Rust Requires Chilkat v11.7.0+

Find Out Whether a PDF Needs a Password Before Loading It

See more PDF Protection Examples

Demonstrates PreLoadCheck, which examines a PDF file without loading it and without any password. It reports whether the file is encrypted, by which method and algorithm, whether a password is needed to open it, and what its permissions are. An application uses it to decide whether to ask for a password, or which certificate it needs, before calling LoadFile. PreLoadCheckBd does the same for a PDF held in memory. Rust

// 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

// The PDF used in this example is available at encrypted_user_password.pdf

// The PDF used in this example is available at no_copy_permission.pdf

let pdf = chilkat::Pdf::new();
let info = chilkat::JsonObject::new();

// A PDF that is not encrypted.  Nothing but "encrypted" is reported for it.
if pdf.pre_load_check("qa_data/pdf/two_page_memo.pdf", &info).is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

println!("two_page_memo.pdf");
println!("  encrypted: {}", info.bool_of("encrypted"));

// A PDF that needs a password to open.
if pdf.pre_load_check("qa_data/pdf/encrypted_user_password.pdf", &info).is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

println!("encrypted_user_password.pdf");
println!("  encrypted: {}", info.bool_of("encrypted"));
println!("  method: {}", info.string_of("method").unwrap_or_default());
println!("  algorithm: {}", info.string_of("algorithm").unwrap_or_default());
println!("  openPasswordRequired: {}", info.bool_of("openPasswordRequired"));

// A PDF that opens without a password but is restricted.  The permissions are readable without
// any password.
if pdf.pre_load_check("qa_data/pdf/no_copy_permission.pdf", &info).is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

println!("no_copy_permission.pdf");
println!("  encrypted: {}", info.bool_of("encrypted"));
println!("  openPasswordRequired: {}", info.bool_of("openPasswordRequired"));
println!("  may copy: {}", info.bool_of("permissions.copy"));

// The typical use: ask for a password only when one is needed, then load.
if pdf.pre_load_check("qa_data/pdf/encrypted_user_password.pdf", &info).is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

if info.bool_of("openPasswordRequired") {
    // An application would prompt for the password here.
    pdf.set_user_password("secret");
}

if pdf.load_file("qa_data/pdf/encrypted_user_password.pdf").is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

println!("loaded, pages: {}", pdf.num_pages());

// Sample output:

// two_page_memo.pdf
//   encrypted: False
// encrypted_user_password.pdf
//   encrypted: True
//   method: password
//   algorithm: rc4-128
//   openPasswordRequired: True
// no_copy_permission.pdf
//   encrypted: True
//   openPasswordRequired: False
//   may copy: False
// loaded, pages: 1