general/aes256_unicode_password

 * $Id: aes256_unicode_password.java,v 1.4 2013/02/20 10:35:45 stm Exp $

 *

 * Demonstrate AES-256 encryption and Unicode passwords.

 *

 * The file can only be opened with Acrobat X and later.

 *

 * Required software: PDFlib/PDFlib+PDI/PPS 9

 * Required data: Norasi font

 */

package com.pdflib.cookbook.pdflib.general;

import com.pdflib.pdflib;

import com.pdflib.PDFlibException;

public class aes256_unicode_password {

    public static void main(String argv[]) {

        final String outfile = "aes256_unicode_password.pdf";

        final String title = "AES-256 encryption and Unicode passwords";

        /* This is where the data files are. Adjust as necessary. */

        final String searchpath = "../input";

        pdflib p = null;

        try {

            p = new pdflib();

            /* This means we must check return values of load_font() etc. */

            p.set_option("errorpolicy=return");

            p.set_option("searchpath={" + searchpath + "}");

            /*

             * The password demonstrates some features of Unicode passwords:

             *

             * - Characters outside the normal 8-bit character range (THAI

             *   CHARACTER KO KHAI and THAI CHARACTER KHO KAI)

             *   

             * - Normalization of Unicode passwords (LATIN SMALL LIGATURE FF

             *   and LATIN SMALL LIGATURE FI are normalized to "ff" and "fi")

             */

            final String thai_letters = "\u0E01\uu0E02";

            final String ligatures = "\uFB00 \uFB01";

            final String normalized_ligatures ="ff fi";

            final String password = thai_letters + " " + ligatures;

            final String normalized_password = thai_letters + " "

                                        + normalized_ligatures;

            /*

             * To get AES-256 encryption the PDF version must be set to

             * PDF 1.7 extension level 8.

             */

            final String optlist = "compatibility=1.7ext8 "

                    + "masterpassword={" + password + "}";

            if (p.begin_document(outfile, optlist) == -1)

                throw new Exception("Error: " + p.get_errmsg());

            p.set_info("Creator", "PDFlib Cookbook");

            p.set_info("Title", title + " $Revision: 1.4 $");

            p.begin_page_ext(595, 842, "");

            final int font = p.load_font("Norasi", "unicode", "embedding");

            if (font == -1)

                throw new Exception("Error: " + p.get_errmsg());

            p.fit_textline("AES-256 encryption and Unicode passwords", 50, 700,

                "font=" + font + " fontsize=24");

            final String text =

                "This document produced by PDFlib is AES-256-encrypted. It "

                + "can only be opened by Acrobat X and later.\n\n"

                + "The master password of this document is:\n\n"

                + password

                + "\n\nUse cut&paste to enter the password into the Acrobat "

                + "prompt for changing the security settings of the document.\n\n"

                + "Because the password is normalized, it can also be "

                + "entered like this (note the decomposed ligatures):\n\n"

                + normalized_password;

            final int tf = p.add_textflow(-1, text,

                "fontname=Norasi fontsize=18 encoding=unicode");

            if (tf == -1)

                throw new Exception("Error: " + p.get_errmsg());

            p.fit_textflow(tf, 50, 50, 500, 650, "");

            p.end_page_ext("");

            p.end_document("");

        }

        catch (PDFlibException e) {

            System.err.print("PDFlib exception occurred:\n");

            System.err.print("[" + e.get_errnum() + "] " + e.get_apiname()

                + ": " + e.get_errmsg() + "\n");

        }

        catch (Exception e) {

            System.err.println(e.getMessage());

        }

        finally {

            if (p != null) {

                p.delete();

            }

        }

    }

}