class/System.Drawing/System.Drawing.Printing/PrintingPermission.cs

   1 //
   2 // System.Drawing.PrintingPermission.cs
   3 //
   4 // Authors:
   5 //      Dennis Hayes (dennish@Raytek.com)
   6 //      Herve Poussineau (hpoussineau@fr.st)
   7 //      Sebastien Pouliot  <sebastien@ximian.com>
   8 //
   9 // (C) 2002 Ximian, Inc
  10 // Copyright (C) 2004 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.Security;
  34 using System.Security.Permissions;
  35
  36 namespace System.Drawing.Printing {
  37
  38         [Serializable]
  39         public sealed class PrintingPermission : CodeAccessPermission, IUnrestrictedPermission {
  40
  41                 private const int version = 1;
  42
  43                 private PrintingPermissionLevel _Level;
  44
  45                 public PrintingPermission (PermissionState state)
  46                 {
  47                         if (CheckPermissionState (state, true) == PermissionState.Unrestricted)
  48                                 _Level = PrintingPermissionLevel.AllPrinting;
  49                 }
  50
  51                 public PrintingPermission (PrintingPermissionLevel printingLevel)
  52                 {
  53                         Level = printingLevel;
  54                 }
  55
  56                 // properties
  57
  58                 public PrintingPermissionLevel Level{
  59                         get { return _Level; }
  60                         set {
  61                                 if (!Enum.IsDefined (typeof (PrintingPermissionLevel), value)) {
  62                                         string msg = Locale.GetText ("Invalid enum {0}");
  63                                         throw new ArgumentException (String.Format (msg, value), "Level");
  64                                 }
  65                                  _Level = value;
  66                         }
  67                 }
  68
  69                 // methods
  70
  71                 public override IPermission Copy ()
  72                 {
  73                         return new PrintingPermission (this.Level);
  74                 }
  75
  76                 public override void FromXml (SecurityElement esd)
  77                 {
  78                         CheckSecurityElement (esd, "esd", version, version);
  79                         // Note: we do not (yet) care about the return value
  80                         // as we only accept version 1 (min/max values)
  81
  82                         if (IsUnrestricted (esd))
  83                                 _Level = PrintingPermissionLevel.AllPrinting;
  84                         else {
  85                                 string level = esd.Attribute ("Level");
  86                                 if (level != null) {
  87                                         _Level = (PrintingPermissionLevel) Enum.Parse (
  88                                                 typeof (PrintingPermissionLevel), level);
  89                                 }
  90                                 else
  91                                         _Level = PrintingPermissionLevel.NoPrinting;
  92                         }
  93                 }
  94
  95                 public override IPermission Intersect (IPermission target)
  96                 {
  97                         PrintingPermission pp = Cast (target);
  98                         if ((pp == null) || IsEmpty () || pp.IsEmpty ())
  99                                 return null;
 100
 101                         PrintingPermissionLevel level = (_Level <= pp.Level) ? _Level : pp.Level;
 102                         return new PrintingPermission (level);
 103                 }
 104
 105                 public override bool IsSubsetOf (IPermission target)
 106                 {
 107                         PrintingPermission pp = Cast (target);
 108                         if (pp == null)
 109                                 return IsEmpty ();
 110
 111                         return (_Level <= pp.Level);
 112                 }
 113
 114                 public bool IsUnrestricted ()
 115                 {
 116                         return (_Level == PrintingPermissionLevel.AllPrinting);
 117                 }
 118
 119                 public override SecurityElement ToXml ()
 120                 {
 121                         SecurityElement se = Element (version);
 122                         if (IsUnrestricted ())
 123                                 se.AddAttribute ("Unrestricted", "true");
 124                         else
 125                                 se.AddAttribute ("Level", _Level.ToString ());
 126                         return se;
 127                 }
 128
 129                 public override IPermission Union (IPermission target)
 130                 {
 131                         PrintingPermission pp = Cast (target);
 132                         if (pp == null)
 133                                 return new PrintingPermission (_Level);
 134                         if (IsUnrestricted () || pp.IsUnrestricted ())
 135                                 return new PrintingPermission (PermissionState.Unrestricted);
 136                         if (IsEmpty () && pp.IsEmpty ())
 137                                 return null;
 138
 139                         PrintingPermissionLevel level = (_Level > pp.Level) ? _Level : pp.Level;
 140                         return new PrintingPermission (level);
 141                 }
 142
 143                 // Internal helpers methods
 144
 145                 private bool IsEmpty ()
 146                 {
 147                         return (_Level == PrintingPermissionLevel.NoPrinting);
 148                 }
 149
 150                 private PrintingPermission Cast (IPermission target)
 151                 {
 152                         if (target == null)
 153                                 return null;
 154
 155                         PrintingPermission pp = (target as PrintingPermission);
 156                         if (pp == null) {
 157                                 ThrowInvalidPermission (target, typeof (PrintingPermission));
 158                         }
 159
 160                         return pp;
 161                 }
 162
 163                 // NOTE: The following static methods should be moved out to a (static?) class
 164                 // if (ever) System.Drawing.dll gets more than one permission in it's assembly.
 165
 166                 // snippet moved from FileIOPermission (nickd) to be reused in all derived classes
 167                 internal SecurityElement Element (int version)
 168                 {
 169                         SecurityElement se = new SecurityElement ("IPermission");
 170                         Type type = this.GetType ();
 171                         se.AddAttribute ("class", type.FullName + ", " + type.Assembly.ToString ().Replace ('\"', '\''));
 172                         se.AddAttribute ("version", version.ToString ());
 173                         return se;
 174                 }
 175
 176                 internal static PermissionState CheckPermissionState (PermissionState state, bool allowUnrestricted)
 177                 {
 178                         string msg;
 179                         switch (state) {
 180                         case PermissionState.None:
 181                                 break;
 182                         case PermissionState.Unrestricted:
 183                                 if (!allowUnrestricted) {
 184                                         msg = Locale.GetText ("Unrestricted isn't not allowed for identity permissions.");
 185                                         throw new ArgumentException (msg, "state");
 186                                 }
 187                                 break;
 188                         default:
 189                                 msg = String.Format (Locale.GetText ("Invalid enum {0}"), state);
 190                                 throw new ArgumentException (msg, "state");
 191                         }
 192                         return state;
 193                 }
 194
 195                 // logic isn't identical to CodeAccessPermission.CheckSecurityElement - see unit tests
 196                 internal static int CheckSecurityElement (SecurityElement se, string parameterName, int minimumVersion, int maximumVersion)
 197                 {
 198                         if (se == null)
 199                                 throw new ArgumentNullException (parameterName);
 200
 201                         string c = se.Attribute ("class");
 202 #if NET_2_0
 203                         if (c == null) {
 204                                 string msg = Locale.GetText ("Missing 'class' attribute.");
 205                                 throw new ArgumentException (msg, parameterName);
 206                         }
 207 #else
 208                         if ((c == null) || (String.Compare (c, 0, "System.Drawing.Printing.PrintingPermission", 0, 42) != 0)) {
 209                                 string msg = Locale.GetText ("Wrong 'class' attribute.");
 210                                 throw new ArgumentException (msg, parameterName);
 211                         }
 212 #endif
 213                         // we assume minimum version if no version number is supplied
 214                         int version = minimumVersion;
 215                         string v = se.Attribute ("version");
 216                         if (v != null) {
 217                                 try {
 218                                         version = Int32.Parse (v);
 219                                 }
 220                                 catch (Exception e) {
 221                                         string msg = Locale.GetText ("Couldn't parse version from '{0}'.");
 222                                         msg = String.Format (msg, v);
 223                                         throw new ArgumentException (msg, parameterName, e);
 224                                 }
 225                         }
 226 #if !NET_2_0
 227                         else {
 228                                 string msg = Locale.GetText ("Missing 'version' attribute.");
 229                                 throw new ArgumentException (msg, parameterName);
 230                         }
 231 #endif
 232
 233                         if ((version < minimumVersion) || (version > maximumVersion)) {
 234                                 string msg = Locale.GetText ("Unknown version '{0}', expected versions between ['{1}','{2}'].");
 235                                 msg = String.Format (msg, version, minimumVersion, maximumVersion);
 236                                 throw new ArgumentException (msg, parameterName);
 237                         }
 238                         return version;
 239                 }
 240
 241                 // must be called after CheckSecurityElement (i.e. se != null)
 242                 internal static bool IsUnrestricted (SecurityElement se)
 243                 {
 244                         string value = se.Attribute ("Unrestricted");
 245                         if (value == null)
 246                                 return false;
 247                         return (String.Compare (value, Boolean.TrueString, true, CultureInfo.InvariantCulture) == 0);
 248                 }
 249
 250                 internal static void ThrowInvalidPermission (IPermission target, Type expected)
 251                 {
 252                         string msg = Locale.GetText ("Invalid permission type '{0}', expected type '{1}'.");
 253                         msg = String.Format (msg, target.GetType (), expected);
 254                         throw new ArgumentException (msg, "target");
 255                 }
 256         }
 257 }