Java Requires Chilkat v11.7.0+

Choose the PDF Encryption Algorithm: AES-256, AES-128 or RC4

See more PDF Protection Examples

Demonstrates the algorithmChoice option of the encrypt operation. aes-256 is the default and the one to use unless an older reader must open the file. aes-128 is for readers that predate AES-256. rc4-128 and rc4-40 are broken ciphers kept only for very old readers. Each algorithm needs a minimum PDF version, and the file header is raised to it when the PDF is saved, never lowered. A PDF saved with RC4 is written with a classic cross-reference table so that those old readers can parse it. Chilkat2 Java

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

        JsonObject json = new JsonObject();
        JsonObject jsonOut = new JsonObject();
        JsonObject info = new JsonObject();

        // AES-256, the default.  Saved as PDF 1.7 with Adobe extension level 8.
        Pdf pdf1 = new Pdf();
        try {
            pdf1.loadFile("qa_data/pdf/two_page_memo.pdf");

            pdf1.setUserPassword("user-secret");
            pdf1.setOwnerPassword("owner-secret");
            json.updateString("algorithmChoice", "aes-256");
            pdf1.protection("encrypt", json, jsonOut);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("aes-256 will be saved as PDF " + jsonOut.stringOf("pending.pdfVersion") + ", Adobe extension level " + jsonOut.intOf("pending.adobeExtensionLevel"));
        try {
            pdf1.writeFile("qa_output/memo_aes256.pdf");

            pdf1.preLoadCheck("qa_output/memo_aes256.pdf", info);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("  saved file: " + info.stringOf("algorithm") + ", PDF " + info.stringOf("pdfVersion"));

        // AES-128, for readers that predate AES-256.  Saved as PDF 1.6.
        Pdf pdf2 = new Pdf();
        try {
            pdf2.loadFile("qa_data/pdf/two_page_memo.pdf");

            pdf2.setUserPassword("user-secret");
            pdf2.setOwnerPassword("owner-secret");
            json.updateString("algorithmChoice", "aes-128");
            pdf2.protection("encrypt", json, jsonOut);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("aes-128 will be saved as PDF " + jsonOut.stringOf("pending.pdfVersion"));
        try {
            pdf2.writeFile("qa_output/memo_aes128.pdf");

            pdf2.preLoadCheck("qa_output/memo_aes128.pdf", info);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("  saved file: " + info.stringOf("algorithm") + ", PDF " + info.stringOf("pdfVersion"));

        // RC4-128, a broken cipher, only for readers too old for AES.  Saved as PDF 1.4.
        Pdf pdf3 = new Pdf();
        try {
            pdf3.loadFile("qa_data/pdf/two_page_memo.pdf");

            pdf3.setUserPassword("user-secret");
            pdf3.setOwnerPassword("owner-secret");
            json.updateString("algorithmChoice", "rc4-128");
            pdf3.protection("encrypt", json, jsonOut);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("rc4-128 will be saved as PDF " + jsonOut.stringOf("pending.pdfVersion"));
        try {
            pdf3.writeFile("qa_output/memo_rc4_128.pdf");

            pdf3.preLoadCheck("qa_output/memo_rc4_128.pdf", info);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("  saved file: " + info.stringOf("algorithm") + ", PDF " + info.stringOf("pdfVersion"));

        // Sample output:

        // aes-256 will be saved as PDF 1.7, Adobe extension level 8
        //   saved file: aes-256, PDF 1.7
        // aes-128 will be saved as PDF 1.6
        //   saved file: aes-128, PDF 1.6
        // rc4-128 will be saved as PDF 1.4
        //   saved file: rc4-128, PDF 1.4
    }
}