@Override
 protected void prompt(LoginController controller) throws LoginCanceledException {
   // Configure with the same host as S3 to get the same credentials from the keychain.
   controller.check(
       new Host(Protocol.S3_SSL, Protocol.S3_SSL.getDefaultHostname(), host.getCredentials()),
       this.getName(),
       null,
       true,
       false,
       false);
 }