private static Cipher instance() throws GeneralSecurityException {
    if (!FIPS.isCompatible()) {
      throw new GeneralSecurityException("Can not use AES-CMAC in FIPS-mode.");
    }
    return EngineFactory.CIPHER.getInstance("AES/ECB/NoPadding");
  }
An implementation of CMAC following <a href="https://tools.ietf.org/html/rfc4493">RFC 4493</a>.
java_src/src/main/java/com/google/crypto/tink/subtle/PrfAesCmac.java