Java Requires Chilkat v11.7.0+

Encrypt a PDF for a Certificate Instead of a Password

See more PDF Protection Examples

Demonstrates certificate security, where a PDF is encrypted for one or more recipients and each opens it with their own certificate and private key. No password is involved. Only the public certificate of a recipient is needed to encrypt. Each recipient has its own permissions, and the changeSecurity permission gives a recipient owner rights. PreLoadCheck tells an application that a file is certificate-encrypted and which certificates can open it. A PDF that cannot be opened, because no matching certificate and private key were provided, fails to load. Chilkat2 Java

import com.chilkatsoft.chilkat2.Cert;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.JsonObject;
import com.chilkatsoft.chilkat2.Pdf;

public class ChilkatExample {

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

        // The PDF used in this example is available at two_page_memo.pdf

        // The recipient's certificate.  Only the public certificate is needed to encrypt.
        Cert recipient = new Cert();
        try {
            recipient.loadFromFile("qa_data/certs/recipient.cer");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        Pdf pdf = new Pdf();
        try {
            pdf.loadFile("qa_data/pdf/two_page_memo.pdf");

            // Call AddEncryptCert once for each recipient.
            pdf.addEncryptCert(recipient);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // recipientPermissions[0] belongs to the first certificate added.  changeSecurity gives that
        // recipient owner rights, so the file can be managed later.
        JsonObject json = new JsonObject();
        json.updateString("method", "certificate");
        json.updateBool("recipientPermissions[0].changeSecurity", true);

        JsonObject jsonOut = new JsonObject();
        try {
            pdf.protection("encrypt", json, jsonOut);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("method: " + jsonOut.stringOf("pending.method"));
        System.out.println("algorithm: " + jsonOut.stringOf("pending.algorithm"));
        System.out.println("recipients: " + jsonOut.sizeOfArray("pending.recipients"));

        try {
            pdf.writeFile("qa_output/memo_for_recipient.pdf");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // PreLoadCheck says how the file is protected, without loading it.
        Pdf reader = new Pdf();
        JsonObject info = new JsonObject();
        try {
            reader.preLoadCheck("qa_output/memo_for_recipient.pdf", info);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("saved file, method: " + info.stringOf("method"));
        System.out.println("saved file, recipients: " + info.sizeOfArray("recipients"));

        // The recipient opens it with the certificate and its private key, here from a .pfx file.
        // (On Windows, a certificate that is installed in the Windows certificate store with its private
        // key is found automatically when the PDF is loaded, and SetDecryptCert is not needed for it.)
        Cert myCert = new Cert();
        try {
            myCert.loadPfxFile("qa_data/pfx/recipient.pfx", "pfx-password");

            reader.setDecryptCert(myCert);

            reader.loadFile("qa_output/memo_for_recipient.pdf");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        JsonObject empty = new JsonObject();
        JsonObject loadedInfo = new JsonObject();
        try {
            reader.protection("getInfo", empty, loadedInfo);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("opened with: " + loadedInfo.stringOf("loaded.openedWith"));
        System.out.println("pages: " + reader.getNumPages());

        // Sample output:

        // method: certificate
        // algorithm: aes-256
        // recipients: 1
        // saved file, method: certificate
        // saved file, recipients: 1
        // opened with: certificate
        // pages: 2
    }
}