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

   1 //
   2 // System.Security.Permissions.SecurityPermission.cs
   3 //
   4 // Authors:
   5 //      Dan Lewis (dihlewis@yahoo.co.uk)
   6 //      Sebastien Pouliot (spouliot@motus.com)
   7 //
   8 // (C) 2002
   9 // Portions (C) 2003 Motus Technologies Inc. (http://www.motus.com)
  10 //
  11
  12 //
  13 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  14 //
  15 // Permission is hereby granted, free of charge, to any person obtaining
  16 // a copy of this software and associated documentation files (the
  17 // "Software"), to deal in the Software without restriction, including
  18 // without limitation the rights to use, copy, modify, merge, publish,
  19 // distribute, sublicense, and/or sell copies of the Software, and to
  20 // permit persons to whom the Software is furnished to do so, subject to
  21 // the following conditions:
  22 //
  23 // The above copyright notice and this permission notice shall be
  24 // included in all copies or substantial portions of the Software.
  25 //
  26 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  27 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  28 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  29 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  30 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  31 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  32 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  33 //
  34
  35 using System;
  36 using System.Globalization;
  37
  38 namespace System.Security.Permissions {
  39
  40         [Serializable]
  41         public sealed class SecurityPermission :
  42                 CodeAccessPermission, IUnrestrictedPermission, IBuiltInPermission {
  43
  44                 private SecurityPermissionFlag flags;
  45
  46                 // constructors
  47
  48                 public SecurityPermission (PermissionState state)
  49                 {
  50                         if (state == PermissionState.Unrestricted)
  51                                 flags = SecurityPermissionFlag.AllFlags;
  52                         else
  53                                 flags = SecurityPermissionFlag.NoFlags;
  54                 }
  55
  56                 public SecurityPermission (SecurityPermissionFlag flags)
  57                 {
  58                         this.flags = flags;
  59                 }
  60
  61                 public SecurityPermissionFlag Flags {
  62                         get { return flags; }
  63                         set { flags = value; }
  64                 }
  65
  66                 public bool IsUnrestricted ()
  67                 {
  68                         return (flags == SecurityPermissionFlag.AllFlags);
  69                 }
  70
  71                 public override IPermission Copy ()
  72                 {
  73                         return new SecurityPermission (flags);
  74                 }
  75
  76                 internal SecurityPermission Cast (IPermission target)
  77                 {
  78                         SecurityPermission perm = (target as SecurityPermission);
  79                         if (perm == null)
  80                                 throw new ArgumentException ("wrong type for target");
  81                         return perm;
  82                 }
  83
  84                 public override IPermission Intersect (IPermission target)
  85                 {
  86                         if (target == null)
  87                                 return null;
  88
  89                         SecurityPermission perm = Cast (target);
  90                         if (this.IsUnrestricted () && perm.IsUnrestricted ())
  91                                 return new SecurityPermission (PermissionState.Unrestricted);
  92                         if (this.IsUnrestricted ())
  93                                 return perm.Copy ();
  94                         if (perm.IsUnrestricted ())
  95                                 return this.Copy ();
  96                         return new SecurityPermission (flags & perm.flags);
  97                 }
  98
  99                 public override IPermission Union (IPermission target)
 100                 {
 101                         if (target == null)
 102                                 return this.Copy ();
 103
 104                         SecurityPermission perm = Cast (target);
 105                         if (this.IsUnrestricted () || perm.IsUnrestricted ())
 106                                 return new SecurityPermission (PermissionState.Unrestricted);
 107
 108                         return new SecurityPermission (flags | perm.flags);
 109                 }
 110
 111                 public override bool IsSubsetOf (IPermission target)
 112                 {
 113                         if (target == null)
 114                                 return (flags == SecurityPermissionFlag.NoFlags);
 115
 116                         SecurityPermission perm = Cast (target);
 117                         if (perm.IsUnrestricted ())
 118                                 return true;
 119                         if (this.IsUnrestricted ())
 120                                 return false;
 121
 122                         return ((flags & ~perm.flags) == 0);
 123                 }
 124
 125                 public override void FromXml (SecurityElement e)
 126                 {
 127                         if (e == null)
 128                                 throw new ArgumentNullException (
 129                                         Locale.GetText ("The argument is null."));
 130
 131                         if (e.Attribute ("class") != GetType ().AssemblyQualifiedName)
 132                                 throw new ArgumentException (
 133                                         Locale.GetText ("The argument is not valid"));
 134
 135                         if (e.Attribute ("version") != "1")
 136                                 throw new ArgumentException (
 137                                         Locale.GetText ("The argument is not valid"));
 138
 139                         flags = (SecurityPermissionFlag) Enum.Parse (
 140                                 typeof (SecurityPermissionFlag), e.Attribute ("Flags"));
 141                 }
 142
 143                 public override SecurityElement ToXml ()
 144                 {
 145                         SecurityElement e = new SecurityElement ("IPermission");
 146                         e.AddAttribute ("class", GetType ().AssemblyQualifiedName);
 147                         e.AddAttribute ("version", "1");
 148
 149                         e.AddAttribute ("Flags", flags.ToString ());
 150
 151                         return e;
 152                 }
 153
 154                 // IBuiltInPermission
 155                 int IBuiltInPermission.GetTokenIndex ()
 156                 {
 157                         return 6;
 158                 }
 159         }
 160 }