private String getSign(String input) {
    try {
      MessageDigest md = MessageDigest.getInstance("SHA-256");
      md.update(input.getBytes());
      md.update(signatureSecret);
      byte[] digest = md.digest();
      return Base64.getEncoder().encodeToString(digest);
    } catch (NoSuchAlgorithmException ex) {
      throw new RuntimeException(ex);
    }
  }
A token is generated when the SAML assertion is successfully validated. This Token
is passed back to the client (Jdbc/ODBC Driver) via the browser. This token is
presented by the subsequent http request as a bearer token.
service/src/java/org/apache/hive/service/auth/saml/HiveSamlAuthTokenGenerator.java