mcs/class/System.Data/System.Data.Common/PermissionHelper.cs

   1 //
   2 // System.Data.Common.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 using System.Security;
  31 using System.Security.Permissions;
  32
  33 namespace System.Data.Common {
  34
  35         // NOTE: This version of PermissionHelper was customized for System.Data
  36
  37         internal sealed class PermissionHelper {
  38
  39                 // snippet moved from FileIOPermission (nickd) to be reused in all derived classes
  40                 internal static SecurityElement Element (Type type, int version)
  41                 {
  42                         SecurityElement se = new SecurityElement ("IPermission");
  43                         se.AddAttribute ("class", type.FullName + ", " + type.Assembly.ToString ().Replace ('\"', '\''));
  44                         se.AddAttribute ("version", version.ToString ());
  45                         return se;
  46                 }
  47
  48                 internal static PermissionState CheckPermissionState (PermissionState state, bool allowUnrestricted)
  49                 {
  50                         string msg;
  51                         switch (state) {
  52                         case PermissionState.None:
  53                                 break;
  54                         case PermissionState.Unrestricted:
  55                                 if (!allowUnrestricted) {
  56                                         msg = Locale.GetText ("Unrestricted isn't not allowed for identity permissions.");
  57                                         throw new ArgumentException (msg, "state");
  58                                 }
  59                                 break;
  60                         default:
  61                                 msg = String.Format (Locale.GetText ("Invalid enum {0}"), state);
  62                                 throw new ArgumentOutOfRangeException (msg, "state");
  63                         }
  64                         return state;
  65                 }
  66
  67                 internal static int CheckSecurityElement (SecurityElement se, string parameterName, int minimumVersion, int maximumVersion)
  68                 {
  69                         if (se == null)
  70                                 throw new ArgumentNullException (parameterName);
  71
  72                         if (se.Tag != "IPermission") {
  73                                 string msg = Locale.GetText ("Invalid tag '{0}' expected 'IPermission'.");
  74                                 throw new ArgumentException (String.Format (msg, se.Tag), parameterName);
  75                         }
  76
  77                         // we assume minimum version if no version number is supplied
  78                         int version = minimumVersion;
  79                         string v = se.Attribute ("version");
  80                         if (v != null) {
  81                                 try {
  82                                         version = Int32.Parse (v);
  83                                 }
  84                                 catch (Exception e) {
  85                                         string msg = Locale.GetText ("Couldn't parse version from '{0}'.");
  86                                         msg = String.Format (msg, v);
  87                                         throw new ArgumentException (msg, parameterName, e);
  88                                 }
  89                         }
  90
  91                         if ((version < minimumVersion) || (version > maximumVersion)) {
  92                                 string msg = Locale.GetText ("Unknown version '{0}', expected versions between ['{1}','{2}'].");
  93                                 msg = String.Format (msg, version, minimumVersion, maximumVersion);
  94                                 throw new ArgumentException (msg, parameterName);
  95                         }
  96                         return version;
  97                 }
  98
  99                 // must be called after CheckSecurityElement (i.e. se != null)
 100                 internal static bool IsUnrestricted (SecurityElement se)
 101                 {
 102                         string value = se.Attribute ("Unrestricted");
 103                         if (value == null)
 104                                 return false;
 105                         return (String.Compare (value, Boolean.TrueString, true, CultureInfo.InvariantCulture) == 0);
 106                 }
 107
 108                 internal static void ThrowInvalidPermission (IPermission target, Type expected)
 109                 {
 110                         string msg = Locale.GetText ("Invalid permission type '{0}', expected type '{1}'.");
 111                         msg = String.Format (msg, target.GetType (), expected);
 112                         throw new ArgumentException (msg, "target");
 113                 }
 114         }
 115 }