(Java) Sign PDF with Timestamp from TSA (Timestamp Server Authority)

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This example demonstrates how to a sign a PDF that is both long-term validation (LTV) enabled and includes a validating timestamp from a TSA (Timestamp Server Authority).

Note: This example requires Chilkat v9.5.0.85 or greater.

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import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkPdf pdf = new CkPdf();

    // Load a PDF to be signed.
    // The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
    boolean success = pdf.LoadFile("qa_data/pdf/hello.pdf");
    if (success == false) {
        System.out.println(pdf.lastErrorText());
        return;
        }

    // Options for signing are specified in JSON.
    CkJsonObject json = new CkJsonObject();

    // In most cases, the signingCertificateV2 and signingTime attributes are required.
    json.UpdateInt("signingCertificateV2",1);
    json.UpdateInt("signingTime",1);

    // Tell Chilkat to create an LTV-enabled (long term validation) signature.
    // See PDF Long-Term Validation (LTV) Signature Example for more detailed comments about "ltvOcsp".
    json.UpdateBool("ltvOcsp",true);

    // Tell Chilkat to request a timestamp from a TSA server and include the timestamp token (1.2.840.113549.1.9.16.2.14)
    // in the CMS signature's authentication attributes
    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);

    // Define the appearance of the signature.
    json.UpdateInt("page",1);
    json.UpdateString("appearance.y","top");
    json.UpdateString("appearance.x","left");
    json.UpdateString("appearance.fontScale","10.0");
    json.UpdateString("appearance.text[0]","Digitally signed by: cert_cn");
    json.UpdateString("appearance.text[1]","current_dt");
    json.UpdateString("appearance.text[2]","This is an LTV-enabled signature with a TSA timestamp.");

    // Load the signing certificate. (Use your own certificate.)
    CkCert cert = new CkCert();
    success = cert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","pfxPassword");
    if (success == false) {
        System.out.println(cert.lastErrorText());
        return;
        }

    // Tell the pdf object to use the certificate for signing.
    success = pdf.SetSigningCert(cert);
    if (success == false) {
        System.out.println(pdf.lastErrorText());
        return;
        }

    success = pdf.SignPdf(json,"qa_output/hello_ltv_signed_with_timestamp.pdf");
    if (success == false) {
        System.out.println(pdf.lastErrorText());
        return;
        }

    System.out.println("The PDF has been successfully cryptographically signed with TSA timestamp and long-term validation.");

    // If you open the Signature Panel in Adobe Acrobat, it will indicate that the signature is LTV enabled
    // and contains an embedded timestamp:
    
  }
}