public DifiCertificateValidator(Mode mode)
        {
            this.mode = mode;

            try
            {
                var file = new FileInfo(mode.GetValue("security.pki"));
                this.validator = ValidatorLoader.NewInstance().Build(file);
            }
            catch (ValidatorParsingException e)
            {
                throw new PeppolLoadingException("Unable to initiate PKI.", e);
            }
        }