WebSocket API Gateway Cognito Authorizer

verifyToken.js

import { decode, verify } from 'jsonwebtoken';

export const verifyToken = async (region, userPoolId, token) => {
  var decodedJwt = decode(token, { complete: true });

  if (!decodedJwt || !decodedJwt.header || !decodedJwt.header.kid) {
    return null;
  }

  const pemEncodedPublicKeys = await getPemEncodedPublicKeys(region, userPoolId);
  const pemEncodedPublicKey = pemEncodedPublicKeys.get(decodedJwt.header.kid);

  if (!pemEncodedPublicKey) {
    throw new Error(
      `Public key ID "${decodedJwt.header.kid}" not found for User Pool ID "${userPoolId}" in "${region}" region!`,
    );
  }

  return verify(token, pemEncodedPublicKey);
};