PureBasic

PKCS11 Find Certificate with Key Usage on Smart Card or USB Token

See more PKCS11 Examples

Demonstrates how to find and return the 1st certificate on a smart card or USB token with a desired intended key usage.

Note: This example requires Chilkat v9.5.0.91 or later.

PureBasic

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

Procedure ChilkatExample()

    success.i = 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.

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

    CkPkcs11::setCkSharedLibPath(pkcs11, "aetpkss1.dll")

    success = 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.
    ; 
    ; If we don't authenticate, then we won't be able to see the private keys, and thus
    ; we won't know which certificates have an associated private key stored on the smart card.

    ; The smart card PIN is passed to the Login method.
    ; userType 1 indicates a "Normal User".
    userType.i = 1
    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

    ; --------------------------------------------------------------------------

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

    ; Find a certificate with an intended key usage.
    ; Possible key usages to find are:
    ; 
    ; DigitalSignature
    ; NonRepudiation
    ; KeyEncipherment
    ; DataEncipherment
    ; CertificateSigning
    ; CrlSigning
    ; 
    ; To find a cert having any one of several usages, pass a comma-separated list of usages:
    success = CkPkcs11::ckFindCert(pkcs11,"keyUsage","NonRepudiation,DigitalSignature",cert)
    If success = 1
        Debug "Cert with private key: " + CkCert::ckSubjectCN(cert)
    Else
        Debug "No certificates having the intended key usage were found."
    EndIf

    ; --------------------------------------------------------------------------

    ; 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)
        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)
        ProcedureReturn
    EndIf

    Debug "Success."


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


    ProcedureReturn
EndProcedure