1<?php
2
3/**
4 * PHPMailer POP-Before-SMTP Authentication Class.
5 * PHP Version 5.5.
6 *
7 * @see https://github.com/PHPMailer/PHPMailer/ The PHPMailer GitHub project
8 *
9 * @author Marcus Bointon (Synchro/coolbru) <phpmailer@synchromedia.co.uk>
10 * @author Jim Jagielski (jimjag) <jimjag@gmail.com>
11 * @author Andy Prevost (codeworxtech) <codeworxtech@users.sourceforge.net>
12 * @author Brent R. Matzelle (original founder)
13 * @copyright 2012 - 2020 Marcus Bointon
14 * @copyright 2010 - 2012 Jim Jagielski
15 * @copyright 2004 - 2009 Andy Prevost
16 * @license https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html GNU Lesser General Public License
17 * @note This program is distributed in the hope that it will be useful - WITHOUT
18 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
19 * FITNESS FOR A PARTICULAR PURPOSE.
20 */
21
22namespace PHPMailer\PHPMailer;
23
24/**
25 * PHPMailer POP-Before-SMTP Authentication Class.
26 * Specifically for PHPMailer to use for RFC1939 POP-before-SMTP authentication.
27 * 1) This class does not support APOP authentication.
28 * 2) Opening and closing lots of POP3 connections can be quite slow. If you need
29 * to send a batch of emails then just perform the authentication once at the start,
30 * and then loop through your mail sending script. Providing this process doesn't
31 * take longer than the verification period lasts on your POP3 server, you should be fine.
32 * 3) This is really ancient technology; you should only need to use it to talk to very old systems.
33 * 4) This POP3 class is deliberately lightweight and incomplete, implementing just
34 * enough to do authentication.
35 * If you want a more complete class there are other POP3 classes for PHP available.
36 *
37 * @author Richard Davey (original author) <rich@corephp.co.uk>
38 * @author Marcus Bointon (Synchro/coolbru) <phpmailer@synchromedia.co.uk>
39 * @author Jim Jagielski (jimjag) <jimjag@gmail.com>
40 * @author Andy Prevost (codeworxtech) <codeworxtech@users.sourceforge.net>
41 */
42class POP3
43{
44 /**
45 * The POP3 PHPMailer Version number.
46 *
47 * @var string
48 */
49 const VERSION = '7.0.0';
50
51 /**
52 * Default POP3 port number.
53 *
54 * @var int
55 */
56 const DEFAULT_PORT = 110;
57
58 /**
59 * Default timeout in seconds.
60 *
61 * @var int
62 */
63 const DEFAULT_TIMEOUT = 30;
64
65 /**
66 * POP3 class debug output mode.
67 * Debug output level.
68 * Options:
69 * @see POP3::DEBUG_OFF: No output
70 * @see POP3::DEBUG_SERVER: Server messages, connection/server errors
71 * @see POP3::DEBUG_CLIENT: Client and Server messages, connection/server errors
72 *
73 * @var int
74 */
75 public $do_debug = self::DEBUG_OFF;
76
77 /**
78 * POP3 mail server hostname.
79 *
80 * @var string
81 */
82 public $host;
83
84 /**
85 * POP3 port number.
86 *
87 * @var int
88 */
89 public $port;
90
91 /**
92 * POP3 Timeout Value in seconds.
93 *
94 * @var int
95 */
96 public $tval;
97
98 /**
99 * POP3 username.
100 *
101 * @var string
102 */
103 public $username;
104
105 /**
106 * POP3 password.
107 *
108 * @var string
109 */
110 public $password;
111
112 /**
113 * Resource handle for the POP3 connection socket.
114 *
115 * @var resource
116 */
117 protected $pop_conn;
118
119 /**
120 * Are we connected?
121 *
122 * @var bool
123 */
124 protected $connected = false;
125
126 /**
127 * Error container.
128 *
129 * @var array
130 */
131 protected $errors = [];
132
133 /**
134 * Line break constant.
135 */
136 const LE = "\r\n";
137
138 /**
139 * Debug level for no output.
140 *
141 * @var int
142 */
143 const DEBUG_OFF = 0;
144
145 /**
146 * Debug level to show server -> client messages
147 * also shows clients connection errors or errors from server
148 *
149 * @var int
150 */
151 const DEBUG_SERVER = 1;
152
153 /**
154 * Debug level to show client -> server and server -> client messages.
155 *
156 * @var int
157 */
158 const DEBUG_CLIENT = 2;
159
160 /**
161 * Simple static wrapper for all-in-one POP before SMTP.
162 *
163 * @param string $host The hostname to connect to
164 * @param int|bool $port The port number to connect to
165 * @param int|bool $timeout The timeout value
166 * @param string $username
167 * @param string $password
168 * @param int $debug_level
169 *
170 * @return bool
171 */
172 public static function popBeforeSmtp(
173 $host,
174 $port = false,
175 $timeout = false,
176 $username = '',
177 $password = '',
178 $debug_level = 0
179 ) {
180 $pop = new self();
181
182 return $pop->authorise($host, $port, $timeout, $username, $password, $debug_level);
183 }
184
185 /**
186 * Authenticate with a POP3 server.
187 * A connect, login, disconnect sequence
188 * appropriate for POP-before SMTP authorisation.
189 *
190 * @param string $host The hostname to connect to
191 * @param int|bool $port The port number to connect to
192 * @param int|bool $timeout The timeout value
193 * @param string $username
194 * @param string $password
195 * @param int $debug_level
196 *
197 * @return bool
198 */
199 public function authorise($host, $port = false, $timeout = false, $username = '', $password = '', $debug_level = 0)
200 {
201 $this->host = $host;
202 //If no port value provided, use default
203 if (false === $port) {
204 $this->port = static::DEFAULT_PORT;
205 } else {
206 $this->port = (int) $port;
207 }
208 //If no timeout value provided, use default
209 if (false === $timeout) {
210 $this->tval = static::DEFAULT_TIMEOUT;
211 } else {
212 $this->tval = (int) $timeout;
213 }
214 $this->do_debug = $debug_level;
215 $this->username = $username;
216 $this->password = $password;
217 //Reset the error log
218 $this->errors = [];
219 //Connect
220 $result = $this->connect($this->host, $this->port, $this->tval);
221 if ($result) {
222 $login_result = $this->login($this->username, $this->password);
223 if ($login_result) {
224 $this->disconnect();
225
226 return true;
227 }
228 }
229 //We need to disconnect regardless of whether the login succeeded
230 $this->disconnect();
231
232 return false;
233 }
234
235 /**
236 * Connect to a POP3 server.
237 *
238 * @param string $host
239 * @param int|bool $port
240 * @param int $tval
241 *
242 * @return bool
243 */
244 public function connect($host, $port = false, $tval = 30)
245 {
246 //Are we already connected?
247 if ($this->connected) {
248 return true;
249 }
250
251 //On Windows this will raise a PHP Warning error if the hostname doesn't exist.
252 //Rather than suppress it with @fsockopen, capture it cleanly instead
253 set_error_handler(function () {
254 call_user_func_array([$this, 'catchWarning'], func_get_args());
255 });
256
257 if (false === $port) {
258 $port = static::DEFAULT_PORT;
259 }
260
261 //Connect to the POP3 server
262 $errno = 0;
263 $errstr = '';
264 $this->pop_conn = fsockopen(
265 $host, //POP3 Host
266 $port, //Port #
267 $errno, //Error Number
268 $errstr, //Error Message
269 $tval
270 ); //Timeout (seconds)
271 //Restore the error handler
272 restore_error_handler();
273
274 //Did we connect?
275 if (false === $this->pop_conn) {
276 //It would appear not...
277 $this->setError(
278 "Failed to connect to server $host on port $port. errno: $errno; errstr: $errstr"
279 );
280
281 return false;
282 }
283
284 //Increase the stream time-out
285 stream_set_timeout($this->pop_conn, $tval, 0);
286
287 //Get the POP3 server response
288 $pop3_response = $this->getResponse();
289 //Check for the +OK
290 if ($this->checkResponse($pop3_response)) {
291 //The connection is established and the POP3 server is talking
292 $this->connected = true;
293
294 return true;
295 }
296
297 return false;
298 }
299
300 /**
301 * Log in to the POP3 server.
302 * Does not support APOP (RFC 2828, 4949).
303 *
304 * @param string $username
305 * @param string $password
306 *
307 * @return bool
308 */
309 public function login($username = '', $password = '')
310 {
311 if (!$this->connected) {
312 $this->setError('Not connected to POP3 server');
313 return false;
314 }
315 if (empty($username)) {
316 $username = $this->username;
317 }
318 if (empty($password)) {
319 $password = $this->password;
320 }
321
322 //Send the Username
323 $this->sendString("USER $username" . static::LE);
324 $pop3_response = $this->getResponse();
325 if ($this->checkResponse($pop3_response)) {
326 //Send the Password
327 $this->sendString("PASS $password" . static::LE);
328 $pop3_response = $this->getResponse();
329 if ($this->checkResponse($pop3_response)) {
330 return true;
331 }
332 }
333
334 return false;
335 }
336
337 /**
338 * Disconnect from the POP3 server.
339 */
340 public function disconnect()
341 {
342 // If could not connect at all, no need to disconnect
343 if ($this->pop_conn === false) {
344 return;
345 }
346
347 $this->sendString('QUIT' . static::LE);
348
349 // RFC 1939 shows POP3 server sending a +OK response to the QUIT command.
350 // Try to get it. Ignore any failures here.
351 try {
352 $this->getResponse();
353 } catch (Exception $e) {
354 //Do nothing
355 }
356
357 //The QUIT command may cause the daemon to exit, which will kill our connection
358 //So ignore errors here
359 try {
360 @fclose($this->pop_conn);
361 } catch (Exception $e) {
362 //Do nothing
363 }
364
365 // Clean up attributes.
366 $this->connected = false;
367 $this->pop_conn = false;
368 }
369
370 /**
371 * Get a response from the POP3 server.
372 *
373 * @param int $size The maximum number of bytes to retrieve
374 *
375 * @return string
376 */
377 protected function getResponse($size = 128)
378 {
379 $response = fgets($this->pop_conn, $size);
380 if ($this->do_debug >= self::DEBUG_SERVER) {
381 echo 'Server -> Client: ', $response;
382 }
383
384 return $response;
385 }
386
387 /**
388 * Send raw data to the POP3 server.
389 *
390 * @param string $string
391 *
392 * @return int
393 */
394 protected function sendString($string)
395 {
396 if ($this->pop_conn) {
397 if ($this->do_debug >= self::DEBUG_CLIENT) { //Show client messages when debug >= 2
398 echo 'Client -> Server: ', $string;
399 }
400
401 return fwrite($this->pop_conn, $string, strlen($string));
402 }
403
404 return 0;
405 }
406
407 /**
408 * Checks the POP3 server response.
409 * Looks for for +OK or -ERR.
410 *
411 * @param string $string
412 *
413 * @return bool
414 */
415 protected function checkResponse($string)
416 {
417 if (strpos($string, '+OK') !== 0) {
418 $this->setError("Server reported an error: $string");
419
420 return false;
421 }
422
423 return true;
424 }
425
426 /**
427 * Add an error to the internal error store.
428 * Also display debug output if it's enabled.
429 *
430 * @param string $error
431 */
432 protected function setError($error)
433 {
434 $this->errors[] = $error;
435 if ($this->do_debug >= self::DEBUG_SERVER) {
436 echo '<pre>';
437 foreach ($this->errors as $e) {
438 print_r($e);
439 }
440 echo '</pre>';
441 }
442 }
443
444 /**
445 * Get an array of error messages, if any.
446 *
447 * @return array
448 */
449 public function getErrors()
450 {
451 return $this->errors;
452 }
453
454 /**
455 * POP3 connection error handler.
456 *
457 * @param int $errno
458 * @param string $errstr
459 * @param string $errfile
460 * @param int $errline
461 */
462 protected function catchWarning($errno, $errstr, $errfile, $errline)
463 {
464 $this->setError(
465 'Connecting to the POP3 server raised a PHP warning:' .
466 "errno: $errno errstr: $errstr; errfile: $errfile; errline: $errline"
467 );
468 }
469}
470