class/deliver/Deliver_SMTP.class.php

   1 <?php
   2
   3 /**
   4  * Deliver_SMTP.class.php
   5  *
   6  * SMTP delivery backend for the Deliver class.
   7  *
   8  * @copyright 1999-2011 The SquirrelMail Project Team
   9  * @license http://opensource.org/licenses/gpl-license.php GNU Public License
  10  * @version $Id$
  11  * @package squirrelmail
  12  */
  13
  14 /** @ignore */
  15 if (!defined('SM_PATH')) define('SM_PATH','../../');
  16
  17 /** This of course depends upon Deliver */
  18 include_once(SM_PATH . 'class/deliver/Deliver.class.php');
  19
  20 /**
  21  * Deliver messages using SMTP
  22  * @package squirrelmail
  23  */
  24 class Deliver_SMTP extends Deliver {
  25     /**
  26      * Array keys are uppercased ehlo keywords
  27      * array key values are ehlo params. If ehlo-param contains space, it is splitted into array.
  28      * @var array ehlo
  29      * @since 1.5.1
  30      */
  31     var $ehlo = array();
  32     /**
  33      * @var string domain
  34      * @since 1.5.1
  35      */
  36     var $domain = '';
  37     /**
  38      * SMTP STARTTLS rfc: "Both the client and the server MUST know if there
  39      * is a TLS session active."
  40      * Variable should be set to true, when encryption is turned on.
  41      * @var boolean
  42      * @since 1.5.1
  43      */
  44     var $tls_enabled = false;
  45     /**
  46      * Private var
  47      * var stream $stream
  48      * @todo don't pass stream resource in class method arguments.
  49      */
  50     //var $stream = false;
  51     /** @var string delivery error message */
  52     var $dlv_msg = '';
  53     /** @var integer delivery error number from server */
  54     var $dlv_ret_nr = '';
  55     /** @var string delivery error message from server */
  56     var $dlv_server_msg = '';
  57
  58     function preWriteToStream(&$s) {
  59         if ($s) {
  60             if ($s{0} == '.')   $s = '.' . $s;
  61             $s = str_replace("\n.","\n..",$s);
  62         }
  63     }
  64
  65     function initStream($message, $domain, $length=0, $host='', $port='', $user='', $pass='', $authpop=false, $pop_host='') {
  66         global $use_smtp_tls,$smtp_auth_mech;
  67
  68         if ($authpop) {
  69             $this->authPop($pop_host, '', $user, $pass);
  70         }
  71
  72         $rfc822_header = $message->rfc822_header;
  73
  74         $from = $rfc822_header->from[0];
  75         $to =   $rfc822_header->to;
  76         $cc =   $rfc822_header->cc;
  77         $bcc =  $rfc822_header->bcc;
  78         $content_type  = $rfc822_header->content_type;
  79
  80         // MAIL FROM: <from address> MUST be empty in cae of MDN (RFC2298)
  81         if ($content_type->type0 == 'multipart' &&
  82             $content_type->type1 == 'report' &&
  83             isset($content_type->properties['report-type']) &&
  84             $content_type->properties['report-type']=='disposition-notification') {
  85             // reinitialize the from object because otherwise the from header somehow
  86             // is affected. This $from var is used for smtp command MAIL FROM which
  87             // is not the same as what we put in the rfc822 header.
  88             $from = new AddressStructure();
  89             $from->host = '';
  90             $from->mailbox = '';
  91         }
  92
  93         if ($use_smtp_tls == 1) {
  94             if ((check_php_version(4,3)) && (extension_loaded('openssl'))) {
  95                 $stream = @fsockopen('tls://' . $host, $port, $errorNumber, $errorString);
  96                 $this->tls_enabled = true;
  97             } else {
  98                 /**
  99                  * don't connect to server when user asks for smtps and
 100                  * PHP does not support it.
 101                  */
 102                 $errorNumber = '';
 103                 $errorString = _("Secure SMTP (TLS) is enabled in SquirrelMail configuration, but used PHP version does not support it.");
 104             }
 105         } else {
 106             $stream = @fsockopen($host, $port, $errorNumber, $errorString);
 107         }
 108
 109         if (!$stream) {
 110             // reset tls state var to default value, if connection fails
 111             $this->tls_enabled = false;
 112             // set error messages
 113             $this->dlv_msg = $errorString;
 114             $this->dlv_ret_nr = $errorNumber;
 115             $this->dlv_server_msg = _("Can't open SMTP stream.");
 116             return(0);
 117         }
 118         // get server greeting
 119         $tmp = fgets($stream, 1024);
 120         if ($this->errorCheck($tmp, $stream)) {
 121             return(0);
 122         }
 123
 124         /*
 125          * If $_SERVER['HTTP_HOST'] is set, use that in our HELO to the SMTP
 126          * server.  This should fix the DNS issues some people have had
 127          */
 128         if (sqgetGlobalVar('HTTP_HOST', $HTTP_HOST, SQ_SERVER)) { // HTTP_HOST is set
 129             // optionally trim off port number
 130             if($p = strrpos($HTTP_HOST, ':')) {
 131                 $HTTP_HOST = substr($HTTP_HOST, 0, $p);
 132             }
 133             $helohost = $HTTP_HOST;
 134         } else { // For some reason, HTTP_HOST is not set - revert to old behavior
 135             $helohost = $domain;
 136         }
 137
 138         // if the host is an IPv4 address, enclose it in brackets
 139         //
 140         if (preg_match('/^\d+\.\d+\.\d+\.\d+$/', $helohost))
 141             $helohost = '[' . $helohost . ']';
 142
 143         /* Lets introduce ourselves */
 144         fputs($stream, "EHLO $helohost\r\n");
 145         // Read ehlo response
 146         $tmp = $this->parse_ehlo_response($stream);
 147         if ($this->errorCheck($tmp,$stream)) {
 148             // fall back to HELO if EHLO is not supported (error 5xx)
 149             if ($this->dlv_ret_nr{0} == '5') {
 150                 fputs($stream, "HELO $helohost\r\n");
 151                 $tmp = fgets($stream,1024);
 152                 if ($this->errorCheck($tmp,$stream)) {
 153                     return(0);
 154                 }
 155             } else {
 156                 return(0);
 157             }
 158         }
 159
 160         /**
 161          * Implementing SMTP STARTTLS (rfc2487) in php 5.1.0+
 162          * http://www.php.net/stream-socket-enable-crypto
 163          */
 164         if ($use_smtp_tls === 2) {
 165             if (function_exists('stream_socket_enable_crypto')) {
 166                 // don't try starting tls, when client thinks that it is already active
 167                 if ($this->tls_enabled) {
 168                     $this->dlv_msg = _("TLS session is already activated.");
 169                     return 0;
 170                 } elseif (!array_key_exists('STARTTLS',$this->ehlo)) {
 171                     // check for starttls in ehlo response
 172                     $this->dlv_msg = _("SMTP STARTTLS is enabled in SquirrelMail configuration, but used SMTP server does not support it");
 173                     return 0;
 174                 }
 175
 176                 // issue starttls command
 177                 fputs($stream, "STARTTLS\r\n");
 178                 // get response
 179                 $tmp = fgets($stream,1024);
 180                 if ($this->errorCheck($tmp,$stream)) {
 181                     return 0;
 182                 }
 183
 184                 // start crypto on connection. suppress function errors.
 185                 if (@stream_socket_enable_crypto($stream,true,STREAM_CRYPTO_METHOD_TLS_CLIENT)) {
 186                     // starttls was successful (rfc2487 5.2 Result of the STARTTLS Command)
 187                     // get new EHLO response
 188                     fputs($stream, "EHLO $helohost\r\n");
 189                     // Read ehlo response
 190                     $tmp = $this->parse_ehlo_response($stream);
 191                     if ($this->errorCheck($tmp,$stream)) {
 192                         // don't revert to helo here. server must support ESMTP
 193                         return 0;
 194                     }
 195                     // set information about started tls
 196                     $this->tls_enabled = true;
 197                 } else {
 198                     /**
 199                      * stream_socket_enable_crypto() call failed.
 200                      */
 201                     $this->dlv_msg = _("Unable to start TLS.");
 202                     return 0;
 203                     // Bug: can't get error message. See comments in sqimap_create_stream().
 204                 }
 205             } else {
 206                 // php install does not support stream_socket_enable_crypto() function
 207                 $this->dlv_msg = _("SMTP STARTTLS is enabled in SquirrelMail configuration, but used PHP version does not support functions that allow to enable encryption on open socket.");
 208                 return 0;
 209             }
 210         }
 211
 212         // FIXME: check ehlo response before using authentication
 213
 214         // Try authentication by a plugin
 215         //
 216         // NOTE: there is another hook in functions/auth.php called "smtp_auth"
 217         // that allows a plugin to specify a different set of login credentials
 218         // (so is slightly mis-named, but is too old to change), so be careful
 219         // that you do not confuse your hook names.
 220         //
 221         $smtp_auth_args = array(
 222             'auth_mech' => $smtp_auth_mech,
 223             'user' => $user,
 224             'pass' => $pass,
 225             'host' => $host,
 226             'port' => $port,
 227             'stream' => $stream,
 228         );
 229         if (boolean_hook_function('smtp_authenticate', $smtp_auth_args, 1)) {
 230             // authentication succeeded
 231         } else if (( $smtp_auth_mech == 'cram-md5') or ( $smtp_auth_mech == 'digest-md5' )) {
 232             // Doing some form of non-plain auth
 233             if ($smtp_auth_mech == 'cram-md5') {
 234                 fputs($stream, "AUTH CRAM-MD5\r\n");
 235             } elseif ($smtp_auth_mech == 'digest-md5') {
 236                 fputs($stream, "AUTH DIGEST-MD5\r\n");
 237             }
 238
 239             $tmp = fgets($stream,1024);
 240
 241             if ($this->errorCheck($tmp,$stream)) {
 242                 return(0);
 243             }
 244
 245             // At this point, $tmp should hold "334 <challenge string>"
 246             $chall = substr($tmp,4);
 247             // Depending on mechanism, generate response string
 248             if ($smtp_auth_mech == 'cram-md5') {
 249                 $response = cram_md5_response($user,$pass,$chall);
 250             } elseif ($smtp_auth_mech == 'digest-md5') {
 251                 $response = digest_md5_response($user,$pass,$chall,'smtp',$host);
 252             }
 253             fputs($stream, $response);
 254
 255             // Let's see what the server had to say about that
 256             $tmp = fgets($stream,1024);
 257             if ($this->errorCheck($tmp,$stream)) {
 258                 return(0);
 259             }
 260
 261             // CRAM-MD5 is done at this point.  If DIGEST-MD5, there's a bit more to go
 262             if ($smtp_auth_mech == 'digest-md5') {
 263                 // $tmp contains rspauth, but I don't store that yet. (No need yet)
 264                 fputs($stream,"\r\n");
 265                 $tmp = fgets($stream,1024);
 266
 267                 if ($this->errorCheck($tmp,$stream)) {
 268                 return(0);
 269                 }
 270             }
 271         // CRAM-MD5 and DIGEST-MD5 code ends here
 272         } elseif ($smtp_auth_mech == 'none') {
 273         // No auth at all, just send helo and then send the mail
 274         // We already said hi earlier, nothing more is needed.
 275         } elseif ($smtp_auth_mech == 'login') {
 276             // The LOGIN method
 277             fputs($stream, "AUTH LOGIN\r\n");
 278             $tmp = fgets($stream, 1024);
 279
 280             if ($this->errorCheck($tmp, $stream)) {
 281                 return(0);
 282             }
 283             fputs($stream, base64_encode ($user) . "\r\n");
 284             $tmp = fgets($stream, 1024);
 285             if ($this->errorCheck($tmp, $stream)) {
 286                 return(0);
 287             }
 288
 289             fputs($stream, base64_encode($pass) . "\r\n");
 290             $tmp = fgets($stream, 1024);
 291             if ($this->errorCheck($tmp, $stream)) {
 292                 return(0);
 293             }
 294         } elseif ($smtp_auth_mech == "plain") {
 295             /* SASL Plain */
 296             $auth = base64_encode("$user\0$user\0$pass");
 297
 298             $query = "AUTH PLAIN\r\n";
 299             fputs($stream, $query);
 300             $read=fgets($stream, 1024);
 301
 302             if (substr($read,0,3) == '334') { // OK so far..
 303                 fputs($stream, "$auth\r\n");
 304                 $read = fgets($stream, 1024);
 305             }
 306
 307             $results=explode(" ",$read,3);
 308             $response=$results[1];
 309             $message=$results[2];
 310         } else {
 311             /* Right here, they've reached an unsupported auth mechanism.
 312             This is the ugliest hack I've ever done, but it'll do till I can fix
 313             things up better tomorrow.  So tired... */
 314             if ($this->errorCheck("535 Unable to use this auth type",$stream)) {
 315                 return(0);
 316             }
 317         }
 318
 319         /* Ok, who is sending the message? */
 320         $fromaddress = (strlen($from->mailbox) && $from->host) ?
 321             $from->mailbox.'@'.$from->host : '';
 322         fputs($stream, 'MAIL FROM:<'.$fromaddress.">\r\n");
 323         $tmp = fgets($stream, 1024);
 324         if ($this->errorCheck($tmp, $stream)) {
 325             return(0);
 326         }
 327
 328         /* send who the recipients are */
 329         for ($i = 0, $cnt = count($to); $i < $cnt; $i++) {
 330             if (!$to[$i]->host) $to[$i]->host = $domain;
 331             if (strlen($to[$i]->mailbox)) {
 332                 fputs($stream, 'RCPT TO:<'.$to[$i]->mailbox.'@'.$to[$i]->host.">\r\n");
 333                 $tmp = fgets($stream, 1024);
 334                 if ($this->errorCheck($tmp, $stream)) {
 335                     return(0);
 336                 }
 337             }
 338         }
 339
 340         for ($i = 0, $cnt = count($cc); $i < $cnt; $i++) {
 341             if (!$cc[$i]->host) $cc[$i]->host = $domain;
 342             if (strlen($cc[$i]->mailbox)) {
 343                 fputs($stream, 'RCPT TO:<'.$cc[$i]->mailbox.'@'.$cc[$i]->host.">\r\n");
 344                 $tmp = fgets($stream, 1024);
 345                 if ($this->errorCheck($tmp, $stream)) {
 346                     return(0);
 347                 }
 348             }
 349         }
 350
 351         for ($i = 0, $cnt = count($bcc); $i < $cnt; $i++) {
 352             if (!$bcc[$i]->host) $bcc[$i]->host = $domain;
 353             if (strlen($bcc[$i]->mailbox)) {
 354                 fputs($stream, 'RCPT TO:<'.$bcc[$i]->mailbox.'@'.$bcc[$i]->host.">\r\n");
 355                 $tmp = fgets($stream, 1024);
 356                 if ($this->errorCheck($tmp, $stream)) {
 357                     return(0);
 358                 }
 359             }
 360         }
 361         /* Lets start sending the actual message */
 362         fputs($stream, "DATA\r\n");
 363         $tmp = fgets($stream, 1024);
 364         if ($this->errorCheck($tmp, $stream)) {
 365                 return(0);
 366         }
 367         return $stream;
 368     }
 369
 370     function finalizeStream($stream) {
 371         fputs($stream, "\r\n.\r\n"); /* end the DATA part */
 372         $tmp = fgets($stream, 1024);
 373         $this->errorCheck($tmp, $stream);
 374         if ($this->dlv_ret_nr != 250) {
 375                 return(0);
 376         }
 377         fputs($stream, "QUIT\r\n"); /* log off */
 378         fclose($stream);
 379         return true;
 380     }
 381
 382     /* check if an SMTP reply is an error and set an error message) */
 383     function errorCheck($line, $smtpConnection) {
 384
 385         $err_num = substr($line, 0, 3);
 386         $this->dlv_ret_nr = $err_num;
 387         $server_msg = substr($line, 4);
 388
 389         while(substr($line, 0, 4) == ($err_num.'-')) {
 390             $line = fgets($smtpConnection, 1024);
 391             $server_msg .= substr($line, 4);
 392         }
 393
 394         if ( ((int) $err_num{0}) < 4) {
 395             return false;
 396         }
 397
 398         switch ($err_num) {
 399         case '421': $message = _("Service not available, closing channel");
 400             break;
 401         case '432': $message = _("A password transition is needed");
 402             break;
 403         case '450': $message = _("Requested mail action not taken: mailbox unavailable");
 404             break;
 405         case '451': $message = _("Requested action aborted: error in processing");
 406             break;
 407         case '452': $message = _("Requested action not taken: insufficient system storage");
 408             break;
 409         case '454': $message = _("Temporary authentication failure");
 410             break;
 411         case '500': $message = _("Syntax error; command not recognized");
 412             break;
 413         case '501': $message = _("Syntax error in parameters or arguments");
 414             break;
 415         case '502': $message = _("Command not implemented");
 416             break;
 417         case '503': $message = _("Bad sequence of commands");
 418             break;
 419         case '504': $message = _("Command parameter not implemented");
 420             break;
 421         case '530': $message = _("Authentication required");
 422             break;
 423         case '534': $message = _("Authentication mechanism is too weak");
 424             break;
 425         case '535': $message = _("Authentication failed");
 426             break;
 427         case '538': $message = _("Encryption required for requested authentication mechanism");
 428             break;
 429         case '550': $message = _("Requested action not taken: mailbox unavailable");
 430             break;
 431         case '551': $message = _("User not local; please try forwarding");
 432             break;
 433         case '552': $message = _("Requested mail action aborted: exceeding storage allocation");
 434             break;
 435         case '553': $message = _("Requested action not taken: mailbox name not allowed");
 436             break;
 437         case '554': $message = _("Transaction failed");
 438             break;
 439         default:    $message = _("Unknown response");
 440             break;
 441         }
 442
 443         $this->dlv_msg = $message;
 444         $this->dlv_server_msg = $server_msg;
 445
 446         return true;
 447     }
 448
 449     function authPop($pop_server='', $pop_port='', $user, $pass) {
 450         if (!$pop_port) {
 451             $pop_port = 110;
 452         }
 453         if (!$pop_server) {
 454             $pop_server = 'localhost';
 455         }
 456         $popConnection = @fsockopen($pop_server, $pop_port, $err_no, $err_str);
 457         if (!$popConnection) {
 458             error_log("Error connecting to POP Server ($pop_server:$pop_port)"
 459                 . " $err_no : $err_str");
 460             return false;
 461         } else {
 462             $tmp = fgets($popConnection, 1024); /* banner */
 463             if (substr($tmp, 0, 3) != '+OK') {
 464                 return false;
 465             }
 466             fputs($popConnection, "USER $user\r\n");
 467             $tmp = fgets($popConnection, 1024);
 468             if (substr($tmp, 0, 3) != '+OK') {
 469                 return false;
 470             }
 471             fputs($popConnection, 'PASS ' . $pass . "\r\n");
 472             $tmp = fgets($popConnection, 1024);
 473             if (substr($tmp, 0, 3) != '+OK') {
 474                 return false;
 475             }
 476             fputs($popConnection, "QUIT\r\n"); /* log off */
 477             fclose($popConnection);
 478         }
 479         return true;
 480     }
 481
 482     /**
 483      * Parses ESMTP EHLO response (rfc1869)
 484      *
 485      * Reads SMTP response to EHLO command and fills class variables
 486      * (ehlo array and domain string). Returns last line.
 487      * @param stream $stream smtp connection stream.
 488      * @return string last ehlo line
 489      * @since 1.5.1
 490      */
 491     function parse_ehlo_response($stream) {
 492         // don't cache ehlo information
 493         $this->ehlo=array();
 494         $ret = '';
 495         $firstline = true;
 496         /**
 497          * ehlo mailclient.example.org
 498          * 250-mail.example.org
 499          * 250-PIPELINING
 500          * 250-SIZE 52428800
 501          * 250-DATAZ
 502          * 250-STARTTLS
 503          * 250-AUTH LOGIN PLAIN
 504          * 250 8BITMIME
 505          */
 506         while ($line=fgets($stream, 1024)){
 507             // match[1] = first symbol after 250
 508             // match[2] = domain or ehlo-keyword
 509             // match[3] = greeting or ehlo-param
 510             // match space after keyword in ehlo-keyword CR LF
 511             if (preg_match("/^250(-|\s)(\S*)\s+(\S.*)\r\n/",$line,$match)||
 512                 preg_match("/^250(-|\s)(\S*)\s*\r\n/",$line,$match)) {
 513                 if ($firstline) {
 514                     // first ehlo line (250[-\ ]domain SP greeting)
 515                     $this->domain = $match[2];
 516                     $firstline=false;
 517                 } elseif (!isset($match[3])) {
 518                     // simple one word extension
 519                     $this->ehlo[strtoupper($match[2])]='';
 520                 } elseif (!preg_match("/\s/",trim($match[3]))) {
 521                     // extension with one option
 522                     // yes, I know about ctype extension. no, i don't want to depend on it
 523                     $this->ehlo[strtoupper($match[2])]=trim($match[3]);
 524                 } else {
 525                     // ehlo-param with spaces
 526                     $this->ehlo[strtoupper($match[2])]=explode(' ',trim($match[3]));
 527                 }
 528                 if ($match[1]==' ') {
 529                     // stop while cycle, if we reach last 250 line
 530                     $ret = $line;
 531                     break;
 532                 }
 533             } else {
 534                 // this is not 250 response
 535                 $ret = $line;
 536                 break;
 537             }
 538         }
 539         return $ret;
 540     }
 541 }