(PureBasic) Get the Server Certificate, Certificate Chain, and Root CA Certificate

Demonstrates how to get the HTTP server certificate, its certificate chain, and the root CA certificate.

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkCert.pb"
IncludeFile "CkHttp.pb"
IncludeFile "CkCertChain.pb"

Procedure ChilkatExample()

    success.i = 0

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

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

    ; We're getting the SSL/TLS certificate, so make sure to connect to the SSL/TLS port (443).
    sslCert.i = CkCert::ckCreate()
    If sslCert.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkHttp::ckGetServerCert(http,"apple.com",443,sslCert)
    If success = 0
        Debug CkHttp::ckLastErrorText(http)
        CkHttp::ckDispose(http)
        CkCert::ckDispose(sslCert)
        ProcedureReturn
    EndIf

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

    success = CkCert::ckBuildCertChain(sslCert,certChain)
    If success = 0
        Debug CkCert::ckLastErrorText(sslCert)
        CkHttp::ckDispose(http)
        CkCert::ckDispose(sslCert)
        CkCertChain::ckDispose(certChain)
        ProcedureReturn
    EndIf

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

    i.i = 0
    numCerts.i = CkCertChain::ckNumCerts(certChain)
    While i < numCerts
        CkCertChain::ckCertAt(certChain,i,cert)
        Debug "SubjectDN " + Str(i) + ": " + CkCert::ckSubjectDN(cert)
        Debug "IssuerDN " + Str(i) + ": " + CkCert::ckIssuerDN(cert)
        i = i + 1
    Wend

    ; If the certificate chain reaches the root CA cert, then the last cert in the chain
    ; is the root CA cert.
    If CkCertChain::ckReachesRoot(certChain) = 1
        caCert.i = CkCert::ckCreate()
        If caCert.i = 0
            Debug "Failed to create object."
            ProcedureReturn
        EndIf

        CkCertChain::ckCertAt(certChain,numCerts - 1,caCert)
        Debug "CA Root Cert: " + CkCert::ckSubjectDN(caCert)
    EndIf



    CkHttp::ckDispose(http)
    CkCert::ckDispose(sslCert)
    CkCertChain::ckDispose(certChain)
    CkCert::ckDispose(cert)
    CkCert::ckDispose(caCert)


    ProcedureReturn
EndProcedure