mcs/class/System/System.Net.Mail/SmtpClient.cs

   1 //
   2 // System.Net.Mail.SmtpClient.cs
   3 //
   4 // Author:
   5 //      Tim Coleman (tim@timcoleman.com)
   6 //
   7 // Copyright (C) Tim Coleman, 2004
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 #if SECURITY_DEP
  32
  33 #if MONOTOUCH || MONODROID
  34 using System.Security.Cryptography.X509Certificates;
  35 #else
  36 extern alias PrebuiltSystem;
  37 using X509CertificateCollection = PrebuiltSystem::System.Security.Cryptography.X509Certificates.X509CertificateCollection;
  38 using System.Security.Cryptography.X509Certificates;
  39 #endif
  40
  41 #endif
  42
  43 using System;
  44 using System.Collections.Generic;
  45 using System.ComponentModel;
  46 using System.Globalization;
  47 using System.IO;
  48 using System.Net;
  49 using System.Net.Mime;
  50 using System.Net.Sockets;
  51 using System.Text;
  52 using System.Threading;
  53 using System.Reflection;
  54 using System.Net.Configuration;
  55 using System.Configuration;
  56 using System.Net.Security;
  57 using System.Security.Authentication;
  58 #if NET_4_5
  59 using System.Threading.Tasks;
  60 #endif
  61
  62 namespace System.Net.Mail {
  63         public class SmtpClient
  64 #if NET_4_0
  65         : IDisposable
  66 #endif
  67         {
  68                 #region Fields
  69
  70                 string host;
  71                 int port;
  72                 int timeout = 100000;
  73                 ICredentialsByHost credentials;
  74                 string pickupDirectoryLocation;
  75                 SmtpDeliveryMethod deliveryMethod;
  76                 bool enableSsl;
  77 #if SECURITY_DEP
  78                 X509CertificateCollection clientCertificates;
  79 #endif
  80
  81                 TcpClient client;
  82                 Stream stream;
  83                 StreamWriter writer;
  84                 StreamReader reader;
  85                 int boundaryIndex;
  86                 MailAddress defaultFrom;
  87
  88                 MailMessage messageInProcess;
  89
  90                 BackgroundWorker worker;
  91                 object user_async_state;
  92
  93                 [Flags]
  94                 enum AuthMechs {
  95                         None        = 0,
  96                         Login       = 0x01,
  97                         Plain       = 0x02,
  98                 }
  99
 100                 class CancellationException : Exception
 101                 {
 102                 }
 103
 104                 AuthMechs authMechs;
 105                 Mutex mutex = new Mutex ();
 106
 107                 #endregion // Fields
 108
 109                 #region Constructors
 110
 111                 public SmtpClient ()
 112                         : this (null, 0)
 113                 {
 114                 }
 115
 116                 public SmtpClient (string host)
 117                         : this (host, 0)
 118                 {
 119                 }
 120
 121                 public SmtpClient (string host, int port) {
 122 #if CONFIGURATION_DEP
 123                         SmtpSection cfg = (SmtpSection) ConfigurationManager.GetSection ("system.net/mailSettings/smtp");
 124
 125                         if (cfg != null) {
 126                                 this.host = cfg.Network.Host;
 127                                 this.port = cfg.Network.Port;
 128 #if NET_4_0
 129                                 this.enableSsl = cfg.Network.EnableSsl;
 130 #endif
 131                                 TargetName = cfg.Network.TargetName;
 132                                 if (this.TargetName == null)
 133                                         TargetName = "SMTPSVC/" + (host != null ? host : "");
 134
 135
 136                                 if (cfg.Network.UserName != null) {
 137                                         string password = String.Empty;
 138
 139                                         if (cfg.Network.Password != null)
 140                                                 password = cfg.Network.Password;
 141
 142                                         Credentials = new CCredentialsByHost (cfg.Network.UserName, password);
 143                                 }
 144
 145                                 if (!String.IsNullOrEmpty (cfg.From))
 146                                         defaultFrom = new MailAddress (cfg.From);
 147                         }
 148 #else
 149                         // Just to eliminate the warning, this codepath does not end up in production.
 150                         defaultFrom = null;
 151 #endif
 152
 153                         if (!String.IsNullOrEmpty (host))
 154                                 this.host = host;
 155
 156                         if (port != 0)
 157                                 this.port = port;
 158                         else if (this.port == 0)
 159                                 this.port = 25;
 160                 }
 161
 162                 #endregion // Constructors
 163
 164                 #region Properties
 165
 166 #if SECURITY_DEP
 167                 [MonoTODO("Client certificates not used")]
 168                 public X509CertificateCollection ClientCertificates {
 169                         get {
 170                                 if (clientCertificates == null)
 171                                         clientCertificates = new X509CertificateCollection ();
 172                                 return clientCertificates;
 173                         }
 174                 }
 175 #endif
 176
 177 #if NET_4_0
 178                 public
 179 #endif
 180                 string TargetName { get; set; }
 181
 182                 public ICredentialsByHost Credentials {
 183                         get { return credentials; }
 184                         set {
 185                                 CheckState ();
 186                                 credentials = value;
 187                         }
 188                 }
 189
 190                 public SmtpDeliveryMethod DeliveryMethod {
 191                         get { return deliveryMethod; }
 192                         set {
 193                                 CheckState ();
 194                                 deliveryMethod = value;
 195                         }
 196                 }
 197
 198                 public bool EnableSsl {
 199                         get { return enableSsl; }
 200                         set {
 201                                 CheckState ();
 202                                 enableSsl = value;
 203                         }
 204                 }
 205
 206                 public string Host {
 207                         get { return host; }
 208                         set {
 209                                 if (value == null)
 210                                         throw new ArgumentNullException ("value");
 211                                 if (value.Length == 0)
 212                                         throw new ArgumentException ("An empty string is not allowed.", "value");
 213                                 CheckState ();
 214                                 host = value;
 215                         }
 216                 }
 217
 218                 public string PickupDirectoryLocation {
 219                         get { return pickupDirectoryLocation; }
 220                         set { pickupDirectoryLocation = value; }
 221                 }
 222
 223                 public int Port {
 224                         get { return port; }
 225                         set {
 226                                 if (value <= 0)
 227                                         throw new ArgumentOutOfRangeException ("value");
 228                                 CheckState ();
 229                                 port = value;
 230                         }
 231                 }
 232
 233                 [MonoTODO]
 234                 public ServicePoint ServicePoint {
 235                         get { throw new NotImplementedException (); }
 236                 }
 237
 238                 public int Timeout {
 239                         get { return timeout; }
 240                         set {
 241                                 if (value < 0)
 242                                         throw new ArgumentOutOfRangeException ("value");
 243                                 CheckState ();
 244                                 timeout = value;
 245                         }
 246                 }
 247
 248                 public bool UseDefaultCredentials {
 249                         get { return false; }
 250                         [MonoNotSupported ("no DefaultCredential support in Mono")]
 251                         set {
 252                                 if (value)
 253                                         throw new NotImplementedException ("Default credentials are not supported");
 254                                 CheckState ();
 255                         }
 256                 }
 257
 258                 #endregion // Properties
 259
 260                 #region Events
 261
 262                 public event SendCompletedEventHandler SendCompleted;
 263
 264                 #endregion // Events
 265
 266                 #region Methods
 267 #if NET_4_0
 268                 public void Dispose ()
 269                 {
 270                         Dispose (true);
 271                 }
 272
 273                 [MonoTODO ("Does nothing at the moment.")]
 274                 protected virtual void Dispose (bool disposing)
 275                 {
 276                         // TODO: We should close all the connections and abort any async operations here
 277                 }
 278 #endif
 279                 private void CheckState ()
 280                 {
 281                         if (messageInProcess != null)
 282                                 throw new InvalidOperationException ("Cannot set Timeout while Sending a message");
 283                 }
 284
 285                 private static string EncodeAddress(MailAddress address)
 286                 {
 287                         if (!String.IsNullOrEmpty (address.DisplayName)) {
 288                                 string encodedDisplayName = ContentType.EncodeSubjectRFC2047 (address.DisplayName, Encoding.UTF8);
 289                                 return "\"" + encodedDisplayName + "\" <" + address.Address + ">";
 290                         }
 291                         return address.ToString ();
 292                 }
 293
 294                 private static string EncodeAddresses(MailAddressCollection addresses)
 295                 {
 296                         StringBuilder sb = new StringBuilder();
 297                         bool first = true;
 298                         foreach (MailAddress address in addresses) {
 299                                 if (!first) {
 300                                         sb.Append(", ");
 301                                 }
 302                                 sb.Append(EncodeAddress(address));
 303                                 first = false;
 304                         }
 305                         return sb.ToString();
 306                 }
 307
 308                 private string EncodeSubjectRFC2047 (MailMessage message)
 309                 {
 310                         return ContentType.EncodeSubjectRFC2047 (message.Subject, message.SubjectEncoding);
 311                 }
 312
 313                 private string EncodeBody (MailMessage message)
 314                 {
 315                         string body = message.Body;
 316                         Encoding encoding = message.BodyEncoding;
 317                         // RFC 2045 encoding
 318                         switch (message.ContentTransferEncoding) {
 319                         case TransferEncoding.SevenBit:
 320                                 return body;
 321                         case TransferEncoding.Base64:
 322                                 return Convert.ToBase64String (encoding.GetBytes (body), Base64FormattingOptions.InsertLineBreaks);
 323                         default:
 324                                 return ToQuotedPrintable (body, encoding);
 325                         }
 326                 }
 327
 328                 private string EncodeBody (AlternateView av)
 329                 {
 330                         //Encoding encoding = av.ContentType.CharSet != null ? Encoding.GetEncoding (av.ContentType.CharSet) : Encoding.UTF8;
 331
 332                         byte [] bytes = new byte [av.ContentStream.Length];
 333                         av.ContentStream.Read (bytes, 0, bytes.Length);
 334
 335                         // RFC 2045 encoding
 336                         switch (av.TransferEncoding) {
 337                         case TransferEncoding.SevenBit:
 338                                 return Encoding.ASCII.GetString (bytes);
 339                         case TransferEncoding.Base64:
 340                                 return Convert.ToBase64String (bytes, Base64FormattingOptions.InsertLineBreaks);
 341                         default:
 342                                 return ToQuotedPrintable (bytes);
 343                         }
 344                 }
 345
 346
 347                 private void EndSection (string section)
 348                 {
 349                         SendData (String.Format ("--{0}--", section));
 350                         SendData (string.Empty);
 351                 }
 352
 353                 private string GenerateBoundary ()
 354                 {
 355                         string output = GenerateBoundary (boundaryIndex);
 356                         boundaryIndex += 1;
 357                         return output;
 358                 }
 359
 360                 private static string GenerateBoundary (int index)
 361                 {
 362                         return String.Format ("--boundary_{0}_{1}", index, Guid.NewGuid ().ToString ("D"));
 363                 }
 364
 365                 private bool IsError (SmtpResponse status)
 366                 {
 367                         return ((int) status.StatusCode) >= 400;
 368                 }
 369
 370                 protected void OnSendCompleted (AsyncCompletedEventArgs e)
 371                 {
 372                         try {
 373                                 if (SendCompleted != null)
 374                                         SendCompleted (this, e);
 375                         } finally {
 376                                 worker = null;
 377                                 user_async_state = null;
 378                         }
 379                 }
 380
 381                 private void CheckCancellation ()
 382                 {
 383                         if (worker != null && worker.CancellationPending)
 384                                 throw new CancellationException ();
 385                 }
 386
 387                 private SmtpResponse Read () {
 388                         byte [] buffer = new byte [512];
 389                         int position = 0;
 390                         bool lastLine = false;
 391
 392                         do {
 393                                 CheckCancellation ();
 394
 395                                 int readLength = stream.Read (buffer, position, buffer.Length - position);
 396                                 if (readLength > 0) {
 397                                         int available = position + readLength - 1;
 398                                         if (available > 4 && (buffer [available] == '\n' || buffer [available] == '\r'))
 399                                                 for (int index = available - 3; ; index--) {
 400                                                         if (index < 0 || buffer [index] == '\n' || buffer [index] == '\r') {
 401                                                                 lastLine = buffer [index + 4] == ' ';
 402                                                                 break;
 403                                                         }
 404                                                 }
 405
 406                                         // move position
 407                                         position += readLength;
 408
 409                                         // check if buffer is full
 410                                         if (position == buffer.Length) {
 411                                                 byte [] newBuffer = new byte [buffer.Length * 2];
 412                                                 Array.Copy (buffer, 0, newBuffer, 0, buffer.Length);
 413                                                 buffer = newBuffer;
 414                                         }
 415                                 }
 416                                 else {
 417                                         break;
 418                                 }
 419                         } while (!lastLine);
 420
 421                         if (position > 0) {
 422                                 Encoding encoding = new ASCIIEncoding ();
 423
 424                                 string line = encoding.GetString (buffer, 0, position - 1);
 425
 426                                 // parse the line to the lastResponse object
 427                                 SmtpResponse response = SmtpResponse.Parse (line);
 428
 429                                 return response;
 430                         } else {
 431                                 throw new System.IO.IOException ("Connection closed");
 432                         }
 433                 }
 434
 435                 void ResetExtensions()
 436                 {
 437                         authMechs = AuthMechs.None;
 438                 }
 439
 440                 void ParseExtensions (string extens)
 441                 {
 442                         string[] parts = extens.Split ('\n');
 443
 444                         foreach (string part in parts) {
 445                                 if (part.Length < 4)
 446                                         continue;
 447
 448                                 string start = part.Substring (4);
 449                                 if (start.StartsWith ("AUTH ", StringComparison.Ordinal)) {
 450                                         string[] options = start.Split (' ');
 451                                         for (int k = 1; k < options.Length; k++) {
 452                                                 string option = options[k].Trim();
 453                                                 // GSSAPI, KERBEROS_V4, NTLM not supported
 454                                                 switch (option) {
 455                                                 /*
 456                                                 case "CRAM-MD5":
 457                                                         authMechs |= AuthMechs.CramMD5;
 458                                                         break;
 459                                                 case "DIGEST-MD5":
 460                                                         authMechs |= AuthMechs.DigestMD5;
 461                                                         break;
 462                                                 */
 463                                                 case "LOGIN":
 464                                                         authMechs |= AuthMechs.Login;
 465                                                         break;
 466                                                 case "PLAIN":
 467                                                         authMechs |= AuthMechs.Plain;
 468                                                         break;
 469                                                 }
 470                                         }
 471                                 }
 472                         }
 473                 }
 474
 475                 public void Send (MailMessage message)
 476                 {
 477                         if (message == null)
 478                                 throw new ArgumentNullException ("message");
 479
 480                         if (deliveryMethod == SmtpDeliveryMethod.Network && (Host == null || Host.Trim ().Length == 0))
 481                                 throw new InvalidOperationException ("The SMTP host was not specified");
 482                         else if (deliveryMethod == SmtpDeliveryMethod.PickupDirectoryFromIis)
 483                                 throw new NotSupportedException("IIS delivery is not supported");
 484
 485                         if (port == 0)
 486                                 port = 25;
 487
 488                         // Block while sending
 489                         mutex.WaitOne ();
 490                         try {
 491                                 messageInProcess = message;
 492                                 if (deliveryMethod == SmtpDeliveryMethod.SpecifiedPickupDirectory)
 493                                         SendToFile (message);
 494                                 else
 495                                         SendInternal (message);
 496                         } catch (CancellationException) {
 497                                 // This exception is introduced for convenient cancellation process.
 498                         } catch (SmtpException) {
 499                                 throw;
 500                         } catch (Exception ex) {
 501                                 throw new SmtpException ("Message could not be sent.", ex);
 502                         } finally {
 503                                 // Release the mutex to allow other threads access
 504                                 mutex.ReleaseMutex ();
 505                                 messageInProcess = null;
 506                         }
 507                 }
 508
 509                 private void SendInternal (MailMessage message)
 510                 {
 511                         CheckCancellation ();
 512
 513                         try {
 514                                 client = new TcpClient (host, port);
 515                                 stream = client.GetStream ();
 516                                 // FIXME: this StreamWriter creation is bogus.
 517                                 // It expects as if a Stream were able to switch to SSL
 518                                 // mode (such behavior is only in Mainsoft Socket API).
 519                                 writer = new StreamWriter (stream);
 520                                 reader = new StreamReader (stream);
 521
 522                                 SendCore (message);
 523                         } finally {
 524                                 if (writer != null)
 525                                         writer.Close ();
 526                                 if (reader != null)
 527                                         reader.Close ();
 528                                 if (stream != null)
 529                                         stream.Close ();
 530                                 if (client != null)
 531                                         client.Close ();
 532                         }
 533                 }
 534
 535                 // FIXME: simple implementation, could be brushed up.
 536                 private void SendToFile (MailMessage message)
 537                 {
 538                         if (!Path.IsPathRooted (pickupDirectoryLocation))
 539                                 throw new SmtpException("Only absolute directories are allowed for pickup directory.");
 540
 541                         string filename = Path.Combine (pickupDirectoryLocation,
 542                                 Guid.NewGuid() + ".eml");
 543
 544                         try {
 545                                 writer = new StreamWriter(filename);
 546
 547                                 // FIXME: See how Microsoft fixed the bug about envelope senders, and how it actually represents the info in .eml file headers
 548                                 //        For all we know, defaultFrom may be the envelope sender
 549                                 // For now, we are no worse than some versions of .NET
 550                                 MailAddress from = message.From;
 551                                 if (from == null)
 552                                         from = defaultFrom;
 553
 554                                 SendHeader (HeaderName.Date, DateTime.Now.ToString ("ddd, dd MMM yyyy HH':'mm':'ss zzz", DateTimeFormatInfo.InvariantInfo));
 555                                 SendHeader (HeaderName.From, EncodeAddress(from));
 556                                 SendHeader (HeaderName.To, EncodeAddresses(message.To));
 557                                 if (message.CC.Count > 0)
 558                                         SendHeader (HeaderName.Cc, EncodeAddresses(message.CC));
 559                                 SendHeader (HeaderName.Subject, EncodeSubjectRFC2047 (message));
 560
 561                                 foreach (string s in message.Headers.AllKeys)
 562                                         SendHeader (s, message.Headers [s]);
 563
 564                                 AddPriorityHeader (message);
 565
 566                                 boundaryIndex = 0;
 567                                 if (message.Attachments.Count > 0)
 568                                         SendWithAttachments (message);
 569                                 else
 570                                         SendWithoutAttachments (message, null, false);
 571
 572
 573                         } finally {
 574                                 if (writer != null) writer.Close(); writer = null;
 575                         }
 576                 }
 577
 578                 private void SendCore (MailMessage message)
 579                 {
 580                         SmtpResponse status;
 581
 582                         status = Read ();
 583                         if (IsError (status))
 584                                 throw new SmtpException (status.StatusCode, status.Description);
 585
 586                         // EHLO
 587
 588                         // FIXME: parse the list of extensions so we don't bother wasting
 589                         // our time trying commands if they aren't supported.
 590                         status = SendCommand ("EHLO " + Dns.GetHostName ());
 591
 592                         if (IsError (status)) {
 593                                 status = SendCommand ("HELO " + Dns.GetHostName ());
 594
 595                                 if (IsError (status))
 596                                         throw new SmtpException (status.StatusCode, status.Description);
 597                         } else {
 598                                 // Parse ESMTP extensions
 599                                 string extens = status.Description;
 600
 601                                 if (extens != null)
 602                                         ParseExtensions (extens);
 603                         }
 604
 605                         if (enableSsl) {
 606                                 InitiateSecureConnection ();
 607                                 ResetExtensions();
 608                                 writer = new StreamWriter (stream);
 609                                 reader = new StreamReader (stream);
 610                                 status = SendCommand ("EHLO " + Dns.GetHostName ());
 611
 612                                 if (IsError (status)) {
 613                                         status = SendCommand ("HELO " + Dns.GetHostName ());
 614
 615                                         if (IsError (status))
 616                                                 throw new SmtpException (status.StatusCode, status.Description);
 617                                 } else {
 618                                         // Parse ESMTP extensions
 619                                         string extens = status.Description;
 620                                         if (extens != null)
 621                                                 ParseExtensions (extens);
 622                                 }
 623                         }
 624
 625                         if (authMechs != AuthMechs.None)
 626                                 Authenticate ();
 627
 628                         // The envelope sender: use 'Sender:' in preference of 'From:'
 629                         MailAddress sender = message.Sender;
 630                         if (sender == null)
 631                                 sender = message.From;
 632                         if (sender == null)
 633                                 sender = defaultFrom;
 634
 635                         // MAIL FROM:
 636                         status = SendCommand ("MAIL FROM:<" + sender.Address + '>');
 637                         if (IsError (status)) {
 638                                 throw new SmtpException (status.StatusCode, status.Description);
 639                         }
 640
 641                         // Send RCPT TO: for all recipients
 642                         List<SmtpFailedRecipientException> sfre = new List<SmtpFailedRecipientException> ();
 643
 644                         for (int i = 0; i < message.To.Count; i ++) {
 645                                 status = SendCommand ("RCPT TO:<" + message.To [i].Address + '>');
 646                                 if (IsError (status))
 647                                         sfre.Add (new SmtpFailedRecipientException (status.StatusCode, message.To [i].Address));
 648                         }
 649                         for (int i = 0; i < message.CC.Count; i ++) {
 650                                 status = SendCommand ("RCPT TO:<" + message.CC [i].Address + '>');
 651                                 if (IsError (status))
 652                                         sfre.Add (new SmtpFailedRecipientException (status.StatusCode, message.CC [i].Address));
 653                         }
 654                         for (int i = 0; i < message.Bcc.Count; i ++) {
 655                                 status = SendCommand ("RCPT TO:<" + message.Bcc [i].Address + '>');
 656                                 if (IsError (status))
 657                                         sfre.Add (new SmtpFailedRecipientException (status.StatusCode, message.Bcc [i].Address));
 658                         }
 659
 660 #if TARGET_JVM // List<T>.ToArray () is not supported
 661                         if (sfre.Count > 0) {
 662                                 SmtpFailedRecipientException[] xs = new SmtpFailedRecipientException[sfre.Count];
 663                                 sfre.CopyTo (xs);
 664                                 throw new SmtpFailedRecipientsException ("failed recipients", xs);
 665                         }
 666 #else
 667                         if (sfre.Count >0)
 668                                 throw new SmtpFailedRecipientsException ("failed recipients", sfre.ToArray ());
 669 #endif
 670
 671                         // DATA
 672                         status = SendCommand ("DATA");
 673                         if (IsError (status))
 674                                 throw new SmtpException (status.StatusCode, status.Description);
 675
 676                         // Send message headers
 677                         string dt = DateTime.Now.ToString ("ddd, dd MMM yyyy HH':'mm':'ss zzz", DateTimeFormatInfo.InvariantInfo);
 678                         // remove ':' from time zone offset (e.g. from "+01:00")
 679                         dt = dt.Remove (dt.Length - 3, 1);
 680                         SendHeader (HeaderName.Date, dt);
 681
 682                         MailAddress from = message.From;
 683                         if (from == null)
 684                                 from = defaultFrom;
 685
 686                         SendHeader (HeaderName.From, EncodeAddress (from));
 687                         SendHeader (HeaderName.To, EncodeAddresses (message.To));
 688                         if (message.CC.Count > 0)
 689                                 SendHeader (HeaderName.Cc, EncodeAddresses (message.CC));
 690                         SendHeader (HeaderName.Subject, EncodeSubjectRFC2047 (message));
 691
 692                         string v = "normal";
 693
 694                         switch (message.Priority){
 695                         case MailPriority.Normal:
 696                                 v = "normal";
 697                                 break;
 698
 699                         case MailPriority.Low:
 700                                 v = "non-urgent";
 701                                 break;
 702
 703                         case MailPriority.High:
 704                                 v = "urgent";
 705                                 break;
 706                         }
 707                         SendHeader ("Priority", v);
 708                         if (message.Sender != null)
 709                                 SendHeader ("Sender", EncodeAddress (message.Sender));
 710                         if (message.ReplyToList.Count > 0)
 711                                 SendHeader ("Reply-To", EncodeAddresses (message.ReplyToList));
 712
 713 #if NET_4_0
 714                         foreach (string s in message.Headers.AllKeys)
 715                                 SendHeader (s, ContentType.EncodeSubjectRFC2047 (message.Headers [s], message.HeadersEncoding));
 716 #else
 717                         foreach (string s in message.Headers.AllKeys)
 718                                 SendHeader (s, message.Headers [s]);
 719 #endif
 720
 721                         AddPriorityHeader (message);
 722
 723                         boundaryIndex = 0;
 724                         if (message.Attachments.Count > 0)
 725                                 SendWithAttachments (message);
 726                         else
 727                                 SendWithoutAttachments (message, null, false);
 728
 729                         SendDot ();
 730
 731                         status = Read ();
 732                         if (IsError (status))
 733                                 throw new SmtpException (status.StatusCode, status.Description);
 734
 735                         try {
 736                                 status = SendCommand ("QUIT");
 737                         } catch (System.IO.IOException) {
 738                                 // We excuse server for the rude connection closing as a response to QUIT
 739                         }
 740                 }
 741
 742                 public void Send (string from, string to, string subject, string body)
 743                 {
 744                         Send (new MailMessage (from, to, subject, body));
 745                 }
 746
 747 #if NET_4_5
 748                 public Task SendMailAsync (MailMessage message)
 749                 {
 750                         var tcs = new TaskCompletionSource<object> ();
 751                         SendCompletedEventHandler handler = null;
 752                         handler = (s, e) => SendMailAsyncCompletedHandler (tcs, e, handler, this);
 753                         SendCompleted += handler;
 754                         SendAsync (message, tcs);
 755                         return tcs.Task;
 756                 }
 757
 758                 public Task SendMailAsync (string from, string recipients, string subject, string body)
 759                 {
 760                         return SendMailAsync (new MailMessage (from, recipients, subject, body));
 761                 }
 762
 763                 static void SendMailAsyncCompletedHandler (TaskCompletionSource<object> source, AsyncCompletedEventArgs e, SendCompletedEventHandler handler, SmtpClient client)
 764                 {
 765                         if (handler != e.UserState)
 766                                 return;
 767
 768                         client.SendCompleted -= handler;
 769
 770                         if (e.Error != null) {
 771                                 source.SetException (e.Error);
 772                                 return;
 773                         }
 774
 775                         if (e.Cancelled) {
 776                                 source.SetCanceled ();
 777                                 return;
 778                         }
 779
 780                         source.SetResult (null);
 781                 }
 782 #endif
 783
 784                 private void SendDot()
 785                 {
 786                         writer.Write(".\r\n");
 787                         writer.Flush();
 788                 }
 789
 790                 private void SendData (string data)
 791                 {
 792                         if (String.IsNullOrEmpty (data)) {
 793                                 writer.Write("\r\n");
 794                                 writer.Flush();
 795                                 return;
 796                         }
 797
 798                         StringReader sr = new StringReader (data);
 799                         string line;
 800                         bool escapeDots = deliveryMethod == SmtpDeliveryMethod.Network;
 801                         while ((line = sr.ReadLine ()) != null) {
 802                                 CheckCancellation ();
 803
 804                                 if (escapeDots) {
 805                                         int i;
 806                                         for (i = 0; i < line.Length; i++) {
 807                                                 if (line[i] != '.')
 808                                                         break;
 809                                         }
 810                                         if (i > 0 && i == line.Length) {
 811                                                 line += ".";
 812                                         }
 813                                 }
 814                                 writer.Write (line);
 815                                 writer.Write ("\r\n");
 816                         }
 817                         writer.Flush ();
 818                 }
 819
 820                 public void SendAsync (MailMessage message, object userToken)
 821                 {
 822                         if (worker != null)
 823                                 throw new InvalidOperationException ("Another SendAsync operation is in progress");
 824
 825                         worker = new BackgroundWorker ();
 826                         worker.DoWork += delegate (object o, DoWorkEventArgs ea) {
 827                                 try {
 828                                         user_async_state = ea.Argument;
 829                                         Send (message);
 830                                 } catch (Exception ex) {
 831                                         ea.Result = ex;
 832                                         throw ex;
 833                                 }
 834                         };
 835                         worker.WorkerSupportsCancellation = true;
 836                         worker.RunWorkerCompleted += delegate (object o, RunWorkerCompletedEventArgs ea) {
 837                                 // Note that RunWorkerCompletedEventArgs.UserState cannot be used (LAMESPEC)
 838                                 OnSendCompleted (new AsyncCompletedEventArgs (ea.Error, ea.Cancelled, user_async_state));
 839                         };
 840                         worker.RunWorkerAsync (userToken);
 841                 }
 842
 843                 public void SendAsync (string from, string to, string subject, string body, object userToken)
 844                 {
 845                         SendAsync (new MailMessage (from, to, subject, body), userToken);
 846                 }
 847
 848                 public void SendAsyncCancel ()
 849                 {
 850                         if (worker == null)
 851                                 throw new InvalidOperationException ("SendAsync operation is not in progress");
 852                         worker.CancelAsync ();
 853                 }
 854
 855                 private void AddPriorityHeader (MailMessage message) {
 856                         switch (message.Priority) {
 857                         case MailPriority.High:
 858                                 SendHeader (HeaderName.Priority, "Urgent");
 859                                 SendHeader (HeaderName.Importance, "high");
 860                                 SendHeader (HeaderName.XPriority, "1");
 861                                 break;
 862                         case MailPriority.Low:
 863                                 SendHeader (HeaderName.Priority, "Non-Urgent");
 864                                 SendHeader (HeaderName.Importance, "low");
 865                                 SendHeader (HeaderName.XPriority, "5");
 866                                 break;
 867                         }
 868                 }
 869
 870                 private void SendSimpleBody (MailMessage message) {
 871                         SendHeader (HeaderName.ContentType, message.BodyContentType.ToString ());
 872                         if (message.ContentTransferEncoding != TransferEncoding.SevenBit)
 873                                 SendHeader (HeaderName.ContentTransferEncoding, GetTransferEncodingName (message.ContentTransferEncoding));
 874                         SendData (string.Empty);
 875
 876                         SendData (EncodeBody (message));
 877                 }
 878
 879                 private void SendBodylessSingleAlternate (AlternateView av) {
 880                         SendHeader (HeaderName.ContentType, av.ContentType.ToString ());
 881                         if (av.TransferEncoding != TransferEncoding.SevenBit)
 882                                 SendHeader (HeaderName.ContentTransferEncoding, GetTransferEncodingName (av.TransferEncoding));
 883                         SendData (string.Empty);
 884
 885                         SendData (EncodeBody (av));
 886                 }
 887
 888                 private void SendWithoutAttachments (MailMessage message, string boundary, bool attachmentExists)
 889                 {
 890                         if (message.Body == null && message.AlternateViews.Count == 1)
 891                                 SendBodylessSingleAlternate (message.AlternateViews [0]);
 892                         else if (message.AlternateViews.Count > 0)
 893                                 SendBodyWithAlternateViews (message, boundary, attachmentExists);
 894                         else
 895                                 SendSimpleBody (message);
 896                 }
 897
 898
 899                 private void SendWithAttachments (MailMessage message) {
 900                         string boundary = GenerateBoundary ();
 901
 902                         // first "multipart/mixed"
 903                         ContentType messageContentType = new ContentType ();
 904                         messageContentType.Boundary = boundary;
 905                         messageContentType.MediaType = "multipart/mixed";
 906                         messageContentType.CharSet = null;
 907
 908                         SendHeader (HeaderName.ContentType, messageContentType.ToString ());
 909                         SendData (String.Empty);
 910
 911                         // body section
 912                         Attachment body = null;
 913
 914                         if (message.AlternateViews.Count > 0)
 915                                 SendWithoutAttachments (message, boundary, true);
 916                         else {
 917                                 body = Attachment.CreateAttachmentFromString (message.Body, null, message.BodyEncoding, message.IsBodyHtml ? "text/html" : "text/plain");
 918                                 message.Attachments.Insert (0, body);
 919                         }
 920
 921                         try {
 922                                 SendAttachments (message, body, boundary);
 923                         } finally {
 924                                 if (body != null)
 925                                         message.Attachments.Remove (body);
 926                         }
 927
 928                         EndSection (boundary);
 929                 }
 930
 931                 private void SendBodyWithAlternateViews (MailMessage message, string boundary, bool attachmentExists)
 932                 {
 933                         AlternateViewCollection alternateViews = message.AlternateViews;
 934
 935                         string inner_boundary = GenerateBoundary ();
 936
 937                         ContentType messageContentType = new ContentType ();
 938                         messageContentType.Boundary = inner_boundary;
 939                         messageContentType.MediaType = "multipart/alternative";
 940
 941                         if (!attachmentExists) {
 942                                 SendHeader (HeaderName.ContentType, messageContentType.ToString ());
 943                                 SendData (String.Empty);
 944                         }
 945
 946                         // body section
 947                         AlternateView body = null;
 948                         if (message.Body != null) {
 949                                 body = AlternateView.CreateAlternateViewFromString (message.Body, message.BodyEncoding, message.IsBodyHtml ? "text/html" : "text/plain");
 950                                 alternateViews.Insert (0, body);
 951                                 StartSection (boundary, messageContentType);
 952                         }
 953
 954 try {
 955                         // alternate view sections
 956                         foreach (AlternateView av in alternateViews) {
 957
 958                                 string alt_boundary = null;
 959                                 ContentType contentType;
 960                                 if (av.LinkedResources.Count > 0) {
 961                                         alt_boundary = GenerateBoundary ();
 962                                         contentType = new ContentType ("multipart/related");
 963                                         contentType.Boundary = alt_boundary;
 964
 965                                         contentType.Parameters ["type"] = av.ContentType.ToString ();
 966                                         StartSection (inner_boundary, contentType);
 967                                         StartSection (alt_boundary, av.ContentType, av);
 968                                 } else {
 969                                         contentType = new ContentType (av.ContentType.ToString ());
 970                                         StartSection (inner_boundary, contentType, av);
 971                                 }
 972
 973                                 switch (av.TransferEncoding) {
 974                                 case TransferEncoding.Base64:
 975                                         byte [] content = new byte [av.ContentStream.Length];
 976                                         av.ContentStream.Read (content, 0, content.Length);
 977 #if TARGET_JVM
 978                                         SendData (Convert.ToBase64String (content));
 979 #else
 980                                             SendData (Convert.ToBase64String (content, Base64FormattingOptions.InsertLineBreaks));
 981 #endif
 982                                         break;
 983                                 case TransferEncoding.QuotedPrintable:
 984                                         byte [] bytes = new byte [av.ContentStream.Length];
 985                                         av.ContentStream.Read (bytes, 0, bytes.Length);
 986                                         SendData (ToQuotedPrintable (bytes));
 987                                         break;
 988                                 case TransferEncoding.SevenBit:
 989                                 case TransferEncoding.Unknown:
 990                                         content = new byte [av.ContentStream.Length];
 991                                         av.ContentStream.Read (content, 0, content.Length);
 992                                         SendData (Encoding.ASCII.GetString (content));
 993                                         break;
 994                                 }
 995
 996                                 if (av.LinkedResources.Count > 0) {
 997                                         SendLinkedResources (message, av.LinkedResources, alt_boundary);
 998                                         EndSection (alt_boundary);
 999                                 }
1000
1001                                 if (!attachmentExists)
1002                                         SendData (string.Empty);
1003                         }
1004
1005 } finally {
1006                         if (body != null)
1007                                 alternateViews.Remove (body);
1008 }
1009                         EndSection (inner_boundary);
1010                 }
1011
1012                 private void SendLinkedResources (MailMessage message, LinkedResourceCollection resources, string boundary)
1013                 {
1014                         foreach (LinkedResource lr in resources) {
1015                                 StartSection (boundary, lr.ContentType, lr);
1016
1017                                 switch (lr.TransferEncoding) {
1018                                 case TransferEncoding.Base64:
1019                                         byte [] content = new byte [lr.ContentStream.Length];
1020                                         lr.ContentStream.Read (content, 0, content.Length);
1021 #if TARGET_JVM
1022                                         SendData (Convert.ToBase64String (content));
1023 #else
1024                                             SendData (Convert.ToBase64String (content, Base64FormattingOptions.InsertLineBreaks));
1025 #endif
1026                                         break;
1027                                 case TransferEncoding.QuotedPrintable:
1028                                         byte [] bytes = new byte [lr.ContentStream.Length];
1029                                         lr.ContentStream.Read (bytes, 0, bytes.Length);
1030                                         SendData (ToQuotedPrintable (bytes));
1031                                         break;
1032                                 case TransferEncoding.SevenBit:
1033                                 case TransferEncoding.Unknown:
1034                                         content = new byte [lr.ContentStream.Length];
1035                                         lr.ContentStream.Read (content, 0, content.Length);
1036                                         SendData (Encoding.ASCII.GetString (content));
1037                                         break;
1038                                 }
1039                         }
1040                 }
1041
1042                 private void SendAttachments (MailMessage message, Attachment body, string boundary) {
1043                         foreach (Attachment att in message.Attachments) {
1044                                 ContentType contentType = new ContentType (att.ContentType.ToString ());
1045                                 if (att.Name != null) {
1046                                         contentType.Name = att.Name;
1047                                         if (att.NameEncoding != null)
1048                                                 contentType.CharSet = att.NameEncoding.HeaderName;
1049                                         att.ContentDisposition.FileName = att.Name;
1050                                 }
1051                                 StartSection (boundary, contentType, att, att != body);
1052
1053                                 byte [] content = new byte [att.ContentStream.Length];
1054                                 att.ContentStream.Read (content, 0, content.Length);
1055                                 switch (att.TransferEncoding) {
1056                                 case TransferEncoding.Base64:
1057 #if TARGET_JVM
1058                                         SendData (Convert.ToBase64String (content));
1059 #else
1060                                         SendData (Convert.ToBase64String (content, Base64FormattingOptions.InsertLineBreaks));
1061 #endif
1062                                         break;
1063                                 case TransferEncoding.QuotedPrintable:
1064                                         SendData (ToQuotedPrintable (content));
1065                                         break;
1066                                 case TransferEncoding.SevenBit:
1067                                 case TransferEncoding.Unknown:
1068                                         SendData (Encoding.ASCII.GetString (content));
1069                                         break;
1070                                 }
1071
1072                                 SendData (string.Empty);
1073                         }
1074                 }
1075
1076                 private SmtpResponse SendCommand (string command)
1077                 {
1078                         writer.Write (command);
1079                         // Certain SMTP servers will reject mail sent with unix line-endings; see http://cr.yp.to/docs/smtplf.html
1080                         writer.Write ("\r\n");
1081                         writer.Flush ();
1082                         return Read ();
1083                 }
1084
1085                 private void SendHeader (string name, string value)
1086                 {
1087                         SendData (String.Format ("{0}: {1}", name, value));
1088                 }
1089
1090                 private void StartSection (string section, ContentType sectionContentType)
1091                 {
1092                         SendData (String.Format ("--{0}", section));
1093                         SendHeader ("content-type", sectionContentType.ToString ());
1094                         SendData (string.Empty);
1095                 }
1096
1097                 private void StartSection (string section, ContentType sectionContentType, AttachmentBase att)
1098                 {
1099                         SendData (String.Format ("--{0}", section));
1100                         SendHeader ("content-type", sectionContentType.ToString ());
1101                         SendHeader ("content-transfer-encoding", GetTransferEncodingName (att.TransferEncoding));
1102                         if (!string.IsNullOrEmpty (att.ContentId))
1103                                 SendHeader("content-ID", "<" + att.ContentId + ">");
1104                         SendData (string.Empty);
1105                 }
1106
1107                 private void StartSection (string section, ContentType sectionContentType, Attachment att, bool sendDisposition) {
1108                         SendData (String.Format ("--{0}", section));
1109                         if (!string.IsNullOrEmpty (att.ContentId))
1110                                 SendHeader("content-ID", "<" + att.ContentId + ">");
1111                         SendHeader ("content-type", sectionContentType.ToString ());
1112                         SendHeader ("content-transfer-encoding", GetTransferEncodingName (att.TransferEncoding));
1113                         if (sendDisposition)
1114                                 SendHeader ("content-disposition", att.ContentDisposition.ToString ());
1115                         SendData (string.Empty);
1116                 }
1117
1118                 // use proper encoding to escape input
1119                 private string ToQuotedPrintable (string input, Encoding enc)
1120                 {
1121                         byte [] bytes = enc.GetBytes (input);
1122                         return ToQuotedPrintable (bytes);
1123                 }
1124
1125                 private string ToQuotedPrintable (byte [] bytes)
1126                 {
1127                         StringWriter writer = new StringWriter ();
1128                         int charsInLine = 0;
1129                         int curLen;
1130                         StringBuilder sb = new StringBuilder("=", 3);
1131                         byte equalSign = (byte)'=';
1132                         char c = (char)0;
1133
1134                         foreach (byte i in bytes) {
1135                                 if (i > 127 || i == equalSign) {
1136                                         sb.Length = 1;
1137                                         sb.Append(Convert.ToString (i, 16).ToUpperInvariant ());
1138                                         curLen = 3;
1139                                 } else {
1140                                         c = Convert.ToChar (i);
1141                                         if (c == '\r' || c == '\n') {
1142                                                 writer.Write (c);
1143                                                 charsInLine = 0;
1144                                                 continue;
1145                                         }
1146                                         curLen = 1;
1147                                 }
1148
1149                                 charsInLine += curLen;
1150                                 if (charsInLine > 75) {
1151                                         writer.Write ("=\r\n");
1152                                         charsInLine = curLen;
1153                                 }
1154                                 if (curLen == 1)
1155                                         writer.Write (c);
1156                                 else
1157                                         writer.Write (sb.ToString ());
1158                         }
1159
1160                         return writer.ToString ();
1161                 }
1162                 private static string GetTransferEncodingName (TransferEncoding encoding)
1163                 {
1164                         switch (encoding) {
1165                         case TransferEncoding.QuotedPrintable:
1166                                 return "quoted-printable";
1167                         case TransferEncoding.SevenBit:
1168                                 return "7bit";
1169                         case TransferEncoding.Base64:
1170                                 return "base64";
1171                         }
1172                         return "unknown";
1173                 }
1174
1175 #if SECURITY_DEP
1176                 RemoteCertificateValidationCallback callback = delegate (object sender,
1177                                                                          X509Certificate certificate,
1178                                                                          X509Chain chain,
1179                                                                          SslPolicyErrors sslPolicyErrors) {
1180                         // honor any exciting callback defined on ServicePointManager
1181                         if (ServicePointManager.ServerCertificateValidationCallback != null)
1182                                 return ServicePointManager.ServerCertificateValidationCallback (sender, certificate, chain, sslPolicyErrors);
1183                         // otherwise provide our own
1184                         if (sslPolicyErrors != SslPolicyErrors.None)
1185                                 throw new InvalidOperationException ("SSL authentication error: " + sslPolicyErrors);
1186                         return true;
1187                         };
1188 #endif
1189
1190                 private void InitiateSecureConnection () {
1191                         SmtpResponse response = SendCommand ("STARTTLS");
1192
1193                         if (IsError (response)) {
1194                                 throw new SmtpException (SmtpStatusCode.GeneralFailure, "Server does not support secure connections.");
1195                         }
1196
1197 #if TARGET_JVM
1198                         ((NetworkStream) stream).ChangeToSSLSocket ();
1199 #elif SECURITY_DEP
1200                         SslStream sslStream = new SslStream (stream, false, callback, null);
1201                         CheckCancellation ();
1202                         sslStream.AuthenticateAsClient (Host, this.ClientCertificates, SslProtocols.Default, false);
1203                         stream = sslStream;
1204
1205 #else
1206                         throw new SystemException ("You are using an incomplete System.dll build");
1207 #endif
1208                 }
1209
1210                 void Authenticate ()
1211                 {
1212                         string user = null, pass = null;
1213
1214                         if (UseDefaultCredentials) {
1215                                 user = CredentialCache.DefaultCredentials.GetCredential (new System.Uri ("smtp://" + host), "basic").UserName;
1216                                 pass =  CredentialCache.DefaultCredentials.GetCredential (new System.Uri ("smtp://" + host), "basic").Password;
1217                         } else if (Credentials != null) {
1218                                 user = Credentials.GetCredential (host, port, "smtp").UserName;
1219                                 pass = Credentials.GetCredential (host, port, "smtp").Password;
1220                         } else {
1221                                 return;
1222                         }
1223
1224                         Authenticate (user, pass);
1225                 }
1226
1227                 void CheckStatus (SmtpResponse status, int i)
1228                 {
1229                         if (((int) status.StatusCode) != i)
1230                                 throw new SmtpException (status.StatusCode, status.Description);
1231                 }
1232
1233                 void ThrowIfError (SmtpResponse status)
1234                 {
1235                         if (IsError (status))
1236                                 throw new SmtpException (status.StatusCode, status.Description);
1237                 }
1238
1239                 void Authenticate (string user, string password)
1240                 {
1241                         if (authMechs == AuthMechs.None)
1242                                 return;
1243
1244                         SmtpResponse status;
1245                         /*
1246                         if ((authMechs & AuthMechs.DigestMD5) != 0) {
1247                                 status = SendCommand ("AUTH DIGEST-MD5");
1248                                 CheckStatus (status, 334);
1249                                 string challenge = Encoding.ASCII.GetString (Convert.FromBase64String (status.Description.Substring (4)));
1250                                 Console.WriteLine ("CHALLENGE: {0}", challenge);
1251                                 DigestSession session = new DigestSession ();
1252                                 session.Parse (false, challenge);
1253                                 string response = session.Authenticate (this, user, password);
1254                                 status = SendCommand (Convert.ToBase64String (Encoding.UTF8.GetBytes (response)));
1255                                 CheckStatus (status, 235);
1256                         } else */
1257                         if ((authMechs & AuthMechs.Login) != 0) {
1258                                 status = SendCommand ("AUTH LOGIN");
1259                                 CheckStatus (status, 334);
1260                                 status = SendCommand (Convert.ToBase64String (Encoding.UTF8.GetBytes (user)));
1261                                 CheckStatus (status, 334);
1262                                 status = SendCommand (Convert.ToBase64String (Encoding.UTF8.GetBytes (password)));
1263                                 CheckStatus (status, 235);
1264                         } else if ((authMechs & AuthMechs.Plain) != 0) {
1265                                 string s = String.Format ("\0{0}\0{1}", user, password);
1266                                 s = Convert.ToBase64String (Encoding.UTF8.GetBytes (s));
1267                                 status = SendCommand ("AUTH PLAIN " + s);
1268                                 CheckStatus (status, 235);
1269                         } else {
1270                                 throw new SmtpException ("AUTH types PLAIN, LOGIN not supported by the server");
1271                         }
1272                 }
1273
1274                 #endregion // Methods
1275
1276                 // The HeaderName struct is used to store constant string values representing mail headers.
1277                 private struct HeaderName {
1278                         public const string ContentTransferEncoding = "Content-Transfer-Encoding";
1279                         public const string ContentType = "Content-Type";
1280                         public const string Bcc = "Bcc";
1281                         public const string Cc = "Cc";
1282                         public const string From = "From";
1283                         public const string Subject = "Subject";
1284                         public const string To = "To";
1285                         public const string MimeVersion = "MIME-Version";
1286                         public const string MessageId = "Message-ID";
1287                         public const string Priority = "Priority";
1288                         public const string Importance = "Importance";
1289                         public const string XPriority = "X-Priority";
1290                         public const string Date = "Date";
1291                 }
1292
1293                 // This object encapsulates the status code and description of an SMTP response.
1294                 private struct SmtpResponse {
1295                         public SmtpStatusCode StatusCode;
1296                         public string Description;
1297
1298                         public static SmtpResponse Parse (string line) {
1299                                 SmtpResponse response = new SmtpResponse ();
1300
1301                                 if (line.Length < 4)
1302                                         throw new SmtpException ("Response is to short " +
1303                                                                  line.Length + ".");
1304
1305                                 if ((line [3] != ' ') && (line [3] != '-'))
1306                                         throw new SmtpException ("Response format is wrong.(" +
1307                                                                  line + ")");
1308
1309                                 // parse the response code
1310                                 response.StatusCode = (SmtpStatusCode) Int32.Parse (line.Substring (0, 3));
1311
1312                                 // set the raw response
1313                                 response.Description = line;
1314
1315                                 return response;
1316                         }
1317                 }
1318         }
1319
1320         class CCredentialsByHost : ICredentialsByHost
1321         {
1322                 public CCredentialsByHost (string userName, string password) {
1323                         this.userName = userName;
1324                         this.password = password;
1325                 }
1326
1327                 public NetworkCredential GetCredential (string host, int port, string authenticationType) {
1328                         return new NetworkCredential (userName, password);
1329                 }
1330
1331                 private string userName;
1332                 private string password;
1333         }
1334 }
1335