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 #if NET_2_0
 120                 public IPermission AddPermission (IPermission perm)
 121 #else
 122                 public virtual IPermission AddPermission (IPermission perm)
 123 #endif
 124                 {
 125                         if ((perm == null) || _readOnly)
 126                                 return perm;
 127
 128                         // we don't add to an unrestricted permission set unless...
 129                         if (state == PermissionState.Unrestricted) {
 130 #if NET_2_0
 131                                 // identity permissions can be unrestricted under 2.x
 132                                 {
 133 #else
 134                                 // we're adding identity permission as they don't support unrestricted
 135                                 if (perm is IUnrestrictedPermission) {
 136 #endif
 137                                         // we return the union of the permission with unrestricted
 138                                         // which results in a permission of the same type initialized
 139                                         // with PermissionState.Unrestricted
 140                                         return (IPermission) Activator.CreateInstance (perm.GetType (), psUnrestricted);
 141                                 }
 142                         }
 143
 144                         // we can't add two permissions of the same type in a set
 145                         // so we remove an existing one, union with it and add it back
 146                         IPermission existing = RemovePermission (perm.GetType ());
 147                         if (existing != null) {
 148                                 perm = perm.Union (existing);
 149                         }
 150
 151                         // note: Add doesn't copy
 152                         list.Add (perm);
 153                         return perm;
 154                 }
 155
 156                 [MonoTODO ("Imperative mode isn't supported")]
 157                 [SecurityPermission (SecurityAction.Demand, Assertion = true)]
 158 #if NET_2_0
 159                 public void Assert ()
 160 #else
 161                 public virtual void Assert ()
 162 #endif
 163                 {
 164                         int count = this.Count;
 165
 166                         // we (current frame) must have the permission to assert it to others
 167                         // otherwise we don't assert (but we don't throw an exception)
 168                         foreach (IPermission p in list) {
 169                                 // note: we ignore non-CAS permissions
 170                                 if (p is IStackWalk) {
 171                                         if (!SecurityManager.IsGranted (p)) {
 172                                                 return;
 173                                         }
 174                                 } else
 175                                         count--;
 176                         }
 177
 178                         // note: we must ignore the stack modifiers for the non-CAS permissions
 179                         if (SecurityManager.SecurityEnabled && (count > 0))
 180                                 throw new NotSupportedException ("Currently only declarative Assert are supported.");
 181                 }
 182
 183                 internal void Clear ()
 184                 {
 185                         list.Clear ();
 186                 }
 187
 188                 public virtual PermissionSet Copy ()
 189                 {
 190                         return new PermissionSet (this);
 191                 }
 192
 193                 public virtual void CopyTo (Array array, int index)
 194                 {
 195                         if (null == array)
 196                                 throw new ArgumentNullException ("array");
 197
 198                         if (list.Count > 0) {
 199                                 if (array.Rank > 1) {
 200                                         throw new ArgumentException (Locale.GetText (
 201                                                 "Array has more than one dimension"));
 202                                 }
 203                                 if (index < 0 || index >= array.Length) {
 204                                         throw new IndexOutOfRangeException ("index");
 205                                 }
 206
 207                                 list.CopyTo (array, index);
 208                         }
 209                 }
 210
 211 #if NET_2_0
 212                 public void Demand ()
 213 #else
 214                 public virtual void Demand ()
 215 #endif
 216                 {
 217                         // Note: SecurityEnabled only applies to CAS permissions
 218                         // so we're not checking for it (yet)
 219                         if (IsEmpty ())
 220                                 return;
 221
 222                         int n = list.Count;
 223                         if ((_ignored == null) || (_ignored.Length != n)) {
 224                                 _ignored = new bool [n];
 225                         }
 226
 227                         bool call_cas_only = this.IsUnrestricted ();
 228                         // non CAS permissions (e.g. PrincipalPermission) do not requires a stack walk
 229                         for (int i = 0; i < n; i++) {
 230                                 CodeAccessPermission p = (CodeAccessPermission) list [i];
 231                                 Type t = p.GetType ();
 232                                 if (t.IsSubclassOf (typeof (CodeAccessPermission))) {
 233                                         _ignored [i] = false;
 234                                         call_cas_only = true;
 235                                 } else {
 236                                         _ignored [i] = true;
 237                                         p.Demand ();
 238                                 }
 239                         }
 240
 241                         // don't start the stack walk if
 242                         // - the permission set only contains non CAS permissions; or
 243                         // - security isn't enabled (applis only to CAS!)
 244                         if (call_cas_only && SecurityManager.SecurityEnabled)
 245                                 CasOnlyDemand (_declsec ? 5 : 3);
 246                 }
 247
 248                 // The number of frames to skip depends on who's calling
 249                 // - CodeAccessPermission.Demand (imperative)
 250                 // - PermissionSet.Demand (imperative)
 251                 // - SecurityManager.InternalDemand (declarative)
 252                 internal void CasOnlyDemand (int skip)
 253                 {
 254                         Assembly current = null;
 255                         AppDomain domain = null;
 256
 257                         if (_ignored == null) {
 258                                 // special case when directly called from CodeAccessPermission.Demand
 259                                 _ignored = new bool [list.Count];
 260                         }
 261
 262                         ArrayList frames = SecurityFrame.GetStack (skip);
 263                         if ((frames != null) && (frames.Count > 0)) {
 264                                 SecurityFrame first = ((SecurityFrame) frames [0]);
 265                                 current = first.Assembly;
 266                                 domain = first.Domain;
 267                                 // skip ourself, Demand and other security runtime methods
 268                                 foreach (SecurityFrame sf in frames) {
 269                                         if (ProcessFrame (sf, ref current, ref domain)) {
 270                                                 if (AllIgnored ())
 271                                                         return; // reached Assert
 272                                         }
 273                                 }
 274                                 SecurityFrame last = ((SecurityFrame) frames [frames.Count - 1]);
 275                                 CheckAssembly (current, last);
 276                                 CheckAppDomain (domain, last);
 277                         }
 278
 279                         // Is there a CompressedStack to handle ?
 280                         CompressedStack stack = Thread.CurrentThread.GetCompressedStack ();
 281                         if ((stack != null) && !stack.IsEmpty ()) {
 282                                 foreach (SecurityFrame frame in stack.List) {
 283                                         if (ProcessFrame (frame, ref current, ref domain)) {
 284                                                 if (AllIgnored ())
 285                                                         return; // reached Assert
 286                                         }
 287                                 }
 288                         }
 289                 }
 290
 291                 [MonoTODO ("Imperative mode isn't supported")]
 292 #if NET_2_0
 293                 public void Deny ()
 294 #else
 295                 public virtual void Deny ()
 296 #endif
 297                 {
 298                         if (!SecurityManager.SecurityEnabled)
 299                                 return;
 300
 301                         foreach (IPermission p in list) {
 302                                 // note: we ignore non-CAS permissions
 303                                 if (p is IStackWalk) {
 304                                         throw new NotSupportedException ("Currently only declarative Deny are supported.");
 305                                 }
 306                         }
 307                 }
 308
 309                 public virtual void FromXml (SecurityElement et)
 310                 {
 311                         if (et == null)
 312                                 throw new ArgumentNullException ("et");
 313                         if (et.Tag != tagName) {
 314                                 string msg = String.Format ("Invalid tag {0} expected {1}", et.Tag, tagName);
 315                                 throw new ArgumentException (msg, "et");
 316                         }
 317
 318                         list.Clear ();
 319
 320                         if (CodeAccessPermission.IsUnrestricted (et)) {
 321                                 state = PermissionState.Unrestricted;
 322 #if NET_2_0
 323                                 // no need to continue for an unrestricted permission
 324                                 // because identity permissions now "supports" unrestricted
 325                                 return;
 326 #endif
 327                         } else {
 328                                 state = PermissionState.None;
 329                         }
 330
 331                         if (et.Children != null) {
 332                                 foreach (SecurityElement se in et.Children) {
 333                                         string className = se.Attribute ("class");
 334                                         if (className == null) {
 335                                                 throw new ArgumentException (Locale.GetText (
 336                                                         "No permission class is specified."));
 337                                         }
 338                                         if (Resolver != null) {
 339                                                 // policy class names do not have to be fully qualified
 340                                                 className = Resolver.ResolveClassName (className);
 341                                         }
 342
 343                                         list.Add (PermissionBuilder.Create (className, se));
 344                                 }
 345                         }
 346                 }
 347
 348 #if NET_2_0
 349                 public IEnumerator GetEnumerator ()
 350 #else
 351                 public virtual IEnumerator GetEnumerator ()
 352 #endif
 353                 {
 354                         return list.GetEnumerator ();
 355                 }
 356
 357                 public virtual bool IsSubsetOf (PermissionSet target)
 358                 {
 359 #if NET_2_0
 360                         // if target is empty we must be empty too
 361                         if ((target == null) || (target.IsEmpty ()))
 362                                 return this.IsEmpty ();
 363
 364                         // all permissions support unrestricted in 2.0
 365                         if (target.IsUnrestricted ())
 366                                 return true;
 367                         if (this.IsUnrestricted ())
 368                                 return false;
 369 #endif
 370                         if (this.IsUnrestricted () && ((target == null) || !target.IsUnrestricted ()))
 371                                 return false;
 372
 373                         // if each of our permission is (a) present and (b) a subset of target
 374                         foreach (IPermission p in list) {
 375 #if !NET_2_0
 376                                 if (target == null) {
 377                                         if (!p.IsSubsetOf (null))
 378                                                 return false;
 379                                 } else
 380 #endif
 381                                 {
 382                                         // non CAS permissions must be evaluated for unrestricted
 383                                         Type t = p.GetType ();
 384                                         IPermission i = null;
 385                                         if (target.IsUnrestricted () && (p is CodeAccessPermission) && (p is IUnrestrictedPermission)) {
 386                                                 i = (IPermission) Activator.CreateInstance (t, psUnrestricted);
 387                                         } else {
 388                                                 i = target.GetPermission (t);
 389                                         }
 390
 391                                         if (!p.IsSubsetOf (i))
 392                                                 return false; // not a subset (condition b)
 393                                 }
 394                         }
 395                         return true;
 396                 }
 397
 398                 [MonoTODO ("Imperative mode isn't supported")]
 399 #if NET_2_0
 400                 public void PermitOnly ()
 401 #else
 402                 public virtual void PermitOnly ()
 403 #endif
 404                 {
 405                         if (!SecurityManager.SecurityEnabled)
 406                                 return;
 407
 408                         foreach (IPermission p in list) {
 409                                 // note: we ignore non-CAS permissions
 410                                 if (p is IStackWalk) {
 411                                         throw new NotSupportedException ("Currently only declarative Deny are supported.");
 412                                 }
 413                         }
 414                 }
 415
 416                 public bool ContainsNonCodeAccessPermissions ()
 417                 {
 418                         if (list.Count > 0) {
 419                                 foreach (IPermission p in list) {
 420                                         if (! p.GetType ().IsSubclassOf (typeof (CodeAccessPermission)))
 421                                                 return true;
 422                                 }
 423                         }
 424                         return false;
 425                 }
 426
 427                 [MonoTODO ("little documentation in Fx 2.0 beta 1")]
 428                 public static byte[] ConvertPermissionSet (string inFormat, byte[] inData, string outFormat)
 429                 {
 430                         if (inFormat == null)
 431                                 throw new ArgumentNullException ("inFormat");
 432                         if (outFormat == null)
 433                                 throw new ArgumentNullException ("outFormat");
 434                         if (inData == null)
 435                                 return null;
 436
 437                         if (inFormat == outFormat)
 438                                 return inData;
 439
 440                         PermissionSet ps = null;
 441
 442                         if (inFormat == "BINARY") {
 443                                 if (outFormat.StartsWith ("XML")) {
 444                                         using (MemoryStream ms = new MemoryStream (inData)) {
 445                                                 BinaryFormatter formatter = new BinaryFormatter ();
 446                                                 ps = (PermissionSet) formatter.Deserialize (ms);
 447                                                 ms.Close ();
 448                                         }
 449                                         string xml = ps.ToString ();
 450                                         switch (outFormat) {
 451                                                 case "XML":
 452                                                 case "XMLASCII":
 453                                                         return Encoding.ASCII.GetBytes (xml);
 454                                                 case "XMLUNICODE":
 455                                                         return Encoding.Unicode.GetBytes (xml);
 456                                         }
 457                                 }
 458                         }
 459                         else if (inFormat.StartsWith ("XML")) {
 460                                 if (outFormat == "BINARY") {
 461                                         string xml = null;
 462                                         switch (inFormat) {
 463                                                 case "XML":
 464                                                 case "XMLASCII":
 465                                                         xml = Encoding.ASCII.GetString (inData);
 466                                                         break;
 467                                                 case "XMLUNICODE":
 468                                                         xml = Encoding.Unicode.GetString (inData);
 469                                                         break;
 470                                         }
 471                                         if (xml != null) {
 472                                                 ps = new PermissionSet (PermissionState.None);
 473                                                 ps.FromXml (SecurityElement.FromString (xml));
 474
 475                                                 MemoryStream ms = new MemoryStream ();
 476                                                 BinaryFormatter formatter = new BinaryFormatter ();
 477                                                 formatter.Serialize (ms, ps);
 478                                                 ms.Close ();
 479                                                 return ms.ToArray ();
 480                                         }
 481                                 }
 482                                 else if (outFormat.StartsWith ("XML")) {
 483                                         string msg = String.Format (Locale.GetText ("Can't convert from {0} to {1}"), inFormat, outFormat);
 484 #if NET_2_0
 485                                         throw new XmlSyntaxException (msg);
 486 #else
 487                                         throw new ArgumentException (msg);
 488 #endif
 489                                 }
 490                         }
 491                         else {
 492                                 // unknown inFormat, returns null
 493                                 return null;
 494                         }
 495                         // unknown outFormat, throw
 496                         throw new SerializationException (String.Format (Locale.GetText ("Unknown output format {0}."), outFormat));
 497                 }
 498
 499 #if NET_2_0
 500                 public IPermission GetPermission (Type permClass)
 501 #else
 502                 public virtual IPermission GetPermission (Type permClass)
 503 #endif
 504                 {
 505                         if ((permClass == null) || (list.Count == 0))
 506                                 return null;
 507
 508                         foreach (object o in list) {
 509                                 if ((o != null) && o.GetType ().Equals (permClass))
 510                                         return (IPermission) o;
 511                         }
 512                         // it's normal to return null for unrestricted sets
 513                         return null;
 514                 }
 515
 516 #if NET_2_0
 517                 public PermissionSet Intersect (PermissionSet other)
 518 #else
 519                 public virtual PermissionSet Intersect (PermissionSet other)
 520 #endif
 521                 {
 522                         // no intersection possible
 523                         if ((other == null) || (other.IsEmpty ()) || (this.IsEmpty ()))
 524                                 return null;
 525
 526                         PermissionState state = PermissionState.None;
 527                         if (this.IsUnrestricted () && other.IsUnrestricted ())
 528                                 state = PermissionState.Unrestricted;
 529
 530                         PermissionSet interSet = null;
 531 #if NET_2_0
 532                         // much simpler with 2.0
 533                         if (state == PermissionState.Unrestricted) {
 534                                 interSet = new PermissionSet (state);
 535                         } else if (this.IsUnrestricted ()) {
 536                                 interSet = other.Copy ();
 537                         } else if (other.IsUnrestricted ()) {
 538                                 interSet = this.Copy ();
 539                         } else {
 540                                 interSet = new PermissionSet (state);
 541                                 InternalIntersect (interSet, this, other, false);
 542                         }
 543 #else
 544                         interSet = new PermissionSet (state);
 545                         if (state == PermissionState.Unrestricted) {
 546                                 InternalIntersect (interSet, this, other, true);
 547                                 InternalIntersect (interSet, other, this, true);
 548                         } else if (this.IsUnrestricted ()) {
 549                                 InternalIntersect (interSet, this, other, true);
 550                         } else if (other.IsUnrestricted ()) {
 551                                 InternalIntersect (interSet, other, this, true);
 552                         } else {
 553                                 InternalIntersect (interSet, this, other, false);
 554                         }
 555 #endif
 556                         return interSet;
 557                 }
 558
 559                 internal void InternalIntersect (PermissionSet intersect, PermissionSet a, PermissionSet b, bool unrestricted)
 560                 {
 561                         foreach (IPermission p in b.list) {
 562                                 // for every type in both list
 563                                 IPermission i = a.GetPermission (p.GetType ());
 564                                 if (i != null) {
 565                                         // add intersection for this type
 566                                         intersect.AddPermission (p.Intersect (i));
 567                                 }
 568 #if NET_2_0
 569                                 // unrestricted is possible for indentity permissions
 570                                 else if (unrestricted) {
 571 #else
 572                                 else if (unrestricted && (p is IUnrestrictedPermission)) {
 573 #endif
 574                                         intersect.AddPermission (p);
 575                                 }
 576                                 // or reject!
 577                         }
 578                 }
 579
 580 #if NET_2_0
 581                 public bool IsEmpty ()
 582 #else
 583                 public virtual bool IsEmpty ()
 584 #endif
 585                 {
 586                         // note: Unrestricted isn't empty
 587                         if (state == PermissionState.Unrestricted)
 588                                 return false;
 589                         if ((list == null) || (list.Count == 0))
 590                                 return true;
 591                         // the set may include some empty permissions
 592                         foreach (IPermission p in list) {
 593                                 // empty == fully restricted == IsSubsetOf(null) == true
 594                                 if (!p.IsSubsetOf (null))
 595                                         return false;
 596                         }
 597                         return true;
 598                 }
 599
 600 #if NET_2_0
 601                 public bool IsUnrestricted ()
 602 #else
 603                 public virtual bool IsUnrestricted ()
 604 #endif
 605                 {
 606                         return (state == PermissionState.Unrestricted);
 607                 }
 608
 609 #if NET_2_0
 610                 public IPermission RemovePermission (Type permClass)
 611 #else
 612                 public virtual IPermission RemovePermission (Type permClass)
 613 #endif
 614                 {
 615                         if ((permClass == null) || _readOnly)
 616                                 return null;
 617
 618                         foreach (object o in list) {
 619                                 if (o.GetType ().Equals (permClass)) {
 620                                         list.Remove (o);
 621                                         return (IPermission) o;
 622                                 }
 623                         }
 624                         return null;
 625                 }
 626
 627 #if NET_2_0
 628                 public IPermission SetPermission (IPermission perm)
 629 #else
 630                 public virtual IPermission SetPermission (IPermission perm)
 631 #endif
 632                 {
 633                         if ((perm == null) || _readOnly)
 634                                 return perm;
 635 #if NET_2_0
 636                         IUnrestrictedPermission u = (perm as IUnrestrictedPermission);
 637                         if (u == null) {
 638                                 state = PermissionState.None;
 639                         } else {
 640                                 state = u.IsUnrestricted () ? state : PermissionState.None;
 641                         }
 642 #else
 643                         if (perm is IUnrestrictedPermission)
 644                                 state = PermissionState.None;
 645 #endif
 646                         RemovePermission (perm.GetType ());
 647                         list.Add (perm);
 648                         return perm;
 649                 }
 650
 651                 public override string ToString ()
 652                 {
 653                         return ToXml ().ToString ();
 654                 }
 655
 656                 public virtual SecurityElement ToXml ()
 657                 {
 658                         SecurityElement se = new SecurityElement (tagName);
 659                         se.AddAttribute ("class", GetType ().FullName);
 660                         se.AddAttribute ("version", version.ToString ());
 661                         if (state == PermissionState.Unrestricted)
 662                                 se.AddAttribute ("Unrestricted", "true");
 663
 664                         // required for permissions that do not implement IUnrestrictedPermission
 665                         foreach (IPermission p in list) {
 666                                 se.AddChild (p.ToXml ());
 667                         }
 668                         return se;
 669                 }
 670
 671 #if NET_2_0
 672                 public PermissionSet Union (PermissionSet other)
 673 #else
 674                 public virtual PermissionSet Union (PermissionSet other)
 675 #endif
 676                 {
 677                         if (other == null)
 678                                 return this.Copy ();
 679
 680                         PermissionSet copy = null;
 681                         if (this.IsUnrestricted () || other.IsUnrestricted ()) {
 682 #if NET_2_0
 683                                 // there are no child elements in unrestricted permission sets
 684                                 return new PermissionSet (PermissionState.Unrestricted);
 685 #else
 686                                 copy = this.Copy ();
 687                                 // so we keep the "right" type (e.g. NamedPermissionSet)
 688                                 copy.Clear ();
 689                                 copy.state = PermissionState.Unrestricted;
 690                                 // copy all permissions that do not implement IUnrestrictedPermission
 691                                 foreach (IPermission p in this.list) {
 692                                         if (!(p is IUnrestrictedPermission))
 693                                                 copy.AddPermission (p);
 694                                 }
 695                                 foreach (IPermission p in other.list) {
 696                                         if (!(p is IUnrestrictedPermission))
 697                                                 copy.AddPermission (p);
 698                                 }
 699 #endif
 700                         } else {
 701                                 copy = this.Copy ();
 702                                 // PermissionState.None -> copy all permissions
 703                                 foreach (IPermission p in other.list) {
 704                                         copy.AddPermission (p);
 705                                 }
 706                         }
 707                         return copy;
 708                 }
 709
 710                 public virtual int Count {
 711                         get { return list.Count; }
 712                 }
 713
 714                 public virtual bool IsSynchronized {
 715                         get { return list.IsSynchronized; }
 716                 }
 717
 718                 public virtual bool IsReadOnly {
 719                         // always false (as documented) but the PermissionSet can be read-only
 720                         // e.g. in a PolicyStatement
 721                         get { return false; }
 722                 }
 723
 724                 public virtual object SyncRoot {
 725                         get { return this; }
 726                 }
 727
 728                 internal bool DeclarativeSecurity {
 729                         get { return _declsec; }
 730                         set { _declsec = value; }
 731                 }
 732
 733                 [MonoTODO ("may not be required")]
 734                 void IDeserializationCallback.OnDeserialization (object sender)
 735                 {
 736                 }
 737
 738 #if NET_2_0
 739                 [ComVisible (false)]
 740                 public override bool Equals (object obj)
 741                 {
 742                         if (obj == null)
 743                                 return false;
 744                         PermissionSet ps = (obj as PermissionSet);
 745                         if (ps == null)
 746                                 return false;
 747                         if (state != ps.state)
 748                                 return false;
 749                         if (list.Count != ps.Count)
 750                                 return false;
 751
 752                         for (int i=0; i < list.Count; i++) {
 753                                 bool found = false;
 754                                 for (int j=0; i < ps.list.Count; j++) {
 755                                         if (list [i].Equals (ps.list [j])) {
 756                                                 found = true;
 757                                                 break;
 758                                         }
 759                                 }
 760                                 if (!found)
 761                                         return false;
 762                         }
 763                         return true;
 764                 }
 765
 766                 [ComVisible (false)]
 767                 public override int GetHashCode ()
 768                 {
 769                         return (list.Count == 0) ? (int) state : base.GetHashCode ();
 770                 }
 771
 772                 [MonoTODO ("(2.0) what's it doing here? There's probably a reason this was added here.")]
 773                 static public void RevertAssert ()
 774                 {
 775                         CodeAccessPermission.RevertAssert ();
 776                 }
 777 #endif
 778
 779                 // internal
 780
 781                 internal PolicyLevel Resolver {
 782                         get { return _policyLevel; }
 783                         set { _policyLevel = value; }
 784                 }
 785
 786                 internal void SetReadOnly (bool value)
 787                 {
 788                         _readOnly = value;
 789                 }
 790
 791                 private bool AllIgnored ()
 792                 {
 793                         if (_ignored == null)
 794                                 throw new NotSupportedException ("bad bad bad");
 795
 796                         for (int i=0; i < _ignored.Length; i++) {
 797                                 if (!_ignored [i])
 798                                         return false;
 799                         }
 800                         // everything is ignored (i.e. non-CAS permission or asserted permission).
 801                         return true;
 802                 }
 803
 804                 internal bool ProcessFrame (SecurityFrame frame, ref Assembly current, ref AppDomain domain)
 805                 {
 806                         if (IsUnrestricted ()) {
 807                                 // we request unrestricted
 808                                 if (frame.Deny != null) {
 809                                         // but have restrictions (some denied permissions)
 810                                         CodeAccessPermission.ThrowSecurityException (this, "Deny", frame, SecurityAction.Demand, null);
 811                                 } else if ((frame.PermitOnly != null) && !frame.PermitOnly.IsUnrestricted ()) {
 812                                         // but have restrictions (only some permitted permissions)
 813                                         CodeAccessPermission.ThrowSecurityException (this, "PermitOnly", frame, SecurityAction.Demand, null);
 814                                 }
 815                         }
 816
 817                         // skip next steps if no Assert, Deny or PermitOnly are present
 818                         if (frame.HasStackModifiers) {
 819                                 for (int i = 0; i < list.Count; i++) {
 820                                         CodeAccessPermission cap = (CodeAccessPermission) list [i];
 821                                         if (cap.ProcessFrame (frame)) {
 822                                                 _ignored [i] = true; // asserted
 823                                                 if (AllIgnored ())
 824                                                         return true; // no more, abort stack walk!
 825                                         }
 826                                 }
 827                         }
 828
 829                         // however the "final" grant set is resolved by assembly, so
 830                         // there's no need to check it every time (just when we're
 831                         // changing assemblies between frames).
 832                         if (frame.Assembly != current) {
 833                                 CheckAssembly (current, frame);
 834                                 current = frame.Assembly;
 835                         }
 836
 837                         if (frame.Domain != domain) {
 838                                 CheckAppDomain (domain, frame);
 839                                 domain = frame.Domain;
 840                         }
 841
 842                         return false;
 843                 }
 844
 845                 internal void CheckAssembly (Assembly a, SecurityFrame frame)
 846                 {
 847                         IPermission p = SecurityManager.CheckPermissionSet (a, this, false);
 848                         if (p != null) {
 849                                 CodeAccessPermission.ThrowSecurityException (this, "Demand failed assembly permissions checks.",
 850                                         frame, SecurityAction.Demand, p);
 851                         }
 852                 }
 853
 854                 internal void CheckAppDomain (AppDomain domain, SecurityFrame frame)
 855                 {
 856                         IPermission p = SecurityManager.CheckPermissionSet (domain, this);
 857                         if (p != null) {
 858                                 CodeAccessPermission.ThrowSecurityException (this, "Demand failed appdomain permissions checks.",
 859                                         frame, SecurityAction.Demand, p);
 860                         }
 861                 }
 862
 863                 // 2.0 metadata format
 864
 865                 internal static PermissionSet CreateFromBinaryFormat (byte[] data)
 866                 {
 867                         if ((data == null) || (data [0] != 0x2E) || (data.Length < 2)) {
 868                                 string msg = Locale.GetText ("Invalid data in 2.0 metadata format.");
 869                                 throw new SecurityException (msg);
 870                         }
 871
 872                         int pos = 1;
 873                         int numattr = ReadEncodedInt (data, ref pos);
 874                         PermissionSet ps = new PermissionSet (PermissionState.None);
 875                         for (int i = 0; i < numattr; i++) {
 876                                 IPermission p = ProcessAttribute (data, ref pos);
 877                                 if (p == null) {
 878                                         string msg = Locale.GetText ("Unsupported data found in 2.0 metadata format.");
 879                                         throw new SecurityException (msg);
 880                                 }
 881                                 ps.AddPermission (p);
 882                         }
 883                         return ps;
 884                 }
 885
 886                 internal static int ReadEncodedInt (byte[] data, ref int position)
 887                 {
 888                         int len = 0;
 889                         if ((data [position] & 0x80) == 0) {
 890                                 len = data [position];
 891                                 position ++;
 892                         } else if ((data [position] & 0x40) == 0) {
 893                                 len = ((data [position] & 0x3f) << 8 | data [position + 1]);
 894                                 position += 2;
 895                         } else {
 896                                 len = (((data [position] & 0x1f) << 24) | (data [position + 1] << 16) |
 897                                         (data [position + 2] << 8) | (data [position + 3]));
 898                                 position += 4;
 899                         }
 900                         return len;
 901                 }
 902
 903                 static object[] action = new object [1] { (SecurityAction) 0 };
 904
 905                 // TODO: add support for arrays and enums (2.0)
 906                 internal static IPermission ProcessAttribute (byte[] data, ref int position)
 907                 {
 908                         int clen = ReadEncodedInt (data, ref position);
 909                         string cnam = Encoding.UTF8.GetString (data, position, clen);
 910                         position += clen;
 911
 912                         Type secattr = Type.GetType (cnam);
 913                         SecurityAttribute sa = (Activator.CreateInstance (secattr, action) as SecurityAttribute);
 914                         if (sa == null)
 915                                 return null;
 916
 917                         /*int optionalParametersLength =*/ ReadEncodedInt (data, ref position);
 918                         int numberOfParameters = ReadEncodedInt (data, ref position);
 919                         for (int j=0; j < numberOfParameters; j++) {
 920                                 bool property = false;
 921                                 switch (data [position++]) {
 922                                 case 0x53: // field (technically possible and working)
 923                                         property = false;
 924                                         break;
 925                                 case 0x54: // property (common case)
 926                                         property = true;
 927                                         break;
 928                                 default:
 929                                         return null;
 930                                 }
 931
 932                                 bool array = false;
 933                                 byte type = data [position++];
 934                                 if (type == 0x1D) {
 935                                         array = true;
 936                                         type = data [position++];
 937                                 }
 938
 939                                 int plen = ReadEncodedInt (data, ref position);
 940                                 string pnam = Encoding.UTF8.GetString (data, position, plen);
 941                                 position += plen;
 942
 943                                 int arrayLength = 1;
 944                                 if (array) {
 945                                         arrayLength = BitConverter.ToInt32 (data, position);
 946                                         position += 4;
 947                                 }
 948
 949                                 object obj = null;
 950                                 object[] arrayIndex = null;
 951                                 for (int i = 0; i < arrayLength; i++) {
 952                                         if (array) {
 953                                                 // TODO - setup index (2.0)
 954                                         }
 955
 956                                         // sadly type values doesn't match ther TypeCode enum :(
 957                                         switch (type) {
 958                                         case 0x02: // MONO_TYPE_BOOLEAN
 959                                                 obj = (object) Convert.ToBoolean (data [position++]);
 960                                                 break;
 961                                         case 0x03: // MONO_TYPE_CHAR
 962                                                 obj = (object) Convert.ToChar (data [position]);
 963                                                 position += 2;
 964                                                 break;
 965                                         case 0x04: // MONO_TYPE_I1
 966                                                 obj = (object) Convert.ToSByte (data [position++]);
 967                                                 break;
 968                                         case 0x05: // MONO_TYPE_U1
 969                                                 obj = (object) Convert.ToByte (data [position++]);
 970                                                 break;
 971                                         case 0x06: // MONO_TYPE_I2
 972                                                 obj = (object) Convert.ToInt16 (data [position]);
 973                                                 position += 2;
 974                                                 break;
 975                                         case 0x07: // MONO_TYPE_U2
 976                                                 obj = (object) Convert.ToUInt16 (data [position]);
 977                                                 position += 2;
 978                                                 break;
 979                                         case 0x08: // MONO_TYPE_I4
 980                                                 obj = (object) Convert.ToInt32 (data [position]);
 981                                                 position += 4;
 982                                                 break;
 983                                         case 0x09: // MONO_TYPE_U4
 984                                                 obj = (object) Convert.ToUInt32 (data [position]);
 985                                                 position += 4;
 986                                                 break;
 987                                         case 0x0A: // MONO_TYPE_I8
 988                                                 obj = (object) Convert.ToInt64 (data [position]);
 989                                                 position += 8;
 990                                                 break;
 991                                         case 0x0B: // MONO_TYPE_U8
 992                                                 obj = (object) Convert.ToUInt64 (data [position]);
 993                                                 position += 8;
 994                                                 break;
 995                                         case 0x0C: // MONO_TYPE_R4
 996                                                 obj = (object) Convert.ToSingle (data [position]);
 997                                                 position += 4;
 998                                                 break;
 999                                         case 0x0D: // MONO_TYPE_R8
1000                                                 obj = (object) Convert.ToDouble (data [position]);
1001                                                 position += 8;
1002                                                 break;
1003                                         case 0x0E: // MONO_TYPE_STRING
1004                                                 string s = null;
1005                                                 if (data [position] != 0xFF) {
1006                                                         int slen = ReadEncodedInt (data, ref position);
1007                                                         s = Encoding.UTF8.GetString (data, position, slen);
1008                                                         position += slen;
1009                                                 } else {
1010                                                         position++;
1011                                                 }
1012                                                 obj = (object) s;
1013                                                 break;
1014                                         case 0x50: // special for TYPE
1015                                                 int tlen = ReadEncodedInt (data, ref position);
1016                                                 obj = (object) Type.GetType (Encoding.UTF8.GetString (data, position, tlen));
1017                                                 position += tlen;
1018                                                 break;
1019                                         default:
1020                                                 return null; // unsupported
1021                                         }
1022
1023                                         if (property) {
1024                                                 PropertyInfo pi = secattr.GetProperty (pnam);
1025                                                 pi.SetValue (sa, obj, arrayIndex);
1026                                         } else {
1027                                                 FieldInfo fi = secattr.GetField (pnam);
1028                                                 fi.SetValue (sa, obj);
1029                                         }
1030                                 }
1031                         }
1032                         return sa.CreatePermission ();
1033                 }
1034         }
1035 }