On Fri, Jun 11, 2021 at 06:48:09PM -0600, Shawn Heisey wrote:
> I'm fiddling with ssl labs to see how I can improve my TLS setup.
>
> Here's what they say about a site I have behind haproxy with TLS:
>
> https://www.elyograg.org/foo/haproxy-ssllabs-session-resumption-not-working.png
>
> They claim that session resumption isn't working. I'm hoping that I've just
> done something wrong... which will be bad for my ego but great for getting
> problems fixed. I did have the option to disable tls tickets, but when I
> took it out, my ssl labs grade didn't go down, so it's still not there.
>
> This is what I have in the global section:
>
> global
> log 127.0.0.1 len 65535 format rfc5424 local0
> log 127.0.0.1 len 65535 format rfc5424 local1 notice
> maxconn 4096
> daemon
> spread-checks 2
> tune.bufsize 65536
> tune.http.logurilen 49152
> tune.ssl.cachesize 100000
> tune.ssl.lifetime 900
> ssl-server-verify none
> tune.ssl.default-dh-param 2048
> ssl-default-bind-ciphers EECDH+AESGCM:EDH+AESGCM
> ssl-default-bind-options no-sslv3 no-tlsv10 no-tlsv11
> ssl-default-server-ciphers
> RC4-MD5:ECDHE-RSA-AES256-SHA384:DHE-RSA-AES128-SHA:AES256-SHA:AES256-SHA256
> stats socket /etc/haproxy/stats.socket
>
> I don't think there's anything else in the config that could affect this,
> but if there is something that would help diagnose, let me know.
I don't know if the config is responsible for this but I've just tested
on haproxy.org and it does work there:
Session resumption (caching) Yes
Session resumption (tickets) Yes
Our bind line looks like this:
bind :443 ssl alpn h2,http/1.1 npn h2,http/1.1 no-sslv3 crt
... ciphers
ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:!DSS:!EDH
ecdhe prime256v1
and we don't have any ssl-default-* nor tune.ssl.* setting. Maybe you
could start bisecting among these parameters.
Willy
