private static string GetSignatureText(X509Certificate x509Certificate, PdfSignatureParameters parameters)
{
Dictionary<string, string> subjectFields = CertificateHelper.GetSubjectFields(x509Certificate);
string surName = subjectFields.Keys.Contains("SURNAME") ? subjectFields["SURNAME"] : string.Empty;
string givenName = subjectFields.Keys.Contains("GIVENNAME") ? subjectFields["GIVENNAME"] : string.Empty;
string signDate = DateTime.Now.ToString("d.M.yyyy");
return parameters.SignatureTemplate
.Replace("{lastname}", UppercaseFirst(surName))
.Replace("{firstname}", UppercaseFirst(givenName))
.Replace("{signdate}", signDate);
}