httpd-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Joe Orton <>
Subject Re: TLS renegotiation attack, mod_ssl and OpenSSL
Date Thu, 05 Nov 2009 21:31:00 GMT
On Thu, Nov 05, 2009 at 09:38:23PM +0100, Ruediger Pluem wrote:
> If server triggered renegotiation will not work at all, people will just ignore the
> update or remove it from 0.9.8l in their self patched versions.
> So overall I guess we would be safer with an approach that
> 1. Turns off renegotiation (server and client) by default.
> 2. Allows to turn on server and client triggered renegotiation in a way as proposed
>    by Joe.
> 3. Allow to turn on server triggered renegotiation by a compile time option.

In discussion here, Theo Schlossnagle has suggested (and implemented for 
another SSL server) an approach for (2) which I think we can use for 
mod_ssl, and doesn't require patching OpenSSL:

* we can detect in mod_ssl when the client is renegotiating by using the 
callback installed using SSL_CTX_set_info_callback(), in conjunction 
with suitable flags in the SSLConnRec to detect the cases where this is 
either a server-initiated renegotiation or the initial handshake on the 

I'll try a patch for this.

Regards, Joe

View raw message