Swift 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. Swift

func chilkatTest() {
    var success: Bool = 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

    //  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 = CkoPdf()!
    let info = CkoJsonObject()!

    //  A PDF that is not encrypted.  Nothing but "encrypted" is reported for it.
    success = pdf.preLoadCheck(path: "qa_data/pdf/two_page_memo.pdf", jsonOut: info)
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    print("two_page_memo.pdf")
    print("  encrypted: \(info.bool(of: "encrypted"))")

    //  A PDF that needs a password to open.
    success = pdf.preLoadCheck(path: "qa_data/pdf/encrypted_user_password.pdf", jsonOut: info)
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    print("encrypted_user_password.pdf")
    print("  encrypted: \(info.bool(of: "encrypted"))")
    print("  method: \(info.string(of: "method")!)")
    print("  algorithm: \(info.string(of: "algorithm")!)")
    print("  openPasswordRequired: \(info.bool(of: "openPasswordRequired"))")

    //  A PDF that opens without a password but is restricted.  The permissions are readable without
    //  any password.
    success = pdf.preLoadCheck(path: "qa_data/pdf/no_copy_permission.pdf", jsonOut: info)
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    print("no_copy_permission.pdf")
    print("  encrypted: \(info.bool(of: "encrypted"))")
    print("  openPasswordRequired: \(info.bool(of: "openPasswordRequired"))")
    print("  may copy: \(info.bool(of: "permissions.copy"))")

    //  The typical use: ask for a password only when one is needed, then load.
    success = pdf.preLoadCheck(path: "qa_data/pdf/encrypted_user_password.pdf", jsonOut: info)
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    if info.bool(of: "openPasswordRequired") == true {
        //  An application would prompt for the password here.
        pdf.userPassword = "secret"
    }

    success = pdf.loadFile(filePath: "qa_data/pdf/encrypted_user_password.pdf")
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    print("loaded, pages: \(pdf.numPages.intValue)")

    //  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

}