(DataFlex) Accept TLS Connection with Client Authentication

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".

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-9.5.0-win32.pkg

Procedure Test
    Handle hoListenSslSocket
    Variant vCert
    Handle hoCert
    Boolean iSuccess
    Integer iMyPort
    Integer iBackLog
    Variant vClientSock
    Handle hoClientSock
    Integer iMaxWaitMillisec
    String sReceivedMsg
    String sTemp1
    Boolean bTemp1

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

    Get Create (RefClass(cComChilkatSocket)) To hoListenSslSocket
    If (Not(IsComObjectCreated(hoListenSslSocket))) Begin
        Send CreateComObject of hoListenSslSocket
    End

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

    Get Create (RefClass(cComChilkatCert)) To hoCert
    If (Not(IsComObjectCreated(hoCert))) Begin
        Send CreateComObject of hoCert
    End
    // The 1st argument is the file path, the 2nd arg is the 
    // PFX file's password:
    Get ComLoadPfxFile Of hoCert "chilkat.pfx" "test" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoCert To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // 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.
    Get ComAddSslAcceptableClientCaDn Of hoListenSslSocket "C=SE, O=AddTrust AB, OU=AddTrust External TTP Network, CN=AddTrust External CA Root" To iSuccess
    Get ComAddSslAcceptableClientCaDn Of hoListenSslSocket "O=Digital Signature Trust Co., CN=DST Root CA X3" To iSuccess

    // Use the certificate:
    Get pvComObject of hoCert to vCert
    Get ComInitSslServer Of hoListenSslSocket vCert To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoListenSslSocket To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Bind and listen on a port:
    Move 8123 To iMyPort
    // Allow for a max of 5 queued connect requests.
    Move 5 To iBackLog
    Get ComBindAndListen Of hoListenSslSocket iMyPort iBackLog To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoListenSslSocket To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // 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 
    // AcceptNextConnection can hang indefinitely during the SSL handshake process. 
    // Make sure these properties are set to appropriate values before calling AcceptNextConnection.

    // Set a 10 second max for waiting to read/write.  This is for the SSL/TLS handshake establishment.
    Set ComMaxReadIdleMs Of hoListenSslSocket To 10000
    Set ComMaxSendIdleMs Of hoListenSslSocket To 10000

    // Accept a single client connection and establish the secure SSL/TLS channel:

    Move 20000 To iMaxWaitMillisec
    Get ComAcceptNextConnection Of hoListenSslSocket iMaxWaitMillisec To vClientSock
    If (IsComObject(vClientSock)) Begin
        Get Create (RefClass(cComChilkatSocket)) To hoClientSock
        Set pvComObject Of hoClientSock To vClientSock
    End
    Get ComLastMethodSuccess Of hoListenSslSocket To bTemp1
    If (bTemp1 = False) Begin
        Get ComLastErrorText Of hoListenSslSocket To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // The client (in this example) is going to send a "Hello Server! -EOM-" 
    // message.  Read it:
    Get ComReceiveUntilMatch Of hoClientSock "-EOM-" To sReceivedMsg
    Get ComLastMethodSuccess Of hoClientSock To bTemp1
    If (bTemp1 <> True) Begin
        Get ComLastErrorText Of hoClientSock To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln sReceivedMsg

    // Send a "Hello Client! -EOM-" message:
    Get ComSendString Of hoClientSock "Hello Client! -EOM-" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoClientSock To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Close the connection with the client
    // Wait a max of 20 seconds (20000 millsec)
    Get ComClose Of hoClientSock 20000 To iSuccess

    Send Destroy of hoClientSock


End_Procedure