JavaScript Requires Chilkat v11.7.0+

Password-Protect a PDF with AES-256 Encryption

See more PDF Protection Examples

Demonstrates the simplest way to encrypt a PDF so that it needs a password to open. The passwords come from the UserPassword and OwnerPassword properties, and Protection with the encrypt operation and an empty JSON uses the defaults: AES-256, everything encrypted, every permission granted. Protection only records the security the PDF will be saved with. Nothing is encrypted until WriteFile is called. JavaScript

var success = false;

//  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

var pdf = new CkPdf();
success = pdf.LoadFile("qa_data/pdf/two_page_memo.pdf");
if (success == false) {
    console.log(pdf.LastErrorText);
    return;
}

//  The passwords are taken from these two properties at the time Protection is called.
//  The user password opens the PDF.  The owner password opens it too, and is the one needed
//  later to change or remove the protection.
pdf.UserPassword = "user-secret";
pdf.OwnerPassword = "owner-secret";

//  An empty JSON asks for the defaults: AES-256, everything encrypted, every permission granted.
var json = new CkJsonObject();
var jsonOut = new CkJsonObject();
success = pdf.Protection("encrypt",json,jsonOut);
if (success == false) {
    console.log(pdf.LastErrorText);
    return;
}

//  Nothing has been encrypted yet.  "pending" describes the security the PDF will be saved with.
console.log("algorithm: " + jsonOut.StringOf("pending.algorithm"));
console.log("PDF version: " + jsonOut.StringOf("pending.pdfVersion"));
console.log("password needed to open: " + jsonOut.BoolOf("pending.userPasswordRequired"));

//  Writing the file applies it.
success = pdf.WriteFile("qa_output/memo_encrypted.pdf");
if (success == false) {
    console.log(pdf.LastErrorText);
    return;
}

//  PreLoadCheck reports a file's encryption without loading it, and needs no password.
var checker = new CkPdf();
var info = new CkJsonObject();
success = checker.PreLoadCheck("qa_output/memo_encrypted.pdf",info);
if (success == false) {
    console.log(checker.LastErrorText);
    return;
}

console.log("encrypted: " + info.BoolOf("encrypted"));
console.log("openPasswordRequired: " + info.BoolOf("openPasswordRequired"));

//  With the password, the PDF opens normally.
var reader = new CkPdf();
reader.UserPassword = "user-secret";
success = reader.LoadFile("qa_output/memo_encrypted.pdf");
if (success == false) {
    console.log(reader.LastErrorText);
    return;
}

console.log("pages: " + reader.NumPages);

//  Sample output:

//  algorithm: aes-256
//  PDF version: 1.7
//  password needed to open: True
//  encrypted: True
//  openPasswordRequired: True
//  pages: 2