mcs/class/corlib/System.Security.Permissions/EnvironmentPermission.cs

   1 //
   2 // System.Security.Permissions.EnvironmentPermission.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 Copyright (C) 2003 Motus Technologies (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.Collections;
  33 using System.Runtime.InteropServices;
  34 using System.Text;
  35 \r
  36 namespace System.Security.Permissions {\r
  37 \r
  38 #if NET_2_0
  39         [ComVisible (true)]
  40 #endif
  41         [Serializable]
  42         public sealed class EnvironmentPermission : CodeAccessPermission, IUnrestrictedPermission, IBuiltInPermission {
  43
  44                 #region Fields
  45
  46                 private const int version = 1;
  47
  48                 EnvironmentPermissionAccess flags;
  49                 PermissionState _state;
  50                 ArrayList readList;
  51                 ArrayList writeList;
  52
  53                 #endregion // Fields
  54
  55                 #region Constructors
  56
  57                 public EnvironmentPermission (PermissionState state) : base ()
  58                 {
  59                         _state = CheckPermissionState (state, true);
  60                         readList = new ArrayList ();
  61                         writeList = new ArrayList ();
  62                 }
  63
  64                 public EnvironmentPermission (EnvironmentPermissionAccess flag, string pathList) : base ()
  65                 {
  66                         readList = new ArrayList ();
  67                         writeList = new ArrayList ();
  68                         SetPathList (flag, pathList);
  69                 }
  70
  71                 #endregion // Constructors
  72
  73                 #region Methods
  74
  75                 public void AddPathList (EnvironmentPermissionAccess flag, string pathList)
  76                 {
  77                         if (pathList == null)
  78                                 throw new ArgumentNullException ("pathList");
  79
  80                         string[] paths;
  81                         switch (flag) {
  82                                 case EnvironmentPermissionAccess.AllAccess:
  83                                         paths = pathList.Split (';');
  84                                         foreach (string path in paths) {
  85                                                 if (!readList.Contains (path))
  86                                                         readList.Add (path);
  87                                                 if (!writeList.Contains (path))
  88                                                         writeList.Add (path);
  89                                         }
  90                                         break;
  91                                 case EnvironmentPermissionAccess.NoAccess:
  92                                         // ??? unit tests doesn't show removal using NoAccess ???
  93                                         break;
  94                                 case EnvironmentPermissionAccess.Read:
  95                                         paths = pathList.Split (';');
  96                                         foreach (string path in paths) {
  97                                                 if (!readList.Contains (path))
  98                                                         readList.Add (path);
  99                                         }
 100                                         break;
 101                                 case EnvironmentPermissionAccess.Write:
 102                                         paths = pathList.Split (';');
 103                                         foreach (string path in paths) {
 104                                                 if (!writeList.Contains (path))
 105                                                         writeList.Add (path);
 106                                         }
 107                                         break;
 108                                 default:
 109                                         ThrowInvalidFlag (flag, false);
 110                                         break;
 111                         }
 112                 }
 113
 114                 public override IPermission Copy ()
 115                 {
 116                         EnvironmentPermission ep = new EnvironmentPermission (_state);
 117                         string path = GetPathList (EnvironmentPermissionAccess.Read);
 118                         if (path != null)
 119                                 ep.SetPathList (EnvironmentPermissionAccess.Read, path);
 120                         path = GetPathList (EnvironmentPermissionAccess.Write);
 121                         if (path != null)
 122                                 ep.SetPathList (EnvironmentPermissionAccess.Write, path);
 123                         return ep;
 124                 }
 125
 126                 public override void FromXml (SecurityElement esd)
 127                 {
 128                         // General validation in CodeAccessPermission
 129                         CheckSecurityElement (esd, "esd", version, version);
 130                         // Note: we do not (yet) care about the return value
 131                         // as we only accept version 1 (min/max values)
 132
 133                         if (IsUnrestricted (esd))
 134                                 _state = PermissionState.Unrestricted;
 135
 136                         string read = esd.Attribute ("Read");
 137                         if ((read != null) && (read.Length > 0))
 138                                 SetPathList (EnvironmentPermissionAccess.Read, read);
 139
 140                         string write = esd.Attribute ("Write");
 141                         if ((write != null) && (write.Length > 0))
 142                                 SetPathList (EnvironmentPermissionAccess.Write, write);
 143                 }
 144
 145                 public string GetPathList (EnvironmentPermissionAccess flag)
 146                 {
 147                         switch (flag) {
 148                                 case EnvironmentPermissionAccess.AllAccess:
 149                                 case EnvironmentPermissionAccess.NoAccess:
 150                                         ThrowInvalidFlag (flag, true);
 151                                         break;
 152                                 case EnvironmentPermissionAccess.Read:
 153                                         return GetPathList (readList);
 154                                 case EnvironmentPermissionAccess.Write:
 155                                         return GetPathList (writeList);
 156                                 default:
 157                                         ThrowInvalidFlag (flag, false);
 158                                         break;
 159                         }
 160                         return null; // never reached
 161                 }
 162
 163                 public override IPermission Intersect (IPermission target)
 164                 {
 165                         EnvironmentPermission ep = Cast (target);
 166                         if (ep == null)
 167                                 return null;
 168
 169                         if (IsUnrestricted ())
 170                                 return ep.Copy ();
 171                         if (ep.IsUnrestricted ())
 172                                 return Copy ();
 173
 174                         int n = 0;
 175                         EnvironmentPermission result = new EnvironmentPermission (PermissionState.None);
 176                         string readTarget = ep.GetPathList (EnvironmentPermissionAccess.Read);
 177                         if (readTarget != null) {
 178                                 string[] targets = readTarget.Split (';');
 179                                 foreach (string t in targets) {
 180                                         if (readList.Contains (t)) {
 181                                                 result.AddPathList (EnvironmentPermissionAccess.Read, t);
 182                                                 n++;
 183                                         }
 184                                 }
 185                         }
 186
 187                         string writeTarget = ep.GetPathList (EnvironmentPermissionAccess.Write);
 188                         if (writeTarget != null) {
 189                                 string[] targets = writeTarget.Split (';');
 190                                 foreach (string t in targets) {
 191                                         if (writeList.Contains (t)) {
 192                                                 result.AddPathList (EnvironmentPermissionAccess.Write, t);
 193                                                 n++;
 194                                         }
 195                                 }
 196                         }
 197                         return ((n > 0) ? result : null);
 198                 }
 199
 200                 public override bool IsSubsetOf (IPermission target)
 201                 {
 202                         EnvironmentPermission ep = Cast (target);
 203                         if (ep == null)
 204                                 return false;
 205
 206                         if (IsUnrestricted ())
 207                                 return ep.IsUnrestricted ();
 208                         else if (ep.IsUnrestricted ())
 209                                 return true;
 210
 211                         foreach (string s in readList) {
 212                                 if (!ep.readList.Contains (s))
 213                                         return false;
 214                         }
 215
 216                         foreach (string s in writeList) {
 217                                 if (!ep.writeList.Contains (s))
 218                                         return false;
 219                         }
 220
 221                         return true;
 222                 }
 223
 224                 public bool IsUnrestricted ()
 225                 {
 226                         return (_state == PermissionState.Unrestricted);
 227                 }
 228
 229                 public void SetPathList (EnvironmentPermissionAccess flag, string pathList)
 230                 {
 231                         if (pathList == null)
 232                                 throw new ArgumentNullException ("pathList");
 233                         string[] paths;
 234                         switch (flag) {
 235                                 case EnvironmentPermissionAccess.AllAccess:
 236                                         readList.Clear ();
 237                                         writeList.Clear ();
 238                                         paths = pathList.Split (';');
 239                                         foreach (string path in paths) {
 240                                                 readList.Add (path);
 241                                                 writeList.Add (path);
 242                                         }
 243                                         break;
 244                                 case EnvironmentPermissionAccess.NoAccess:
 245                                         // ??? unit tests doesn't show removal using NoAccess ???
 246                                         break;
 247                                 case EnvironmentPermissionAccess.Read:
 248                                         readList.Clear ();
 249                                         paths = pathList.Split (';');
 250                                         foreach (string path in paths) {
 251                                                 readList.Add (path);
 252                                         }
 253                                         break;
 254                                 case EnvironmentPermissionAccess.Write:
 255                                         writeList.Clear ();
 256                                         paths = pathList.Split (';');
 257                                         foreach (string path in paths) {
 258                                                 writeList.Add (path);
 259                                         }
 260                                         break;
 261                                 default:
 262                                         ThrowInvalidFlag (flag, false);
 263                                         break;
 264                         }
 265                 }
 266
 267                 public override SecurityElement ToXml ()
 268                 {
 269                         SecurityElement se = Element (version);
 270
 271                         if (_state == PermissionState.Unrestricted) {
 272                                 se.AddAttribute ("Unrestricted", "true");
 273                         }
 274                         else {
 275                                 string path = GetPathList (EnvironmentPermissionAccess.Read);
 276                                 if (path != null)
 277                                         se.AddAttribute ("Read", path);
 278                                 path = GetPathList (EnvironmentPermissionAccess.Write);
 279                                 if (path != null)
 280                                         se.AddAttribute ("Write", path);
 281                         }
 282                         return se;
 283                 }
 284
 285                 public override IPermission Union (IPermission other)
 286                 {
 287                         EnvironmentPermission ep = Cast (other);
 288                         if (ep == null)
 289                                 return Copy ();
 290
 291                         if (IsUnrestricted () || ep.IsUnrestricted ())
 292                                 return new EnvironmentPermission (PermissionState.Unrestricted);
 293
 294                         if (IsEmpty () && ep.IsEmpty ())
 295                                 return null;
 296
 297                         EnvironmentPermission result = (EnvironmentPermission) Copy ();
 298                         string path = ep.GetPathList (EnvironmentPermissionAccess.Read);
 299                         if (path != null)
 300                                 result.AddPathList (EnvironmentPermissionAccess.Read, path);
 301                         path = ep.GetPathList (EnvironmentPermissionAccess.Write);
 302                         if (path != null)
 303                                 result.AddPathList (EnvironmentPermissionAccess.Write, path);
 304                         return result;
 305                 }
 306
 307                 // IBuiltInPermission
 308                 int IBuiltInPermission.GetTokenIndex ()
 309                 {
 310                         return (int) BuiltInToken.Environment;
 311                 }
 312
 313                 // helpers
 314
 315                 private bool IsEmpty ()
 316                 {
 317                         return ((_state == PermissionState.None) && (readList.Count == 0) && (writeList.Count == 0));
 318                 }
 319
 320                 private EnvironmentPermission Cast (IPermission target)
 321                 {
 322                         if (target == null)
 323                                 return null;
 324
 325                         EnvironmentPermission ep = (target as EnvironmentPermission);
 326                         if (ep == null) {
 327                                 ThrowInvalidPermission (target, typeof (EnvironmentPermission));
 328                         }
 329
 330                         return ep;
 331                 }
 332
 333                 internal void ThrowInvalidFlag (EnvironmentPermissionAccess flag, bool context)
 334                 {
 335                         string msg = null;
 336                         if (context)
 337                                 msg = Locale.GetText ("Unknown flag '{0}'.");
 338                         else
 339                                 msg = Locale.GetText ("Invalid flag '{0}' in this context.");
 340                         throw new ArgumentException (String.Format (msg, flag), "flag");
 341                 }
 342
 343                 private string GetPathList (ArrayList list)
 344                 {
 345                         if (IsUnrestricted ())
 346                                 return String.Empty;
 347 #if NET_2_0
 348                         if (list.Count == 0)
 349                                 return String.Empty;
 350 #else
 351                         if (list.Count == 0)
 352                                 return null;
 353 #endif
 354                         StringBuilder sb = new StringBuilder ();
 355                         foreach (string path in list) {
 356                                 sb.Append (path);
 357                                 sb.Append (";");
 358                         }
 359
 360                         string result = sb.ToString ();
 361                         // remove last ';'
 362                         int n = result.Length;
 363                         if (n > 0)
 364                                 return result.Substring (0, n - 1);
 365 #if NET_2_0
 366                         return String.Empty;
 367 #else
 368                         return ((_state == PermissionState.Unrestricted) ? String.Empty : null);
 369 #endif
 370                 }
 371
 372                 #endregion // Methods
 373         }
 374 }