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EDH requirement in PFS?

Question asked by Joshua Small on Sep 8, 2013
Latest reply on Sep 9, 2013 by Joshua Small

Hi, I'm running an nginx built with EC support, and started with this string:
ssl_ciphers "EECDH+ECDSA+AESGCM EECDH+aRSA+AESGCM EECDH+ECDSA+SHA384 EECDH+ECDSA+SHA256 EECDH+aRSA+SHA384 EECDH+aRSA+SHA256 EECDH+aRSA+RC4 EECDH EDH+aRSA RC4 !aNULL !eNULL !LOW !3DES !MD5 !EXP !PSK !SRP !DSS +RC4 RC4";
There, I see a big green "This server supports Forward Secrecy". However, I'm seeing an 80% on the "Key Exchange". I understand this is due to the "EDH+aRSA" section, so tested removing it.
Following this, the test now reports my "Key exchange" as 90% (good, now if only a CA supported 4096bit keys/roots). However, I lose the "This server supports Forward secrecy" section and "Forward secrecy" section down the bottom now lists an orange "NO" without DHE. The "Handshake simulation" still appears to suggest FS was negotiated in the majority of FS supporting browsers, and a common consensus appears to be that PFS isn't worth the performance hit without EC (Maybe I didn't look hard enough but I couldn't see any changes to the browser support for FS in between these configurations)
Wouldn't it be enough to suggest forward secrecy is supported if it's only supported with EC, particularly when this configuration only appears to push the rating up (forgetting about the BEAST cap at B for the moment).

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