B4X Requires Chilkat v11.0.0+

Examine Client Certificates for an Accepted TLS Connection

See more Socket/SSL/TLS Examples

Demonstrates how to access the client certificates for a TLS connection accepted by your application acting as the server. B4X

Dim success As Boolean = False

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

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

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

Dim cert As ChilkatCert
cert.Initialize("cert")
success = cert.LoadPfxFile("qa_data/serverCert/myServerCert.pfx", "pfx_password")
If success = False Then
    Log(cert.LastErrorText)
    Return
End If


'  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 Then
    Log(listenSslSocket.LastErrorText)
    Return
End If


'  Bind and listen on a port:
Dim myPort As Int = 8123
'  Allow for a max of 5 queued connect requests.
Dim backLog As Int = 5
success = listenSslSocket.BindAndListen(myPort, backLog)
If success = False Then
    Log(listenSslSocket.LastErrorText)
    Return
End If


'  Accept the next incoming connection.
Dim maxWaitMillisec As Int = 20000

Dim clientSock As ChilkatSocket
clientSock.Initialize("clientSock")
success = listenSslSocket.AcceptNext(maxWaitMillisec, clientSock)
If success = False Then
    Log(listenSslSocket.LastErrorText)
    Return
End If


'  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.
Dim numClientCerts As Int = clientSock.NumReceivedClientCerts
Log("numClientCerts = " & numClientCerts)

Dim clientCert As ChilkatCert
clientCert.Initialize("clientCert")
Dim i As Int = 0
Do While i < numClientCerts
    clientSock.GetRcvdClientCert(i, clientCert)
    Log(clientCert.SubjectDN)
    i = i + 1
Loop

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