mcs/class/System/System.Security.Permissions/PermissionHelper.cs

   1 //
   2 // System.Security.Permissions.PermissionHelper.cs
   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 using System.Globalization;
  30
  31 namespace System.Security.Permissions {
  32
  33         internal sealed class PermissionHelper {
  34
  35                 // snippet moved from FileIOPermission (nickd) to be reused in all derived classes
  36                 internal static SecurityElement Element (Type type, int version)
  37                 {
  38                         SecurityElement se = new SecurityElement ("IPermission");
  39                         se.AddAttribute ("class", type.FullName + ", " + type.Assembly.ToString ().Replace ('\"', '\''));
  40                         se.AddAttribute ("version", version.ToString ());
  41                         return se;
  42                 }
  43
  44                 internal static PermissionState CheckPermissionState (PermissionState state, bool allowUnrestricted)
  45                 {
  46                         string msg;
  47                         switch (state) {
  48                         case PermissionState.None:
  49                                 break;
  50                         case PermissionState.Unrestricted:
  51                                 if (!allowUnrestricted) {
  52                                         msg = Locale.GetText ("Unrestricted isn't not allowed for identity permissions.");
  53                                         throw new ArgumentException (msg, "state");
  54                                 }
  55                                 break;
  56                         default:
  57                                 msg = String.Format (Locale.GetText ("Invalid enum {0}"), state);
  58                                 throw new ArgumentException (msg, "state");
  59                         }
  60                         return state;
  61                 }
  62
  63                 internal static int CheckSecurityElement (SecurityElement se, string parameterName, int minimumVersion, int maximumVersion)
  64                 {
  65                         if (se == null)
  66                                 throw new ArgumentNullException (parameterName);
  67
  68                         if (se.Attribute ("class") == null) {
  69                                 string msg = Locale.GetText ("Missing 'class' attribute.");
  70                                 throw new ArgumentException (msg, parameterName);
  71                         }
  72
  73                         // we assume minimum version if no version number is supplied
  74                         int version = minimumVersion;
  75                         string v = se.Attribute ("version");
  76                         if (v != null) {
  77                                 try {
  78                                         version = Int32.Parse (v);
  79                                 }
  80                                 catch (Exception e) {
  81                                         string msg = Locale.GetText ("Couldn't parse version from '{0}'.");
  82                                         msg = String.Format (msg, v);
  83                                         throw new ArgumentException (msg, parameterName, e);
  84                                 }
  85                         }
  86
  87                         if ((version < minimumVersion) || (version > maximumVersion)) {
  88                                 string msg = Locale.GetText ("Unknown version '{0}', expected versions between ['{1}','{2}'].");
  89                                 msg = String.Format (msg, version, minimumVersion, maximumVersion);
  90                                 throw new ArgumentException (msg, parameterName);
  91                         }
  92                         return version;
  93                 }
  94
  95                 // must be called after CheckSecurityElement (i.e. se != null)
  96                 internal static bool IsUnrestricted (SecurityElement se)
  97                 {
  98                         string value = se.Attribute ("Unrestricted");
  99                         if (value == null)
 100                                 return false;
 101                         return (String.Compare (value, Boolean.TrueString, true, CultureInfo.InvariantCulture) == 0);
 102                 }
 103
 104                 internal static void ThrowInvalidPermission (IPermission target, Type expected)
 105                 {
 106                         string msg = Locale.GetText ("Invalid permission type '{0}', expected type '{1}'.");
 107                         msg = String.Format (msg, target.GetType (), expected);
 108                         throw new ArgumentException (msg, "target");
 109                 }
 110         }
 111 }