Received-SPF: pass (google.com: domain of linux-crypto-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Message-ID: <7c2b6eff291b2d326e96c3a5f9cd70aa4ef92df3.camel@chronox.de>
Subject: Re: [PATCH net-next] [RESEND] wireguard: disable in FIPS mode
From:   Stephan Mueller <smueller@chronox.de>
To:     Hangbin Liu <liuhangbin@gmail.com>,
        Eric Biggers <ebiggers@kernel.org>
Cc:     netdev@vger.kernel.org, "Jason A . Donenfeld" <Jason@zx2c4.com>,
        Toke =?ISO-8859-1?Q?H=F8iland-J=F8rgensen?= <toke@redhat.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Ondrej Mosnacek <omosnace@redhat.com>,
        linux-crypto@vger.kernel.org
Date:   Fri, 09 Apr 2021 09:08:20 +0200
In-Reply-To: <20210409021121.GK2900@Leo-laptop-t470s>
References: <20210407113920.3735505-1-liuhangbin@gmail.com>
         <YG4gO15Q2CzTwlO7@quark.localdomain>
         <20210408010640.GH2900@Leo-laptop-t470s>
         <20210408115808.GJ2900@Leo-laptop-t470s> <YG8dJpEEWP3PxUIm@sol.localdomain>
         <20210409021121.GK2900@Leo-laptop-t470s>
Content-Type: text/plain; charset="UTF-8"
User-Agent: Evolution 3.38.4 (3.38.4-1.fc33) 
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Am Freitag, dem 09.04.2021 um 10:11 +0800 schrieb Hangbin Liu:
> On Thu, Apr 08, 2021 at 08:11:34AM -0700, Eric Biggers wrote:
> > On Thu, Apr 08, 2021 at 07:58:08PM +0800, Hangbin Liu wrote:
> > > On Thu, Apr 08, 2021 at 09:06:52AM +0800, Hangbin Liu wrote:
> > > > > Also, couldn't you just consider WireGuard to be outside your FIPS
> > > > > module
> > > > > boundary, which would remove it from the scope of the certification?
> > > > > 
> > > > > And how do you handle all the other places in the kernel that use
> > > > > ChaCha20 and
> > > > > SipHash?  For example, drivers/char/random.c?
> > > > 
> > > > Good question, I will check it and reply to you later.
> > > 
> > > I just read the code. The drivers/char/random.c do has some fips
> > > specific
> > > parts(seems not related to crypto). After commit e192be9d9a30 ("random:
> > > replace
> > > non-blocking pool with a Chacha20-based CRNG") we moved part of chacha
> > > code to
> > > lib/chacha20.c and make that code out of control.
> > > 
> > So you are saying that you removed drivers/char/random.c and
> > lib/chacha20.c from
> > your FIPS module boundary?  Why not do the same for WireGuard?
> 
> No, I mean this looks like a bug (using not allowed crypto in FIPS mode) and
> we should fix it.

The entirety of random.c is not compliant to FIPS rules. ChaCha20 is the least
of the problems. SP800-90B is the challenge. This is one of the motivation of
the design and architecture of the LRNG allowing different types of crypto and
have a different approach to post-process the data.

https://github.com/smuellerDD/lrng

Ciao
Stephan
> 
> Thanks
> Hangbin