The Freak Attack SSL/TLS Vulnerability

Post by FeeTinesAMady » Wed, Mar 04, 2015, 7:32 AM UTC

Animats wrote: post #42

OpenSSL has way too many options that reduce security. A lot of that legacy code needs to be removed outright. Not turned off by some flag, not controlled by some environment variable, removed . (And then, when Rust settles down, OpenSSL needs to be rewritten in Rust, as cleanly as possible.)

Post by sureshv » Wed, Mar 04, 2015, 8:03 AM UTC

onyxraven wrote: post #28

Amazon already updated their ELB policies to disable RC4 https://forums.aws.amazon.com/ann.jspa?annID=2877

Post by diafygi » Wed, Mar 04, 2015, 8:32 AM UTC

teekert wrote: post #84

nodesocket wrote: post #32

We wrote a blog post: The perfect SSL nginx configuration ( http://blog.commando.io/the-perfect-nginx-ssl-configuration/ ) which details all the nginx directives to set to achieve an A+ rating on sslLabs, including mitigation of FREAK, POODLE, and HEARTBLEED.

Hmm, as a novice, capable of setting up fine Drupal/Nginx/mail(Postfix) server I'm kind of shocked to get an F rating on ssllabs with the default, up to date, ssl enabled, Debian/Nginx config... Sounds like something to fix, not? Is there that much need for some forms of backwards compatibility? Are A+ servers badly reachable from older browsers or something? Why would the default be so bad? Somehow, in all my naivet…

    ssl on;
    ssl_certificate my_ssl.crt;
    ssl_certificate_key my_ssl.key;
    ssl_session_timeout 5m;
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    ssl_ciphers EECDH+aRSA+AES256:EDH+aRSA+AES256:EECDH+aRSA+AES128:EDH+aRSA+AES128;
    ssl_session_cache shared:SSL:50m;
    ssl_prefer_server_ciphers on;
    add_header Strict-Transport-Security max-age=63072000;

Post by wolf550e » Wed, Mar 04, 2015, 8:47 AM UTC

nuxi7 wrote: post #64

nodesocket wrote: post #35

Earlier quoted context omitted.

Didn't know about setting DH parameters. On each server, do the following: sudo openssl dhparam -out /etc/nginx/ssl/dhparam.pem 2048 Then in nginx.conf set: http { ssl_dhparam /etc/nginx/ssl/dhparam.pem; }

Non-EC DHE is basically dead. The param size isn't part of the TLS handshake and so using a larger size actually breaks some clients that only do 1024-bit DH params. At the end of the day, almost all the clients that support larger DH param sizes also support ECDHE, which is faster anyway. You might as well not bother and just keep a few non-PFS ciphers for those clients to avoid interoperability problems. Bonus triv…

Post by yuhong » Wed, Mar 04, 2015, 9:04 AM UTC

skuhn wrote: post #88

wolf550e wrote: post #87

Earlier quoted context omitted.

2048 bit DHE breaks java 6, but is only PFS option for recent msie on windows. A tradeoff worth making.

Well, DHE is the only PFS option for IE on Windows XP. Vista, 7 and 8 all support ECDHE. IE8 on XP is basically totally busted: https://www.ssllabs.com/ssltest/viewClient.html?name=IE&vers...