(Visual FoxPro) Sign a File to Create a .p7s (Detached Signature)

Visual FoxPro example to create a detached signature file (.p7s) for any type file. The signature can be verified by calling VerifyP7S and passing the original filename and the .p7s filename.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loCrypt
LOCAL lcSigningCertSubject
LOCAL lcPfxFilename
LOCAL lcPfxPassword
LOCAL loCertStore
LOCAL lnSuccess
LOCAL loCert
LOCAL lcInFile
LOCAL lcSigFile

* 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.Crypt2')
loCrypt = CreateObject('Chilkat.Crypt2')

* Use a digital certificate and private key from a PFX file (.pfx or .p12).
lcSigningCertSubject = "Acme Inc"
lcPfxFilename = "/Users/chilkat/testData/pfx/acme.pfx"
lcPfxPassword = "test123"

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.CertStore')
loCertStore = CreateObject('Chilkat.CertStore')
lnSuccess = loCertStore.LoadPfxFile(lcPfxFilename,lcPfxPassword)
IF (lnSuccess <> 1) THEN
    ? loCertStore.LastErrorText
    RELEASE loCrypt
    RELEASE loCertStore
    CANCEL
ENDIF

loCert = loCertStore.FindCertBySubjectCN(lcSigningCertSubject)
IF (loCertStore.LastMethodSuccess = 0) THEN
    ? "Failed to find certificate by subject common name."
    RELEASE loCrypt
    RELEASE loCertStore
    CANCEL
ENDIF

* Tell the crypt component to use this cert.
lnSuccess = loCrypt.SetSigningCert(loCert)

* We can sign any type of file, creating a .p7s as output:
lcInFile = "/Users/chilkat/testData/pdf/sample.pdf"
lcSigFile = "/Users/chilkat/testData/p7s/sample.p7s"

lnSuccess = loCrypt.CreateP7S(lcInFile,lcSigFile)
IF (lnSuccess = 0) THEN
    ? loCrypt.LastErrorText
    RELEASE loCert
    RELEASE loCrypt
    RELEASE loCertStore
    CANCEL
ENDIF

lnSuccess = loCrypt.VerifyP7S(lcInFile,lcSigFile)
IF (lnSuccess = 0) THEN
    ? loCrypt.LastErrorText
    RELEASE loCert
    RELEASE loCrypt
    RELEASE loCertStore
    CANCEL
ENDIF

RELEASE loCert

? "Success!"

RELEASE loCrypt
RELEASE loCertStore