Swift

Sign PDF with Invisible Signature

See more PDF Signatures Examples

Demonstrates how to sign a PDF with an invisible signature.

Note: This example requires Chilkat v9.5.0.85 or greater.

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.

    let pdf = CkoPdf()!

    // Load a PDF to be signed.
    // The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
    success = pdf.loadFile(filePath: "qa_data/pdf/hello.pdf")
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    // Options for signing are specified in JSON.
    let json = CkoJsonObject()!

    // In most cases, the signingCertificateV2 and signingTime attributes are required.
    json.updateInt(jsonPath: "signingCertificateV2", value: 1)
    json.updateInt(jsonPath: "signingTime", value: 1)

    // Indicate that the signature will be invisible.
    json.updateBool(jsonPath: "invisibleSignature", value: true)

    // Load the signing certificate. (Use your own certificate.)
    let cert = CkoCert()!
    success = cert.loadPfxFile(path: "qa_data/pfx/myPdfSigningCert.pfx", password: "secret")
    if success == false {
        print("\(cert.lastErrorText!)")
        return
    }

    // Tell the pdf object to use the certificate for signing.
    success = pdf.setSigningCert(cert: cert)
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    success = pdf.sign(jsonOptions: json, outFilePath: "qa_output/hello_signed.pdf")
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    print("PDF successfully signed with an invisible signature.")

    // An invisible signature has no appearance within the PDF document itself,
    // but Adobe Acrobat will indicate the document is signed in a toolbar, as shown here:
    // (image:https://example-code.com/images/invisible_signature.jpg/endImage)

}