Go

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.

Go

    success := false

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    pdf := chilkat.NewPdf()

    // Load a PDF to be signed.
    // The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
    success = pdf.LoadFile("qa_data/pdf/hello.pdf")
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        return
    }

    // Options for signing are specified in JSON.
    json := chilkat.NewJsonObject()

    // In most cases, the signingCertificateV2 and signingTime attributes are required.
    json.UpdateInt("signingCertificateV2",1)
    json.UpdateInt("signingTime",1)

    // Indicate that the signature will be invisible.
    json.UpdateBool("invisibleSignature",true)

    // Load the signing certificate. (Use your own certificate.)
    cert := chilkat.NewCert()
    success = cert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","secret")
    if success == false {
        fmt.Println(cert.LastErrorText())
        pdf.DisposePdf()
        json.DisposeJsonObject()
        cert.DisposeCert()
        return
    }

    // Tell the pdf object to use the certificate for signing.
    success = pdf.SetSigningCert(cert)
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        json.DisposeJsonObject()
        cert.DisposeCert()
        return
    }

    success = pdf.SignPdf(json,"qa_output/hello_signed.pdf")
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        json.DisposeJsonObject()
        cert.DisposeCert()
        return
    }

    fmt.Println("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)

    pdf.DisposePdf()
    json.DisposeJsonObject()
    cert.DisposeCert()