Current Path : C:/xampp/htdocs/moodle/enrol/lti/ims-blti/ |
Current File : C:/xampp/htdocs/moodle/enrol/lti/ims-blti/blti.php |
<?php require_once($CFG->dirroot . '/enrol/lti/ims-blti/OAuth.php'); require_once($CFG->dirroot . '/enrol/lti/ims-blti/TrivialOAuthDataStore.php'); // Returns true if this is a Basic LTI message // with minimum values to meet the protocol function is_basic_lti_request() { $good_message_type = $_REQUEST["lti_message_type"] == "basic-lti-launch-request"; $good_lti_version = ($_REQUEST["lti_version"] == "LTI-1p0" or $_REQUEST["lti_version"] == "LTI-1.0"); $good_lti_version = $good_lti_version || ($_REQUEST["lti_version"] == "LTI-2p0" or $_REQUEST["lti_version"] == "LTI-2.0"); $resource_link_id = $_REQUEST["resource_link_id"]; if ($good_message_type and $good_lti_version and isset($resource_link_id) ) return(true); return false; } // Basic LTI Class that does the setup and provides utility // functions class BLTI { public $valid = false; public $complete = false; public $message = false; public $basestring = false; public $info = false; public $row = false; public $context_id = false; // Override context_id function __construct($parm=false, $usesession=true, $doredirect=true) { // If this request is not an LTI Launch, either // give up or try to retrieve the context from session if ( ! is_basic_lti_request() ) { if ( $usesession === false ) return; if ( strlen(session_id()) > 0 ) { $row = $_SESSION['_basiclti_lti_row']; if ( isset($row) ) $this->row = $row; $context_id = $_SESSION['_basiclti_lti_context_id']; if ( isset($context_id) ) $this->context_id = $context_id; $info = $_SESSION['_basic_lti_context']; if ( isset($info) ) { $this->info = $info; $this->valid = true; return; } $this->message = "Could not find context in session"; return; } $this->message = "Session not available"; return; } // Insure we have a valid launch if ( empty($_REQUEST["oauth_consumer_key"]) ) { $this->message = "Missing oauth_consumer_key in request"; return; } $oauth_consumer_key = $_REQUEST["oauth_consumer_key"]; // Find the secret - either form the parameter as a string or // look it up in a database from parameters we are given $secret = false; $row = false; if ( is_string($parm) ) { $secret = $parm; } else if ( ! is_array($parm) ) { $this->message = "Constructor requires a secret or database information."; return; } // Verify the message signature $store = new TrivialOAuthDataStore(); $store->add_consumer($oauth_consumer_key, $secret); $server = new OAuthServer($store); $method = new OAuthSignatureMethod_HMAC_SHA1(); $server->add_signature_method($method); $request = OAuthRequest::from_request(); $this->basestring = $request->get_signature_base_string(); try { $server->verify_request($request); $this->valid = true; } catch (Exception $e) { $this->message = $e->getMessage(); return; } // Store the launch information in the session for later $newinfo = array(); foreach($_POST as $key => $value ) { if ( $key == "basiclti_submit" ) continue; if ( strpos($key, "oauth_") === false ) { $newinfo[$key] = $value; continue; } if ( $key == "oauth_consumer_key" ) { $newinfo[$key] = $value; continue; } } //Added abertranb to decode base 64 20120801 if (isset($newinfo['custom_lti_message_encoded_base64']) && $newinfo['custom_lti_message_encoded_base64']==1){ $newinfo = $this->decodeBase64($newinfo); } $this->info = $newinfo; if ( $usesession == true and strlen(session_id()) > 0 ) { $_SESSION['_basic_lti_context'] = $this->info; unset($_SESSION['_basiclti_lti_row']); unset($_SESSION['_basiclti_lti_context_id']); if ( $this->row ) $_SESSION['_basiclti_lti_row'] = $this->row; if ( $this->context_id ) $_SESSION['_basiclti_lti_context_id'] = $this->context_id; } if ( $this->valid && $doredirect ) { $this->redirect(); $this->complete = true; } } function addSession($location) { if ( ini_get('session.use_cookies') == 0 ) { if ( strpos($location,'?') > 0 ) { $location = $location . '&'; } else { $location = $location . '?'; } $location = $location . session_name() . '=' . session_id(); } return $location; } function isInstructor() { $roles = $this->info['roles']; $roles = strtolower($roles); if ( ! ( strpos($roles,"instructor") === false ) ) return true; if ( ! ( strpos($roles,"administrator") === false ) ) return true; return false; } function getUserEmail() { # set default email in the event privacy settings don't pass in email. $email = $this->info['user_id'] . "@ltiuser.com"; if ( isset($this->info['lis_person_contact_email_primary']) ) $email = $this->info['lis_person_contact_email_primary']; # Sakai Hack if ( isset($this->info['lis_person_contact_emailprimary']) ) $email = $this->info['lis_person_contact_emailprimary']; return $email; } function getUserShortName() { $email = $this->getUserEmail(); $givenname = $this->info['lis_person_name_given']; $familyname = $this->info['lis_person_name_family']; $fullname = $this->info['lis_person_name_full']; if ( strlen($email) > 0 ) return $email; if ( strlen($givenname) > 0 ) return $givenname; if ( strlen($familyname) > 0 ) return $familyname; return $this->getUserName(); } function getUserName() { $givenname = $this->info['lis_person_name_given']; $familyname = $this->info['lis_person_name_family']; $fullname = $this->info['lis_person_name_full']; if ( strlen($fullname) > 0 ) return $fullname; if ( strlen($familyname) > 0 and strlen($givenname) > 0 ) return $givenname + $familyname; if ( strlen($givenname) > 0 ) return $givenname; if ( strlen($familyname) > 0 ) return $familyname; return $this->getUserEmail(); } function getUserKey() { $oauth = $this->info['oauth_consumer_key']; $id = $this->info['user_id']; if ( strlen($id) > 0 and strlen($oauth) > 0 ) return $oauth . ':' . $id; return false; } function getUserImage() { $image = $this->info['user_image']; if ( strlen($image) > 0 ) return $image; $email = $this->getUserEmail(); if ( $email === false ) return false; $size = 40; $grav_url = $_SERVER['HTTPS'] ? 'https://' : 'http://'; $grav_url = $grav_url . "www.gravatar.com/avatar.php?gravatar_id=".md5( strtolower($email) )."&size=".$size; return $grav_url; } function getResourceKey() { $oauth = $this->info['oauth_consumer_key']; $id = $this->info['resource_link_id']; if ( strlen($id) > 0 and strlen($oauth) > 0 ) return $oauth . ':' . $id; return false; } function getResourceTitle() { $title = $this->info['resource_link_title']; if ( strlen($title) > 0 ) return $title; return false; } function getConsumerKey() { $oauth = $this->info['oauth_consumer_key']; return $oauth; } function getCourseKey() { if ( $this->context_id ) return $this->context_id; $oauth = $this->info['oauth_consumer_key']; $id = $this->info['context_id']; if ( strlen($id) > 0 and strlen($oauth) > 0 ) return $oauth . ':' . $id; return false; } function getCourseName() { $label = $this->info['context_label']; $title = $this->info['context_title']; $id = $this->info['context_id']; if ( strlen($label) > 0 ) return $label; if ( strlen($title) > 0 ) return $title; if ( strlen($id) > 0 ) return $id; return false; } // TODO: Add javasript version if headers are already sent function redirect() { $host = $_SERVER['HTTP_HOST']; $uri = $_SERVER['PHP_SELF']; $location = $_SERVER['HTTPS'] ? 'https://' : 'http://'; $location = $location . $host . $uri; $location = $this->addSession($location); header("Location: $location"); } function dump() { if ( ! $this->valid or $this->info == false ) return "Context not valid\n"; $ret = ""; if ( $this->isInstructor() ) { $ret .= "isInstructor() = true\n"; } else { $ret .= "isInstructor() = false\n"; } $ret .= "getUserKey() = ".$this->getUserKey()."\n"; $ret .= "getUserEmail() = ".$this->getUserEmail()."\n"; $ret .= "getUserShortName() = ".$this->getUserShortName()."\n"; $ret .= "getUserName() = ".$this->getUserName()."\n"; $ret .= "getUserImage() = ".$this->getUserImage()."\n"; $ret .= "getResourceKey() = ".$this->getResourceKey()."\n"; $ret .= "getResourceTitle() = ".$this->getResourceTitle()."\n"; $ret .= "getCourseName() = ".$this->getCourseName()."\n"; $ret .= "getCourseKey() = ".$this->getCourseKey()."\n"; $ret .= "getConsumerKey() = ".$this->getConsumerKey()."\n"; return $ret; } /** * Data submitter are in base64 then we have to decode * @author Antoni Bertran (antoni@tresipunt.com) * @param $info array * @date 20120801 */ function decodeBase64($info) { $keysNoEncode = array("lti_version", "lti_message_type", "tool_consumer_instance_description", "tool_consumer_instance_guid", "oauth_consumer_key", "custom_lti_message_encoded_base64", "oauth_nonce", "oauth_version", "oauth_callback", "oauth_timestamp", "basiclti_submit", "oauth_signature_method", "ext_ims_lis_memberships_id", "ext_ims_lis_memberships_url"); foreach ($info as $key => $item){ if (!in_array($key, $keysNoEncode)) $info[$key] = base64_decode($item); } return $info; } } ?>