Re: SSL: better default ciphersuite - Mailing list pgsql-hackers

From Peter Eisentraut
Subject Re: SSL: better default ciphersuite
Date
Msg-id 1385734729.27340.13.camel@vanquo.pezone.net
Whole thread Raw
In response to SSL: better default ciphersuite  (Marko Kreen <markokr@gmail.com>)
Responses Re: SSL: better default ciphersuite  (Marko Kreen <markokr@gmail.com>)
List pgsql-hackers
On Fri, 2013-11-15 at 01:11 +0200, Marko Kreen wrote:
> Attached patch changes the default ciphersuite to
> 
>     HIGH:!aNULL
> 
> instead of old
> 
>     DEFAULT:!LOW:!EXP:!MD5:@STRENGTH
> 
> where DEFAULT is a shortcut for "ALL:!aNULL:!eNULL".

> Main goal is to leave low-level ciphersuite details to OpenSSL guys
> and give clear impression to Postgres admins what it is about.

If we want to leave the details of the ciphers to OpenSSL, I think we
shouldn't be second-guessing their judgement of what a reasonable
default is.

I checked Apache mod_ssl and Postfix, and even though they are
configuring this slightly differently, I think their defaults end up
being about the same as what PostgreSQL currently has.

https://httpd.apache.org/docs/2.4/mod/mod_ssl.html#sslciphersuite
http://www.postfix.org/postconf.5.html#smtpd_tls_mandatory_ciphers

> HIGH:
>   Contains only secure and well-researched algorithms.
> 
> !aNULL
>   Needed to disable suites that do not authenticate server.
>   DEFAULT includes !aNULL by default.

Wouldn't HIGH exclude aNULL also?  (If not, what about eNULL?)

> !MD5
>   This affects only one suite: DES-CBC3-MD5, which is available only
>   for SSL2 connections.  So it would only pollute the default value.

I think this is only there for political correctness.

> @STRENGTH
>   The OpenSSL cipher list is already sorted by humans,
>   it's unlikely that mechanical sort would improve things.
>   Also the existence of this value in old list is rather
>   dubious, as server cipher order was never respected anyway.

Aren't you proposing to change that?





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