docs: Extend trusted keys documentation for TPM 2.0

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@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This commit is contained in:
Stefan Berger 2018-10-19 06:17:58 -04:00 committed by Mimi Zohar
parent d958083a8f
commit 4264f27a08
1 changed files with 30 additions and 1 deletions

View File

@ -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
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