cognito lambda triggers

cognito-lambda-triggers.ts

// Cognito lambdas triggers
// Create auth challenge Lambda trigger
var AWS = require("aws-sdk");
exports.handler = (event, context, callback) => {
  event.response.publicChallengeParameters = {};
  event.response.privateChallengeParameters = {};
  const session = event.request.session;
  const currentSession = session ? session.length - 1 : 0;
  const MAX_ATTEMPTS = 3;

  if (
    event.request.session.length == 0 &&
    event.request.challengeName == "CUSTOM_CHALLENGE"
  ) {
    //create the code
    var answer = Math.random().toString(10).substr(2, 6);

    // send answer via sms
    // sendCode(answer) using something like aws sdk

    //set the return parameters **including the correct answer**
    event.response.privateChallengeParameters.answer = answer;
    event.response.challengeMetadata = answer;
    event.response.publicChallengeParameters = {
      challengeType: "PASSWORDLESS_CHALLENGE",
      phone_number: event.request.userAttributes.phone_number,
      attempts: 1,
      attemptsLeft: 2,
    };
  } else {
    const attempts = session.length;
    const attemptsLeft = MAX_ATTEMPTS - attempts;
    const metaData = session[currentSession].challengeMetadata;
    if (attempts < MAX_ATTEMPTS) {
      event.response.privateChallengeParameters.answer = metaData;
      event.response.challengeMetadata = metaData;
      event.response.publicChallengeParameters = {
        challengeType: "PASSWORDLESS_CHALLENGE",
        phone_number: event.request.userAttributes.phone_number,
        attempts,
        attemptsLeft,
      };
    }
  }

  callback(null, event);
};


// Define auth challenge Lambda trigger
exports.handler = (event, context, callback) => {
    const session = event.request.session
    const currentSession = session ? session.length - 1 : 0
    const attempts = session.length;
    const MAX_ATTEMPTS = 3;
    
     if (session.length === 0) {
          event.response = {
            challengeName: "CUSTOM_CHALLENGE",
            failAuthentication: false,
            issueTokens: false,
          };
        } else {
          if (session[currentSession].challengeName === "CUSTOM_CHALLENGE") {
            if (session[currentSession].challengeResult === true) {
              event.response.issueTokens = true;
              event.response.failAuthentication = false;
            } else {
              if (attempts <= MAX_ATTEMPTS) {
                event.response = {
                  challengeName: "CUSTOM_CHALLENGE",
                  failAuthentication: false,
                  issueTokens: false,
                };
              } else {
                event.response.issueTokens = false;
                event.response.failAuthentication = true;
              }
            }
          }
        }
   
    callback(null, event);
  }

// Verify auth challenge response Lambda trigger
  exports.handler = (event, context, callback) => {
    if (event.request.privateChallengeParameters.answer == event.request.challengeAnswer) {
        event.response.answerCorrect = true;
    } else {
        event.response.answerCorrect = false;
    }
    callback(null, event);
}