RE: [EXT] Re: [PATCH v5 3/5] KEYS: trusted: allow trust sources to use kernel RNG for key material

[Pankaj Gupta]

Acked-by: Pankaj Gupta <pankaj.gupta@xxxxxxx>

Regards
Pankaj

> -----Original Message-----
> From: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> Sent: Wednesday, February 23, 2022 9:53 PM
> To: James Bottomley <jejb@xxxxxxxxxxxxx>; Jarkko Sakkinen
> <jarkko@xxxxxxxxxx>; Mimi Zohar <zohar@xxxxxxxxxxxxx>; David Howells
> <dhowells@xxxxxxxxxx>
> Cc: kernel@xxxxxxxxxxxxxx; Sumit Garg <sumit.garg@xxxxxxxxxx>; David Gstir
> <david@xxxxxxxxxxxxx>; tharvey@xxxxxxxxxxxxx; James Morris
> <jmorris@xxxxxxxxx>; Serge E. Hallyn <serge@xxxxxxxxxx>; Horia Geanta
> <horia.geanta@xxxxxxx>; Aymen Sghaier <aymen.sghaier@xxxxxxx>;
> Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>; David S. Miller
> <davem@xxxxxxxxxxxxx>; Eric Biggers <ebiggers@xxxxxxxxxx>; Jan Luebbe
> <j.luebbe@xxxxxxxxxxxxxx>; Richard Weinberger <richard@xxxxxx>; Franck
> Lenormand <franck.lenormand@xxxxxxx>; Matthias Schiffer
> <matthias.schiffer@xxxxxxxxxxxxxxx>; Pankaj Gupta
> <pankaj.gupta@xxxxxxx>; keyrings@xxxxxxxxxxxxxxx; linux-
> crypto@xxxxxxxxxxxxxxx; linux-integrity@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; linux-security-module@xxxxxxxxxxxxxxx
> Subject: [EXT] Re: [PATCH v5 3/5] KEYS: trusted: allow trust sources to use
> kernel RNG for key material
> 
> Caution: EXT Email
> 
> On 22.02.22 20:58, Ahmad Fatoum wrote:
> > The two existing trusted key sources don't make use of the kernel RNG,
> > but instead let the hardware that does the sealing/unsealing also
> > generate the random key material. While a previous change offers users
> > the choice to use the kernel RNG instead for both, new trust sources
> > may want to unconditionally use the kernel RNG for generating key
> > material, like it's done elsewhere in the kernel.
> >
> > This is especially prudent for hardware that has proven-in-production
> > HWRNG drivers implemented, as otherwise code would have to be
> > duplicated only to arrive at a possibly worse result.
> >
> > Make this possible by turning struct trusted_key_ops::get_random into
> > an optional member. If a driver leaves it NULL, kernel RNG will be
> > used instead.
> 
> The rebase on the change in scope of the previous commit made this one
> here quite small. I would squash it into the previous commit for v6, unless
> there are objections.
> 
> 
> >
> > Acked-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
> > Reviewed-by: David Gstir <david@xxxxxxxxxxxxx>
> > Tested-By: Tim Harvey <tharvey@xxxxxxxxxxxxx>
> > Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> > ---
> > To: James Bottomley <jejb@xxxxxxxxxxxxx>
> > To: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> > To: Mimi Zohar <zohar@xxxxxxxxxxxxx>
> > To: David Howells <dhowells@xxxxxxxxxx>
> > Cc: James Morris <jmorris@xxxxxxxxx>
> > Cc: "Serge E. Hallyn" <serge@xxxxxxxxxx>
> > Cc: "Horia Geantă" <horia.geanta@xxxxxxx>
> > Cc: Aymen Sghaier <aymen.sghaier@xxxxxxx>
> > Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> > Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> > Cc: Eric Biggers <ebiggers@xxxxxxxxxx>
> > Cc: Jan Luebbe <j.luebbe@xxxxxxxxxxxxxx>
> > Cc: David Gstir <david@xxxxxxxxxxxxx>
> > Cc: Richard Weinberger <richard@xxxxxx>
> > Cc: Franck LENORMAND <franck.lenormand@xxxxxxx>
> > Cc: Sumit Garg <sumit.garg@xxxxxxxxxx>
> > Cc: Tim Harvey <tharvey@xxxxxxxxxxxxx>
> > Cc: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx>
> > Cc: Pankaj Gupta <pankaj.gupta@xxxxxxx>
> > Cc: keyrings@xxxxxxxxxxxxxxx
> > Cc: linux-crypto@xxxxxxxxxxxxxxx
> > Cc: linux-integrity@xxxxxxxxxxxxxxx
> > Cc: linux-kernel@xxxxxxxxxxxxxxx
> > Cc: linux-security-module@xxxxxxxxxxxxxxx
> > ---
> >  include/keys/trusted-type.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
> > index d89fa2579ac0..4eb64548a74f 100644
> > --- a/include/keys/trusted-type.h
> > +++ b/include/keys/trusted-type.h
> > @@ -64,7 +64,7 @@ struct trusted_key_ops {
> >       /* Unseal a key. */
> >       int (*unseal)(struct trusted_key_payload *p, char *datablob);
> >
> > -     /* Get a randomized key. */
> > +     /* Optional: Get a randomized key. */
> >       int (*get_random)(unsigned char *key, size_t key_len);
> >
> >       /* Exit key interface. */
> 
> 
> --
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