Advertise Acceptable Client CA Names for Mutual TLS

See more Socket/SSL/TLS Examples

Demonstrates Socket.AddSslAcceptableClientCaDn, which adds a certificate-authority distinguished name to the list a TLS server advertises when requesting a client certificate for mutual TLS.

The file path is relative to the application's current working directory. An absolute path may also be used. Supply the path appropriate to your own environment.

Dim success As Boolean = False

Dim socket As ChilkatSocket
socket.Initialize("socket")

'  For mutual TLS, advertise the acceptable client-certificate CA distinguished names BEFORE
'  initializing server-side TLS.  Call once for each acceptable CA distinguished name.
success = socket.AddSslAcceptableClientCaDn("CN=Example Root CA, O=Example, C=US")
If success = False Then
    Log(socket.LastErrorText)
    Return
End If

success = socket.AddSslAcceptableClientCaDn("CN=Example Intermediate CA, O=Example, C=US")
If success = False Then
    Log(socket.LastErrorText)
    Return
End If


'  The file path is relative to the application's current working directory.  An absolute path
'  may also be used.  Supply the path appropriate to your own environment.
'  The PFX password should come from a secure source rather than being hard-coded.
Dim pfxPassword As String = "myPfxPassword"
Dim cert As ChilkatCert
cert.Initialize("cert")
success = cert.LoadPfxFile("qa_data/server.pfx", pfxPassword)
If success = False Then
    Log(cert.LastErrorText)
    Return
End If


'  Initialize server-side TLS.  The server will now request a client certificate and advertise the
'  acceptable CA distinguished names added above.
success = socket.InitSslServer(cert)
If success = False Then
    Log(socket.LastErrorText)
    Return
End If

Log("Server-side TLS configured to request client certificates.")