Subject: Re: [TLS] I-D Action: draft-ietf-tls-negotiated-ff-dhe-10.txt

From: "Dave Kern" <[email-masked]>
Date: Thu, 4 Jun 2015 13:51:33 -0400

>
> Please show me an HTTPS server I can point my DHE-enabled Java 6 and 7
> clients at and have them successfully negotiate a TLS session. I dare 
you.

I'll rise to the bait. Point your Java client at any current IBM Domino 
server that is configured according to the current recommendations:
 
http://www-10.lotus.com/ldd/dominowiki.nsf/dx/TLS_Cipher_Configuration
 
The only DHE cipher supported by Java 6 and 7 is 
TLS_DHE_RSA_WITH_AES_128_CBC_SHA (0x0033), 
so as long as that one cipher is not enabled Java 6 and 7 will probably 
end up with something they can handle, such as 
TLS_RSA_WITH_AES_128_CBC_SHA (0x002F) 
and modern clients will end up with a stronger DHE-RSA cipher.
 
We also have changes in the current development stream to prioritize 
0x0033 below 0x002F as the last of the AES ciphers -- submitted 
post-Logjam -- and to always use a 1024 bit DH group with 0x0033 
instead of the (default or configured) stronger DH group -- submited 
pre-Logjam but left in place because being potentially vulnerable to 
Three Letter Agencies is still better than failing the handshake and 
transmitting data in the clear.
 
Servers *can* provide strong DHE groups to modern browsers and avoid 
loss of compatibility with Java 6 and 7, and it's not even that much 
work to do so.
 
Hope that helps,
 
dave

---

From: Tony Arcieri <[email-masked]>
Date: Thu, 4 Jun 2015 18:03:15 -0700

On Thu, Jun 4, 2015 at 10:51 AM, Dave Kern <[email-masked]> wrote:

> I'll rise to the bait.

Thanks for taking my challenge, and mea culpa for being wrong.

-- 
Tony Arcieri