PdfRpt.Core.Security.SignatureWriter.addSignature C# (CSharp) Method

        private void addSignature(Stream inputPdfStream, PfxData pfxData)
        {
            byte[] buffer;
            using (var outputPdfStream = new MemoryStream())
            {
                using (var stamper = PdfStamper.CreateSignature(new CustomPdfReader(inputPdfStream, pfxData.X509PrivateKeys[0], pfxData.PublicKey), outputPdfStream, '\0', null, SignatureData.CertificateFile.AppendSignature))
                {
                    tryAddSignature(stamper);
                }
                buffer = outputPdfStream.GetBuffer();
            }

            inputPdfStream.Position = 0;
            inputPdfStream.SetLength(0);
            using (var signedStream = new MemoryStream(buffer))
            {
                signedStream.WriteTo(inputPdfStream);
            }
        }