(Lianja) 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.

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

loListenSslSocket = createobject("CkSocket")

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

loCert = createobject("CkCert")
llSuccess = loCert.LoadPfxFile("qa_data/serverCert/myServerCert.pfx","pfx_password")
if (llSuccess <> .T.) then
    ? loCert.LastErrorText
    release loListenSslSocket
    release loCert
    return
endif

// 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.
loListenSslSocket.AddSslAcceptableClientCaDn("C=SE, O=AddTrust AB, OU=AddTrust External TTP Network, CN=AddTrust External CA Root")
loListenSslSocket.AddSslAcceptableClientCaDn("O=Digital Signature Trust Co., CN=DST Root CA X3")

// Initialize with our server's TLS certificate.
llSuccess = loListenSslSocket.InitSslServer(loCert)
if (llSuccess <> .T.) then
    ? loListenSslSocket.LastErrorText
    release loListenSslSocket
    release loCert
    return
endif

// Bind and listen on a port:
lnMyPort = 8123
// Allow for a max of 5 queued connect requests.
lnBackLog = 5
llSuccess = loListenSslSocket.BindAndListen(lnMyPort,lnBackLog)
if (llSuccess <> .T.) then
    ? loListenSslSocket.LastErrorText
    release loListenSslSocket
    release loCert
    return
endif

// Accept the next incoming connection.
lnMaxWaitMillisec = 20000
loClientSock = loListenSslSocket.AcceptNextConnection(lnMaxWaitMillisec)
if (loListenSslSocket.LastMethodSuccess = .F.) then
    ? loListenSslSocket.LastErrorText
    release loListenSslSocket
    release loCert
    return
endif

// 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.
lnNumClientCerts = loClientSock.NumReceivedClientCerts
? "numClientCerts = " + str(lnNumClientCerts)

i = 0
do while i < lnNumClientCerts
    loClientCert = loClientSock.GetReceivedClientCert(i)
    ? loClientCert.SubjectDN
    release loClientCert
    i = i + 1
enddo

// Close the connection with the client
llSuccess = loClientSock.Close(1000)

release loClientSock


release loListenSslSocket
release loCert