public static string SignFile(string fileName, PdfSignatureParameters parameters, IDigitalSignatureCertificateSelector certificateSelector) { if (string.IsNullOrWhiteSpace(fileName)) { throw new ArgumentException("Filename must be given", nameof(fileName)); } if (!File.Exists(fileName)) { throw new ArgumentException($"File {fileName} not found."); } if (parameters == null) { throw new ArgumentNullException(nameof(parameters)); } if (certificateSelector == null) { throw new ArgumentNullException(nameof(certificateSelector)); } string tempPath = string.Empty; try { tempPath = GetTempPath(parameters.TempFolderPath); string targetFilePath = GetTargetFilePath(parameters.TempFolderPath, parameters.TargetFilePath); var signingCertificates = CertificateHelper.GetSigningCertificates(certificateSelector); // Two clients for checking certificate revocation // * Online Certificate Status Protocol (OCSP) client // * Certificate Revocation Lists (CRL) client with online checking // Certificate will be checked when the signature is made OcspClientBouncyCastle oscpClient = new OcspClientBouncyCastle(null); List<ICrlClient> clrClients = new List<ICrlClient> { new CrlClientOnline(signingCertificates.FinalChain) }; using (FileStream targetFileStream = new FileStream(targetFilePath, FileMode.Create)) using (PdfReader reader = new PdfReader(fileName)) { PdfStamper stamper = PdfStamper.CreateSignature(reader, targetFileStream, '0', tempPath, true); PdfSignatureAppearance appearance = GetPdfSignatureAppearance(signingCertificates, stamper, reader, parameters); CreateSignature(signingCertificates, appearance, clrClients, oscpClient); } return targetFilePath; } finally { if (!string.IsNullOrWhiteSpace(tempPath) && File.Exists(tempPath)) { File.Delete(tempPath); } } }
private static Rectangle GetSignatureLocation(Rectangle cropBox, PdfSignatureParameters parameters) { return new Rectangle(cropBox.GetLeft(parameters.SignatureLeftMargin), cropBox.GetTop(parameters.SignatureYLocation + parameters.SignatureHeight), cropBox.Width - parameters.SignatureRightMargin, cropBox.GetTop(parameters.SignatureYLocation)); }
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); }
private static PdfSignatureAppearance GetPdfSignatureAppearance(SigningCertificates signingCertificates, PdfStamper stamper, PdfReader reader, PdfSignatureParameters parameters) { PdfSignatureAppearance appearance = stamper.SignatureAppearance; appearance.Reason = ""; appearance.LocationCaption = ""; appearance.Location = ""; appearance.Layer4Text = ""; appearance.Layer2Text = GetSignatureText(signingCertificates.X509Certificate, parameters); appearance.Acro6Layers = true; Rectangle cropBox = reader.GetCropBox(parameters.SignaturePageNumber); Rectangle rectangle = GetSignatureLocation(cropBox, parameters); appearance.SetVisibleSignature(rectangle, parameters.SignaturePageNumber, parameters.SignatureName); return appearance; }