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 using System;
  33 using System.Collections;
  34 using System.Collections.Specialized;
  35 using System.Configuration;
  36 using System.Net.Configuration;
  37 using System.Security.Cryptography.X509Certificates;
  38
  39 using System.Globalization;
  40 using System.Net.Security;
  41 #if SECURITY_DEP
  42 using System.Text.RegularExpressions;
  43 using Mono.Security;
  44 using Mono.Security.Cryptography;
  45 using Mono.Security.X509.Extensions;
  46 using Mono.Security.Protocol.Tls;
  47 using MSX = Mono.Security.X509;
  48 #endif
  49
  50 //
  51 // notes:
  52 // A service point manager manages service points (duh!).
  53 // A service point maintains a list of connections (per scheme + authority).
  54 // According to HttpWebRequest.ConnectionGroupName each connection group
  55 // creates additional connections. therefor, a service point has a hashtable
  56 // of connection groups where each value is a list of connections.
  57 //
  58 // when we need to make an HttpWebRequest, we need to do the following:
  59 // 1. find service point, given Uri and Proxy
  60 // 2. find connection group, given service point and group name
  61 // 3. find free connection in connection group, or create one (if ok due to limits)
  62 // 4. lease connection
  63 // 5. execute request
  64 // 6. when finished, return connection
  65 //
  66
  67
  68 namespace System.Net
  69 {
  70 #if MOONLIGHT
  71         internal class ServicePointManager {
  72 #else
  73         public class ServicePointManager {
  74 #endif
  75                 class SPKey {
  76                         Uri uri; // schema/host/port
  77                         bool use_connect;
  78
  79                         public SPKey (Uri uri, bool use_connect) {
  80                                 this.uri = uri;
  81                                 this.use_connect = use_connect;
  82                         }
  83
  84                         public Uri Uri {
  85                                 get { return uri; }
  86                         }
  87
  88                         public bool UseConnect {
  89                                 get { return use_connect; }
  90                         }
  91
  92                         public override int GetHashCode () {
  93                                 return uri.GetHashCode () + ((use_connect) ? 1 : 0);
  94                         }
  95
  96                         public override bool Equals (object obj) {
  97                                 SPKey other = obj as SPKey;
  98                                 if (obj == null) {
  99                                         return false;
 100                                 }
 101
 102                                 return (uri.Equals (other.uri) && other.use_connect == use_connect);
 103                         }
 104                 }
 105
 106                 private static HybridDictionary servicePoints = new HybridDictionary ();
 107
 108                 // Static properties
 109
 110                 private static ICertificatePolicy policy = new DefaultCertificatePolicy ();
 111                 private static int defaultConnectionLimit = DefaultPersistentConnectionLimit;
 112                 private static int maxServicePointIdleTime = 900000; // 15 minutes
 113                 private static int maxServicePoints = 0;
 114                 private static bool _checkCRL = false;
 115                 private static SecurityProtocolType _securityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls;
 116
 117 #if NET_1_1
 118 #if TARGET_JVM
 119                 static bool expectContinue = false;
 120 #else
 121                 static bool expectContinue = true;
 122 #endif
 123                 static bool useNagle;
 124 #endif
 125                 static RemoteCertificateValidationCallback server_cert_cb;
 126                 static bool tcp_keepalive;
 127                 static int tcp_keepalive_time;
 128                 static int tcp_keepalive_interval;
 129
 130                 // Fields
 131
 132                 public const int DefaultNonPersistentConnectionLimit = 4;
 133                 public const int DefaultPersistentConnectionLimit = 2;
 134
 135 #if !NET_2_1
 136                 const string configKey = "system.net/connectionManagement";
 137                 static ConnectionManagementData manager;
 138 #endif
 139
 140                 static ServicePointManager ()
 141                 {
 142 #if !NET_2_1
 143 #if NET_2_0 && CONFIGURATION_DEP
 144                         object cfg = ConfigurationManager.GetSection (configKey);
 145                         ConnectionManagementSection s = cfg as ConnectionManagementSection;
 146                         if (s != null) {
 147                                 manager = new ConnectionManagementData (null);
 148                                 foreach (ConnectionManagementElement e in s.ConnectionManagement)
 149                                         manager.Add (e.Address, e.MaxConnection);
 150
 151                                 defaultConnectionLimit = (int) manager.GetMaxConnections ("*");
 152                                 return;
 153                         }
 154 #endif
 155                         manager = (ConnectionManagementData) ConfigurationSettings.GetConfig (configKey);
 156                         if (manager != null) {
 157                                 defaultConnectionLimit = (int) manager.GetMaxConnections ("*");
 158                         }
 159 #endif
 160                 }
 161
 162                 // Constructors
 163                 private ServicePointManager ()
 164                 {
 165                 }
 166
 167                 // Properties
 168
 169 #if NET_2_0
 170                 [Obsolete ("Use ServerCertificateValidationCallback instead", false)]
 171 #endif
 172                 public static ICertificatePolicy CertificatePolicy {
 173                         get { return policy; }
 174                         set { policy = value; }
 175                 }
 176
 177 #if NET_1_0
 178                 // we need it for SslClientStream
 179                 internal
 180 #else
 181                 [MonoTODO("CRL checks not implemented")]
 182                 public
 183 #endif
 184                 static bool CheckCertificateRevocationList {
 185                         get { return _checkCRL; }
 186                         set { _checkCRL = false; }      // TODO - don't yet accept true
 187                 }
 188
 189                 public static int DefaultConnectionLimit {
 190                         get { return defaultConnectionLimit; }
 191                         set {
 192                                 if (value <= 0)
 193                                         throw new ArgumentOutOfRangeException ("value");
 194
 195                                 defaultConnectionLimit = value;
 196                         }
 197                 }
 198
 199 #if NET_2_0
 200                 static Exception GetMustImplement ()
 201                 {
 202                         return new NotImplementedException ();
 203                 }
 204
 205                 [MonoTODO]
 206                 public static int DnsRefreshTimeout
 207                 {
 208                         get {
 209                                 throw GetMustImplement ();
 210                         }
 211                         set {
 212                                 throw GetMustImplement ();
 213                         }
 214                 }
 215
 216                 [MonoTODO]
 217                 public static bool EnableDnsRoundRobin
 218                 {
 219                         get {
 220                                 throw GetMustImplement ();
 221                         }
 222                         set {
 223                                 throw GetMustImplement ();
 224                         }
 225                 }
 226 #endif
 227
 228                 public static int MaxServicePointIdleTime {
 229                         get {
 230                                 return maxServicePointIdleTime;
 231                         }
 232                         set {
 233                                 if (value < -2 || value > Int32.MaxValue)
 234                                         throw new ArgumentOutOfRangeException ("value");
 235                                 maxServicePointIdleTime = value;
 236                         }
 237                 }
 238
 239                 public static int MaxServicePoints {
 240                         get {
 241                                 return maxServicePoints;
 242                         }
 243                         set {
 244                                 if (value < 0)
 245                                         throw new ArgumentException ("value");
 246
 247                                 maxServicePoints = value;
 248                                 RecycleServicePoints ();
 249                         }
 250                 }
 251
 252 #if NET_1_0
 253                 // we need it for SslClientStream
 254                 internal
 255 #else
 256                 public
 257 #endif
 258                 static SecurityProtocolType SecurityProtocol {
 259                         get { return _securityProtocol; }
 260                         set { _securityProtocol = value; }
 261                 }
 262
 263                 public static RemoteCertificateValidationCallback ServerCertificateValidationCallback
 264                 {
 265                         get {
 266                                 return server_cert_cb;
 267                         }
 268                         set {
 269                                 server_cert_cb = value;
 270                         }
 271                 }
 272
 273 #if NET_1_1
 274                 public static bool Expect100Continue {
 275                         get { return expectContinue; }
 276                         set { expectContinue = value; }
 277                 }
 278
 279                 public static bool UseNagleAlgorithm {
 280                         get { return useNagle; }
 281                         set { useNagle = value; }
 282                 }
 283 #endif
 284                 // Methods
 285                 public static void SetTcpKeepAlive (bool enabled, int keepAliveTime, int keepAliveInterval)
 286                 {
 287                         if (enabled) {
 288                                 if (keepAliveTime <= 0)
 289                                         throw new ArgumentOutOfRangeException ("keepAliveTime", "Must be greater than 0");
 290                                 if (keepAliveInterval <= 0)
 291                                         throw new ArgumentOutOfRangeException ("keepAliveInterval", "Must be greater than 0");
 292                         }
 293
 294                         tcp_keepalive = enabled;
 295                         tcp_keepalive_time = keepAliveTime;
 296                         tcp_keepalive_interval = keepAliveInterval;
 297                 }
 298
 299                 public static ServicePoint FindServicePoint (Uri address)
 300                 {
 301                         return FindServicePoint (address, GlobalProxySelection.Select);
 302                 }
 303
 304                 public static ServicePoint FindServicePoint (string uriString, IWebProxy proxy)
 305                 {
 306                         return FindServicePoint (new Uri(uriString), proxy);
 307                 }
 308
 309                 public static ServicePoint FindServicePoint (Uri address, IWebProxy proxy)
 310                 {
 311                         if (address == null)
 312                                 throw new ArgumentNullException ("address");
 313
 314                         RecycleServicePoints ();
 315
 316                         bool usesProxy = false;
 317                         bool useConnect = false;
 318                         if (proxy != null && !proxy.IsBypassed(address)) {
 319                                 usesProxy = true;
 320                                 bool isSecure = address.Scheme == "https";
 321                                 address = proxy.GetProxy (address);
 322                                 if (address.Scheme != "http" && !isSecure)
 323                                         throw new NotSupportedException ("Proxy scheme not supported.");
 324
 325                                 if (isSecure && address.Scheme == "http")
 326                                         useConnect = true;
 327                         }
 328
 329                         address = new Uri (address.Scheme + "://" + address.Authority);
 330
 331                         ServicePoint sp = null;
 332                         lock (servicePoints) {
 333                                 SPKey key = new SPKey (address, useConnect);
 334                                 sp = servicePoints [key] as ServicePoint;
 335                                 if (sp != null)
 336                                         return sp;
 337
 338                                 if (maxServicePoints > 0 && servicePoints.Count >= maxServicePoints)
 339                                         throw new InvalidOperationException ("maximum number of service points reached");
 340
 341                                 string addr = address.ToString ();
 342 #if NET_2_1
 343                                 int limit = defaultConnectionLimit;
 344 #else
 345                                 int limit = (int) manager.GetMaxConnections (addr);
 346 #endif
 347                                 sp = new ServicePoint (address, limit, maxServicePointIdleTime);
 348                                 sp.Expect100Continue = expectContinue;
 349                                 sp.UseNagleAlgorithm = useNagle;
 350                                 sp.UsesProxy = usesProxy;
 351                                 sp.UseConnect = useConnect;
 352                                 sp.SetTcpKeepAlive (tcp_keepalive, tcp_keepalive_time, tcp_keepalive_interval);
 353                                 servicePoints.Add (key, sp);
 354                         }
 355
 356                         return sp;
 357                 }
 358
 359                 // Internal Methods
 360
 361                 internal static void RecycleServicePoints ()
 362                 {
 363                         ArrayList toRemove = new ArrayList ();
 364                         lock (servicePoints) {
 365                                 IDictionaryEnumerator e = servicePoints.GetEnumerator ();
 366                                 while (e.MoveNext ()) {
 367                                         ServicePoint sp = (ServicePoint) e.Value;
 368                                         if (sp.AvailableForRecycling) {
 369                                                 toRemove.Add (e.Key);
 370                                         }
 371                                 }
 372
 373                                 for (int i = 0; i < toRemove.Count; i++)
 374                                         servicePoints.Remove (toRemove [i]);
 375
 376                                 if (maxServicePoints == 0 || servicePoints.Count <= maxServicePoints)
 377                                         return;
 378
 379                                 // get rid of the ones with the longest idle time
 380                                 SortedList list = new SortedList (servicePoints.Count);
 381                                 e = servicePoints.GetEnumerator ();
 382                                 while (e.MoveNext ()) {
 383                                         ServicePoint sp = (ServicePoint) e.Value;
 384                                         if (sp.CurrentConnections == 0) {
 385                                                 while (list.ContainsKey (sp.IdleSince))
 386                                                         sp.IdleSince = sp.IdleSince.AddMilliseconds (1);
 387                                                 list.Add (sp.IdleSince, sp.Address);
 388                                         }
 389                                 }
 390
 391                                 for (int i = 0; i < list.Count && servicePoints.Count > maxServicePoints; i++)
 392                                         servicePoints.Remove (list.GetByIndex (i));
 393                         }
 394                 }
 395 #if MOONLIGHT && SECURITY_DEP
 396                 internal class ChainValidationHelper {
 397                         object sender;
 398
 399                         public ChainValidationHelper (object sender)
 400                         {
 401                                 this.sender = sender;
 402                         }
 403
 404                         // no need to check certificates since we are either
 405                         // (a) loading from the site of origin (and we accepted its certificate to load from it)
 406                         // (b) loading from a cross-domain site and we downloaded the policy file using the browser stack
 407                         //     i.e. the certificate was accepted (or the policy would not be valid)
 408                         internal ValidationResult ValidateChain (Mono.Security.X509.X509CertificateCollection certs)
 409                         {
 410                                 return new ValidationResult (true, false, 0);
 411                         }
 412                 }
 413 #elif NET_2_0 && SECURITY_DEP
 414                 internal class ChainValidationHelper {
 415                         object sender;
 416                         string host;
 417                         static bool is_macosx = System.IO.File.Exists (MSX.OSX509Certificates.SecurityLibrary);
 418                         static X509RevocationMode revocation_mode;
 419
 420 #if MONODROID
 421                         static readonly Converter<Mono.Security.X509.X509CertificateCollection, bool> monodroidCallback;
 422 #endif
 423
 424                         static ChainValidationHelper ()
 425                         {
 426 #if MONODROID
 427                                 monodroidCallback = (Converter<Mono.Security.X509.X509CertificateCollection, bool>)
 428                                         Delegate.CreateDelegate (typeof(Converter<Mono.Security.X509.X509CertificateCollection, bool>),
 429                                                         Type.GetType ("Android.Runtime.AndroidEnvironment, Mono.Android", true)
 430                                                         .GetMethod ("TrustEvaluateSsl",
 431                                                                 System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic));
 432 #endif
 433 #if !MONOTOUCH
 434                                 revocation_mode = X509RevocationMode.NoCheck;
 435                                 try {
 436                                         string str = Environment.GetEnvironmentVariable ("MONO_X509_REVOCATION_MODE");
 437                                         if (String.IsNullOrEmpty (str))
 438                                                 return;
 439                                         revocation_mode = (X509RevocationMode) Enum.Parse (typeof (X509RevocationMode), str, true);
 440                                 } catch {
 441                                 }
 442 #endif
 443                         }
 444
 445                         public ChainValidationHelper (object sender)
 446                         {
 447                                 this.sender = sender;
 448                         }
 449
 450                         public string Host {
 451                                 get {
 452                                         if (host == null && sender is HttpWebRequest)
 453                                                 host = ((HttpWebRequest) sender).Address.Host;
 454                                         return host;
 455                                 }
 456
 457                                 set { host = value; }
 458                         }
 459
 460                         // Used when the obsolete ICertificatePolicy is set to DefaultCertificatePolicy
 461                         // and the new ServerCertificateValidationCallback is not null
 462                         internal ValidationResult ValidateChain (Mono.Security.X509.X509CertificateCollection certs)
 463                         {
 464                                 // user_denied is true if the user callback is called and returns false
 465                                 bool user_denied = false;
 466                                 if (certs == null || certs.Count == 0)
 467                                         return null;
 468
 469                                 ICertificatePolicy policy = ServicePointManager.CertificatePolicy;
 470                                 RemoteCertificateValidationCallback cb = ServicePointManager.ServerCertificateValidationCallback;
 471
 472                                 X509Certificate2 leaf = new X509Certificate2 (certs [0].RawData);
 473                                 int status11 = 0; // Error code passed to the obsolete ICertificatePolicy callback
 474                                 SslPolicyErrors errors = 0;
 475                                 X509Chain chain = null;
 476 #if !MONOTOUCH
 477                                 chain = new X509Chain ();
 478                                 chain.ChainPolicy = new X509ChainPolicy ();
 479                                 chain.ChainPolicy.RevocationMode = revocation_mode;
 480                                 for (int i = 1; i < certs.Count; i++) {
 481                                         X509Certificate2 c2 = new X509Certificate2 (certs [i].RawData);
 482                                         chain.ChainPolicy.ExtraStore.Add (c2);
 483                                 }
 484
 485                                 try {
 486                                         if (!chain.Build (leaf))
 487                                                 errors |= GetErrorsFromChain (chain);
 488                                 } catch (Exception e) {
 489                                         Console.Error.WriteLine ("ERROR building certificate chain: {0}", e);
 490                                         Console.Error.WriteLine ("Please, report this problem to the Mono team");
 491                                         errors |= SslPolicyErrors.RemoteCertificateChainErrors;
 492                                 }
 493 #endif
 494                                 if (!CheckCertificateUsage (leaf)) {
 495                                         errors |= SslPolicyErrors.RemoteCertificateChainErrors;
 496                                         status11 = -2146762490; //CERT_E_PURPOSE 0x800B0106
 497                                 }
 498
 499                                 if (!CheckServerIdentity (certs [0], Host)) {
 500                                         errors |= SslPolicyErrors.RemoteCertificateNameMismatch;
 501                                         status11 = -2146762481; // CERT_E_CN_NO_MATCH 0x800B010F
 502                                 }
 503
 504                                 bool result = false;
 505                                 // No certificate root found means no mozroots or monotouch
 506 #if !MONOTOUCH
 507                                 if (is_macosx) {
 508 #endif
 509                                         // Attempt to use OSX certificates
 510                                         // Ideally we should return the SecTrustResult
 511                                         MSX.OSX509Certificates.SecTrustResult trustResult;
 512                                         try {
 513                                                 trustResult = MSX.OSX509Certificates.TrustEvaluateSsl (certs);
 514                                                 // We could use the other values of trustResult to pass this extra information
 515                                                 // to the .NET 2 callback for values like SecTrustResult.Confirm
 516                                                 result = (trustResult == MSX.OSX509Certificates.SecTrustResult.Proceed ||
 517                                                                   trustResult == MSX.OSX509Certificates.SecTrustResult.Unspecified);
 518
 519                                         } catch {
 520                                                 // Ignore
 521                                         }
 522                                         // Clear error status if the OS told us to trust the certificate
 523                                         if (result) {
 524                                                 status11 = 0;
 525                                                 errors = 0;
 526                                         }
 527 #if !MONOTOUCH
 528                                 }
 529 #endif
 530
 531 #if MONODROID
 532                                 result = monodroidCallback (certs);
 533                                 if (result) {
 534                                         status11 = 0;
 535                                         errors = 0;
 536                                 }
 537 #endif
 538
 539                                 if (policy != null && (!(policy is DefaultCertificatePolicy) || cb == null)) {
 540                                         ServicePoint sp = null;
 541                                         HttpWebRequest req = sender as HttpWebRequest;
 542                                         if (req != null)
 543                                                 sp = req.ServicePointNoLock;
 544                                         if (status11 == 0 && errors != 0)
 545                                                 status11 = GetStatusFromChain (chain);
 546
 547                                         // pre 2.0 callback
 548                                         result = policy.CheckValidationResult (sp, leaf, req, status11);
 549                                         user_denied = !result && !(policy is DefaultCertificatePolicy);
 550                                 }
 551                                 // If there's a 2.0 callback, it takes precedence
 552                                 if (cb != null) {
 553                                         result = cb (sender, leaf, chain, errors);
 554                                         user_denied = !result;
 555                                 }
 556                                 return new ValidationResult (result, user_denied, status11);
 557                         }
 558
 559                         static int GetStatusFromChain (X509Chain chain)
 560                         {
 561                                 long result = 0;
 562                                 foreach (var status in chain.ChainStatus) {
 563                                         X509ChainStatusFlags flags = status.Status;
 564                                         if (flags == X509ChainStatusFlags.NoError)
 565                                                 continue;
 566
 567                                         // CERT_E_EXPIRED
 568                                         if ((flags & X509ChainStatusFlags.NotTimeValid) != 0) result = 0x800B0101;
 569                                         // CERT_E_VALIDITYPERIODNESTING
 570                                         else if ((flags & X509ChainStatusFlags.NotTimeNested) != 0) result = 0x800B0102;
 571                                         // CERT_E_REVOKED
 572                                         else if ((flags & X509ChainStatusFlags.Revoked) != 0) result = 0x800B010C;
 573                                         // TRUST_E_CERT_SIGNATURE
 574                                         else if ((flags & X509ChainStatusFlags.NotSignatureValid) != 0) result = 0x80096004;
 575                                         // CERT_E_WRONG_USAGE
 576                                         else if ((flags & X509ChainStatusFlags.NotValidForUsage) != 0) result = 0x800B0110;
 577                                         // CERT_E_UNTRUSTEDROOT
 578                                         else if ((flags & X509ChainStatusFlags.UntrustedRoot) != 0) result = 0x800B0109;
 579                                         // CRYPT_E_NO_REVOCATION_CHECK
 580                                         else if ((flags & X509ChainStatusFlags.RevocationStatusUnknown) != 0) result = 0x80092012;
 581                                         // CERT_E_CHAINING
 582                                         else if ((flags & X509ChainStatusFlags.Cyclic) != 0) result = 0x800B010A;
 583                                         // TRUST_E_FAIL - generic
 584                                         else if ((flags & X509ChainStatusFlags.InvalidExtension) != 0) result = 0x800B010B;
 585                                         // CERT_E_UNTRUSTEDROOT
 586                                         else if ((flags & X509ChainStatusFlags.InvalidPolicyConstraints) != 0) result = 0x800B010D;
 587                                         // TRUST_E_BASIC_CONSTRAINTS
 588                                         else if ((flags & X509ChainStatusFlags.InvalidBasicConstraints) != 0) result = 0x80096019;
 589                                         // CERT_E_INVALID_NAME
 590                                         else if ((flags & X509ChainStatusFlags.InvalidNameConstraints) != 0) result = 0x800B0114;
 591                                         // CERT_E_INVALID_NAME
 592                                         else if ((flags & X509ChainStatusFlags.HasNotSupportedNameConstraint) != 0) result = 0x800B0114;
 593                                         // CERT_E_INVALID_NAME
 594                                         else if ((flags & X509ChainStatusFlags.HasNotDefinedNameConstraint) != 0) result = 0x800B0114;
 595                                         // CERT_E_INVALID_NAME
 596                                         else if ((flags & X509ChainStatusFlags.HasNotPermittedNameConstraint) != 0) result = 0x800B0114;
 597                                         // CERT_E_INVALID_NAME
 598                                         else if ((flags & X509ChainStatusFlags.HasExcludedNameConstraint) != 0) result = 0x800B0114;
 599                                         // CERT_E_CHAINING
 600                                         else if ((flags & X509ChainStatusFlags.PartialChain) != 0) result = 0x800B010A;
 601                                         // CERT_E_EXPIRED
 602                                         else if ((flags & X509ChainStatusFlags.CtlNotTimeValid) != 0) result = 0x800B0101;
 603                                         // TRUST_E_CERT_SIGNATURE
 604                                         else if ((flags & X509ChainStatusFlags.CtlNotSignatureValid) != 0) result = 0x80096004;
 605                                         // CERT_E_WRONG_USAGE
 606                                         else if ((flags & X509ChainStatusFlags.CtlNotValidForUsage) != 0) result = 0x800B0110;
 607                                         // CRYPT_E_NO_REVOCATION_CHECK
 608                                         else if ((flags & X509ChainStatusFlags.OfflineRevocation) != 0) result = 0x80092012;
 609                                         // CERT_E_ISSUERCHAINING
 610                                         else if ((flags & X509ChainStatusFlags.NoIssuanceChainPolicy) != 0) result = 0x800B0107;
 611                                         else result = 0x800B010B; // TRUST_E_FAIL - generic
 612
 613                                         break; // Exit the loop on the first error
 614                                 }
 615                                 return (int) result;
 616                         }
 617
 618                         static SslPolicyErrors GetErrorsFromChain (X509Chain chain)
 619                         {
 620                                 SslPolicyErrors errors = SslPolicyErrors.None;
 621                                 foreach (var status in chain.ChainStatus) {
 622                                         if (status.Status == X509ChainStatusFlags.NoError)
 623                                                 continue;
 624                                         errors |= SslPolicyErrors.RemoteCertificateChainErrors;
 625                                         break;
 626                                 }
 627                                 return errors;
 628                         }
 629
 630                         static X509KeyUsageFlags s_flags = X509KeyUsageFlags.DigitalSignature  |
 631                                                         X509KeyUsageFlags.KeyAgreement |
 632                                                         X509KeyUsageFlags.KeyEncipherment;
 633                         // Adapted to System 2.0+ from TlsServerCertificate.cs
 634                         //------------------------------
 635                         // Note: this method only works for RSA certificates
 636                         // DH certificates requires some changes - does anyone use one ?
 637                         static bool CheckCertificateUsage (X509Certificate2 cert)
 638                         {
 639                                 try {
 640                                         // certificate extensions are required for this
 641                                         // we "must" accept older certificates without proofs
 642                                         if (cert.Version < 3)
 643                                                 return true;
 644
 645                                         X509KeyUsageExtension kux = (cert.Extensions ["2.5.29.15"] as X509KeyUsageExtension);
 646                                         X509EnhancedKeyUsageExtension eku = (cert.Extensions ["2.5.29.37"] as X509EnhancedKeyUsageExtension);
 647                                         if (kux != null && eku != null) {
 648                                                 // RFC3280 states that when both KeyUsageExtension and
 649                                                 // ExtendedKeyUsageExtension are present then BOTH should
 650                                                 // be valid
 651                                                 if ((kux.KeyUsages & s_flags) == 0)
 652                                                         return false;
 653                                                 return eku.EnhancedKeyUsages ["1.3.6.1.5.5.7.3.1"] != null ||
 654                                                         eku.EnhancedKeyUsages ["2.16.840.1.113730.4.1"] != null;
 655                                         } else if (kux != null) {
 656                                                 return ((kux.KeyUsages & s_flags) != 0);
 657                                         } else if (eku != null) {
 658                                                 // Server Authentication (1.3.6.1.5.5.7.3.1) or
 659                                                 // Netscape Server Gated Crypto (2.16.840.1.113730.4)
 660                                                 return eku.EnhancedKeyUsages ["1.3.6.1.5.5.7.3.1"] != null ||
 661                                                         eku.EnhancedKeyUsages ["2.16.840.1.113730.4.1"] != null;
 662                                         }
 663
 664                                         // last chance - try with older (deprecated) Netscape extensions
 665                                         X509Extension ext = cert.Extensions ["2.16.840.1.113730.1.1"];
 666                                         if (ext != null) {
 667                                                 string text = ext.NetscapeCertType (false);
 668                                                 return text.IndexOf ("SSL Server Authentication", StringComparison.Ordinal) != -1;
 669                                         }
 670                                         return true;
 671                                 } catch (Exception e) {
 672                                         Console.Error.WriteLine ("ERROR processing certificate: {0}", e);
 673                                         Console.Error.WriteLine ("Please, report this problem to the Mono team");
 674                                         return false;
 675                                 }
 676                         }
 677
 678                         // RFC2818 - HTTP Over TLS, Section 3.1
 679                         // http://www.ietf.org/rfc/rfc2818.txt
 680                         //
 681                         // 1.   if present MUST use subjectAltName dNSName as identity
 682                         // 1.1.         if multiples entries a match of any one is acceptable
 683                         // 1.2.         wildcard * is acceptable
 684                         // 2.   URI may be an IP address -> subjectAltName.iPAddress
 685                         // 2.1.         exact match is required
 686                         // 3.   Use of the most specific Common Name (CN=) in the Subject
 687                         // 3.1          Existing practice but DEPRECATED
 688                         static bool CheckServerIdentity (Mono.Security.X509.X509Certificate cert, string targetHost)
 689                         {
 690                                 try {
 691                                         Mono.Security.X509.X509Extension ext = cert.Extensions ["2.5.29.17"];
 692                                         // 1. subjectAltName
 693                                         if (ext != null) {
 694                                                 SubjectAltNameExtension subjectAltName = new SubjectAltNameExtension (ext);
 695                                                 // 1.1 - multiple dNSName
 696                                                 foreach (string dns in subjectAltName.DNSNames) {
 697                                                         // 1.2 TODO - wildcard support
 698                                                         if (Match (targetHost, dns))
 699                                                                 return true;
 700                                                 }
 701                                                 // 2. ipAddress
 702                                                 foreach (string ip in subjectAltName.IPAddresses) {
 703                                                         // 2.1. Exact match required
 704                                                         if (ip == targetHost)
 705                                                                 return true;
 706                                                 }
 707                                         }
 708                                         // 3. Common Name (CN=)
 709                                         return CheckDomainName (cert.SubjectName, targetHost);
 710                                 } catch (Exception e) {
 711                                         Console.Error.WriteLine ("ERROR processing certificate: {0}", e);
 712                                         Console.Error.WriteLine ("Please, report this problem to the Mono team");
 713                                         return false;
 714                                 }
 715                         }
 716
 717                         static bool CheckDomainName (string subjectName, string targetHost)
 718                         {
 719                                 string  domainName = String.Empty;
 720                                 Regex search = new Regex(@"CN\s*=\s*([^,]*)");
 721                                 MatchCollection elements = search.Matches(subjectName);
 722                                 if (elements.Count == 1) {
 723                                         if (elements[0].Success)
 724                                                 domainName = elements[0].Groups[1].Value.ToString();
 725                                 }
 726
 727                                 return Match (targetHost, domainName);
 728                         }
 729
 730                         // ensure the pattern is valid wrt to RFC2595 and RFC2818
 731                         // http://www.ietf.org/rfc/rfc2595.txt
 732                         // http://www.ietf.org/rfc/rfc2818.txt
 733                         static bool Match (string hostname, string pattern)
 734                         {
 735                                 // check if this is a pattern
 736                                 int index = pattern.IndexOf ('*');
 737                                 if (index == -1) {
 738                                         // not a pattern, do a direct case-insensitive comparison
 739                                         return (String.Compare (hostname, pattern, true, CultureInfo.InvariantCulture) == 0);
 740                                 }
 741
 742                                 // check pattern validity
 743                                 // A "*" wildcard character MAY be used as the left-most name component in the certificate.
 744
 745                                 // unless this is the last char (valid)
 746                                 if (index != pattern.Length - 1) {
 747                                         // then the next char must be a dot .'.
 748                                         if (pattern [index + 1] != '.')
 749                                                 return false;
 750                                 }
 751
 752                                 // only one (A) wildcard is supported
 753                                 int i2 = pattern.IndexOf ('*', index + 1);
 754                                 if (i2 != -1)
 755                                         return false;
 756
 757                                 // match the end of the pattern
 758                                 string end = pattern.Substring (index + 1);
 759                                 int length = hostname.Length - end.Length;
 760                                 // no point to check a pattern that is longer than the hostname
 761                                 if (length <= 0)
 762                                         return false;
 763
 764                                 if (String.Compare (hostname, length, end, 0, end.Length, true, CultureInfo.InvariantCulture) != 0)
 765                                         return false;
 766
 767                                 // special case, we start with the wildcard
 768                                 if (index == 0) {
 769                                         // ensure we hostname non-matched part (start) doesn't contain a dot
 770                                         int i3 = hostname.IndexOf ('.');
 771                                         return ((i3 == -1) || (i3 >= (hostname.Length - end.Length)));
 772                                 }
 773
 774                                 // match the start of the pattern
 775                                 string start = pattern.Substring (0, index);
 776                                 return (String.Compare (hostname, 0, start, 0, start.Length, true, CultureInfo.InvariantCulture) == 0);
 777                         }
 778                 }
 779 #endif
 780         }
 781 }
 782