Re: [PATCH] docs: Extend trusted keys documentation for TPM 2.0

[Jerry Snitselaar]

On Mon Nov 05 18, Jerry Snitselaar wrote:
> On Fri Oct 19 18, Stefan Berger wrote:
> > Extend the documentation for trusted keys with documentation for how to
> > set up a key for a TPM 2.0 so it can be used with a TPM 2.0 as well.
> >
> > Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
> > Reviewed-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
> > ---
> > .../security/keys/trusted-encrypted.rst       | 31 ++++++++++++++++++-
> > 1 file changed, 30 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/security/keys/trusted-encrypted.rst b/Documentation/security/keys/trusted-encrypted.rst
> > index 3bb24e09a332..6ec6bb2ac497 100644
> > --- a/Documentation/security/keys/trusted-encrypted.rst
> > +++ b/Documentation/security/keys/trusted-encrypted.rst
> > @@ -18,10 +18,33 @@ integrity verifications match.  A loaded Trusted Key can be updated with new
> > when the kernel and initramfs are updated.  The same key can have many saved
> > blobs under different PCR values, so multiple boots are easily supported.
> >
> > +TPM 1.2
> > +-------
> > +
> > By default, trusted keys are sealed under the SRK, which has the default
> > authorization value (20 zeros).  This can be set at takeownership time with the
> > trouser's utility: "tpm_takeownership -u -z".
> >
> > +TPM 2.0
> > +-------
> > +
> > +The user must first create a storage key and make it persistent, so the key is
> > +available after reboot. This can be done using the following commands.
> > +
> > +With the IBM TSS 2 stack::
> > +
> > +  #> tsscreateprimary -hi o -st
> > +  Handle 80000000
> > +  #> tssevictcontrol -hi o -ho 80000000 -hp 81000001
> > +
> > +Or with the Intel TSS 2 stack::
> > +
> > +  #> tpm2_createprimary --hierarchy o -G rsa2048 -o key.ctxt
> > +  [...]
> > +  handle: 0x800000FF
> > +  #> tpm2_evictcontrol -c key.ctxt -p 0x81000001
> > +  persistentHandle: 0x81000001
> > +
>
> Is that the correct option for tpm2_evictcontrol? What I'm seeing
> in the versions I have is -S or -persistent= for specifying the persistent handle.
>
> Other than that looks good to me.

William, is the above correct?

> > Usage::
> >
> >    keyctl add trusted name "new keylen [options]" ring
> > @@ -30,7 +53,9 @@ Usage::
> >    keyctl print keyid
> >
> >    options:
> > -       keyhandle=    ascii hex value of sealing key default 0x40000000 (SRK)
> > +       keyhandle=    ascii hex value of sealing key
> > +                       TPM 1.2: default 0x40000000 (SRK)
> > +                       TPM 2.0: no default; must be passed every time
> >       keyauth=	     ascii hex auth for sealing key default 0x00...i
> >                     (40 ascii zeros)
> >       blobauth=     ascii hex auth for sealed data default 0x00...
> > @@ -84,6 +109,10 @@ Examples of trusted and encrypted key usage:
> >
> > Create and save a trusted key named "kmk" of length 32 bytes::
> >
> > +Note: When using a TPM 2.0 with a persistent key with handle 0x81000001,
> > +append 'keyhandle=0x81000001' to statements between quotes, such as
> > +"new 32 keyhandle=0x81000001".
> > +
> >    $ keyctl add trusted kmk "new 32" @u
> >    440502848
> >
> > --
> > 2.17.2