22-Oct-2021 08:40
Hello, I have the cipher suite configured in my parent client-ssl profile:
!ECDH_RSA:!ECDH_ECDSA:!SHA:-AES:AES:ECDHE:ECDHE_ECDSA:DHE:DHE_DSS:!RSA
How can I only provide ONLY 256 bits ciphers and remove all 128?
Do I need to name them or is there a way to commit them in the string?
Thank you
Julio
17-Nov-2021 05:58
Hello Julio,
first things first, I would recommend not to edit default SSL profiles: instead, create a new one and inherit settings from defaults.
You can filter ciphers by strength with keywords LOW (64 bit bulk crypto algorithm) , MEDIUM (128-bit) and HIGH ( [ 168 bit/192 bit -- deprecated] and 256-bit ).
So your default string should be HIGH , and then exclude unwanted suites.
You can test output with command tmm --clientciphers <string> , ex. tmm --clientciphers "HIGH" or tmm --clientciphers "HIGH:!ECDH_RSA:!ECDH_ECDSA:!SHA:!RSA"
18-Nov-2021 07:50
That's good info. With "@STRENGTH" one can have the cipher negotiation start with the strongest cipher and progress to the weakest (example: DEFAULT:!3DES:!DHE:!RC4:!RSA:@STRENGTH)
This is just for anyone who may have a need for it. 😀