'/[\d]{3} OK id=(.*)/', 'sendmail' => '/[\d]{3} 2\.0\.0 (.*) Message/', 'postfix' => '/[\d]{3} 2\.0\.0 Ok: queued as (.*)/', 'Microsoft_ESMTP' => '/[0-9]{3} 2\.[\d]\.0 (.*)@(?:.*) Queued mail for delivery/', 'Amazon_SES' => '/[\d]{3} Ok (.*)/', 'SendGrid' => '/[\d]{3} Ok: queued as (.*)/', 'CampaignMonitor' => '/[\d]{3} 2\.0\.0 OK:([a-zA-Z\d]{48})/', 'Haraka' => '/[\d]{3} Message Queued \((.*)\)/', 'ZoneMTA' => '/[\d]{3} Message queued as (.*)/', 'Mailjet' => '/[\d]{3} OK queued as (.*)/', ]; public static $xclient_allowed_attributes = [ 'NAME', 'ADDR', 'PORT', 'PROTO', 'HELO', 'LOGIN', 'DESTADDR', 'DESTPORT' ]; protected $last_smtp_transaction_id; protected $smtp_conn; protected $error = [ 'error' => '', 'detail' => '', 'smtp_code' => '', 'smtp_code_ex' => '', ]; protected $helo_rply; protected $server_caps; protected $last_reply = ''; protected function edebug($str, $level = 0) { if ($level > $this->do_debug) { return; } //Is this a PSR-3 logger? if ($this->Debugoutput instanceof \Psr\Log\LoggerInterface) { //Remove trailing line breaks potentially added by calls to SMTP::client_send() $this->Debugoutput->debug(rtrim($str, "\r\n")); return; } //Avoid clash with built-in function names if (is_callable($this->Debugoutput) && !in_array($this->Debugoutput, ['error_log', 'html', 'echo'])) { call_user_func($this->Debugoutput, $str, $level); return; } switch ($this->Debugoutput) { case 'error_log': //Don't output, just log error_log($str); break; case 'html': //Cleans up output a bit for a better looking, HTML-safe output echo gmdate('Y-m-d H:i:s'), ' ', htmlentities( preg_replace('/[\r\n]+/', '', $str), ENT_QUOTES, 'UTF-8' ), "
\n"; break; case 'echo': default: //Normalize line breaks $str = preg_replace('/\r\n|\r/m', "\n", $str); echo gmdate('Y-m-d H:i:s'), "\t", //Trim trailing space trim( //Indent for readability, except for trailing break str_replace( "\n", "\n \t ", trim($str) ) ), "\n"; } } public function connect($host, $port = null, $timeout = 30, $options = []) { //Clear errors to avoid confusion $this->setError(''); //Make sure we are __not__ connected if ($this->connected()) { //Already connected, generate error $this->setError('Already connected to a server'); return false; } if (empty($port)) { $port = self::DEFAULT_PORT; } //Connect to the SMTP server $this->edebug( "Connection: opening to $host:$port, timeout=$timeout, options=" . (count($options) > 0 ? var_export($options, true) : 'array()'), self::DEBUG_CONNECTION ); $this->smtp_conn = $this->getSMTPConnection($host, $port, $timeout, $options); if ($this->smtp_conn === false) { //Error info already set inside `getSMTPConnection()` return false; } $this->edebug('Connection: opened', self::DEBUG_CONNECTION); //Get any announcement $this->last_reply = $this->get_lines(); $this->edebug('SERVER -> CLIENT: ' . $this->last_reply, self::DEBUG_SERVER); $responseCode = (int)substr($this->last_reply, 0, 3); if ($responseCode === 220) { return true; } //Anything other than a 220 response means something went wrong //RFC 5321 says the server will wait for us to send a QUIT in response to a 554 error //https://www.rfc-editor.org/rfc/rfc5321#section-3.1 if ($responseCode === 554) { $this->quit(); } //This will handle 421 responses which may not wait for a QUIT (e.g. if the server is being shut down) $this->edebug('Connection: closing due to error', self::DEBUG_CONNECTION); $this->close(); return false; } protected function getSMTPConnection($host, $port = null, $timeout = 30, $options = []) { static $streamok; //This is enabled by default since 5.0.0 but some providers disable it //Check this once and cache the result if (null === $streamok) { $streamok = function_exists('stream_socket_client'); } $errno = 0; $errstr = ''; if ($streamok) { $socket_context = stream_context_create($options); set_error_handler(function () { call_user_func_array([$this, 'errorHandler'], func_get_args()); }); $connection = stream_socket_client( $host . ':' . $port, $errno, $errstr, $timeout, STREAM_CLIENT_CONNECT, $socket_context ); } else { //Fall back to fsockopen which should work in more places, but is missing some features $this->edebug( 'Connection: stream_socket_client not available, falling back to fsockopen', self::DEBUG_CONNECTION ); set_error_handler(function () { call_user_func_array([$this, 'errorHandler'], func_get_args()); }); $connection = fsockopen( $host, $port, $errno, $errstr, $timeout ); } restore_error_handler(); //Verify we connected properly if (!is_resource($connection)) { $this->setError( 'Failed to connect to server', '', (string) $errno, $errstr ); $this->edebug( 'SMTP ERROR: ' . $this->error['error'] . ": $errstr ($errno)", self::DEBUG_CLIENT ); return false; } //SMTP server can take longer to respond, give longer timeout for first read //Windows does not have support for this timeout function if (strpos(PHP_OS, 'WIN') !== 0) { $max = (int)ini_get('max_execution_time'); //Don't bother if unlimited, or if set_time_limit is disabled if (0 !== $max && $timeout > $max && strpos(ini_get('disable_functions'), 'set_time_limit') === false) { @set_time_limit($timeout); } stream_set_timeout($connection, $timeout, 0); } return $connection; } public function startTLS() { if (!$this->sendCommand('STARTTLS', 'STARTTLS', 220)) { return false; } //Allow the best TLS version(s) we can $crypto_method = STREAM_CRYPTO_METHOD_TLS_CLIENT; //PHP 5.6.7 dropped inclusion of TLS 1.1 and 1.2 in STREAM_CRYPTO_METHOD_TLS_CLIENT //so add them back in manually if we can if (defined('STREAM_CRYPTO_METHOD_TLSv1_2_CLIENT')) { $crypto_method |= STREAM_CRYPTO_METHOD_TLSv1_2_CLIENT; $crypto_method |= STREAM_CRYPTO_METHOD_TLSv1_1_CLIENT; } //Begin encrypted connection set_error_handler(function () { call_user_func_array([$this, 'errorHandler'], func_get_args()); }); $crypto_ok = stream_socket_enable_crypto( $this->smtp_conn, true, $crypto_method ); restore_error_handler(); return (bool) $crypto_ok; } public function authenticate( $username, $password, $authtype = null, $OAuth = null ) { if (!$this->server_caps) { $this->setError('Authentication is not allowed before HELO/EHLO'); return false; } if (array_key_exists('EHLO', $this->server_caps)) { //SMTP extensions are available; try to find a proper authentication method if (!array_key_exists('AUTH', $this->server_caps)) { $this->setError('Authentication is not allowed at this stage'); //'at this stage' means that auth may be allowed after the stage changes //e.g. after STARTTLS return false; } $this->edebug('Auth method requested: ' . ($authtype ?: 'UNSPECIFIED'), self::DEBUG_LOWLEVEL); $this->edebug( 'Auth methods available on the server: ' . implode(',', $this->server_caps['AUTH']), self::DEBUG_LOWLEVEL ); //If we have requested a specific auth type, check the server supports it before trying others if (null !== $authtype && !in_array($authtype, $this->server_caps['AUTH'], true)) { $this->edebug('Requested auth method not available: ' . $authtype, self::DEBUG_LOWLEVEL); $authtype = null; } if (empty($authtype)) { //If no auth mechanism is specified, attempt to use these, in this order //Try CRAM-MD5 first as it's more secure than the others foreach (['CRAM-MD5', 'LOGIN', 'PLAIN', 'XOAUTH2'] as $method) { if (in_array($method, $this->server_caps['AUTH'], true)) { $authtype = $method; break; } } if (empty($authtype)) { $this->setError('No supported authentication methods found'); return false; } $this->edebug('Auth method selected: ' . $authtype, self::DEBUG_LOWLEVEL); } if (!in_array($authtype, $this->server_caps['AUTH'], true)) { $this->setError("The requested authentication method \"$authtype\" is not supported by the server"); return false; } } elseif (empty($authtype)) { $authtype = 'LOGIN'; } switch ($authtype) { case 'PLAIN': //Start authentication if (!$this->sendCommand('AUTH', 'AUTH PLAIN', 334)) { return false; } //Send encoded username and password if ( //Format from https://www.rfc-editor.org/rfc/rfc4616#section-2 //We skip the first field (it's forgery), so the string starts with a null byte !$this->sendCommand( 'User & Password', base64_encode("\0" . $username . "\0" . $password), 235 ) ) { return false; } break; case 'LOGIN': //Start authentication if (!$this->sendCommand('AUTH', 'AUTH LOGIN', 334)) { return false; } if (!$this->sendCommand('Username', base64_encode($username), 334)) { return false; } if (!$this->sendCommand('Password', base64_encode($password), 235)) { return false; } break; case 'CRAM-MD5': //Start authentication if (!$this->sendCommand('AUTH CRAM-MD5', 'AUTH CRAM-MD5', 334)) { return false; } //Get the challenge $challenge = base64_decode(substr($this->last_reply, 4)); //Build the response $response = $username . ' ' . $this->hmac($challenge, $password); //send encoded credentials return $this->sendCommand('Username', base64_encode($response), 235); case 'XOAUTH2': //The OAuth instance must be set up prior to requesting auth. if (null === $OAuth) { return false; } $oauth = $OAuth->getOauth64(); //Start authentication if (!$this->sendCommand('AUTH', 'AUTH XOAUTH2 ' . $oauth, 235)) { return false; } break; default: $this->setError("Authentication method \"$authtype\" is not supported"); return false; } return true; } protected function hmac($data, $key) { if (function_exists('hash_hmac')) { return hash_hmac('md5', $data, $key); } //The following borrowed from //https://www.php.net/manual/en/function.mhash.php#27225 //RFC 2104 HMAC implementation for php. //Creates an md5 HMAC. //Eliminates the need to install mhash to compute a HMAC //by Lance Rushing $bytelen = 64; //byte length for md5 if (strlen($key) > $bytelen) { $key = pack('H*', md5($key)); } $key = str_pad($key, $bytelen, chr(0x00)); $ipad = str_pad('', $bytelen, chr(0x36)); $opad = str_pad('', $bytelen, chr(0x5c)); $k_ipad = $key ^ $ipad; $k_opad = $key ^ $opad; return md5($k_opad . pack('H*', md5($k_ipad . $data))); } public function connected() { if (is_resource($this->smtp_conn)) { $sock_status = stream_get_meta_data($this->smtp_conn); if ($sock_status['eof']) { //The socket is valid but we are not connected $this->edebug( 'SMTP NOTICE: EOF caught while checking if connected', self::DEBUG_CLIENT ); $this->close(); return false; } return true; //everything looks good } return false; } public function close() { $this->server_caps = null; $this->helo_rply = null; if (is_resource($this->smtp_conn)) { //Close the connection and cleanup fclose($this->smtp_conn); $this->smtp_conn = null; //Makes for cleaner serialization $this->edebug('Connection: closed', self::DEBUG_CONNECTION); } } public function data($msg_data) { //This will use the standard timelimit if (!$this->sendCommand('DATA', 'DATA', 354)) { return false; } /* The server is ready to accept data! * According to rfc821 we should not send more than 1000 characters on a single line (including the LE) * so we will break the data up into lines by \r and/or \n then if needed we will break each of those into * smaller lines to fit within the limit. * We will also look for lines that start with a '.' and prepend an additional '.'. * NOTE: this does not count towards line-length limit. */ //Normalize line breaks before exploding $lines = explode("\n", str_replace(["\r\n", "\r"], "\n", $msg_data)); /* To distinguish between a complete RFC822 message and a plain message body, we check if the first field * of the first line (':' separated) does not contain a space then it _should_ be a header, and we will * process all lines before a blank line as headers. */ $field = substr($lines[0], 0, strpos($lines[0], ':')); $in_headers = false; if (!empty($field) && strpos($field, ' ') === false) { $in_headers = true; } foreach ($lines as $line) { $lines_out = []; if ($in_headers && $line === '') { $in_headers = false; } //Break this line up into several smaller lines if it's too long //Micro-optimisation: isset($str[$len]) is faster than (strlen($str) > $len), while (isset($line[self::MAX_LINE_LENGTH])) { //Working backwards, try to find a space within the last MAX_LINE_LENGTH chars of the line to break on //so as to avoid breaking in the middle of a word $pos = strrpos(substr($line, 0, self::MAX_LINE_LENGTH), ' '); //Deliberately matches both false and 0 if (!$pos) { //No nice break found, add a hard break $pos = self::MAX_LINE_LENGTH - 1; $lines_out[] = substr($line, 0, $pos); $line = substr($line, $pos); } else { //Break at the found point $lines_out[] = substr($line, 0, $pos); //Move along by the amount we dealt with $line = substr($line, $pos + 1); } //If processing headers add a LWSP-char to the front of new line RFC822 section 3.1.1 if ($in_headers) { $line = "\t" . $line; } } $lines_out[] = $line; //Send the lines to the server foreach ($lines_out as $line_out) { //Dot-stuffing as per RFC5321 section 4.5.2 //https://www.rfc-editor.org/rfc/rfc5321#section-4.5.2 if (!empty($line_out) && $line_out[0] === '.') { $line_out = '.' . $line_out; } $this->client_send($line_out . static::LE, 'DATA'); } } //Message data has been sent, complete the command //Increase timelimit for end of DATA command $savetimelimit = $this->Timelimit; $this->Timelimit *= 2; $result = $this->sendCommand('DATA END', '.', 250); $this->recordLastTransactionID(); //Restore timelimit $this->Timelimit = $savetimelimit; return $result; } public function hello($host = '') { //Try extended hello first (RFC 2821) if ($this->sendHello('EHLO', $host)) { return true; } //Some servers shut down the SMTP service here (RFC 5321) if (substr($this->helo_rply, 0, 3) == '421') { return false; } return $this->sendHello('HELO', $host); } protected function sendHello($hello, $host) { $noerror = $this->sendCommand($hello, $hello . ' ' . $host, 250); $this->helo_rply = $this->last_reply; if ($noerror) { $this->parseHelloFields($hello); } else { $this->server_caps = null; } return $noerror; } protected function parseHelloFields($type) { $this->server_caps = []; $lines = explode("\n", $this->helo_rply); foreach ($lines as $n => $s) { //First 4 chars contain response code followed by - or space $s = trim(substr($s, 4)); if (empty($s)) { continue; } $fields = explode(' ', $s); if (!empty($fields)) { if (!$n) { $name = $type; $fields = $fields[0]; } else { $name = array_shift($fields); switch ($name) { case 'SIZE': $fields = ($fields ? $fields[0] : 0); break; case 'AUTH': if (!is_array($fields)) { $fields = []; } break; default: $fields = true; } } $this->server_caps[$name] = $fields; } } } public function mail($from) { $useVerp = ($this->do_verp ? ' XVERP' : ''); return $this->sendCommand( 'MAIL FROM', 'MAIL FROM:<' . $from . '>' . $useVerp, 250 ); } public function quit($close_on_error = true) { $noerror = $this->sendCommand('QUIT', 'QUIT', 221); $err = $this->error; //Save any error if ($noerror || $close_on_error) { $this->close(); $this->error = $err; //Restore any error from the quit command } return $noerror; } public function recipient($address, $dsn = '') { if (empty($dsn)) { $rcpt = 'RCPT TO:<' . $address . '>'; } else { $dsn = strtoupper($dsn); $notify = []; if (strpos($dsn, 'NEVER') !== false) { $notify[] = 'NEVER'; } else { foreach (['SUCCESS', 'FAILURE', 'DELAY'] as $value) { if (strpos($dsn, $value) !== false) { $notify[] = $value; } } } $rcpt = 'RCPT TO:<' . $address . '> NOTIFY=' . implode(',', $notify); } return $this->sendCommand( 'RCPT TO', $rcpt, [250, 251] ); } public function xclient(array $vars) { $xclient_options = ""; foreach ($vars as $key => $value) { if (in_array($key, SMTP::$xclient_allowed_attributes)) { $xclient_options .= " {$key}={$value}"; } } if (!$xclient_options) { return true; } return $this->sendCommand('XCLIENT', 'XCLIENT' . $xclient_options, 250); } public function reset() { return $this->sendCommand('RSET', 'RSET', 250); } protected function sendCommand($command, $commandstring, $expect) { if (!$this->connected()) { $this->setError("Called $command without being connected"); return false; } //Reject line breaks in all commands if ((strpos($commandstring, "\n") !== false) || (strpos($commandstring, "\r") !== false)) { $this->setError("Command '$command' contained line breaks"); return false; } $this->client_send($commandstring . static::LE, $command); $this->last_reply = $this->get_lines(); //Fetch SMTP code and possible error code explanation $matches = []; if (preg_match('/^([\d]{3})[ -](?:([\d]\\.[\d]\\.[\d]{1,2}) )?/', $this->last_reply, $matches)) { $code = (int) $matches[1]; $code_ex = (count($matches) > 2 ? $matches[2] : null); //Cut off error code from each response line $detail = preg_replace( "/{$code}[ -]" . ($code_ex ? str_replace('.', '\\.', $code_ex) . ' ' : '') . '/m', '', $this->last_reply ); } else { //Fall back to simple parsing if regex fails $code = (int) substr($this->last_reply, 0, 3); $code_ex = null; $detail = substr($this->last_reply, 4); } $this->edebug('SERVER -> CLIENT: ' . $this->last_reply, self::DEBUG_SERVER); if (!in_array($code, (array) $expect, true)) { $this->setError( "$command command failed", $detail, $code, $code_ex ); $this->edebug( 'SMTP ERROR: ' . $this->error['error'] . ': ' . $this->last_reply, self::DEBUG_CLIENT ); return false; } //Don't clear the error store when using keepalive if ($command !== 'RSET') { $this->setError(''); } return true; } public function sendAndMail($from) { return $this->sendCommand('SAML', "SAML FROM:$from", 250); } public function verify($name) { return $this->sendCommand('VRFY', "VRFY $name", [250, 251]); } public function noop() { return $this->sendCommand('NOOP', 'NOOP', 250); } public function turn() { $this->setError('The SMTP TURN command is not implemented'); $this->edebug('SMTP NOTICE: ' . $this->error['error'], self::DEBUG_CLIENT); return false; } public function client_send($data, $command = '') { //If SMTP transcripts are left enabled, or debug output is posted online //it can leak credentials, so hide credentials in all but lowest level if ( self::DEBUG_LOWLEVEL > $this->do_debug && in_array($command, ['User & Password', 'Username', 'Password'], true) ) { $this->edebug('CLIENT -> SERVER: [credentials hidden]', self::DEBUG_CLIENT); } else { $this->edebug('CLIENT -> SERVER: ' . $data, self::DEBUG_CLIENT); } set_error_handler(function () { call_user_func_array([$this, 'errorHandler'], func_get_args()); }); $result = fwrite($this->smtp_conn, $data); restore_error_handler(); return $result; } public function getError() { return $this->error; } public function getServerExtList() { return $this->server_caps; } public function getServerExt($name) { if (!$this->server_caps) { $this->setError('No HELO/EHLO was sent'); return null; } if (!array_key_exists($name, $this->server_caps)) { if ('HELO' === $name) { return $this->server_caps['EHLO']; } if ('EHLO' === $name || array_key_exists('EHLO', $this->server_caps)) { return false; } $this->setError('HELO handshake was used; No information about server extensions available'); return null; } return $this->server_caps[$name]; } public function getLastReply() { return $this->last_reply; } protected function get_lines() { //If the connection is bad, give up straight away if (!is_resource($this->smtp_conn)) { return ''; } $data = ''; $endtime = 0; stream_set_timeout($this->smtp_conn, $this->Timeout); if ($this->Timelimit > 0) { $endtime = time() + $this->Timelimit; } $selR = [$this->smtp_conn]; $selW = null; while (is_resource($this->smtp_conn) && !feof($this->smtp_conn)) { //Must pass vars in here as params are by reference //solution for signals inspired by https://github.com/symfony/symfony/pull/6540 set_error_handler(function () { call_user_func_array([$this, 'errorHandler'], func_get_args()); }); $n = stream_select($selR, $selW, $selW, $this->Timelimit); restore_error_handler(); if ($n === false) { $message = $this->getError()['detail']; $this->edebug( 'SMTP -> get_lines(): select failed (' . $message . ')', self::DEBUG_LOWLEVEL ); //stream_select returns false when the `select` system call is interrupted //by an incoming signal, try the select again if (stripos($message, 'interrupted system call') !== false) { $this->edebug( 'SMTP -> get_lines(): retrying stream_select', self::DEBUG_LOWLEVEL ); $this->setError(''); continue; } break; } if (!$n) { $this->edebug( 'SMTP -> get_lines(): select timed-out in (' . $this->Timelimit . ' sec)', self::DEBUG_LOWLEVEL ); break; } //Deliberate noise suppression - errors are handled afterwards $str = @fgets($this->smtp_conn, self::MAX_REPLY_LENGTH); $this->edebug('SMTP INBOUND: "' . trim($str) . '"', self::DEBUG_LOWLEVEL); $data .= $str; //If response is only 3 chars (not valid, but RFC5321 S4.2 says it must be handled), //or 4th character is a space or a line break char, we are done reading, break the loop. //String array access is a significant micro-optimisation over strlen if (!isset($str[3]) || $str[3] === ' ' || $str[3] === "\r" || $str[3] === "\n") { break; } //Timed-out? Log and break $info = stream_get_meta_data($this->smtp_conn); if ($info['timed_out']) { $this->edebug( 'SMTP -> get_lines(): stream timed-out (' . $this->Timeout . ' sec)', self::DEBUG_LOWLEVEL ); break; } //Now check if reads took too long if ($endtime && time() > $endtime) { $this->edebug( 'SMTP -> get_lines(): timelimit reached (' . $this->Timelimit . ' sec)', self::DEBUG_LOWLEVEL ); break; } } return $data; } public function setVerp($enabled = false) { $this->do_verp = $enabled; } public function getVerp() { return $this->do_verp; } protected function setError($message, $detail = '', $smtp_code = '', $smtp_code_ex = '') { $this->error = [ 'error' => $message, 'detail' => $detail, 'smtp_code' => $smtp_code, 'smtp_code_ex' => $smtp_code_ex, ]; } public function setDebugOutput($method = 'echo') { $this->Debugoutput = $method; } public function getDebugOutput() { return $this->Debugoutput; } public function setDebugLevel($level = 0) { $this->do_debug = $level; } public function getDebugLevel() { return $this->do_debug; } public function setTimeout($timeout = 0) { $this->Timeout = $timeout; } public function getTimeout() { return $this->Timeout; } protected function errorHandler($errno, $errmsg, $errfile = '', $errline = 0) { $notice = 'Connection failed.'; $this->setError( $notice, $errmsg, (string) $errno ); $this->edebug( "$notice Error #$errno: $errmsg [$errfile line $errline]", self::DEBUG_CONNECTION ); } protected function recordLastTransactionID() { $reply = $this->getLastReply(); if (empty($reply)) { $this->last_smtp_transaction_id = null; } else { $this->last_smtp_transaction_id = false; foreach ($this->smtp_transaction_id_patterns as $smtp_transaction_id_pattern) { $matches = []; if (preg_match($smtp_transaction_id_pattern, $reply, $matches)) { $this->last_smtp_transaction_id = trim($matches[1]); break; } } } return $this->last_smtp_transaction_id; } public function getLastTransactionID() { return $this->last_smtp_transaction_id; } }