"292832126", "roles" => "Instructor", "resource_link_id" => "120988f929-274612", "resource_link_title" => "Weekly Blog", "resource_link_description" => "A weekly blog.", "lis_person_name_full" => "Jane Q. Public", "lis_person_name_family" => "Public", "lis_person_name_given" => "Given", "lis_person_contact_email_primary" => "user@school.edu", "lis_person_sourcedid" => "school.edu:user", "context_id" => "456434513", "context_title" => "Design of Personal Environments", "context_label" => "SI182", "tool_consumer_instance_guid" => "lmsng.school.edu", "tool_consumer_instance_description" => "University of School (LMSng)" ); # # END OF CONFIGURATION SECTION # ------------------------------ $now = new DateTime(); $launch_data["lti_version"] = "LTI-1p0"; $launch_data["lti_message_type"] = "basic-lti-launch-request"; # Basic LTI uses OAuth to sign requests # OAuth Core 1.0 spec: http://oauth.net/core/1.0/ $launch_data["oauth_callback"] = "about:blank"; $launch_data["oauth_consumer_key"] = $key; $launch_data["oauth_version"] = "1.0"; $launch_data["oauth_nonce"] = uniqid('', true); $launch_data["oauth_timestamp"] = $now->getTimestamp(); $launch_data["oauth_signature_method"] = "HMAC-SHA1"; # In OAuth, request parameters must be sorted by name $launch_data_keys = array_keys($launch_data); sort($launch_data_keys); $launch_params = array(); foreach ($launch_data_keys as $key) { array_push($launch_params, $key . "=" . rawurlencode($launch_data[$key])); } $base_string = "POST&" . urlencode($launch_url) . "&" . rawurlencode(implode("&", $launch_params)); $secret = urlencode($secret) . "&"; $signature = base64_encode(hash_hmac("sha1", $base_string, $secret, true)); ?>