I need to analyze the http logs to make sure every single HTTP request is using at least TLSv1.3 but I can't configured such access log pattern. I can at best configure my pattern like this :

%H %t %a "%r" %s %b (%D ms) %{SSL_CIPHER} %{SSL_SESSION_ID}

But I would like to add SSL_PROTOCOL :

%H %t %a "%r" %s %b (%D ms) %{SSL_PROTOCOL} %{SSL_CIPHER} %{SSL_SESSION_ID}

To easily grep for TLS version in my logs

grep TLSv undertow-http.log

HTTP/2.0 [11/Dec/2020:16:28:51 -0500] 192.168.0.1 "POST /undertow/api/my-service HTTP/2.0" 200 - (5598 ms) TLSv1.3 TLS_AES_256_GCM_SHA384 jncSMtjKnBDH008SpvdfgGyjsBZnCmUuwVLoSoWc+ek=

Looking at doc here I can't find anything relevant :

https://undertow.io/undertow-docs/undertow-docs-2.1.0/predicates-attributes-handlers.html