mcs/class/System/Mono.Net.Security/LegacySslStream.cs

   1 //
   2 // System.Net.Security.SslStream.cs
   3 //
   4 // Authors:
   5 //      Tim Coleman (tim@timcoleman.com)
   6 //      Atsushi Enomoto (atsushi@ximian.com)
   7 //      Marek Safar (marek.safar@gmail.com)
   8 //
   9 // Copyright (C) Tim Coleman, 2004
  10 // (c) 2004,2007 Novell, Inc. (http://www.novell.com)
  11 // Copyright 2011 Xamarin Inc.
  12 //
  13
  14 //
  15 // Permission is hereby granted, free of charge, to any person obtaining
  16 // a copy of this software and associated documentation files (the
  17 // "Software"), to deal in the Software without restriction, including
  18 // without limitation the rights to use, copy, modify, merge, publish,
  19 // distribute, sublicense, and/or sell copies of the Software, and to
  20 // permit persons to whom the Software is furnished to do so, subject to
  21 // the following conditions:
  22 //
  23 // The above copyright notice and this permission notice shall be
  24 // included in all copies or substantial portions of the Software.
  25 //
  26 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  27 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  28 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  29 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  30 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  31 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  32 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  33 //
  34
  35 #if SECURITY_DEP
  36
  37 #if MONO_X509_ALIAS
  38 extern alias PrebuiltSystem;
  39 #endif
  40 #if MONO_SECURITY_ALIAS
  41 extern alias MonoSecurity;
  42 #endif
  43
  44 #if MONO_SECURITY_ALIAS
  45 using MonoCipherAlgorithmType = MonoSecurity::Mono.Security.Protocol.Tls.CipherAlgorithmType;
  46 using MonoHashAlgorithmType = MonoSecurity::Mono.Security.Protocol.Tls.HashAlgorithmType;
  47 using MonoExchangeAlgorithmType = MonoSecurity::Mono.Security.Protocol.Tls.ExchangeAlgorithmType;
  48 using MonoSecurityProtocolType = MonoSecurity::Mono.Security.Protocol.Tls.SecurityProtocolType;
  49 using MonoSecurity::Mono.Security.Protocol.Tls;
  50 using MonoSecurity::Mono.Security.Interface;
  51 #else
  52 using MonoCipherAlgorithmType = Mono.Security.Protocol.Tls.CipherAlgorithmType;
  53 using MonoHashAlgorithmType = Mono.Security.Protocol.Tls.HashAlgorithmType;
  54 using MonoExchangeAlgorithmType = Mono.Security.Protocol.Tls.ExchangeAlgorithmType;
  55 using MonoSecurityProtocolType = Mono.Security.Protocol.Tls.SecurityProtocolType;
  56 using Mono.Security.Protocol.Tls;
  57 using Mono.Security.Interface;
  58 #endif
  59 #if MONO_X509_ALIAS
  60 using X509CertificateCollection = PrebuiltSystem::System.Security.Cryptography.X509Certificates.X509CertificateCollection;
  61 #endif
  62
  63 using CipherAlgorithmType = System.Security.Authentication.CipherAlgorithmType;
  64 using HashAlgorithmType = System.Security.Authentication.HashAlgorithmType;
  65 using ExchangeAlgorithmType = System.Security.Authentication.ExchangeAlgorithmType;
  66
  67 using System;
  68 using System.IO;
  69 using System.Net;
  70 using System.Net.Security;
  71 using System.Security.Authentication;
  72 using System.Security.Cryptography.X509Certificates;
  73 using System.Security.Principal;
  74 using System.Security.Cryptography;
  75
  76 using System.Threading.Tasks;
  77
  78 namespace Mono.Net.Security
  79 {
  80         [MonoTODO ("Non-X509Certificate2 certificate is not supported")]
  81         internal class LegacySslStream : AuthenticatedStream, IMonoSslStream
  82         {
  83                 #region Fields
  84
  85                 SslStreamBase ssl_stream;
  86                 MonoTlsSettings settings;
  87                 ICertificateValidator certificateValidator;
  88
  89                 #endregion // Fields
  90
  91                 #region Constructors
  92
  93                 public LegacySslStream (Stream innerStream)
  94                         : this (innerStream, false)
  95                 {
  96                 }
  97
  98                 public LegacySslStream (Stream innerStream, bool leaveInnerStreamOpen)
  99                         : base (innerStream, leaveInnerStreamOpen)
 100                 {
 101                 }
 102
 103                 public LegacySslStream (Stream innerStream, bool leaveInnerStreamOpen, MonoTlsSettings settings)
 104                         : base (innerStream, leaveInnerStreamOpen)
 105                 {
 106                         this.settings = settings;
 107                         this.certificateValidator = settings.CertificateValidator;
 108                 }
 109                 #endregion // Constructors
 110
 111                 #region Properties
 112
 113                 public override bool CanRead {
 114                         get { return InnerStream.CanRead; }
 115                 }
 116
 117                 public override bool CanSeek {
 118                         get { return InnerStream.CanSeek; }
 119                 }
 120
 121                 public override bool CanTimeout {
 122                         get { return InnerStream.CanTimeout; }
 123                 }
 124
 125                 public override bool CanWrite {
 126                         get { return InnerStream.CanWrite; }
 127                 }
 128
 129                 public override long Length {
 130                         get { return InnerStream.Length; }
 131                 }
 132
 133                 public override long Position {
 134                         get { return InnerStream.Position; }
 135                         set {
 136                                 throw new NotSupportedException ("This stream does not support seek operations");
 137                         }
 138                 }
 139
 140                 // AuthenticatedStream overrides
 141
 142                 public override bool IsAuthenticated {
 143                         get { return ssl_stream != null; }
 144                 }
 145
 146                 public override bool IsEncrypted {
 147                         get { return IsAuthenticated; }
 148                 }
 149
 150                 public override bool IsMutuallyAuthenticated {
 151                         get { return IsAuthenticated && (IsServer ? RemoteCertificate != null : LocalCertificate != null); }
 152                 }
 153
 154                 public override bool IsServer {
 155                         get { return ssl_stream is SslServerStream; }
 156                 }
 157
 158                 public override bool IsSigned {
 159                         get { return IsAuthenticated; }
 160                 }
 161
 162                 public override int ReadTimeout {
 163                         get { return InnerStream.ReadTimeout; }
 164                         set { InnerStream.ReadTimeout = value; }
 165                 }
 166
 167                 public override int WriteTimeout {
 168                         get { return InnerStream.WriteTimeout; }
 169                         set { InnerStream.WriteTimeout = value; }
 170                 }
 171
 172                 // SslStream
 173
 174                 public virtual bool CheckCertRevocationStatus {
 175                         get {
 176                                 if (!IsAuthenticated)
 177                                         return false;
 178
 179                                 return ssl_stream.CheckCertRevocationStatus;
 180                         }
 181                 }
 182
 183                 public virtual CipherAlgorithmType CipherAlgorithm  {
 184                         get {
 185                                 CheckConnectionAuthenticated ();
 186
 187                                 switch (ssl_stream.CipherAlgorithm) {
 188                                 case MonoCipherAlgorithmType.Des:
 189                                         return CipherAlgorithmType.Des;
 190                                 case MonoCipherAlgorithmType.None:
 191                                         return CipherAlgorithmType.None;
 192                                 case MonoCipherAlgorithmType.Rc2:
 193                                         return CipherAlgorithmType.Rc2;
 194                                 case MonoCipherAlgorithmType.Rc4:
 195                                         return CipherAlgorithmType.Rc4;
 196                                 case MonoCipherAlgorithmType.SkipJack:
 197                                         break;
 198                                 case MonoCipherAlgorithmType.TripleDes:
 199                                         return CipherAlgorithmType.TripleDes;
 200                                 case MonoCipherAlgorithmType.Rijndael:
 201                                         switch (ssl_stream.CipherStrength) {
 202                                         case 128:
 203                                                 return CipherAlgorithmType.Aes128;
 204                                         case 192:
 205                                                 return CipherAlgorithmType.Aes192;
 206                                         case 256:
 207                                                 return CipherAlgorithmType.Aes256;
 208                                         }
 209                                         break;
 210                                 }
 211
 212                                 throw new InvalidOperationException ("Not supported cipher algorithm is in use. It is likely a bug in SslStream.");
 213                         }
 214                 }
 215
 216                 public virtual int CipherStrength  {
 217                         get {
 218                                 CheckConnectionAuthenticated ();
 219
 220                                 return ssl_stream.CipherStrength;
 221                         }
 222                 }
 223
 224                 public virtual HashAlgorithmType HashAlgorithm  {
 225                         get {
 226                                 CheckConnectionAuthenticated ();
 227
 228                                 switch (ssl_stream.HashAlgorithm) {
 229                                 case MonoHashAlgorithmType.Md5:
 230                                         return HashAlgorithmType.Md5;
 231                                 case MonoHashAlgorithmType.None:
 232                                         return HashAlgorithmType.None;
 233                                 case MonoHashAlgorithmType.Sha1:
 234                                         return HashAlgorithmType.Sha1;
 235                                 }
 236
 237                                 throw new InvalidOperationException ("Not supported hash algorithm is in use. It is likely a bug in SslStream.");
 238                         }
 239                 }
 240
 241                 public virtual int HashStrength  {
 242                         get {
 243                                 CheckConnectionAuthenticated ();
 244
 245                                 return ssl_stream.HashStrength;
 246                         }
 247                 }
 248
 249                 public virtual ExchangeAlgorithmType KeyExchangeAlgorithm {
 250                         get {
 251                                 CheckConnectionAuthenticated ();
 252
 253                                 switch (ssl_stream.KeyExchangeAlgorithm) {
 254                                 case MonoExchangeAlgorithmType.DiffieHellman:
 255                                         return ExchangeAlgorithmType.DiffieHellman;
 256                                 case MonoExchangeAlgorithmType.Fortezza:
 257                                         break;
 258                                 case MonoExchangeAlgorithmType.None:
 259                                         return ExchangeAlgorithmType.None;
 260                                 case MonoExchangeAlgorithmType.RsaKeyX:
 261                                         return ExchangeAlgorithmType.RsaKeyX;
 262                                 case MonoExchangeAlgorithmType.RsaSign:
 263                                         return ExchangeAlgorithmType.RsaSign;
 264                                 }
 265
 266                                 throw new InvalidOperationException ("Not supported exchange algorithm is in use. It is likely a bug in SslStream.");
 267                         }
 268                 }
 269
 270                 public virtual int KeyExchangeStrength {
 271                         get {
 272                                 CheckConnectionAuthenticated ();
 273
 274                                 return ssl_stream.KeyExchangeStrength;
 275                         }
 276                 }
 277
 278                 X509Certificate IMonoSslStream.InternalLocalCertificate {
 279                         get {
 280                                 return IsServer ? ssl_stream.ServerCertificate : ((SslClientStream) ssl_stream).SelectedClientCertificate;
 281                         }
 282                 }
 283
 284                 public virtual X509Certificate LocalCertificate {
 285                         get {
 286                                 CheckConnectionAuthenticated ();
 287
 288                                 return IsServer ? ssl_stream.ServerCertificate : ((SslClientStream) ssl_stream).SelectedClientCertificate;
 289                         }
 290                 }
 291
 292                 public virtual X509Certificate RemoteCertificate {
 293                         get {
 294                                 CheckConnectionAuthenticated ();
 295                                 return !IsServer ? ssl_stream.ServerCertificate : ((SslServerStream) ssl_stream).ClientCertificate;
 296                         }
 297                 }
 298
 299                 public virtual SslProtocols SslProtocol {
 300                         get {
 301                                 CheckConnectionAuthenticated ();
 302
 303                                 switch (ssl_stream.SecurityProtocol) {
 304                                 case MonoSecurityProtocolType.Default:
 305                                         return SslProtocols.Default;
 306                                 case MonoSecurityProtocolType.Ssl2:
 307                                         return SslProtocols.Ssl2;
 308                                 case MonoSecurityProtocolType.Ssl3:
 309                                         return SslProtocols.Ssl3;
 310                                 case MonoSecurityProtocolType.Tls:
 311                                         return SslProtocols.Tls;
 312                                 }
 313
 314                                 throw new InvalidOperationException ("Not supported SSL/TLS protocol is in use. It is likely a bug in SslStream.");
 315                         }
 316                 }
 317
 318                 #endregion // Properties
 319
 320                 #region Methods
 321
 322 /*
 323                 AsymmetricAlgorithm GetPrivateKey (X509Certificate cert, string targetHost)
 324                 {
 325                         // FIXME: what can I do for non-X509Certificate2 ?
 326                         X509Certificate2 cert2 = cert as X509Certificate2;
 327                         return cert2 != null ? cert2.PrivateKey : null;
 328                 }
 329 */
 330                 X509Certificate OnCertificateSelection (X509CertificateCollection clientCerts, X509Certificate serverCert, string targetHost, X509CertificateCollection serverRequestedCerts)
 331                 {
 332                         string [] acceptableIssuers = new string [serverRequestedCerts != null ? serverRequestedCerts.Count : 0];
 333                         for (int i = 0; i < acceptableIssuers.Length; i++)
 334                                 acceptableIssuers [i] = serverRequestedCerts [i].GetIssuerName ();
 335                         return certificateValidator.SelectClientCertificate (targetHost, clientCerts, serverCert, acceptableIssuers);
 336                 }
 337
 338                 public virtual IAsyncResult BeginAuthenticateAsClient (string targetHost, AsyncCallback asyncCallback, object asyncState)
 339                 {
 340                         return BeginAuthenticateAsClient (targetHost, new X509CertificateCollection (), SslProtocols.Tls, false, asyncCallback, asyncState);
 341                 }
 342
 343                 public virtual IAsyncResult BeginAuthenticateAsClient (string targetHost, X509CertificateCollection clientCertificates, SslProtocols enabledSslProtocols, bool checkCertificateRevocation, AsyncCallback asyncCallback, object asyncState)
 344                 {
 345                         if (IsAuthenticated)
 346                                 throw new InvalidOperationException ("This SslStream is already authenticated");
 347
 348                         SslClientStream s = new SslClientStream (InnerStream, targetHost, !LeaveInnerStreamOpen, GetMonoSslProtocol (enabledSslProtocols), clientCertificates);
 349                         s.CheckCertRevocationStatus = checkCertificateRevocation;
 350
 351                         // Due to the Mono.Security internal, it cannot reuse
 352                         // the delegated argument, as Mono.Security creates
 353                         // another instance of X509Certificate which lacks
 354                         // private key but is filled the private key via this
 355                         // delegate.
 356                         s.PrivateKeyCertSelectionDelegate = delegate (X509Certificate cert, string host) {
 357                                 string hash = cert.GetCertHashString ();
 358                                 // ... so, we cannot use the delegate argument.
 359                                 foreach (X509Certificate cc in clientCertificates) {
 360                                         if (cc.GetCertHashString () != hash)
 361                                                 continue;
 362                                         X509Certificate2 cert2 = cc as X509Certificate2;
 363                                         cert2 = cert2 ?? new X509Certificate2 (cc);
 364                                         return cert2.PrivateKey;
 365                                 }
 366                                 return null;
 367                         };
 368
 369                         // Even if validation_callback is null this allows us to verify requests where the user
 370                         // does not provide a verification callback but attempts to authenticate with the website
 371                         // as a client (see https://bugzilla.xamarin.com/show_bug.cgi?id=18962 for an example)
 372                         s.ServerCertValidation2 += (certs) => ((ChainValidationHelper)certificateValidator).ValidateChain (targetHost, certs);
 373                         s.ClientCertSelectionDelegate = OnCertificateSelection;
 374
 375                         ssl_stream = s;
 376
 377                         return BeginWrite (new byte [0], 0, 0, asyncCallback, asyncState);
 378                 }
 379
 380                 public override IAsyncResult BeginRead (byte[] buffer, int offset, int count, AsyncCallback asyncCallback, object asyncState)
 381                 {
 382                         CheckConnectionAuthenticated ();
 383
 384                         return ssl_stream.BeginRead (buffer, offset, count, asyncCallback, asyncState);
 385                 }
 386
 387                 public virtual IAsyncResult BeginAuthenticateAsServer (X509Certificate serverCertificate, AsyncCallback asyncCallback, object asyncState)
 388                 {
 389                         return BeginAuthenticateAsServer (serverCertificate, false, SslProtocols.Tls, false, asyncCallback, asyncState);
 390                 }
 391
 392                 public virtual IAsyncResult BeginAuthenticateAsServer (X509Certificate serverCertificate, bool clientCertificateRequired, SslProtocols enabledSslProtocols, bool checkCertificateRevocation, AsyncCallback asyncCallback, object asyncState)
 393                 {
 394                         if (IsAuthenticated)
 395                                 throw new InvalidOperationException ("This SslStream is already authenticated");
 396
 397                         SslServerStream s = new SslServerStream (InnerStream, serverCertificate, clientCertificateRequired, !LeaveInnerStreamOpen, GetMonoSslProtocol (enabledSslProtocols));
 398                         s.CheckCertRevocationStatus = checkCertificateRevocation;
 399                         // Due to the Mono.Security internal, it cannot reuse
 400                         // the delegated argument, as Mono.Security creates
 401                         // another instance of X509Certificate which lacks
 402                         // private key but is filled the private key via this
 403                         // delegate.
 404                         s.PrivateKeyCertSelectionDelegate = delegate (X509Certificate cert, string targetHost) {
 405                                 // ... so, we cannot use the delegate argument.
 406                                 X509Certificate2 cert2 = serverCertificate as X509Certificate2 ?? new X509Certificate2 (serverCertificate);
 407                                 return cert2 != null ? cert2.PrivateKey : null;
 408                         };
 409
 410                         s.ClientCertValidationDelegate = delegate (X509Certificate cert, int[] certErrors) {
 411                                 var errors = certErrors.Length > 0 ? MonoSslPolicyErrors.RemoteCertificateChainErrors : MonoSslPolicyErrors.None;
 412                                 return ((ChainValidationHelper)certificateValidator).ValidateClientCertificate (cert, errors);
 413                         };
 414
 415                         ssl_stream = s;
 416
 417                         return BeginWrite (new byte[0], 0, 0, asyncCallback, asyncState);
 418                 }
 419
 420                 MonoSecurityProtocolType GetMonoSslProtocol (SslProtocols ms)
 421                 {
 422                         switch (ms) {
 423                         case SslProtocols.Ssl2:
 424                                 return MonoSecurityProtocolType.Ssl2;
 425                         case SslProtocols.Ssl3:
 426                                 return MonoSecurityProtocolType.Ssl3;
 427                         case SslProtocols.Tls:
 428                                 return MonoSecurityProtocolType.Tls;
 429                         default:
 430                                 return MonoSecurityProtocolType.Default;
 431                         }
 432                 }
 433
 434                 public override IAsyncResult BeginWrite (byte[] buffer, int offset, int count, AsyncCallback asyncCallback, object asyncState)
 435                 {
 436                         CheckConnectionAuthenticated ();
 437
 438                         return ssl_stream.BeginWrite (buffer, offset, count, asyncCallback, asyncState);
 439                 }
 440
 441                 public virtual void AuthenticateAsClient (string targetHost)
 442                 {
 443                         AuthenticateAsClient (targetHost, new X509CertificateCollection (), SslProtocols.Tls, false);
 444                 }
 445
 446                 public virtual void AuthenticateAsClient (string targetHost, X509CertificateCollection clientCertificates, SslProtocols enabledSslProtocols, bool checkCertificateRevocation)
 447                 {
 448                         EndAuthenticateAsClient (BeginAuthenticateAsClient (
 449                                 targetHost, clientCertificates, enabledSslProtocols, checkCertificateRevocation, null, null));
 450                 }
 451
 452                 public virtual void AuthenticateAsServer (X509Certificate serverCertificate)
 453                 {
 454                         AuthenticateAsServer (serverCertificate, false, SslProtocols.Tls, false);
 455                 }
 456
 457                 public virtual void AuthenticateAsServer (X509Certificate serverCertificate, bool clientCertificateRequired, SslProtocols enabledSslProtocols, bool checkCertificateRevocation)
 458                 {
 459                         EndAuthenticateAsServer (BeginAuthenticateAsServer (
 460                                 serverCertificate, clientCertificateRequired, enabledSslProtocols, checkCertificateRevocation, null, null));
 461                 }
 462
 463                 protected override void Dispose (bool disposing)
 464                 {
 465                         if (disposing) {
 466                                 if (ssl_stream != null)
 467                                         ssl_stream.Dispose ();
 468                                 ssl_stream = null;
 469                         }
 470                         base.Dispose (disposing);
 471                 }
 472
 473                 public virtual void EndAuthenticateAsClient (IAsyncResult asyncResult)
 474                 {
 475                         CheckConnectionAuthenticated ();
 476
 477                         if (CanRead)
 478                                 ssl_stream.EndRead (asyncResult);
 479                         else
 480                                 ssl_stream.EndWrite (asyncResult);
 481                 }
 482
 483                 public virtual void EndAuthenticateAsServer (IAsyncResult asyncResult)
 484                 {
 485                         CheckConnectionAuthenticated ();
 486
 487                         if (CanRead)
 488                                 ssl_stream.EndRead (asyncResult);
 489                         else
 490                                 ssl_stream.EndWrite (asyncResult);
 491                 }
 492
 493                 public override int EndRead (IAsyncResult asyncResult)
 494                 {
 495                         CheckConnectionAuthenticated ();
 496
 497                         return ssl_stream.EndRead (asyncResult);
 498                 }
 499
 500                 public override void EndWrite (IAsyncResult asyncResult)
 501                 {
 502                         CheckConnectionAuthenticated ();
 503
 504                         ssl_stream.EndWrite (asyncResult);
 505                 }
 506
 507                 public override void Flush ()
 508                 {
 509                         CheckConnectionAuthenticated ();
 510
 511                         InnerStream.Flush ();
 512                 }
 513
 514                 public override int Read (byte[] buffer, int offset, int count)
 515                 {
 516                         return EndRead (BeginRead (buffer, offset, count, null, null));
 517                 }
 518
 519                 public override long Seek (long offset, SeekOrigin origin)
 520                 {
 521                         throw new NotSupportedException ("This stream does not support seek operations");
 522                 }
 523
 524                 public override void SetLength (long value)
 525                 {
 526                         InnerStream.SetLength (value);
 527                 }
 528
 529                 public override void Write (byte[] buffer, int offset, int count)
 530                 {
 531                         EndWrite (BeginWrite (buffer, offset, count, null, null));
 532                 }
 533
 534                 public void Write (byte[] buffer)
 535                 {
 536                         Write (buffer, 0, buffer.Length);
 537                 }
 538
 539                 void CheckConnectionAuthenticated ()
 540                 {
 541                         if (!IsAuthenticated)
 542                                 throw new InvalidOperationException ("This operation is invalid until it is successfully authenticated");
 543                 }
 544
 545                 public virtual Task AuthenticateAsClientAsync (string targetHost)
 546                 {
 547                         return Task.Factory.FromAsync (BeginAuthenticateAsClient, EndAuthenticateAsClient, targetHost, null);
 548                 }
 549
 550                 public virtual Task AuthenticateAsClientAsync (string targetHost, X509CertificateCollection clientCertificates, SslProtocols enabledSslProtocols, bool checkCertificateRevocation)
 551                 {
 552                         var t = Tuple.Create (targetHost, clientCertificates, enabledSslProtocols, checkCertificateRevocation, this);
 553
 554                         return Task.Factory.FromAsync ((callback, state) => {
 555                                 var d = (Tuple<string, X509CertificateCollection, SslProtocols, bool, LegacySslStream>) state;
 556                                 return d.Item5.BeginAuthenticateAsClient (d.Item1, d.Item2, d.Item3, d.Item4, callback, null);
 557                         }, EndAuthenticateAsClient, t);
 558                 }
 559
 560                 public virtual Task AuthenticateAsServerAsync (X509Certificate serverCertificate)
 561                 {
 562                         return Task.Factory.FromAsync (BeginAuthenticateAsServer, EndAuthenticateAsServer, serverCertificate, null);
 563                 }
 564
 565                 public virtual Task AuthenticateAsServerAsync (X509Certificate serverCertificate, bool clientCertificateRequired, SslProtocols enabledSslProtocols, bool checkCertificateRevocation)
 566                 {
 567                         var t = Tuple.Create (serverCertificate, clientCertificateRequired, enabledSslProtocols, checkCertificateRevocation, this);
 568
 569                         return Task.Factory.FromAsync ((callback, state) => {
 570                                 var d = (Tuple<X509Certificate, bool, SslProtocols, bool, LegacySslStream>) state;
 571                                 return d.Item5.BeginAuthenticateAsServer (d.Item1, d.Item2, d.Item3, d.Item4, callback, null);
 572                         }, EndAuthenticateAsServer, t);
 573                 }
 574
 575                 #endregion // Methods
 576
 577                 #region IMonoSslStream
 578
 579                 AuthenticatedStream IMonoSslStream.AuthenticatedStream {
 580                         get { return this; }
 581                 }
 582
 583                 TransportContext IMonoSslStream.TransportContext {
 584                         get { throw new NotSupportedException (); }
 585                 }
 586
 587                 #endregion
 588         }
 589 }
 590
 591 #endif