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 #if MONO_SECURITY_ALIAS
  33 extern alias MonoSecurity;
  34 #endif
  35 #if MONO_X509_ALIAS
  36 extern alias PrebuiltSystem;
  37 #endif
  38
  39 #if MONO_SECURITY_ALIAS
  40 using MSI = MonoSecurity::Mono.Security.Interface;
  41 #else
  42 using MSI = Mono.Security.Interface;
  43 #endif
  44 #if MONO_X509_ALIAS
  45 using X509CertificateCollection = PrebuiltSystem::System.Security.Cryptography.X509Certificates.X509CertificateCollection;
  46 #else
  47 using X509CertificateCollection = System.Security.Cryptography.X509Certificates.X509CertificateCollection;
  48 #endif
  49 using System.Security.Cryptography.X509Certificates;
  50 #endif
  51
  52 using System;
  53 using System.Collections.Generic;
  54 using System.ComponentModel;
  55 using System.Globalization;
  56 using System.IO;
  57 using System.Net;
  58 using System.Net.Mime;
  59 using System.Net.Sockets;
  60 using System.Text;
  61 using System.Threading;
  62 using System.Net.Configuration;
  63 using System.Configuration;
  64 using System.Net.Security;
  65 using System.Security.Authentication;
  66 using System.Threading.Tasks;
  67 using Mono.Net.Security;
  68
  69 namespace System.Net.Mail {
  70         [Obsolete ("SmtpClient and its network of types are poorly designed, we strongly recommend you use https://github.com/jstedfast/MailKit and https://github.com/jstedfast/MimeKit instead")]
  71         public class SmtpClient
  72         : IDisposable
  73         {
  74                 #region Fields
  75
  76                 string host;
  77                 int port;
  78                 int timeout = 100000;
  79                 ICredentialsByHost credentials;
  80                 string pickupDirectoryLocation;
  81                 SmtpDeliveryMethod deliveryMethod;
  82                 bool enableSsl;
  83 #if SECURITY_DEP
  84                 X509CertificateCollection clientCertificates;
  85 #endif
  86
  87                 TcpClient client;
  88                 Stream stream;
  89                 StreamWriter writer;
  90                 StreamReader reader;
  91                 int boundaryIndex;
  92                 MailAddress defaultFrom;
  93
  94                 MailMessage messageInProcess;
  95
  96                 BackgroundWorker worker;
  97                 object user_async_state;
  98
  99                 [Flags]
 100                 enum AuthMechs {
 101                         None        = 0,
 102                         Login       = 0x01,
 103                         Plain       = 0x02,
 104                 }
 105
 106                 class CancellationException : Exception
 107                 {
 108                 }
 109
 110                 AuthMechs authMechs;
 111                 Mutex mutex = new Mutex ();
 112
 113                 #endregion // Fields
 114
 115                 #region Constructors
 116
 117                 public SmtpClient ()
 118                         : this (null, 0)
 119                 {
 120                 }
 121
 122                 public SmtpClient (string host)
 123                         : this (host, 0)
 124                 {
 125                 }
 126
 127                 public SmtpClient (string host, int port) {
 128 #if CONFIGURATION_DEP
 129                         SmtpSection cfg = (SmtpSection) ConfigurationManager.GetSection ("system.net/mailSettings/smtp");
 130
 131                         if (cfg != null) {
 132                                 this.host = cfg.Network.Host;
 133                                 this.port = cfg.Network.Port;
 134                                 this.enableSsl = cfg.Network.EnableSsl;
 135                                 TargetName = cfg.Network.TargetName;
 136                                 if (this.TargetName == null)
 137                                         TargetName = "SMTPSVC/" + (host != null ? host : "");
 138
 139
 140                                 if (cfg.Network.UserName != null) {
 141                                         string password = String.Empty;
 142
 143                                         if (cfg.Network.Password != null)
 144                                                 password = cfg.Network.Password;
 145
 146                                         Credentials = new CCredentialsByHost (cfg.Network.UserName, password);
 147                                 }
 148
 149                                 if (!String.IsNullOrEmpty (cfg.From))
 150                                         defaultFrom = new MailAddress (cfg.From);
 151                         }
 152 #else
 153                         // Just to eliminate the warning, this codepath does not end up in production.
 154                         defaultFrom = null;
 155 #endif
 156
 157                         if (!String.IsNullOrEmpty (host))
 158                                 this.host = host;
 159
 160                         if (port != 0)
 161                                 this.port = port;
 162                         else if (this.port == 0)
 163                                 this.port = 25;
 164                 }
 165
 166                 #endregion // Constructors
 167
 168                 #region Properties
 169
 170 #if SECURITY_DEP
 171                 [MonoTODO("Client certificates not used")]
 172                 public X509CertificateCollection ClientCertificates {
 173                         get {
 174                                 if (clientCertificates == null)
 175                                         clientCertificates = new X509CertificateCollection ();
 176                                 return clientCertificates;
 177                         }
 178                 }
 179 #endif
 180
 181                 public
 182                 string TargetName { get; set; }
 183
 184                 public ICredentialsByHost Credentials {
 185                         get { return credentials; }
 186                         set {
 187                                 CheckState ();
 188                                 credentials = value;
 189                         }
 190                 }
 191
 192                 public SmtpDeliveryMethod DeliveryMethod {
 193                         get { return deliveryMethod; }
 194                         set {
 195                                 CheckState ();
 196                                 deliveryMethod = value;
 197                         }
 198                 }
 199
 200                 public bool EnableSsl {
 201                         get { return enableSsl; }
 202                         set {
 203                                 CheckState ();
 204                                 enableSsl = value;
 205                         }
 206                 }
 207
 208                 public string Host {
 209                         get { return host; }
 210                         set {
 211                                 if (value == null)
 212                                         throw new ArgumentNullException ("value");
 213                                 if (value.Length == 0)
 214                                         throw new ArgumentException ("An empty string is not allowed.", "value");
 215                                 CheckState ();
 216                                 host = value;
 217                         }
 218                 }
 219
 220                 public string PickupDirectoryLocation {
 221                         get { return pickupDirectoryLocation; }
 222                         set { pickupDirectoryLocation = value; }
 223                 }
 224
 225                 public int Port {
 226                         get { return port; }
 227                         set {
 228                                 if (value <= 0)
 229                                         throw new ArgumentOutOfRangeException ("value");
 230                                 CheckState ();
 231                                 port = value;
 232                         }
 233                 }
 234
 235                 [MonoTODO]
 236                 public ServicePoint ServicePoint {
 237                         get { throw new NotImplementedException (); }
 238                 }
 239
 240                 public int Timeout {
 241                         get { return timeout; }
 242                         set {
 243                                 if (value < 0)
 244                                         throw new ArgumentOutOfRangeException ("value");
 245                                 CheckState ();
 246                                 timeout = value;
 247                         }
 248                 }
 249
 250                 public bool UseDefaultCredentials {
 251                         get { return false; }
 252                         [MonoNotSupported ("no DefaultCredential support in Mono")]
 253                         set {
 254                                 if (value)
 255                                         throw new NotImplementedException ("Default credentials are not supported");
 256                                 CheckState ();
 257                         }
 258                 }
 259
 260                 #endregion // Properties
 261
 262                 #region Events
 263
 264                 public event SendCompletedEventHandler SendCompleted;
 265
 266                 #endregion // Events
 267
 268                 #region Methods
 269                 public void Dispose ()
 270                 {
 271                         Dispose (true);
 272                 }
 273
 274                 [MonoTODO ("Does nothing at the moment.")]
 275                 protected virtual void Dispose (bool disposing)
 276                 {
 277                         // TODO: We should close all the connections and abort any async operations here
 278                 }
 279                 private void CheckState ()
 280                 {
 281                         if (messageInProcess != null)
 282                                 throw new InvalidOperationException ("Cannot set Timeout while Sending a message");
 283                 }
 284
 285                 private static string EncodeAddress(MailAddress address)
 286                 {
 287                         if (!String.IsNullOrEmpty (address.DisplayName)) {
 288                                 string encodedDisplayName = MailMessage.EncodeSubjectRFC2047 (address.DisplayName, Encoding.UTF8);
 289                                 return "\"" + encodedDisplayName + "\" <" + address.Address + ">";
 290                         }
 291                         return address.ToString ();
 292                 }
 293
 294                 private static string EncodeAddresses(MailAddressCollection addresses)
 295                 {
 296                         StringBuilder sb = new StringBuilder();
 297                         bool first = true;
 298                         foreach (MailAddress address in addresses) {
 299                                 if (!first) {
 300                                         sb.Append(", ");
 301                                 }
 302                                 sb.Append(EncodeAddress(address));
 303                                 first = false;
 304                         }
 305                         return sb.ToString();
 306                 }
 307
 308                 private string EncodeSubjectRFC2047 (MailMessage message)
 309                 {
 310                         return MailMessage.EncodeSubjectRFC2047 (message.Subject, message.SubjectEncoding);
 311                 }
 312
 313                 private string EncodeBody (MailMessage message)
 314                 {
 315                         string body = message.Body;
 316                         Encoding encoding = message.BodyEncoding;
 317                         // RFC 2045 encoding
 318                         switch (message.ContentTransferEncoding) {
 319                         case TransferEncoding.SevenBit:
 320                                 return body;
 321                         case TransferEncoding.Base64:
 322                                 return Convert.ToBase64String (encoding.GetBytes (body), Base64FormattingOptions.InsertLineBreaks);
 323                         default:
 324                                 return ToQuotedPrintable (body, encoding);
 325                         }
 326                 }
 327
 328                 private string EncodeBody (AlternateView av)
 329                 {
 330                         //Encoding encoding = av.ContentType.CharSet != null ? Encoding.GetEncoding (av.ContentType.CharSet) : Encoding.UTF8;
 331
 332                         byte [] bytes = new byte [av.ContentStream.Length];
 333                         av.ContentStream.Read (bytes, 0, bytes.Length);
 334
 335                         // RFC 2045 encoding
 336                         switch (av.TransferEncoding) {
 337                         case TransferEncoding.SevenBit:
 338                                 return Encoding.ASCII.GetString (bytes);
 339                         case TransferEncoding.Base64:
 340                                 return Convert.ToBase64String (bytes, Base64FormattingOptions.InsertLineBreaks);
 341                         default:
 342                                 return ToQuotedPrintable (bytes);
 343                         }
 344                 }
 345
 346
 347                 private void EndSection (string section)
 348                 {
 349                         SendData (String.Format ("--{0}--", section));
 350                         SendData (string.Empty);
 351                 }
 352
 353                 private string GenerateBoundary ()
 354                 {
 355                         string output = GenerateBoundary (boundaryIndex);
 356                         boundaryIndex += 1;
 357                         return output;
 358                 }
 359
 360                 private static string GenerateBoundary (int index)
 361                 {
 362                         return String.Format ("--boundary_{0}_{1}", index, Guid.NewGuid ().ToString ("D"));
 363                 }
 364
 365                 private bool IsError (SmtpResponse status)
 366                 {
 367                         return ((int) status.StatusCode) >= 400;
 368                 }
 369
 370                 protected void OnSendCompleted (AsyncCompletedEventArgs e)
 371                 {
 372                         try {
 373                                 if (SendCompleted != null)
 374                                         SendCompleted (this, e);
 375                         } finally {
 376                                 worker = null;
 377                                 user_async_state = null;
 378                         }
 379                 }
 380
 381                 private void CheckCancellation ()
 382                 {
 383                         if (worker != null && worker.CancellationPending)
 384                                 throw new CancellationException ();
 385                 }
 386
 387                 private SmtpResponse Read () {
 388                         byte [] buffer = new byte [512];
 389                         int position = 0;
 390                         bool lastLine = false;
 391
 392                         do {
 393                                 CheckCancellation ();
 394
 395                                 int readLength = stream.Read (buffer, position, buffer.Length - position);
 396                                 if (readLength > 0) {
 397                                         int available = position + readLength - 1;
 398                                         if (available > 4 && (buffer [available] == '\n' || buffer [available] == '\r'))
 399                                                 for (int index = available - 3; ; index--) {
 400                                                         if (index < 0 || buffer [index] == '\n' || buffer [index] == '\r') {
 401                                                                 lastLine = buffer [index + 4] == ' ';
 402                                                                 break;
 403                                                         }
 404                                                 }
 405
 406                                         // move position
 407                                         position += readLength;
 408
 409                                         // check if buffer is full
 410                                         if (position == buffer.Length) {
 411                                                 byte [] newBuffer = new byte [buffer.Length * 2];
 412                                                 Array.Copy (buffer, 0, newBuffer, 0, buffer.Length);
 413                                                 buffer = newBuffer;
 414                                         }
 415                                 }
 416                                 else {
 417                                         break;
 418                                 }
 419                         } while (!lastLine);
 420
 421                         if (position > 0) {
 422                                 Encoding encoding = new ASCIIEncoding ();
 423
 424                                 string line = encoding.GetString (buffer, 0, position - 1);
 425
 426                                 // parse the line to the lastResponse object
 427                                 SmtpResponse response = SmtpResponse.Parse (line);
 428
 429                                 return response;
 430                         } else {
 431                                 throw new System.IO.IOException ("Connection closed");
 432                         }
 433                 }
 434
 435                 void ResetExtensions()
 436                 {
 437                         authMechs = AuthMechs.None;
 438                 }
 439
 440                 void ParseExtensions (string extens)
 441                 {
 442                         string[] parts = extens.Split ('\n');
 443
 444                         foreach (string part in parts) {
 445                                 if (part.Length < 4)
 446                                         continue;
 447
 448                                 string start = part.Substring (4);
 449                                 if (start.StartsWith ("AUTH ", StringComparison.Ordinal)) {
 450                                         string[] options = start.Split (' ');
 451                                         for (int k = 1; k < options.Length; k++) {
 452                                                 string option = options[k].Trim();
 453                                                 // GSSAPI, KERBEROS_V4, NTLM not supported
 454                                                 switch (option) {
 455                                                 /*
 456                                                 case "CRAM-MD5":
 457                                                         authMechs |= AuthMechs.CramMD5;
 458                                                         break;
 459                                                 case "DIGEST-MD5":
 460                                                         authMechs |= AuthMechs.DigestMD5;
 461                                                         break;
 462                                                 */
 463                                                 case "LOGIN":
 464                                                         authMechs |= AuthMechs.Login;
 465                                                         break;
 466                                                 case "PLAIN":
 467                                                         authMechs |= AuthMechs.Plain;
 468                                                         break;
 469                                                 }
 470                                         }
 471                                 }
 472                         }
 473                 }
 474
 475                 public void Send (MailMessage message)
 476                 {
 477                         if (message == null)
 478                                 throw new ArgumentNullException ("message");
 479
 480                         if (deliveryMethod == SmtpDeliveryMethod.Network && (Host == null || Host.Trim ().Length == 0))
 481                                 throw new InvalidOperationException ("The SMTP host was not specified");
 482                         else if (deliveryMethod == SmtpDeliveryMethod.PickupDirectoryFromIis)
 483                                 throw new NotSupportedException("IIS delivery is not supported");
 484
 485                         if (port == 0)
 486                                 port = 25;
 487
 488                         // Block while sending
 489                         mutex.WaitOne ();
 490                         try {
 491                                 messageInProcess = message;
 492                                 if (deliveryMethod == SmtpDeliveryMethod.SpecifiedPickupDirectory)
 493                                         SendToFile (message);
 494                                 else
 495                                         SendInternal (message);
 496                         } catch (CancellationException) {
 497                                 // This exception is introduced for convenient cancellation process.
 498                         } catch (SmtpException) {
 499                                 throw;
 500                         } catch (Exception ex) {
 501                                 throw new SmtpException ("Message could not be sent.", ex);
 502                         } finally {
 503                                 // Release the mutex to allow other threads access
 504                                 mutex.ReleaseMutex ();
 505                                 messageInProcess = null;
 506                         }
 507                 }
 508
 509                 private void SendInternal (MailMessage message)
 510                 {
 511                         CheckCancellation ();
 512
 513                         try {
 514                                 client = new TcpClient (host, port);
 515                                 stream = client.GetStream ();
 516                                 // FIXME: this StreamWriter creation is bogus.
 517                                 // It expects as if a Stream were able to switch to SSL
 518                                 // mode (such behavior is only in Mainsoft Socket API).
 519                                 writer = new StreamWriter (stream);
 520                                 reader = new StreamReader (stream);
 521
 522                                 SendCore (message);
 523                         } finally {
 524                                 if (writer != null)
 525                                         writer.Close ();
 526                                 if (reader != null)
 527                                         reader.Close ();
 528                                 if (stream != null)
 529                                         stream.Close ();
 530                                 if (client != null)
 531                                         client.Close ();
 532                         }
 533                 }
 534
 535                 // FIXME: simple implementation, could be brushed up.
 536                 private void SendToFile (MailMessage message)
 537                 {
 538                         if (!Path.IsPathRooted (pickupDirectoryLocation))
 539                                 throw new SmtpException("Only absolute directories are allowed for pickup directory.");
 540
 541                         string filename = Path.Combine (pickupDirectoryLocation,
 542                                 Guid.NewGuid() + ".eml");
 543
 544                         try {
 545                                 writer = new StreamWriter(filename);
 546
 547                                 // FIXME: See how Microsoft fixed the bug about envelope senders, and how it actually represents the info in .eml file headers
 548                                 //        For all we know, defaultFrom may be the envelope sender
 549                                 // For now, we are no worse than some versions of .NET
 550                                 MailAddress from = message.From;
 551                                 if (from == null)
 552                                         from = defaultFrom;
 553
 554                                 string dt = DateTime.Now.ToString("ddd, dd MMM yyyy HH':'mm':'ss zzz", DateTimeFormatInfo.InvariantInfo);
 555                                 // remove ':' from time zone offset (e.g. from "+01:00")
 556                                 dt = dt.Remove(dt.Length - 3, 1);
 557                                 SendHeader(HeaderName.Date, dt);
 558
 559                                 SendHeader (HeaderName.From, EncodeAddress(from));
 560                                 SendHeader (HeaderName.To, EncodeAddresses(message.To));
 561                                 if (message.CC.Count > 0)
 562                                         SendHeader (HeaderName.Cc, EncodeAddresses(message.CC));
 563                                 SendHeader (HeaderName.Subject, EncodeSubjectRFC2047 (message));
 564
 565                                 foreach (string s in message.Headers.AllKeys)
 566                                         SendHeader (s, message.Headers [s]);
 567
 568                                 AddPriorityHeader (message);
 569
 570                                 boundaryIndex = 0;
 571                                 if (message.Attachments.Count > 0)
 572                                         SendWithAttachments (message);
 573                                 else
 574                                         SendWithoutAttachments (message, null, false);
 575
 576
 577                         } finally {
 578                                 if (writer != null) writer.Close(); writer = null;
 579                         }
 580                 }
 581
 582                 private void SendCore (MailMessage message)
 583                 {
 584                         SmtpResponse status;
 585
 586                         status = Read ();
 587                         if (IsError (status))
 588                                 throw new SmtpException (status.StatusCode, status.Description);
 589
 590                         // EHLO
 591
 592                         // FIXME: parse the list of extensions so we don't bother wasting
 593                         // our time trying commands if they aren't supported.
 594
 595                         // get the host name (not fully qualified)
 596                         string fqdn = Dns.GetHostName ();
 597                         try {
 598                                 // we'll try for the fully qualified name - ref: bug #33551
 599                                 fqdn = Dns.GetHostEntry (fqdn).HostName;
 600                         }
 601                         catch (SocketException) {
 602                                 // we could not resolve our name but will continue with the partial name
 603                                 // IOW we won't fail to send email because of this - ref: bug #37246
 604                         }
 605                         status = SendCommand ("EHLO " + fqdn);
 606
 607                         if (IsError (status)) {
 608                                 status = SendCommand ("HELO " + fqdn);
 609
 610                                 if (IsError (status))
 611                                         throw new SmtpException (status.StatusCode, status.Description);
 612                         } else {
 613                                 // Parse ESMTP extensions
 614                                 string extens = status.Description;
 615
 616                                 if (extens != null)
 617                                         ParseExtensions (extens);
 618                         }
 619
 620                         if (enableSsl) {
 621                                 InitiateSecureConnection ();
 622                                 ResetExtensions();
 623                                 writer = new StreamWriter (stream);
 624                                 reader = new StreamReader (stream);
 625                                 status = SendCommand ("EHLO " + fqdn);
 626
 627                                 if (IsError (status)) {
 628                                         status = SendCommand ("HELO " + fqdn);
 629
 630                                         if (IsError (status))
 631                                                 throw new SmtpException (status.StatusCode, status.Description);
 632                                 } else {
 633                                         // Parse ESMTP extensions
 634                                         string extens = status.Description;
 635                                         if (extens != null)
 636                                                 ParseExtensions (extens);
 637                                 }
 638                         }
 639
 640                         if (authMechs != AuthMechs.None)
 641                                 Authenticate ();
 642
 643                         // The envelope sender: use 'Sender:' in preference of 'From:'
 644                         MailAddress sender = message.Sender;
 645                         if (sender == null)
 646                                 sender = message.From;
 647                         if (sender == null)
 648                                 sender = defaultFrom;
 649
 650                         // MAIL FROM:
 651                         status = SendCommand ("MAIL FROM:<" + sender.Address + '>');
 652                         if (IsError (status)) {
 653                                 throw new SmtpException (status.StatusCode, status.Description);
 654                         }
 655
 656                         // Send RCPT TO: for all recipients
 657                         List<SmtpFailedRecipientException> sfre = new List<SmtpFailedRecipientException> ();
 658
 659                         for (int i = 0; i < message.To.Count; i ++) {
 660                                 status = SendCommand ("RCPT TO:<" + message.To [i].Address + '>');
 661                                 if (IsError (status))
 662                                         sfre.Add (new SmtpFailedRecipientException (status.StatusCode, message.To [i].Address));
 663                         }
 664                         for (int i = 0; i < message.CC.Count; i ++) {
 665                                 status = SendCommand ("RCPT TO:<" + message.CC [i].Address + '>');
 666                                 if (IsError (status))
 667                                         sfre.Add (new SmtpFailedRecipientException (status.StatusCode, message.CC [i].Address));
 668                         }
 669                         for (int i = 0; i < message.Bcc.Count; i ++) {
 670                                 status = SendCommand ("RCPT TO:<" + message.Bcc [i].Address + '>');
 671                                 if (IsError (status))
 672                                         sfre.Add (new SmtpFailedRecipientException (status.StatusCode, message.Bcc [i].Address));
 673                         }
 674
 675                         if (sfre.Count >0)
 676                                 throw new SmtpFailedRecipientsException ("failed recipients", sfre.ToArray ());
 677
 678                         // DATA
 679                         status = SendCommand ("DATA");
 680                         if (IsError (status))
 681                                 throw new SmtpException (status.StatusCode, status.Description);
 682
 683                         // Send message headers
 684                         string dt = DateTime.Now.ToString ("ddd, dd MMM yyyy HH':'mm':'ss zzz", DateTimeFormatInfo.InvariantInfo);
 685                         // remove ':' from time zone offset (e.g. from "+01:00")
 686                         dt = dt.Remove (dt.Length - 3, 1);
 687                         SendHeader (HeaderName.Date, dt);
 688
 689                         MailAddress from = message.From;
 690                         if (from == null)
 691                                 from = defaultFrom;
 692
 693                         SendHeader (HeaderName.From, EncodeAddress (from));
 694                         SendHeader (HeaderName.To, EncodeAddresses (message.To));
 695                         if (message.CC.Count > 0)
 696                                 SendHeader (HeaderName.Cc, EncodeAddresses (message.CC));
 697                         SendHeader (HeaderName.Subject, EncodeSubjectRFC2047 (message));
 698
 699                         string v = "normal";
 700
 701                         switch (message.Priority){
 702                         case MailPriority.Normal:
 703                                 v = "normal";
 704                                 break;
 705
 706                         case MailPriority.Low:
 707                                 v = "non-urgent";
 708                                 break;
 709
 710                         case MailPriority.High:
 711                                 v = "urgent";
 712                                 break;
 713                         }
 714                         SendHeader ("Priority", v);
 715                         if (message.Sender != null)
 716                                 SendHeader ("Sender", EncodeAddress (message.Sender));
 717                         if (message.ReplyToList.Count > 0)
 718                                 SendHeader ("Reply-To", EncodeAddresses (message.ReplyToList));
 719
 720                         foreach (string s in message.Headers.AllKeys)
 721                                 SendHeader (s, MailMessage.EncodeSubjectRFC2047 (message.Headers [s], message.HeadersEncoding));
 722
 723                         AddPriorityHeader (message);
 724
 725                         boundaryIndex = 0;
 726                         if (message.Attachments.Count > 0)
 727                                 SendWithAttachments (message);
 728                         else
 729                                 SendWithoutAttachments (message, null, false);
 730
 731                         SendDot ();
 732
 733                         status = Read ();
 734                         if (IsError (status))
 735                                 throw new SmtpException (status.StatusCode, status.Description);
 736
 737                         try {
 738                                 status = SendCommand ("QUIT");
 739                         } catch (System.IO.IOException) {
 740                                 // We excuse server for the rude connection closing as a response to QUIT
 741                         }
 742                 }
 743
 744                 public void Send (string from, string to, string subject, string body)
 745                 {
 746                         Send (new MailMessage (from, to, subject, body));
 747                 }
 748
 749                 public Task SendMailAsync (MailMessage message)
 750                 {
 751                         var tcs = new TaskCompletionSource<object> ();
 752                         SendCompletedEventHandler handler = null;
 753                         handler = (s, e) => SendMailAsyncCompletedHandler (tcs, e, handler, this);
 754                         SendCompleted += handler;
 755                         SendAsync (message, tcs);
 756                         return tcs.Task;
 757                 }
 758
 759                 public Task SendMailAsync (string from, string recipients, string subject, string body)
 760                 {
 761                         return SendMailAsync (new MailMessage (from, recipients, subject, body));
 762                 }
 763
 764                 static void SendMailAsyncCompletedHandler (TaskCompletionSource<object> source, AsyncCompletedEventArgs e, SendCompletedEventHandler handler, SmtpClient client)
 765                 {
 766                         if (source != e.UserState)
 767                                 return;
 768
 769                         client.SendCompleted -= handler;
 770
 771                         if (e.Error != null) {
 772                                 source.SetException (e.Error);
 773                                 return;
 774                         }
 775
 776                         if (e.Cancelled) {
 777                                 source.SetCanceled ();
 778                                 return;
 779                         }
 780
 781                         source.SetResult (null);
 782                 }
 783
 784                 private void SendDot()
 785                 {
 786                         writer.Write(".\r\n");
 787                         writer.Flush();
 788                 }
 789
 790                 private void SendData (string data)
 791                 {
 792                         if (String.IsNullOrEmpty (data)) {
 793                                 writer.Write("\r\n");
 794                                 writer.Flush();
 795                                 return;
 796                         }
 797
 798                         StringReader sr = new StringReader (data);
 799                         string line;
 800                         bool escapeDots = deliveryMethod == SmtpDeliveryMethod.Network;
 801                         while ((line = sr.ReadLine ()) != null) {
 802                                 CheckCancellation ();
 803
 804                                 if (escapeDots) {
 805                                         if (line.Length > 0 && line[0] == '.') {
 806                                                 line = "." + line;
 807                                         }
 808                                 }
 809                                 writer.Write (line);
 810                                 writer.Write ("\r\n");
 811                         }
 812                         writer.Flush ();
 813                 }
 814
 815                 public void SendAsync (MailMessage message, object userToken)
 816                 {
 817                         if (worker != null)
 818                                 throw new InvalidOperationException ("Another SendAsync operation is in progress");
 819
 820                         worker = new BackgroundWorker ();
 821                         worker.DoWork += delegate (object o, DoWorkEventArgs ea) {
 822                                 try {
 823                                         user_async_state = ea.Argument;
 824                                         Send (message);
 825                                 } catch (Exception ex) {
 826                                         ea.Result = ex;
 827                                         throw ex;
 828                                 }
 829                         };
 830                         worker.WorkerSupportsCancellation = true;
 831                         worker.RunWorkerCompleted += delegate (object o, RunWorkerCompletedEventArgs ea) {
 832                                 // Note that RunWorkerCompletedEventArgs.UserState cannot be used (LAMESPEC)
 833                                 OnSendCompleted (new AsyncCompletedEventArgs (ea.Error, ea.Cancelled, user_async_state));
 834                         };
 835                         worker.RunWorkerAsync (userToken);
 836                 }
 837
 838                 public void SendAsync (string from, string to, string subject, string body, object userToken)
 839                 {
 840                         SendAsync (new MailMessage (from, to, subject, body), userToken);
 841                 }
 842
 843                 public void SendAsyncCancel ()
 844                 {
 845                         if (worker == null)
 846                                 throw new InvalidOperationException ("SendAsync operation is not in progress");
 847                         worker.CancelAsync ();
 848                 }
 849
 850                 private void AddPriorityHeader (MailMessage message) {
 851                         switch (message.Priority) {
 852                         case MailPriority.High:
 853                                 SendHeader (HeaderName.Priority, "Urgent");
 854                                 SendHeader (HeaderName.Importance, "high");
 855                                 SendHeader (HeaderName.XPriority, "1");
 856                                 break;
 857                         case MailPriority.Low:
 858                                 SendHeader (HeaderName.Priority, "Non-Urgent");
 859                                 SendHeader (HeaderName.Importance, "low");
 860                                 SendHeader (HeaderName.XPriority, "5");
 861                                 break;
 862                         }
 863                 }
 864
 865                 private void SendSimpleBody (MailMessage message) {
 866                         SendHeader (HeaderName.ContentType, message.BodyContentType.ToString ());
 867                         if (message.ContentTransferEncoding != TransferEncoding.SevenBit)
 868                                 SendHeader (HeaderName.ContentTransferEncoding, GetTransferEncodingName (message.ContentTransferEncoding));
 869                         SendData (string.Empty);
 870
 871                         SendData (EncodeBody (message));
 872                 }
 873
 874                 private void SendBodylessSingleAlternate (AlternateView av) {
 875                         SendHeader (HeaderName.ContentType, av.ContentType.ToString ());
 876                         if (av.TransferEncoding != TransferEncoding.SevenBit)
 877                                 SendHeader (HeaderName.ContentTransferEncoding, GetTransferEncodingName (av.TransferEncoding));
 878                         SendData (string.Empty);
 879
 880                         SendData (EncodeBody (av));
 881                 }
 882
 883                 private void SendWithoutAttachments (MailMessage message, string boundary, bool attachmentExists)
 884                 {
 885                         if (message.Body == null && message.AlternateViews.Count == 1)
 886                                 SendBodylessSingleAlternate (message.AlternateViews [0]);
 887                         else if (message.AlternateViews.Count > 0)
 888                                 SendBodyWithAlternateViews (message, boundary, attachmentExists);
 889                         else
 890                                 SendSimpleBody (message);
 891                 }
 892
 893
 894                 private void SendWithAttachments (MailMessage message) {
 895                         string boundary = GenerateBoundary ();
 896
 897                         // first "multipart/mixed"
 898                         ContentType messageContentType = new ContentType ();
 899                         messageContentType.Boundary = boundary;
 900                         messageContentType.MediaType = "multipart/mixed";
 901                         messageContentType.CharSet = null;
 902
 903                         SendHeader (HeaderName.ContentType, messageContentType.ToString ());
 904                         SendData (String.Empty);
 905
 906                         // body section
 907                         Attachment body = null;
 908
 909                         if (message.AlternateViews.Count > 0)
 910                                 SendWithoutAttachments (message, boundary, true);
 911                         else {
 912                                 body = Attachment.CreateAttachmentFromString (message.Body, null, message.BodyEncoding, message.IsBodyHtml ? "text/html" : "text/plain");
 913                                 message.Attachments.Insert (0, body);
 914                         }
 915
 916                         try {
 917                                 SendAttachments (message, body, boundary);
 918                         } finally {
 919                                 if (body != null)
 920                                         message.Attachments.Remove (body);
 921                         }
 922
 923                         EndSection (boundary);
 924                 }
 925
 926                 private void SendBodyWithAlternateViews (MailMessage message, string boundary, bool attachmentExists)
 927                 {
 928                         AlternateViewCollection alternateViews = message.AlternateViews;
 929
 930                         string inner_boundary = GenerateBoundary ();
 931
 932                         ContentType messageContentType = new ContentType ();
 933                         messageContentType.Boundary = inner_boundary;
 934                         messageContentType.MediaType = "multipart/alternative";
 935
 936                         if (!attachmentExists) {
 937                                 SendHeader (HeaderName.ContentType, messageContentType.ToString ());
 938                                 SendData (String.Empty);
 939                         }
 940
 941                         // body section
 942                         AlternateView body = null;
 943                         if (message.Body != null) {
 944                                 body = AlternateView.CreateAlternateViewFromString (message.Body, message.BodyEncoding, message.IsBodyHtml ? "text/html" : "text/plain");
 945                                 alternateViews.Insert (0, body);
 946                                 StartSection (boundary, messageContentType);
 947                         }
 948
 949 try {
 950                         // alternate view sections
 951                         foreach (AlternateView av in alternateViews) {
 952
 953                                 string alt_boundary = null;
 954                                 ContentType contentType;
 955                                 if (av.LinkedResources.Count > 0) {
 956                                         alt_boundary = GenerateBoundary ();
 957                                         contentType = new ContentType ("multipart/related");
 958                                         contentType.Boundary = alt_boundary;
 959
 960                                         contentType.Parameters ["type"] = av.ContentType.ToString ();
 961                                         StartSection (inner_boundary, contentType);
 962                                         StartSection (alt_boundary, av.ContentType, av);
 963                                 } else {
 964                                         contentType = new ContentType (av.ContentType.ToString ());
 965                                         StartSection (inner_boundary, contentType, av);
 966                                 }
 967
 968                                 switch (av.TransferEncoding) {
 969                                 case TransferEncoding.Base64:
 970                                         byte [] content = new byte [av.ContentStream.Length];
 971                                         av.ContentStream.Read (content, 0, content.Length);
 972                                             SendData (Convert.ToBase64String (content, Base64FormattingOptions.InsertLineBreaks));
 973                                         break;
 974                                 case TransferEncoding.QuotedPrintable:
 975                                         byte [] bytes = new byte [av.ContentStream.Length];
 976                                         av.ContentStream.Read (bytes, 0, bytes.Length);
 977                                         SendData (ToQuotedPrintable (bytes));
 978                                         break;
 979                                 case TransferEncoding.SevenBit:
 980                                 case TransferEncoding.Unknown:
 981                                         content = new byte [av.ContentStream.Length];
 982                                         av.ContentStream.Read (content, 0, content.Length);
 983                                         SendData (Encoding.ASCII.GetString (content));
 984                                         break;
 985                                 }
 986
 987                                 if (av.LinkedResources.Count > 0) {
 988                                         SendLinkedResources (message, av.LinkedResources, alt_boundary);
 989                                         EndSection (alt_boundary);
 990                                 }
 991
 992                                 if (!attachmentExists)
 993                                         SendData (string.Empty);
 994                         }
 995
 996 } finally {
 997                         if (body != null)
 998                                 alternateViews.Remove (body);
 999 }
1000                         EndSection (inner_boundary);
1001                 }
1002
1003                 private void SendLinkedResources (MailMessage message, LinkedResourceCollection resources, string boundary)
1004                 {
1005                         foreach (LinkedResource lr in resources) {
1006                                 StartSection (boundary, lr.ContentType, lr);
1007
1008                                 switch (lr.TransferEncoding) {
1009                                 case TransferEncoding.Base64:
1010                                         byte [] content = new byte [lr.ContentStream.Length];
1011                                         lr.ContentStream.Read (content, 0, content.Length);
1012                                             SendData (Convert.ToBase64String (content, Base64FormattingOptions.InsertLineBreaks));
1013                                         break;
1014                                 case TransferEncoding.QuotedPrintable:
1015                                         byte [] bytes = new byte [lr.ContentStream.Length];
1016                                         lr.ContentStream.Read (bytes, 0, bytes.Length);
1017                                         SendData (ToQuotedPrintable (bytes));
1018                                         break;
1019                                 case TransferEncoding.SevenBit:
1020                                 case TransferEncoding.Unknown:
1021                                         content = new byte [lr.ContentStream.Length];
1022                                         lr.ContentStream.Read (content, 0, content.Length);
1023                                         SendData (Encoding.ASCII.GetString (content));
1024                                         break;
1025                                 }
1026                         }
1027                 }
1028
1029                 private void SendAttachments (MailMessage message, Attachment body, string boundary) {
1030                         foreach (Attachment att in message.Attachments) {
1031                                 ContentType contentType = new ContentType (att.ContentType.ToString ());
1032                                 if (att.Name != null) {
1033                                         contentType.Name = att.Name;
1034                                         if (att.NameEncoding != null)
1035                                                 contentType.CharSet = att.NameEncoding.HeaderName;
1036                                         att.ContentDisposition.FileName = att.Name;
1037                                 }
1038                                 StartSection (boundary, contentType, att, att != body);
1039
1040                                 byte [] content = new byte [att.ContentStream.Length];
1041                                 att.ContentStream.Read (content, 0, content.Length);
1042                                 switch (att.TransferEncoding) {
1043                                 case TransferEncoding.Base64:
1044                                         SendData (Convert.ToBase64String (content, Base64FormattingOptions.InsertLineBreaks));
1045                                         break;
1046                                 case TransferEncoding.QuotedPrintable:
1047                                         SendData (ToQuotedPrintable (content));
1048                                         break;
1049                                 case TransferEncoding.SevenBit:
1050                                 case TransferEncoding.Unknown:
1051                                         SendData (Encoding.ASCII.GetString (content));
1052                                         break;
1053                                 }
1054
1055                                 SendData (string.Empty);
1056                         }
1057                 }
1058
1059                 private SmtpResponse SendCommand (string command)
1060                 {
1061                         writer.Write (command);
1062                         // Certain SMTP servers will reject mail sent with unix line-endings; see http://cr.yp.to/docs/smtplf.html
1063                         writer.Write ("\r\n");
1064                         writer.Flush ();
1065                         return Read ();
1066                 }
1067
1068                 private void SendHeader (string name, string value)
1069                 {
1070                         SendData (String.Format ("{0}: {1}", name, value));
1071                 }
1072
1073                 private void StartSection (string section, ContentType sectionContentType)
1074                 {
1075                         SendData (String.Format ("--{0}", section));
1076                         SendHeader ("content-type", sectionContentType.ToString ());
1077                         SendData (string.Empty);
1078                 }
1079
1080                 private void StartSection (string section, ContentType sectionContentType, AttachmentBase att)
1081                 {
1082                         SendData (String.Format ("--{0}", section));
1083                         SendHeader ("content-type", sectionContentType.ToString ());
1084                         SendHeader ("content-transfer-encoding", GetTransferEncodingName (att.TransferEncoding));
1085                         if (!string.IsNullOrEmpty (att.ContentId))
1086                                 SendHeader("content-ID", "<" + att.ContentId + ">");
1087                         SendData (string.Empty);
1088                 }
1089
1090                 private void StartSection (string section, ContentType sectionContentType, Attachment att, bool sendDisposition) {
1091                         SendData (String.Format ("--{0}", section));
1092                         if (!string.IsNullOrEmpty (att.ContentId))
1093                                 SendHeader("content-ID", "<" + att.ContentId + ">");
1094                         SendHeader ("content-type", sectionContentType.ToString ());
1095                         SendHeader ("content-transfer-encoding", GetTransferEncodingName (att.TransferEncoding));
1096                         if (sendDisposition)
1097                                 SendHeader ("content-disposition", att.ContentDisposition.ToString ());
1098                         SendData (string.Empty);
1099                 }
1100
1101                 // use proper encoding to escape input
1102                 private string ToQuotedPrintable (string input, Encoding enc)
1103                 {
1104                         byte [] bytes = enc.GetBytes (input);
1105                         return ToQuotedPrintable (bytes);
1106                 }
1107
1108                 private string ToQuotedPrintable (byte [] bytes)
1109                 {
1110                         StringWriter writer = new StringWriter ();
1111                         int charsInLine = 0;
1112                         int curLen;
1113                         StringBuilder sb = new StringBuilder("=", 3);
1114                         byte equalSign = (byte)'=';
1115                         char c = (char)0;
1116
1117                         foreach (byte i in bytes) {
1118                                 if (i > 127 || i == equalSign) {
1119                                         sb.Length = 1;
1120                                         sb.Append(Convert.ToString (i, 16).ToUpperInvariant ());
1121                                         curLen = 3;
1122                                 } else {
1123                                         c = Convert.ToChar (i);
1124                                         if (c == '\r' || c == '\n') {
1125                                                 writer.Write (c);
1126                                                 charsInLine = 0;
1127                                                 continue;
1128                                         }
1129                                         curLen = 1;
1130                                 }
1131
1132                                 charsInLine += curLen;
1133                                 if (charsInLine > 75) {
1134                                         writer.Write ("=\r\n");
1135                                         charsInLine = curLen;
1136                                 }
1137                                 if (curLen == 1)
1138                                         writer.Write (c);
1139                                 else
1140                                         writer.Write (sb.ToString ());
1141                         }
1142
1143                         return writer.ToString ();
1144                 }
1145                 private static string GetTransferEncodingName (TransferEncoding encoding)
1146                 {
1147                         switch (encoding) {
1148                         case TransferEncoding.QuotedPrintable:
1149                                 return "quoted-printable";
1150                         case TransferEncoding.SevenBit:
1151                                 return "7bit";
1152                         case TransferEncoding.Base64:
1153                                 return "base64";
1154                         }
1155                         return "unknown";
1156                 }
1157
1158                 private void InitiateSecureConnection () {
1159                         SmtpResponse response = SendCommand ("STARTTLS");
1160
1161                         if (IsError (response)) {
1162                                 throw new SmtpException (SmtpStatusCode.GeneralFailure, "Server does not support secure connections.");
1163                         }
1164
1165 #if SECURITY_DEP
1166                         var tlsProvider = MonoTlsProviderFactory.GetProviderInternal ();
1167                         var settings = MSI.MonoTlsSettings.CopyDefaultSettings ();
1168                         settings.UseServicePointManagerCallback = true;
1169                         var sslStream = tlsProvider.CreateSslStream (stream, false, settings);
1170                         CheckCancellation ();
1171                         sslStream.AuthenticateAsClient (Host, this.ClientCertificates, SslProtocols.Default, false);
1172                         stream = sslStream.AuthenticatedStream;
1173
1174 #else
1175                         throw new SystemException ("You are using an incomplete System.dll build");
1176 #endif
1177                 }
1178
1179                 void Authenticate ()
1180                 {
1181                         string user = null, pass = null;
1182
1183                         if (UseDefaultCredentials) {
1184                                 user = CredentialCache.DefaultCredentials.GetCredential (new System.Uri ("smtp://" + host), "basic").UserName;
1185                                 pass =  CredentialCache.DefaultCredentials.GetCredential (new System.Uri ("smtp://" + host), "basic").Password;
1186                         } else if (Credentials != null) {
1187                                 user = Credentials.GetCredential (host, port, "smtp").UserName;
1188                                 pass = Credentials.GetCredential (host, port, "smtp").Password;
1189                         } else {
1190                                 return;
1191                         }
1192
1193                         Authenticate (user, pass);
1194                 }
1195
1196                 void CheckStatus (SmtpResponse status, int i)
1197                 {
1198                         if (((int) status.StatusCode) != i)
1199                                 throw new SmtpException (status.StatusCode, status.Description);
1200                 }
1201
1202                 void ThrowIfError (SmtpResponse status)
1203                 {
1204                         if (IsError (status))
1205                                 throw new SmtpException (status.StatusCode, status.Description);
1206                 }
1207
1208                 void Authenticate (string user, string password)
1209                 {
1210                         if (authMechs == AuthMechs.None)
1211                                 return;
1212
1213                         SmtpResponse status;
1214                         /*
1215                         if ((authMechs & AuthMechs.DigestMD5) != 0) {
1216                                 status = SendCommand ("AUTH DIGEST-MD5");
1217                                 CheckStatus (status, 334);
1218                                 string challenge = Encoding.ASCII.GetString (Convert.FromBase64String (status.Description.Substring (4)));
1219                                 Console.WriteLine ("CHALLENGE: {0}", challenge);
1220                                 DigestSession session = new DigestSession ();
1221                                 session.Parse (false, challenge);
1222                                 string response = session.Authenticate (this, user, password);
1223                                 status = SendCommand (Convert.ToBase64String (Encoding.UTF8.GetBytes (response)));
1224                                 CheckStatus (status, 235);
1225                         } else */
1226                         if ((authMechs & AuthMechs.Login) != 0) {
1227                                 status = SendCommand ("AUTH LOGIN");
1228                                 CheckStatus (status, 334);
1229                                 status = SendCommand (Convert.ToBase64String (Encoding.UTF8.GetBytes (user)));
1230                                 CheckStatus (status, 334);
1231                                 status = SendCommand (Convert.ToBase64String (Encoding.UTF8.GetBytes (password)));
1232                                 CheckStatus (status, 235);
1233                         } else if ((authMechs & AuthMechs.Plain) != 0) {
1234                                 string s = String.Format ("\0{0}\0{1}", user, password);
1235                                 s = Convert.ToBase64String (Encoding.UTF8.GetBytes (s));
1236                                 status = SendCommand ("AUTH PLAIN " + s);
1237                                 CheckStatus (status, 235);
1238                         } else {
1239                                 throw new SmtpException ("AUTH types PLAIN, LOGIN not supported by the server");
1240                         }
1241                 }
1242
1243                 #endregion // Methods
1244
1245                 // The HeaderName struct is used to store constant string values representing mail headers.
1246                 private struct HeaderName {
1247                         public const string ContentTransferEncoding = "Content-Transfer-Encoding";
1248                         public const string ContentType = "Content-Type";
1249                         public const string Bcc = "Bcc";
1250                         public const string Cc = "Cc";
1251                         public const string From = "From";
1252                         public const string Subject = "Subject";
1253                         public const string To = "To";
1254                         public const string MimeVersion = "MIME-Version";
1255                         public const string MessageId = "Message-ID";
1256                         public const string Priority = "Priority";
1257                         public const string Importance = "Importance";
1258                         public const string XPriority = "X-Priority";
1259                         public const string Date = "Date";
1260                 }
1261
1262                 // This object encapsulates the status code and description of an SMTP response.
1263                 private struct SmtpResponse {
1264                         public SmtpStatusCode StatusCode;
1265                         public string Description;
1266
1267                         public static SmtpResponse Parse (string line) {
1268                                 SmtpResponse response = new SmtpResponse ();
1269
1270                                 if (line.Length < 4)
1271                                         throw new SmtpException ("Response is to short " +
1272                                                                  line.Length + ".");
1273
1274                                 if ((line [3] != ' ') && (line [3] != '-'))
1275                                         throw new SmtpException ("Response format is wrong.(" +
1276                                                                  line + ")");
1277
1278                                 // parse the response code
1279                                 response.StatusCode = (SmtpStatusCode) Int32.Parse (line.Substring (0, 3));
1280
1281                                 // set the raw response
1282                                 response.Description = line;
1283
1284                                 return response;
1285                         }
1286                 }
1287         }
1288
1289         class CCredentialsByHost : ICredentialsByHost
1290         {
1291                 public CCredentialsByHost (string userName, string password) {
1292                         this.userName = userName;
1293                         this.password = password;
1294                 }
1295
1296                 public NetworkCredential GetCredential (string host, int port, string authenticationType) {
1297                         return new NetworkCredential (userName, password);
1298                 }
1299
1300                 private string userName;
1301                 private string password;
1302         }
1303 }
1304