<?php
/**
* CakePHP(tm) : Rapid Development Framework (https://cakephp.org)
* Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
*
* Licensed under The MIT License
* For full copyright and license information, please see the LICENSE.txt
* Redistributions of files must retain the above copyright notice.
*
* @copyright Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
* @link https://cakephp.org CakePHP(tm) Project
* @since 2.0.0
* @license https://opensource.org/licenses/mit-license.php MIT License
*/
namespace Cake\Mailer\Transport;
use Cake\Mailer\AbstractTransport;
use Cake\Mailer\Email;
use Cake\Network\Exception\SocketException;
use Cake\Network\Socket;
use Exception;
/**
* Send mail using SMTP protocol
*/
class SmtpTransport extends AbstractTransport
{
/**
* Default config for this class
*
* @var array
*/
protected $_defaultConfig = [
'host' => 'localhost',
'port' => 25,
'timeout' => 30,
'username' => null,
'password' => null,
'client' => null,
'tls' => false,
'keepAlive' => false,
];
/**
* Socket to SMTP server
*
* @var \Cake\Network\Socket|null
*/
protected $_socket;
/**
* Content of email to return
*
* @var array
*/
protected $_content = [];
/**
* The response of the last sent SMTP command.
*
* @var array
*/
protected $_lastResponse = [];
/**
* Destructor
*
* Tries to disconnect to ensure that the connection is being
* terminated properly before the socket gets closed.
*/
public function __destruct()
{
try {
$this->disconnect();
} catch (Exception $e) {
// avoid fatal error on script termination
}
}
/**
* Unserialize handler.
*
* Ensure that the socket property isn't reinitialized in a broken state.
*
* @return void
*/
public function __wakeup()
{
$this->_socket = null;
}
/**
* Connect to the SMTP server.
*
* This method tries to connect only in case there is no open
* connection available already.
*
* @return void
*/
public function connect()
{
if (!$this->connected()) {
$this->_connect();
$this->_auth();
}
}
/**
* Check whether an open connection to the SMTP server is available.
*
* @return bool
*/
public function connected()
{
return $this->_socket !== null && $this->_socket->connected;
}
/**
* Disconnect from the SMTP server.
*
* This method tries to disconnect only in case there is an open
* connection available.
*
* @return void
*/
public function disconnect()
{
if ($this->connected()) {
$this->_disconnect();
}
}
/**
* Returns the response of the last sent SMTP command.
*
* A response consists of one or more lines containing a response
* code and an optional response message text:
* ```
* [
* [
* 'code' => '250',
* 'message' => 'mail.example.com'
* ],
* [
* 'code' => '250',
* 'message' => 'PIPELINING'
* ],
* [
* 'code' => '250',
* 'message' => '8BITMIME'
* ],
* // etc...
* ]
* ```
*
* @return array
*/
public function getLastResponse()
{
return $this->_lastResponse;
}
/**
* Send mail
*
* @param \Cake\Mailer\Email $email Email instance
* @return array
* @throws \Cake\Network\Exception\SocketException
*/
public function send(Email $email)
{
if (!$this->connected()) {
$this->_connect();
$this->_auth();
} else {
$this->_smtpSend('RSET');
}
$this->_sendRcpt($email);
$this->_sendData($email);
if (!$this->_config['keepAlive']) {
$this->_disconnect();
}
return $this->_content;
}
/**
* Parses and stores the response lines in `'code' => 'message'` format.
*
* @param string[] $responseLines Response lines to parse.
* @return void
*/
protected function _bufferResponseLines(array $responseLines)
{
$response = [];
foreach ($responseLines as $responseLine) {
if (preg_match('/^(\d{3})(?:[ -]+(.*))?$/', $responseLine, $match)) {
$response[] = [
'code' => $match[1],
'message' => isset($match[2]) ? $match[2] : null,
];
}
}
$this->_lastResponse = array_merge($this->_lastResponse, $response);
}
/**
* Connect to SMTP Server
*
* @return void
* @throws \Cake\Network\Exception\SocketException
*/
protected function _connect()
{
$this->_generateSocket();
if (!$this->_socket->connect()) {
throw new SocketException('Unable to connect to SMTP server.');
}
$this->_smtpSend(null, '220');
$config = $this->_config;
if (isset($config['client'])) {
$host = $config['client'];
} elseif ($httpHost = env('HTTP_HOST')) {
list($host) = explode(':', $httpHost);
} else {
$host = 'localhost';
}
try {
$this->_smtpSend("EHLO {$host}", '250');
if ($config['tls']) {
$this->_smtpSend('STARTTLS', '220');
$this->_socket->enableCrypto('tls');
$this->_smtpSend("EHLO {$host}", '250');
}
} catch (SocketException $e) {
if ($config['tls']) {
throw new SocketException('SMTP server did not accept the connection or trying to connect to non TLS SMTP server using TLS.', null, $e);
}
try {
$this->_smtpSend("HELO {$host}", '250');
} catch (SocketException $e2) {
throw new SocketException('SMTP server did not accept the connection.', null, $e2);
}
}
}
/**
* Send authentication
*
* @return void
* @throws \Cake\Network\Exception\SocketException
*/
protected function _auth()
{
if (!isset($this->_config['username'], $this->_config['password'])) {
return;
}
$username = $this->_config['username'];
$password = $this->_config['password'];
$replyCode = $this->_authPlain($username, $password);
if ($replyCode === '235') {
return;
}
$this->_authLogin($username, $password);
}
/**
* Authenticate using AUTH PLAIN mechanism.
*
* @param string $username Username.
* @param string $password Password.
* @return string|null Response code for the command.
*/
protected function _authPlain($username, $password)
{
return $this->_smtpSend(
sprintf(
'AUTH PLAIN %s',
base64_encode(chr(0) . $username . chr(0) . $password)
),
'235|504|534|535'
);
}
/**
* Authenticate using AUTH LOGIN mechanism.
*
* @param string $username Username.
* @param string $password Password.
* @return void
*/
protected function _authLogin($username, $password)
{
$replyCode = $this->_smtpSend('AUTH LOGIN', '334|500|502|504');
if ($replyCode === '334') {
try {
$this->_smtpSend(base64_encode($username), '334');
} catch (SocketException $e) {
throw new SocketException('SMTP server did not accept the username.', null, $e);
}
try {
$this->_smtpSend(base64_encode($password), '235');
} catch (SocketException $e) {
throw new SocketException('SMTP server did not accept the password.', null, $e);
}
} elseif ($replyCode === '504') {
throw new SocketException('SMTP authentication method not allowed, check if SMTP server requires TLS.');
} else {
throw new SocketException(
'AUTH command not recognized or not implemented, SMTP server may not require authentication.'
);
}
}
/**
* Prepares the `MAIL FROM` SMTP command.
*
* @param string $email The email address to send with the command.
* @return string
*/
protected function _prepareFromCmd($email)
{
return 'MAIL FROM:<' . $email . '>';
}
/**
* Prepares the `RCPT TO` SMTP command.
*
* @param string $email The email address to send with the command.
* @return string
*/
protected function _prepareRcptCmd($email)
{
return 'RCPT TO:<' . $email . '>';
}
/**
* Prepares the `from` email address.
*
* @param \Cake\Mailer\Email $email Email instance
* @return array
*/
protected function _prepareFromAddress($email)
{
$from = $email->getReturnPath();
if (empty($from)) {
$from = $email->getFrom();
}
return $from;
}
/**
* Prepares the recipient email addresses.
*
* @param \Cake\Mailer\Email $email Email instance
* @return array
*/
protected function _prepareRecipientAddresses($email)
{
$to = $email->getTo();
$cc = $email->getCc();
$bcc = $email->getBcc();
return array_merge(array_keys($to), array_keys($cc), array_keys($bcc));
}
/**
* Prepares the message headers.
*
* @param \Cake\Mailer\Email $email Email instance
* @return array
*/
protected function _prepareMessageHeaders($email)
{
return $email->getHeaders(['from', 'sender', 'replyTo', 'readReceipt', 'to', 'cc', 'subject', 'returnPath']);
}
/**
* Prepares the message body.
*
* @param \Cake\Mailer\Email $email Email instance
* @return string
*/
protected function _prepareMessage($email)
{
$lines = $email->message();
$messages = [];
foreach ($lines as $line) {
if (!empty($line) && ($line[0] === '.')) {
$messages[] = '.' . $line;
} else {
$messages[] = $line;
}
}
return implode("\r\n", $messages);
}
/**
* Send emails
*
* @return void
* @param \Cake\Mailer\Email $email Cake Email
* @throws \Cake\Network\Exception\SocketException
*/
protected function _sendRcpt($email)
{
$from = $this->_prepareFromAddress($email);
$this->_smtpSend($this->_prepareFromCmd(key($from)));
$emails = $this->_prepareRecipientAddresses($email);
foreach ($emails as $mail) {
$this->_smtpSend($this->_prepareRcptCmd($mail));
}
}
/**
* Send Data
*
* @param \Cake\Mailer\Email $email Email instance
* @return void
* @throws \Cake\Network\Exception\SocketException
*/
protected function _sendData($email)
{
$this->_smtpSend('DATA', '354');
$headers = $this->_headersToString($this->_prepareMessageHeaders($email));
$message = $this->_prepareMessage($email);
$this->_smtpSend($headers . "\r\n\r\n" . $message . "\r\n\r\n\r\n.");
$this->_content = ['headers' => $headers, 'message' => $message];
}
/**
* Disconnect
*
* @return void
* @throws \Cake\Network\Exception\SocketException
*/
protected function _disconnect()
{
$this->_smtpSend('QUIT', false);
$this->_socket->disconnect();
}
/**
* Helper method to generate socket
*
* @return void
* @throws \Cake\Network\Exception\SocketException
*/
protected function _generateSocket()
{
$this->_socket = new Socket($this->_config);
}
/**
* Protected method for sending data to SMTP connection
*
* @param string|null $data Data to be sent to SMTP server
* @param string|false $checkCode Code to check for in server response, false to skip
* @return string|null The matched code, or null if nothing matched
* @throws \Cake\Network\Exception\SocketException
*/
protected function _smtpSend($data, $checkCode = '250')
{
$this->_lastResponse = [];
if ($data !== null) {
$this->_socket->write($data . "\r\n");
}
$timeout = $this->_config['timeout'];
while ($checkCode !== false) {
$response = '';
$startTime = time();
while (substr($response, -2) !== "\r\n" && ((time() - $startTime) < $timeout)) {
$bytes = $this->_socket->read();
if ($bytes === false || $bytes === null) {
break;
}
$response .= $bytes;
}
if (substr($response, -2) !== "\r\n") {
throw new SocketException('SMTP timeout.');
}
$responseLines = explode("\r\n", rtrim($response, "\r\n"));
$response = end($responseLines);
$this->_bufferResponseLines($responseLines);
if (preg_match('/^(' . $checkCode . ')(.)/', $response, $code)) {
if ($code[2] === '-') {
continue;
}
return $code[1];
}
throw new SocketException(sprintf('SMTP Error: %s', $response));
}
}
}