(Go) Examine Client Certificates for an Accepted TLS Connection

Demonstrates how to access the client certificates for a TLS connection accepted by your application acting as the server.

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

Chilkat Go Downloads Go Package for Windows, MacOS, Linux, Alpine Linux, Solaris

    success := false

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

    listenSslSocket := Socket_Ref.html">chilkat.NewSocket()

    // An SSL/TLS server needs a digital certificate.  This example loads it from a PFX file.
    // This is the server's certificate.

    cert := Cert_Ref.html">chilkat.NewCert()
    success = cert.LoadPfxFile("qa_data/serverCert/myServerCert.pfx","pfx_password")
    if success == false {
        fmt.Println(cert.LastErrorText())
        listenSslSocket.DisposeSocket()
        cert.DisposeCert()
        return
    }

    // To accept client client certificates in the TLS handshake,
    // we must indicate a list of acceptable client certificate root CA DN's
    // that are allowed.  (DN is an acronym for Distinguished Name.)
    // Call AddSslAcceptableClientCaDn once for each acceptable CA DN.
    // Here are a few examples so you can see the general format of a DN.
    listenSslSocket.AddSslAcceptableClientCaDn("C=SE, O=AddTrust AB, OU=AddTrust External TTP Network, CN=AddTrust External CA Root")
    listenSslSocket.AddSslAcceptableClientCaDn("O=Digital Signature Trust Co., CN=DST Root CA X3")

    // Initialize with our server's TLS certificate.
    success = listenSslSocket.InitSslServer(cert)
    if success == false {
        fmt.Println(listenSslSocket.LastErrorText())
        listenSslSocket.DisposeSocket()
        cert.DisposeCert()
        return
    }

    // Bind and listen on a port:
    myPort := 8123
    // Allow for a max of 5 queued connect requests.
    backLog := 5
    success = listenSslSocket.BindAndListen(myPort,backLog)
    if success == false {
        fmt.Println(listenSslSocket.LastErrorText())
        listenSslSocket.DisposeSocket()
        cert.DisposeCert()
        return
    }

    // Accept the next incoming connection.
    maxWaitMillisec := 20000

    clientSock := Socket_Ref.html">chilkat.NewSocket()
    success = listenSslSocket.AcceptNext(maxWaitMillisec,clientSock)
    if success == false {
        fmt.Println(listenSslSocket.LastErrorText())
        listenSslSocket.DisposeSocket()
        cert.DisposeCert()
        clientSock.DisposeSocket()
        return
    }

    // Examine the client certs chain.  The 1st cert will be the client certificate, and
    // the subsequent certs will be the certs in the chain of authentication.
    numClientCerts := clientSock.NumReceivedClientCerts()
    fmt.Println("numClientCerts = ", numClientCerts)

    clientCert := Cert_Ref.html">chilkat.NewCert()
    i := 0
    for i < numClientCerts {
        clientSock.GetRcvdClientCert(i,clientCert)
        fmt.Println(clientCert.SubjectDN())
        i = i + 1
    }

    // Close the connection with the client
    success = clientSock.Close(1000)

    listenSslSocket.DisposeSocket()
    cert.DisposeCert()
    clientSock.DisposeSocket()
    clientCert.DisposeCert()