Re: [PATCH v9 6/6] tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()

From: Mimi Zohar
Date: Fri Feb 01 2019 - 09:33:32 EST


On Fri, 2019-02-01 at 15:41 +0200, Jarkko Sakkinen wrote:
> On Fri, Feb 01, 2019 at 03:39:49PM +0200, Jarkko Sakkinen wrote:
> > On Fri, Feb 01, 2019 at 11:06:41AM +0100, Roberto Sassu wrote:
> > > Currently, tpm_pcr_extend() accepts as an input only a SHA1 digest.
> > >
> > > This patch replaces the hash parameter of tpm_pcr_extend() with an array of
> > > tpm_digest structures, so that the caller can provide a digest for each PCR
> > > bank currently allocated in the TPM.
> > >
> > > tpm_pcr_extend() will not extend banks for which no digest was provided,
> > > as it happened before this patch, but instead it requires that callers
> > > provide the full set of digests. Since the number of digests will always be
> > > chip->nr_allocated_banks, the count parameter has been removed.
> > >
> > > Due to the API change, ima_pcr_extend() and pcrlock() have been modified.
> > > Since the number of allocated banks is not known in advance, the memory for
> > > the digests must be dynamically allocated. To avoid performance degradation
> > > and to avoid that a PCR extend is not done due to lack of memory, the array
> > > of tpm_digest structures is allocated by the users of the TPM driver at
> > > initialization time.
> > >
> > > Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
> >
> > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
> > Tested-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
>
> I tested that this does not break TPM. I'd need someone to check that
> this does not break IMA. After that, I'm ready to apply this series.

Thanks! I just finished compiling, rebooting, and verifying the IMA
boot-aggregate matches.

While compiling, I saw some messages that "TPM_BUFSIZE is redefined"
for tpm_i2c_infineon, tpm_i2c_nuvoton, and st33zp24. ÂDidn't look to
see if this is a result of this patch set or not.

The IMA boot-aggregate matches the PCRs.

Tested-by: Mimi Zohar <zohar@xxxxxxxxxxxxx> (on x86 for TPM 1.2 & PTT
TPM 2.0)