weekly release 3.3dev
[moodle.git] / lib / oauthlib.php
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3e123368 1<?php
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2// This file is part of Moodle - http://moodle.org/
3//
4// Moodle is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8//
9// Moodle is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12// GNU General Public License for more details.
13//
14// You should have received a copy of the GNU General Public License
15// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
16
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17
18defined('MOODLE_INTERNAL') || die();
19
20require_once($CFG->libdir.'/filelib.php');
21
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22/**
23 * OAuth helper class
24 *
25 * 1. You can extends oauth_helper to add specific functions, such as twitter extends oauth_helper
26 * 2. Call request_token method to get oauth_token and oauth_token_secret, and redirect user to authorize_url,
27 * developer needs to store oauth_token and oauth_token_secret somewhere, we will use them to request
28 * access token later on
29 * 3. User approved the request, and get back to moodle
30 * 4. Call get_access_token, it takes previous oauth_token and oauth_token_secret as arguments, oauth_token
31 * will be used in OAuth request, oauth_token_secret will be used to bulid signature, this method will
32 * return access_token and access_secret, store these two values in database or session
33 * 5. Now you can access oauth protected resources by access_token and access_secret using oauth_helper::request
34 * method (or get() post())
35 *
36 * Note:
37 * 1. This class only support HMAC-SHA1
38 * 2. oauth_helper class don't store tokens and secrets, you must store them manually
39 * 3. Some functions are based on http://code.google.com/p/oauth/
40 *
41 * @package moodlecore
42 * @copyright 2010 Dongsheng Cai <dongsheng@moodle.com>
43 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
44 */
45
46class oauth_helper {
47 /** @var string consumer key, issued by oauth provider*/
48 protected $consumer_key;
49 /** @var string consumer secret, issued by oauth provider*/
50 protected $consumer_secret;
51 /** @var string oauth root*/
52 protected $api_root;
53 /** @var string request token url*/
54 protected $request_token_api;
55 /** @var string authorize url*/
56 protected $authorize_url;
57 protected $http_method;
58 /** @var string */
59 protected $access_token_api;
60 /** @var curl */
61 protected $http;
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62 /** @var array options to pass to the next curl request */
63 protected $http_options;
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64
65 /**
66 * Contructor for oauth_helper.
67 * Subclass can override construct to build its own $this->http
68 *
69 * @param array $args requires at least three keys, oauth_consumer_key
70 * oauth_consumer_secret and api_root, oauth_helper will
71 * guess request_token_api, authrize_url and access_token_api
72 * based on api_root, but it not always works
73 */
74 function __construct($args) {
75 if (!empty($args['api_root'])) {
76 $this->api_root = $args['api_root'];
77 } else {
78 $this->api_root = '';
79 }
80 $this->consumer_key = $args['oauth_consumer_key'];
81 $this->consumer_secret = $args['oauth_consumer_secret'];
82
83 if (empty($args['request_token_api'])) {
84 $this->request_token_api = $this->api_root . '/request_token';
85 } else {
86 $this->request_token_api = $args['request_token_api'];
87 }
88
89 if (empty($args['authorize_url'])) {
90 $this->authorize_url = $this->api_root . '/authorize';
91 } else {
92 $this->authorize_url = $args['authorize_url'];
93 }
94
95 if (empty($args['access_token_api'])) {
96 $this->access_token_api = $this->api_root . '/access_token';
97 } else {
98 $this->access_token_api = $args['access_token_api'];
99 }
100
101 if (!empty($args['oauth_callback'])) {
102 $this->oauth_callback = new moodle_url($args['oauth_callback']);
103 }
104 if (!empty($args['access_token'])) {
105 $this->access_token = $args['access_token'];
106 }
107 if (!empty($args['access_token_secret'])) {
108 $this->access_token_secret = $args['access_token_secret'];
109 }
110 $this->http = new curl(array('debug'=>false));
8d8a6009 111 $this->http_options = array();
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112 }
113
114 /**
115 * Build parameters list:
116 * oauth_consumer_key="0685bd9184jfhq22",
117 * oauth_nonce="4572616e48616d6d65724c61686176",
118 * oauth_token="ad180jjd733klru7",
119 * oauth_signature_method="HMAC-SHA1",
120 * oauth_signature="wOJIO9A2W5mFwDgiDvZbTSMK%2FPY%3D",
121 * oauth_timestamp="137131200",
122 * oauth_version="1.0"
123 * oauth_verifier="1.0"
124 * @param array $param
125 * @return string
126 */
127 function get_signable_parameters($params){
128 $sorted = $params;
129 ksort($sorted);
130
131 $total = array();
132 foreach ($sorted as $k => $v) {
133 if ($k == 'oauth_signature') {
134 continue;
135 }
136
137 $total[] = rawurlencode($k) . '=' . rawurlencode($v);
138 }
139 return implode('&', $total);
140 }
141
142 /**
143 * Create signature for oauth request
144 * @param string $url
145 * @param string $secret
146 * @param array $params
147 * @return string
148 */
149 public function sign($http_method, $url, $params, $secret) {
150 $sig = array(
151 strtoupper($http_method),
152 preg_replace('/%7E/', '~', rawurlencode($url)),
153 rawurlencode($this->get_signable_parameters($params)),
154 );
155
156 $base_string = implode('&', $sig);
157 $sig = base64_encode(hash_hmac('sha1', $base_string, $secret, true));
158 return $sig;
159 }
160
161 /**
162 * Initilize oauth request parameters, including:
163 * oauth_consumer_key="0685bd9184jfhq22",
164 * oauth_token="ad180jjd733klru7",
165 * oauth_signature_method="HMAC-SHA1",
166 * oauth_signature="wOJIO9A2W5mFwDgiDvZbTSMK%2FPY%3D",
167 * oauth_timestamp="137131200",
168 * oauth_nonce="4572616e48616d6d65724c61686176",
169 * oauth_version="1.0"
170 * To access protected resources, oauth_token should be defined
171 *
172 * @param string $url
173 * @param string $token
174 * @param string $http_method
175 * @return array
176 */
177 public function prepare_oauth_parameters($url, $params, $http_method = 'POST') {
178 if (is_array($params)) {
179 $oauth_params = $params;
180 } else {
181 $oauth_params = array();
182 }
183 $oauth_params['oauth_version'] = '1.0';
184 $oauth_params['oauth_nonce'] = $this->get_nonce();
185 $oauth_params['oauth_timestamp'] = $this->get_timestamp();
186 $oauth_params['oauth_consumer_key'] = $this->consumer_key;
187 if (!empty($this->oauth_callback)) {
188 $oauth_params['oauth_callback'] = $this->oauth_callback->out(false);
189 }
190 $oauth_params['oauth_signature_method'] = 'HMAC-SHA1';
191 $oauth_params['oauth_signature'] = $this->sign($http_method, $url, $oauth_params, $this->sign_secret);
192 return $oauth_params;
193 }
194
195 public function setup_oauth_http_header($params) {
196
197 $total = array();
198 ksort($params);
199 foreach ($params as $k => $v) {
200 $total[] = rawurlencode($k) . '="' . rawurlencode($v).'"';
201 }
202 $str = implode(', ', $total);
203 $str = 'Authorization: OAuth '.$str;
204 $this->http->setHeader('Expect:');
205 $this->http->setHeader($str);
206 }
207
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208 /**
209 * Sets the options for the next curl request
210 *
211 * @param array $options
212 */
213 public function setup_oauth_http_options($options) {
214 $this->http_options = $options;
215 }
216
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217 /**
218 * Request token for authentication
219 * This is the first step to use OAuth, it will return oauth_token and oauth_token_secret
220 * @return array
221 */
222 public function request_token() {
223 $this->sign_secret = $this->consumer_secret.'&';
224 $params = $this->prepare_oauth_parameters($this->request_token_api, array(), 'GET');
8d8a6009 225 $content = $this->http->get($this->request_token_api, $params, $this->http_options);
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226 // Including:
227 // oauth_token
228 // oauth_token_secret
229 $result = $this->parse_result($content);
230 if (empty($result['oauth_token'])) {
0e6ee5e9 231 throw new moodle_exception('Error while requesting an oauth token');
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232 }
233 // build oauth authrize url
234 if (!empty($this->oauth_callback)) {
235 // url must be rawurlencode
236 $result['authorize_url'] = $this->authorize_url . '?oauth_token='.$result['oauth_token'].'&oauth_callback='.rawurlencode($this->oauth_callback->out(false));
237 } else {
238 // no callback
239 $result['authorize_url'] = $this->authorize_url . '?oauth_token='.$result['oauth_token'];
240 }
241 return $result;
242 }
243
244 /**
245 * Set oauth access token for oauth request
246 * @param string $token
247 * @param string $secret
248 */
249 public function set_access_token($token, $secret) {
250 $this->access_token = $token;
251 $this->access_token_secret = $secret;
252 }
253
254 /**
255 * Request oauth access token from server
256 * @param string $method
257 * @param string $url
258 * @param string $token
259 * @param string $secret
260 */
261 public function get_access_token($token, $secret, $verifier='') {
262 $this->sign_secret = $this->consumer_secret.'&'.$secret;
263 $params = $this->prepare_oauth_parameters($this->access_token_api, array('oauth_token'=>$token, 'oauth_verifier'=>$verifier), 'POST');
264 $this->setup_oauth_http_header($params);
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265 // Should never send the callback in this request.
266 unset($params['oauth_callback']);
8d8a6009 267 $content = $this->http->post($this->access_token_api, $params, $this->http_options);
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268 $keys = $this->parse_result($content);
269 $this->set_access_token($keys['oauth_token'], $keys['oauth_token_secret']);
270 return $keys;
271 }
272
273 /**
274 * Request oauth protected resources
275 * @param string $method
276 * @param string $url
277 * @param string $token
278 * @param string $secret
279 */
280 public function request($method, $url, $params=array(), $token='', $secret='') {
281 if (empty($token)) {
282 $token = $this->access_token;
283 }
284 if (empty($secret)) {
285 $secret = $this->access_token_secret;
286 }
287 // to access protected resource, sign_secret will alwasy be consumer_secret+token_secret
288 $this->sign_secret = $this->consumer_secret.'&'.$secret;
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289 if (strtolower($method) === 'post' && !empty($params)) {
290 $oauth_params = $this->prepare_oauth_parameters($url, array('oauth_token'=>$token) + $params, $method);
291 } else {
292 $oauth_params = $this->prepare_oauth_parameters($url, array('oauth_token'=>$token), $method);
293 }
3e123368 294 $this->setup_oauth_http_header($oauth_params);
8d8a6009 295 $content = call_user_func_array(array($this->http, strtolower($method)), array($url, $params, $this->http_options));
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296 // reset http header and options to prepare for the next request
297 $this->http->resetHeader();
298 // return request return value
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299 return $content;
300 }
301
302 /**
303 * shortcut to start http get request
304 */
305 public function get($url, $params=array(), $token='', $secret='') {
306 return $this->request('GET', $url, $params, $token, $secret);
307 }
308
309 /**
310 * shortcut to start http post request
311 */
312 public function post($url, $params=array(), $token='', $secret='') {
313 return $this->request('POST', $url, $params, $token, $secret);
314 }
315
316 /**
317 * A method to parse oauth response to get oauth_token and oauth_token_secret
318 * @param string $str
319 * @return array
320 */
321 public function parse_result($str) {
322 if (empty($str)) {
323 throw new moodle_exception('error');
324 }
325 $parts = explode('&', $str);
326 $result = array();
327 foreach ($parts as $part){
328 list($k, $v) = explode('=', $part, 2);
329 $result[urldecode($k)] = urldecode($v);
330 }
331 if (empty($result)) {
332 throw new moodle_exception('error');
333 }
334 return $result;
335 }
336
337 /**
338 * Set nonce
339 */
340 function set_nonce($str) {
341 $this->nonce = $str;
342 }
343 /**
344 * Set timestamp
345 */
346 function set_timestamp($time) {
347 $this->timestamp = $time;
348 }
349 /**
350 * Generate timestamp
351 */
352 function get_timestamp() {
353 if (!empty($this->timestamp)) {
354 $timestamp = $this->timestamp;
355 unset($this->timestamp);
356 return $timestamp;
357 }
358 return time();
359 }
360 /**
361 * Generate nonce for oauth request
362 */
363 function get_nonce() {
364 if (!empty($this->nonce)) {
365 $nonce = $this->nonce;
366 unset($this->nonce);
367 return $nonce;
368 }
369 $mt = microtime();
370 $rand = mt_rand();
371
372 return md5($mt . $rand);
373 }
374}
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375
376/**
377 * OAuth 2.0 Client for using web access tokens.
378 *
379 * http://tools.ietf.org/html/draft-ietf-oauth-v2-22
380 *
381 * @package core
382 * @copyright Dan Poltawski <talktodan@gmail.com>
383 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
384 */
385abstract class oauth2_client extends curl {
386 /** var string client identifier issued to the client */
387 private $clientid = '';
388 /** var string The client secret. */
389 private $clientsecret = '';
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390 /** var moodle_url URL to return to after authenticating */
391 private $returnurl = null;
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392 /** var string scope of the authentication request */
393 private $scope = '';
394 /** var stdClass access token object */
395 private $accesstoken = null;
396
397 /**
398 * Returns the auth url for OAuth 2.0 request
399 * @return string the auth url
400 */
401 abstract protected function auth_url();
402
403 /**
404 * Returns the token url for OAuth 2.0 request
405 * @return string the auth url
406 */
407 abstract protected function token_url();
408
409 /**
410 * Constructor.
411 *
412 * @param string $clientid
413 * @param string $clientsecret
db7602af 414 * @param moodle_url $returnurl
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415 * @param string $scope
416 */
db7602af 417 public function __construct($clientid, $clientsecret, moodle_url $returnurl, $scope) {
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418 parent::__construct();
419 $this->clientid = $clientid;
420 $this->clientsecret = $clientsecret;
421 $this->returnurl = $returnurl;
422 $this->scope = $scope;
423 $this->accesstoken = $this->get_stored_token();
424 }
425
426 /**
427 * Is the user logged in? Note that if this is called
428 * after the first part of the authorisation flow the token
429 * is upgraded to an accesstoken.
430 *
431 * @return boolean true if logged in
432 */
433 public function is_logged_in() {
434 // Has the token expired?
435 if (isset($this->accesstoken->expires) && time() >= $this->accesstoken->expires) {
436 $this->log_out();
437 return false;
438 }
439
440 // We have a token so we are logged in.
441 if (isset($this->accesstoken->token)) {
442 return true;
443 }
444
445 // If we've been passed then authorization code generated by the
446 // authorization server try and upgrade the token to an access token.
7b61ac39 447 $code = optional_param('oauth2code', null, PARAM_RAW);
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448 if ($code && $this->upgrade_token($code)) {
449 return true;
450 }
451
452 return false;
453 }
454
455 /**
456 * Callback url where the request is returned to.
457 *
458 * @return moodle_url url of callback
459 */
460 public static function callback_url() {
461 global $CFG;
462
463 return new moodle_url('/admin/oauth2callback.php');
464 }
465
466 /**
467 * Returns the login link for this oauth request
468 *
469 * @return moodle_url login url
470 */
471 public function get_login_url() {
472
473 $callbackurl = self::callback_url();
474 $url = new moodle_url($this->auth_url(),
475 array('client_id' => $this->clientid,
476 'response_type' => 'code',
477 'redirect_uri' => $callbackurl->out(false),
db7602af 478 'state' => $this->returnurl->out_as_local_url(false),
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479 'scope' => $this->scope,
480 ));
481
482 return $url;
483 }
484
485 /**
486 * Upgrade a authorization token from oauth 2.0 to an access token
487 *
488 * @param string $code the code returned from the oauth authenticaiton
489 * @return boolean true if token is upgraded succesfully
490 */
491 public function upgrade_token($code) {
492 $callbackurl = self::callback_url();
493 $params = array('client_id' => $this->clientid,
494 'client_secret' => $this->clientsecret,
495 'grant_type' => 'authorization_code',
496 'code' => $code,
497 'redirect_uri' => $callbackurl->out(false),
498 );
499
500 // Requests can either use http GET or POST.
501 if ($this->use_http_get()) {
502 $response = $this->get($this->token_url(), $params);
503 } else {
504 $response = $this->post($this->token_url(), $params);
505 }
506
507 if (!$this->info['http_code'] === 200) {
508 throw new moodle_exception('Could not upgrade oauth token');
509 }
510
511 $r = json_decode($response);
512
513 if (!isset($r->access_token)) {
514 return false;
515 }
516
517 // Store the token an expiry time.
518 $accesstoken = new stdClass;
519 $accesstoken->token = $r->access_token;
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520 if (isset($r->expires_in)) {
521 // Expires 10 seconds before actual expiry.
522 $accesstoken->expires = (time() + ($r->expires_in - 10));
523 }
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524 $this->store_token($accesstoken);
525
526 return true;
527 }
528
529 /**
530 * Logs out of a oauth request, clearing any stored tokens
531 */
532 public function log_out() {
533 $this->store_token(null);
534 }
535
536 /**
537 * Make a HTTP request, adding the access token we have
538 *
539 * @param string $url The URL to request
540 * @param array $options
541 * @return bool
542 */
543 protected function request($url, $options = array()) {
544 $murl = new moodle_url($url);
545
546 if ($this->accesstoken) {
547 if ($this->use_http_get()) {
548 // If using HTTP GET add as a parameter.
549 $murl->param('access_token', $this->accesstoken->token);
550 } else {
551 $this->setHeader('Authorization: Bearer '.$this->accesstoken->token);
552 }
553 }
554
555 return parent::request($murl->out(false), $options);
556 }
557
558 /**
559 * Multiple HTTP Requests
560 * This function could run multi-requests in parallel.
561 *
562 * @param array $requests An array of files to request
563 * @param array $options An array of options to set
564 * @return array An array of results
565 */
566 protected function multi($requests, $options = array()) {
567 if ($this->accesstoken) {
568 $this->setHeader('Authorization: Bearer '.$this->accesstoken->token);
569 }
570 return parent::multi($requests, $options);
571 }
572
573 /**
574 * Returns the tokenname for the access_token to be stored
575 * through multiple requests.
576 *
577 * The default implentation is to use the classname combiend
578 * with the scope.
579 *
580 * @return string tokenname for prefernce storage
581 */
582 protected function get_tokenname() {
583 // This is unusual but should work for most purposes.
584 return get_class($this).'-'.md5($this->scope);
585 }
586
587 /**
588 * Store a token between requests. Currently uses
589 * session named by get_tokenname
590 *
591 * @param stdClass|null $token token object to store or null to clear
592 */
593 protected function store_token($token) {
594 global $SESSION;
595
596 $this->accesstoken = $token;
597 $name = $this->get_tokenname();
598
599 if ($token !== null) {
600 $SESSION->{$name} = $token;
601 } else {
602 unset($SESSION->{$name});
603 }
604 }
605
606 /**
607 * Retrieve a token stored.
608 *
609 * @return stdClass|null token object
610 */
611 protected function get_stored_token() {
612 global $SESSION;
613
614 $name = $this->get_tokenname();
615
616 if (isset($SESSION->{$name})) {
617 return $SESSION->{$name};
618 }
619
620 return null;
621 }
622
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623 /**
624 * Get access token.
625 *
626 * This is just a getter to read the private property.
627 *
628 * @return string
629 */
630 public function get_accesstoken() {
631 return $this->accesstoken;
632 }
633
634 /**
635 * Get the client ID.
636 *
637 * This is just a getter to read the private property.
638 *
639 * @return string
640 */
641 public function get_clientid() {
642 return $this->clientid;
643 }
644
645 /**
646 * Get the client secret.
647 *
648 * This is just a getter to read the private property.
649 *
650 * @return string
651 */
652 public function get_clientsecret() {
653 return $this->clientsecret;
654 }
655
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656 /**
657 * Should HTTP GET be used instead of POST?
658 * Some APIs do not support POST and want oauth to use
659 * GET instead (with the auth_token passed as a GET param).
660 *
661 * @return bool true if GET should be used
662 */
663 protected function use_http_get() {
664 return false;
665 }
666}