(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.

Note: This example requires Chilkat v10.1.2 or greater.

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

LOCAL loCrypt
LOCAL lcSigningCertSubject
LOCAL lcPfxFilename
LOCAL lcPfxPassword
LOCAL loCertStore
LOCAL lnSuccess
LOCAL loJsonCN
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

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJsonCN = CreateObject('Chilkat.JsonObject')
loJsonCN.UpdateString("CN",lcSigningCertSubject)

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Cert')
loCert = CreateObject('Chilkat.Cert')
lnSuccess = loCertStore.FindCert(loJsonCN,loCert)
IF (lnSuccess = 0) THEN
    ? "Failed to find certificate by subject common name."
    RELEASE loCrypt
    RELEASE loCertStore
    RELEASE loJsonCN
    RELEASE loCert
    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 loCrypt
    RELEASE loCertStore
    RELEASE loJsonCN
    RELEASE loCert
    CANCEL
ENDIF

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

? "Success!"

RELEASE loCrypt
RELEASE loCertStore
RELEASE loJsonCN
RELEASE loCert