Encrypting / Decrypting PDFs

These examples were written in answer to questions such as:

Click How to decrypt a PDF document with the owner password?

decryptpdf

JAVA

/*
    This file is part of the iText (R) project.
    Copyright (c) 1998-2023 Apryse Group NV
    Authors: Apryse Software.

    For more information, please contact iText Software at this address:
    sales@itextpdf.com
 */
package com.itextpdf.samples.sandbox.security;

import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfReader;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.kernel.pdf.ReaderProperties;

import java.io.File;

public class DecryptPdf {
    public static final String DEST = "./target/sandbox/security/decrypt_pdf.pdf";
    public static final String SRC = "./src/main/resources/pdfs/hello_encrypted.pdf";

    public static final String OWNER_PASSWORD = "World";

    public static void main(String[] args) throws Exception {
        File file = new File(DEST);
        file.getParentFile().mkdirs();

        new DecryptPdf().manipulatePdf(DEST);
    }

    protected void manipulatePdf(String dest) throws Exception {
        try (PdfDocument document = new PdfDocument(
                new PdfReader(SRC, new ReaderProperties().setPassword(OWNER_PASSWORD.getBytes())),
                new PdfWriter(dest)
        )) {
            byte[] userPasswordBytes = document.getReader().computeUserPassword();

            // The result of user password computation logic can be null in case of
            // AES256 password encryption or non password encryption algorithm
            String userPassword = userPasswordBytes == null ? null : new String(userPasswordBytes);
            System.out.println(userPassword);
        }
    }
}

C#

using System;
using System.IO;
using System.Text;
using iText.Kernel.Pdf;

namespace iText.Samples.Sandbox.Security
{
    public class DecryptPdf
    {
        public static readonly String DEST = "results/sandbox/security/decrypt_pdf.pdf";
        public static readonly String SRC = "../../../resources/pdfs/hello_encrypted.pdf";
        
        public static readonly String OWNER_PASSWORD = "World";

        public static void Main(String[] args)
        {
            FileInfo file = new FileInfo(DEST);
            file.Directory.Create();

            new DecryptPdf().ManipulatePdf(DEST);
        }

        protected void ManipulatePdf(String dest)
        {
            using (PdfDocument document = new PdfDocument(
                new PdfReader(SRC, new ReaderProperties().SetPassword(Encoding.UTF8.GetBytes(OWNER_PASSWORD))),
                new PdfWriter(dest)
            ))
            {
                byte[] computeUserPassword = document.GetReader().ComputeUserPassword();

                // The result of user password computation logic can be null in case of
                // AES256 password encryption or non password encryption algorithm
                String userPassword = computeUserPassword == null ? null : Encoding.UTF8.GetString(computeUserPassword);
                Console.Out.WriteLine(userPassword);
            }
        }
    }
}

decryptpdf2

JAVA

/*
    This file is part of the iText (R) project.
    Copyright (c) 1998-2023 Apryse Group NV
    Authors: Apryse Software.

    For more information, please contact iText Software at this address:
    sales@itextpdf.com
 */
package com.itextpdf.samples.sandbox.security;

import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfReader;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.kernel.pdf.StampingProperties;

import java.io.File;

public class DecryptPdf2 {
    public static final String DEST = "./target/sandbox/security/decrypt_pdf2.pdf";
    public static final String SRC = "./src/main/resources/pdfs/encrypt_pdf_without_user_password.pdf";

    public static void main(String[] args) throws Exception {
        File file = new File(DEST);
        file.getParentFile().mkdirs();

        new DecryptPdf2().manipulatePdf(DEST);
    }

    protected void manipulatePdf(String dest) throws Exception {
        // This is not actually a decrypt example.
        // The old iText5 test shows how to open an encrypted pdf document
        // without user password for modifying with preserving an old owner password
        try (PdfDocument document = new PdfDocument(
                new PdfReader(SRC).setUnethicalReading(true),
                new PdfWriter(dest),
                new StampingProperties().preserveEncryption()
        )) {
            // here we can modify the document
        }
    }
}

C#

using System;
using System.IO;
using iText.Kernel.Pdf;

namespace iText.Samples.Sandbox.Security
{
    public class DecryptPdf2
    {
        public static readonly String DEST = "results/sandbox/security/decrypt_pdf2.pdf";
        public static readonly String SRC = "../../../resources/pdfs/encrypt_pdf_without_user_password.pdf";

        public static void Main(String[] args)
        {
            FileInfo file = new FileInfo(DEST);
            file.Directory.Create();

            new DecryptPdf2().ManipulatePdf(DEST);
        }

        protected void ManipulatePdf(String dest)
        {
            // This is not actually a decrypt example.
            // The old iText5 test shows how to open an encrypted pdf document
            // without user password for modifying with preserving an old owner password
            PdfReader reader = new PdfReader(SRC);
            reader.SetUnethicalReading(true);

            using (PdfDocument document = new PdfDocument(
                new PdfReader(SRC).SetUnethicalReading(true), 
                new PdfWriter(dest),
                new StampingProperties().PreserveEncryption()
            ))
            {
                // here we can modify the document
            }
        }
    }
}

decryptpdf3

JAVA

/*
    This file is part of the iText (R) project.
    Copyright (c) 1998-2023 Apryse Group NV
    Authors: Apryse Software.

    For more information, please contact iText Software at this address:
    sales@itextpdf.com
 */
package com.itextpdf.samples.sandbox.security;

import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfReader;
import com.itextpdf.kernel.pdf.PdfWriter;

import java.io.File;

public class DecryptPdf3 {
    public static final String DEST = "./target/sandbox/security/decrypt_pdf3.pdf";
    public static final String SRC = "./src/main/resources/pdfs/encrypt_pdf_without_user_password.pdf";

    public static void main(String[] args) throws Exception {
        File file = new File(DEST);
        file.getParentFile().mkdirs();

        new DecryptPdf3().manipulatePdf(DEST);
    }

    protected void manipulatePdf(String dest) throws Exception {
        PdfDocument pdfDoc = new PdfDocument(new PdfReader(SRC).setUnethicalReading(true), new PdfWriter(dest));
        pdfDoc.close();
    }
}

C#

using System;
using System.IO;
using iText.Kernel.Pdf;

namespace iText.Samples.Sandbox.Security
{
    public class DecryptPdf3
    {
        public static readonly String DEST = "results/sandbox/security/decrypt_pdf3.pdf";
        public static readonly String SRC = "../../../resources/pdfs/encrypt_pdf_without_user_password.pdf";

        public static void Main(String[] args)
        {
            FileInfo file = new FileInfo(DEST);
            file.Directory.Create();

            new DecryptPdf3().ManipulatePdf(DEST);
        }

        protected void ManipulatePdf(String dest)
        {
            PdfDocument document = new PdfDocument(new PdfReader(SRC).SetUnethicalReading(true), new PdfWriter(dest));
            document.Close();
        }
    }
}

encryptpdf

JAVA

/*
    This file is part of the iText (R) project.
    Copyright (c) 1998-2023 Apryse Group NV
    Authors: Apryse Software.

    For more information, please contact iText Software at this address:
    sales@itextpdf.com
 */
package com.itextpdf.samples.sandbox.security;

import com.itextpdf.kernel.pdf.EncryptionConstants;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfReader;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.kernel.pdf.WriterProperties;

import java.io.File;

public class EncryptPdf {
    public static final String DEST = "./target/sandbox/security/encrypt_pdf.pdf";
    public static final String SRC = "./src/main/resources/pdfs/hello.pdf";

    public static final String OWNER_PASSWORD = "World";
    public static final String USER_PASSWORD = "Hello";

    public static void main(String[] args) throws Exception {
        File file = new File(DEST);
        file.getParentFile().mkdirs();

        new EncryptPdf().manipulatePdf(DEST);
    }

    protected void manipulatePdf(String dest) throws Exception {
        PdfDocument pdfDoc = new PdfDocument(
                new PdfReader(SRC),
                new PdfWriter(dest, new WriterProperties().setStandardEncryption(
                        USER_PASSWORD.getBytes(),
                        OWNER_PASSWORD.getBytes(),
                        EncryptionConstants.ALLOW_PRINTING,
                        EncryptionConstants.ENCRYPTION_AES_128 | EncryptionConstants.DO_NOT_ENCRYPT_METADATA))
        );
        pdfDoc.close();
    }
}

C#

using System;
using System.IO;
using System.Text;
using iText.Kernel.Pdf;

namespace iText.Samples.Sandbox.Security
{
    public class EncryptPdf
    {
        public static readonly String DEST = "results/sandbox/security/encrypt_pdf.pdf";
        public static readonly String SRC = "../../../resources/pdfs/hello.pdf";

        public static readonly String OWNER_PASSWORD = "World";
        public static readonly String USER_PASSWORD = "Hello";

        public static void Main(String[] args)
        {
            FileInfo file = new FileInfo(DEST);
            file.Directory.Create();

            new EncryptPdf().ManipulatePdf(DEST);
        }

        protected void ManipulatePdf(String dest)
        {
            PdfDocument document = new PdfDocument(new PdfReader(SRC), new PdfWriter(dest,
                new WriterProperties().SetStandardEncryption(
                    Encoding.UTF8.GetBytes(USER_PASSWORD),
                    Encoding.UTF8.GetBytes(OWNER_PASSWORD),
                    EncryptionConstants.ALLOW_PRINTING,
                    EncryptionConstants.ENCRYPTION_AES_128 | EncryptionConstants.DO_NOT_ENCRYPT_METADATA
                )));
            document.Close();
        }
    }
}

encryptpdfwithoutuserpassword

JAVA

/*
    This file is part of the iText (R) project.
    Copyright (c) 1998-2023 Apryse Group NV
    Authors: Apryse Software.

    For more information, please contact iText Software at this address:
    sales@itextpdf.com
 */
package com.itextpdf.samples.sandbox.security;

import com.itextpdf.kernel.pdf.EncryptionConstants;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfReader;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.kernel.pdf.WriterProperties;

import java.io.File;

public class EncryptPdfWithoutUserPassword {
    public static final String DEST = "./target/sandbox/security/encrypt_pdf_without_user_password.pdf";
    public static final String SRC = "./src/main/resources/pdfs/hello.pdf";

    public static final String OWNER_PASSWORD = "World";

    public static void main(String[] args) throws Exception {
        File file = new File(DEST);
        file.getParentFile().mkdirs();

        new EncryptPdfWithoutUserPassword().manipulatePdf(DEST);
    }

    protected void manipulatePdf(String dest) throws Exception {
        PdfDocument pdfDoc = new PdfDocument(
                new PdfReader(SRC),
                new PdfWriter(dest, new WriterProperties().setStandardEncryption(
                        // null user password argument is equal to empty string,
                        // this means that no user password required
                        null,
                        OWNER_PASSWORD.getBytes(),
                        EncryptionConstants.ALLOW_PRINTING,
                        EncryptionConstants.ENCRYPTION_AES_128 | EncryptionConstants.DO_NOT_ENCRYPT_METADATA))
        );
        pdfDoc.close();
    }
}

C#

using System;
using System.IO;
using System.Text;
using iText.Kernel.Pdf;

namespace iText.Samples.Sandbox.Security
{
    public class EncryptPdfWithoutUserPassword
    {
        public static readonly String DEST = "results/sandbox/security/encrypt_pdf_without_user_password.pdf";
        public static readonly String SRC = "../../../resources/pdfs/hello.pdf";
        
        public static readonly String OWNER_PASSWORD = "World";

        public static void Main(String[] args)
        {
            FileInfo file = new FileInfo(DEST);
            file.Directory.Create();

            new EncryptPdfWithoutUserPassword().ManipulatePdf(DEST);
        }

        protected void ManipulatePdf(String dest)
        {
            PdfDocument document = new PdfDocument(
                new PdfReader(SRC),
                new PdfWriter(dest,
                    new WriterProperties().SetStandardEncryption(
                        // null user password argument is equal to empty string
                        // this means that no user password required
                        null,
                        Encoding.UTF8.GetBytes(OWNER_PASSWORD),
                        EncryptionConstants.ALLOW_PRINTING,
                        EncryptionConstants.ENCRYPTION_AES_128 | EncryptionConstants.DO_NOT_ENCRYPT_METADATA
                    )));
            document.Close();
        }
    }
}