TScAfterClientHelloMessageEvent = procedure (Sender: TObject; var Cancel: boolean) of object;
property AfterClientHello: TScAfterClientHelloMessageEvent;
Occurs after receiving a "Client Hello" message from the client during the TLS/SSL handshake when starting a new session.
A handler of this event can verify the list of ClientHelloExtensions.
If the received extensions or any other properties do not comply with the server requirements, the session may be closed by setting the Cancel parameter to False.