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From Chris Hill <>
Subject Re: [users@httpd] Disabling client initiated renegotiation
Date Sun, 10 Apr 2011 00:27:23 GMT
Nothing wrong with re-negotiation if used for what it was intended. Now,
since a server cannot limit how many of these a client can request, this
leaves the doors open to abuse (DoS --not to be confused with DDoS).

To me, disabling it would be as good as limiting how many times a client can
request renegotiation.

There are actual attacks taking advantage of it, and security vendors
(IDS/IPS) are already working on ways to detect these. However, vendors are
falling behind when it comes to providing a good solution that can allow
system administrators to limit user's trying to take advantage of this.

If you are serious about this and want to provide a solution to disable
re-negotiation altogether, I would share more info on how this is being


On Sat, Apr 9, 2011 at 7:37 PM, Mark Montague <> wrote:

>  On April 9, 2011 18:00 , Chris Hill <>  wrote:
> My company relies on Apache for a number of customer facing sites. What's a
>> reliable way to disable client initiated renegotiation (both secure and
>> insecure renegotiation)?. I know one specific openssl library (l) disables
>> this, but then later ones enable "secure" renegotiation, which we need to
>> disable.
>> Ideally, I'd like a solution through an configuration parameter so that
>> future versions/upgrades do not re-enable renegotiation.
> I don't have an answer for you, but, out of curiosity, why do you need to
> disable SSL 3.0 / TLS renegotiation?  If a client initiates a renegotiation,
> is this bad in some way?  Obviously, you trusted the client during the
> initial negotiation/handshake.
> --
>  Mark Montague

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