@atomicjolt/lti-client/src/client/launch.ts

Client Javascript libraries to handle LTI.

import { LaunchSettings } from "../types";
import { loadState } from "../libs/platform_storage";

async function validateLaunch(settings: LaunchSettings): Promise<boolean> {
  if (settings.ltiStorageParams) {
    // We have lti postMessage storage
    try {
      console.log("Using postMessage state validation");
      const state = await loadState(settings.state, settings.ltiStorageParams);
      if (state == settings.state) {
        return true;
      }
      return false;
    } catch (e) {
      console.error(e);
      return false;
    }
  }
  return false;
}

export async function ltiLaunch(settings: LaunchSettings): Promise<boolean> {
  if (!settings.stateVerified) {
    const result = await validateLaunch(settings);
    return result;
  }
  return true;
}