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

   1 //
   2 // System.Security.Permissions.ReflectionPermission.cs
   3 //
   4 // Authors:
   5 //      Tim Coleman <tim@timcoleman.com>
   6 //      Sebastien Pouliot  <sebastien@ximian.com>
   7 //
   8 // Copyright (C) 2002, Tim Coleman
   9 // Portions (C) 2003 Motus Technologies Inc. (http://www.motus.com)
  10 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 using System.Globalization;
  33 using System.Runtime.InteropServices;
  34
  35 namespace System.Security.Permissions {
  36
  37         [ComVisible (true)]
  38         [Serializable]
  39         public sealed class ReflectionPermission : CodeAccessPermission, IUnrestrictedPermission, IBuiltInPermission {
  40
  41                 private const int version = 1;
  42
  43                 ReflectionPermissionFlag flags;
  44
  45
  46                 public ReflectionPermission (PermissionState state)
  47                 {
  48                         if (CheckPermissionState (state, true) == PermissionState.Unrestricted)
  49                                 flags = ReflectionPermissionFlag.AllFlags;
  50                         else
  51                                 flags = ReflectionPermissionFlag.NoFlags;
  52                 }
  53
  54                 public ReflectionPermission (ReflectionPermissionFlag flag)
  55                 {
  56                         // reuse validation by the Flags property
  57                         Flags = flag;
  58                 }
  59
  60
  61                 public ReflectionPermissionFlag Flags {
  62                         get { return flags; }
  63                         set {
  64                                 const ReflectionPermissionFlag all_flags = ReflectionPermissionFlag.AllFlags | ReflectionPermissionFlag.RestrictedMemberAccess;
  65
  66                                 if ((value & all_flags) != value) {
  67                                         string msg = String.Format (Locale.GetText ("Invalid flags {0}"), value);
  68                                         throw new ArgumentException (msg, "ReflectionPermissionFlag");
  69                                 }
  70
  71                                 flags = value;
  72                         }
  73                 }
  74
  75
  76                 public override IPermission Copy ()
  77                 {
  78                         return new ReflectionPermission (flags);
  79                 }
  80
  81                 public override void FromXml (SecurityElement esd)
  82                 {
  83                         // General validation in CodeAccessPermission
  84                         CheckSecurityElement (esd, "esd", version, version);
  85                         // Note: we do not (yet) care about the return value
  86                         // as we only accept version 1 (min/max values)
  87
  88                         if (IsUnrestricted (esd)) {
  89                                 flags = ReflectionPermissionFlag.AllFlags;
  90                         }
  91                         else {
  92                                 flags = ReflectionPermissionFlag.NoFlags;
  93                                 string xmlFlags = (esd.Attributes ["Flags"] as string);
  94                                 if (xmlFlags.IndexOf ("MemberAccess") >= 0)
  95                                         flags |= ReflectionPermissionFlag.MemberAccess;
  96                                 if (xmlFlags.IndexOf ("ReflectionEmit") >= 0)
  97                                         flags |= ReflectionPermissionFlag.ReflectionEmit;
  98                                 if (xmlFlags.IndexOf ("TypeInformation") >= 0)
  99                                         flags |= ReflectionPermissionFlag.TypeInformation;
 100                         }
 101                 }
 102
 103                 public override IPermission Intersect (IPermission target)
 104                 {
 105                         ReflectionPermission rp = Cast (target);
 106                         if (rp == null)
 107                                 return null;
 108
 109                         if (IsUnrestricted ()) {
 110                                 if (rp.Flags == ReflectionPermissionFlag.NoFlags)
 111                                         return null;
 112                                 else
 113                                         return rp.Copy ();
 114                         }
 115                         if (rp.IsUnrestricted ()) {
 116                                 if (flags == ReflectionPermissionFlag.NoFlags)
 117                                         return null;
 118                                 else
 119                                         return Copy ();
 120                         }
 121
 122                         ReflectionPermission p = (ReflectionPermission) rp.Copy ();
 123                         p.Flags &= flags;
 124                         return ((p.Flags == ReflectionPermissionFlag.NoFlags) ? null : p);
 125                 }
 126
 127                 public override bool IsSubsetOf (IPermission target)
 128                 {
 129                         ReflectionPermission rp = Cast (target);
 130                         if (rp == null)
 131                                 return (flags == ReflectionPermissionFlag.NoFlags);
 132
 133                         if (IsUnrestricted ())
 134                                 return rp.IsUnrestricted ();
 135                         else if (rp.IsUnrestricted ())
 136                                 return true;
 137
 138                         return ((flags & rp.Flags) == flags);
 139                 }
 140
 141                 public bool IsUnrestricted ()
 142                 {
 143                         return (flags == ReflectionPermissionFlag.AllFlags);
 144                 }
 145
 146                 public override SecurityElement ToXml ()
 147                 {
 148                         SecurityElement se = Element (version);
 149                         if (IsUnrestricted ()) {
 150                                 se.AddAttribute ("Unrestricted", "true");
 151                         }
 152                         else {
 153                                 if (flags == ReflectionPermissionFlag.NoFlags)
 154                                         se.AddAttribute ("Flags", "NoFlags");
 155                                 else if ((flags & ReflectionPermissionFlag.AllFlags) == ReflectionPermissionFlag.AllFlags)
 156                                         se.AddAttribute ("Flags", "AllFlags");
 157                                 else {
 158                                         string xmlFlags = "";
 159                                         if ((flags & ReflectionPermissionFlag.MemberAccess) == ReflectionPermissionFlag.MemberAccess)
 160                                                 xmlFlags = "MemberAccess";
 161                                         if ((flags & ReflectionPermissionFlag.ReflectionEmit) == ReflectionPermissionFlag.ReflectionEmit) {
 162                                                 if (xmlFlags.Length > 0)
 163                                                         xmlFlags += ", ";
 164                                                 xmlFlags += "ReflectionEmit";
 165                                         }
 166                                         if ((flags & ReflectionPermissionFlag.TypeInformation) == ReflectionPermissionFlag.TypeInformation) {
 167                                                 if (xmlFlags.Length > 0)
 168                                                         xmlFlags += ", ";
 169                                                 xmlFlags += "TypeInformation";
 170                                         }
 171                                         se.AddAttribute ("Flags", xmlFlags);
 172                                 }
 173                         }
 174                         return se;
 175                 }
 176
 177                 public override IPermission Union (IPermission other)
 178                 {
 179                         ReflectionPermission rp = Cast (other);
 180                         if (other == null)
 181                                 return Copy ();
 182
 183                         if (IsUnrestricted () || rp.IsUnrestricted ())
 184                                 return new ReflectionPermission (PermissionState.Unrestricted);
 185
 186                         ReflectionPermission p = (ReflectionPermission) rp.Copy ();
 187                         p.Flags |= flags;
 188                         return p;
 189                 }
 190
 191                 // IBuiltInPermission
 192                 int IBuiltInPermission.GetTokenIndex ()
 193                 {
 194                         return (int) BuiltInToken.Reflection;
 195                 }
 196
 197                 // helpers
 198
 199                 private ReflectionPermission Cast (IPermission target)
 200                 {
 201                         if (target == null)
 202                                 return null;
 203
 204                         ReflectionPermission rp = (target as ReflectionPermission);
 205                         if (rp == null) {
 206                                 ThrowInvalidPermission (target, typeof (ReflectionPermission));
 207                         }
 208
 209                         return rp;
 210                 }
 211         }
 212 }