Digital Signatures
A digital signature turns a PDF document into evidence: of who signed it, and that it's unchanged since. TX Text Control .NET for WPF creates such signatures when it saves a document as PDF or PDF/A, for the whole document or for single signature fields, with a certificate from a .pfx file or the user's Windows certificate store. Developers who add signing to a WPF application find the concepts, the handling of certificates, visible signatures, several signers and trusted timestamps in the pages below.
The quickest start is Digitally Sign a PDF in Getting Started: a test certificate and a signed document from a button in MainWindow.xaml.
How Signing Works in TX Text Control
A DigitalSignature wraps an X.509 certificate, and the SaveSettings of a PDF or PDF/A save apply it: to the whole document, invisibly, or to named signature fields, each with its own certificate and image. The Overview explains both ways and the classes that take part.
Find the Right Page
| If you want to | Read |
|---|---|
| Know what a signature proves, how electronic and digital signatures differ and which classes take part | Overview |
| Sign the editor's document or a merged document, sign into memory, handle errors and verify signatures in code | Signing PDF Documents |
| Load certificates from .pfx files or the Windows certificate store, let users choose one and check it | Certificates |
| Sign signature fields, set their images and generate a signature appearance | Signature Fields and Signature Appearance |
| Sign one document for several people or with several certificates | Multiple Signatures |
| Add trusted timestamps, cope with unavailable time servers and create PAdES-T signatures | Timestamp Configuration |
Recommended Order
- Overview: concepts and classes.
- Certificates: the certificate to develop with and your users' certificates.
- Signing PDF Documents for an invisible signature, or Signature Fields and Signature Appearance for visible ones.
- Timestamp Configuration: signatures that stay verifiable after the certificate expires.