So there are some news from the front of OpenSSL CVE-2009-3555 (see this and this for the history).
Now the latest version of Apache mod_ssl (2.2) embeds an option to reactivate old way client renegociation :
Check the official doc for more details. With this option activated, you can now safely upgrade openSSL and mod_ssl without breaking your clients. They should have done it from the begining, shouldn’t they ?
The next step will be to move on to the new protocol definitely, to solve for good the CVE-2009-3555 vulnerability. For that we have to wait for the browsers to support it.
Firefox has started to work seriously on it and we can expect some support in the next releases (some settings will be possible through about:config).
They even created a test site. This screenshot was taken from Google Chrome (5.0.366.2, openSUSE repo) which already has support for the SSL protocol :
A solution has been finally brought up to fix CVE-2009-3555 and the temporary solution that broke client authentication.
At least, the IETF agreed on a fix as Marsh Ray informs us, though it will still take some weeks for the whole validation process to complete.
Moreover, as it requires both the servers and the clients to be patched, it will take months before the patches can be applied and one can have a working client authentification architecture. The longest will be the client side, of course, so I feel sorry for those who have a large park to manage.
As far as I am concerned, fortunately, I will just have a few browsers that I manage directly to update. Anyway, still more patience is needed !