(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.

Chilkat PureBasic Module Download Chilkat PureBasic Module

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

Procedure ChilkatExample()

    ; 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 = CkHttp::ckGetServerSslCert(http,"nationalgeographic.com",443)
    If CkHttp::ckLastMethodSuccess(http) = 0
        Debug CkHttp::ckLastErrorText(http)
        CkHttp::ckDispose(http)
        ProcedureReturn
    EndIf

    ; Note: Prior to v9.5.0.50, this method would fail if the certificate chain could not 
    ; be completed to the root.  Starting in v9.5.0.50, the incomplete certificate chain 
    ; will be returned.  The certificate chain's ReachesRoot property can be examined to 
    ; see if the chain was completed to the root.
    certChain.i = CkCert::ckGetCertChain(sslCert)
    If CkCert::ckLastMethodSuccess(sslCert) = 0
        Debug CkCert::ckLastErrorText(sslCert)
        CkCert::ckDispose(sslCert)

        CkHttp::ckDispose(http)
        ProcedureReturn
    EndIf

    i.i = 0
    numCerts.i = CkCertChain::ckNumCerts(certChain)
    While i < numCerts
        cert.i = CkCertChain::ckGetCert(certChain,i)
        Debug "SubjectDN " + Str(i) + ": " + CkCert::ckSubjectDN(cert)
        Debug "IssuerDN " + Str(i) + ": " + CkCert::ckIssuerDN(cert)
        CkCert::ckDispose(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 = CkCertChain::ckGetCert(certChain,numCerts - 1)
        Debug "CA Root Cert: " + CkCert::ckSubjectDN(caCert)
        CkCert::ckDispose(caCert)

    EndIf

    CkCert::ckDispose(sslCert)

    CkCertChain::ckDispose(certChain)



    CkHttp::ckDispose(http)


    ProcedureReturn
EndProcedure