.NET Core C#

Add a Document Timestamp Signature to an already-signed PDF

See more PDF Signatures Examples

Demonstrates how to add a document timestamp signature to an already-signed PDF.

Note: This example requires Chilkat v9.5.0.99 or greater.

.NET Core C#

bool success = false;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

Chilkat.Pdf pdf = new Chilkat.Pdf();

// Load the PDF that has already been signed.
success = pdf.LoadFile("qa_data/pdf/helloWorld_signed.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Chilkat.JsonObject json = new Chilkat.JsonObject();

json.UpdateBool("invisibleSignature",true);
json.UpdateString("subFilter","/ETSI.RFC3161");

json.UpdateBool("timestampToken.enabled",true);

// In this example, we'll use a free TSA server (timestamp.digicert.com), but you may want to use your own timestamp authority server.
json.UpdateString("timestampToken.tsaUrl","http://timestamp.digicert.com");

// If the timestamp server requires a username/password, do the following.  Otherwise omit the following few lines of code.
json.UpdateString("timestampToken.tsaUsername","the_tsa_username");
json.UpdateString("timestampToken.tsaPassword","the_tsa_password");

// When requesting the timestamp token, ask the server to include its certificate in the timestamp token response.
// This allows for the timestamp server's certificate to be included in the LTV validation (i.e. if the timestamp server
// has an OCSP URL, then Chilkat will also do the OCSP request for the timestamp server's certificate.)
json.UpdateBool("timestampToken.requestTsaCert",true);

success = pdf.SignPdf(json,"c:/temp/qa_output/helloWorld_signed_2.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Debug.WriteLine("Successfully added a Document Timestamp Signature to the PDF");