[PATCH 1/1] tpm: fixed the nv_define_space command in TPMv2

[Ilias Apalodimas]

Hi Michel,

On Thu, 20 Feb 2025 at 09:14, Michel Alex
<Alex.Michel at wiedemann-group.com> wrote:
>
> Hi Ilias,
>
> I don't know where to find the spec for the tpm v2 nv_define command. I was just wondering
> why this command does not work in u-boot. Then I found a patch, that has never been
> applied to the master, see https://lists.denx.de/pipermail/u-boot/2023-December/542089.html,

Yes, that patch was useful but unfortunately, it didn't apply to
-master cleanly and I haven't seen an updated revision since.
I'll have a look at the tpm specs and figure out why this change is
working and let you know. You can then send a v2 with a commit message
that explains why

Thanks
/Ilias

> where the nv_define's message buf was "fixed". I tried this change and the nv_define command
> is working now.
>
> Alex
>
> > -----Original Message-----
> > From: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> > Sent: Tuesday, February 18, 2025 8:38 AM
> > To: Michel Alex <Alex.Michel at wiedemann-group.com>
> > Cc: u-boot at lists.denx.de
> > Subject: Re: [PATCH 1/1] tpm: fixed the nv_define_space command in TPMv2
> >
> > Vorsicht: Es handelt sich um eine externe E-Mail vom Absender Ilias
> > Apalodimas <ilias.apalodimas at linaro.org>. Bitte klicken Sie nicht auf Links oder
> > Anhänge, solange Sie nicht von der Echtheit der Nachricht überzeugt sind.
> >
> > Hi Michel
> >
> > On Thu, Feb 13, 2025 at 12:43:34PM +0000, Michel Alex wrote:
> > > Added 2 HMAC bytes to the command message
> >
> > Please cc the TPM maintainers, otherwise I might miss this patch.
> >
> > What the patch does is obvious, can you add a better explanation of
> > - what it fixes / what was broken?
> > - pointers to spec that define the hmac size and placement?
> >
> > Thanks
> > /Ilias
> > >
> > > Signed-off-by: Alex Michel <alex.michel at wiedemann-group.com>
> > > ---
> > >  lib/tpm-v2.c | 5 +++--
> > >  1 file changed, 3 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index
> > > 9ca7933c094..4a082af78af 100644
> > > --- a/lib/tpm-v2.c
> > > +++ b/lib/tpm-v2.c
> > > @@ -264,7 +264,7 @@ u32 tpm2_nv_define_space(struct udevice *dev, u32
> > space_index,
> > >      * chunks below.
> > >      */
> > >     const int platform_len = sizeof(u32);
> > > -   const int session_hdr_len = 13;
> > > +   const int session_hdr_len = 15;
> > >     const int message_len = 14;
> > >     uint offset = TPM2_HDR_LEN + platform_len + session_hdr_len +
> > >             message_len;
> > > @@ -277,11 +277,12 @@ u32 tpm2_nv_define_space(struct udevice *dev, u32
> > space_index,
> > >             /* handles 4 bytes */
> > >             tpm_u32(TPM2_RH_PLATFORM),      /* Primary platform seed */
> > >
> > > -           /* session header 13 bytes */
> > > +           /* session header 15 bytes */
> > >             tpm_u32(9),                     /* Header size */
> > >             tpm_u32(TPM2_RS_PW),            /* Password authorisation
> > */
> > >             tpm_u16(0),                     /* nonce_size */
> > >             0,                              /* session_attrs */
> > > +           tpm_u16(0),                     /* HMAC size */
> > >             tpm_u16(0),                     /* auth_size */
> > >
> > >             /* message 14 bytes + policy */
> > > --
> > > 2.43.0
> > >