mcs/class/corlib/System.Security/PermissionSet.cs

   1 //
   2 // System.Security.PermissionSet.cs
   3 //
   4 // Authors:
   5 //      Nick Drochak(ndrochak@gol.com)
   6 //      Sebastien Pouliot  <sebastien@ximian.com>
   7 //
   8 // (C) Nick Drochak
   9 // Portions (C) 2003, 2004 Motus Technologies Inc. (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.Diagnostics;
  34 using System.IO;
  35 using System.Reflection;
  36 using System.Runtime.InteropServices;
  37 using System.Runtime.Serialization;
  38 using System.Runtime.Serialization.Formatters.Binary;
  39 using System.Security.Permissions;
  40 using System.Security.Policy;
  41 using System.Text;
  42 using System.Threading;
  43
  44 namespace System.Security {
  45
  46         [Serializable]
  47         // Microsoft public key - i.e. only MS signed assembly can inherit from PermissionSet (1.x) or (2.0) FullTrust assemblies
  48         [StrongNameIdentityPermission (SecurityAction.InheritanceDemand, PublicKey="002400000480000094000000060200000024000052534131000400000100010007D1FA57C4AED9F0A32E84AA0FAEFD0DE9E8FD6AEC8F87FB03766C834C99921EB23BE79AD9D5DCC1DD9AD236132102900B723CF980957FC4E177108FC607774F29E8320E92EA05ECE4E821C0A5EFE8F1645C4C0C93C1AB99285D622CAA652C1DFAD63D745D6F2DE5F17E5EAF0FC4963D261C8A12436518206DC093344D5AD293")]
  49 #if NET_2_0
  50         [ComVisible (true)]
  51 #endif
  52         public class PermissionSet: ISecurityEncodable, ICollection, IEnumerable, IStackWalk, IDeserializationCallback {
  53
  54                 private const string tagName = "PermissionSet";
  55                 private const int version = 1;
  56                 private static object[] psUnrestricted = new object [1] { PermissionState.Unrestricted };
  57
  58                 private PermissionState state;
  59                 private ArrayList list;
  60                 private int _hashcode;
  61                 private PolicyLevel _policyLevel;
  62                 private bool _declsec;
  63                 private bool _readOnly;
  64                 private bool[] _ignored; // for asserts and non-CAS permissions
  65
  66                 // constructors
  67
  68                 // for PolicyLevel (to avoid validation duplication)
  69                 internal PermissionSet ()
  70                 {
  71                         list = new ArrayList ();
  72                 }
  73
  74                 public PermissionSet (PermissionState state) : this ()
  75                 {
  76                         this.state = CodeAccessPermission.CheckPermissionState (state, true);
  77                 }
  78
  79                 public PermissionSet (PermissionSet permSet) : this ()
  80                 {
  81                         // LAMESPEC: This would be handled by the compiler.  No way permSet is not a PermissionSet.
  82                         //if (!(permSet is PermissionSet))
  83                         //      throw new System.ArgumentException(); // permSet is not an instance of System.Security.PermissionSet.
  84                         if (permSet != null) {
  85                                 state = permSet.state;
  86                                 foreach (IPermission p in permSet.list)
  87                                         list.Add (p);
  88                         }
  89 #if !NET_2_0
  90                         else {
  91                                 state = PermissionState.Unrestricted;
  92                         }
  93 #endif
  94                 }
  95
  96                 internal PermissionSet (string xml)
  97                         : this ()
  98                 {
  99                         state = PermissionState.None;
 100                         if (xml != null) {
 101                                 SecurityElement se = SecurityElement.FromString (xml);
 102                                 FromXml (se);
 103                         }
 104                 }
 105
 106                 // Light version for creating a (non unrestricted) PermissionSet with
 107                 // a single permission. This allows to relax most validations.
 108                 internal PermissionSet (IPermission perm)
 109                         : this ()
 110                 {
 111                         if (perm != null) {
 112                                 // note: we do not copy IPermission like AddPermission
 113                                 list.Add (perm);
 114                         }
 115                 }
 116
 117                 // methods
 118
 119                 public virtual IPermission AddPermission (IPermission perm)
 120                 {
 121                         if ((perm == null) || _readOnly)
 122                                 return perm;
 123
 124                         // we don't add to an unrestricted permission set unless...
 125                         if (state == PermissionState.Unrestricted) {
 126 #if NET_2_0
 127                                 // identity permissions can be unrestricted under 2.x
 128                                 {
 129 #else
 130                                 // we're adding identity permission as they don't support unrestricted
 131                                 if (perm is IUnrestrictedPermission) {
 132 #endif
 133                                         // we return the union of the permission with unrestricted
 134                                         // which results in a permission of the same type initialized
 135                                         // with PermissionState.Unrestricted
 136                                         return (IPermission) Activator.CreateInstance (perm.GetType (), psUnrestricted);
 137                                 }
 138                         }
 139
 140                         // we can't add two permissions of the same type in a set
 141                         // so we remove an existing one, union with it and add it back
 142                         IPermission existing = RemovePermission (perm.GetType ());
 143                         if (existing != null) {
 144                                 perm = perm.Union (existing);
 145                         }
 146
 147                         // note: Add doesn't copy
 148                         list.Add (perm);
 149                         return perm;
 150                 }
 151
 152                 [MonoTODO ("Imperative mode isn't supported")]
 153                 [SecurityPermission (SecurityAction.Demand, Assertion = true)]
 154                 public virtual void Assert ()
 155                 {
 156                         int count = this.Count;
 157
 158                         // we (current frame) must have the permission to assert it to others
 159                         // otherwise we don't assert (but we don't throw an exception)
 160                         foreach (IPermission p in list) {
 161                                 // note: we ignore non-CAS permissions
 162                                 if (p is IStackWalk) {
 163                                         if (!SecurityManager.IsGranted (p)) {
 164                                                 return;
 165                                         }
 166                                 } else
 167                                         count--;
 168                         }
 169
 170                         // note: we must ignore the stack modifiers for the non-CAS permissions
 171                         if (SecurityManager.SecurityEnabled && (count > 0))
 172                                 throw new NotSupportedException ("Currently only declarative Assert are supported.");
 173                 }
 174
 175                 internal void Clear ()
 176                 {
 177                         list.Clear ();
 178                 }
 179
 180                 public virtual PermissionSet Copy ()
 181                 {
 182                         return new PermissionSet (this);
 183                 }
 184
 185                 public virtual void CopyTo (Array array, int index)
 186                 {
 187                         if (null == array)
 188                                 throw new ArgumentNullException ("array");
 189
 190                         if (list.Count > 0) {
 191                                 if (array.Rank > 1) {
 192                                         throw new ArgumentException (Locale.GetText (
 193                                                 "Array has more than one dimension"));
 194                                 }
 195                                 if (index < 0 || index >= array.Length) {
 196                                         throw new IndexOutOfRangeException ("index");
 197                                 }
 198
 199                                 list.CopyTo (array, index);
 200                         }
 201                 }
 202
 203                 public virtual void Demand ()
 204                 {
 205                         // Note: SecurityEnabled only applies to CAS permissions
 206                         // so we're not checking for it (yet)
 207                         if (IsEmpty ())
 208                                 return;
 209
 210                         int n = list.Count;
 211                         if ((_ignored == null) || (_ignored.Length != n)) {
 212                                 _ignored = new bool [n];
 213                         }
 214
 215                         bool call_cas_only = this.IsUnrestricted ();
 216                         // non CAS permissions (e.g. PrincipalPermission) do not requires a stack walk
 217                         for (int i = 0; i < n; i++) {
 218                                 CodeAccessPermission p = (CodeAccessPermission) list [i];
 219                                 Type t = p.GetType ();
 220                                 if (t.IsSubclassOf (typeof (CodeAccessPermission))) {
 221                                         _ignored [i] = false;
 222                                         call_cas_only = true;
 223                                 } else {
 224                                         _ignored [i] = true;
 225                                         p.Demand ();
 226                                 }
 227                         }
 228
 229                         // don't start the stack walk if
 230                         // - the permission set only contains non CAS permissions; or
 231                         // - security isn't enabled (applis only to CAS!)
 232                         if (call_cas_only && SecurityManager.SecurityEnabled)
 233                                 CasOnlyDemand (_declsec ? 5 : 3);
 234                 }
 235
 236                 // The number of frames to skip depends on who's calling
 237                 // - CodeAccessPermission.Demand (imperative)
 238                 // - PermissionSet.Demand (imperative)
 239                 // - SecurityManager.InternalDemand (declarative)
 240                 internal void CasOnlyDemand (int skip)
 241                 {
 242                         Assembly current = null;
 243                         AppDomain domain = null;
 244
 245                         if (_ignored == null) {
 246                                 // special case when directly called from CodeAccessPermission.Demand
 247                                 _ignored = new bool [list.Count];
 248                         }
 249
 250                         ArrayList frames = SecurityFrame.GetStack (skip);
 251                         if ((frames != null) && (frames.Count > 0)) {
 252                                 SecurityFrame first = ((SecurityFrame) frames [0]);
 253                                 current = first.Assembly;
 254                                 domain = first.Domain;
 255                                 // skip ourself, Demand and other security runtime methods
 256                                 foreach (SecurityFrame sf in frames) {
 257                                         if (ProcessFrame (sf, ref current, ref domain)) {
 258                                                 if (AllIgnored ())
 259                                                         return; // reached Assert
 260                                         }
 261                                 }
 262                                 SecurityFrame last = ((SecurityFrame) frames [frames.Count - 1]);
 263                                 CheckAssembly (current, last);
 264                                 CheckAppDomain (domain, last);
 265                         }
 266
 267                         // Is there a CompressedStack to handle ?
 268                         CompressedStack stack = Thread.CurrentThread.GetCompressedStack ();
 269                         if ((stack != null) && !stack.IsEmpty ()) {
 270                                 foreach (SecurityFrame frame in stack.List) {
 271                                         if (ProcessFrame (frame, ref current, ref domain)) {
 272                                                 if (AllIgnored ())
 273                                                         return; // reached Assert
 274                                         }
 275                                 }
 276                         }
 277                 }
 278
 279                 [MonoTODO ("Imperative mode isn't supported")]
 280                 public virtual void Deny ()
 281                 {
 282                         if (!SecurityManager.SecurityEnabled)
 283                                 return;
 284
 285                         foreach (IPermission p in list) {
 286                                 // note: we ignore non-CAS permissions
 287                                 if (p is IStackWalk) {
 288                                         throw new NotSupportedException ("Currently only declarative Deny are supported.");
 289                                 }
 290                         }
 291                 }
 292
 293                 public virtual void FromXml (SecurityElement et)
 294                 {
 295                         if (et == null)
 296                                 throw new ArgumentNullException ("et");
 297                         if (et.Tag != tagName) {
 298                                 string msg = String.Format ("Invalid tag {0} expected {1}", et.Tag, tagName);
 299                                 throw new ArgumentException (msg, "et");
 300                         }
 301
 302                         list.Clear ();
 303
 304                         if (CodeAccessPermission.IsUnrestricted (et)) {
 305                                 state = PermissionState.Unrestricted;
 306 #if NET_2_0
 307                                 // no need to continue for an unrestricted permission
 308                                 // because identity permissions now "supports" unrestricted
 309                                 return;
 310 #endif
 311                         } else {
 312                                 state = PermissionState.None;
 313                         }
 314
 315                         if (et.Children != null) {
 316                                 foreach (SecurityElement se in et.Children) {
 317                                         string className = se.Attribute ("class");
 318                                         if (className == null) {
 319                                                 throw new ArgumentException (Locale.GetText (
 320                                                         "No permission class is specified."));
 321                                         }
 322                                         if (Resolver != null) {
 323                                                 // policy class names do not have to be fully qualified
 324                                                 className = Resolver.ResolveClassName (className);
 325                                         }
 326
 327                                         list.Add (PermissionBuilder.Create (className, se));
 328                                 }
 329                         }
 330                 }
 331
 332                 public virtual IEnumerator GetEnumerator ()
 333                 {
 334                         return list.GetEnumerator ();
 335                 }
 336
 337                 public virtual bool IsSubsetOf (PermissionSet target)
 338                 {
 339 #if NET_2_0
 340                         // if target is empty we must be empty too
 341                         if ((target == null) || (target.IsEmpty ()))
 342                                 return this.IsEmpty ();
 343
 344                         // all permissions support unrestricted in 2.0
 345                         if (target.IsUnrestricted ())
 346                                 return true;
 347                         if (this.IsUnrestricted ())
 348                                 return false;
 349 #endif
 350                         if (this.IsUnrestricted () && ((target == null) || !target.IsUnrestricted ()))
 351                                 return false;
 352
 353                         // if each of our permission is (a) present and (b) a subset of target
 354                         foreach (IPermission p in list) {
 355 #if !NET_2_0
 356                                 if (target == null) {
 357                                         if (!p.IsSubsetOf (null))
 358                                                 return false;
 359                                 } else
 360 #endif
 361                                 {
 362                                         // non CAS permissions must be evaluated for unrestricted
 363                                         Type t = p.GetType ();
 364                                         IPermission i = null;
 365                                         if (target.IsUnrestricted () && (p is CodeAccessPermission) && (p is IUnrestrictedPermission)) {
 366                                                 i = (IPermission) Activator.CreateInstance (t, psUnrestricted);
 367                                         } else {
 368                                                 i = target.GetPermission (t);
 369                                         }
 370
 371                                         if (!p.IsSubsetOf (i))
 372                                                 return false; // not a subset (condition b)
 373                                 }
 374                         }
 375                         return true;
 376                 }
 377
 378                 [MonoTODO ("Imperative mode isn't supported")]
 379                 public virtual void PermitOnly ()
 380                 {
 381                         if (!SecurityManager.SecurityEnabled)
 382                                 return;
 383
 384                         foreach (IPermission p in list) {
 385                                 // note: we ignore non-CAS permissions
 386                                 if (p is IStackWalk) {
 387                                         throw new NotSupportedException ("Currently only declarative Deny are supported.");
 388                                 }
 389                         }
 390                 }
 391
 392                 public bool ContainsNonCodeAccessPermissions ()
 393                 {
 394                         if (list.Count > 0) {
 395                                 foreach (IPermission p in list) {
 396                                         if (! p.GetType ().IsSubclassOf (typeof (CodeAccessPermission)))
 397                                                 return true;
 398                                 }
 399                         }
 400                         return false;
 401                 }
 402
 403                 [MonoTODO ("little documentation in Fx 2.0 beta 1")]
 404                 public static byte[] ConvertPermissionSet (string inFormat, byte[] inData, string outFormat)
 405                 {
 406                         if (inFormat == null)
 407                                 throw new ArgumentNullException ("inFormat");
 408                         if (outFormat == null)
 409                                 throw new ArgumentNullException ("outFormat");
 410                         if (inData == null)
 411                                 return null;
 412
 413                         if (inFormat == outFormat)
 414                                 return inData;
 415
 416                         PermissionSet ps = null;
 417
 418                         if (inFormat == "BINARY") {
 419                                 if (outFormat.StartsWith ("XML")) {
 420                                         using (MemoryStream ms = new MemoryStream (inData)) {
 421                                                 BinaryFormatter formatter = new BinaryFormatter ();
 422                                                 ps = (PermissionSet) formatter.Deserialize (ms);
 423                                                 ms.Close ();
 424                                         }
 425                                         string xml = ps.ToString ();
 426                                         switch (outFormat) {
 427                                                 case "XML":
 428                                                 case "XMLASCII":
 429                                                         return Encoding.ASCII.GetBytes (xml);
 430                                                 case "XMLUNICODE":
 431                                                         return Encoding.Unicode.GetBytes (xml);
 432                                         }
 433                                 }
 434                         }
 435                         else if (inFormat.StartsWith ("XML")) {
 436                                 if (outFormat == "BINARY") {
 437                                         string xml = null;
 438                                         switch (inFormat) {
 439                                                 case "XML":
 440                                                 case "XMLASCII":
 441                                                         xml = Encoding.ASCII.GetString (inData);
 442                                                         break;
 443                                                 case "XMLUNICODE":
 444                                                         xml = Encoding.Unicode.GetString (inData);
 445                                                         break;
 446                                         }
 447                                         if (xml != null) {
 448                                                 ps = new PermissionSet (PermissionState.None);
 449                                                 ps.FromXml (SecurityElement.FromString (xml));
 450
 451                                                 MemoryStream ms = new MemoryStream ();
 452                                                 BinaryFormatter formatter = new BinaryFormatter ();
 453                                                 formatter.Serialize (ms, ps);
 454                                                 ms.Close ();
 455                                                 return ms.ToArray ();
 456                                         }
 457                                 }
 458                                 else if (outFormat.StartsWith ("XML")) {
 459                                         string msg = String.Format (Locale.GetText ("Can't convert from {0} to {1}"), inFormat, outFormat);
 460 #if NET_2_0
 461                                         throw new XmlSyntaxException (msg);
 462 #else
 463                                         throw new ArgumentException (msg);
 464 #endif
 465                                 }
 466                         }
 467                         else {
 468                                 // unknown inFormat, returns null
 469                                 return null;
 470                         }
 471                         // unknown outFormat, throw
 472                         throw new SerializationException (String.Format (Locale.GetText ("Unknown output format {0}."), outFormat));
 473                 }
 474
 475                 public virtual IPermission GetPermission (Type permClass)
 476                 {
 477                         if ((permClass == null) || (list.Count == 0))
 478                                 return null;
 479
 480                         foreach (object o in list) {
 481                                 if ((o != null) && o.GetType ().Equals (permClass))
 482                                         return (IPermission) o;
 483                         }
 484                         // it's normal to return null for unrestricted sets
 485                         return null;
 486                 }
 487
 488                 public virtual PermissionSet Intersect (PermissionSet other)
 489                 {
 490                         // no intersection possible
 491                         if ((other == null) || (other.IsEmpty ()) || (this.IsEmpty ()))
 492                                 return null;
 493
 494                         PermissionState state = PermissionState.None;
 495                         if (this.IsUnrestricted () && other.IsUnrestricted ())
 496                                 state = PermissionState.Unrestricted;
 497
 498                         PermissionSet interSet = null;
 499 #if NET_2_0
 500                         // much simpler with 2.0
 501                         if (state == PermissionState.Unrestricted) {
 502                                 interSet = new PermissionSet (state);
 503                         } else if (this.IsUnrestricted ()) {
 504                                 interSet = other.Copy ();
 505                         } else if (other.IsUnrestricted ()) {
 506                                 interSet = this.Copy ();
 507                         } else {
 508                                 interSet = new PermissionSet (state);
 509                                 InternalIntersect (interSet, this, other, false);
 510                         }
 511 #else
 512                         interSet = new PermissionSet (state);
 513                         if (state == PermissionState.Unrestricted) {
 514                                 InternalIntersect (interSet, this, other, true);
 515                                 InternalIntersect (interSet, other, this, true);
 516                         } else if (this.IsUnrestricted ()) {
 517                                 InternalIntersect (interSet, this, other, true);
 518                         } else if (other.IsUnrestricted ()) {
 519                                 InternalIntersect (interSet, other, this, true);
 520                         } else {
 521                                 InternalIntersect (interSet, this, other, false);
 522                         }
 523 #endif
 524                         return interSet;
 525                 }
 526
 527                 internal void InternalIntersect (PermissionSet intersect, PermissionSet a, PermissionSet b, bool unrestricted)
 528                 {
 529                         foreach (IPermission p in b.list) {
 530                                 // for every type in both list
 531                                 IPermission i = a.GetPermission (p.GetType ());
 532                                 if (i != null) {
 533                                         // add intersection for this type
 534                                         intersect.AddPermission (p.Intersect (i));
 535                                 }
 536 #if NET_2_0
 537                                 // unrestricted is possible for indentity permissions
 538                                 else if (unrestricted) {
 539 #else
 540                                 else if (unrestricted && (p is IUnrestrictedPermission)) {
 541 #endif
 542                                         intersect.AddPermission (p);
 543                                 }
 544                                 // or reject!
 545                         }
 546                 }
 547
 548                 public virtual bool IsEmpty ()
 549                 {
 550                         // note: Unrestricted isn't empty
 551                         if (state == PermissionState.Unrestricted)
 552                                 return false;
 553                         if ((list == null) || (list.Count == 0))
 554                                 return true;
 555                         // the set may include some empty permissions
 556                         foreach (IPermission p in list) {
 557                                 // empty == fully restricted == IsSubsetOf(null) == true
 558                                 if (!p.IsSubsetOf (null))
 559                                         return false;
 560                         }
 561                         return true;
 562                 }
 563
 564                 public virtual bool IsUnrestricted ()
 565                 {
 566                         return (state == PermissionState.Unrestricted);
 567                 }
 568
 569                 public virtual IPermission RemovePermission (Type permClass)
 570                 {
 571                         if ((permClass == null) || _readOnly)
 572                                 return null;
 573
 574                         foreach (object o in list) {
 575                                 if (o.GetType ().Equals (permClass)) {
 576                                         list.Remove (o);
 577                                         return (IPermission) o;
 578                                 }
 579                         }
 580                         return null;
 581                 }
 582
 583                 public virtual IPermission SetPermission (IPermission perm)
 584                 {
 585                         if ((perm == null) || _readOnly)
 586                                 return perm;
 587 #if NET_2_0
 588                         IUnrestrictedPermission u = (perm as IUnrestrictedPermission);
 589                         if (u == null) {
 590                                 state = PermissionState.None;
 591                         } else {
 592                                 state = u.IsUnrestricted () ? state : PermissionState.None;
 593                         }
 594 #else
 595                         if (perm is IUnrestrictedPermission)
 596                                 state = PermissionState.None;
 597 #endif
 598                         RemovePermission (perm.GetType ());
 599                         list.Add (perm);
 600                         return perm;
 601                 }
 602
 603                 public override string ToString ()
 604                 {
 605                         return ToXml ().ToString ();
 606                 }
 607
 608                 public virtual SecurityElement ToXml ()
 609                 {
 610                         SecurityElement se = new SecurityElement (tagName);
 611                         se.AddAttribute ("class", GetType ().FullName);
 612                         se.AddAttribute ("version", version.ToString ());
 613                         if (state == PermissionState.Unrestricted)
 614                                 se.AddAttribute ("Unrestricted", "true");
 615
 616                         // required for permissions that do not implement IUnrestrictedPermission
 617                         foreach (IPermission p in list) {
 618                                 se.AddChild (p.ToXml ());
 619                         }
 620                         return se;
 621                 }
 622
 623                 public virtual PermissionSet Union (PermissionSet other)
 624                 {
 625                         if (other == null)
 626                                 return this.Copy ();
 627
 628                         PermissionSet copy = null;
 629                         if (this.IsUnrestricted () || other.IsUnrestricted ()) {
 630 #if NET_2_0
 631                                 // there are no child elements in unrestricted permission sets
 632                                 return new PermissionSet (PermissionState.Unrestricted);
 633 #else
 634                                 copy = this.Copy ();
 635                                 // so we keep the "right" type (e.g. NamedPermissionSet)
 636                                 copy.Clear ();
 637                                 copy.state = PermissionState.Unrestricted;
 638                                 // copy all permissions that do not implement IUnrestrictedPermission
 639                                 foreach (IPermission p in this.list) {
 640                                         if (!(p is IUnrestrictedPermission))
 641                                                 copy.AddPermission (p);
 642                                 }
 643                                 foreach (IPermission p in other.list) {
 644                                         if (!(p is IUnrestrictedPermission))
 645                                                 copy.AddPermission (p);
 646                                 }
 647 #endif
 648                         } else {
 649                                 copy = this.Copy ();
 650                                 // PermissionState.None -> copy all permissions
 651                                 foreach (IPermission p in other.list) {
 652                                         copy.AddPermission (p);
 653                                 }
 654                         }
 655                         return copy;
 656                 }
 657
 658                 public virtual int Count {
 659                         get { return list.Count; }
 660                 }
 661
 662                 public virtual bool IsSynchronized {
 663                         get { return list.IsSynchronized; }
 664                 }
 665
 666                 public virtual bool IsReadOnly {
 667                         // always false (as documented) but the PermissionSet can be read-only
 668                         // e.g. in a PolicyStatement
 669                         get { return false; }
 670                 }
 671
 672                 public virtual object SyncRoot {
 673                         get { return this; }
 674                 }
 675
 676                 internal bool DeclarativeSecurity {
 677                         get { return _declsec; }
 678                         set { _declsec = value; }
 679                 }
 680
 681                 [MonoTODO ("may not be required")]
 682                 void IDeserializationCallback.OnDeserialization (object sender)
 683                 {
 684                 }
 685
 686 #if NET_2_0
 687                 [ComVisible (false)]
 688                 public override bool Equals (object obj)
 689                 {
 690                         if (obj == null)
 691                                 return false;
 692                         PermissionSet ps = (obj as PermissionSet);
 693                         if (ps == null)
 694                                 return false;
 695                         if (state != ps.state)
 696                                 return false;
 697                         if (list.Count != ps.Count)
 698                                 return false;
 699
 700                         for (int i=0; i < list.Count; i++) {
 701                                 bool found = false;
 702                                 for (int j=0; i < ps.list.Count; j++) {
 703                                         if (list [i].Equals (ps.list [j])) {
 704                                                 found = true;
 705                                                 break;
 706                                         }
 707                                 }
 708                                 if (!found)
 709                                         return false;
 710                         }
 711                         return true;
 712                 }
 713
 714                 [ComVisible (false)]
 715                 public override int GetHashCode ()
 716                 {
 717                         return (list.Count == 0) ? (int) state : base.GetHashCode ();
 718                 }
 719
 720                 [MonoTODO ("(2.0) what's it doing here? There's probably a reason this was added here.")]
 721                 static public void RevertAssert ()
 722                 {
 723                         CodeAccessPermission.RevertAssert ();
 724                 }
 725 #endif
 726
 727                 // internal
 728
 729                 internal PolicyLevel Resolver {
 730                         get { return _policyLevel; }
 731                         set { _policyLevel = value; }
 732                 }
 733
 734                 internal void SetReadOnly (bool value)
 735                 {
 736                         _readOnly = value;
 737                 }
 738
 739                 private bool AllIgnored ()
 740                 {
 741                         if (_ignored == null)
 742                                 throw new NotSupportedException ("bad bad bad");
 743
 744                         for (int i=0; i < _ignored.Length; i++) {
 745                                 if (!_ignored [i])
 746                                         return false;
 747                         }
 748                         // everything is ignored (i.e. non-CAS permission or asserted permission).
 749                         return true;
 750                 }
 751
 752                 internal bool ProcessFrame (SecurityFrame frame, ref Assembly current, ref AppDomain domain)
 753                 {
 754                         if (IsUnrestricted ()) {
 755                                 // we request unrestricted
 756                                 if (frame.Deny != null) {
 757                                         // but have restrictions (some denied permissions)
 758                                         CodeAccessPermission.ThrowSecurityException (this, "Deny", frame, SecurityAction.Demand, null);
 759                                 } else if ((frame.PermitOnly != null) && !frame.PermitOnly.IsUnrestricted ()) {
 760                                         // but have restrictions (only some permitted permissions)
 761                                         CodeAccessPermission.ThrowSecurityException (this, "PermitOnly", frame, SecurityAction.Demand, null);
 762                                 }
 763                         }
 764
 765                         // skip next steps if no Assert, Deny or PermitOnly are present
 766                         if (frame.HasStackModifiers) {
 767                                 for (int i = 0; i < list.Count; i++) {
 768                                         CodeAccessPermission cap = (CodeAccessPermission) list [i];
 769                                         if (cap.ProcessFrame (frame)) {
 770                                                 _ignored [i] = true; // asserted
 771                                                 if (AllIgnored ())
 772                                                         return true; // no more, abort stack walk!
 773                                         }
 774                                 }
 775                         }
 776
 777                         // however the "final" grant set is resolved by assembly, so
 778                         // there's no need to check it every time (just when we're
 779                         // changing assemblies between frames).
 780                         if (frame.Assembly != current) {
 781                                 CheckAssembly (current, frame);
 782                                 current = frame.Assembly;
 783                         }
 784
 785                         if (frame.Domain != domain) {
 786                                 CheckAppDomain (domain, frame);
 787                                 domain = frame.Domain;
 788                         }
 789
 790                         return false;
 791                 }
 792
 793                 internal void CheckAssembly (Assembly a, SecurityFrame frame)
 794                 {
 795                         IPermission p = SecurityManager.CheckPermissionSet (a, this, false);
 796                         if (p != null) {
 797                                 CodeAccessPermission.ThrowSecurityException (this, "Demand failed assembly permissions checks.",
 798                                         frame, SecurityAction.Demand, p);
 799                         }
 800                 }
 801
 802                 internal void CheckAppDomain (AppDomain domain, SecurityFrame frame)
 803                 {
 804                         IPermission p = SecurityManager.CheckPermissionSet (domain, this);
 805                         if (p != null) {
 806                                 CodeAccessPermission.ThrowSecurityException (this, "Demand failed appdomain permissions checks.",
 807                                         frame, SecurityAction.Demand, p);
 808                         }
 809                 }
 810
 811                 // 2.0 metadata format
 812
 813                 internal static PermissionSet CreateFromBinaryFormat (byte[] data)
 814                 {
 815                         if ((data == null) || (data [0] != 0x2E) || (data.Length < 2)) {
 816                                 string msg = Locale.GetText ("Invalid data in 2.0 metadata format.");
 817                                 throw new SecurityException (msg);
 818                         }
 819
 820                         int pos = 1;
 821                         int numattr = ReadEncodedInt (data, ref pos);
 822                         PermissionSet ps = new PermissionSet (PermissionState.None);
 823                         for (int i = 0; i < numattr; i++) {
 824                                 IPermission p = ProcessAttribute (data, ref pos);
 825                                 if (p == null) {
 826                                         string msg = Locale.GetText ("Unsupported data found in 2.0 metadata format.");
 827                                         throw new SecurityException (msg);
 828                                 }
 829                                 ps.AddPermission (p);
 830                         }
 831                         return ps;
 832                 }
 833
 834                 internal static int ReadEncodedInt (byte[] data, ref int position)
 835                 {
 836                         int len = 0;
 837                         if ((data [position] & 0x80) == 0) {
 838                                 len = data [position];
 839                                 position ++;
 840                         } else if ((data [position] & 0x40) == 0) {
 841                                 len = ((data [position] & 0x3f) << 8 | data [position + 1]);
 842                                 position += 2;
 843                         } else {
 844                                 len = (((data [position] & 0x1f) << 24) | (data [position + 1] << 16) |
 845                                         (data [position + 2] << 8) | (data [position + 3]));
 846                                 position += 4;
 847                         }
 848                         return len;
 849                 }
 850
 851                 static object[] action = new object [1] { (SecurityAction) 0 };
 852
 853                 // TODO: add support for arrays and enums (2.0)
 854                 internal static IPermission ProcessAttribute (byte[] data, ref int position)
 855                 {
 856                         int clen = ReadEncodedInt (data, ref position);
 857                         string cnam = Encoding.UTF8.GetString (data, position, clen);
 858                         position += clen;
 859
 860                         Type secattr = Type.GetType (cnam);
 861                         SecurityAttribute sa = (Activator.CreateInstance (secattr, action) as SecurityAttribute);
 862                         if (sa == null)
 863                                 return null;
 864
 865                         /*int optionalParametersLength =*/ ReadEncodedInt (data, ref position);
 866                         int numberOfParameters = ReadEncodedInt (data, ref position);
 867                         for (int j=0; j < numberOfParameters; j++) {
 868                                 bool property = false;
 869                                 switch (data [position++]) {
 870                                 case 0x53: // field (technically possible and working)
 871                                         property = false;
 872                                         break;
 873                                 case 0x54: // property (common case)
 874                                         property = true;
 875                                         break;
 876                                 default:
 877                                         return null;
 878                                 }
 879
 880                                 bool array = false;
 881                                 byte type = data [position++];
 882                                 if (type == 0x1D) {
 883                                         array = true;
 884                                         type = data [position++];
 885                                 }
 886
 887                                 int plen = ReadEncodedInt (data, ref position);
 888                                 string pnam = Encoding.UTF8.GetString (data, position, plen);
 889                                 position += plen;
 890
 891                                 int arrayLength = 1;
 892                                 if (array) {
 893                                         arrayLength = BitConverter.ToInt32 (data, position);
 894                                         position += 4;
 895                                 }
 896
 897                                 object obj = null;
 898                                 object[] arrayIndex = null;
 899                                 for (int i = 0; i < arrayLength; i++) {
 900                                         if (array) {
 901                                                 // TODO - setup index (2.0)
 902                                         }
 903
 904                                         // sadly type values doesn't match ther TypeCode enum :(
 905                                         switch (type) {
 906                                         case 0x02: // MONO_TYPE_BOOLEAN
 907                                                 obj = (object) Convert.ToBoolean (data [position++]);
 908                                                 break;
 909                                         case 0x03: // MONO_TYPE_CHAR
 910                                                 obj = (object) Convert.ToChar (data [position]);
 911                                                 position += 2;
 912                                                 break;
 913                                         case 0x04: // MONO_TYPE_I1
 914                                                 obj = (object) Convert.ToSByte (data [position++]);
 915                                                 break;
 916                                         case 0x05: // MONO_TYPE_U1
 917                                                 obj = (object) Convert.ToByte (data [position++]);
 918                                                 break;
 919                                         case 0x06: // MONO_TYPE_I2
 920                                                 obj = (object) Convert.ToInt16 (data [position]);
 921                                                 position += 2;
 922                                                 break;
 923                                         case 0x07: // MONO_TYPE_U2
 924                                                 obj = (object) Convert.ToUInt16 (data [position]);
 925                                                 position += 2;
 926                                                 break;
 927                                         case 0x08: // MONO_TYPE_I4
 928                                                 obj = (object) Convert.ToInt32 (data [position]);
 929                                                 position += 4;
 930                                                 break;
 931                                         case 0x09: // MONO_TYPE_U4
 932                                                 obj = (object) Convert.ToUInt32 (data [position]);
 933                                                 position += 4;
 934                                                 break;
 935                                         case 0x0A: // MONO_TYPE_I8
 936                                                 obj = (object) Convert.ToInt64 (data [position]);
 937                                                 position += 8;
 938                                                 break;
 939                                         case 0x0B: // MONO_TYPE_U8
 940                                                 obj = (object) Convert.ToUInt64 (data [position]);
 941                                                 position += 8;
 942                                                 break;
 943                                         case 0x0C: // MONO_TYPE_R4
 944                                                 obj = (object) Convert.ToSingle (data [position]);
 945                                                 position += 4;
 946                                                 break;
 947                                         case 0x0D: // MONO_TYPE_R8
 948                                                 obj = (object) Convert.ToDouble (data [position]);
 949                                                 position += 8;
 950                                                 break;
 951                                         case 0x0E: // MONO_TYPE_STRING
 952                                                 string s = null;
 953                                                 if (data [position] != 0xFF) {
 954                                                         int slen = ReadEncodedInt (data, ref position);
 955                                                         s = Encoding.UTF8.GetString (data, position, slen);
 956                                                         position += slen;
 957                                                 } else {
 958                                                         position++;
 959                                                 }
 960                                                 obj = (object) s;
 961                                                 break;
 962                                         case 0x50: // special for TYPE
 963                                                 int tlen = ReadEncodedInt (data, ref position);
 964                                                 obj = (object) Type.GetType (Encoding.UTF8.GetString (data, position, tlen));
 965                                                 position += tlen;
 966                                                 break;
 967                                         default:
 968                                                 return null; // unsupported
 969                                         }
 970
 971                                         if (property) {
 972                                                 PropertyInfo pi = secattr.GetProperty (pnam);
 973                                                 pi.SetValue (sa, obj, arrayIndex);
 974                                         } else {
 975                                                 FieldInfo fi = secattr.GetField (pnam);
 976                                                 fi.SetValue (sa, obj);
 977                                         }
 978                                 }
 979                         }
 980                         return sa.CreatePermission ();
 981                 }
 982         }
 983 }