Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 20 Jul 2008 21:39:55 +0200
From:      Pawel Jakub Dawidek <pjd@FreeBSD.org>
To:        Patrick Lamaizi?re <patfbsd@davenulle.org>
Cc:        freebsd-hackers@freebsd.org
Subject:   Re: crypto(9) and maxoplen
Message-ID:  <20080720193955.GA2193@garage.freebsd.pl>
In-Reply-To: <20080719005813.3a995c71@baby-jane-lamaiziere-net.local>
References:  <20080719005813.3a995c71@baby-jane-lamaiziere-net.local>

next in thread | previous in thread | raw e-mail | index | archive | help

--fdj2RfSjLxBAspz7
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Sat, Jul 19, 2008 at 12:58:13AM +0200, Patrick Lamaizi?re wrote:
> Hello,
>=20
> In the "opencrypto framework" the function crypto_register() has an
> argument 'maxoplen'.
>=20
> http://fxr.watson.org/fxr/source/opencrypto/crypto.c#L625
>=20
> Does somebody know what was the goal of this parameter? It is not used
> by the framework.
>=20
> The man page of crypto(9) says :
> For each algorithm the driver supports, it must then call
> crypto_register(). The first two arguments are the driver and algorithm
> identifiers.  The next two arguments specify the largest possible
> operator length (in bits, important for public key operations) and
> flags for this algorithm.
>=20
> I'm asking if it can help for this problem: the glxsb driver can
> perform AES-CBC algorithm only with 128 bits key and may be 'maxoplen'
> was intended for this case.=20
>=20
> Without something to specify the key's length, the driver is selected
> by the framework even with keys !=3D 128 bits. So it fails when the
> session is opened. This prevents setkey/ipsec to work with key
> length !=3D 128 bits if the driver is loaded.

If I read code properly, there is currently no way for a driver to say
to the opencrypto framework that only AES-CBC with 128bit key is
supported. A driver can only state that it supports AES-CBC, that's all.
As a workaround the driver should implement AES-CBC-192 and AES-CBC-256
in software.

--=20
Pawel Jakub Dawidek                       http://www.wheel.pl
pjd@FreeBSD.org                           http://www.FreeBSD.org
FreeBSD committer                         Am I Evil? Yes, I Am!

--fdj2RfSjLxBAspz7
Content-Type: application/pgp-signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.4 (FreeBSD)

iD8DBQFIg5SLForvXbEpPzQRAuEvAKCjES6hgBVSR/qJeVMOz0h0YiT3cwCg6+Wa
gMkp5jnBTg6qASgC2kmkIoY=
=+YiR
-----END PGP SIGNATURE-----

--fdj2RfSjLxBAspz7--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20080720193955.GA2193>