(Lianja) 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.

Chilkat Lianja Extension Download Chilkat Lianja Extension

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

loPdf = createobject("CkPdf")

// Load a PDF to be signed.
// The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
llSuccess = loPdf.LoadFile("qa_data/pdf/hello.pdf")
if (llSuccess = .F.) then
    ? loPdf.LastErrorText
    release loPdf
    return
endif

// Options for signing are specified in JSON.
loJson = createobject("CkJsonObject")

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

// Indicate that the signature will be invisible.
loJson.UpdateBool("invisibleSignature",.T.)

// Load the signing certificate. (Use your own certificate.)
loCert = createobject("CkCert")
llSuccess = loCert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","secret")
if (llSuccess = .F.) then
    ? loCert.LastErrorText
    release loPdf
    release loJson
    release loCert
    return
endif

// Tell the pdf object to use the certificate for signing.
llSuccess = loPdf.SetSigningCert(loCert)
if (llSuccess = .F.) then
    ? loPdf.LastErrorText
    release loPdf
    release loJson
    release loCert
    return
endif

llSuccess = loPdf.SignPdf(loJson,"qa_output/hello_signed.pdf")
if (llSuccess = .F.) then
    ? loPdf.LastErrorText
    release loPdf
    release loJson
    release loCert
    return
endif

? "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:



release loPdf
release loJson
release loCert