Distributed Denial of Service (DDoS) protection is not a feature of Firepower Threat Defense, no matter what subscription level. Generally we look to external services (i.e. from your ISP or a third party) for such protection.
On the very high end Firepower 4100 and 9300 series platforms we can optionally add an instance of Radware Virtual Defense Pro which does provide DDoS protection.
Your second question is unclear. What are you asking about SSL encryption? SSL decryption is supported on all Firepower platforms but undertaking it on any significant scale requires a lot of processing power and comes with significant caveats.It 's usually easier to accomplish the organizational security goal via another method (or set of methods) such as endpoint protection (like Cisco AMP) and a secure Internet Gateway (like Cisco Umbrella).
