class/corlib/System.Security/PermissionBuilder.cs

   1 //
   2 // System.Security.PermissionBuilder.cs
   3 //
   4 // Author:
   5 //      Sebastien Pouliot  <sebastien@ximian.com>
   6 //
   7 // Copyright (C) 2005 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.Security.Permissions;
  30
  31 namespace System.Security {
  32
  33         internal static class PermissionBuilder {
  34                 private static object[] psNone = new object [1] { PermissionState.None };
  35
  36                 // can be used to create an empty or an unrestricted permission from any valid type
  37                 static public IPermission Create (string fullname, PermissionState state)
  38                 {
  39                         if (fullname == null)
  40                                 throw new ArgumentNullException ("fullname");
  41
  42                         SecurityElement se = new SecurityElement ("IPermission");
  43                         se.AddAttribute ("class", fullname);
  44                         se.AddAttribute ("version", "1");
  45                         if (state == PermissionState.Unrestricted)
  46                                 se.AddAttribute ("Unrestricted", "true");
  47
  48                         return CreatePermission (fullname, se);
  49                 }
  50
  51                 static public IPermission Create (SecurityElement se)
  52                 {
  53                         if (se == null)
  54                                 throw new ArgumentNullException ("se");
  55
  56                         string className = se.Attribute ("class");
  57                         if ((className == null) || (className.Length == 0))
  58                                 throw new ArgumentException ("class");
  59
  60                         return CreatePermission (className, se);
  61                 }
  62
  63                 // to use in case where the "class" attribute isn't a fully qualified class name
  64                 static public IPermission Create (string fullname, SecurityElement se)
  65                 {
  66                         if (fullname == null)
  67                                 throw new ArgumentNullException ("fullname");
  68                         if (se == null)
  69                                 throw new ArgumentNullException ("se");
  70
  71                         return CreatePermission (fullname, se);
  72                 }
  73
  74                 static public IPermission Create (Type type)
  75                 {
  76                         // note: unification is handled in lower levels
  77                         // http://blogs.msdn.com/shawnfa/archive/2004/08/05/209320.aspx
  78                         return (IPermission) Activator.CreateInstance (type, psNone);
  79                 }
  80
  81                 // internal stuff
  82
  83                 internal static IPermission CreatePermission (string fullname, SecurityElement se)
  84                 {
  85                         Type classType = Type.GetType (fullname);
  86                         if (classType == null) {
  87                                 string msg = Locale.GetText ("Can't create an instance of permission class {0}.");
  88                                 throw new TypeLoadException (String.Format (msg, fullname));
  89                         }
  90                         IPermission p = Create (classType);
  91                         p.FromXml (se);
  92                         return p;
  93                 }
  94         }
  95 }