Add Document TimeStamp (DTS) to a PDF document with Java

Using Qoppa’s PDF library products, jPDProcess and jPDFSecure, it is possible to add a Document Time Stamp (DTS added in PDF 2.0) to a PDF document.

Here is a sample java program that does so.

PDFDocument doc = new PDFDocument(in, null);
 
// Invisible signature field
SignatureField field = doc.getPage(0).addSignatureField("Signature1", new Rectangle2D.Double(0, 0, 0, 0));
 
// pass in credentials for your time stamp server
TimestampServer server = new TimestampServer("http://timestamp.digicert.com", "myuser", "mypwd"); server.setLengthEstimate(8000); 
 
// Create signing information for this timestamp server
SigningInformation signInfo = new SigningInformation(server); 
 
// sign the PDF document
doc.signDocument(field, signInfo); 
 
// save the PDF document
doc.saveDocument(out);

And here is another sample showing how to add a standard digital signature with a time stamp (in this instance a pkcs12 signature) and then a document time stamp to a PDF document. Both signature fields are invisible.

// Load the keystore that contains the digital id to use in signing
FileInputStream pkcs12Stream = new FileInputStream("c:/test/ids/myID.p12");
KeyStore store = KeyStore.getInstance("PKCS12");
store.load(pkcs12Stream, "password".toCharArray());
pkcs12Stream.close();
 
// create a time stamp server object 
// using your own credentials for the server time stamp
TimestampServer server = new TimestampServer("http://timestamp.digicert.com", "myuser", "mypwd");
server.setLengthEstimate(8000);
 
 
// load PDF document 
PDFDocument doc = new PDFDocument(in, null);
 
 
// create an invisible signature field 
SignatureField normal1 = doc.getPage(0).addSignatureField("Signature1", new Rectangle2D.Double(0, 0, 0, 0));
 
// create a standard signature info with a time stamp
SigningInformation signInfo = new SigningInformation(store, "user", "password");
signInfo.setTimestampServer(server);
 
// add standard signature with time stamp
doc.signDocument(normal1, signInfo);
 
// save the PDF 
doc.saveDocument(out);
 
 
// reload the document 
doc = new PDFDocument(out, null);
 
// create a second invisible signature field 
SignatureField timestamp1 = doc.getPage(0).addSignatureField("Signature2", new Rectangle2D.Double(0, 0, 0, 0));
 
// create a document time stamp signature info
// there is no additional signature information needed 
// since this is only a document time stamp signature
SigningInformation tsaInfo = new SigningInformation(server);
 
// sign the PDF document
doc.signDocument(timestamp1, tsaInfo);
 
// save the PDF document
doc.saveDocument(out);
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