oss-sec mailing list archives

Re: openssl default ciphers


From: Daniel Kahn Gillmor <dkg () fifthhorseman net>
Date: Mon, 04 Nov 2013 12:36:16 -0500

On 11/04/2013 12:16 PM, Stefan Bühler wrote:

while working on the lighttpd SNI bug I realized that openssl defaults
to a very bad set of ciphers.

I also couldn't find a sane recommendation from upstream openssl to use
as default, as "DEFAULT" obviously is not a good choice. (I also don't
see any reason why "DEFAULT" includes export and "LOW" ciphers...)

Is 'DEFAULT@STRENGTH:!LOW:!EXP' (should
be similar to 'HIGH:MEDIUM:!aNULL') a reasonably default?

I don't want to enforce PFS or break compatibility on purpose; so I
think the default could be a little bit less "secure" than what I would
actually recommend to use.

So I'm not interested in how to get a super extra secure cipher set
(there are many cipher strings in the wild by various folks for that),
but more in a reasonable lower bound.

There is ongoing discussion on one of the major users of OpenSSL (apache) about what the defaults should be for that user:

 https://issues.apache.org/bugzilla/show_bug.cgi?id=49559#c11

I agree that the OpenSSL defaults seem too lax.

        --dkg


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