SSL supports SSL session resume.
This feature saves a lot of time because SSL initialization (time consuming is skipped).
For details, please see : https://vincent.bernat.ch/en/blog/2011-ssl-session-reuse-rfc5077
I did a standalone test with Apache HttpClient having same version the one used in Camel 2.25.1 : it works.
But SSL session resuming fails with Camel.
Server Hello is rejected by Apache Web server.
Apache says :
AH02255: Changed client verification type will force renegotiation
And then previous session is invalidated.
This problem doesn't occur in my standalone tester.
Resuming SSL sessions would increase drasticaly performance.