code: @Nullable
    public static byte [] convertCertificateStringToByteArray (@Nullable final String sCertificate)
    {
      // Remove prefix/suffix
      final String sPlainCert = getWithoutPEMHeader (sCertificate);
      if (StringHelper.hasNoText (sPlainCert))
        return null;
  
      // The remaining string is supposed to be Base64 encoded -> decode
      return Base64.safeDecode (sPlainCert);
    }
docs: Convert the passed X.509 certificate string to a byte array.
  
  @param sCertificate
  The original certificate string. May be <code>null</code> or empty.
  @return <code>null</code> if the passed string is <code>null</code> or
  empty or an invalid Base64 string