(Visual FoxPro) Certify a PDF and Lock the Entire Document

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This example demonstrates how to a sign a certify a PDF and lock the entire document. Normally this is intended to seal the document with a final approving (or dissapproving) signature; usually after a review workflow is completed and normally reserved for the creator or author of a document.

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LOCAL loPdf
LOCAL lnSuccess
LOCAL loJson
LOCAL loCert

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

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Pdf')
loPdf = CreateObject('Chilkat.Pdf')

* Load a PDF to be certified and locked.
* The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
lnSuccess = loPdf.LoadFile("qa_data/pdf/hello.pdf")
IF (lnSuccess = 0) THEN
    ? loPdf.LastErrorText
    RELEASE loPdf
    CANCEL
ENDIF

* Options for signing are specified in JSON.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJson = CreateObject('Chilkat.JsonObject')

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

* The only coding difference with certifying and locking a PDF
* as compared with an approval signature (also known as recipient signature)
* is to add the "lockAfterSigning" and "docMDP.add" to the json.
loJson.UpdateBool("lockAfterSigning",1)
loJson.UpdateBool("docMDP.add",1)

* Put the signature on page 1, top left
loJson.UpdateInt("page",1)
loJson.UpdateString("appearance.y","top")
loJson.UpdateString("appearance.x","left")

* Use a font scale of 10.0
loJson.UpdateString("appearance.fontScale","10.0")

* In this example, the appearance of the digital signature will contain three lines:
* 1) The signing certificate's common name
* 2) The current date/time
* 3) Some arbitrary text.
* The keyword "cert_cn" is replaced with the Certificate's Subject Common Name.
* The keyword "current_dt" is replaced with the current date/time.
* Any number of appearance text lines can be added.
loJson.UpdateString("appearance.text[0]","Digitally signed by: cert_cn")
loJson.UpdateString("appearance.text[1]","current_dt")
loJson.UpdateString("appearance.text[2]","The crazy brown fox jumps over the lazy dog.")

* Load the signing certificate. (Use your own certificate.)
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Cert')
loCert = CreateObject('Chilkat.Cert')
lnSuccess = loCert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","secret")
IF (lnSuccess = 0) THEN
    ? loCert.LastErrorText
    RELEASE loPdf
    RELEASE loJson
    RELEASE loCert
    CANCEL
ENDIF

* Tell the pdf object to use the certificate for signing.
lnSuccess = loPdf.SetSigningCert(loCert)
IF (lnSuccess = 0) THEN
    ? loPdf.LastErrorText
    RELEASE loPdf
    RELEASE loJson
    RELEASE loCert
    CANCEL
ENDIF

lnSuccess = loPdf.SignPdf(loJson,"qa_output/hello_signed.pdf")
IF (lnSuccess = 0) THEN
    ? loPdf.LastErrorText
    RELEASE loPdf
    RELEASE loJson
    RELEASE loCert
    CANCEL
ENDIF

? "The PDF has been successfully certified and locked."

RELEASE loPdf
RELEASE loJson
RELEASE loCert