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