mcs/class/System/System.Net/ServicePointManager.cs

   1 //
   2 // System.Net.ServicePointManager
   3 //
   4 // Authors:
   5 //   Lawrence Pit (loz@cable.a2000.nl)
   6 //   Gonzalo Paniagua Javier (gonzalo@novell.com)
   7 //
   8 // Copyright (c) 2003-2010 Novell, Inc (http://www.novell.com)
   9 //
  10
  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 #if SECURITY_DEP
  33
  34 #if MONOTOUCH
  35 using Mono.Security.Protocol.Tls;
  36 using MSX = Mono.Security.X509;
  37 using Mono.Security.X509.Extensions;
  38 #else
  39 extern alias MonoSecurity;
  40 using MonoSecurity::Mono.Security.X509.Extensions;
  41 using MonoSecurity::Mono.Security.Protocol.Tls;
  42 using MSX = MonoSecurity::Mono.Security.X509;
  43 #endif
  44
  45 using System.Text.RegularExpressions;
  46 #endif
  47
  48 using System;
  49 using System.Collections;
  50 using System.Collections.Specialized;
  51 using System.Configuration;
  52 using System.Net.Configuration;
  53 using System.Security.Cryptography.X509Certificates;
  54
  55 using System.Globalization;
  56 using System.Net.Security;
  57
  58 //
  59 // notes:
  60 // A service point manager manages service points (duh!).
  61 // A service point maintains a list of connections (per scheme + authority).
  62 // According to HttpWebRequest.ConnectionGroupName each connection group
  63 // creates additional connections. therefor, a service point has a hashtable
  64 // of connection groups where each value is a list of connections.
  65 //
  66 // when we need to make an HttpWebRequest, we need to do the following:
  67 // 1. find service point, given Uri and Proxy
  68 // 2. find connection group, given service point and group name
  69 // 3. find free connection in connection group, or create one (if ok due to limits)
  70 // 4. lease connection
  71 // 5. execute request
  72 // 6. when finished, return connection
  73 //
  74
  75
  76 namespace System.Net
  77 {
  78         public class ServicePointManager {
  79                 class SPKey {
  80                         Uri uri; // schema/host/port
  81                         Uri proxy;
  82                         bool use_connect;
  83
  84                         public SPKey (Uri uri, Uri proxy, bool use_connect) {
  85                                 this.uri = uri;
  86                                 this.proxy = proxy;
  87                                 this.use_connect = use_connect;
  88                         }
  89
  90                         public Uri Uri {
  91                                 get { return uri; }
  92                         }
  93
  94                         public bool UseConnect {
  95                                 get { return use_connect; }
  96                         }
  97
  98                         public bool UsesProxy {
  99                                 get { return proxy != null; }
 100                         }
 101
 102                         public override int GetHashCode () {
 103                                 int hash = 23;
 104                                 hash = hash * 31 + ((use_connect) ? 1 : 0);
 105                                 hash = hash * 31 + uri.GetHashCode ();
 106                                 hash = hash * 31 + (proxy != null ? proxy.GetHashCode () : 0);
 107                                 return hash;
 108                         }
 109
 110                         public override bool Equals (object obj) {
 111                                 SPKey other = obj as SPKey;
 112                                 if (obj == null) {
 113                                         return false;
 114                                 }
 115
 116                                 if (!uri.Equals (other.uri))
 117                                         return false;
 118                                 if (use_connect != other.use_connect || UsesProxy != other.UsesProxy)
 119                                         return false;
 120                                 if (UsesProxy && !proxy.Equals (other.proxy))
 121                                         return false;
 122                                 return true;
 123                         }
 124                 }
 125
 126                 private static HybridDictionary servicePoints = new HybridDictionary ();
 127
 128                 // Static properties
 129
 130                 private static ICertificatePolicy policy = new DefaultCertificatePolicy ();
 131                 private static int defaultConnectionLimit = DefaultPersistentConnectionLimit;
 132                 private static int maxServicePointIdleTime = 900000; // 15 minutes
 133                 private static int maxServicePoints = 0;
 134                 private static bool _checkCRL = false;
 135                 private static SecurityProtocolType _securityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls;
 136
 137 #if TARGET_JVM
 138                 static bool expectContinue = false;
 139 #else
 140                 static bool expectContinue = true;
 141 #endif
 142                 static bool useNagle;
 143                 static RemoteCertificateValidationCallback server_cert_cb;
 144                 static bool tcp_keepalive;
 145                 static int tcp_keepalive_time;
 146                 static int tcp_keepalive_interval;
 147
 148                 // Fields
 149
 150                 public const int DefaultNonPersistentConnectionLimit = 4;
 151 #if MONOTOUCH
 152                 public const int DefaultPersistentConnectionLimit = 10;
 153 #else
 154                 public const int DefaultPersistentConnectionLimit = 2;
 155 #endif
 156
 157 #if !NET_2_1
 158                 const string configKey = "system.net/connectionManagement";
 159                 static ConnectionManagementData manager;
 160 #endif
 161
 162                 static ServicePointManager ()
 163                 {
 164 #if !NET_2_1
 165 #if CONFIGURATION_DEP
 166                         object cfg = ConfigurationManager.GetSection (configKey);
 167                         ConnectionManagementSection s = cfg as ConnectionManagementSection;
 168                         if (s != null) {
 169                                 manager = new ConnectionManagementData (null);
 170                                 foreach (ConnectionManagementElement e in s.ConnectionManagement)
 171                                         manager.Add (e.Address, e.MaxConnection);
 172
 173                                 defaultConnectionLimit = (int) manager.GetMaxConnections ("*");
 174                                 return;
 175                         }
 176 #endif
 177                         manager = (ConnectionManagementData) ConfigurationSettings.GetConfig (configKey);
 178                         if (manager != null) {
 179                                 defaultConnectionLimit = (int) manager.GetMaxConnections ("*");
 180                         }
 181 #endif
 182                 }
 183
 184                 // Constructors
 185                 private ServicePointManager ()
 186                 {
 187                 }
 188
 189                 // Properties
 190
 191                 [Obsolete ("Use ServerCertificateValidationCallback instead", false)]
 192                 public static ICertificatePolicy CertificatePolicy {
 193                         get { return policy; }
 194                         set { policy = value; }
 195                 }
 196
 197                 [MonoTODO("CRL checks not implemented")]
 198                 public static bool CheckCertificateRevocationList {
 199                         get { return _checkCRL; }
 200                         set { _checkCRL = false; }      // TODO - don't yet accept true
 201                 }
 202
 203                 public static int DefaultConnectionLimit {
 204                         get { return defaultConnectionLimit; }
 205                         set {
 206                                 if (value <= 0)
 207                                         throw new ArgumentOutOfRangeException ("value");
 208
 209                                 defaultConnectionLimit = value;
 210 #if !NET_2_1
 211                 if (manager != null)
 212                                         manager.Add ("*", defaultConnectionLimit);
 213 #endif
 214                         }
 215                 }
 216
 217                 static Exception GetMustImplement ()
 218                 {
 219                         return new NotImplementedException ();
 220                 }
 221
 222                 [MonoTODO]
 223                 public static int DnsRefreshTimeout
 224                 {
 225                         get {
 226                                 throw GetMustImplement ();
 227                         }
 228                         set {
 229                                 throw GetMustImplement ();
 230                         }
 231                 }
 232
 233                 [MonoTODO]
 234                 public static bool EnableDnsRoundRobin
 235                 {
 236                         get {
 237                                 throw GetMustImplement ();
 238                         }
 239                         set {
 240                                 throw GetMustImplement ();
 241                         }
 242                 }
 243
 244                 public static int MaxServicePointIdleTime {
 245                         get {
 246                                 return maxServicePointIdleTime;
 247                         }
 248                         set {
 249                                 if (value < -2 || value > Int32.MaxValue)
 250                                         throw new ArgumentOutOfRangeException ("value");
 251                                 maxServicePointIdleTime = value;
 252                         }
 253                 }
 254
 255                 public static int MaxServicePoints {
 256                         get {
 257                                 return maxServicePoints;
 258                         }
 259                         set {
 260                                 if (value < 0)
 261                                         throw new ArgumentException ("value");
 262
 263                                 maxServicePoints = value;
 264                                 RecycleServicePoints ();
 265                         }
 266                 }
 267
 268 #if NET_1_0
 269                 // we need it for SslClientStream
 270                 internal
 271 #else
 272                 public
 273 #endif
 274                 static SecurityProtocolType SecurityProtocol {
 275                         get { return _securityProtocol; }
 276                         set { _securityProtocol = value; }
 277                 }
 278
 279                 public static RemoteCertificateValidationCallback ServerCertificateValidationCallback
 280                 {
 281                         get {
 282                                 return server_cert_cb;
 283                         }
 284                         set {
 285                                 server_cert_cb = value;
 286                         }
 287                 }
 288
 289                 public static bool Expect100Continue {
 290                         get { return expectContinue; }
 291                         set { expectContinue = value; }
 292                 }
 293
 294                 public static bool UseNagleAlgorithm {
 295                         get { return useNagle; }
 296                         set { useNagle = value; }
 297                 }
 298
 299                 // Methods
 300                 public static void SetTcpKeepAlive (bool enabled, int keepAliveTime, int keepAliveInterval)
 301                 {
 302                         if (enabled) {
 303                                 if (keepAliveTime <= 0)
 304                                         throw new ArgumentOutOfRangeException ("keepAliveTime", "Must be greater than 0");
 305                                 if (keepAliveInterval <= 0)
 306                                         throw new ArgumentOutOfRangeException ("keepAliveInterval", "Must be greater than 0");
 307                         }
 308
 309                         tcp_keepalive = enabled;
 310                         tcp_keepalive_time = keepAliveTime;
 311                         tcp_keepalive_interval = keepAliveInterval;
 312                 }
 313
 314                 public static ServicePoint FindServicePoint (Uri address)
 315                 {
 316                         return FindServicePoint (address, GlobalProxySelection.Select);
 317                 }
 318
 319                 public static ServicePoint FindServicePoint (string uriString, IWebProxy proxy)
 320                 {
 321                         return FindServicePoint (new Uri(uriString), proxy);
 322                 }
 323
 324                 public static ServicePoint FindServicePoint (Uri address, IWebProxy proxy)
 325                 {
 326                         if (address == null)
 327                                 throw new ArgumentNullException ("address");
 328
 329                         if ((servicePoints.Count % 4) == 0)
 330                                 RecycleServicePoints ();
 331
 332                         var origAddress = new Uri (address.Scheme + "://" + address.Authority);
 333
 334                         bool usesProxy = false;
 335                         bool useConnect = false;
 336                         if (proxy != null && !proxy.IsBypassed(address)) {
 337                                 usesProxy = true;
 338                                 bool isSecure = address.Scheme == "https";
 339                                 address = proxy.GetProxy (address);
 340                                 if (address.Scheme != "http" && !isSecure)
 341                                         throw new NotSupportedException ("Proxy scheme not supported.");
 342
 343                                 if (isSecure && address.Scheme == "http")
 344                                         useConnect = true;
 345                         }
 346
 347                         address = new Uri (address.Scheme + "://" + address.Authority);
 348
 349                         ServicePoint sp = null;
 350                         SPKey key = new SPKey (origAddress, usesProxy ? address : null, useConnect);
 351                         lock (servicePoints) {
 352                                 sp = servicePoints [key] as ServicePoint;
 353                                 if (sp != null)
 354                                         return sp;
 355
 356                                 if (maxServicePoints > 0 && servicePoints.Count >= maxServicePoints)
 357                                         throw new InvalidOperationException ("maximum number of service points reached");
 358
 359                                 int limit;
 360 #if NET_2_1
 361                                 limit = defaultConnectionLimit;
 362 #else
 363                                 string addr = address.ToString ();
 364                                 limit = (int) manager.GetMaxConnections (addr);
 365 #endif
 366                                 sp = new ServicePoint (address, limit, maxServicePointIdleTime);
 367                                 sp.Expect100Continue = expectContinue;
 368                                 sp.UseNagleAlgorithm = useNagle;
 369                                 sp.UsesProxy = usesProxy;
 370                                 sp.UseConnect = useConnect;
 371                                 sp.SetTcpKeepAlive (tcp_keepalive, tcp_keepalive_time, tcp_keepalive_interval);
 372                                 servicePoints.Add (key, sp);
 373                         }
 374
 375                         return sp;
 376                 }
 377
 378                 // Internal Methods
 379
 380                 internal static void RecycleServicePoints ()
 381                 {
 382                         ArrayList toRemove = new ArrayList ();
 383                         lock (servicePoints) {
 384                                 IDictionaryEnumerator e = servicePoints.GetEnumerator ();
 385                                 while (e.MoveNext ()) {
 386                                         ServicePoint sp = (ServicePoint) e.Value;
 387                                         if (sp.AvailableForRecycling) {
 388                                                 toRemove.Add (e.Key);
 389                                         }
 390                                 }
 391
 392                                 for (int i = 0; i < toRemove.Count; i++)
 393                                         servicePoints.Remove (toRemove [i]);
 394
 395                                 if (maxServicePoints == 0 || servicePoints.Count <= maxServicePoints)
 396                                         return;
 397
 398                                 // get rid of the ones with the longest idle time
 399                                 SortedList list = new SortedList (servicePoints.Count);
 400                                 e = servicePoints.GetEnumerator ();
 401                                 while (e.MoveNext ()) {
 402                                         ServicePoint sp = (ServicePoint) e.Value;
 403                                         if (sp.CurrentConnections == 0) {
 404                                                 while (list.ContainsKey (sp.IdleSince))
 405                                                         sp.IdleSince = sp.IdleSince.AddMilliseconds (1);
 406                                                 list.Add (sp.IdleSince, sp.Address);
 407                                         }
 408                                 }
 409
 410                                 for (int i = 0; i < list.Count && servicePoints.Count > maxServicePoints; i++)
 411                                         servicePoints.Remove (list.GetByIndex (i));
 412                         }
 413                 }
 414 #if SECURITY_DEP
 415                 internal class ChainValidationHelper {
 416                         object sender;
 417                         string host;
 418                         RemoteCertificateValidationCallback cb;
 419
 420 #if !MONOTOUCH
 421                         static bool is_macosx = System.IO.File.Exists (OSX509Certificates.SecurityLibrary);
 422                         static X509RevocationMode revocation_mode;
 423
 424                         static ChainValidationHelper ()
 425                         {
 426                                 revocation_mode = X509RevocationMode.NoCheck;
 427                                 try {
 428                                         string str = Environment.GetEnvironmentVariable ("MONO_X509_REVOCATION_MODE");
 429                                         if (String.IsNullOrEmpty (str))
 430                                                 return;
 431                                         revocation_mode = (X509RevocationMode) Enum.Parse (typeof (X509RevocationMode), str, true);
 432                                 } catch {
 433                                 }
 434                         }
 435 #endif
 436
 437                         public ChainValidationHelper (object sender, string hostName)
 438                         {
 439                                 this.sender = sender;
 440                                 host = hostName;
 441                         }
 442
 443                         public RemoteCertificateValidationCallback ServerCertificateValidationCallback {
 444                                 get {
 445                                         if (cb == null)
 446                                                 cb = ServicePointManager.ServerCertificateValidationCallback;
 447                                         return cb;
 448                                 }
 449                                 set { cb = value; }
 450                         }
 451
 452                         // Used when the obsolete ICertificatePolicy is set to DefaultCertificatePolicy
 453                         // and the new ServerCertificateValidationCallback is not null
 454                         internal ValidationResult ValidateChain (MSX.X509CertificateCollection certs)
 455                         {
 456                                 // user_denied is true if the user callback is called and returns false
 457                                 bool user_denied = false;
 458                                 if (certs == null || certs.Count == 0)
 459                                         return null;
 460
 461                                 ICertificatePolicy policy = ServicePointManager.CertificatePolicy;
 462
 463                                 X509Certificate2 leaf = new X509Certificate2 (certs [0].RawData);
 464                                 int status11 = 0; // Error code passed to the obsolete ICertificatePolicy callback
 465                                 SslPolicyErrors errors = 0;
 466                                 X509Chain chain = null;
 467                                 bool result = false;
 468 #if MONOTOUCH
 469                                 // The X509Chain is not really usable with MonoTouch (since the decision is not based on this data)
 470                                 // However if someone wants to override the results (good or bad) from iOS then they will want all
 471                                 // the certificates that the server provided (which generally does not include the root) so, only
 472                                 // if there's a user callback, we'll create the X509Chain but won't build it
 473                                 // ref: https://bugzilla.xamarin.com/show_bug.cgi?id=7245
 474                                 if (ServerCertificateValidationCallback != null) {
 475 #endif
 476                                 chain = new X509Chain ();
 477                                 chain.ChainPolicy = new X509ChainPolicy ();
 478 #if !MONOTOUCH
 479                                 chain.ChainPolicy.RevocationMode = revocation_mode;
 480 #endif
 481                                 for (int i = 1; i < certs.Count; i++) {
 482                                         X509Certificate2 c2 = new X509Certificate2 (certs [i].RawData);
 483                                         chain.ChainPolicy.ExtraStore.Add (c2);
 484                                 }
 485 #if MONOTOUCH
 486                                 }
 487 #else
 488                                 try {
 489                                         if (!chain.Build (leaf))
 490                                                 errors |= GetErrorsFromChain (chain);
 491                                 } catch (Exception e) {
 492                                         Console.Error.WriteLine ("ERROR building certificate chain: {0}", e);
 493                                         Console.Error.WriteLine ("Please, report this problem to the Mono team");
 494                                         errors |= SslPolicyErrors.RemoteCertificateChainErrors;
 495                                 }
 496
 497                                 // for OSX and iOS we're using the native API to check for the SSL server policy and host names
 498                                 if (!is_macosx) {
 499                                         if (!CheckCertificateUsage (leaf)) {
 500                                                 errors |= SslPolicyErrors.RemoteCertificateChainErrors;
 501                                                 status11 = -2146762490; //CERT_E_PURPOSE 0x800B0106
 502                                         }
 503
 504                                         if (!CheckServerIdentity (certs [0], host)) {
 505                                                 errors |= SslPolicyErrors.RemoteCertificateNameMismatch;
 506                                                 status11 = -2146762481; // CERT_E_CN_NO_MATCH 0x800B010F
 507                                         }
 508                                 } else {
 509 #endif
 510                                         // Attempt to use OSX certificates
 511                                         // Ideally we should return the SecTrustResult
 512                                         OSX509Certificates.SecTrustResult trustResult = OSX509Certificates.SecTrustResult.Deny;
 513                                         try {
 514                                                 trustResult = OSX509Certificates.TrustEvaluateSsl (certs, host);
 515                                                 // We could use the other values of trustResult to pass this extra information
 516                                                 // to the .NET 2 callback for values like SecTrustResult.Confirm
 517                                                 result = (trustResult == OSX509Certificates.SecTrustResult.Proceed ||
 518                                                                   trustResult == OSX509Certificates.SecTrustResult.Unspecified);
 519                                         } catch {
 520                                                 // Ignore
 521                                         }
 522
 523                                         if (result) {
 524                                                 // TrustEvaluateSsl was successful so there's no trust error
 525                                                 // IOW we discard our own chain (since we trust OSX one instead)
 526                                                 errors = 0;
 527                                         } else {
 528                                                 // callback and DefaultCertificatePolicy needs this since 'result' is not specified
 529                                                 status11 = (int) trustResult;
 530                                                 errors |= SslPolicyErrors.RemoteCertificateChainErrors;
 531                                         }
 532 #if !MONOTOUCH
 533                                 }
 534 #endif
 535
 536 #if MONODROID && SECURITY_DEP
 537                                 result = AndroidPlatform.TrustEvaluateSsl (certs, sender, leaf, chain, errors);
 538                                 if (result) {
 539                                         // chain.Build() + GetErrorsFromChain() (above) will ALWAYS fail on
 540                                         // Android (there are no mozroots or preinstalled root certificates),
 541                                         // thus `errors` will ALWAYS have RemoteCertificateChainErrors.
 542                                         // Android just verified the chain; clear RemoteCertificateChainErrors.
 543                                         errors  &= ~SslPolicyErrors.RemoteCertificateChainErrors;
 544                                 }
 545 #endif
 546
 547                                 if (policy != null && (!(policy is DefaultCertificatePolicy) || cb == null)) {
 548                                         ServicePoint sp = null;
 549                                         HttpWebRequest req = sender as HttpWebRequest;
 550                                         if (req != null)
 551                                                 sp = req.ServicePointNoLock;
 552                                         if (status11 == 0 && errors != 0)
 553                                                 status11 = GetStatusFromChain (chain);
 554
 555                                         // pre 2.0 callback
 556                                         result = policy.CheckValidationResult (sp, leaf, req, status11);
 557                                         user_denied = !result && !(policy is DefaultCertificatePolicy);
 558                                 }
 559                                 // If there's a 2.0 callback, it takes precedence
 560                                 if (ServerCertificateValidationCallback != null) {
 561                                         result = ServerCertificateValidationCallback (sender, leaf, chain, errors);
 562                                         user_denied = !result;
 563                                 }
 564                                 return new ValidationResult (result, user_denied, status11);
 565                         }
 566
 567                         static int GetStatusFromChain (X509Chain chain)
 568                         {
 569                                 long result = 0;
 570                                 foreach (var status in chain.ChainStatus) {
 571                                         X509ChainStatusFlags flags = status.Status;
 572                                         if (flags == X509ChainStatusFlags.NoError)
 573                                                 continue;
 574
 575                                         // CERT_E_EXPIRED
 576                                         if ((flags & X509ChainStatusFlags.NotTimeValid) != 0) result = 0x800B0101;
 577                                         // CERT_E_VALIDITYPERIODNESTING
 578                                         else if ((flags & X509ChainStatusFlags.NotTimeNested) != 0) result = 0x800B0102;
 579                                         // CERT_E_REVOKED
 580                                         else if ((flags & X509ChainStatusFlags.Revoked) != 0) result = 0x800B010C;
 581                                         // TRUST_E_CERT_SIGNATURE
 582                                         else if ((flags & X509ChainStatusFlags.NotSignatureValid) != 0) result = 0x80096004;
 583                                         // CERT_E_WRONG_USAGE
 584                                         else if ((flags & X509ChainStatusFlags.NotValidForUsage) != 0) result = 0x800B0110;
 585                                         // CERT_E_UNTRUSTEDROOT
 586                                         else if ((flags & X509ChainStatusFlags.UntrustedRoot) != 0) result = 0x800B0109;
 587                                         // CRYPT_E_NO_REVOCATION_CHECK
 588                                         else if ((flags & X509ChainStatusFlags.RevocationStatusUnknown) != 0) result = 0x80092012;
 589                                         // CERT_E_CHAINING
 590                                         else if ((flags & X509ChainStatusFlags.Cyclic) != 0) result = 0x800B010A;
 591                                         // TRUST_E_FAIL - generic
 592                                         else if ((flags & X509ChainStatusFlags.InvalidExtension) != 0) result = 0x800B010B;
 593                                         // CERT_E_UNTRUSTEDROOT
 594                                         else if ((flags & X509ChainStatusFlags.InvalidPolicyConstraints) != 0) result = 0x800B010D;
 595                                         // TRUST_E_BASIC_CONSTRAINTS
 596                                         else if ((flags & X509ChainStatusFlags.InvalidBasicConstraints) != 0) result = 0x80096019;
 597                                         // CERT_E_INVALID_NAME
 598                                         else if ((flags & X509ChainStatusFlags.InvalidNameConstraints) != 0) result = 0x800B0114;
 599                                         // CERT_E_INVALID_NAME
 600                                         else if ((flags & X509ChainStatusFlags.HasNotSupportedNameConstraint) != 0) result = 0x800B0114;
 601                                         // CERT_E_INVALID_NAME
 602                                         else if ((flags & X509ChainStatusFlags.HasNotDefinedNameConstraint) != 0) result = 0x800B0114;
 603                                         // CERT_E_INVALID_NAME
 604                                         else if ((flags & X509ChainStatusFlags.HasNotPermittedNameConstraint) != 0) result = 0x800B0114;
 605                                         // CERT_E_INVALID_NAME
 606                                         else if ((flags & X509ChainStatusFlags.HasExcludedNameConstraint) != 0) result = 0x800B0114;
 607                                         // CERT_E_CHAINING
 608                                         else if ((flags & X509ChainStatusFlags.PartialChain) != 0) result = 0x800B010A;
 609                                         // CERT_E_EXPIRED
 610                                         else if ((flags & X509ChainStatusFlags.CtlNotTimeValid) != 0) result = 0x800B0101;
 611                                         // TRUST_E_CERT_SIGNATURE
 612                                         else if ((flags & X509ChainStatusFlags.CtlNotSignatureValid) != 0) result = 0x80096004;
 613                                         // CERT_E_WRONG_USAGE
 614                                         else if ((flags & X509ChainStatusFlags.CtlNotValidForUsage) != 0) result = 0x800B0110;
 615                                         // CRYPT_E_NO_REVOCATION_CHECK
 616                                         else if ((flags & X509ChainStatusFlags.OfflineRevocation) != 0) result = 0x80092012;
 617                                         // CERT_E_ISSUERCHAINING
 618                                         else if ((flags & X509ChainStatusFlags.NoIssuanceChainPolicy) != 0) result = 0x800B0107;
 619                                         else result = 0x800B010B; // TRUST_E_FAIL - generic
 620
 621                                         break; // Exit the loop on the first error
 622                                 }
 623                                 return (int) result;
 624                         }
 625 #if !MONOTOUCH
 626                         static SslPolicyErrors GetErrorsFromChain (X509Chain chain)
 627                         {
 628                                 SslPolicyErrors errors = SslPolicyErrors.None;
 629                                 foreach (var status in chain.ChainStatus) {
 630                                         if (status.Status == X509ChainStatusFlags.NoError)
 631                                                 continue;
 632                                         errors |= SslPolicyErrors.RemoteCertificateChainErrors;
 633                                         break;
 634                                 }
 635                                 return errors;
 636                         }
 637
 638                         static X509KeyUsageFlags s_flags = X509KeyUsageFlags.DigitalSignature  |
 639                                                         X509KeyUsageFlags.KeyAgreement |
 640                                                         X509KeyUsageFlags.KeyEncipherment;
 641                         // Adapted to System 2.0+ from TlsServerCertificate.cs
 642                         //------------------------------
 643                         // Note: this method only works for RSA certificates
 644                         // DH certificates requires some changes - does anyone use one ?
 645                         static bool CheckCertificateUsage (X509Certificate2 cert)
 646                         {
 647                                 try {
 648                                         // certificate extensions are required for this
 649                                         // we "must" accept older certificates without proofs
 650                                         if (cert.Version < 3)
 651                                                 return true;
 652
 653                                         X509KeyUsageExtension kux = (cert.Extensions ["2.5.29.15"] as X509KeyUsageExtension);
 654                                         X509EnhancedKeyUsageExtension eku = (cert.Extensions ["2.5.29.37"] as X509EnhancedKeyUsageExtension);
 655                                         if (kux != null && eku != null) {
 656                                                 // RFC3280 states that when both KeyUsageExtension and
 657                                                 // ExtendedKeyUsageExtension are present then BOTH should
 658                                                 // be valid
 659                                                 if ((kux.KeyUsages & s_flags) == 0)
 660                                                         return false;
 661                                                 return eku.EnhancedKeyUsages ["1.3.6.1.5.5.7.3.1"] != null ||
 662                                                         eku.EnhancedKeyUsages ["2.16.840.1.113730.4.1"] != null;
 663                                         } else if (kux != null) {
 664                                                 return ((kux.KeyUsages & s_flags) != 0);
 665                                         } else if (eku != null) {
 666                                                 // Server Authentication (1.3.6.1.5.5.7.3.1) or
 667                                                 // Netscape Server Gated Crypto (2.16.840.1.113730.4)
 668                                                 return eku.EnhancedKeyUsages ["1.3.6.1.5.5.7.3.1"] != null ||
 669                                                         eku.EnhancedKeyUsages ["2.16.840.1.113730.4.1"] != null;
 670                                         }
 671
 672                                         // last chance - try with older (deprecated) Netscape extensions
 673                                         X509Extension ext = cert.Extensions ["2.16.840.1.113730.1.1"];
 674                                         if (ext != null) {
 675                                                 string text = ext.NetscapeCertType (false);
 676                                                 return text.IndexOf ("SSL Server Authentication", StringComparison.Ordinal) != -1;
 677                                         }
 678                                         return true;
 679                                 } catch (Exception e) {
 680                                         Console.Error.WriteLine ("ERROR processing certificate: {0}", e);
 681                                         Console.Error.WriteLine ("Please, report this problem to the Mono team");
 682                                         return false;
 683                                 }
 684                         }
 685
 686                         // RFC2818 - HTTP Over TLS, Section 3.1
 687                         // http://www.ietf.org/rfc/rfc2818.txt
 688                         //
 689                         // 1.   if present MUST use subjectAltName dNSName as identity
 690                         // 1.1.         if multiples entries a match of any one is acceptable
 691                         // 1.2.         wildcard * is acceptable
 692                         // 2.   URI may be an IP address -> subjectAltName.iPAddress
 693                         // 2.1.         exact match is required
 694                         // 3.   Use of the most specific Common Name (CN=) in the Subject
 695                         // 3.1          Existing practice but DEPRECATED
 696                         static bool CheckServerIdentity (MSX.X509Certificate cert, string targetHost)
 697                         {
 698                                 try {
 699                                         MSX.X509Extension ext = cert.Extensions ["2.5.29.17"];
 700                                         // 1. subjectAltName
 701                                         if (ext != null) {
 702                                                 SubjectAltNameExtension subjectAltName = new SubjectAltNameExtension (ext);
 703                                                 // 1.1 - multiple dNSName
 704                                                 foreach (string dns in subjectAltName.DNSNames) {
 705                                                         // 1.2 TODO - wildcard support
 706                                                         if (Match (targetHost, dns))
 707                                                                 return true;
 708                                                 }
 709                                                 // 2. ipAddress
 710                                                 foreach (string ip in subjectAltName.IPAddresses) {
 711                                                         // 2.1. Exact match required
 712                                                         if (ip == targetHost)
 713                                                                 return true;
 714                                                 }
 715                                         }
 716                                         // 3. Common Name (CN=)
 717                                         return CheckDomainName (cert.SubjectName, targetHost);
 718                                 } catch (Exception e) {
 719                                         Console.Error.WriteLine ("ERROR processing certificate: {0}", e);
 720                                         Console.Error.WriteLine ("Please, report this problem to the Mono team");
 721                                         return false;
 722                                 }
 723                         }
 724
 725                         static bool CheckDomainName (string subjectName, string targetHost)
 726                         {
 727                                 string  domainName = String.Empty;
 728                                 Regex search = new Regex(@"CN\s*=\s*([^,]*)");
 729                                 MatchCollection elements = search.Matches(subjectName);
 730                                 if (elements.Count == 1) {
 731                                         if (elements[0].Success)
 732                                                 domainName = elements[0].Groups[1].Value.ToString();
 733                                 }
 734
 735                                 return Match (targetHost, domainName);
 736                         }
 737
 738                         // ensure the pattern is valid wrt to RFC2595 and RFC2818
 739                         // http://www.ietf.org/rfc/rfc2595.txt
 740                         // http://www.ietf.org/rfc/rfc2818.txt
 741                         static bool Match (string hostname, string pattern)
 742                         {
 743                                 // check if this is a pattern
 744                                 int index = pattern.IndexOf ('*');
 745                                 if (index == -1) {
 746                                         // not a pattern, do a direct case-insensitive comparison
 747                                         return (String.Compare (hostname, pattern, true, CultureInfo.InvariantCulture) == 0);
 748                                 }
 749
 750                                 // check pattern validity
 751                                 // A "*" wildcard character MAY be used as the left-most name component in the certificate.
 752
 753                                 // unless this is the last char (valid)
 754                                 if (index != pattern.Length - 1) {
 755                                         // then the next char must be a dot .'.
 756                                         if (pattern [index + 1] != '.')
 757                                                 return false;
 758                                 }
 759
 760                                 // only one (A) wildcard is supported
 761                                 int i2 = pattern.IndexOf ('*', index + 1);
 762                                 if (i2 != -1)
 763                                         return false;
 764
 765                                 // match the end of the pattern
 766                                 string end = pattern.Substring (index + 1);
 767                                 int length = hostname.Length - end.Length;
 768                                 // no point to check a pattern that is longer than the hostname
 769                                 if (length <= 0)
 770                                         return false;
 771
 772                                 if (String.Compare (hostname, length, end, 0, end.Length, true, CultureInfo.InvariantCulture) != 0)
 773                                         return false;
 774
 775                                 // special case, we start with the wildcard
 776                                 if (index == 0) {
 777                                         // ensure we hostname non-matched part (start) doesn't contain a dot
 778                                         int i3 = hostname.IndexOf ('.');
 779                                         return ((i3 == -1) || (i3 >= (hostname.Length - end.Length)));
 780                                 }
 781
 782                                 // match the start of the pattern
 783                                 string start = pattern.Substring (0, index);
 784                                 return (String.Compare (hostname, 0, start, 0, start.Length, true, CultureInfo.InvariantCulture) == 0);
 785                         }
 786 #endif
 787                 }
 788 #endif
 789         }
 790 }
 791