Visual FoxPro

Sign a PDF using SmartCard or HSM (Hardware Security Module)

See more PDF Signatures Examples

This example demonstrates how to a sign a PDF using a smartcard or HSM (hardware security module).

Note: This example requires Chilkat v9.5.0.88 or greater.

Visual FoxPro

LOCAL lnSuccess
LOCAL loPdf
LOCAL loJson
LOCAL loCert

lnSuccess = 0

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

loPdf = CreateObject('Chilkat.Pdf')

* Load a PDF to be signed.
* 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.
loJson = CreateObject('Chilkat.JsonObject')

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

* Use a certificate on a smartcard or USB token.
loCert = CreateObject('Chilkat.Cert')

* Provide the smartcard PIN.
* Set the smartcard PIN prior to calling LoadFromSmartcard.
* If the PIN is not explicitly provided here, the Windows OS should
* display a dialog for the PIN.
loCert.SmartCardPin = "123456"

* Load the certificate on the smartcard currently in the reader (or on the USB token).
* Pass an empty string to allow Chilkat to automatically choose the CSP (Cryptographi Service Provider).
* See Load Certificate on Smartcard for information about explicitly selecting a particular CSP.
lnSuccess = loCert.LoadFromSmartcard("")
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_hsm.pdf")
IF (lnSuccess = 0) THEN
    ? loPdf.LastErrorText
    RELEASE loPdf
    RELEASE loJson
    RELEASE loCert
    CANCEL
ENDIF

? "The PDF has been successfully cryptographically signed using an HSM."

RELEASE loPdf
RELEASE loJson
RELEASE loCert