I'm looking for web server (nginx) configuration that support current (Nov 2015) PCI-DSS requrements about SSL:
- No TLSv1.0 (only TLSv1.1 and TLSv1.2, and TLSv1.3 in the future).
- No weak ssl ciphers, it means no CBC (Cipher Block Chaining), no DES, IDEA Cipher Suites, no RC4 etc.
After many scans using Nexpose I created Nginx configuration, that fnally meet this very restrictive requirements. My current test config looks like this:
server {
#(..)
ssl_certificate asdf.crt;
ssl_certificate_key sadf.key;
ssl_protocols TLSv1.1 TLSv1.2; #see about TLSv1.1 below
ssl_ecdh_curve secp521r1;
ssl_prefer_server_ciphers on;
ssl_session_cache shared:SSL:10m;
ssl_session_timeout 5m;
ssl_dhparam asdf-dh2048.pem; #sorry, no support for Java 6u45
ssl_ciphers #ssh_ciphers of course should be in one line
ECDHE-ECDSA-AES256-GCM-SHA384:
ECDHE-ECDSA-AES128-GCM-SHA256:
ECDHE-RSA-AES256-GCM-SHA384:
ECDHE-RSA-AES128-GCM-SHA256:
DHE-RSA-AES256-GCM-SHA384:
DHE-RSA-AES128-GCM-SHA256:
AESGCM:
!aNULL:!eNULL:!EXPORT:!RC4:!MD5:!PSK;
}
Unfortunately:
- There are only 7 ssl_ciphers, and generally used are only first 6.
- Even if I enable TLSv1.1 it doesn't mather, the ciphers above are available only in TLSv1.2.
- Scan using https://www.ssllabs.com/ssltest show that website has A+ grate (great!) but also show, that many (or most) of browser and libraries will be not able to connect due to "Protocol or cipher suite mismatch" (not working: IE 6-10, Java 6 and 7, Android 2.3-4.4, OpenSSL 0.9.8, Safari 5-8, etc).
- I removed TLSv1.0 so there is no option to conect using apps installed on Win XP, Win Vista, Win Serv 2003, I know.
- Scan using Nexpose show no problem (i.ed. no CBC in use, etc).
Nginx use openssl, so according to https://www.openssl.org/docs/manmaster/apps/ciphers.html (chapter "CIPHER SUITE NAMES" in the middle of page) after removing CBC,RC4 and other "weak" elements, I don't see any option to use TLSv1.0 or TLSv1.1 protocols. I don't see also possibilities to use TLSv1.2 with more ciphers.
Does anybody have idea, what in my config can be changed, for increasing compatibility with browsers/libraries/systems, and still be PCI-DSS compliant?
