checking if pdf is password protected using itextsharp

Question

I want to check if a pdf file is password protected or not to view. That is i want to know if the pdf file has user password or not.

I found some help in some forum

Answer 1

  private void CheckPdfProtection(string filePath)
        {
            try
            {
                PdfReader reader = new PdfReader(filePath);
                if (!reader.IsEncrypted()) return;
                if (!PdfEncryptor.IsPrintingAllowed(reader.Permissions))
                    throw new InvalidOperationException("the selected file is print protected and cannot be imported");
                if (!PdfEncryptor.IsModifyContentsAllowed(reader.Permissions))
                    throw new InvalidOperationException("the selected file is write protected and cannot be imported");
            }
            catch (BadPasswordException) { throw new InvalidOperationException("the selected file is password protected and cannot be imported"); }
            catch (BadPdfFormatException) { throw new InvalidDataException("the selected file is having invalid format and cannot be imported"); }
        }