NSExceptionRequiresForwardSecrecy
A Boolean value indicating whether to override the perfect forward secrecy requirement.
Discussion
Set the value for this key to NO to override the requirement that a server support perfect forward secrecy (PFS) for the given domain. Disabling this requirement also removes the key length check described in Ensure the Network Server Meets Minimum Requirements. However, it doesn’t impact the TLS version requirement. To control that, use NSExceptionMinimumTLSVersion.
This key is optional. The default value is YES, which limits the accepted ciphers to those that support PFS through Elliptic Curve Diffie-Hellman Ephemeral (ECDHE) key exchange.