Delphi DLL 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". Delphi DLL

var
success: Boolean;
listenSslSocket: HCkSocket;
cert: HCkCert;
myPort: Integer;
backLog: Integer;
maxWaitMillisec: Integer;
clientSock: HCkSocket;
receivedMsg: PWideChar;

begin
success := False;

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

listenSslSocket := CkSocket_Create();

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

cert := CkCert_Create();
//  The 1st argument is the file path, the 2nd arg is the 
//  PFX file's password:
success := CkCert_LoadPfxFile(cert,'chilkat.pfx','test');
if (success = False) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert));
    Exit;
  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.
CkSocket_AddSslAcceptableClientCaDn(listenSslSocket,'C=SE, O=AddTrust AB, OU=AddTrust External TTP Network, CN=AddTrust External CA Root');
CkSocket_AddSslAcceptableClientCaDn(listenSslSocket,'O=Digital Signature Trust Co., CN=DST Root CA X3');

//  Use the certificate:
success := CkSocket_InitSslServer(listenSslSocket,cert);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSocket__lastErrorText(listenSslSocket));
    Exit;
  end;

//  Bind and listen on a port:
myPort := 8123;
//  Allow for a max of 5 queued connect requests.
backLog := 5;
success := CkSocket_BindAndListen(listenSslSocket,myPort,backLog);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSocket__lastErrorText(listenSslSocket));
    Exit;
  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 
//  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.
CkSocket_putMaxReadIdleMs(listenSslSocket,10000);
CkSocket_putMaxSendIdleMs(listenSslSocket,10000);

//  Accept a single client connection and establish the secure SSL/TLS channel:
maxWaitMillisec := 20000;
clientSock := CkSocket_Create();
success := CkSocket_AcceptNext(listenSslSocket,maxWaitMillisec,clientSock);
if (success = False) then
  begin
    Memo1.Lines.Add(CkSocket__lastErrorText(listenSslSocket));
    Exit;
  end;

//  The client (in this example) is going to send a "Hello Server! -EOM-" 
//  message.  Read it:
receivedMsg := CkSocket__receiveUntilMatch(clientSock,'-EOM-');
if (CkSocket_getLastMethodSuccess(clientSock) = False) then
  begin
    Memo1.Lines.Add(CkSocket__lastErrorText(clientSock));
    Exit;
  end;

Memo1.Lines.Add(receivedMsg);

//  Send a "Hello Client! -EOM-" message:
success := CkSocket_SendString(clientSock,'Hello Client! -EOM-');
if (success = False) then
  begin
    Memo1.Lines.Add(CkSocket__lastErrorText(clientSock));
    Exit;
  end;

//  Close the connection with the client
//  Wait a max of 20 seconds (20000 millsec)
success := CkSocket_Close(clientSock,20000);

CkSocket_Dispose(listenSslSocket);
CkCert_Dispose(cert);
CkSocket_Dispose(clientSock);