Welcome! Log In Create A New Profile

Advanced

Re: "A" Grade SSL/TLS with Nginx and StartSSL

W-Mark Kubacki
October 20, 2013 05:14PM
2013-10-15 Piotr Sikora <piotr@cloudflare.com>
has cited Julien Vehent <julien@linuxwall.info>:
>
> ssl_ciphers 'ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:ECDHE-RSA-RC4-SHA:ECDHE-ECDSA-RC4-SHA:RC4-SHA:HIGH:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK';

Why did you sort the ciphers in this particular order?

If you wanted to prefer AES128 over AES256 over RC4 you could write:
# ssl_ciphers 'AES128:AES256:RC4+SHA:!aNULL:!PSK:!SRP';
See the output of:
# openssl ciphers list -v 'AES128:AES256:RC4+SHA:!aNULL:!PSK'
OpenSSL will order the combinations by strength and include new modes
by default.

Why do you include the weak RC4?
You don't use SSLv3. The subset of outdated clients not able to
use TLSv1.1 *and* AES properly is diminishing. (They would have been
not been patched for about more than two years and need to repeatedly
(think: millions of times) request the same binary data without Nginx
changing the response…)

Given that AES256 boils down to 2**99.5 bits attack (time/step)
complexity [1] and AES128 to 2**100 if you agree with [2] I would
suggest this:
# ssl_ciphers 'AES128:!aNULL:!PSK:!SRP'
… Include PSK and/or SRP if you need them, which almost none webserver
operator does. Optionally with !ECDH if you don't trust the origin of
the random seed values for NIST curves.

--
Mark
http://mark.ossdl.de/

[1] http://eprint.iacr.org/2009/317
[2] http://eprint.iacr.org/2002/044

_______________________________________________
nginx mailing list
nginx@nginx.org
http://mailman.nginx.org/mailman/listinfo/nginx
Subject Author Posted

"A" Grade SSL/TLS with Nginx and StartSSL

Julien Vehent October 12, 2013 05:56PM

Re: "A" Grade SSL/TLS with Nginx and StartSSL

Piotr Sikora October 15, 2013 12:40AM

Re: "A" Grade SSL/TLS with Nginx and StartSSL

Julien Vehent October 15, 2013 09:28AM

Re: "A" Grade SSL/TLS with Nginx and StartSSL

Piotr Sikora October 15, 2013 06:02PM

Re: "A" Grade SSL/TLS with Nginx and StartSSL

Rob Stradling October 17, 2013 10:06AM

Re: "A" Grade SSL/TLS with Nginx and StartSSL

W-Mark Kubacki October 20, 2013 05:14PM

Re: "A" Grade SSL/TLS with Nginx and StartSSL

eiji-gravion October 16, 2013 10:22PM



Sorry, only registered users may post in this forum.

Click here to login

Online Users

Guests: 62
Record Number of Users: 6 on February 13, 2018
Record Number of Guests: 421 on December 02, 2018
Powered by nginx      Powered by FreeBSD      PHP Powered      Powered by MariaDB      ipv6 ready