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         public class PermissionSet: ISecurityEncodable, ICollection, IEnumerable, IStackWalk, IDeserializationCallback {
  50
  51                 private static string tagName = "PermissionSet";
  52                 private const int version = 1;
  53                 private static object[] psNone = new object [1] { PermissionState.None };
  54
  55                 private PermissionState state;
  56                 private ArrayList list;
  57                 private int _hashcode;
  58                 private PolicyLevel _policyLevel;
  59                 private bool _declsec;
  60
  61                 // constructors
  62
  63                 // for PolicyLevel (to avoid validation duplication)
  64                 internal PermissionSet ()
  65                 {
  66                         list = new ArrayList ();
  67                 }
  68
  69                 public PermissionSet (PermissionState state) : this ()
  70                 {
  71                         if (!Enum.IsDefined (typeof (PermissionState), state))
  72                                 throw new System.ArgumentException ("state");
  73                         this.state = state;
  74                 }
  75
  76                 public PermissionSet (PermissionSet permSet) : this ()
  77                 {
  78                         // LAMESPEC: This would be handled by the compiler.  No way permSet is not a PermissionSet.
  79                         //if (!(permSet is PermissionSet))
  80                         //      throw new System.ArgumentException(); // permSet is not an instance of System.Security.PermissionSet.
  81                         if (permSet == null)
  82                                 state = PermissionState.Unrestricted;
  83                         else {
  84                                 state = permSet.state;
  85                                 foreach (IPermission p in permSet.list)
  86                                         list.Add (p);
  87                         }
  88                 }
  89
  90                 internal PermissionSet (string xml)
  91                         : this ()
  92                 {
  93                         state = PermissionState.None;
  94                         if (xml != null) {
  95                                 SecurityElement se = SecurityElement.FromString (xml);
  96                                 FromXml (se);
  97                         }
  98                 }
  99
 100                 // Light version for creating a (non unrestricted) PermissionSet with
 101                 // a single permission. This allows to relax most validations.
 102                 internal PermissionSet (IPermission perm)
 103                         : this ()
 104                 {
 105                         if (perm != null) {
 106                                 // note: we do not copy IPermission like AddPermission
 107                                 list.Add (perm);
 108                         }
 109                 }
 110
 111                 // methods
 112
 113                 public virtual IPermission AddPermission (IPermission perm)
 114                 {
 115                         if (perm == null)
 116                                 return null;
 117
 118                         // we don't add to an unrestricted permission set unless...
 119                         if (state == PermissionState.Unrestricted) {
 120                                 // we're adding identity permission as they don't support unrestricted
 121                                 if (perm is IUnrestrictedPermission) {
 122                                         // we return the union of the permission with unrestricted
 123                                         // which results in a permission of the same type initialized
 124                                         // with PermissionState.Unrestricted
 125                                         object[] args = new object [1] { PermissionState.Unrestricted };
 126                                         return (IPermission) Activator.CreateInstance (perm.GetType (), args);
 127                                 }
 128                         }
 129
 130                         // we can't add two permissions of the same type in a set
 131                         // so we remove an existing one, union with it and add it back
 132                         IPermission existing = RemovePermission (perm.GetType ());
 133                         if (existing != null) {
 134                                 perm = perm.Union (existing);
 135                         }
 136
 137                         // note: Add doesn't copy
 138                         list.Add (perm);
 139                         return perm;
 140                 }
 141
 142                 [MonoTODO ("Imperative mode isn't supported")]
 143                 public virtual void Assert ()
 144                 {
 145                         new SecurityPermission (SecurityPermissionFlag.Assertion).Demand ();
 146
 147                         int count = this.Count;
 148
 149                         // we (current frame) must have the permission to assert it to others
 150                         // otherwise we don't assert (but we don't throw an exception)
 151                         foreach (IPermission p in list) {
 152                                 // note: we ignore non-CAS permissions
 153                                 if (p is IStackWalk) {
 154                                         if (!SecurityManager.IsGranted (p)) {
 155                                                 return;
 156                                         }
 157                                 } else
 158                                         count--;
 159                         }
 160
 161                         // note: we must ignore the stack modifiers for the non-CAS permissions
 162                         if (SecurityManager.SecurityEnabled && (count > 0))
 163                                 throw new NotSupportedException ("Currently only declarative Assert are supported.");
 164                 }
 165
 166                 internal void Clear ()
 167                 {
 168                         list.Clear ();
 169                 }
 170
 171                 public virtual PermissionSet Copy ()
 172                 {
 173                         return new PermissionSet (this);
 174                 }
 175
 176                 public virtual void CopyTo (Array array, int index)
 177                 {
 178                         if (null == array)
 179                                 throw new ArgumentNullException ("array");
 180
 181                         if (list.Count > 0) {
 182                                 if (array.Rank > 1) {
 183                                         throw new ArgumentException (Locale.GetText (
 184                                                 "Array has more than one dimension"));
 185                                 }
 186                                 if (index < 0 || index >= array.Length) {
 187                                         throw new IndexOutOfRangeException ("index");
 188                                 }
 189
 190                                 list.CopyTo (array, index);
 191                         }
 192                 }
 193
 194                 [MonoTODO ("Imperative Assert, Deny and PermitOnly aren't yet supported")]
 195                 public virtual void Demand ()
 196                 {
 197                         // Note: SecurityEnabled only applies to CAS permissions
 198                         // so we're not checking for it (yet)
 199                         if (IsEmpty ())
 200                                 return;
 201
 202                         PermissionSet cas = this;
 203                         // avoid copy (if possible)
 204                         if (ContainsNonCodeAccessPermissions ()) {
 205                                 // non CAS permissions (e.g. PrincipalPermission) do not requires a stack walk
 206                                 cas = this.Copy ();
 207                                 foreach (IPermission p in list) {
 208                                         Type t = p.GetType ();
 209                                         if (!t.IsSubclassOf (typeof (CodeAccessPermission))) {
 210                                                 p.Demand ();
 211                                                 // we wont have to process this one in the stack walk
 212                                                 cas.RemovePermission (t);
 213                                         }
 214                                 }
 215                         }
 216
 217                         // don't start the stack walk if
 218                         // - the permission set only contains non CAS permissions; or
 219                         // - security isn't enabled (applis only to CAS!)
 220                         if (!cas.IsEmpty () && SecurityManager.SecurityEnabled)
 221                                 CasOnlyDemand (_declsec ? 5 : 3);
 222                 }
 223
 224                 // The number of frames to skip depends on who's calling
 225                 // - CodeAccessPermission.Demand (imperative)
 226                 // - PermissionSet.Demand (imperative)
 227                 // - SecurityManager.InternalDemand (declarative)
 228                 internal void CasOnlyDemand (int skip)
 229                 {
 230                         Assembly current = null;
 231                         AppDomain domain = null;
 232
 233                         ArrayList frames = SecurityFrame.GetStack (skip);
 234                         if ((frames != null) && (frames.Count > 0)) {
 235                                 SecurityFrame first = ((SecurityFrame) frames [0]);
 236                                 current = first.Assembly;
 237                                 domain = first.Domain;
 238                                 // skip ourself, Demand and other security runtime methods
 239                                 foreach (SecurityFrame sf in frames) {
 240                                         if (ProcessFrame (sf, ref current, ref domain))
 241                                                 return; // reached Assert
 242                                 }
 243                                 SecurityFrame last = ((SecurityFrame) frames [frames.Count - 1]);
 244                                 CheckAssembly (current, last);
 245                                 CheckAppDomain (domain, last);
 246                         }
 247
 248                         // Is there a CompressedStack to handle ?
 249                         CompressedStack stack = Thread.CurrentThread.GetCompressedStack ();
 250                         if ((stack != null) && !stack.IsEmpty ()) {
 251                                 foreach (SecurityFrame frame in stack.List) {
 252                                         if (ProcessFrame (frame, ref current, ref domain))
 253                                                 return; // reached Assert
 254                                 }
 255                         }
 256                 }
 257
 258                 [MonoTODO ("Imperative mode isn't supported")]
 259                 public virtual void Deny ()
 260                 {
 261                         if (!SecurityManager.SecurityEnabled)
 262                                 return;
 263
 264                         foreach (IPermission p in list) {
 265                                 // note: we ignore non-CAS permissions
 266                                 if (p is IStackWalk) {
 267                                         throw new NotSupportedException ("Currently only declarative Deny are supported.");
 268                                 }
 269                         }
 270                 }
 271
 272                 [MonoTODO ("adjust class version with current runtime - unification")]
 273                 public virtual void FromXml (SecurityElement et)
 274                 {
 275                         if (et == null)
 276                                 throw new ArgumentNullException ("et");
 277                         if (et.Tag != tagName) {
 278                                 string msg = String.Format ("Invalid tag {0} expected {1}", et.Tag, tagName);
 279                                 throw new ArgumentException (msg, "et");
 280                         }
 281
 282                         if (CodeAccessPermission.IsUnrestricted (et))
 283                                 state = PermissionState.Unrestricted;
 284                         else
 285                                 state = PermissionState.None;
 286
 287                         list.Clear ();
 288                         if (et.Children != null) {
 289                                 foreach (SecurityElement se in et.Children) {
 290                                         string className = se.Attribute ("class");
 291                                         if (className == null) {
 292                                                 throw new ArgumentException (Locale.GetText (
 293                                                         "No permission class is specified."));
 294                                         }
 295                                         if (Resolver != null) {
 296                                                 // policy class names do not have to be fully qualified
 297                                                 className = Resolver.ResolveClassName (className);
 298                                         }
 299                                         // TODO: adjust class version with current runtime (unification)
 300                                         // http://blogs.msdn.com/shawnfa/archive/2004/08/05/209320.aspx
 301                                         Type classType = Type.GetType (className);
 302                                         if (classType != null) {
 303                                                 IPermission p = (IPermission) Activator.CreateInstance (classType, psNone);
 304                                                 p.FromXml (se);
 305                                                 list.Add (p);
 306                                         }
 307 #if !NET_2_0
 308                                         else {
 309                                                 string msg = Locale.GetText ("Can't create an instance of permission class {0}.");
 310                                                 throw new ArgumentException (String.Format (msg, se.Attribute ("class")));
 311                                         }
 312 #endif
 313                                 }
 314                         }
 315                 }
 316
 317                 public virtual IEnumerator GetEnumerator ()
 318                 {
 319                         return list.GetEnumerator ();
 320                 }
 321
 322                 public virtual bool IsSubsetOf (PermissionSet target)
 323                 {
 324                         // if target is empty we must be empty too
 325                         if ((target == null) || (target.IsEmpty ()))
 326                                 return this.IsEmpty ();
 327
 328                         // TODO - non CAS permissions must be evaluated for unrestricted
 329
 330                         // if target is unrestricted then we are a subset
 331                         if (!this.IsUnrestricted () && target.IsUnrestricted ())
 332                                 return true;
 333                         // else target isn't unrestricted.
 334                         // so if we are unrestricted, the we can't be a subset
 335                         if (this.IsUnrestricted () && !target.IsUnrestricted ())
 336                                 return false;
 337
 338                         // if each of our permission is (a) present and (b) a subset of target
 339                         foreach (IPermission p in list) {
 340                                 // for every type in both list
 341                                 IPermission i = target.GetPermission (p.GetType ());
 342                                 if (i == null)
 343                                         return false; // not present (condition a)
 344                                 if (!p.IsSubsetOf (i))
 345                                         return false; // not a subset (condition b)
 346                         }
 347                         return true;
 348                 }
 349
 350                 [MonoTODO ("Imperative mode isn't supported")]
 351                 public virtual void PermitOnly ()
 352                 {
 353                         if (!SecurityManager.SecurityEnabled)
 354                                 return;
 355
 356                         foreach (IPermission p in list) {
 357                                 // note: we ignore non-CAS permissions
 358                                 if (p is IStackWalk) {
 359                                         throw new NotSupportedException ("Currently only declarative Deny are supported.");
 360                                 }
 361                         }
 362                 }
 363
 364                 public bool ContainsNonCodeAccessPermissions ()
 365                 {
 366                         foreach (IPermission p in list) {
 367                                 if (! p.GetType ().IsSubclassOf (typeof (CodeAccessPermission)))
 368                                         return true;
 369                         }
 370                         return false;
 371                 }
 372
 373                 [MonoTODO ("little documentation in Fx 2.0 beta 1")]
 374                 public static byte[] ConvertPermissionSet (string inFormat, byte[] inData, string outFormat)
 375                 {
 376                         if (inFormat == null)
 377                                 throw new ArgumentNullException ("inFormat");
 378                         if (outFormat == null)
 379                                 throw new ArgumentNullException ("outFormat");
 380                         if (inData == null)
 381                                 return null;
 382
 383                         if (inFormat == outFormat)
 384                                 return inData;
 385
 386                         PermissionSet ps = null;
 387
 388                         if (inFormat == "BINARY") {
 389                                 if (outFormat.StartsWith ("XML")) {
 390                                         using (MemoryStream ms = new MemoryStream (inData)) {
 391                                                 BinaryFormatter formatter = new BinaryFormatter ();
 392                                                 ps = (PermissionSet) formatter.Deserialize (ms);
 393                                                 ms.Close ();
 394                                         }
 395                                         string xml = ps.ToString ();
 396                                         switch (outFormat) {
 397                                                 case "XML":
 398                                                 case "XMLASCII":
 399                                                         return Encoding.ASCII.GetBytes (xml);
 400                                                 case "XMLUNICODE":
 401                                                         return Encoding.Unicode.GetBytes (xml);
 402                                         }
 403                                 }
 404                         }
 405                         else if (inFormat.StartsWith ("XML")) {
 406                                 if (outFormat == "BINARY") {
 407                                         string xml = null;
 408                                         switch (inFormat) {
 409                                                 case "XML":
 410                                                 case "XMLASCII":
 411                                                         xml = Encoding.ASCII.GetString (inData);
 412                                                         break;
 413                                                 case "XMLUNICODE":
 414                                                         xml = Encoding.Unicode.GetString (inData);
 415                                                         break;
 416                                         }
 417                                         if (xml != null) {
 418                                                 ps = new PermissionSet (PermissionState.None);
 419                                                 ps.FromXml (SecurityElement.FromString (xml));
 420
 421                                                 MemoryStream ms = new MemoryStream ();
 422                                                 BinaryFormatter formatter = new BinaryFormatter ();
 423                                                 formatter.Serialize (ms, ps);
 424                                                 ms.Close ();
 425                                                 return ms.ToArray ();
 426                                         }
 427                                 }
 428                                 else if (outFormat.StartsWith ("XML")) {
 429                                         string msg = String.Format (Locale.GetText ("Can't convert from {0} to {1}"), inFormat, outFormat);
 430 #if NET_2_0
 431                                         throw new XmlSyntaxException (msg);
 432 #else
 433                                         throw new ArgumentException (msg);
 434 #endif
 435                                 }
 436                         }
 437                         else {
 438                                 // unknown inFormat, returns null
 439                                 return null;
 440                         }
 441                         // unknown outFormat, throw
 442                         throw new SerializationException (String.Format (Locale.GetText ("Unknown output format {0}."), outFormat));
 443                 }
 444
 445                 public virtual IPermission GetPermission (Type permClass)
 446                 {
 447                         foreach (object o in list) {
 448                                 if (o.GetType ().Equals (permClass))
 449                                         return (IPermission) o;
 450                         }
 451                         // it's normal to return null for unrestricted sets
 452                         return null;
 453                 }
 454
 455                 public virtual PermissionSet Intersect (PermissionSet other)
 456                 {
 457                         // no intersection possible
 458                         if ((other == null) || (other.IsEmpty ()) || (this.IsEmpty ()))
 459                                 return null;
 460
 461                         PermissionState state = PermissionState.None;
 462                         if (this.IsUnrestricted () && other.IsUnrestricted ())
 463                                 state = PermissionState.Unrestricted;
 464
 465                         PermissionSet interSet = new PermissionSet (state);
 466                         if (state == PermissionState.Unrestricted) {
 467                                 InternalIntersect (interSet, this, other, true);
 468                                 InternalIntersect (interSet, other, this, true);
 469                         }
 470                         else if (this.IsUnrestricted ()) {
 471                                 InternalIntersect (interSet, this, other, true);
 472                         }
 473                         else if (other.IsUnrestricted ()) {
 474                                 InternalIntersect (interSet, other, this, true);
 475                         }
 476                         else {
 477                                 InternalIntersect (interSet, this, other, false);
 478                         }
 479                         return interSet;
 480                 }
 481
 482                 internal void InternalIntersect (PermissionSet intersect, PermissionSet a, PermissionSet b, bool unrestricted)
 483                 {
 484                         foreach (IPermission p in b.list) {
 485                                 // for every type in both list
 486                                 IPermission i = a.GetPermission (p.GetType ());
 487                                 if (i != null) {
 488                                         // add intersection for this type
 489                                         intersect.AddPermission (p.Intersect (i));
 490                                 }
 491                                 else if (unrestricted && (p is IUnrestrictedPermission)) {
 492                                         intersect.AddPermission (p);
 493                                 }
 494                                 // or reject!
 495                         }
 496                 }
 497
 498                 public virtual bool IsEmpty ()
 499                 {
 500                         // note: Unrestricted isn't empty
 501                         if (state == PermissionState.Unrestricted)
 502                                 return false;
 503                         if ((list == null) || (list.Count == 0))
 504                                 return true;
 505                         // the set may include some empty permissions
 506                         foreach (IPermission p in list) {
 507                                 // empty == fully restricted == IsSubsetOg(null) == true
 508                                 if (!p.IsSubsetOf (null))
 509                                         return false;
 510                         }
 511                         return true;
 512                 }
 513
 514                 public virtual bool IsUnrestricted ()
 515                 {
 516                         return (state == PermissionState.Unrestricted);
 517                 }
 518
 519                 public virtual IPermission RemovePermission (Type permClass)
 520                 {
 521                         if (permClass == null)
 522                                 return null;
 523
 524                         foreach (object o in list) {
 525                                 if (o.GetType ().Equals (permClass)) {
 526                                         list.Remove (o);
 527                                         return (IPermission) o;
 528                                 }
 529                         }
 530                         return null;
 531                 }
 532
 533                 public virtual IPermission SetPermission (IPermission perm)
 534                 {
 535                         if (perm == null)
 536                                 return null;
 537                         if (perm is IUnrestrictedPermission)
 538                                 state = PermissionState.None;
 539                         RemovePermission (perm.GetType ());
 540                         list.Add (perm);
 541                         return perm;
 542                 }
 543
 544                 public override string ToString ()
 545                 {
 546                         return ToXml ().ToString ();
 547                 }
 548
 549                 public virtual SecurityElement ToXml ()
 550                 {
 551                         SecurityElement se = new SecurityElement (tagName);
 552                         se.AddAttribute ("class", GetType ().FullName);
 553                         se.AddAttribute ("version", version.ToString ());
 554                         if (state == PermissionState.Unrestricted)
 555                                 se.AddAttribute ("Unrestricted", "true");
 556
 557                         // required for permissions that do not implement IUnrestrictedPermission
 558                         foreach (IPermission p in list) {
 559                                 se.AddChild (p.ToXml ());
 560                         }
 561                         return se;
 562                 }
 563
 564                 public virtual PermissionSet Union (PermissionSet other)
 565                 {
 566                         if (other == null)
 567                                 return this.Copy ();
 568
 569                         PermissionSet copy = this.Copy ();
 570                         if (this.IsUnrestricted () || other.IsUnrestricted ()) {
 571                                 // so we keep the "right" type
 572                                 copy.Clear ();
 573                                 copy.state = PermissionState.Unrestricted;
 574                                 // copy all permissions that do not implement IUnrestrictedPermission
 575                                 foreach (IPermission p in this.list) {
 576                                         if (!(p is IUnrestrictedPermission))
 577                                                 copy.AddPermission (p);
 578                                 }
 579                                 foreach (IPermission p in other.list) {
 580                                         if (!(p is IUnrestrictedPermission))
 581                                                 copy.AddPermission (p);
 582                                 }
 583                         }
 584                         else {
 585                                 // PermissionState.None -> copy all permissions
 586                                 foreach (IPermission p in other.list) {
 587                                         copy.AddPermission (p);
 588                                 }
 589                         }
 590                         return copy;
 591                 }
 592
 593                 public virtual int Count {
 594                         get { return list.Count; }
 595                 }
 596
 597                 public virtual bool IsSynchronized {
 598                         get { return list.IsSynchronized; }
 599                 }
 600
 601                 public virtual bool IsReadOnly {
 602                         get { return false; } // always false
 603                 }
 604
 605                 public virtual object SyncRoot {
 606                         get { return this; }
 607                 }
 608
 609                 internal bool DeclarativeSecurity {
 610                         get { return _declsec; }
 611                         set { _declsec = value; }
 612                 }
 613
 614                 [MonoTODO()]
 615                 void IDeserializationCallback.OnDeserialization (object sender)
 616                 {
 617                 }
 618
 619 #if NET_2_0
 620                 [ComVisible (false)]
 621                 public override bool Equals (object obj)
 622                 {
 623                         if (obj == null)
 624                                 return false;
 625                         PermissionSet ps = (obj as PermissionSet);
 626                         if (ps == null)
 627                                 return false;
 628                         if (list.Count != ps.Count)
 629                                 return false;
 630
 631                         for (int i=0; i < list.Count; i++) {
 632                                 bool found = false;
 633                                 for (int j=0; i < ps.list.Count; j++) {
 634                                         if (list [i].Equals (ps.list [j])) {
 635                                                 found = true;
 636                                                 break;
 637                                         }
 638                                 }
 639                                 if (!found)
 640                                         return false;
 641                         }
 642                         return true;
 643                 }
 644
 645                 [ComVisible (false)]
 646                 public override int GetHashCode ()
 647                 {
 648                         return (list.Count == 0) ? (int) state : base.GetHashCode ();
 649                 }
 650
 651                 [MonoTODO ("what's it doing here?")]
 652                 static public void RevertAssert ()
 653                 {
 654                         // FIXME: There's probably a reason this was added here ?
 655                         CodeAccessPermission.RevertAssert ();
 656                 }
 657 #endif
 658
 659                 // internal
 660
 661                 internal PolicyLevel Resolver {
 662                         get { return _policyLevel; }
 663                         set { _policyLevel = value; }
 664                 }
 665
 666                 internal bool ProcessFrame (SecurityFrame frame, ref Assembly current, ref AppDomain domain)
 667                 {
 668                         if (IsUnrestricted ()) {
 669                                 // we request unrestricted
 670                                 if (frame.Deny != null) {
 671                                         // but have restrictions (some denied permissions)
 672                                         CodeAccessPermission.ThrowSecurityException (this, "Deny", frame, SecurityAction.Demand, null);
 673                                 } else if (frame.PermitOnly != null) {
 674                                         // but have restrictions (only some permitted permissions)
 675                                         CodeAccessPermission.ThrowSecurityException (this, "PermitOnly", frame, SecurityAction.Demand, null);
 676                                 }
 677                         }
 678
 679                         // skip next steps if no Assert, Deny or PermitOnly are present
 680                         if (frame.HasStackModifiers) {
 681                                 foreach (CodeAccessPermission cap in list) {
 682                                         if (cap.ProcessFrame (frame))
 683                                                 return true; // Assert reached - abort stack walk!
 684                                 }
 685                         }
 686
 687                         // however the "final" grant set is resolved by assembly, so
 688                         // there's no need to check it every time (just when we're
 689                         // changing assemblies between frames).
 690                         if (frame.Assembly != current) {
 691                                 CheckAssembly (current, frame);
 692                                 current = frame.Assembly;
 693                         }
 694
 695                         if (frame.Domain != domain) {
 696                                 CheckAppDomain (domain, frame);
 697                                 domain = frame.Domain;
 698                         }
 699
 700                         return false;
 701                 }
 702
 703                 internal void CheckAssembly (Assembly a, SecurityFrame frame)
 704                 {
 705                         if (!SecurityManager.IsGranted (a, this, false)) {
 706                                 CodeAccessPermission.ThrowSecurityException (this, "Demand failed assembly permissions checks.",
 707                                         frame, SecurityAction.Demand, null);
 708                         }
 709                 }
 710
 711                 internal void CheckAppDomain (AppDomain domain, SecurityFrame frame)
 712                 {
 713                         if (!SecurityManager.IsGranted (domain, this)) {
 714                                 CodeAccessPermission.ThrowSecurityException (this, "Demand failed appdomain permissions checks.",
 715                                         frame, SecurityAction.Demand, null);
 716                         }
 717                 }
 718
 719                 // 2.0 metadata format
 720
 721                 internal static PermissionSet CreateFromBinaryFormat (byte[] data)
 722                 {
 723                         if ((data == null) || (data [0] != 0x2E) || (data.Length < 2)) {
 724                                 string msg = Locale.GetText ("Invalid data in 2.0 metadata format.");
 725                                 throw new SecurityException (msg);
 726                         }
 727
 728                         int pos = 1;
 729                         int numattr = ReadEncodedInt (data, ref pos);
 730                         PermissionSet ps = new PermissionSet (PermissionState.None);
 731                         for (int i = 0; i < numattr; i++) {
 732                                 IPermission p = ProcessAttribute (data, ref pos);
 733                                 if (p == null) {
 734                                         string msg = Locale.GetText ("Unsupported data found in 2.0 metadata format.");
 735                                         throw new SecurityException (msg);
 736                                 }
 737                                 ps.AddPermission (p);
 738                         }
 739                         return ps;
 740                 }
 741
 742                 internal static int ReadEncodedInt (byte[] data, ref int position)
 743                 {
 744                         int len = 0;
 745                         if ((data [position] & 0x80) == 0) {
 746                                 len = data [position];
 747                                 position ++;
 748                         } else if ((data [position] & 0x40) == 0) {
 749                                 len = ((data [position] & 0x3f) << 8 | data [position + 1]);
 750                                 position += 2;
 751                         } else {
 752                                 len = (((data [position] & 0x1f) << 24) | (data [position + 1] << 16) |
 753                                         (data [position + 2] << 8) | (data [position + 3]));
 754                                 position += 4;
 755                         }
 756                         return len;
 757                 }
 758
 759                 static object[] action = new object [1] { (SecurityAction) 0 };
 760
 761                 // TODO: add support for arrays and enums
 762                 internal static IPermission ProcessAttribute (byte[] data, ref int position)
 763                 {
 764                         int clen = ReadEncodedInt (data, ref position);
 765                         string cnam = Encoding.UTF8.GetString (data, position, clen);
 766                         position += clen;
 767
 768                         // TODO: Unification
 769                         Type secattr = Type.GetType (cnam);
 770                         SecurityAttribute sa = (Activator.CreateInstance (secattr, action) as SecurityAttribute);
 771                         if (sa == null)
 772                                 return null;
 773
 774                         /*int optionalParametersLength =*/ ReadEncodedInt (data, ref position);
 775                         int numberOfParameters = ReadEncodedInt (data, ref position);
 776                         for (int j=0; j < numberOfParameters; j++) {
 777                                 bool property = false;
 778                                 switch (data [position++]) {
 779                                 case 0x53: // field (technically possible and working)
 780                                         property = false;
 781                                         break;
 782                                 case 0x54: // property (common case)
 783                                         property = true;
 784                                         break;
 785                                 default:
 786                                         return null;
 787                                 }
 788
 789                                 bool array = false;
 790                                 byte type = data [position++];
 791                                 if (type == 0x1D) {
 792                                         array = true;
 793                                         type = data [position++];
 794                                 }
 795
 796                                 int plen = ReadEncodedInt (data, ref position);
 797                                 string pnam = Encoding.UTF8.GetString (data, position, plen);
 798                                 position += plen;
 799
 800                                 int arrayLength = 1;
 801                                 if (array) {
 802                                         arrayLength = BitConverter.ToInt32 (data, position);
 803                                         position += 4;
 804                                 }
 805
 806                                 object obj = null;
 807                                 object[] arrayIndex = null;
 808                                 for (int i = 0; i < arrayLength; i++) {
 809                                         if (array) {
 810                                                 // TODO - setup index
 811                                         }
 812
 813                                         // sadly type values doesn't match ther TypeCode enum :(
 814                                         switch (type) {
 815                                         case 0x02: // MONO_TYPE_BOOLEAN
 816                                                 obj = (object) Convert.ToBoolean (data [position++]);
 817                                                 break;
 818                                         case 0x03: // MONO_TYPE_CHAR
 819                                                 obj = (object) Convert.ToChar (data [position]);
 820                                                 position += 2;
 821                                                 break;
 822                                         case 0x04: // MONO_TYPE_I1
 823                                                 obj = (object) Convert.ToSByte (data [position++]);
 824                                                 break;
 825                                         case 0x05: // MONO_TYPE_U1
 826                                                 obj = (object) Convert.ToByte (data [position++]);
 827                                                 break;
 828                                         case 0x06: // MONO_TYPE_I2
 829                                                 obj = (object) Convert.ToInt16 (data [position]);
 830                                                 position += 2;
 831                                                 break;
 832                                         case 0x07: // MONO_TYPE_U2
 833                                                 obj = (object) Convert.ToUInt16 (data [position]);
 834                                                 position += 2;
 835                                                 break;
 836                                         case 0x08: // MONO_TYPE_I4
 837                                                 obj = (object) Convert.ToInt32 (data [position]);
 838                                                 position += 4;
 839                                                 break;
 840                                         case 0x09: // MONO_TYPE_U4
 841                                                 obj = (object) Convert.ToUInt32 (data [position]);
 842                                                 position += 4;
 843                                                 break;
 844                                         case 0x0A: // MONO_TYPE_I8
 845                                                 obj = (object) Convert.ToInt64 (data [position]);
 846                                                 position += 8;
 847                                                 break;
 848                                         case 0x0B: // MONO_TYPE_U8
 849                                                 obj = (object) Convert.ToUInt64 (data [position]);
 850                                                 position += 8;
 851                                                 break;
 852                                         case 0x0C: // MONO_TYPE_R4
 853                                                 obj = (object) Convert.ToSingle (data [position]);
 854                                                 position += 4;
 855                                                 break;
 856                                         case 0x0D: // MONO_TYPE_R8
 857                                                 obj = (object) Convert.ToDouble (data [position]);
 858                                                 position += 8;
 859                                                 break;
 860                                         case 0x0E: // MONO_TYPE_STRING
 861                                                 string s = null;
 862                                                 if (data [position] != 0xFF) {
 863                                                         int slen = ReadEncodedInt (data, ref position);
 864                                                         s = Encoding.UTF8.GetString (data, position, slen);
 865                                                         position += slen;
 866                                                 } else {
 867                                                         position++;
 868                                                 }
 869                                                 obj = (object) s;
 870                                                 break;
 871                                         case 0x50: // special for TYPE
 872                                                 int tlen = ReadEncodedInt (data, ref position);
 873                                                 obj = (object) Type.GetType (Encoding.UTF8.GetString (data, position, tlen));
 874                                                 position += tlen;
 875                                                 break;
 876                                         default:
 877                                                 return null; // unsupported
 878                                         }
 879
 880                                         if (property) {
 881                                                 PropertyInfo pi = secattr.GetProperty (pnam);
 882                                                 pi.SetValue (sa, obj, arrayIndex);
 883                                         } else {
 884                                                 FieldInfo fi = secattr.GetField (pnam);
 885                                                 fi.SetValue (sa, obj);
 886                                         }
 887                                 }
 888                         }
 889                         return sa.CreatePermission ();
 890                 }
 891         }
 892 }