Util.php

<?php
 
namespace ceLTIc\LTI;
 
use ceLTIc\LTI\OAuth;
 
final class Util
{
 
    const LTI_VERSION1 = 'LTI-1p0';
 
    const LTI_VERSION1P3 = '1.3.0';
 
    const LTI_VERSION2 = 'LTI-2p0';
 
    const JWT_CLAIM_PREFIX = 'https://purl.imsglobal.org/spec/lti';
 
    const MESSAGE_TYPE_MAPPING = array(
        'basic-lti-launch-request' => 'LtiResourceLinkRequest',
        'ContentItemSelectionRequest' => 'LtiDeepLinkingRequest',
        'ContentItemSelection' => 'LtiDeepLinkingResponse',
        'ContentItemUpdateRequest' => 'LtiDeepLinkingUpdateRequest'
    );
 
    const JWT_CLAIM_MAPPING = array(
        'accept_types' => array('suffix' => 'dl', 'group' => 'deep_linking_settings', 'claim' => 'accept_types', 'isArray' => true),
        'accept_copy_advice' => array('suffix' => 'dl', 'group' => 'deep_linking_settings', 'claim' => 'copyAdvice', 'isBoolean' => true),
        'accept_media_types' => array('suffix' => 'dl', 'group' => 'deep_linking_settings', 'claim' => 'accept_media_types'),
        'accept_multiple' => array('suffix' => 'dl', 'group' => 'deep_linking_settings', 'claim' => 'accept_multiple', 'isBoolean' => true),
        'accept_presentation_document_targets' => array('suffix' => 'dl', 'group' => 'deep_linking_settings', 'claim' => 'accept_presentation_document_targets', 'isArray' => true),
        'accept_unsigned' => array('suffix' => 'dl', 'group' => 'deep_linking_settings', 'claim' => 'accept_unsigned', 'isBoolean' => true),
        'auto_create' => array('suffix' => 'dl', 'group' => 'deep_linking_settings', 'claim' => 'auto_create', 'isBoolean' => true),
        'can_confirm' => array('suffix' => 'dl', 'group' => 'deep_linking_settings', 'claim' => 'can_confirm'),
        'content_item_return_url' => array('suffix' => 'dl', 'group' => 'deep_linking_settings', 'claim' => 'deep_link_return_url'),
        'content_items' => array('suffix' => 'dl', 'group' => '', 'claim' => 'content_items', 'isObject' => true),
        'data' => array('suffix' => 'dl', 'group' => 'deep_linking_settings', 'claim' => 'data'),
        'data.LtiDeepLinkingResponse' => array('suffix' => 'dl', 'group' => '', 'claim' => 'data'),
        'text' => array('suffix' => 'dl', 'group' => 'deep_linking_settings', 'claim' => 'text'),
        'title' => array('suffix' => 'dl', 'group' => 'deep_linking_settings', 'claim' => 'title'),
        'lti_msg' => array('suffix' => 'dl', 'group' => '', 'claim' => 'msg'),
        'lti_errormsg' => array('suffix' => 'dl', 'group' => '', 'claim' => 'errormsg'),
        'lti_log' => array('suffix' => 'dl', 'group' => '', 'claim' => 'log'),
        'lti_errorlog' => array('suffix' => 'dl', 'group' => '', 'claim' => 'errorlog'),
        'context_id' => array('suffix' => '', 'group' => 'context', 'claim' => 'id'),
        'context_label' => array('suffix' => '', 'group' => 'context', 'claim' => 'label'),
        'context_title' => array('suffix' => '', 'group' => 'context', 'claim' => 'title'),
        'context_type' => array('suffix' => '', 'group' => 'context', 'claim' => 'type', 'isArray' => true),
        'lis_course_offering_sourcedid' => array('suffix' => '', 'group' => 'lis', 'claim' => 'course_offering_sourcedid'),
        'lis_course_section_sourcedid' => array('suffix' => '', 'group' => 'lis', 'claim' => 'course_section_sourcedid'),
        'launch_presentation_css_url' => array('suffix' => '', 'group' => 'launch_presentation', 'claim' => 'css_url'),
        'launch_presentation_document_target' => array('suffix' => '', 'group' => 'launch_presentation', 'claim' => 'document_target'),
        'launch_presentation_height' => array('suffix' => '', 'group' => 'launch_presentation', 'claim' => 'height', 'isInteger' => true),
        'launch_presentation_locale' => array('suffix' => '', 'group' => 'launch_presentation', 'claim' => 'locale'),
        'launch_presentation_return_url' => array('suffix' => '', 'group' => 'launch_presentation', 'claim' => 'return_url'),
        'launch_presentation_width' => array('suffix' => '', 'group' => 'launch_presentation', 'claim' => 'width', 'isInteger' => true),
        'lis_person_contact_email_primary' => array('suffix' => '', 'group' => null, 'claim' => 'email'),
        'lis_person_name_family' => array('suffix' => '', 'group' => null, 'claim' => 'family_name'),
        'lis_person_name_full' => array('suffix' => '', 'group' => null, 'claim' => 'name'),
        'lis_person_name_given' => array('suffix' => '', 'group' => null, 'claim' => 'given_name'),
        'lis_person_name_middle' => array('suffix' => '', 'group' => null, 'claim' => 'middle_name'),
        'lis_person_sourcedid' => array('suffix' => '', 'group' => 'lis', 'claim' => 'person_sourcedid'),
        'user_id' => array('suffix' => '', 'group' => null, 'claim' => 'sub'),
        'user_image' => array('suffix' => '', 'group' => null, 'claim' => 'picture'),
        'roles' => array('suffix' => '', 'group' => '', 'claim' => 'roles', 'isArray' => true),
        'role_scope_mentor' => array('suffix' => '', 'group' => '', 'claim' => 'role_scope_mentor', 'isArray' => true),
        'platform_id' => array('suffix' => '', 'group' => null, 'claim' => 'iss'),
        'deployment_id' => array('suffix' => '', 'group' => '', 'claim' => 'deployment_id'),
        'lti_message_type' => array('suffix' => '', 'group' => '', 'claim' => 'message_type'),
        'lti_version' => array('suffix' => '', 'group' => '', 'claim' => 'version'),
        'resource_link_description' => array('suffix' => '', 'group' => 'resource_link', 'claim' => 'description'),
        'resource_link_id' => array('suffix' => '', 'group' => 'resource_link', 'claim' => 'id'),
        'resource_link_title' => array('suffix' => '', 'group' => 'resource_link', 'claim' => 'title'),
        'target_link_uri' => array('suffix' => '', 'group' => '', 'claim' => 'target_link_uri'),
        'tool_consumer_info_product_family_code' => array('suffix' => '', 'group' => 'tool_platform', 'claim' => 'product_family_code'),
        'tool_consumer_info_version' => array('suffix' => '', 'group' => 'tool_platform', 'claim' => 'version'),
        'tool_consumer_instance_contact_email' => array('suffix' => '', 'group' => 'tool_platform', 'claim' => 'contact_email'),
        'tool_consumer_instance_description' => array('suffix' => '', 'group' => 'tool_platform', 'claim' => 'description'),
        'tool_consumer_instance_guid' => array('suffix' => '', 'group' => 'tool_platform', 'claim' => 'guid'),
        'tool_consumer_instance_name' => array('suffix' => '', 'group' => 'tool_platform', 'claim' => 'name'),
        'tool_consumer_instance_url' => array('suffix' => '', 'group' => 'tool_platform', 'claim' => 'url'),
        'for_user_contact_email_primary' => array('suffix' => '', 'group' => 'for_user', 'claim' => 'email'),
        'for_user_name_family' => array('suffix' => '', 'group' => 'for_user', 'claim' => 'family_name'),
        'for_user_name_full' => array('suffix' => '', 'group' => 'for_user', 'claim' => 'name'),
        'for_user_name_given' => array('suffix' => '', 'group' => 'for_user', 'claim' => 'given_name'),
        'for_user_name_middle' => array('suffix' => '', 'group' => 'for_user', 'claim' => 'middle_name'),
        'for_user_sourcedid' => array('suffix' => '', 'group' => 'for_user', 'claim' => 'person_sourcedid'),
        'for_user_id' => array('suffix' => '', 'group' => 'for_user', 'claim' => 'user_id'),
        'for_user_roles' => array('suffix' => '', 'group' => 'for_user', 'claim' => 'roles', 'isArray' => true),
        'tool_state' => array('suffix' => '', 'group' => 'tool', 'claim' => 'state'),
        'custom_context_memberships_v2_url' => array('suffix' => 'nrps', 'group' => 'namesroleservice', 'claim' => 'context_memberships_url'),
        'custom_nrps_versions' => array('suffix' => 'nrps', 'group' => 'namesroleservice', 'claim' => 'service_versions', 'isArray' => true),
        'custom_lineitems_url' => array('suffix' => 'ags', 'group' => 'endpoint', 'claim' => 'lineitems'),
        'custom_lineitem_url' => array('suffix' => 'ags', 'group' => 'endpoint', 'claim' => 'lineitem'),
        'custom_ags_scopes' => array('suffix' => 'ags', 'group' => 'endpoint', 'claim' => 'scope', 'isArray' => true),
        'custom_context_groups_url' => array('suffix' => 'gs', 'group' => 'groupsservice', 'claim' => 'context_groups_url'),
        'custom_context_group_sets_url' => array('suffix' => 'gs', 'group' => 'groupsservice', 'claim' => 'context_group_sets_url'),
        'custom_gs_scopes' => array('suffix' => 'gs', 'group' => 'groupsservice', 'claim' => 'scope', 'isArray' => true),
        'custom_gs_versions' => array('suffix' => 'gs', 'group' => 'groupsservice', 'claim' => 'service_versions', 'isArray' => true),
        'lis_outcome_service_url' => array('suffix' => 'bo', 'group' => 'basicoutcome', 'claim' => 'lis_outcome_service_url'),
        'lis_result_sourcedid' => array('suffix' => 'bo', 'group' => 'basicoutcome', 'claim' => 'lis_result_sourcedid'),
        'custom_ap_attempt_number' => array('suffix' => 'ap', 'group' => '', 'claim' => 'attempt_number', 'isInteger' => true),
        'custom_ap_start_assessment_url' => array('suffix' => 'ap', 'group' => '', 'claim' => 'start_assessment_url'),
        'custom_ap_session_data' => array('suffix' => 'ap', 'group' => '', 'claim' => 'session_data'),
        'custom_ap_acs_actions' => array('suffix' => 'ap', 'group' => 'acs', 'claim' => 'actions', 'isArray' => true),
        'custom_ap_acs_url' => array('suffix' => 'ap', 'group' => 'acs', 'claim' => 'assessment_control_url'),
        'custom_ap_proctoring_settings_data' => array('suffix' => 'ap', 'group' => 'proctoring_settings', 'claim' => 'data'),
        'custom_ap_email_verified' => array('suffix' => '', 'group' => null, 'claim' => 'email_verified', 'isBoolean' => true),
        'custom_ap_verified_user_given_name' => array('suffix' => 'ap', 'group' => 'verified_user', 'claim' => 'given_name'),
        'custom_ap_verified_user_middle_name' => array('suffix' => 'ap', 'group' => 'verified_user', 'claim' => 'middle_name'),
        'custom_ap_verified_user_family_name' => array('suffix' => 'ap', 'group' => 'verified_user', 'claim' => 'family_name'),
        'custom_ap_verified_user_full_name' => array('suffix' => 'ap', 'group' => 'verified_user', 'claim' => 'full_name'),
        'custom_ap_verified_user_image' => array('suffix' => 'ap', 'group' => 'verified_user', 'claim' => 'picture'),
        'custom_ap_end_assessment_return' => array('suffix' => 'ap', 'group' => '', 'claim' => 'end_assessment_return', 'isBoolean' => true)
    );
 
    const LOGLEVEL_NONE = 0;
 
    const LOGLEVEL_ERROR = 1;
 
    const LOGLEVEL_INFO = 2;
 
    const LOGLEVEL_DEBUG = 3;
 
    const TEST_COOKIE_NAME = 'celtic_lti_test_cookie';
 
    public static $LTI_VERSIONS = array(self::LTI_VERSION1, self::LTI_VERSION1P3, self::LTI_VERSION2);
 
    public static $METHOD_NAMES = array(
        'basic-lti-launch-request' => 'onLaunch',
        'ConfigureLaunchRequest' => 'onConfigure',
        'DashboardRequest' => 'onDashboard',
        'ContentItemSelectionRequest' => 'onContentItem',
        'ContentItemSelection' => 'onContentItem',
        'ContentItemUpdateRequest' => 'onContentItemUpdate',
        'LtiSubmissionReviewRequest' => 'onSubmissionReview',
        'ToolProxyRegistrationRequest' => 'onRegister',
        'LtiStartProctoring' => 'onLtiStartProctoring',
        'LtiStartAssessment' => 'onLtiStartAssessment',
        'LtiEndAssessment' => 'onLtiEndAssessment'
    );
 
    public static $requestParameters = null;
 
    public static $logLevel = self::LOGLEVEL_NONE;
 
    public static $formSubmissionTimeout = 2;
 
    public static function isLtiMessage()
    {
        $isLti = ($_SERVER['REQUEST_METHOD'] === 'POST') &&
            (!empty($_POST['lti_message_type']) || !empty($_POST['id_token']) || !empty($_POST['JWT']) ||
            !empty($_POST['iss']));
        if (!$isLti) {
            $isLti = ($_SERVER['REQUEST_METHOD'] === 'GET') && (!empty($_GET['iss']) || !empty($_GET['openid_configuration']));
        }
 
        return $isLti;
    }
 
    public static function getRequestParameters()
    {
        if (is_null(self::$requestParameters)) {
            self::$requestParameters = array_merge($_GET, $_POST);
        }
 
        return self::$requestParameters;
    }
 
    public static function logError($message, $showSource = true)
    {
        if (self::$logLevel >= self::LOGLEVEL_ERROR) {
            self::log("[ERROR] {$message}", $showSource);
        }
    }
 
    public static function logInfo($message, $showSource = false)
    {
        if (self::$logLevel >= self::LOGLEVEL_INFO) {
            self::log("[INFO] {$message}", $showSource);
        }
    }
 
    public static function logDebug($message, $showSource = false)
    {
        if (self::$logLevel >= self::LOGLEVEL_DEBUG) {
            self::log("[DEBUG] {$message}", $showSource);
        }
    }
 
    public static function logRequest($debugLevel = false)
    {
        if (!$debugLevel) {
            $logLevel = self::LOGLEVEL_INFO;
        } else {
            $logLevel = self::LOGLEVEL_DEBUG;
        }
        if (self::$logLevel >= $logLevel) {
            $message = "{$_SERVER['REQUEST_METHOD']} request received for '{$_SERVER['REQUEST_URI']}'";
            $body = file_get_contents(OAuth\OAuthRequest::$POST_INPUT);
            if (!empty($body)) {
                $params = OAuth\OAuthUtil::parse_parameters($body);
                if (!empty($params)) {
                    $message .= " with body parameters of:\n" . var_export($params, true);
                } else {
                    $message .= " with a body of:\n" . var_export($body, true);
                }
            }
            if (!$debugLevel) {
                self::logInfo($message);
            } else {
                self::logDebug($message);
            }
        }
    }
 
    public static function logForm($url, $params, $method = 'POST', $debugLevel = false)
    {
        if (!$debugLevel) {
            $logLevel = self::$logLevel;
        } else {
            $logLevel = self::LOGLEVEL_DEBUG;
        }
        if (self::$logLevel >= self::LOGLEVEL_INFO) {
            $message = "Form submitted using {$method} to '{$url}'";
            if (!empty($params)) {
                $message .= " with parameters of:\n" . var_export($params, true);
            } else {
                $message .= " with no parameters";
            }
            if ($logLevel < self::LOGLEVEL_DEBUG) {
                self::logInfo($message);
            } else {
                self::logDebug($message);
            }
        }
    }
 
    public static function log($message, $showSource = false)
    {
        $source = '';
        if ($showSource) {
            $backtraces = debug_backtrace();
            foreach ($backtraces as $backtrace) {
                if (isset($backtrace['file'])) {
                    $source .= PHP_EOL . "  {$backtrace['file']}";
                    if (isset($backtrace['line'])) {
                        $source .= " line {$backtrace['line']}";
                    }
                }
            }
            if (!empty($source)) {
                $source = PHP_EOL . "See: {$source}";
            }
        }
        error_log($message . $source);
    }
 
    public static function sendForm($url, $params, $target = '', $javascript = '')
    {
        $timeout = static::$formSubmissionTimeout;
        if (empty($javascript)) {
            $javascript = <<< EOD
function doUnblock() {
  var el = document.getElementById('id_blocked');
  el.style.display = 'block';
}
 
function doOnLoad() {
  if ((document.forms[0].target === '_blank') && (window.top === window.self)) {
    document.forms[0].target = '';
  }
  window.setTimeout(doUnblock, {$timeout}000);
  document.forms[0].submit();
}
 
window.onload=doOnLoad;
EOD;
        }
        self::logForm($url, $params, 'POST');
        $page = <<< EOD
<!DOCTYPE html>
<head>
<title>1EdTech LTI message</title>
<script type="text/javascript">
{$javascript}
</script>
</head>
<body>
  <form action="{$url}" method="post" target="{$target}" encType="application/x-www-form-urlencoded">
    <p id="id_blocked" style="display: none; color: red; font-weight: bold;">
      Your browser may be blocking this request; try clicking the button below.<br><br>
      <input type="submit" value="Continue" />
    </p>
 
EOD;
        if (!empty($params)) {
            foreach ($params as $key => $value) {
                $key = htmlentities($key, ENT_COMPAT | ENT_HTML401, 'UTF-8');
                if (!is_array($value)) {
                    $value = htmlentities($value, ENT_COMPAT | ENT_HTML401, 'UTF-8');
                    $page .= <<< EOD
    <input type="hidden" name="{$key}" id="id_{$key}" value="{$value}" />
 
EOD;
                } else {
                    foreach ($value as $element) {
                        $element = htmlentities($element, ENT_COMPAT | ENT_HTML401, 'UTF-8');
                        $page .= <<< EOD
    <input type="hidden" name="{$key}" value="{$element}" />
 
EOD;
                    }
                }
            }
        }
 
        $page .= <<< EOD
  </form>
</body>
</html>
EOD;
 
        return $page;
    }
 
    public static function redirect($url, $params)
    {
        if (!empty($params)) {
            if (strpos($url, '?') === false) {
                $url .= '?';
                $sep = '';
            } else {
                $sep = '&';
            }
            foreach ($params as $key => $value) {
                $key = urlencode($key);
                if (!is_array($value)) {
                    $value = urlencode($value);
                    $url .= "{$sep}{$key}={$value}";
                    $sep = '&';
                } else {
                    foreach ($value as $element) {
                        $element = urlencode($element);
                        $url .= "{$sep}{$key}={$element}";
                        $sep = '&';
                    }
                }
            }
        }
 
        header("Location: {$url}");
        exit;
    }
 
    public static function setTestCookie($delete = false)
    {
        if (!$delete || isset($_COOKIE[self::TEST_COOKIE_NAME])) {
            $oauthRequest = OAuth\OAuthRequest::from_request();
            $url = $oauthRequest->get_normalized_http_url();
            $secure = (parse_url($url, PHP_URL_SCHEME) === 'https');
            $path = parse_url($url, PHP_URL_PATH);
            if (empty($path)) {
                $path = '/';
            } elseif (substr($path, -1) == '/') {
                $path = substr($path, 0, -1);
            }
            if (!$delete) {
                $expires = 0;
            } else {
                $expires = time() - 3600;
            }
            if ((PHP_MAJOR_VERSION > 7) || ((PHP_MAJOR_VERSION >= 7) && (PHP_MINOR_VERSION >= 3))) {  // PHP 7.3 or later?
                setcookie(self::TEST_COOKIE_NAME, 'LTI cookie check',
                    array('expires' => $expires, 'path' => $path, 'domain' => $_SERVER['HTTP_HOST'], 'secure' => $secure, 'httponly' => true, 'SameSite' => 'None'));
            } else {
                setcookie(self::TEST_COOKIE_NAME, 'LTI cookie check', $expires, $path, $_SERVER['HTTP_HOST'], $secure);
            }
        }
    }
 
    public static function getRandomString($length = 8)
    {
        $chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
 
        $value = '';
        $charsLength = strlen($chars) - 1;
 
        for ($i = 1; $i <= $length; $i++) {
            $value .= $chars[rand(0, $charsLength)];
        }
 
        return $value;
    }
 
    public static function stripHtml($html)
    {
        $html = strip_tags($html);
        $html = html_entity_decode($html, ENT_QUOTES | ENT_HTML401);
 
        return $html;
    }
 
    public static function jsonDecode($str, $associative = false)
    {
        if (!empty($str)) {
            $json = \json_decode($str, $associative);
        } else {
            $json = null;
        }
 
        return $json;
    }
 
    public static function cloneObject($obj)
    {
        $clone = clone $obj;
        $objVars = get_object_vars($clone);
        foreach ($objVars as $attrName => $attrValue) {
            if (is_object($clone->$attrName)) {
                $clone->$attrName = self::cloneObject($clone->$attrName);
            } else if (is_array($clone->$attrName)) {
                foreach ($clone->$attrName as &$attrArrayValue) {
                    if (is_object($attrArrayValue)) {
                        $attrArrayValue = self::cloneObject($attrArrayValue);
                    }
                    unset($attrArrayValue);
                }
            }
        }
 
        return $clone;
    }
 
}