title: Verify AWS id Token on Java
body: <p>i am using Cognito in Amazon to authenticate my mobile users, once they complete the login, Cognito provides a set of tokens, i am using the id token in my backend. I have followed the steps on the section Using ID Tokens and Access Tokens in your Web APIs on
  <a href="https://docs.aws.amazon.com/cognito/latest/developerguide/amazon-cognito-user-pools-using-tokens-with-identity-providers.html" rel="nofollow noreferrer">https://docs.aws.amazon.com/cognito/latest/developerguide/amazon-cognito-user-pools-using-tokens-with-identity-providers.html</a> i am stuck on the 6 step.</p>
  
  <p>As far as i have seen, i get the modulus and the exponent from Amazon in String and i must build a PublicKey with those, to validate the JWT signature.</p>
  
  <p>I dont know how to build the PublicKey using this two parameters in String.</p>