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