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 NET_2_0
  32
  33 #if SECURITY_DEP
  34 extern alias PrebuiltSystem;
  35 #endif
  36
  37 using System;
  38 using System.Collections.Generic;
  39 using System.ComponentModel;
  40 using System.Globalization;
  41 using System.IO;
  42 using System.Net;
  43 using System.Net.Mime;
  44 using System.Net.Sockets;
  45 using System.Security.Cryptography.X509Certificates;
  46 using System.Text;
  47 using System.Threading;
  48 using System.Reflection;
  49 using System.Net.Configuration;
  50 using System.Configuration;
  51 using System.Net.Security;
  52 using System.Security.Authentication;
  53
  54 #if SECURITY_DEP
  55 using X509CertificateCollection = PrebuiltSystem::System.Security.Cryptography.X509Certificates.X509CertificateCollection;
  56 #endif
  57
  58 namespace System.Net.Mail {
  59         public class SmtpClient
  60         {
  61                 #region Fields
  62
  63                 string host;
  64                 int port;
  65                 int timeout = 100000;
  66                 ICredentialsByHost credentials;
  67                 string pickupDirectoryLocation;
  68                 SmtpDeliveryMethod deliveryMethod;
  69                 bool enableSsl;
  70 #if SECURITY_DEP
  71                 X509CertificateCollection clientCertificates;
  72 #endif
  73
  74                 TcpClient client;
  75                 Stream stream;
  76                 StreamWriter writer;
  77                 StreamReader reader;
  78                 int boundaryIndex;
  79                 MailAddress defaultFrom;
  80
  81                 MailMessage messageInProcess;
  82
  83                 BackgroundWorker worker;
  84                 object user_async_state;
  85
  86                 // ESMTP state
  87                 [Flags]
  88                 enum AuthMechs {
  89                         None        = 0,
  90                         CramMD5     = 0x01,
  91                         DigestMD5   = 0x02,
  92                         GssAPI      = 0x04,
  93                         Kerberos4   = 0x08,
  94                         Login       = 0x10,
  95                         Plain       = 0x20,
  96                 }
  97
  98                 class CancellationException : Exception
  99                 {
 100                 }
 101
 102                 AuthMechs authMechs = AuthMechs.None;
 103                 Mutex mutex = new Mutex ();
 104
 105                 #endregion // Fields
 106
 107                 #region Constructors
 108
 109                 public SmtpClient ()
 110                         : this (null, 0)
 111                 {
 112                 }
 113
 114                 public SmtpClient (string host)
 115                         : this (host, 0)
 116                 {
 117                 }
 118
 119                 public SmtpClient (string host, int port) {
 120 #if CONFIGURATION_DEP
 121                         SmtpSection cfg = (SmtpSection) ConfigurationManager.GetSection ("system.net/mailSettings/smtp");
 122
 123                         if (cfg != null) {
 124                                 this.host = cfg.Network.Host;
 125                                 this.port = cfg.Network.Port;
 126                                 TargetName = cfg.Network.TargetName;
 127                                 if (this.TargetName == null)
 128                                         TargetName = "SMTPSVC/" + (host != null ? host : "");
 129
 130
 131                                 if (cfg.Network.UserName != null) {
 132                                         string password = String.Empty;
 133
 134                                         if (cfg.Network.Password != null)
 135                                                 password = cfg.Network.Password;
 136
 137                                         Credentials = new CCredentialsByHost (cfg.Network.UserName, password);
 138                                 }
 139
 140                                 if (cfg.From != null)
 141                                         defaultFrom = new MailAddress (cfg.From);
 142                         }
 143 #endif
 144
 145                         if (!String.IsNullOrEmpty (host))
 146                                 this.host = host;
 147
 148                         if (port != 0)
 149                                 this.port = port;
 150                 }
 151
 152                 #endregion // Constructors
 153
 154                 #region Properties
 155
 156 #if SECURITY_DEP
 157                 [MonoTODO("Client certificates not used")]
 158                 public X509CertificateCollection ClientCertificates {
 159                         get {
 160                                 if (clientCertificates == null)
 161                                         clientCertificates = new X509CertificateCollection ();
 162                                 return clientCertificates;
 163                         }
 164                 }
 165 #endif
 166
 167 #if NET_4_0
 168                 public
 169 #endif
 170                 string TargetName { get; set; }
 171
 172                 public ICredentialsByHost Credentials {
 173                         get { return credentials; }
 174                         set {
 175                                 CheckState ();
 176                                 credentials = value;
 177                         }
 178                 }
 179
 180                 public SmtpDeliveryMethod DeliveryMethod {
 181                         get { return deliveryMethod; }
 182                         set {
 183                                 CheckState ();
 184                                 deliveryMethod = value;
 185                         }
 186                 }
 187
 188                 public bool EnableSsl {
 189                         get { return enableSsl; }
 190                         set {
 191                                 CheckState ();
 192                                 enableSsl = value;
 193                         }
 194                 }
 195
 196                 public string Host {
 197                         get { return host; }
 198                         set {
 199                                 if (value == null)
 200                                         throw new ArgumentNullException ("value");
 201                                 if (value.Length == 0)
 202                                         throw new ArgumentException ("An empty string is not allowed.", "value");
 203                                 CheckState ();
 204                                 host = value;
 205                         }
 206                 }
 207
 208                 public string PickupDirectoryLocation {
 209                         get { return pickupDirectoryLocation; }
 210                         set { pickupDirectoryLocation = value; }
 211                 }
 212
 213                 public int Port {
 214                         get { return port; }
 215                         set {
 216                                 if (value <= 0)
 217                                         throw new ArgumentOutOfRangeException ("value");
 218                                 CheckState ();
 219                                 port = value;
 220                         }
 221                 }
 222
 223                 [MonoTODO]
 224                 public ServicePoint ServicePoint {
 225                         get { throw new NotImplementedException (); }
 226                 }
 227
 228                 public int Timeout {
 229                         get { return timeout; }
 230                         set {
 231                                 if (value < 0)
 232                                         throw new ArgumentOutOfRangeException ("value");
 233                                 CheckState ();
 234                                 timeout = value;
 235                         }
 236                 }
 237
 238                 public bool UseDefaultCredentials {
 239                         get { return false; }
 240                         [MonoNotSupported ("no DefaultCredential support in Mono")]
 241                         set {
 242                                 if (value)
 243                                         throw new NotImplementedException ("Default credentials are not supported");
 244                                 CheckState ();
 245                         }
 246                 }
 247
 248                 #endregion // Properties
 249
 250                 #region Events
 251
 252                 public event SendCompletedEventHandler SendCompleted;
 253
 254                 #endregion // Events
 255
 256                 #region Methods
 257
 258                 private void CheckState ()
 259                 {
 260                         if (messageInProcess != null)
 261                                 throw new InvalidOperationException ("Cannot set Timeout while Sending a message");
 262                 }
 263
 264                 private static string EncodeAddress(MailAddress address)
 265                 {
 266                         string encodedDisplayName = ContentType.EncodeSubjectRFC2047 (address.DisplayName, Encoding.UTF8);
 267                         return "\"" + encodedDisplayName + "\" <" + address.Address + ">";
 268                 }
 269
 270                 private static string EncodeAddresses(MailAddressCollection addresses)
 271                 {
 272                         StringBuilder sb = new StringBuilder();
 273                         bool first = true;
 274                         foreach (MailAddress address in addresses) {
 275                                 if (!first) {
 276                                         sb.Append(", ");
 277                                 }
 278                                 sb.Append(EncodeAddress(address));
 279                                 first = false;
 280                         }
 281                         return sb.ToString();
 282                 }
 283
 284                 private string EncodeSubjectRFC2047 (MailMessage message)
 285                 {
 286                         return ContentType.EncodeSubjectRFC2047 (message.Subject, message.SubjectEncoding);
 287                 }
 288
 289                 private string EncodeBody (MailMessage message)
 290                 {
 291                         string body = message.Body;
 292                         Encoding encoding = message.BodyEncoding;
 293                         // RFC 2045 encoding
 294                         switch (message.ContentTransferEncoding) {
 295                         case TransferEncoding.SevenBit:
 296                                 return body;
 297                         case TransferEncoding.Base64:
 298                                 return Convert.ToBase64String (encoding.GetBytes (body), Base64FormattingOptions.InsertLineBreaks);
 299                         default:
 300                                 return ToQuotedPrintable (body, encoding);
 301                         }
 302                 }
 303
 304                 private string EncodeBody (AlternateView av)
 305                 {
 306                         //Encoding encoding = av.ContentType.CharSet != null ? Encoding.GetEncoding (av.ContentType.CharSet) : Encoding.UTF8;
 307
 308                         byte [] bytes = new byte [av.ContentStream.Length];
 309                         av.ContentStream.Read (bytes, 0, bytes.Length);
 310
 311                         // RFC 2045 encoding
 312                         switch (av.TransferEncoding) {
 313                         case TransferEncoding.SevenBit:
 314                                 return Encoding.ASCII.GetString (bytes);
 315                         case TransferEncoding.Base64:
 316                                 return Convert.ToBase64String (bytes, Base64FormattingOptions.InsertLineBreaks);
 317                         default:
 318                                 return ToQuotedPrintable (bytes);
 319                         }
 320                 }
 321
 322
 323                 private void EndSection (string section)
 324                 {
 325                         SendData (String.Format ("--{0}--", section));
 326                         SendData (string.Empty);
 327                 }
 328
 329                 private string GenerateBoundary ()
 330                 {
 331                         string output = GenerateBoundary (boundaryIndex);
 332                         boundaryIndex += 1;
 333                         return output;
 334                 }
 335
 336                 private static string GenerateBoundary (int index)
 337                 {
 338                         return String.Format ("--boundary_{0}_{1}", index, Guid.NewGuid ().ToString ("D"));
 339                 }
 340
 341                 private bool IsError (SmtpResponse status)
 342                 {
 343                         return ((int) status.StatusCode) >= 400;
 344                 }
 345
 346                 protected void OnSendCompleted (AsyncCompletedEventArgs e)
 347                 {
 348                         try {
 349                                 if (SendCompleted != null)
 350                                         SendCompleted (this, e);
 351                         } finally {
 352                                 worker = null;
 353                                 user_async_state = null;
 354                         }
 355                 }
 356
 357                 private void CheckCancellation ()
 358                 {
 359                         if (worker != null && worker.CancellationPending)
 360                                 throw new CancellationException ();
 361                 }
 362
 363                 private SmtpResponse Read () {
 364                         byte [] buffer = new byte [512];
 365                         int position = 0;
 366                         bool lastLine = false;
 367
 368                         do {
 369                                 CheckCancellation ();
 370
 371                                 int readLength = stream.Read (buffer, position, buffer.Length - position);
 372                                 if (readLength > 0) {
 373                                         int available = position + readLength - 1;
 374                                         if (available > 4 && (buffer [available] == '\n' || buffer [available] == '\r'))
 375                                                 for (int index = available - 3; ; index--) {
 376                                                         if (index < 0 || buffer [index] == '\n' || buffer [index] == '\r') {
 377                                                                 lastLine = buffer [index + 4] == ' ';
 378                                                                 break;
 379                                                         }
 380                                                 }
 381
 382                                         // move position
 383                                         position += readLength;
 384
 385                                         // check if buffer is full
 386                                         if (position == buffer.Length) {
 387                                                 byte [] newBuffer = new byte [buffer.Length * 2];
 388                                                 Array.Copy (buffer, 0, newBuffer, 0, buffer.Length);
 389                                                 buffer = newBuffer;
 390                                         }
 391                                 }
 392                                 else {
 393                                         break;
 394                                 }
 395                         } while (!lastLine);
 396
 397                         if (position > 0) {
 398                                 Encoding encoding = new ASCIIEncoding ();
 399
 400                                 string line = encoding.GetString (buffer, 0, position - 1);
 401
 402                                 // parse the line to the lastResponse object
 403                                 SmtpResponse response = SmtpResponse.Parse (line);
 404
 405                                 return response;
 406                         } else {
 407                                 throw new System.IO.IOException ("Connection closed");
 408                         }
 409                 }
 410
 411                 void ResetExtensions()
 412                 {
 413                         authMechs = AuthMechs.None;
 414                 }
 415
 416                 void ParseExtensions (string extens)
 417                 {
 418                         char[] delims = new char [1] { ' ' };
 419                         string[] parts = extens.Split ('\n');
 420
 421                         foreach (string part in parts) {
 422                                 if (part.Length < 4)
 423                                         continue;
 424
 425                                 string start = part.Substring (4);
 426                                 if (start.StartsWith ("AUTH ", StringComparison.Ordinal)) {
 427                                         string[] options = start.Split (delims);
 428                                         for (int k = 1; k < options.Length; k++) {
 429                                                 string option = options[k].Trim();
 430                                                 switch (option) {
 431                                                 case "CRAM-MD5":
 432                                                         authMechs |= AuthMechs.CramMD5;
 433                                                         break;
 434                                                 case "DIGEST-MD5":
 435                                                         authMechs |= AuthMechs.DigestMD5;
 436                                                         break;
 437                                                 case "GSSAPI":
 438                                                         authMechs |= AuthMechs.GssAPI;
 439                                                         break;
 440                                                 case "KERBEROS_V4":
 441                                                         authMechs |= AuthMechs.Kerberos4;
 442                                                         break;
 443                                                 case "LOGIN":
 444                                                         authMechs |= AuthMechs.Login;
 445                                                         break;
 446                                                 case "PLAIN":
 447                                                         authMechs |= AuthMechs.Plain;
 448                                                         break;
 449                                                 }
 450                                         }
 451                                 }
 452                         }
 453                 }
 454
 455                 public void Send (MailMessage message)
 456                 {
 457                         if (message == null)
 458                                 throw new ArgumentNullException ("message");
 459
 460                         if (deliveryMethod == SmtpDeliveryMethod.Network && (Host == null || Host.Trim ().Length == 0))
 461                                 throw new InvalidOperationException ("The SMTP host was not specified");
 462                         else if (deliveryMethod == SmtpDeliveryMethod.PickupDirectoryFromIis)
 463                                 throw new NotSupportedException("IIS delivery is not supported");
 464
 465                         if (port == 0)
 466                                 port = 25;
 467
 468                         // Block while sending
 469                         mutex.WaitOne ();
 470                         try {
 471                                 messageInProcess = message;
 472                                 if (deliveryMethod == SmtpDeliveryMethod.SpecifiedPickupDirectory)
 473                                         SendToFile (message);
 474                                 else
 475                                         SendInternal (message);
 476                         } catch (CancellationException) {
 477                                 // This exception is introduced for convenient cancellation process.
 478                         } catch (SmtpException) {
 479                                 throw;
 480                         } catch (Exception ex) {
 481                                 throw new SmtpException ("Message could not be sent.", ex);
 482                         } finally {
 483                                 // Release the mutex to allow other threads access
 484                                 mutex.ReleaseMutex ();
 485                                 messageInProcess = null;
 486                         }
 487                 }
 488
 489                 private void SendInternal (MailMessage message)
 490                 {
 491                         CheckCancellation ();
 492
 493                         try {
 494                                 client = new TcpClient (host, port);
 495                                 stream = client.GetStream ();
 496                                 // FIXME: this StreamWriter creation is bogus.
 497                                 // It expects as if a Stream were able to switch to SSL
 498                                 // mode (such behavior is only in Mainsoft Socket API).
 499                                 writer = new StreamWriter (stream);
 500                                 reader = new StreamReader (stream);
 501
 502                                 SendCore (message);
 503                         } finally {
 504                                 if (writer != null)
 505                                         writer.Close ();
 506                                 if (reader != null)
 507                                         reader.Close ();
 508                                 if (stream != null)
 509                                         stream.Close ();
 510                                 if (client != null)
 511                                         client.Close ();
 512                         }
 513                 }
 514
 515                 // FIXME: simple implementation, could be brushed up.
 516                 private void SendToFile (MailMessage message)
 517                 {
 518                         if (!Path.IsPathRooted (pickupDirectoryLocation))
 519                                 throw new SmtpException("Only absolute directories are allowed for pickup directory.");
 520
 521                         string filename = Path.Combine (pickupDirectoryLocation,
 522                                 Guid.NewGuid() + ".eml");
 523
 524                         try {
 525                                 writer = new StreamWriter(filename);
 526
 527                                 MailAddress from = message.From;
 528
 529                                 if (from == null)
 530                                         from = defaultFrom;
 531
 532                                 SendHeader (HeaderName.Date, DateTime.Now.ToString ("ddd, dd MMM yyyy HH':'mm':'ss zzz", DateTimeFormatInfo.InvariantInfo));
 533                                 SendHeader (HeaderName.From, from.ToString ());
 534                                 SendHeader (HeaderName.To, message.To.ToString ());
 535                                 if (message.CC.Count > 0)
 536                                         SendHeader (HeaderName.Cc, message.CC.ToString ());
 537                                 SendHeader (HeaderName.Subject, EncodeSubjectRFC2047 (message));
 538
 539                                 foreach (string s in message.Headers.AllKeys)
 540                                         SendHeader (s, message.Headers [s]);
 541
 542                                 AddPriorityHeader (message);
 543
 544                                 boundaryIndex = 0;
 545                                 if (message.Attachments.Count > 0)
 546                                         SendWithAttachments (message);
 547                                 else
 548                                         SendWithoutAttachments (message, null, false);
 549
 550
 551                         } finally {
 552                                 if (writer != null) writer.Close(); writer = null;
 553                         }
 554                 }
 555
 556                 private void SendCore (MailMessage message)
 557                 {
 558                         SmtpResponse status;
 559
 560                         status = Read ();
 561                         if (IsError (status))
 562                                 throw new SmtpException (status.StatusCode, status.Description);
 563
 564                         // EHLO
 565
 566                         // FIXME: parse the list of extensions so we don't bother wasting
 567                         // our time trying commands if they aren't supported.
 568                         status = SendCommand ("EHLO " + Dns.GetHostName ());
 569
 570                         if (IsError (status)) {
 571                                 status = SendCommand ("HELO " + Dns.GetHostName ());
 572
 573                                 if (IsError (status))
 574                                         throw new SmtpException (status.StatusCode, status.Description);
 575                         } else {
 576                                 // Parse ESMTP extensions
 577                                 string extens = status.Description;
 578
 579                                 if (extens != null)
 580                                         ParseExtensions (extens);
 581                         }
 582
 583                         if (enableSsl) {
 584                                 InitiateSecureConnection ();
 585                                 ResetExtensions();
 586                                 writer = new StreamWriter (stream);
 587                                 reader = new StreamReader (stream);
 588                                 status = SendCommand ("EHLO " + Dns.GetHostName ());
 589
 590                                 if (IsError (status)) {
 591                                         status = SendCommand ("HELO " + Dns.GetHostName ());
 592
 593                                         if (IsError (status))
 594                                                 throw new SmtpException (status.StatusCode, status.Description);
 595                                 } else {
 596                                         // Parse ESMTP extensions
 597                                         string extens = status.Description;
 598                                         if (extens != null)
 599                                                 ParseExtensions (extens);
 600                                 }
 601                         }
 602
 603                         if (authMechs != AuthMechs.None)
 604                                 Authenticate ();
 605
 606                         MailAddress from = message.From;
 607
 608                         if (from == null)
 609                                 from = defaultFrom;
 610
 611                         // MAIL FROM:
 612                         status = SendCommand ("MAIL FROM:<" + from.Address + '>');
 613                         if (IsError (status)) {
 614                                 throw new SmtpException (status.StatusCode, status.Description);
 615                         }
 616
 617                         // Send RCPT TO: for all recipients
 618                         List<SmtpFailedRecipientException> sfre = new List<SmtpFailedRecipientException> ();
 619
 620                         for (int i = 0; i < message.To.Count; i ++) {
 621                                 status = SendCommand ("RCPT TO:<" + message.To [i].Address + '>');
 622                                 if (IsError (status))
 623                                         sfre.Add (new SmtpFailedRecipientException (status.StatusCode, message.To [i].Address));
 624                         }
 625                         for (int i = 0; i < message.CC.Count; i ++) {
 626                                 status = SendCommand ("RCPT TO:<" + message.CC [i].Address + '>');
 627                                 if (IsError (status))
 628                                         sfre.Add (new SmtpFailedRecipientException (status.StatusCode, message.CC [i].Address));
 629                         }
 630                         for (int i = 0; i < message.Bcc.Count; i ++) {
 631                                 status = SendCommand ("RCPT TO:<" + message.Bcc [i].Address + '>');
 632                                 if (IsError (status))
 633                                         sfre.Add (new SmtpFailedRecipientException (status.StatusCode, message.Bcc [i].Address));
 634                         }
 635
 636 #if TARGET_JVM // List<T>.ToArray () is not supported
 637                         if (sfre.Count > 0) {
 638                                 SmtpFailedRecipientException[] xs = new SmtpFailedRecipientException[sfre.Count];
 639                                 sfre.CopyTo (xs);
 640                                 throw new SmtpFailedRecipientsException ("failed recipients", xs);
 641                         }
 642 #else
 643                         if (sfre.Count >0)
 644                                 throw new SmtpFailedRecipientsException ("failed recipients", sfre.ToArray ());
 645 #endif
 646
 647                         // DATA
 648                         status = SendCommand ("DATA");
 649                         if (IsError (status))
 650                                 throw new SmtpException (status.StatusCode, status.Description);
 651
 652                         // Send message headers
 653                         string dt = DateTime.Now.ToString ("ddd, dd MMM yyyy HH':'mm':'ss zzz", DateTimeFormatInfo.InvariantInfo);
 654                         // remove ':' from time zone offset (e.g. from "+01:00")
 655                         dt = dt.Remove (dt.Length - 3, 1);
 656                         SendHeader (HeaderName.Date, dt);
 657
 658                         SendHeader (HeaderName.From, EncodeAddress (from));
 659                         SendHeader (HeaderName.To, EncodeAddresses (message.To));
 660                         if (message.CC.Count > 0)
 661                                 SendHeader (HeaderName.Cc, EncodeAddresses (message.CC));
 662                         SendHeader (HeaderName.Subject, EncodeSubjectRFC2047 (message));
 663
 664                         string v = "normal";
 665
 666                         switch (message.Priority){
 667                         case MailPriority.Normal:
 668                                 v = "normal";
 669                                 break;
 670
 671                         case MailPriority.Low:
 672                                 v = "non-urgent";
 673                                 break;
 674
 675                         case MailPriority.High:
 676                                 v = "urgent";
 677                                 break;
 678                         }
 679                         SendHeader ("Priority", v);
 680                         if (message.Sender != null)
 681                                 SendHeader ("Sender", EncodeAddress (message.Sender));
 682                         if (message.ReplyToList.Count > 0)
 683                                 SendHeader ("ReplyTo", EncodeAddresses (message.ReplyToList));
 684
 685 #if NET_4_0
 686                         foreach (string s in message.Headers.AllKeys)
 687                                 SendHeader (s, ContentType.EncodeSubjectRFC2047 (message.Headers [s], message.HeadersEncoding));
 688 #else
 689                         foreach (string s in message.Headers.AllKeys)
 690                                 SendHeader (s, message.Headers [s]);
 691 #endif
 692
 693                         AddPriorityHeader (message);
 694
 695                         boundaryIndex = 0;
 696                         if (message.Attachments.Count > 0)
 697                                 SendWithAttachments (message);
 698                         else
 699                                 SendWithoutAttachments (message, null, false);
 700
 701                         SendDot ();
 702
 703                         status = Read ();
 704                         if (IsError (status))
 705                                 throw new SmtpException (status.StatusCode, status.Description);
 706
 707                         try {
 708                                 status = SendCommand ("QUIT");
 709                         } catch (System.IO.IOException) {
 710                                 // We excuse server for the rude connection closing as a response to QUIT
 711                         }
 712                 }
 713
 714                 public void Send (string from, string to, string subject, string body)
 715                 {
 716                         Send (new MailMessage (from, to, subject, body));
 717                 }
 718
 719                 private void SendDot()
 720                 {
 721                         writer.Write(".\r\n");
 722                         writer.Flush();
 723                 }
 724
 725                 private void SendData (string data)
 726                 {
 727                         if (String.IsNullOrEmpty (data)) {
 728                                 writer.Write("\r\n");
 729                                 writer.Flush();
 730                                 return;
 731                         }
 732
 733                         StringReader sr = new StringReader (data);
 734                         string line;
 735                         bool escapeDots = deliveryMethod == SmtpDeliveryMethod.Network;
 736                         while ((line = sr.ReadLine ()) != null) {
 737                                 CheckCancellation ();
 738
 739                                 if (escapeDots) {
 740                                         int i;
 741                                         for (i = 0; i < line.Length; i++) {
 742                                                 if (line[i] != '.')
 743                                                         break;
 744                                         }
 745                                         if (i > 0 && i == line.Length) {
 746                                                 line += ".";
 747                                         }
 748                                 }
 749                                 writer.Write (line);
 750                                 writer.Write ("\r\n");
 751                         }
 752                         writer.Flush ();
 753                 }
 754
 755                 public void SendAsync (MailMessage message, object userToken)
 756                 {
 757                         if (worker != null)
 758                                 throw new InvalidOperationException ("Another SendAsync operation is in progress");
 759
 760                         worker = new BackgroundWorker ();
 761                         worker.DoWork += delegate (object o, DoWorkEventArgs ea) {
 762                                 try {
 763                                         user_async_state = ea.Argument;
 764                                         Send (message);
 765                                 } catch (Exception ex) {
 766                                         ea.Result = ex;
 767                                         throw ex;
 768                                 }
 769                         };
 770                         worker.WorkerSupportsCancellation = true;
 771                         worker.RunWorkerCompleted += delegate (object o, RunWorkerCompletedEventArgs ea) {
 772                                 // Note that RunWorkerCompletedEventArgs.UserState cannot be used (LAMESPEC)
 773                                 OnSendCompleted (new AsyncCompletedEventArgs (ea.Error, ea.Cancelled, user_async_state));
 774                         };
 775                         worker.RunWorkerAsync (userToken);
 776                 }
 777
 778                 public void SendAsync (string from, string to, string subject, string body, object userToken)
 779                 {
 780                         SendAsync (new MailMessage (from, to, subject, body), userToken);
 781                 }
 782
 783                 public void SendAsyncCancel ()
 784                 {
 785                         if (worker == null)
 786                                 throw new InvalidOperationException ("SendAsync operation is not in progress");
 787                         worker.CancelAsync ();
 788                 }
 789
 790                 private void AddPriorityHeader (MailMessage message) {
 791                         switch (message.Priority) {
 792                         case MailPriority.High:
 793                                 SendHeader (HeaderName.Priority, "Urgent");
 794                                 SendHeader (HeaderName.Importance, "high");
 795                                 SendHeader (HeaderName.XPriority, "1");
 796                                 break;
 797                         case MailPriority.Low:
 798                                 SendHeader (HeaderName.Priority, "Non-Urgent");
 799                                 SendHeader (HeaderName.Importance, "low");
 800                                 SendHeader (HeaderName.XPriority, "5");
 801                                 break;
 802                         }
 803                 }
 804
 805                 private void SendSimpleBody (MailMessage message) {
 806                         SendHeader (HeaderName.ContentType, message.BodyContentType.ToString ());
 807                         if (message.ContentTransferEncoding != TransferEncoding.SevenBit)
 808                                 SendHeader (HeaderName.ContentTransferEncoding, GetTransferEncodingName (message.ContentTransferEncoding));
 809                         SendData (string.Empty);
 810
 811                         SendData (EncodeBody (message));
 812                 }
 813
 814                 private void SendBodylessSingleAlternate (AlternateView av) {
 815                         SendHeader (HeaderName.ContentType, av.ContentType.ToString ());
 816                         if (av.TransferEncoding != TransferEncoding.SevenBit)
 817                                 SendHeader (HeaderName.ContentTransferEncoding, GetTransferEncodingName (av.TransferEncoding));
 818                         SendData (string.Empty);
 819
 820                         SendData (EncodeBody (av));
 821                 }
 822
 823                 private void SendWithoutAttachments (MailMessage message, string boundary, bool attachmentExists)
 824                 {
 825                         if (message.Body == null && message.AlternateViews.Count == 1)
 826                                 SendBodylessSingleAlternate (message.AlternateViews [0]);
 827                         else if (message.AlternateViews.Count > 0)
 828                                 SendBodyWithAlternateViews (message, boundary, attachmentExists);
 829                         else
 830                                 SendSimpleBody (message);
 831                 }
 832
 833
 834                 private void SendWithAttachments (MailMessage message) {
 835                         string boundary = GenerateBoundary ();
 836
 837                         // first "multipart/mixed"
 838                         ContentType messageContentType = new ContentType ();
 839                         messageContentType.Boundary = boundary;
 840                         messageContentType.MediaType = "multipart/mixed";
 841                         messageContentType.CharSet = null;
 842
 843                         SendHeader (HeaderName.ContentType, messageContentType.ToString ());
 844                         SendData (String.Empty);
 845
 846                         // body section
 847                         Attachment body = null;
 848
 849                         if (message.AlternateViews.Count > 0)
 850                                 SendWithoutAttachments (message, boundary, true);
 851                         else {
 852                                 body = Attachment.CreateAttachmentFromString (message.Body, null, message.BodyEncoding, message.IsBodyHtml ? "text/html" : "text/plain");
 853                                 message.Attachments.Insert (0, body);
 854                         }
 855
 856                         try {
 857                                 SendAttachments (message, body, boundary);
 858                         } finally {
 859                                 if (body != null)
 860                                         message.Attachments.Remove (body);
 861                         }
 862
 863                         EndSection (boundary);
 864                 }
 865
 866                 private void SendBodyWithAlternateViews (MailMessage message, string boundary, bool attachmentExists)
 867                 {
 868                         AlternateViewCollection alternateViews = message.AlternateViews;
 869
 870                         string inner_boundary = GenerateBoundary ();
 871
 872                         ContentType messageContentType = new ContentType ();
 873                         messageContentType.Boundary = inner_boundary;
 874                         messageContentType.MediaType = "multipart/alternative";
 875
 876                         if (!attachmentExists) {
 877                                 SendHeader (HeaderName.ContentType, messageContentType.ToString ());
 878                                 SendData (String.Empty);
 879                         }
 880
 881                         // body section
 882                         AlternateView body = null;
 883                         if (message.Body != null) {
 884                                 body = AlternateView.CreateAlternateViewFromString (message.Body, message.BodyEncoding, message.IsBodyHtml ? "text/html" : "text/plain");
 885                                 alternateViews.Insert (0, body);
 886                                 StartSection (boundary, messageContentType);
 887                         }
 888
 889 try {
 890                         // alternate view sections
 891                         foreach (AlternateView av in alternateViews) {
 892
 893                                 string alt_boundary = null;
 894                                 ContentType contentType;
 895                                 if (av.LinkedResources.Count > 0) {
 896                                         alt_boundary = GenerateBoundary ();
 897                                         contentType = new ContentType ("multipart/related");
 898                                         contentType.Boundary = alt_boundary;
 899
 900                                         contentType.Parameters ["type"] = av.ContentType.ToString ();
 901                                         StartSection (inner_boundary, contentType);
 902                                         StartSection (alt_boundary, av.ContentType, av.TransferEncoding);
 903                                 } else {
 904                                         contentType = new ContentType (av.ContentType.ToString ());
 905                                         StartSection (inner_boundary, contentType, av.TransferEncoding);
 906                                 }
 907
 908                                 switch (av.TransferEncoding) {
 909                                 case TransferEncoding.Base64:
 910                                         byte [] content = new byte [av.ContentStream.Length];
 911                                         av.ContentStream.Read (content, 0, content.Length);
 912 #if TARGET_JVM
 913                                         SendData (Convert.ToBase64String (content));
 914 #else
 915                                             SendData (Convert.ToBase64String (content, Base64FormattingOptions.InsertLineBreaks));
 916 #endif
 917                                         break;
 918                                 case TransferEncoding.QuotedPrintable:
 919                                         byte [] bytes = new byte [av.ContentStream.Length];
 920                                         av.ContentStream.Read (bytes, 0, bytes.Length);
 921                                         SendData (ToQuotedPrintable (bytes));
 922                                         break;
 923                                 case TransferEncoding.SevenBit:
 924                                 case TransferEncoding.Unknown:
 925                                         content = new byte [av.ContentStream.Length];
 926                                         av.ContentStream.Read (content, 0, content.Length);
 927                                         SendData (Encoding.ASCII.GetString (content));
 928                                         break;
 929                                 }
 930
 931                                 if (av.LinkedResources.Count > 0) {
 932                                         SendLinkedResources (message, av.LinkedResources, alt_boundary);
 933                                         EndSection (alt_boundary);
 934                                 }
 935
 936                                 if (!attachmentExists)
 937                                         SendData (string.Empty);
 938                         }
 939
 940 } finally {
 941                         if (body != null)
 942                                 alternateViews.Remove (body);
 943 }
 944                         EndSection (inner_boundary);
 945                 }
 946
 947                 private void SendLinkedResources (MailMessage message, LinkedResourceCollection resources, string boundary)
 948                 {
 949                         foreach (LinkedResource lr in resources) {
 950                                 StartSection (boundary, lr.ContentType, lr.TransferEncoding, lr);
 951
 952                                 switch (lr.TransferEncoding) {
 953                                 case TransferEncoding.Base64:
 954                                         byte [] content = new byte [lr.ContentStream.Length];
 955                                         lr.ContentStream.Read (content, 0, content.Length);
 956 #if TARGET_JVM
 957                                         SendData (Convert.ToBase64String (content));
 958 #else
 959                                             SendData (Convert.ToBase64String (content, Base64FormattingOptions.InsertLineBreaks));
 960 #endif
 961                                         break;
 962                                 case TransferEncoding.QuotedPrintable:
 963                                         byte [] bytes = new byte [lr.ContentStream.Length];
 964                                         lr.ContentStream.Read (bytes, 0, bytes.Length);
 965                                         SendData (ToQuotedPrintable (bytes));
 966                                         break;
 967                                 case TransferEncoding.SevenBit:
 968                                 case TransferEncoding.Unknown:
 969                                         content = new byte [lr.ContentStream.Length];
 970                                         lr.ContentStream.Read (content, 0, content.Length);
 971                                         SendData (Encoding.ASCII.GetString (content));
 972                                         break;
 973                                 }
 974                         }
 975                 }
 976
 977                 private void SendAttachments (MailMessage message, Attachment body, string boundary) {
 978                         foreach (Attachment att in message.Attachments) {
 979                                 ContentType contentType = new ContentType (att.ContentType.ToString ());
 980                                 if (att.Name != null) {
 981                                         contentType.Name = att.Name;
 982                                         if (att.NameEncoding != null)
 983                                                 contentType.CharSet = att.NameEncoding.HeaderName;
 984                                         att.ContentDisposition.FileName = att.Name;
 985                                 }
 986                                 StartSection (boundary, contentType, att.TransferEncoding, att == body ? null : att.ContentDisposition);
 987
 988                                 byte [] content = new byte [att.ContentStream.Length];
 989                                 att.ContentStream.Read (content, 0, content.Length);
 990                                 switch (att.TransferEncoding) {
 991                                 case TransferEncoding.Base64:
 992 #if TARGET_JVM
 993                                         SendData (Convert.ToBase64String (content));
 994 #else
 995                                         SendData (Convert.ToBase64String (content, Base64FormattingOptions.InsertLineBreaks));
 996 #endif
 997                                         break;
 998                                 case TransferEncoding.QuotedPrintable:
 999                                         SendData (ToQuotedPrintable (content));
1000                                         break;
1001                                 case TransferEncoding.SevenBit:
1002                                 case TransferEncoding.Unknown:
1003                                         SendData (Encoding.ASCII.GetString (content));
1004                                         break;
1005                                 }
1006
1007                                 SendData (string.Empty);
1008                         }
1009                 }
1010
1011                 private SmtpResponse SendCommand (string command)
1012                 {
1013                         writer.Write (command);
1014                         // Certain SMTP servers will reject mail sent with unix line-endings; see http://cr.yp.to/docs/smtplf.html
1015                         writer.Write ("\r\n");
1016                         writer.Flush ();
1017                         return Read ();
1018                 }
1019
1020                 private void SendHeader (string name, string value)
1021                 {
1022                         SendData (String.Format ("{0}: {1}", name, value));
1023                 }
1024
1025                 private void StartSection (string section, ContentType sectionContentType)
1026                 {
1027                         SendData (String.Format ("--{0}", section));
1028                         SendHeader ("content-type", sectionContentType.ToString ());
1029                         SendData (string.Empty);
1030                 }
1031
1032                 private void StartSection (string section, ContentType sectionContentType,TransferEncoding transferEncoding)
1033                 {
1034                         SendData (String.Format ("--{0}", section));
1035                         SendHeader ("content-type", sectionContentType.ToString ());
1036                         SendHeader ("content-transfer-encoding", GetTransferEncodingName (transferEncoding));
1037                         SendData (string.Empty);
1038                 }
1039
1040                 private void StartSection(string section, ContentType sectionContentType, TransferEncoding transferEncoding, LinkedResource lr)
1041                 {
1042                         SendData (String.Format("--{0}", section));
1043                         SendHeader ("content-type", sectionContentType.ToString ());
1044                         SendHeader ("content-transfer-encoding", GetTransferEncodingName (transferEncoding));
1045
1046                         if (lr.ContentId != null && lr.ContentId.Length > 0)
1047                                 SendHeader("content-ID", "<" + lr.ContentId + ">");
1048
1049                         SendData (string.Empty);
1050                 }
1051
1052                 private void StartSection (string section, ContentType sectionContentType, TransferEncoding transferEncoding, ContentDisposition contentDisposition) {
1053                         SendData (String.Format ("--{0}", section));
1054                         SendHeader ("content-type", sectionContentType.ToString ());
1055                         SendHeader ("content-transfer-encoding", GetTransferEncodingName (transferEncoding));
1056                         if (contentDisposition != null)
1057                                 SendHeader ("content-disposition", contentDisposition.ToString ());
1058                         SendData (string.Empty);
1059                 }
1060
1061                 // use proper encoding to escape input
1062                 private string ToQuotedPrintable (string input, Encoding enc)
1063                 {
1064                         byte [] bytes = enc.GetBytes (input);
1065                         return ToQuotedPrintable (bytes);
1066                 }
1067
1068                 private string ToQuotedPrintable (byte [] bytes)
1069                 {
1070                         StringWriter writer = new StringWriter ();
1071                         int charsInLine = 0;
1072                         int curLen;
1073                         StringBuilder sb = new StringBuilder("=", 3);
1074                         byte equalSign = (byte)'=';
1075                         char c = (char)0;
1076
1077                         foreach (byte i in bytes) {
1078                                 if (i > 127 || i == equalSign) {
1079                                         sb.Length = 1;
1080                                         sb.Append(Convert.ToString (i, 16).ToUpperInvariant ());
1081                                         curLen = 3;
1082                                 } else {
1083                                         c = Convert.ToChar (i);
1084                                         if (c == '\r' || c == '\n') {
1085                                                 writer.Write (c);
1086                                                 charsInLine = 0;
1087                                                 continue;
1088                                         }
1089                                         curLen = 1;
1090                                 }
1091
1092                                 charsInLine += curLen;
1093                                 if (charsInLine > 75) {
1094                                         writer.Write ("=\r\n");
1095                                         charsInLine = curLen;
1096                                 }
1097                                 if (curLen == 1)
1098                                         writer.Write (c);
1099                                 else
1100                                         writer.Write (sb.ToString ());
1101                         }
1102
1103                         return writer.ToString ();
1104                 }
1105                 private static string GetTransferEncodingName (TransferEncoding encoding)
1106                 {
1107                         switch (encoding) {
1108                         case TransferEncoding.QuotedPrintable:
1109                                 return "quoted-printable";
1110                         case TransferEncoding.SevenBit:
1111                                 return "7bit";
1112                         case TransferEncoding.Base64:
1113                                 return "base64";
1114                         }
1115                         return "unknown";
1116                 }
1117
1118 #if SECURITY_DEP
1119                 RemoteCertificateValidationCallback callback = delegate (object sender,
1120                                                                          X509Certificate certificate,
1121                                                                          X509Chain chain,
1122                                                                          SslPolicyErrors sslPolicyErrors) {
1123                         // honor any exciting callback defined on ServicePointManager
1124                         if (ServicePointManager.ServerCertificateValidationCallback != null)
1125                                 return ServicePointManager.ServerCertificateValidationCallback (sender, certificate, chain, sslPolicyErrors);
1126                         // otherwise provide our own
1127                         if (sslPolicyErrors != SslPolicyErrors.None)
1128                                 throw new InvalidOperationException ("SSL authentication error: " + sslPolicyErrors);
1129                         return true;
1130                         };
1131 #endif
1132
1133                 private void InitiateSecureConnection () {
1134                         SmtpResponse response = SendCommand ("STARTTLS");
1135
1136                         if (IsError (response)) {
1137                                 throw new SmtpException (SmtpStatusCode.GeneralFailure, "Server does not support secure connections.");
1138                         }
1139
1140 #if TARGET_JVM
1141                         ((NetworkStream) stream).ChangeToSSLSocket ();
1142 #elif SECURITY_DEP
1143                         SslStream sslStream = new SslStream (stream, false, callback, null);
1144                         CheckCancellation ();
1145                         sslStream.AuthenticateAsClient (Host, this.ClientCertificates, SslProtocols.Default, false);
1146                         stream = sslStream;
1147
1148 #else
1149                         throw new SystemException ("You are using an incomplete System.dll build");
1150 #endif
1151                 }
1152
1153                 void Authenticate ()
1154                 {
1155                         string user = null, pass = null;
1156
1157                         if (UseDefaultCredentials) {
1158                                 user = CredentialCache.DefaultCredentials.GetCredential (new System.Uri ("smtp://" + host), "basic").UserName;
1159                                 pass =  CredentialCache.DefaultCredentials.GetCredential (new System.Uri ("smtp://" + host), "basic").Password;
1160                         } else if (Credentials != null) {
1161                                 user = Credentials.GetCredential (host, port, "smtp").UserName;
1162                                 pass = Credentials.GetCredential (host, port, "smtp").Password;
1163                         } else {
1164                                 return;
1165                         }
1166
1167                         Authenticate (user, pass);
1168                 }
1169
1170                 void Authenticate (string Username, string Password)
1171                 {
1172                         // FIXME: use the proper AuthMech
1173                         SmtpResponse status = SendCommand ("AUTH LOGIN");
1174                         if (((int) status.StatusCode) != 334) {
1175                                 throw new SmtpException (status.StatusCode, status.Description);
1176                         }
1177
1178                         status = SendCommand (Convert.ToBase64String (Encoding.ASCII.GetBytes (Username)));
1179                         if (((int) status.StatusCode) != 334) {
1180                                 throw new SmtpException (status.StatusCode, status.Description);
1181                         }
1182
1183                         status = SendCommand (Convert.ToBase64String (Encoding.ASCII.GetBytes (Password)));
1184                         if (IsError (status)) {
1185                                 throw new SmtpException (status.StatusCode, status.Description);
1186                         }
1187                 }
1188
1189                 #endregion // Methods
1190
1191                 // The HeaderName struct is used to store constant string values representing mail headers.
1192                 private struct HeaderName {
1193                         public const string ContentTransferEncoding = "Content-Transfer-Encoding";
1194                         public const string ContentType = "Content-Type";
1195                         public const string Bcc = "Bcc";
1196                         public const string Cc = "Cc";
1197                         public const string From = "From";
1198                         public const string Subject = "Subject";
1199                         public const string To = "To";
1200                         public const string MimeVersion = "MIME-Version";
1201                         public const string MessageId = "Message-ID";
1202                         public const string Priority = "Priority";
1203                         public const string Importance = "Importance";
1204                         public const string XPriority = "X-Priority";
1205                         public const string Date = "Date";
1206                 }
1207
1208                 // This object encapsulates the status code and description of an SMTP response.
1209                 private struct SmtpResponse {
1210                         public SmtpStatusCode StatusCode;
1211                         public string Description;
1212
1213                         public static SmtpResponse Parse (string line) {
1214                                 SmtpResponse response = new SmtpResponse ();
1215
1216                                 if (line.Length < 4)
1217                                         throw new SmtpException ("Response is to short " +
1218                                                                  line.Length + ".");
1219
1220                                 if ((line [3] != ' ') && (line [3] != '-'))
1221                                         throw new SmtpException ("Response format is wrong.(" +
1222                                                                  line + ")");
1223
1224                                 // parse the response code
1225                                 response.StatusCode = (SmtpStatusCode) Int32.Parse (line.Substring (0, 3));
1226
1227                                 // set the raw response
1228                                 response.Description = line;
1229
1230                                 return response;
1231                         }
1232                 }
1233         }
1234
1235         class CCredentialsByHost : ICredentialsByHost
1236         {
1237                 public CCredentialsByHost (string userName, string password) {
1238                         this.userName = userName;
1239                         this.password = password;
1240                 }
1241
1242                 public NetworkCredential GetCredential (string host, int port, string authenticationType) {
1243                         return new NetworkCredential (userName, password);
1244                 }
1245
1246                 private string userName;
1247                 private string password;
1248         }
1249 }
1250
1251 #endif // NET_2_0