mcs/class/corlib/System.Security.Policy/PolicyLevel.cs

   1 //
   2 // System.Security.Policy.PolicyLevel.cs
   3 //
   4 // Authors:
   5 //      Nick Drochak (ndrochak@gol.com)
   6 //      Duncan Mak (duncan@ximian.com)
   7 //      Sebastien Pouliot  <sebastien@ximian.com>
   8 //
   9 // (C) 2001 Nick Drochak
  10 // (C) 2003 Duncan Mak, Ximian Inc.
  11 // Portions (C) 2004 Motus Technologies Inc. (http://www.motus.com)
  12 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
  13 //
  14 // Permission is hereby granted, free of charge, to any person obtaining
  15 // a copy of this software and associated documentation files (the
  16 // "Software"), to deal in the Software without restriction, including
  17 // without limitation the rights to use, copy, modify, merge, publish,
  18 // distribute, sublicense, and/or sell copies of the Software, and to
  19 // permit persons to whom the Software is furnished to do so, subject to
  20 // the following conditions:
  21 //
  22 // The above copyright notice and this permission notice shall be
  23 // included in all copies or substantial portions of the Software.
  24 //
  25 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  29 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  30 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  31 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  32 //
  33
  34 using System.Collections; // for IList
  35 using System.Globalization;
  36 using System.IO;
  37 using System.Reflection;
  38 using System.Runtime.InteropServices;
  39 using System.Security.Permissions;
  40
  41 using Mono.Xml;
  42
  43 namespace System.Security.Policy {
  44
  45         [Serializable]
  46 #if NET_2_0
  47         [ComVisible (true)]
  48 #endif
  49         public sealed class PolicyLevel {
  50
  51                 string label;
  52                 CodeGroup root_code_group;
  53                 private ArrayList full_trust_assemblies;
  54                 private ArrayList named_permission_sets;
  55                 private string _location;
  56                 private PolicyLevelType _type;
  57                 private Hashtable fullNames;
  58
  59                 internal PolicyLevel (string label, PolicyLevelType type)
  60                 {
  61                         this.label = label;
  62                         _type = type;
  63                         full_trust_assemblies = new ArrayList ();
  64                         named_permission_sets = new ArrayList ();
  65                 }
  66
  67                 internal PolicyLevel (string label, PolicyLevelType type, string filename)
  68                         : this (label, type)
  69                 {
  70                         LoadFromFile (filename);
  71                 }
  72
  73                 internal void LoadFromFile (string filename)
  74                 {
  75                         bool loaded = false;
  76                         try {
  77                                 // check for policy file
  78                                 if (!File.Exists (filename)) {
  79                                         // if it doesn't exist use the default configuration (like Fx 2.0)
  80                                         // ref: http://blogs.msdn.com/shawnfa/archive/2004/04/21/117833.aspx
  81                                         string defcfg = filename + ".default";
  82                                         if (File.Exists (defcfg)) {
  83                                                 // create policy from default file
  84                                                 File.Copy (defcfg, filename);
  85                                         }
  86                                 }
  87                                 // load security policy configuration
  88                                 if (File.Exists (filename)) {
  89                                         using (StreamReader sr = File.OpenText (filename)) {
  90                                                 LoadFromString (sr.ReadToEnd ());
  91                                         }
  92                                         loaded = true;
  93                                 }
  94                                 else {
  95                                         CreateFromHardcodedDefault (_type);
  96                                         loaded = true;
  97                                         Save ();
  98                                 }
  99                         }
 100                         catch {
 101                                 // this can fail in many ways include
 102                                 // * can't lookup policy (path discovery);
 103                                 // * can't copy default file to policy
 104                                 // * can't read policy file;
 105                                 // * can't save hardcoded policy to filename
 106                                 // * can't decode policy file
 107                                 if (!loaded)
 108                                         CreateFromHardcodedDefault (_type);
 109                         }
 110                         finally {
 111                                 _location = filename;
 112                         }
 113                 }
 114
 115                 internal void LoadFromString (string xml)
 116                 {
 117                         SecurityParser parser = new SecurityParser ();
 118                         parser.LoadXml (xml);
 119                         // configuration / mscorlib / security / policy / PolicyLevel
 120                         SecurityElement configuration = parser.ToXml ();
 121                         if (configuration.Tag != "configuration")
 122                                 throw new ArgumentException (Locale.GetText ("missing <configuration> root element"));
 123                         SecurityElement mscorlib = (SecurityElement) configuration.Children [0];
 124                         if (mscorlib.Tag != "mscorlib")
 125                                 throw new ArgumentException (Locale.GetText ("missing <mscorlib> tag"));
 126                         SecurityElement security = (SecurityElement) mscorlib.Children [0];
 127                         if (security.Tag != "security")
 128                                 throw new ArgumentException (Locale.GetText ("missing <security> tag"));
 129                         SecurityElement policy = (SecurityElement) security.Children [0];
 130                         if (policy.Tag != "policy")
 131                                 throw new ArgumentException (Locale.GetText ("missing <policy> tag"));
 132                         SecurityElement policyLevel = (SecurityElement) policy.Children [0];
 133                         FromXml (policyLevel);
 134                 }
 135
 136                 // properties
 137
 138                 public IList FullTrustAssemblies
 139                 {
 140                         get { return full_trust_assemblies; }
 141                 }
 142
 143                 public string Label {
 144                         get { return label; }
 145                 }
 146
 147                 public IList NamedPermissionSets {
 148                         get { return named_permission_sets; }
 149                 }
 150
 151                 public CodeGroup RootCodeGroup {
 152                         get { return root_code_group; }
 153                         set {
 154                                 if (value == null)
 155                                         throw new ArgumentNullException ("value");
 156                                 root_code_group = value;
 157                         }
 158                 }
 159
 160                 public string StoreLocation {
 161                         get { return _location; }
 162                 }
 163
 164 #if NET_2_0
 165                 [ComVisible (false)]
 166                 public PolicyLevelType Type {
 167                         get { return _type; }
 168                 }
 169 #endif
 170
 171                 // methods
 172
 173                 public void AddFullTrustAssembly (StrongName sn)
 174                 {
 175                         if (sn == null)
 176                                 throw new ArgumentNullException ("sn");
 177
 178                         StrongNameMembershipCondition snMC = new StrongNameMembershipCondition(
 179                                 sn.PublicKey, sn.Name, sn.Version);
 180
 181                         AddFullTrustAssembly (snMC);
 182                 }
 183
 184                 public void AddFullTrustAssembly (StrongNameMembershipCondition snMC)
 185                 {
 186                         if (snMC == null)
 187                                 throw new ArgumentNullException ("snMC");
 188
 189                         foreach (StrongNameMembershipCondition sn in full_trust_assemblies) {
 190                                 if (sn.Equals (snMC)) {
 191                                         throw new ArgumentException (Locale.GetText ("sn already has full trust."));
 192                                 }
 193                         }
 194                         full_trust_assemblies.Add (snMC);
 195                 }
 196
 197                 public void AddNamedPermissionSet (NamedPermissionSet permSet)
 198                 {
 199                         if (permSet == null)
 200                                 throw new ArgumentNullException ("permSet");
 201
 202                         foreach (NamedPermissionSet n in named_permission_sets) {
 203                                 if (permSet.Name == n.Name) {
 204                                         throw new ArgumentException (
 205                                                 Locale.GetText ("This NamedPermissionSet is the same an existing NamedPermissionSet."));
 206                                 }
 207                         }
 208                         named_permission_sets.Add (permSet.Copy ());
 209                 }
 210
 211                 public NamedPermissionSet ChangeNamedPermissionSet (string name, PermissionSet pSet)
 212                 {
 213                         if (name == null)
 214                                 throw new ArgumentNullException ("name");
 215                         if (pSet == null)
 216                                 throw new ArgumentNullException ("pSet");
 217                         if (DefaultPolicies.ReservedNames.IsReserved (name))
 218                                 throw new ArgumentException (Locale.GetText ("Reserved name"));
 219
 220                         foreach (NamedPermissionSet n in named_permission_sets) {
 221                                 if (name == n.Name) {
 222                                         named_permission_sets.Remove (n);
 223                                         AddNamedPermissionSet (new NamedPermissionSet (name, pSet));
 224                                         return n;
 225                                 }
 226                         }
 227                         throw new ArgumentException (Locale.GetText ("PermissionSet not found"));
 228                 }
 229
 230                 public static PolicyLevel CreateAppDomainLevel ()
 231                 {
 232                         NamedPermissionSet fullTrust = new NamedPermissionSet ("FullTrust", PermissionState.Unrestricted);
 233                         UnionCodeGroup cg = new UnionCodeGroup (new AllMembershipCondition (), new PolicyStatement (fullTrust));
 234                         cg.Name = "All_Code";
 235                         PolicyLevel pl = new PolicyLevel ("AppDomain", PolicyLevelType.AppDomain);
 236                         pl.RootCodeGroup = cg;
 237                         pl.Reset ();
 238                         return pl;
 239                 }
 240
 241                 public void FromXml (SecurityElement e)
 242                 {
 243                         if (e == null)
 244                                 throw new ArgumentNullException ("e");
 245 // MS doesn't throw an exception for this case
 246 //                      if (e.Tag != "PolicyLevel")
 247 //                              throw new ArgumentException (Locale.GetText ("Invalid XML"));
 248
 249                         SecurityElement sc = e.SearchForChildByTag ("SecurityClasses");
 250                         if ((sc != null) && (sc.Children != null) && (sc.Children.Count > 0)) {
 251                                 fullNames = new Hashtable (sc.Children.Count);
 252                                 foreach (SecurityElement se in sc.Children) {
 253                                         fullNames.Add (se.Attributes ["Name"], se.Attributes ["Description"]);
 254                                 }
 255                         }
 256
 257                         SecurityElement nps = e.SearchForChildByTag ("NamedPermissionSets");
 258                         if ((nps != null) && (nps.Children != null) && (nps.Children.Count > 0)) {
 259                                 named_permission_sets.Clear ();
 260                                 foreach (SecurityElement se in nps.Children) {
 261                                         NamedPermissionSet n = new NamedPermissionSet ();
 262                                         n.Resolver = this;
 263                                         n.FromXml (se);
 264                                         named_permission_sets.Add (n);
 265                                 }
 266                         }
 267
 268                         SecurityElement cg = e.SearchForChildByTag ("CodeGroup");
 269                         if ((cg != null) && (cg.Children != null) && (cg.Children.Count > 0)) {
 270                                 root_code_group = CodeGroup.CreateFromXml (cg, this);
 271                         }
 272                         else
 273                                 throw new ArgumentException (Locale.GetText ("Missing Root CodeGroup"));
 274
 275                         SecurityElement fta = e.SearchForChildByTag ("FullTrustAssemblies");
 276                         if ((fta != null) && (fta.Children != null) && (fta.Children.Count > 0)) {
 277                                 full_trust_assemblies.Clear ();
 278                                 foreach (SecurityElement se in fta.Children) {
 279                                         if (se.Tag != "IMembershipCondition")
 280                                                 throw new ArgumentException (Locale.GetText ("Invalid XML"));
 281                                         string className = se.Attribute ("class");
 282                                         if (className.IndexOf ("StrongNameMembershipCondition") < 0)
 283                                                 throw new ArgumentException (Locale.GetText ("Invalid XML - must be StrongNameMembershipCondition"));
 284                                         // we directly use StrongNameMembershipCondition
 285                                         full_trust_assemblies.Add (new StrongNameMembershipCondition (se));
 286                                 }
 287                         }
 288                 }
 289
 290                 public NamedPermissionSet GetNamedPermissionSet (string name)
 291                 {
 292                         if (name == null)
 293                                 throw new ArgumentNullException ("name");
 294
 295                         foreach (NamedPermissionSet n in named_permission_sets) {
 296                                 if (n.Name == name)
 297                                         return (NamedPermissionSet) n.Copy ();
 298                         }
 299                         return null;
 300                 }
 301
 302                 public void Recover ()
 303                 {
 304                         if (_location == null) {
 305                                 string msg = Locale.GetText ("Only file based policies may be recovered.");
 306                                 throw new PolicyException (msg);
 307                         }
 308
 309                         string backup = _location + ".backup";
 310                         if (!File.Exists (backup)) {
 311                                 string msg = Locale.GetText ("No policy backup exists.");
 312                                 throw new PolicyException (msg);
 313                         }
 314
 315                         try {
 316                                 File.Copy (backup, _location, true);
 317                         }
 318                         catch (Exception e) {
 319                                 string msg = Locale.GetText ("Couldn't replace the policy file with it's backup.");
 320                                 throw new PolicyException (msg, e);
 321                         }
 322                 }
 323
 324                 public void RemoveFullTrustAssembly (StrongName sn)
 325                 {
 326                         if (sn == null)
 327                                 throw new ArgumentNullException ("sn");
 328
 329                         StrongNameMembershipCondition s = new StrongNameMembershipCondition (sn.PublicKey, sn.Name, sn.Version);
 330                         RemoveFullTrustAssembly (s);
 331                 }
 332
 333                 public void RemoveFullTrustAssembly (StrongNameMembershipCondition snMC)
 334                 {
 335                         if (snMC == null)
 336                                 throw new ArgumentNullException ("snMC");
 337
 338                         if (((IList) full_trust_assemblies).Contains (snMC))
 339                                 ((IList) full_trust_assemblies).Remove (snMC);
 340
 341                         else
 342                                 throw new ArgumentException (
 343                                         Locale.GetText ("sn does not have full trust."));
 344                 }
 345
 346                 public NamedPermissionSet RemoveNamedPermissionSet (NamedPermissionSet permSet)
 347                 {
 348                         if (permSet == null)
 349                                 throw new ArgumentNullException ("permSet");
 350
 351                         return RemoveNamedPermissionSet (permSet.Name);
 352                 }
 353
 354                 public NamedPermissionSet RemoveNamedPermissionSet (string name)
 355                 {
 356                         if (name == null)
 357                                 throw new ArgumentNullException ("name");
 358                         if (DefaultPolicies.ReservedNames.IsReserved (name))
 359                                 throw new ArgumentException (Locale.GetText ("Reserved name"));
 360
 361                         foreach (NamedPermissionSet nps in named_permission_sets) {
 362                                 if (name == nps.Name) {
 363                                         named_permission_sets.Remove (nps);
 364                                         return nps;
 365                                 }
 366                         }
 367                         string msg = String.Format (Locale.GetText ("Name '{0}' cannot be found."), name);
 368                         throw new ArgumentException (msg, "name");
 369                 }
 370
 371                 public void Reset ()
 372                 {
 373                         if (fullNames != null)
 374                                 fullNames.Clear ();
 375                         full_trust_assemblies.Clear ();
 376                         named_permission_sets.Clear ();
 377
 378                         if (_type != PolicyLevelType.AppDomain) {
 379                                 // because the policy doesn't exist LoadFromFile will try to
 380                                 // 1. use the .default file if existing (like Fx 2.0 does); or
 381                                 // 2. use the hard-coded default values
 382                                 // and recreate a policy file
 383                                 if ((_location != null) && (File.Exists (_location))) {
 384                                         try {
 385                                                 File.Delete (_location);
 386                                         }
 387                                         catch {}
 388                                 }
 389                                 LoadFromFile (_location);
 390                         }
 391                         else {
 392                                 named_permission_sets.Add (DefaultPolicies.LocalIntranet);
 393                                 named_permission_sets.Add (DefaultPolicies.Internet);
 394                                 named_permission_sets.Add (DefaultPolicies.SkipVerification);
 395                                 named_permission_sets.Add (DefaultPolicies.Execution);
 396                                 named_permission_sets.Add (DefaultPolicies.Nothing);
 397                                 named_permission_sets.Add (DefaultPolicies.Everything);
 398                                 named_permission_sets.Add (DefaultPolicies.FullTrust);
 399                         }
 400                 }
 401
 402                 public PolicyStatement Resolve (Evidence evidence)
 403                 {
 404                         if (evidence == null)
 405                                 throw new ArgumentNullException ("evidence");
 406
 407                         PolicyStatement ps = root_code_group.Resolve (evidence);
 408                         return ((ps != null) ? ps : PolicyStatement.Empty ());
 409                 }
 410
 411                 public CodeGroup ResolveMatchingCodeGroups (Evidence evidence)
 412                 {
 413                         if (evidence == null)
 414                                 throw new ArgumentNullException ("evidence");
 415
 416                         CodeGroup cg = root_code_group.ResolveMatchingCodeGroups (evidence);
 417                         // TODO
 418                         return ((cg != null) ? cg : null);
 419
 420                 }
 421
 422                 public SecurityElement ToXml ()
 423                 {
 424                         Hashtable fullNames = new Hashtable ();
 425                         // only StrongNameMembershipCondition so no need to loop
 426                         if (full_trust_assemblies.Count > 0) {
 427                                 if (!fullNames.Contains ("StrongNameMembershipCondition")) {
 428                                         fullNames.Add ("StrongNameMembershipCondition", typeof (StrongNameMembershipCondition).FullName);
 429                                 }
 430                         }
 431
 432                         SecurityElement namedPSs = new SecurityElement ("NamedPermissionSets");
 433                         foreach (NamedPermissionSet nps in named_permission_sets) {
 434                                 SecurityElement se = nps.ToXml ();
 435                                 object objectClass = se.Attributes ["class"];
 436                                 if (!fullNames.Contains (objectClass)) {
 437                                         fullNames.Add (objectClass, nps.GetType ().FullName);
 438                                 }
 439                                 namedPSs.AddChild (se);
 440                         }
 441
 442                         SecurityElement fta = new SecurityElement ("FullTrustAssemblies");
 443                         foreach (StrongNameMembershipCondition snmc in full_trust_assemblies) {
 444                                 fta.AddChild (snmc.ToXml (this));
 445                         }
 446
 447                         SecurityElement security_classes = new SecurityElement ("SecurityClasses");
 448                         if (fullNames.Count > 0) {
 449                                 foreach (DictionaryEntry de in fullNames) {
 450                                         SecurityElement sc = new SecurityElement ("SecurityClass");
 451                                         sc.AddAttribute ("Name", (string)de.Key);
 452                                         sc.AddAttribute ("Description", (string)de.Value);
 453                                         security_classes.AddChild (sc);
 454                                 }
 455                         }
 456
 457                         SecurityElement element = new SecurityElement (typeof (System.Security.Policy.PolicyLevel).Name);
 458                         element.AddAttribute ("version", "1");
 459                         element.AddChild (security_classes);
 460                         element.AddChild (namedPSs);
 461                         if (root_code_group != null) {
 462                                 element.AddChild (root_code_group.ToXml (this));
 463                         }
 464                         element.AddChild (fta);
 465
 466                         return element;
 467                 }
 468
 469                 // internal stuff
 470
 471                 // NOTE: Callers are expected to check for ControlPolicy
 472                 internal void Save ()
 473                 {
 474                         if (_type == PolicyLevelType.AppDomain) {
 475                                 throw new PolicyException (Locale.GetText (
 476                                         "Can't save AppDomain PolicyLevel"));
 477                         }
 478
 479                         if (_location != null) {
 480                                 try {
 481                                         if (File.Exists (_location)) {
 482                                                 File.Copy (_location, _location + ".backup", true);
 483                                         }
 484                                 }
 485                                 catch (Exception) {
 486                                 }
 487                                 finally {
 488                                         using (StreamWriter sw = new StreamWriter (_location)) {
 489                                                 sw.Write (ToXml ().ToString ());
 490                                                 sw.Close ();
 491                                         }
 492                                 }
 493                         }
 494                 }
 495
 496                 // TODO : hardcode defaults in case
 497                 // (a) the specified policy file doesn't exists; and
 498                 // (b) no corresponding default policy file exists
 499                 internal void CreateFromHardcodedDefault (PolicyLevelType type)
 500                 {
 501                         PolicyStatement psu = new PolicyStatement (new PermissionSet (PermissionState.Unrestricted));
 502
 503                         switch (type) {
 504                         case PolicyLevelType.Machine:
 505                                 // by default all stuff is in the machine policy...
 506                                 root_code_group = new UnionCodeGroup (new ZoneMembershipCondition (SecurityZone.MyComputer), psu);
 507                                 root_code_group.Name = "All_Code";
 508                                 break;
 509                         case PolicyLevelType.User:
 510                         case PolicyLevelType.Enterprise:
 511                         case PolicyLevelType.AppDomain:
 512                                 // while the other policies don't restrict anything
 513                                 root_code_group = new UnionCodeGroup (new AllMembershipCondition (), psu);
 514                                 root_code_group.Name = "All_Code";
 515                                 break;
 516                         }
 517
 518                         named_permission_sets.Clear ();
 519                         named_permission_sets.Add (DefaultPolicies.LocalIntranet);
 520                         named_permission_sets.Add (DefaultPolicies.Internet);
 521                         named_permission_sets.Add (DefaultPolicies.SkipVerification);
 522                         named_permission_sets.Add (DefaultPolicies.Execution);
 523                         named_permission_sets.Add (DefaultPolicies.Nothing);
 524                         named_permission_sets.Add (DefaultPolicies.Everything);
 525                         named_permission_sets.Add (DefaultPolicies.FullTrust);
 526                 }
 527
 528                 internal string ResolveClassName (string className)
 529                 {
 530                         if (fullNames != null) {
 531                                 object name = fullNames [className];
 532                                 if (name != null)
 533                                         return (string) name;
 534                         }
 535                         return className;
 536                 }
 537         }
 538 }