Not able to block a specific TLS1.3 cipher

[Alan DeKok]

On Apr 24, 2025, at 6:29 AM, Akhil Pillai <akhilpillai101 at gmail.com> wrote:
> 
> I have been trying to use only a specific tls1.3 cipher but it fails.  I
> want to use only SHA256.  Below is the debug out.
> ...
> tls: (TLS) Failed setting cipher list: error:0A0000B9:SSL routines::no
> cipher match
> rlm_eap_tls: Failed initializing SSL context
> rlm_eap (EAP): Failed to initialise rlm_eap_tls
> /etc/freeradius3/mods-enabled/eap[14]: Instantiation failed for module "eap"
> 
> Any idea why this fails?

  This is an error from OpenSSL.  It means that there is no such cipher as "TLS_AES_128_GCM_SHA256"

  See the OpenSSL documentation for a list of what ciphers it supports.

  Alan DeKok.