itextpdf.jar is a component in iText 5 Java library to provide core functionalities. iText Java library allows you to generate and manage PDF documents.

The Source Code files are provided at iText GitHub site.

You can compile it to generate your JAR file, using pom.xml as the build configuration file.

The source code of itextpdf-5.5.14.jar is provided below:

⏎ com/itextpdf/text/pdf/PdfEncryptor.java

/*
 *
 * This file is part of the iText (R) project.
    Copyright (c) 1998-2020 iText Group NV
 * Authors: Bruno Lowagie, Paulo Soares, et al.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License version 3
 * as published by the Free Software Foundation with the addition of the
 * following permission added to Section 15 as permitted in Section 7(a):
 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
 * ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
 * OF THIRD PARTY RIGHTS
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Affero General Public License for more details.
 * You should have received a copy of the GNU Affero General Public License
 * along with this program; if not, see http://www.gnu.org/licenses or write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA, 02110-1301 USA, or download the license from the following URL:
 * http://itextpdf.com/terms-of-use/
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU Affero General Public License.
 *
 * In accordance with Section 7(b) of the GNU Affero General Public License,
 * a covered work must retain the producer line in every PDF that is created
 * or manipulated using iText.
 *
 * You can be released from the requirements of the license by purchasing
 * a commercial license. Buying such a license is mandatory as soon as you
 * develop commercial activities involving the iText software without
 * disclosing the source code of your own applications.
 * These activities include: offering paid services to customers as an ASP,
 * serving PDFs on the fly in a web application, shipping iText with a closed
 * source product.
 *
 * For more information, please contact iText Software Corp. at this
 * address: sales@itextpdf.com
 */
package com.itextpdf.text.pdf;

import java.io.IOException;
import java.io.OutputStream;
import java.security.PrivateKey;
import java.util.HashMap;

import org.bouncycastle.cms.CMSException;
import org.bouncycastle.cms.Recipient;
import org.bouncycastle.cms.RecipientInformation;
import org.bouncycastle.cms.jcajce.JceKeyTransEnvelopedRecipient;

import com.itextpdf.text.DocumentException;

/** This class takes any PDF and returns exactly the same but
 * encrypted. All the content, links, outlines, etc, are kept.
 * It is also possible to change the info dictionary.
 */
public final class PdfEncryptor {

    private PdfEncryptor(){
    }

    /** Entry point to encrypt a PDF document. The encryption parameters are the same as in
     * <code>PdfWriter</code>. The userPassword and the
     *  ownerPassword can be null or have zero length. In this case the ownerPassword
     *  is replaced by a random string. The open permissions for the document can be
     *  AllowPrinting, AllowModifyContents, AllowCopy, AllowModifyAnnotations,
     *  AllowFillIn, AllowScreenReaders, AllowAssembly and AllowDegradedPrinting.
     *  The permissions can be combined by ORing them.
     * @param reader the read PDF
     * @param os the output destination
     * @param userPassword the user password. Can be null or empty
     * @param ownerPassword the owner password. Can be null or empty
     * @param permissions the user permissions
     * @param strength128Bits <code>true</code> for 128 bit key length, <code>false</code> for 40 bit key length
     * @throws DocumentException on error
     * @throws IOException on error */
    public static void encrypt(PdfReader reader, OutputStream os, byte userPassword[], byte ownerPassword[], int permissions, boolean strength128Bits) throws DocumentException, IOException {
        PdfStamper stamper = new PdfStamper(reader, os);
        stamper.setEncryption(userPassword, ownerPassword, permissions, strength128Bits);
        stamper.close();
    }

    /** Entry point to encrypt a PDF document. The encryption parameters are the same as in
     * <code>PdfWriter</code>. The userPassword and the
     *  ownerPassword can be null or have zero length. In this case the ownerPassword
     *  is replaced by a random string. The open permissions for the document can be
     *  AllowPrinting, AllowModifyContents, AllowCopy, AllowModifyAnnotations,
     *  AllowFillIn, AllowScreenReaders, AllowAssembly and AllowDegradedPrinting.
     *  The permissions can be combined by ORing them.
     * @param reader the read PDF
     * @param os the output destination
     * @param userPassword the user password. Can be null or empty
     * @param ownerPassword the owner password. Can be null or empty
     * @param permissions the user permissions
     * @param strength128Bits <code>true</code> for 128 bit key length, <code>false</code> for 40 bit key length
     * @param newInfo an optional <CODE>String</CODE> map to add or change
     * the info dictionary. Entries with <CODE>null</CODE>
     * values delete the key in the original info dictionary
     * @throws DocumentException on error
     * @throws IOException on error
     * @since 5.0.1 (generic type in signature)
     */
    public static void encrypt(PdfReader reader, OutputStream os, byte userPassword[], byte ownerPassword[], int permissions, boolean strength128Bits, HashMap<String, String> newInfo) throws DocumentException, IOException {
        PdfStamper stamper = new PdfStamper(reader, os);
        stamper.setEncryption(userPassword, ownerPassword, permissions, strength128Bits);
        stamper.setMoreInfo(newInfo);
        stamper.close();
    }

    /** Entry point to encrypt a PDF document. The encryption parameters are the same as in
     * <code>PdfWriter</code>. The userPassword and the
     *  ownerPassword can be null or have zero length. In this case the ownerPassword
     *  is replaced by a random string. The open permissions for the document can be
     *  AllowPrinting, AllowModifyContents, AllowCopy, AllowModifyAnnotations,
     *  AllowFillIn, AllowScreenReaders, AllowAssembly and AllowDegradedPrinting.
     *  The permissions can be combined by ORing them.
     * @param reader the read PDF
     * @param os the output destination
     * @param strength <code>true</code> for 128 bit key length, <code>false</code> for 40 bit key length
     * @param userPassword the user password. Can be null or empty
     * @param ownerPassword the owner password. Can be null or empty
     * @param permissions the user permissions
     * @throws DocumentException on error
     * @throws IOException on error */
    public static void encrypt(PdfReader reader, OutputStream os, boolean strength, String userPassword, String ownerPassword, int permissions) throws DocumentException, IOException {
        PdfStamper stamper = new PdfStamper(reader, os);
        stamper.setEncryption(strength, userPassword, ownerPassword, permissions);
        stamper.close();
    }

    /** Entry point to encrypt a PDF document. The encryption parameters are the same as in
     * <code>PdfWriter</code>. The userPassword and the
     *  ownerPassword can be null or have zero length. In this case the ownerPassword
     *  is replaced by a random string. The open permissions for the document can be
     *  AllowPrinting, AllowModifyContents, AllowCopy, AllowModifyAnnotations,
     *  AllowFillIn, AllowScreenReaders, AllowAssembly and AllowDegradedPrinting.
     *  The permissions can be combined by ORing them.
     * @param reader the read PDF
     * @param os the output destination
     * @param strength <code>true</code> for 128 bit key length, <code>false</code> for 40 bit key length
     * @param userPassword the user password. Can be null or empty
     * @param ownerPassword the owner password. Can be null or empty
     * @param permissions the user permissions
     * @param newInfo an optional <CODE>String</CODE> map to add or change
     * the info dictionary. Entries with <CODE>null</CODE>
     * values delete the key in the original info dictionary
     * @throws DocumentException on error
     * @throws IOException on error
     * @since 5.0.1 (generic type in signature)
     */
    public static void encrypt(PdfReader reader, OutputStream os, boolean strength, String userPassword, String ownerPassword, int permissions, HashMap<String, String> newInfo) throws DocumentException, IOException {
        PdfStamper stamper = new PdfStamper(reader, os);
        stamper.setEncryption(strength, userPassword, ownerPassword, permissions);
        stamper.setMoreInfo(newInfo);
        stamper.close();
    }


    /** Entry point to encrypt a PDF document. The encryption parameters are the same as in
     * <code>PdfWriter</code>. The userPassword and the
     *  ownerPassword can be null or have zero length. In this case the ownerPassword
     *  is replaced by a random string. The open permissions for the document can be
     *  AllowPrinting, AllowModifyContents, AllowCopy, AllowModifyAnnotations,
     *  AllowFillIn, AllowScreenReaders, AllowAssembly and AllowDegradedPrinting.
     *  The permissions can be combined by ORing them.
     * @param reader the read PDF
     * @param os the output destination
     * @param type the type of encryption. It can be one of STANDARD_ENCRYPTION_40, STANDARD_ENCRYPTION_128 or ENCRYPTION_AES128.
     * Optionally DO_NOT_ENCRYPT_METADATA can be ored to output the metadata in cleartext
     * @param userPassword the user password. Can be null or empty
     * @param ownerPassword the owner password. Can be null or empty
     * @param permissions the user permissions
     * @param newInfo an optional <CODE>String</CODE> map to add or change
     * the info dictionary. Entries with <CODE>null</CODE>
     * values delete the key in the original info dictionary
     * @throws DocumentException on error
     * @throws IOException on error
     * @since 5.0.1 (generic type in signature)
     */
    public static void encrypt(PdfReader reader, OutputStream os, int type, String userPassword, String ownerPassword, int permissions, HashMap<String, String> newInfo) throws DocumentException, IOException {
        PdfStamper stamper = new PdfStamper(reader, os);
        stamper.setEncryption(type, userPassword, ownerPassword, permissions);
        stamper.setMoreInfo(newInfo);
        stamper.close();
    }

    /** Entry point to encrypt a PDF document. The encryption parameters are the same as in
     * <code>PdfWriter</code>. The userPassword and the
     *  ownerPassword can be null or have zero length. In this case the ownerPassword
     *  is replaced by a random string. The open permissions for the document can be
     *  AllowPrinting, AllowModifyContents, AllowCopy, AllowModifyAnnotations,
     *  AllowFillIn, AllowScreenReaders, AllowAssembly and AllowDegradedPrinting.
     *  The permissions can be combined by ORing them.
     * @param reader the read PDF
     * @param os the output destination
     * @param type the type of encryption. It can be one of STANDARD_ENCRYPTION_40, STANDARD_ENCRYPTION_128 or ENCRYPTION_AES128.
     * Optionally DO_NOT_ENCRYPT_METADATA can be ored to output the metadata in cleartext
     * @param userPassword the user password. Can be null or empty
     * @param ownerPassword the owner password. Can be null or empty
     * @param permissions the user permissions
     * values delete the key in the original info dictionary
     * @throws DocumentException on error
     * @throws IOException on error
     */
    public static void encrypt(PdfReader reader, OutputStream os, int type, String userPassword, String ownerPassword, int permissions) throws DocumentException, IOException {
        PdfStamper stamper = new PdfStamper(reader, os);
        stamper.setEncryption(type, userPassword, ownerPassword, permissions);
        stamper.close();
    }

    /**
     * Give you a verbose analysis of the permissions.
     * @param permissions the permissions value of a PDF file
     * @return a String that explains the meaning of the permissions value
     */
    public static String getPermissionsVerbose(int permissions) {
    	StringBuffer buf = new StringBuffer("Allowed:");
    	if ((PdfWriter.ALLOW_PRINTING & permissions) == PdfWriter.ALLOW_PRINTING) buf.append(" Printing");
        if ((PdfWriter.ALLOW_MODIFY_CONTENTS & permissions) == PdfWriter.ALLOW_MODIFY_CONTENTS) buf.append(" Modify contents");
        if ((PdfWriter.ALLOW_COPY & permissions) == PdfWriter.ALLOW_COPY) buf.append(" Copy");
        if ((PdfWriter.ALLOW_MODIFY_ANNOTATIONS & permissions) == PdfWriter.ALLOW_MODIFY_ANNOTATIONS) buf.append(" Modify annotations");
        if ((PdfWriter.ALLOW_FILL_IN & permissions) == PdfWriter.ALLOW_FILL_IN) buf.append(" Fill in");
        if ((PdfWriter.ALLOW_SCREENREADERS & permissions) == PdfWriter.ALLOW_SCREENREADERS) buf.append(" Screen readers");
        if ((PdfWriter.ALLOW_ASSEMBLY & permissions) == PdfWriter.ALLOW_ASSEMBLY) buf.append(" Assembly");
        if ((PdfWriter.ALLOW_DEGRADED_PRINTING & permissions) == PdfWriter.ALLOW_DEGRADED_PRINTING) buf.append(" Degraded printing");
        return buf.toString();
    }

    /**
     * Tells you if printing is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if printing is allowed
     *
     * @since 2.0.7
     */
    public static boolean isPrintingAllowed(int permissions) {
        return (PdfWriter.ALLOW_PRINTING & permissions) == PdfWriter.ALLOW_PRINTING;
    }

    /**
     * Tells you if modifying content is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if modifying content is allowed
     *
     * @since 2.0.7
     */
    public static boolean isModifyContentsAllowed(int permissions) {
        return (PdfWriter.ALLOW_MODIFY_CONTENTS & permissions) == PdfWriter.ALLOW_MODIFY_CONTENTS;
    }

    /**
     * Tells you if copying is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if copying is allowed
     *
     * @since 2.0.7
     */
    public static boolean isCopyAllowed(int permissions) {
        return (PdfWriter.ALLOW_COPY & permissions) == PdfWriter.ALLOW_COPY;
    }

    /**
     * Tells you if modifying annotations is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if modifying annotations is allowed
     *
     * @since 2.0.7
     */
    public static boolean isModifyAnnotationsAllowed(int permissions) {
        return (PdfWriter.ALLOW_MODIFY_ANNOTATIONS & permissions) == PdfWriter.ALLOW_MODIFY_ANNOTATIONS;
    }

    /**
     * Tells you if filling in fields is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if filling in fields is allowed
     *
     * @since 2.0.7
     */
    public static boolean isFillInAllowed(int permissions) {
        return (PdfWriter.ALLOW_FILL_IN & permissions) == PdfWriter.ALLOW_FILL_IN;
    }

    /**
     * Tells you if repurposing for screenreaders is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if repurposing for screenreaders is allowed
     *
     * @since 2.0.7
     */
    public static boolean isScreenReadersAllowed(int permissions) {
        return (PdfWriter.ALLOW_SCREENREADERS & permissions) == PdfWriter.ALLOW_SCREENREADERS;
    }

    /**
     * Tells you if document assembly is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if document assembly is allowed
     *
     * @since 2.0.7
     */
    public static boolean isAssemblyAllowed(int permissions) {
        return (PdfWriter.ALLOW_ASSEMBLY & permissions) == PdfWriter.ALLOW_ASSEMBLY;
    }

    /**
     * Tells you if degraded printing is allowed.
     * @param permissions the permissions value of a PDF file
     * @return	true if degraded printing is allowed
     *
     * @since 2.0.7
     */
    public static boolean isDegradedPrintingAllowed(int permissions) {
        return (PdfWriter.ALLOW_DEGRADED_PRINTING & permissions) == PdfWriter.ALLOW_DEGRADED_PRINTING;
    }

	/**
	 * Gets the content from a recipient.
	 * @param recipientInfo
	 * @param certificateKey
	 * @param certificateKeyProvider
	 * @return
	 * @throws CMSException
	 */
	public static byte[] getContent(RecipientInformation recipientInfo, PrivateKey certificateKey, String certificateKeyProvider) throws CMSException {
	 	Recipient jceKeyTransRecipient = new JceKeyTransEnvelopedRecipient(certificateKey).setProvider(certificateKeyProvider);
		return recipientInfo.getContent(jceKeyTransRecipient);
	}
}

⏎ com/itextpdf/text/pdf/PdfEncryptor.java

Or download all of them as a single archive file:

File name: itextpdf-5.5.14-fyi.zip
File size: 2163839 bytes
Release date: 2009-10-09
Download 

⇒ iText-2.1.6.jar - iText, a JAVA-PDF library

⇐ iText layout.jar Source Code

⇑ Download and Install iText Java Library

⇑⇑ iText for PDF Generation