(PureBasic) 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.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkPkcs11.pb"
IncludeFile "CkCert.pb"
IncludeFile "CkXmlCertVault.pb"

Procedure ChilkatExample()

    ; 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.

    pkcs11.i = CkPkcs11::ckCreate()
    If pkcs11.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; 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.
    CkPkcs11::setCkSharedLibPath(pkcs11, "bit4xpki.dll")

    success.i = CkPkcs11::ckInitialize(pkcs11)
    If success = 0
        Debug CkPkcs11::ckLastErrorText(pkcs11)
        CkPkcs11::ckDispose(pkcs11)
        ProcedureReturn
    EndIf

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

    ; Open a session.
    readWrite.i = 1
    success = CkPkcs11::ckOpenSession(pkcs11,slotID,readWrite)
    If success = 0
        Debug CkPkcs11::ckLastErrorText(pkcs11)
        CkPkcs11::ckDispose(pkcs11)
        ProcedureReturn
    EndIf

    ; Make it an authenticated session by calling Login.
    userType.i = 1
    ; Make sure to use the correct PIN for your smart card..
    pin.s = "0000"
    success = CkPkcs11::ckLogin(pkcs11,userType,pin)
    If success = 0
        Debug CkPkcs11::ckLastErrorText(pkcs11)
        success = CkPkcs11::ckCloseSession(pkcs11)
        CkPkcs11::ckDispose(pkcs11)
        ProcedureReturn
    EndIf

    ; Get the certificate (on the smart card) that has a private key.
    cert.i = CkCert::ckCreate()
    If cert.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkPkcs11::ckFindCert(pkcs11,"privateKey","",cert)
    If success = 1
        Debug "Cert with private key: " + CkCert::ckSubjectCN(cert)
    Else
        Debug "No certificates having a private key were found."
        success = CkPkcs11::ckCloseSession(pkcs11)
        CkPkcs11::ckDispose(pkcs11)
        CkCert::ckDispose(cert)
        ProcedureReturn
    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:

    certVault.i = CkXmlCertVault::ckCreate()
    If certVault.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; 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..
    success = CkXmlCertVault::ckAddCertFile(certVault,"someDir/caIntermediateCert.cer")
    ; ...
    success = CkXmlCertVault::ckAddCertFile(certVault,"someDir/caCert.cer")
    ; (Your code should check the return value to make sure it succeeded.)

    success = CkCert::ckUseCertVault(cert,certVault)
    If success = 0
        Debug CkCert::ckLastErrorText(cert)
        success = CkPkcs11::ckCloseSession(pkcs11)
        CkPkcs11::ckDispose(pkcs11)
        CkCert::ckDispose(cert)
        CkXmlCertVault::ckDispose(certVault)
        ProcedureReturn
    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.
    success = CkPkcs11::ckLogout(pkcs11)
    If success = 0
        Debug CkPkcs11::ckLastErrorText(pkcs11)
        success = CkPkcs11::ckCloseSession(pkcs11)
        CkPkcs11::ckDispose(pkcs11)
        CkCert::ckDispose(cert)
        CkXmlCertVault::ckDispose(certVault)
        ProcedureReturn
    EndIf

    ; When finished, close the session.
    ; It is important to close the session (memory leaks will occur if the session is not properly closed).
    success = CkPkcs11::ckCloseSession(pkcs11)
    If success = 0
        Debug CkPkcs11::ckLastErrorText(pkcs11)
        CkPkcs11::ckDispose(pkcs11)
        CkCert::ckDispose(cert)
        CkXmlCertVault::ckDispose(certVault)
        ProcedureReturn
    EndIf

    Debug "Success."


    CkPkcs11::ckDispose(pkcs11)
    CkCert::ckDispose(cert)
    CkXmlCertVault::ckDispose(certVault)


    ProcedureReturn
EndProcedure