Visual FoxPro Requires Chilkat v11.0.0+

Accept TLS Connection with Client Authentication

See more Socket/SSL/TLS Examples

Demonstrates how to accept a TLS connection requiring client authentication. This is the case where the TLS client sends a certificate. It is also known as "Two-Way SSL". Visual FoxPro

LOCAL lnSuccess
LOCAL loListenSslSocket
LOCAL loCert
LOCAL lnMyPort
LOCAL lnBackLog
LOCAL lnMaxWaitMillisec
LOCAL loClientSock
LOCAL lcReceivedMsg

lnSuccess = 0

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

loListenSslSocket = CreateObject('Chilkat.Socket')

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

loCert = CreateObject('Chilkat.Cert')
*  The 1st argument is the file path, the 2nd arg is the 
*  PFX file's password:
lnSuccess = loCert.LoadPfxFile("chilkat.pfx","test")
IF (lnSuccess = 0) THEN
    ? loCert.LastErrorText
    RELEASE loListenSslSocket
    RELEASE loCert
    CANCEL
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")

*  Use the certificate:
lnSuccess = loListenSslSocket.InitSslServer(loCert)
IF (lnSuccess = 0) THEN
    ? loListenSslSocket.LastErrorText
    RELEASE loListenSslSocket
    RELEASE loCert
    CANCEL
ENDIF

*  Bind and listen on a port:
lnMyPort = 8123
*  Allow for a max of 5 queued connect requests.
lnBackLog = 5
lnSuccess = loListenSslSocket.BindAndListen(lnMyPort,lnBackLog)
IF (lnSuccess = 0) THEN
    ? loListenSslSocket.LastErrorText
    RELEASE loListenSslSocket
    RELEASE loCert
    CANCEL
ENDIF

*  If accepting an SSL/TLS connection, the SSL handshake is part of the connection
*  establishment process. This involves a few back-and-forth messages between the 
*  client and server to establish algorithms and a shared key to create the secure 
*  channel. The sending and receiving of these messages are governed by the 
*  MaxReadIdleMs and MaxSendIdleMs properties. If these properties are set to 0 
*  (and this is the default unless changed by your application), then the 
*  AcceptNext can hang indefinitely during the SSL handshake process. 
*  Make sure these properties are set to appropriate values before calling AcceptNext.

*  Set a 10 second max for waiting to read/write.  This is for the SSL/TLS handshake establishment.
loListenSslSocket.MaxReadIdleMs = 10000
loListenSslSocket.MaxSendIdleMs = 10000

*  Accept a single client connection and establish the secure SSL/TLS channel:
lnMaxWaitMillisec = 20000
loClientSock = CreateObject('Chilkat.Socket')
lnSuccess = loListenSslSocket.AcceptNext(lnMaxWaitMillisec,loClientSock)
IF (lnSuccess = 0) THEN
    ? loListenSslSocket.LastErrorText
    RELEASE loListenSslSocket
    RELEASE loCert
    RELEASE loClientSock
    CANCEL
ENDIF

*  The client (in this example) is going to send a "Hello Server! -EOM-" 
*  message.  Read it:
lcReceivedMsg = loClientSock.ReceiveUntilMatch("-EOM-")
IF (loClientSock.LastMethodSuccess = 0) THEN
    ? loClientSock.LastErrorText
    RELEASE loListenSslSocket
    RELEASE loCert
    RELEASE loClientSock
    CANCEL
ENDIF

? lcReceivedMsg

*  Send a "Hello Client! -EOM-" message:
lnSuccess = loClientSock.SendString("Hello Client! -EOM-")
IF (lnSuccess = 0) THEN
    ? loClientSock.LastErrorText
    RELEASE loListenSslSocket
    RELEASE loCert
    RELEASE loClientSock
    CANCEL
ENDIF

*  Close the connection with the client
*  Wait a max of 20 seconds (20000 millsec)
lnSuccess = loClientSock.Close(20000)

RELEASE loListenSslSocket
RELEASE loCert
RELEASE loClientSock