AllFlags;
  47                         else
  48                                 _flags = DataProtectionPermissionFlags.NoFlags;
  49                 }
  50
  51                 public DataProtectionPermission (DataProtectionPermissionFlags flags)
  52                 {
  53                         // reuse validation by the Flags property
  54                         Flags = flags;
  55                 }
  56
  57
  58                 public DataProtectionPermissionFlags Flags {
  59                         get { return _flags; }
  60                         set {
  61                                 if (!Enum.IsDefined (typeof (DataProtectionPermissionFlags), value)) {
  62                                         string msg = String.Format (Locale.GetText ("Invalid enum {0}"), value);
  63                                         throw new ArgumentException (msg, "DataProtectionPermissionFlags");
  64                                 }
  65                                 _flags = value;
  66                         }
  67                 }
  68
  69                 public bool IsUnrestricted ()
  70                 {
  71                         return (_flags == DataProtectionPermissionFlags.AllFlags);
  72                 }
  73
  74                 public override IPermission Copy ()
  75                 {
  76                         return new DataProtectionPermission (_flags);
  77                 }
  78
  79                 public override IPermission Intersect (IPermission target)
  80                 {
  81                         DataProtectionPermission dp = Cast (target);
  82                         if (dp == null)
  83                                 return null;
  84
  85                         if (this.IsUnrestricted () && dp.IsUnrestricted ())
  86                                 return new DataProtectionPermission (PermissionState.Unrestricted);
  87                         if (this.IsUnrestricted ())
  88                                 return dp.Copy ();
  89                         if (dp.IsUnrestricted ())
  90                                 return this.Copy ();
  91                         return new DataProtectionPermission (_flags & dp._flags);
  92                 }
  93
  94                 public override IPermission Union (IPermission target)
  95                 {
  96                         DataProtectionPermission dp = Cast (target);
  97                         if (dp == null)
  98                                 return this.Copy ();
  99
 100                         if (this.IsUnrestricted () || dp.IsUnrestricted ())
 101                                 return new SecurityPermission (PermissionState.Unrestricted);
 102
 103                         return new DataProtectionPermission (_flags | dp._flags);
 104                 }
 105
 106                 public override bool IsSubsetOf (IPermission target)
 107                 {
 108                         DataProtectionPermission dp = Cast (target);
 109                         if (dp == null)
 110                                 return (_flags == DataProtectionPermissionFlags.NoFlags);
 111
 112                         if (dp.IsUnrestricted ())
 113                                 return true;
 114                         if (this.IsUnrestricted ())
 115                                 return false;
 116
 117                         return ((_flags & ~dp._flags) == 0);
 118                 }
 119
 120                 public override void FromXml (SecurityElement e)
 121                 {
 122                         // General validation in CodeAccessPermission
 123                         CheckSecurityElement (e, "e", version, version);
 124                         // Note: we do not (yet) care about the return value
 125                         // as we only accept version 1 (min/max values)
 126
 127                         _flags = (DataProtectionPermissionFlags) Enum.Parse (
 128                                 typeof (DataProtectionPermissionFlags), e.Attribute ("Flags"));
 129                 }
 130
 131                 public override SecurityElement ToXml ()
 132                 {
 133                         SecurityElement e = Element (version);
 134                         e.AddAttribute ("Flags", _flags.ToString ());
 135                         return e;
 136                 }
 137
 138                 // IBuiltInPermission
 139                 int IBuiltInPermission.GetTokenIndex ()
 140                 {
 141                         return (int) BuiltInToken.DataProtection;
 142                 }
 143
 144                 // helpers
 145
 146                 private DataProtectionPermission Cast (IPermission target)
 147                 {
 148                         if (target == null)
 149                                 return null;
 150
 151                         DataProtectionPermission dp = (target as DataProtectionPermission);
 152                         if (dp == null) {
 153                                 ThrowInvalidPermission (target, typeof (DataProtectionPermission));
 154                         }
 155
 156                         return dp;
 157                 }
 158         }
 159 }
 160
 161 #endif