Search moodle.org's
Developer Documentation
Developer Documentation
- Bug fixes for general core bugs in 4.2.x will end 22 April 2024 (12 months).
- Bug fixes for security issues in 4.2.x will end 7 October 2024 (18 months).
- PHP version: minimum PHP 8.0.0 Note: minimum PHP version has increased since Moodle 4.1. PHP 8.1.x is supported too.
Differences Between: [Versions 310 and 402] [Versions 311 and 402] [Versions 39 and 402] [Versions 400 and 402] [Versions 401 and 402]
1 <?php 2 // This file is part of BasicLTI4Moodle 3 // 4 // BasicLTI4Moodle is an IMS BasicLTI (Basic Learning Tools for Interoperability) 5 // consumer for Moodle 1.9 and Moodle 2.0. BasicLTI is a IMS Standard that allows web 6 // based learning tools to be easily integrated in LMS as native ones. The IMS BasicLTI 7 // specification is part of the IMS standard Common Cartridge 1.1 Sakai and other main LMS 8 // are already supporting or going to support BasicLTI. This project Implements the consumer 9 // for Moodle. Moodle is a Free Open source Learning Management System by Martin Dougiamas. 10 // BasicLTI4Moodle is a project iniciated and leaded by Ludo(Marc Alier) and Jordi Piguillem 11 // at the GESSI research group at UPC. 12 // SimpleLTI consumer for Moodle is an implementation of the early specification of LTI 13 // by Charles Severance (Dr Chuck) htp://dr-chuck.com , developed by Jordi Piguillem in a 14 // Google Summer of Code 2008 project co-mentored by Charles Severance and Marc Alier. 15 // 16 // BasicLTI4Moodle is copyright 2009 by Marc Alier Forment, Jordi Piguillem and Nikolas Galanis 17 // of the Universitat Politecnica de Catalunya http://www.upc.edu 18 // Contact info: Marc Alier Forment granludo @ gmail.com or marc.alier @ upc.edu 19 // 20 // OAuth.php is distributed under the MIT License 21 // 22 // The MIT License 23 // 24 // Copyright (c) 2007 Andy Smith 25 // 26 // Permission is hereby granted, free of charge, to any person obtaining a copy 27 // of this software and associated documentation files (the "Software"), to deal 28 // in the Software without restriction, including without limitation the rights 29 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 30 // copies of the Software, and to permit persons to whom the Software is 31 // furnished to do so, subject to the following conditions: 32 // 33 // The above copyright notice and this permission notice shall be included in 34 // all copies or substantial portions of the Software. 35 // 36 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 37 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 38 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 39 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 40 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 41 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 42 // THE SOFTWARE. 43 // 44 // Moodle is free software: you can redistribute it and/or modify 45 // it under the terms of the GNU General Public License as published by 46 // the Free Software Foundation, either version 3 of the License, or 47 // (at your option) any later version. 48 // 49 // Moodle is distributed in the hope that it will be useful, 50 // but WITHOUT ANY WARRANTY; without even the implied warranty of 51 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 52 // GNU General Public License for more details. 53 // 54 // You should have received a copy of the GNU General Public License 55 // along with Moodle. If not, see <http://www.gnu.org/licenses/>. 56 57 /** 58 * This file contains the OAuth 1.0a implementation used for support for LTI 1.1. 59 * 60 * @package mod_lti 61 * @copyright moodle 62 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later 63 */ 64 namespace moodle\mod\lti;//Using a namespace as the basicLTI module imports classes with the same names 65 66 defined('MOODLE_INTERNAL') || die; 67 68 $lastcomputedsignature = false; 69 70 /** 71 * Generic exception class 72 */ 73 class OAuthException extends \Exception { 74 // pass 75 } 76 77 /** 78 * OAuth 1.0 Consumer class 79 */ 80 class OAuthConsumer { 81 public $key; 82 public $secret; 83 84 /** @var string|null callback URL. */ 85 public ?string $callback_url; 86 87 function __construct($key, $secret, $callback_url = null) { 88 $this->key = $key; 89 $this->secret = $secret; 90 $this->callback_url = $callback_url; 91 } 92 93 function __toString() { 94 return "OAuthConsumer[key=$this->key,secret=$this->secret]"; 95 } 96 } 97 98 class OAuthToken { 99 // access tokens and request tokens 100 public $key; 101 public $secret; 102 103 /** 104 * key = the token 105 * secret = the token secret 106 */ 107 function __construct($key, $secret) { 108 $this->key = $key; 109 $this->secret = $secret; 110 } 111 112 /** 113 * generates the basic string serialization of a token that a server 114 * would respond to request_token and access_token calls with 115 */ 116 function to_string() { 117 return "oauth_token=" . 118 OAuthUtil::urlencode_rfc3986($this->key) . 119 "&oauth_token_secret=" . 120 OAuthUtil::urlencode_rfc3986($this->secret); 121 } 122 123 function __toString() { 124 return $this->to_string(); 125 } 126 } 127 128 class OAuthSignatureMethod { 129 public function check_signature(&$request, $consumer, $token, $signature) { 130 $built = $this->build_signature($request, $consumer, $token); 131 return $built == $signature; 132 } 133 } 134 135 136 /** 137 * Base class for the HMac based signature methods. 138 */ 139 abstract class OAuthSignatureMethod_HMAC extends OAuthSignatureMethod { 140 141 /** 142 * Name of the Algorithm used. 143 * 144 * @return string algorithm name. 145 */ 146 abstract public function get_name(): string; 147 148 public function build_signature($request, $consumer, $token) { 149 global $lastcomputedsignature; 150 $lastcomputedsignature = false; 151 152 $basestring = $request->get_signature_base_string(); 153 $request->base_string = $basestring; 154 155 $key_parts = array( 156 $consumer->secret, 157 ($token) ? $token->secret : "" 158 ); 159 160 $key_parts = OAuthUtil::urlencode_rfc3986($key_parts); 161 $key = implode('&', $key_parts); 162 163 $computedsignature = base64_encode(hash_hmac(strtolower(substr($this->get_name(), 5)), $basestring, $key, true)); 164 $lastcomputedsignature = $computedsignature; 165 return $computedsignature; 166 } 167 168 } 169 170 /** 171 * Implementation for SHA 1. 172 */ 173 class OAuthSignatureMethod_HMAC_SHA1 extends OAuthSignatureMethod_HMAC { 174 /** 175 * Name of the Algorithm used. 176 * 177 * @return string algorithm name. 178 */ 179 public function get_name(): string { 180 return "HMAC-SHA1"; 181 } 182 } 183 184 /** 185 * Implementation for SHA 256. 186 */ 187 class OAuthSignatureMethod_HMAC_SHA256 extends OAuthSignatureMethod_HMAC { 188 /** 189 * Name of the Algorithm used. 190 * 191 * @return string algorithm name. 192 */ 193 public function get_name(): string { 194 return "HMAC-SHA256"; 195 } 196 } 197 198 class OAuthSignatureMethod_PLAINTEXT extends OAuthSignatureMethod { 199 /** 200 * Name of the Algorithm used. 201 * 202 * @return string algorithm name. 203 */ 204 public function get_name(): string { 205 return "PLAINTEXT"; 206 } 207 208 public function build_signature($request, $consumer, $token) { 209 $sig = array( 210 OAuthUtil::urlencode_rfc3986($consumer->secret) 211 ); 212 213 if ($token) { 214 array_push($sig, OAuthUtil::urlencode_rfc3986($token->secret)); 215 } else { 216 array_push($sig, ''); 217 } 218 219 $raw = implode("&", $sig); 220 // for debug purposes 221 $request->base_string = $raw; 222 223 return OAuthUtil::urlencode_rfc3986($raw); 224 } 225 } 226 227 class OAuthSignatureMethod_RSA_SHA1 extends OAuthSignatureMethod { 228 /** 229 * Name of the Algorithm used. 230 * 231 * @return string algorithm name. 232 */ 233 public function get_name(): string { 234 return "RSA-SHA1"; 235 } 236 237 protected function fetch_public_cert(&$request) { 238 // not implemented yet, ideas are: 239 // (1) do a lookup in a table of trusted certs keyed off of consumer 240 // (2) fetch via http using a url provided by the requester 241 // (3) some sort of specific discovery code based on request 242 // 243 // either way should return a string representation of the certificate 244 throw new OAuthException("fetch_public_cert not implemented"); 245 } 246 247 protected function fetch_private_cert(&$request) { 248 // not implemented yet, ideas are: 249 // (1) do a lookup in a table of trusted certs keyed off of consumer 250 // 251 // either way should return a string representation of the certificate 252 throw new OAuthException("fetch_private_cert not implemented"); 253 } 254 255 public function build_signature(&$request, $consumer, $token) { 256 $base_string = $request->get_signature_base_string(); 257 $request->base_string = $base_string; 258 259 // Fetch the private key cert based on the request 260 $cert = $this->fetch_private_cert($request); 261 262 // Pull the private key ID from the certificate 263 $privatekeyid = openssl_get_privatekey($cert); 264 265 // Sign using the key 266 $ok = openssl_sign($base_string, $signature, $privatekeyid); 267 268 // Avoid passing null values to base64_encode. 269 if (!$ok) { 270 throw new OAuthException("OpenSSL unable to sign data"); 271 } 272 273 // TODO: Remove this block once PHP 8.0 becomes required. 274 if (PHP_MAJOR_VERSION < 8) { 275 // Release the key resource 276 openssl_free_key($privatekeyid); 277 } 278 279 return base64_encode($signature); 280 } 281 282 public function check_signature(&$request, $consumer, $token, $signature) { 283 $decoded_sig = base64_decode($signature); 284 285 $base_string = $request->get_signature_base_string(); 286 287 // Fetch the public key cert based on the request 288 $cert = $this->fetch_public_cert($request); 289 290 // Pull the public key ID from the certificate 291 $publickeyid = openssl_get_publickey($cert); 292 293 // Check the computed signature against the one passed in the query 294 $ok = openssl_verify($base_string, $decoded_sig, $publickeyid); 295 296 // TODO: Remove this block once PHP 8.0 becomes required. 297 if (PHP_MAJOR_VERSION < 8) { 298 // Release the key resource 299 openssl_free_key($publickeyid); 300 } 301 302 return $ok == 1; 303 } 304 } 305 306 class OAuthRequest { 307 private $parameters; 308 private $http_method; 309 private $http_url; 310 // for debug purposes 311 public $base_string; 312 public static $version = '1.0'; 313 public static $POST_INPUT = 'php://input'; 314 315 function __construct($http_method, $http_url, $parameters = null) { 316 @$parameters or $parameters = array(); 317 $this->parameters = $parameters; 318 $this->http_method = $http_method; 319 $this->http_url = $http_url; 320 } 321 322 /** 323 * attempt to build up a request from what was passed to the server 324 */ 325 public static function from_request($http_method = null, $http_url = null, $parameters = null) { 326 $scheme = (!is_https()) ? 'http' : 'https'; 327 $port = ""; 328 if ($_SERVER['SERVER_PORT'] != "80" && $_SERVER['SERVER_PORT'] != "443" && strpos(':', $_SERVER['HTTP_HOST']) < 0) { 329 $port = ':' . $_SERVER['SERVER_PORT']; 330 } 331 @$http_url or $http_url = $scheme . 332 '://' . $_SERVER['HTTP_HOST'] . 333 $port . 334 $_SERVER['REQUEST_URI']; 335 @$http_method or $http_method = $_SERVER['REQUEST_METHOD']; 336 337 // We weren't handed any parameters, so let's find the ones relevant to 338 // this request. 339 // If you run XML-RPC or similar you should use this to provide your own 340 // parsed parameter-list 341 if (!$parameters) { 342 // Find request headers 343 $request_headers = OAuthUtil::get_headers(); 344 345 // Parse the query-string to find GET parameters 346 $parameters = OAuthUtil::parse_parameters($_SERVER['QUERY_STRING']); 347 348 $ourpost = $_POST; 349 // Add POST Parameters if they exist 350 $parameters = array_merge($parameters, $ourpost); 351 352 // We have a Authorization-header with OAuth data. Parse the header 353 // and add those overriding any duplicates from GET or POST 354 if (@substr($request_headers['Authorization'], 0, 6) == "OAuth ") { 355 $header_parameters = OAuthUtil::split_header($request_headers['Authorization']); 356 $parameters = array_merge($parameters, $header_parameters); 357 } 358 359 } 360 361 return new OAuthRequest($http_method, $http_url, $parameters); 362 } 363 364 /** 365 * pretty much a helper function to set up the request 366 */ 367 public static function from_consumer_and_token($consumer, $token, $http_method, $http_url, $parameters = null) { 368 @$parameters or $parameters = array(); 369 $defaults = array( 370 "oauth_version" => self::$version, 371 "oauth_nonce" => self::generate_nonce(), 372 "oauth_timestamp" => self::generate_timestamp(), 373 "oauth_consumer_key" => $consumer->key 374 ); 375 if ($token) { 376 $defaults['oauth_token'] = $token->key; 377 } 378 379 $parameters = array_merge($defaults, $parameters); 380 381 // Parse the query-string to find and add GET parameters 382 $parts = parse_url($http_url); 383 if (isset($parts['query'])) { 384 $qparms = OAuthUtil::parse_parameters($parts['query']); 385 $parameters = array_merge($qparms, $parameters); 386 } 387 388 return new OAuthRequest($http_method, $http_url, $parameters); 389 } 390 391 public function set_parameter($name, $value, $allow_duplicates = true) { 392 if ($allow_duplicates && isset($this->parameters[$name])) { 393 // We have already added parameter(s) with this name, so add to the list 394 if (is_scalar($this->parameters[$name])) { 395 // This is the first duplicate, so transform scalar (string) 396 // into an array so we can add the duplicates 397 $this->parameters[$name] = array($this->parameters[$name]); 398 } 399 400 $this->parameters[$name][] = $value; 401 } else { 402 $this->parameters[$name] = $value; 403 } 404 } 405 406 public function get_parameter($name) { 407 return isset($this->parameters[$name]) ? $this->parameters[$name] : null; 408 } 409 410 public function get_parameters() { 411 return $this->parameters; 412 } 413 414 public function unset_parameter($name) { 415 unset($this->parameters[$name]); 416 } 417 418 /** 419 * The request parameters, sorted and concatenated into a normalized string. 420 * @return string 421 */ 422 public function get_signable_parameters() { 423 // Grab all parameters 424 $params = $this->parameters; 425 426 // Remove oauth_signature if present 427 // Ref: Spec: 9.1.1 ("The oauth_signature parameter MUST be excluded.") 428 if (isset($params['oauth_signature'])) { 429 unset($params['oauth_signature']); 430 } 431 432 return OAuthUtil::build_http_query($params); 433 } 434 435 /** 436 * Returns the base string of this request 437 * 438 * The base string defined as the method, the url 439 * and the parameters (normalized), each urlencoded 440 * and the concated with &. 441 */ 442 public function get_signature_base_string() { 443 $parts = array( 444 $this->get_normalized_http_method(), 445 $this->get_normalized_http_url(), 446 $this->get_signable_parameters() 447 ); 448 449 $parts = OAuthUtil::urlencode_rfc3986($parts); 450 451 return implode('&', $parts); 452 } 453 454 /** 455 * just uppercases the http method 456 */ 457 public function get_normalized_http_method() { 458 return strtoupper($this->http_method); 459 } 460 461 /** 462 * Parses {@see http_url} and returns normalized scheme://host/path if non-empty, otherwise return empty string 463 * 464 * @return string 465 */ 466 public function get_normalized_http_url() { 467 if ($this->http_url === '') { 468 return ''; 469 } 470 471 $parts = parse_url($this->http_url); 472 473 $port = @$parts['port']; 474 $scheme = $parts['scheme']; 475 $host = $parts['host']; 476 $path = @$parts['path']; 477 478 $port or $port = ($scheme == 'https') ? '443' : '80'; 479 480 if (($scheme == 'https' && $port != '443') || ($scheme == 'http' && $port != '80')) { 481 $host = "$host:$port"; 482 } 483 return "$scheme://$host$path"; 484 } 485 486 /** 487 * builds a url usable for a GET request 488 */ 489 public function to_url() { 490 $post_data = $this->to_postdata(); 491 $out = $this->get_normalized_http_url(); 492 if ($post_data) { 493 $out .= '?'.$post_data; 494 } 495 return $out; 496 } 497 498 /** 499 * builds the data one would send in a POST request 500 */ 501 public function to_postdata() { 502 return OAuthUtil::build_http_query($this->parameters); 503 } 504 505 /** 506 * builds the Authorization: header 507 */ 508 public function to_header() { 509 $out = 'Authorization: OAuth realm=""'; 510 $total = array(); 511 foreach ($this->parameters as $k => $v) { 512 if (substr($k, 0, 5) != "oauth") { 513 continue; 514 } 515 if (is_array($v)) { 516 throw new OAuthException('Arrays not supported in headers'); 517 } 518 $out .= ',' . 519 OAuthUtil::urlencode_rfc3986($k) . 520 '="' . 521 OAuthUtil::urlencode_rfc3986($v) . 522 '"'; 523 } 524 return $out; 525 } 526 527 public function __toString() { 528 return $this->to_url(); 529 } 530 531 public function sign_request($signature_method, $consumer, $token) { 532 $this->set_parameter("oauth_signature_method", $signature_method->get_name(), false); 533 $signature = $this->build_signature($signature_method, $consumer, $token); 534 $this->set_parameter("oauth_signature", $signature, false); 535 } 536 537 public function build_signature($signature_method, $consumer, $token) { 538 $signature = $signature_method->build_signature($this, $consumer, $token); 539 return $signature; 540 } 541 542 /** 543 * util function: current timestamp 544 */ 545 private static function generate_timestamp() { 546 return time(); 547 } 548 549 /** 550 * util function: current nonce 551 */ 552 private static function generate_nonce() { 553 $mt = microtime(); 554 $rand = mt_rand(); 555 556 return md5($mt.$rand); // md5s look nicer than numbers 557 } 558 } 559 560 class OAuthServer { 561 protected $timestamp_threshold = 300; // in seconds, five minutes 562 protected $version = 1.0; // hi blaine 563 protected $signature_methods = array(); 564 protected $data_store; 565 566 function __construct($data_store) { 567 $this->data_store = $data_store; 568 } 569 570 public function add_signature_method($signature_method) { 571 $this->signature_methods[$signature_method->get_name()] = $signature_method; 572 } 573 574 // high level functions 575 576 /** 577 * process a request_token request 578 * returns the request token on success 579 */ 580 public function fetch_request_token(&$request) { 581 $this->get_version($request); 582 583 $consumer = $this->get_consumer($request); 584 585 // no token required for the initial token request 586 $token = null; 587 588 $this->check_signature($request, $consumer, $token); 589 590 $new_token = $this->data_store->new_request_token($consumer); 591 592 return $new_token; 593 } 594 595 /** 596 * process an access_token request 597 * returns the access token on success 598 */ 599 public function fetch_access_token(&$request) { 600 $this->get_version($request); 601 602 $consumer = $this->get_consumer($request); 603 604 // requires authorized request token 605 $token = $this->get_token($request, $consumer, "request"); 606 607 $this->check_signature($request, $consumer, $token); 608 609 $new_token = $this->data_store->new_access_token($token, $consumer); 610 611 return $new_token; 612 } 613 614 /** 615 * verify an api call, checks all the parameters 616 */ 617 public function verify_request(&$request) { 618 global $lastcomputedsignature; 619 $lastcomputedsignature = false; 620 $this->get_version($request); 621 $consumer = $this->get_consumer($request); 622 $token = $this->get_token($request, $consumer, "access"); 623 $this->check_signature($request, $consumer, $token); 624 return array( 625 $consumer, 626 $token 627 ); 628 } 629 630 // Internals from here 631 /** 632 * version 1 633 */ 634 private function get_version(&$request) { 635 $version = $request->get_parameter("oauth_version"); 636 if (!$version) { 637 $version = 1.0; 638 } 639 if ($version && $version != $this->version) { 640 throw new OAuthException("OAuth version '$version' not supported"); 641 } 642 return $version; 643 } 644 645 /** 646 * figure out the signature with some defaults 647 */ 648 private function get_signature_method(&$request) { 649 $signature_method = @ $request->get_parameter("oauth_signature_method"); 650 if (!$signature_method) { 651 $signature_method = "PLAINTEXT"; 652 } 653 if (!in_array($signature_method, array_keys($this->signature_methods))) { 654 throw new OAuthException("Signature method '$signature_method' not supported " . 655 "try one of the following: " . 656 implode(", ", array_keys($this->signature_methods))); 657 } 658 return $this->signature_methods[$signature_method]; 659 } 660 661 /** 662 * try to find the consumer for the provided request's consumer key 663 */ 664 private function get_consumer(&$request) { 665 $consumer_key = @ $request->get_parameter("oauth_consumer_key"); 666 if (!$consumer_key) { 667 throw new OAuthException("Invalid consumer key"); 668 } 669 670 $consumer = $this->data_store->lookup_consumer($consumer_key); 671 if (!$consumer) { 672 throw new OAuthException("Invalid consumer"); 673 } 674 675 return $consumer; 676 } 677 678 /** 679 * try to find the token for the provided request's token key 680 */ 681 private function get_token(&$request, $consumer, $token_type = "access") { 682 $token_field = @ $request->get_parameter('oauth_token'); 683 if (!$token_field) { 684 return false; 685 } 686 $token = $this->data_store->lookup_token($consumer, $token_type, $token_field); 687 if (!$token) { 688 throw new OAuthException("Invalid $token_type token: $token_field"); 689 } 690 return $token; 691 } 692 693 /** 694 * all-in-one function to check the signature on a request 695 * should guess the signature method appropriately 696 */ 697 private function check_signature(&$request, $consumer, $token) { 698 // this should probably be in a different method 699 global $lastcomputedsignature; 700 $lastcomputedsignature = false; 701 702 $timestamp = @ $request->get_parameter('oauth_timestamp'); 703 $nonce = @ $request->get_parameter('oauth_nonce'); 704 705 $this->check_timestamp($timestamp); 706 $this->check_nonce($consumer, $token, $nonce, $timestamp); 707 708 $signature_method = $this->get_signature_method($request); 709 710 $signature = $request->get_parameter('oauth_signature'); 711 $valid_sig = $signature_method->check_signature($request, $consumer, $token, $signature); 712 713 if (!$valid_sig) { 714 $ex_text = "Invalid signature"; 715 if ($lastcomputedsignature) { 716 $ex_text = $ex_text . " ours= $lastcomputedsignature yours=$signature"; 717 } 718 throw new OAuthException($ex_text); 719 } 720 } 721 722 /** 723 * check that the timestamp is new enough 724 */ 725 private function check_timestamp($timestamp) { 726 // verify that timestamp is recentish 727 $now = time(); 728 if ($now - $timestamp > $this->timestamp_threshold) { 729 throw new OAuthException("Expired timestamp, yours $timestamp, ours $now"); 730 } 731 } 732 733 /** 734 * check that the nonce is not repeated 735 */ 736 private function check_nonce($consumer, $token, $nonce, $timestamp) { 737 // verify that the nonce is uniqueish 738 $found = $this->data_store->lookup_nonce($consumer, $token, $nonce, $timestamp); 739 if ($found) { 740 throw new OAuthException("Nonce already used: $nonce"); 741 } 742 } 743 744 } 745 746 class OAuthDataStore { 747 function lookup_consumer($consumer_key) { 748 // implement me 749 } 750 751 function lookup_token($consumer, $token_type, $token) { 752 // implement me 753 } 754 755 function lookup_nonce($consumer, $token, $nonce, $timestamp) { 756 // implement me 757 } 758 759 function new_request_token($consumer) { 760 // return a new token attached to this consumer 761 } 762 763 function new_access_token($token, $consumer) { 764 // return a new access token attached to this consumer 765 // for the user associated with this token if the request token 766 // is authorized 767 // should also invalidate the request token 768 } 769 770 } 771 772 class OAuthUtil { 773 public static function urlencode_rfc3986($input) { 774 if (is_array($input)) { 775 return array_map(array( 776 'moodle\mod\lti\OAuthUtil', 777 'urlencode_rfc3986' 778 ), $input); 779 } else { 780 if (is_scalar($input)) { 781 return str_replace('+', ' ', str_replace('%7E', '~', rawurlencode($input))); 782 } else { 783 return ''; 784 } 785 } 786 } 787 788 // This decode function isn't taking into consideration the above 789 // modifications to the encoding process. However, this method doesn't 790 // seem to be used anywhere so leaving it as is. 791 public static function urldecode_rfc3986($string) { 792 return urldecode($string); 793 } 794 795 // Utility function for turning the Authorization: header into 796 // parameters, has to do some unescaping 797 // Can filter out any non-oauth parameters if needed (default behaviour) 798 public static function split_header($header, $only_allow_oauth_parameters = true) { 799 $pattern = '/(([-_a-z]*)=("([^"]*)"|([^,]*)),?)/'; 800 $offset = 0; 801 $params = array(); 802 while (preg_match($pattern, $header, $matches, PREG_OFFSET_CAPTURE, $offset) > 0) { 803 $match = $matches[0]; 804 $header_name = $matches[2][0]; 805 $header_content = (isset($matches[5])) ? $matches[5][0] : $matches[4][0]; 806 if (preg_match('/^oauth_/', $header_name) || !$only_allow_oauth_parameters) { 807 $params[$header_name] = self::urldecode_rfc3986($header_content); 808 } 809 $offset = $match[1] + strlen($match[0]); 810 } 811 812 if (isset($params['realm'])) { 813 unset($params['realm']); 814 } 815 816 return $params; 817 } 818 819 // helper to try to sort out headers for people who aren't running apache 820 public static function get_headers() { 821 if (function_exists('apache_request_headers')) { 822 // we need this to get the actual Authorization: header 823 // because apache tends to tell us it doesn't exist 824 $in = apache_request_headers(); 825 $out = array(); 826 foreach ($in as $key => $value) { 827 $key = str_replace(" ", "-", ucwords(strtolower(str_replace("-", " ", $key)))); 828 $out[$key] = $value; 829 } 830 return $out; 831 } 832 // otherwise we don't have apache and are just going to have to hope 833 // that $_SERVER actually contains what we need 834 $out = array(); 835 foreach ($_SERVER as $key => $value) { 836 if (substr($key, 0, 5) == "HTTP_") { 837 // this is chaos, basically it is just there to capitalize the first 838 // letter of every word that is not an initial HTTP and strip HTTP 839 // code from przemek 840 $key = str_replace(" ", "-", ucwords(strtolower(str_replace("_", " ", substr($key, 5))))); 841 $out[$key] = $value; 842 } 843 } 844 return $out; 845 } 846 847 // This function takes a input like a=b&a=c&d=e and returns the parsed 848 // parameters like this 849 // array('a' => array('b','c'), 'd' => 'e') 850 public static function parse_parameters($input) { 851 if (!isset($input) || !$input) { 852 return array(); 853 } 854 855 $pairs = explode('&', $input); 856 857 $parsed_parameters = array(); 858 foreach ($pairs as $pair) { 859 $split = explode('=', $pair, 2); 860 $parameter = self::urldecode_rfc3986($split[0]); 861 $value = isset($split[1]) ? self::urldecode_rfc3986($split[1]) : ''; 862 863 if (isset($parsed_parameters[$parameter])) { 864 // We have already recieved parameter(s) with this name, so add to the list 865 // of parameters with this name 866 867 if (is_scalar($parsed_parameters[$parameter])) { 868 // This is the first duplicate, so transform scalar (string) into an array 869 // so we can add the duplicates 870 $parsed_parameters[$parameter] = array( 871 $parsed_parameters[$parameter] 872 ); 873 } 874 875 $parsed_parameters[$parameter][] = $value; 876 } else { 877 $parsed_parameters[$parameter] = $value; 878 } 879 } 880 return $parsed_parameters; 881 } 882 883 public static function build_http_query($params) { 884 if (!$params) { 885 return ''; 886 } 887 888 // Urlencode both keys and values 889 $keys = self::urlencode_rfc3986(array_keys($params)); 890 $values = self::urlencode_rfc3986(array_values($params)); 891 $params = array_combine($keys, $values); 892 893 // Parameters are sorted by name, using lexicographical byte value ordering. 894 // Ref: Spec: 9.1.1 (1) 895 uksort($params, 'strcmp'); 896 897 $pairs = array(); 898 foreach ($params as $parameter => $value) { 899 if (is_array($value)) { 900 // If two or more parameters share the same name, they are sorted by their value 901 // Ref: Spec: 9.1.1 (1) 902 natsort($value); 903 foreach ($value as $duplicate_value) { 904 $pairs[] = $parameter . '=' . $duplicate_value; 905 } 906 } else { 907 $pairs[] = $parameter . '=' . $value; 908 } 909 } 910 // For each parameter, the name is separated from the corresponding value by an '=' character (ASCII code 61) 911 // Each name-value pair is separated by an '&' character (ASCII code 38) 912 return implode('&', $pairs); 913 } 914 }
title
Description
Body
title
Description
Body
title
Description
Body
title
Body
