Some test text!
To sign an existing approval signature field in a PDF Document:
PDFDoc document = new PDFDoc(inputDocumentPath); // Retrieve the unsigned approval signature field. Field foundApprovalField = document.GetField(inputApprovalFieldName); DigitalSignatureField foundApprovalSignatureDigitalSignatureField = new DigitalSignatureField(foundApprovalField); // (OPTIONAL) Add more information to the signature dictionary. foundApprovalSignatureDigitalSignatureField.SetLocation("Vancouver, BC"); foundApprovalSignatureDigitalSignatureField.SetReason("Document approval."); foundApprovalSignatureDigitalSignatureField.SetContactInfo("www.pdftron.com"); // (OPTIONAL) Add an appearance to the signature field. Image image = Image.Create(document.GetSDFDoc(), inputAppearanceImagePath); SignatureWidget foundApprovalSignatureWidget = new SignatureWidget(foundApprovalField.GetSDFObj()); foundApprovalSignatureWidget.CreateSignatureAppearance(image); // Prepare the signature and signature handler for signing. foundApprovalSignatureDigitalSignatureField.SignOnNextSave(inputPrivateKeyFilePath, inputKeyFilePassword); // The actual approval signing will be done during the following incremental save operation. await document.SaveAsync(inputOutPath, SDFDocSaveOptions.e_incremental);
Digitally sign PDF files
Full code sample which demonstrates using the digital signature API to digitally sign and/or certify PDF documents.
The PDFTron SDK enables approval signatures in PDF documents using a Digital Certificate, in accordance with the latest PDF specification. By leveraging public key infrastructure (PKI) technology, with a certificate issued by a trusted certificate authority (CA), a signer can use a certificate-based digital ID to guarantee the authenticity of a signature. Placement of a digital signature using a certificate can also guarantee that a document was not modified since the signature was placed, ensuring the authenticity of the document.
Above is an example of a document containing a certified signature, guaranteed by a certificate generated by PDFTron.com.
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