iTextSharp.text.pdf.PdfReader.GetPageSize C# (CSharp) Метод

        public Rectangle GetPageSize(PdfDictionary page) {
            PdfArray mediaBox = page.GetAsArray(PdfName.MEDIABOX);
            return GetNormalizedRectangle(mediaBox);
        }
        

        public static void SignPdfCert(String SRC, String DEST, String Reason, String Location, String certPassword, String certFile, String llx, String lly, String urx, String ury, int fontSize)
        {
            Pkcs12Store p12ks = new Pkcs12Store();
            FileStream fs = new FileStream(certFile, FileMode.Open);
            p12ks.Load(fs, certPassword.ToCharArray());
            String alias = "";
            foreach (String al in p12ks.Aliases)
            {
                if (p12ks.IsKeyEntry(al) && p12ks.GetKey(al).Key.IsPrivate)
                {
                    alias = al;
                    break;
                }
            }
            AsymmetricKeyParameter pk = p12ks.GetKey(alias).Key;
            ICollection<X509Certificate> chain = new List<X509Certificate>();
            foreach (X509CertificateEntry entry in p12ks.GetCertificateChain(alias))
            {
                chain.Add(entry.Certificate);
            }

            fs.Close();
            //Org.BouncyCastle.X509.X509CertificateParser cp = new Org.BouncyCastle.X509.X509CertificateParser();
            //Org.BouncyCastle.X509.X509Certificate[] chain = new Org.BouncyCastle.X509.X509Certificate[] { cp.ReadCertificate(cert.RawData) };

            IExternalSignature externalSignature = new PrivateKeySignature(pk, DigestAlgorithms.SHA512);
            PdfReader pdfReader = new PdfReader(SRC);
            FileStream signedPdf = new FileStream(DEST, FileMode.Create);  //the output pdf file
            Program.logLine("page size" + pdfReader.GetPageSize(1));

            PdfStamper pdfStamper = PdfStamper.CreateSignature(pdfReader, signedPdf, '\0');
            PdfSignatureAppearance signatureAppearance = pdfStamper.SignatureAppearance;
            //here set signatureAppearance at your will
            signatureAppearance.Reason = Reason;
            signatureAppearance.Location = Location;
            BaseFont bf = BaseFont.CreateFont();
            signatureAppearance.Layer2Font = new Font(bf, fontSize);
            signatureAppearance.SetVisibleSignature(new Rectangle(float.Parse(llx), float.Parse(lly), float.Parse(urx), float.Parse(ury)), 1, "sig");
            //signatureAppearance.SignatureRenderingMode = PdfSignatureAppearance.RenderingMode.DESCRIPTION;
            MakeSignature.SignDetached(signatureAppearance, externalSignature, chain, null, null, null, 0, CryptoStandard.CMS);
            //MakeSignature.SignDetached(signatureAppearance, externalSignature, chain, null, null, null, 0, CryptoStandard.CADES);
        }