<?php
/**
* PHPMailer RFC821 SMTP email transport class.
* PHP Version 5.5.
*
* @see https://github.com/PHPMailer/PHPMailer/ The PHPMailer GitHub project
*
* @author Marcus Bointon (Synchro/coolbru) <phpmailer@synchromedia.co.uk>
* @author Jim Jagielski (jimjag) <jimjag@gmail.com>
* @author Andy Prevost (codeworxtech) <codeworxtech@users.sourceforge.net>
* @author Brent R. Matzelle (original founder)
* @copyright 2012 - 2020 Marcus Bointon
* @copyright 2010 - 2012 Jim Jagielski
* @copyright 2004 - 2009 Andy Prevost
* @license https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html GNU Lesser General Public License
* @note This program is distributed in the hope that it will be useful - WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE.
*/
namespace PHPMailer\PHPMailer;
/**
* PHPMailer RFC821 SMTP email transport class.
* Implements RFC 821 SMTP commands and provides some utility methods for sending mail to an SMTP server.
*
* @author Chris Ryan
* @author Marcus Bointon <phpmailer@synchromedia.co.uk>
*/
class SMTP
{
/**
* The PHPMailer SMTP version number.
*
* @var string
*/
const VERSION = '6.9.3';
/**
* SMTP line break constant.
*
* @var string
*/
const LE = "\r\n";
/**
* The SMTP port to use if one is not specified.
*
* @var int
*/
const DEFAULT_PORT = 25;
/**
* The SMTPs port to use if one is not specified.
*
* @var int
*/
const DEFAULT_SECURE_PORT = 465;
/**
* The maximum line length allowed by RFC 5321 section 4.5.3.1.6,
* *excluding* a trailing CRLF break.
*
* @see https://www.rfc-editor.org/rfc/rfc5321#section-4.5.3.1.6
*
* @var int
*/
const MAX_LINE_LENGTH = 998;
/**
* The maximum line length allowed for replies in RFC 5321 section 4.5.3.1.5,
* *including* a trailing CRLF line break.
*
* @see https://www.rfc-editor.org/rfc/rfc5321#section-4.5.3.1.5
*
* @var int
*/
const MAX_REPLY_LENGTH = 512;
/**
* Debug level for no output.
*
* @var int
*/
const DEBUG_OFF = 0;
/**
* Debug level to show client -> server messages.
*
* @var int
*/
const DEBUG_CLIENT = 1;
/**
* Debug level to show client -> server and server -> client messages.
*
* @var int
*/
const DEBUG_SERVER = 2;
/**
* Debug level to show connection status, client -> server and server -> client messages.
*
* @var int
*/
const DEBUG_CONNECTION = 3;
/**
* Debug level to show all messages.
*
* @var int
*/
const DEBUG_LOWLEVEL = 4;
/**
* Debug output level.
* Options:
* * self::DEBUG_OFF (`0`) No debug output, default
* * self::DEBUG_CLIENT (`1`) Client commands
* * self::DEBUG_SERVER (`2`) Client commands and server responses
* * self::DEBUG_CONNECTION (`3`) As DEBUG_SERVER plus connection status
* * self::DEBUG_LOWLEVEL (`4`) Low-level data output, all messages.
*
* @var int
*/
public $do_debug = self::DEBUG_OFF;
/**
* How to handle debug output.
* Options:
* * `echo` Output plain-text as-is, appropriate for CLI
* * `html` Output escaped, line breaks converted to `<br>`, appropriate for browser output
* * `error_log` Output to error log as configured in php.ini
* Alternatively, you can provide a callable expecting two params: a message string and the debug level:
*
* ```php
* $smtp->Debugoutput = function($str, $level) {echo "debug level $level; message: $str";};
* ```
*
* Alternatively, you can pass in an instance of a PSR-3 compatible logger, though only `debug`
* level output is used:
*
* ```php
* $mail->Debugoutput = new myPsr3Logger;
* ```
*
* @var string|callable|\Psr\Log\LoggerInterface
*/
public $Debugoutput = 'echo';
/**
* Whether to use VERP.
*
* @see https://en.wikipedia.org/wiki/Variable_envelope_return_path
* @see https://www.postfix.org/VERP_README.html Info on VERP
*
* @var bool
*/
public $do_verp = false;
/**
* The timeout value for connection, in seconds.
* Default of 5 minutes (300sec) is from RFC2821 section 4.5.3.2.
* This needs to be quite high to function correctly with hosts using greetdelay as an anti-spam measure.
*
* @see https://www.rfc-editor.org/rfc/rfc2821#section-4.5.3.2
*
* @var int
*/
public $Timeout = 300;
/**
* How long to wait for commands to complete, in seconds.
* Default of 5 minutes (300sec) is from RFC2821 section 4.5.3.2.
*
* @var int
*/
public $Timelimit = 300;
/**
* Patterns to extract an SMTP transaction id from reply to a DATA command.
* The first capture group in each regex will be used as the ID.
* MS ESMTP returns the message ID, which may not be correct for internal tracking.
*
* @var string[]
*/
protected $smtp_transaction_id_patterns = [
'exim' => '/[\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 (.*)/',
];
/**
* Allowed SMTP XCLIENT attributes.
* Must be allowed by the SMTP server. EHLO response is not checked.
*
* @see https://www.postfix.org/XCLIENT_README.html
*
* @var array
*/
public static $xclient_allowed_attributes = [
'NAME', 'ADDR', 'PORT', 'PROTO', 'HELO', 'LOGIN', 'DESTADDR', 'DESTPORT'
];
/**
* The last transaction ID issued in response to a DATA command,
* if one was detected.
*
* @var string|bool|null
*/
protected $last_smtp_transaction_id;
/**
* The socket for the server connection.
*
* @var ?resource
*/
protected $smtp_conn;
/**
* Error information, if any, for the last SMTP command.
*
* @var array
*/
protected $error = [
'error' => '',
'detail' => '',
'smtp_code' => '',
'smtp_code_ex' => '',
];
/**
* The reply the server sent to us for HELO.
* If null, no HELO string has yet been received.
*
* @var string|null
*/
protected $helo_rply;
/**
* The set of SMTP extensions sent in reply to EHLO command.
* Indexes of the array are extension names.
* Value at index 'HELO' or 'EHLO' (according to command that was sent)
* represents the server name. In case of HELO it is the only element of the array.
* Other values can be boolean TRUE or an array containing extension options.
* If null, no HELO/EHLO string has yet been received.
*
* @var array|null
*/
protected $server_caps;
/**
* The most recent reply received from the server.
*
* @var string
*/
protected $last_reply = '';
/**
* Output debugging info via a user-selected method.
*
* @param string $str Debug string to output
* @param int $level The debug level of this message; see DEBUG_* constants
*
* @see SMTP::$Debugoutput
* @see SMTP::$do_debug
*/
protected function edebug($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
/** @noinspection ForgottenDebugOutputInspection */
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'
), "<br>\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";
}
}
/**
* Connect to an SMTP server.
*
* @param string $host SMTP server IP or host name
* @param int $port The port number to connect to
* @param int $timeout How long to wait for the connection to open
* @param array $options An array of options for stream_context_create()
*
* @return bool
*/
public function connect($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;
}
/**
* Create connection to the SMTP server.
*
* @param string $host SMTP server IP or host name
* @param int $port The port number to connect to
* @param int $timeout How long to wait for the connection to open
* @param array $options An array of options for stream_context_create()
*
* @return false|resource
*/
protected function getSMTPConnection($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 $connection;
}
/**
* Initiate a TLS (encrypted) session.
*
* @return bool
*/
public function startTLS()
{
if (!$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;
}
/**
* Perform SMTP authentication.
* Must be run after hello().
*
* @see hello()
*
* @param string $username The user name
* @param string $password The password
* @param string $authtype The auth type (CRAM-MD5, PLAIN, LOGIN, XOAUTH2)
* @param OAuthTokenProvider $OAuth An optional OAuthTokenProvider instance for XOAUTH2 authentication
*
* @return bool True if successfully authenticated
*/
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;
}
/**
* Calculate an MD5 HMAC hash.
* Works like hash_hmac('md5', $data, $key)
* in case that function is not available.
*
* @param string $data The data to hash
* @param string $key The key to hash with
*
* @return string
*/
protected function hmac($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 . $data)));
}
/**
* Check connection state.
*
* @return bool True if connected
*/
public function connected()
{
if (is_resource($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;
}
/**
* Close the socket and clean up the state of the class.
* Don't use this function without first trying to use QUIT.
*
* @see quit()
*/
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);
}
}
/**
* Send an SMTP DATA command.
* Issues a data command and sends the msg_data to the server,
* finalizing the mail transaction. $msg_data is the message
* that is to be sent with the headers. Each header needs to be
* on a single line followed by a <CRLF> with the message headers
* and the message body being separated by an additional <CRLF>.
* Implements RFC 821: DATA <CRLF>.
*
* @param string $msg_data Message data to send
*
* @return bool
*/
public function data($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;
}
/**
* Send an SMTP HELO or EHLO command.
* Used to identify the sending server to the receiving server.
* This makes sure that client and server are in a known state.
* Implements RFC 821: HELO <SP> <domain> <CRLF>
* and RFC 2821 EHLO.
*
* @param string $host The host name or IP to connect to
*
* @return bool
*/
public function hello($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);
}
/**
* Send an SMTP HELO or EHLO command.
* Low-level implementation used by hello().
*
* @param string $hello The HELO string
* @param string $host The hostname to say we are
*
* @return bool
*
* @see hello()
*/
protected function sendHello($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;
}
/**
* Parse a reply to HELO/EHLO command to discover server extensions.
* In case of HELO, the only parameter that can be discovered is a server name.
*
* @param string $type `HELO` or `EHLO`
*/
protected function parseHelloFields($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;
}
}
}
/**
* Send an SMTP MAIL command.
* Starts a mail transaction from the email address specified in
* $from. Returns true if successful or false otherwise. If True
* the mail transaction is started and then one or more recipient
* commands may be called followed by a data command.
* Implements RFC 821: MAIL <SP> FROM:<reverse-path> <CRLF>.
*
* @param string $from Source address of this message
*
* @return bool
*/
public function mail($from)
{
$useVerp = ($this->do_verp ? ' XVERP' : '');
return $this->sendCommand(
'MAIL FROM',
'MAIL FROM:<' . $from . '>' . $useVerp,
250
);
}
/**
* Send an SMTP QUIT command.
* Closes the socket if there is no error or the $close_on_error argument is true.
* Implements from RFC 821: QUIT <CRLF>.
*
* @param bool $close_on_error Should the connection close if an error occurs?
*
* @return bool
*/
public function quit($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;
}
/**
* Send an SMTP RCPT command.
* Sets the TO argument to $toaddr.
* Returns true if the recipient was accepted false if it was rejected.
* Implements from RFC 821: RCPT <SP> TO:<forward-path> <CRLF>.
*
* @param string $address The address the message is being sent to
* @param string $dsn Comma separated list of DSN notifications. NEVER, SUCCESS, FAILURE
* or DELAY. If you specify NEVER all other notifications are ignored.
*
* @return bool
*/
public function recipient($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]
);
}
/**
* Send SMTP XCLIENT command to server and check its return code.
*
* @return bool True on success
*/
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);
}
/**
* Send an SMTP RSET command.
* Abort any transaction that is currently in progress.
* Implements RFC 821: RSET <CRLF>.
*
* @return bool True on success
*/
public function reset()
{
return $this->sendCommand('RSET', 'RSET', 250);
}
/**
* Send a command to an SMTP server and check its return code.
*
* @param string $command The command name - not sent to the server
* @param string $commandstring The actual command to send
* @param int|array $expect One or more expected integer success codes
*
* @return bool True on success
*/
protected function sendCommand($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;
}
/**
* Send an SMTP SAML command.
* Starts a mail transaction from the email address specified in $from.
* Returns true if successful or false otherwise. If True
* the mail transaction is started and then one or more recipient
* commands may be called followed by a data command. This command
* will send the message to the users terminal if they are logged
* in and send them an email.
* Implements RFC 821: SAML <SP> FROM:<reverse-path> <CRLF>.
*
* @param string $from The address the message is from
*
* @return bool
*/
public function sendAndMail($from)
{
return $this->sendCommand('SAML', "SAML FROM:$from", 250);
}
/**
* Send an SMTP VRFY command.
*
* @param string $name The name to verify
*
* @return bool
*/
public function verify($name)
{
return $this->sendCommand('VRFY', "VRFY $name", [250, 251]);
}
/**
* Send an SMTP NOOP command.
* Used to keep keep-alives alive, doesn't actually do anything.
*
* @return bool
*/
public function noop()
{
return $this->sendCommand('NOOP', 'NOOP', 250);
}
/**
* Send an SMTP TURN command.
* This is an optional command for SMTP that this class does not support.
* This method is here to make the RFC821 Definition complete for this class
* and _may_ be implemented in future.
* Implements from RFC 821: TURN <CRLF>.
*
* @return bool
*/
public function turn()
{
$this->setError('The SMTP TURN command is not implemented');
$this->edebug('SMTP NOTICE: ' . $this->error['error'], self::DEBUG_CLIENT);
return false;
}
/**
* Send raw data to the server.
*
* @param string $data The data to send
* @param string $command Optionally, the command this is part of, used only for controlling debug output
*
* @return int|bool The number of bytes sent to the server or false on error
*/
public function client_send($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;
}
/**
* Get the latest error.
*
* @return array
*/
public function getError()
{
return $this->error;
}
/**
* Get SMTP extensions available on the server.
*
* @return array|null
*/
public function getServerExtList()
{
return $this->server_caps;
}
/**
* Get metadata about the SMTP server from its HELO/EHLO response.
* The method works in three ways, dependent on argument value and current state:
* 1. HELO/EHLO has not been sent - returns null and populates $this->error.
* 2. HELO has been sent -
* $name == 'HELO': returns server name
* $name == 'EHLO': returns boolean false
* $name == any other string: returns null and populates $this->error
* 3. EHLO has been sent -
* $name == 'HELO'|'EHLO': returns the server name
* $name == any other string: if extension $name exists, returns True
* or its options (e.g. AUTH mechanisms supported). Otherwise returns False.
*
* @param string $name Name of SMTP extension or 'HELO'|'EHLO'
*
* @return string|bool|null
*/
public function getServerExt($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];
}
/**
* Get the last reply from the server.
*
* @return string
*/
public function getLastReply()
{
return $this->last_reply;
}
/**
* Read the SMTP server's response.
* Either before eof or socket timeout occurs on the operation.
* With SMTP we can tell if we have more lines to read if the
* 4th character is '-' symbol. If it is a space then we don't
* need to read anything else.
*
* @return string
*/
protected function get_lines()
{
//If the connection is bad, give up straight away
if (!is_resource($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;
}
/**
* Enable or disable VERP address generation.
*
* @param bool $enabled
*/
public function setVerp($enabled = false)
{
$this->do_verp = $enabled;
}
/**
* Get VERP address generation mode.
*
* @return bool
*/
public function getVerp()
{
return $this->do_verp;
}
/**
* Set error messages and codes.
*
* @param string $message The error message
* @param string $detail Further detail on the error
* @param string $smtp_code An associated SMTP error code
* @param string $smtp_code_ex Extended SMTP code
*/
protected function setError($message, $detail = '', $smtp_code = '', $smtp_code_ex = '')
{
$this->error = [
'error' => $message,
'detail' => $detail,
'smtp_code' => $smtp_code,
'smtp_code_ex' => $smtp_code_ex,
];
}
/**
* Set debug output method.
*
* @param string|callable $method The name of the mechanism to use for debugging output, or a callable to handle it
*/
public function setDebugOutput($method = 'echo')
{
$this->Debugoutput = $method;
}
/**
* Get debug output method.
*
* @return string
*/
public function getDebugOutput()
{
return $this->Debugoutput;
}
/**
* Set debug output level.
*
* @param int $level
*/
public function setDebugLevel($level = 0)
{
$this->do_debug = $level;
}
/**
* Get debug output level.
*
* @return int
*/
public function getDebugLevel()
{
return $this->do_debug;
}
/**
* Set SMTP timeout.
*
* @param int $timeout The timeout duration in seconds
*/
public function setTimeout($timeout = 0)
{
$this->Timeout = $timeout;
}
/**
* Get SMTP timeout.
*
* @return int
*/
public function getTimeout()
{
return $this->Timeout;
}
/**
* Reports an error number and string.
*
* @param int $errno The error number returned by PHP
* @param string $errmsg The error message returned by PHP
* @param string $errfile The file the error occurred in
* @param int $errline The line number the error occurred on
*/
protected function errorHandler($errno, $errmsg, $errfile = '', $errline = 0)
{
$notice = 'Connection failed.';
$this->setError(
$notice,
$errmsg,
(string) $errno
);
$this->edebug(
"$notice Error #$errno: $errmsg [$errfile line $errline]",
self::DEBUG_CONNECTION
);
}
/**
* Extract and return the ID of the last SMTP transaction based on
* a list of patterns provided in SMTP::$smtp_transaction_id_patterns.
* Relies on the host providing the ID in response to a DATA command.
* If no reply has been received yet, it will return null.
* If no pattern was matched, it will return false.
*
* @return bool|string|null
*/
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;
}
/**
* Get the queue/transaction ID of the last SMTP transaction
* If no reply has been received yet, it will return null.
* If no pattern was matched, it will return false.
*
* @return bool|string|null
*
* @see recordLastTransactionID()
*/
public function getLastTransactionID()
{
return $this->last_smtp_transaction_id;
}
}