Re: DH_check return value test correct?

On Fri, May 12, 2006 at 06:39:44PM -0400, Tom Lane wrote:
> Michael Fuhr <mike(at)fuhr(dot)org> writes:
> > If $PGDATA/dh1024.pem exists and if SSL connections are enabled,
> > then each SSL connection logs the following:
> > DH_check error (dh1024.pem): No SSL error reported
> > The backend then loads the hardcoded parameters. The SSL connection
> > works, but with DH parameters other than intended.
>
> So it's not that surprising that no one noticed it was broken :-(

Incidentally, is it necessary to load the DH parameters anew and
call DH_check for every connection? The parameters don't change
and DH_check is fairly expensive: checking a 1024-bit parameter on
a 500MHz Pentium III takes about 260ms, which can be a significant
portion of the SSL handshake. The expense is probably negligible
on fast hardware but on older systems it makes connect times
noticeably slow (one of my test boxes is a 143MHz sparc Ultra 1;
DH_check takes almost 2 sec).

--
Michael Fuhr