/** {@inheritDoc} */
 @Override
 public StatusCode validateCertificate(Cert c) {
   for (Cert certs : trustedCertificates) if (certs.equals(c)) return null;
   for (PublicKey key : trustedPublicKeys) {
     try {
       c.getCertificate().verify(key);
       return null;
     } catch (GeneralSecurityException e) {
       continue;
     }
   }
   return new StatusCode(StatusCodes.Bad_SecurityChecksFailed);
 }
 /**
  * addTrustedSigner.
  *
  * @param signer a {@link org.opcfoundation.ua.transport.security.Cert} object.
  */
 public void addTrustedSigner(Cert signer) {
   addTrustedSignerPublicKey(signer.getCertificate().getPublicKey());
 }