Visual FoxPro

PKCS11 Certificate Chain

See more PKCS11 Examples

Demonstrates how to make CA certs available for the certificate chain to be included when creating a signature (using a PKCS11 compatible smart card / USB token) such as for PDF, XMLDSig, etc.

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

Visual FoxPro

LOCAL lnSuccess
LOCAL loPkcs11
LOCAL lnSlotID
LOCAL lnReadWrite
LOCAL lnUserType
LOCAL lcPin
LOCAL loCert
LOCAL loCertVault

lnSuccess = 0

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

* Note: Chilkat's PKCS11 implementation runs on Windows, Linux, Mac OS X, and other supported operating systems.

loPkcs11 = CreateObject('Chilkat.Pkcs11')

* You will use the DLL (or shared lib) provided by your smart card vendor, or a DLL compatible with your smart card.
* On Windows, if the DLL is located in C:\Windows\System32, specify only the filename.
* Otherwise provide the full path.
loPkcs11.SharedLibPath = "bit4xpki.dll"

lnSuccess = loPkcs11.Initialize()
IF (lnSuccess = 0) THEN
    ? loPkcs11.LastErrorText
    RELEASE loPkcs11
    CANCEL
ENDIF

* Pass -1 for the slotID to open a session on the first non-empty slot.
lnSlotID = -1

* Open a session.
lnReadWrite = 1
lnSuccess = loPkcs11.OpenSession(lnSlotID,lnReadWrite)
IF (lnSuccess = 0) THEN
    ? loPkcs11.LastErrorText
    RELEASE loPkcs11
    CANCEL
ENDIF

* Make it an authenticated session by calling Login.
lnUserType = 1
* Make sure to use the correct PIN for your smart card..
lcPin = "0000"
lnSuccess = loPkcs11.Login(lnUserType,lcPin)
IF (lnSuccess = 0) THEN
    ? loPkcs11.LastErrorText
    lnSuccess = loPkcs11.CloseSession()
    RELEASE loPkcs11
    CANCEL
ENDIF

* Get the certificate (on the smart card) that has a private key.
loCert = CreateObject('Chilkat.Cert')
lnSuccess = loPkcs11.FindCert("privateKey","",loCert)
IF (lnSuccess = 1) THEN
    ? "Cert with private key: " + loCert.SubjectCN
ELSE
    ? "No certificates having a private key were found."
    lnSuccess = loPkcs11.CloseSession()
    RELEASE loPkcs11
    RELEASE loCert
    CANCEL
ENDIF

* If the certificates in the chain of authentication were contained on the smart card,
* then Chilkat would already have them (via the FindCert function) and the certs in the chain will be automatically used
* as needed when signing occurs.

* If you have CA certs located elsewhere, such as in .cer files, you can make them available to Chilkat in the following way:

loCertVault = CreateObject('Chilkat.XmlCertVault')
* Please review the methods available in the XML certificate vault class.  Different methods exist for adding certificates
* from various sources, such as PEM, PFX, or in-memory sources..
lnSuccess = loCertVault.AddCertFile("someDir/caIntermediateCert.cer")
* ...
lnSuccess = loCertVault.AddCertFile("someDir/caCert.cer")
* (Your code should check the return value to make sure it succeeded.)

lnSuccess = loCert.UseCertVault(loCertVault)
IF (lnSuccess = 0) THEN
    ? loCert.LastErrorText
    lnSuccess = loPkcs11.CloseSession()
    RELEASE loPkcs11
    RELEASE loCert
    RELEASE loCertVault
    CANCEL
ENDIF

* --------------------------------------------------------------------------
* At this point, we have the cert (and certs in the chain of authentication) to be used for signing.
* The code for using the certificate in creating the digital signature, such as for a PDF, XML, etc., go here...

* --------------------------------------------------------------------------

* Revert to an unauthenticated session by calling Logout.
lnSuccess = loPkcs11.Logout()
IF (lnSuccess = 0) THEN
    ? loPkcs11.LastErrorText
    lnSuccess = loPkcs11.CloseSession()
    RELEASE loPkcs11
    RELEASE loCert
    RELEASE loCertVault
    CANCEL
ENDIF

* When finished, close the session.
* It is important to close the session (memory leaks will occur if the session is not properly closed).
lnSuccess = loPkcs11.CloseSession()
IF (lnSuccess = 0) THEN
    ? loPkcs11.LastErrorText
    RELEASE loPkcs11
    RELEASE loCert
    RELEASE loCertVault
    CANCEL
ENDIF

? "Success."

RELEASE loPkcs11
RELEASE loCert
RELEASE loCertVault