private byte[] generatePrinterFriendlyVersion(byte[] pdfContent, string verificationCode)
        {
            var client = Util.GetRestPkiClient();

            // The verification code is generated without hyphens to save storage space and avoid copy-and-paste problems. On the PDF generation,
            // we use the "formatted" version, with hyphens (which will later be discarded on the verification page)
            var formattedVerificationCode = Util.FormatVerificationCode(verificationCode);

            // Build the verification link from the constant "VerificationLinkFormat" (see above) and the formatted verification code
            var verificationLink = string.Format(VerificationLinkFormat, formattedVerificationCode);

            // 1. Upload the PDF
            var blob = client.UploadFile(pdfContent);

            // 2. Inspect signatures on the uploaded PDF
            var sigExplorer = new PadesSignatureExplorer(client)
            {
                Validate = true,
                DefaultSignaturePolicyId = StandardPadesSignaturePolicies.Basic,
                SecurityContextId        = Util.GetSecurityContextId(),
            };

            sigExplorer.SetSignatureFile(blob);
            var signature = sigExplorer.Open();

            // 3. Create PDF with verification information from uploaded PDF

            var pdfMarker = new PdfMarker(client);

            pdfMarker.SetFile(blob);

            // Build string with joined names of signers (see method getDisplayName below)
            var signerNames     = Util.JoinStringsPt(signature.Signers.Select(s => getDisplayName(s.Certificate)));
            var allPagesMessage = string.Format("Este documento foi assinado digitalmente por {0}.\nPara verificar a validade das assinaturas acesse {1} em {2} e informe o código {3}", signerNames, VerificationSiteNameWithArticle, VerificationSite, formattedVerificationCode);

            // PdfHelper is a class from the Rest PKI Client "fluent API" that helps to create elements and parameters for the PdfMarker
            var pdf = new PdfHelper();

            // ICP-Brasil logo on bottom-right corner of every page (except on the page which will be created at the end of the document)
            pdfMarker.Marks.Add(
                pdf.Mark()
                .OnAllPages()
                .OnContainer(pdf.Container().Width(1).AnchorRight(1).Height(1).AnchorBottom(1))
                .AddElement(
                    pdf.ImageElement()
                    .WithOpacity(75)
                    .WithImage(Util.GetIcpBrasilLogoContent(), "image/png")
                    )
                );

            // Summary on bottom margin of every page (except on the page which will be created at the end of the document)
            pdfMarker.Marks.Add(
                pdf.Mark()
                .OnAllPages()
                .OnContainer(pdf.Container().Height(2).AnchorBottom().VarWidth().Margins(1.5, 3.5))
                .AddElement(
                    pdf.TextElement()
                    .WithOpacity(75)
                    .AddSection(allPagesMessage)
                    )
                );

            // Summary on right margin of every page (except on the page which will be created at the end of the document),
            // rotated 90 degrees counterclockwise (text goes up)
            pdfMarker.Marks.Add(
                pdf.Mark()
                .OnAllPages()
                .OnContainer(pdf.Container().Width(2).AnchorRight().VarHeight().Margins(1.5, 3.5))
                .AddElement(
                    pdf.TextElement()
                    .Rotate90Counterclockwise()
                    .WithOpacity(75)
                    .AddSection(allPagesMessage)
                    )
                );

            // Create a "manifest" mark on a new page added on the end of the document. We'll add several elements to this mark.
            var manifestMark = pdf.Mark()
                               .OnNewPage()
                               // This mark's container is the whole page with 1-inch margins
                               .OnContainer(pdf.Container().VarWidthAndHeight().Margins(2.54, 2.54));

            // We'll keep track of our "vertical offset" as we add elements to the mark
            double verticalOffset = 0;
            double elementHeight;

            elementHeight = 3;
            manifestMark
            // ICP-Brasil logo on the upper-left corner
            .AddElement(
                pdf.ImageElement()
                .OnContainer(pdf.Container().Height(elementHeight).AnchorTop(verticalOffset).Width(elementHeight /* using elementHeight as width because the image is square */).AnchorLeft())
                .WithImage(Util.GetIcpBrasilLogoContent(), "image/png")
                )
            // QR Code with the verification link on the upper-right corner
            .AddElement(
                pdf.QRCodeElement()
                .OnContainer(pdf.Container().Height(elementHeight).AnchorTop(verticalOffset).Width(elementHeight /* using elementHeight as width because QR Codes are square */).AnchorRight())
                .WithQRCodeData(verificationLink)
                )
            // Header "VERIFICAÇÃO DAS ASSINATURAS" centered between ICP-Brasil logo and QR Code
            .AddElement(
                pdf.TextElement()
                .OnContainer(pdf.Container().Height(elementHeight).AnchorTop(verticalOffset + 0.2).FullWidth())
                .AlignTextCenter()
                .AddSection(pdf.TextSection().WithFontSize(NormalFontSize * 1.6).WithText("VERIFICAÇÃO DAS\nASSINATURAS"))
                );
            verticalOffset += elementHeight;

            // Vertical padding
            verticalOffset += 1.7;

            // Header with verification code
            elementHeight = 2;
            manifestMark.AddElement(
                pdf.TextElement()
                .OnContainer(pdf.Container().Height(elementHeight).AnchorTop(verticalOffset).FullWidth())
                .AlignTextCenter()
                .AddSection(pdf.TextSection().WithFontSize(NormalFontSize * 1.2).WithText(string.Format("Código para verificação: {0}", formattedVerificationCode)))
                );
            verticalOffset += elementHeight;

            // Paragraph saying "this document was signed by the following signers etc" and mentioning the time zone of the date/times below
            elementHeight = 2.5;
            manifestMark.AddElement(
                pdf.TextElement()
                .OnContainer(pdf.Container().Height(elementHeight).AnchorTop(verticalOffset).FullWidth())
                .AddSection(pdf.TextSection().WithFontSize(NormalFontSize).WithText(string.Format("Este documento foi assinado digitalmente pelos seguintes signatários nas datas indicadas ({0}):", TimeZoneDisplayName)))
                );
            verticalOffset += elementHeight;

            // Iterate signers
            foreach (var signer in signature.Signers)
            {
                elementHeight = 1.5;

                manifestMark
                // Green "check" or red "X" icon depending on result of validation for this signer
                .AddElement(
                    pdf.ImageElement()
                    .OnContainer(pdf.Container().Height(0.5).AnchorTop(verticalOffset + 0.2).Width(0.5).AnchorLeft())
                    .WithImage(Util.GetValidationResultIcon(signer.ValidationResults.IsValid), "image/png")
                    )
                // Description of signer (see method getSignerDescription below)
                .AddElement(
                    pdf.TextElement()
                    .OnContainer(pdf.Container().Height(elementHeight).AnchorTop(verticalOffset).VarWidth().Margins(0.8, 0))
                    .AddSection(pdf.TextSection().WithFontSize(NormalFontSize).WithText(getSignerDescription(signer)))
                    );

                verticalOffset += elementHeight;
            }

            // Some vertical padding from last signer
            verticalOffset += 1;

            // Paragraph with link to verification site and citing both the verification code above and the verification link below
            elementHeight = 2.5;
            manifestMark.AddElement(
                pdf.TextElement()
                .OnContainer(pdf.Container().Height(elementHeight).AnchorTop(verticalOffset).FullWidth())
                .AddSection(pdf.TextSection().WithFontSize(NormalFontSize).WithText(string.Format("Para verificar a validade das assinaturas, acesse {0} em ", VerificationSiteNameWithArticle)))
                .AddSection(pdf.TextSection().WithFontSize(NormalFontSize).WithColor(Color.Blue).WithText(VerificationSite))
                .AddSection(pdf.TextSection().WithFontSize(NormalFontSize).WithText(" e informe o código acima ou acesse o link abaixo:"))
                );
            verticalOffset += elementHeight;

            // Verification link
            elementHeight = 1.5;
            manifestMark.AddElement(
                pdf.TextElement()
                .OnContainer(pdf.Container().Height(elementHeight).AnchorTop(verticalOffset).FullWidth())
                .AddSection(pdf.TextSection().WithFontSize(NormalFontSize).WithColor(Color.Blue).WithText(verificationLink))
                .AlignTextCenter()
                );

            // Apply marks
            pdfMarker.Marks.Add(manifestMark);
            var result = pdfMarker.Apply();

            // Return result
            return(result.GetContent());
        }
        private byte[] generatePrinterFriendlyVersion(byte[] pdfContent, string verificationCode)
        {
            // The verification code is generated without hyphens to save storage space and avoid copy-and-paste
            // problems. On the PDF generation, we use the "formatted" version, with hyphens (which will later
            // be discarded on the verification page).
            var formattedVerificationCode = AlphaCode.Format(verificationCode);

            // Build the verification link from the constant "VerificationLinkFormat" (see above) and the
            // formatted verification code.
            var verificationLink = string.Format(VerificationLinkFormat, formattedVerificationCode);

            // 1. Inspect signatures on the PDF.
            var signature = Lacuna.Pki.Pades.PadesSignature.Open(pdfContent);

            // 2. Create PDF with verification information from the signed PDF.
            var pdfMarker = new PdfMarker();

            // Build string with joined names of signers (see method getDisplayName() below).
            var signerNames     = Util.JoinStringsPt(signature.Signers.Select(s => getDisplayName(s.Signer.SigningCertificate)));
            var allPagesMessage = string.Format("This document was digitally signed by {0}.\nTo verify the signatures go to {1} on {2} and inform the code {3}", signerNames, VerificationSiteNameWithArticle, VerificationSite, formattedVerificationCode);

            // ICP-Brasil logo on bottom-right corner of every page (except on the page which will be created at
            // the end of the document).
            pdfMarker.AddMark(new PdfMark()
            {
                PageOption = PdfMarkPageOptions.AllPages,
                Container  = new PadesVisualRectangle()
                {
                    Width  = 1,
                    Right  = 1,
                    Height = 1,
                    Bottom = 1
                },
                Elements = new List <PdfMarkElement>()
                {
                    new PdfMarkImage()
                    {
                        ImageContent = Storage.GetIcpBrasilLogoContent(),
                        Opacity      = 75
                    }
                }
            });

            // Summary on bottom margin of every page (except on the page which will be created at the end of
            // the document).
            pdfMarker.AddMark(new PdfMark()
            {
                PageOption = PdfMarkPageOptions.AllPages,
                Container  = new PadesVisualRectangle()
                {
                    Height = 2,
                    Bottom = 0,
                    Left   = 1.5,
                    Right  = 3.5
                },
                Elements = new List <PdfMarkElement>()
                {
                    new PdfMarkText()
                    {
                        Texts = new List <PdfTextSection>()
                        {
                            new PdfTextSection()
                            {
                                Style = PdfTextStyle.Normal,
                                Text  = allPagesMessage
                            }
                        }
                    }
                }
            });

            // Summary on right margin of every page (except on the page which will be created at the end of the
            // document), rotated 90 degrees counterclockwise (text goes up).
            pdfMarker.AddMark(new PdfMark()
            {
                PageOption = PdfMarkPageOptions.AllPages,
                Container  = new PadesVisualRectangle()
                {
                    Width  = 2,
                    Right  = 0,
                    Top    = 1.5,
                    Bottom = 3.5
                },
                Elements = new List <PdfMarkElement>()
                {
                    new PdfMarkText()
                    {
                        Rotation = PdfMarkRotation.D90,
                        Texts    = new List <PdfTextSection>()
                        {
                            new PdfTextSection()
                            {
                                Style = PdfTextStyle.Normal,
                                Text  = allPagesMessage
                            }
                        }
                    }
                }
            });

            // Create a "manifest" mark on a new page added on the end of the document. We'll add several
            // elements to this marks.
            var manifestMark = new PdfMark()
            {
                PageOption = PdfMarkPageOptions.NewPage,
                // This mark's container is the whole page with 1-inch margins.
                Container = new PadesVisualRectangle()
                {
                    Top    = 2.54,
                    Bottom = 2.54,
                    Right  = 2.54,
                    Left   = 2.54
                }
            };

            // We'll keep track of our "vertical offset" as we add elements to the mark.
            double verticalOffset = 0;
            double elementHeight;

            elementHeight = 3;
            // ICP-Brasil logo on the upper-left corner.
            manifestMark.Elements.Add(new PdfMarkImage()
            {
                RelativeContainer = new PadesVisualRectangle()
                {
                    Height = elementHeight,
                    Top    = verticalOffset,
                    Width  = elementHeight,                    /* Using elemengHeight as width because the image is square. */
                    Left   = 0
                },
                ImageContent = Storage.GetIcpBrasilLogoContent()
            });
            // QR Code with the verification link on the upper-right corner. We will generate a PdfMarkImage from
            // a QR Code generated using the QRCoder library.
            byte[] qrCodeImageContent;
            using (var qrGenerator = new QRCodeGenerator()) {
                using (var qrCodeData = qrGenerator.CreateQrCode(verificationLink, QRCodeGenerator.ECCLevel.M)) {
                    using (var qrCode = new QRCode(qrCodeData)) {
                        var qrCodeBitmap = qrCode.GetGraphic(10, Color.Black, Color.White, false);
                        using (var buffer = new MemoryStream()) {
                            qrCodeBitmap.Save(buffer, ImageFormat.Png);
                            qrCodeImageContent = buffer.ToArray();
                        };
                    }
                }
            }
            manifestMark.Elements.Add(new PdfMarkImage()
            {
                RelativeContainer = new PadesVisualRectangle()
                {
                    Height = elementHeight,
                    Top    = verticalOffset,
                    Width  = elementHeight,                    /* Using elemengHeight as width because the image is square. */
                    Right  = 0
                },
                ImageContent = qrCodeImageContent
            });
            // Header "SIGNATURES VERIFICATION" centered between ICP-Brasil logo and QR Code.
            manifestMark.Elements.Add(new PdfMarkText()
            {
                RelativeContainer = new PadesVisualRectangle()
                {
                    Height = elementHeight,
                    Top    = verticalOffset + 0.2,
                    Right  = 0,
                    Left   = 0
                },
                Align = PadesHorizontalAlign.Center,
                Texts = new List <PdfTextSection>()
                {
                    new PdfTextSection()
                    {
                        Style    = PdfTextStyle.Normal,
                        FontSize = NormalFontSize * 1.6,
                        Text     = "SIGNATURES\nVERIFICATION"
                    }
                }
            });
            verticalOffset += elementHeight;

            // Verifical padding.
            verticalOffset += 1.7;

            // Header with verification code.
            elementHeight = 2;
            manifestMark.Elements.Add(new PdfMarkText()
            {
                RelativeContainer = new PadesVisualRectangle()
                {
                    Height = elementHeight,
                    Top    = verticalOffset,
                    Right  = 0,
                    Left   = 0
                },
                Align = PadesHorizontalAlign.Center,
                Texts = new List <PdfTextSection>()
                {
                    new PdfTextSection()
                    {
                        Style    = PdfTextStyle.Normal,
                        FontSize = NormalFontSize * 1.2,
                        Text     = string.Format("Verification Code: {0}", formattedVerificationCode)
                    }
                }
            });
            verticalOffset += elementHeight;

            // Paragraph saying "this document was signed by the following signer etc" and mentioning the time zone of the
            // date/times below.
            elementHeight = 2.5;
            manifestMark.Elements.Add(new PdfMarkText()
            {
                RelativeContainer = new PadesVisualRectangle()
                {
                    Height = elementHeight,
                    Top    = verticalOffset,
                    Left   = 0,
                    Right  = 0
                },
                Texts = new List <PdfTextSection>()
                {
                    new PdfTextSection()
                    {
                        Style    = PdfTextStyle.Normal,
                        FontSize = NormalFontSize,
                        Text     = string.Format("This document was digitally signed by the following signers on the indicated dates ({0}):", TimeZoneDisplayName)
                    }
                }
            });
            verticalOffset += elementHeight;

            // Iterate signers.
            foreach (var signer in signature.Signers)
            {
                elementHeight = 1.5;

                // Validate signature based on the PAdES Basic policy.
                var policyMapper      = PadesPoliciesForGeneration.GetPadesBasic(Util.GetTrustArbitrator());
                var validationResults = signature.ValidateSignature(signer, policyMapper);

                // Green "check" or red "X" icon depending on result of validation for this signer.
                manifestMark.Elements.Add(new PdfMarkImage()
                {
                    RelativeContainer = new PadesVisualRectangle()
                    {
                        Height = 0.5,
                        Top    = verticalOffset + 0.2,
                        Width  = 0.5,
                        Left   = 0
                    },
                    ImageContent = Storage.GetValidationResultIcon(validationResults.IsValid)
                });
                // Description of signer (see method getSignerDescription() below).
                manifestMark.Elements.Add(new PdfMarkText()
                {
                    RelativeContainer = new PadesVisualRectangle()
                    {
                        Height = elementHeight,
                        Top    = verticalOffset,
                        Left   = 0.8,
                        Right  = 0
                    },
                    Texts = new List <PdfTextSection>()
                    {
                        new PdfTextSection()
                        {
                            Style    = PdfTextStyle.Normal,
                            FontSize = NormalFontSize,
                            Text     = getSignerDescription(signer)
                        }
                    }
                });

                verticalOffset += elementHeight;
            }

            // Some vertical padding from last signer.
            verticalOffset += 1;

            // Paragraph with link to veritifcation site and citing both the verification code above and the
            // verification link below.
            elementHeight = 2.5;
            manifestMark.Elements.Add(new PdfMarkText()
            {
                RelativeContainer = new PadesVisualRectangle()
                {
                    Height = elementHeight,
                    Top    = verticalOffset,
                    Right  = 0,
                    Left   = 0
                },
                Texts = new List <PdfTextSection>()
                {
                    new PdfTextSection()
                    {
                        Style    = PdfTextStyle.Normal,
                        FontSize = NormalFontSize,
                        Text     = string.Format("To verify the signatures, go to {0} on ", VerificationSiteNameWithArticle)
                    },
                    new PdfTextSection()
                    {
                        Color    = Color.Blue,
                        Style    = PdfTextStyle.Normal,
                        FontSize = NormalFontSize,
                        Text     = VerificationSite
                    },
                    new PdfTextSection()
                    {
                        Style    = PdfTextStyle.Normal,
                        FontSize = NormalFontSize,
                        Text     = " and inform the code above or follow the link below:"
                    }
                }
            });
            verticalOffset += elementHeight;

            // Verification link.
            elementHeight = 1.5;
            manifestMark.Elements.Add(new PdfMarkText()
            {
                RelativeContainer = new PadesVisualRectangle()
                {
                    Height = elementHeight,
                    Top    = verticalOffset,
                    Right  = 0,
                    Left   = 0
                },
                Align = PadesHorizontalAlign.Center,
                Texts = new List <PdfTextSection>()
                {
                    new PdfTextSection()
                    {
                        Color    = Color.Blue,
                        Style    = PdfTextStyle.Normal,
                        FontSize = NormalFontSize,
                        Text     = verificationLink
                    }
                }
            });
            pdfMarker.AddMark(manifestMark);

            // Prevent from throwing exception when the file to be marked already have a signature (default: true).
            pdfMarker.ThrowIfSignedPdf = false;
            // Note: Before applying the marks, all signature from the signed file will be removed.

            // Apply marks and return the printer-friendly PDF's content.
            byte[] pfvContent = pdfMarker.WriteMarks(pdfContent);
            return(pfvContent);
        }