Trusted Boot in Fedora

[Miloslav Trmač]

On Mon, Jun 27, 2011 at 5:14 PM, Simo Sorce <simo at redhat.com> wrote:
> On Mon, 2011-06-27 at 16:53 +0200, Miloslav Trmač wrote:
>> On Mon, Jun 27, 2011 at 4:08 PM, Simo Sorce <simo at redhat.com> wrote:
>> The hardware manufacturer _only_ signs the sinit blob.  Any kernel/OS
>> you use can be measured/"protected" by the TPM without any further
>> involvement of the manufacturer.
>
> How does the sinit blob verify the kernel ?

It doesn't, really.  My understanding is that it takes a hash of the
contents of memory (and perhaps other state, I don't know) and submits
this "measurement" to the TPM.  The sinit blob doesn't contain any
policy or configuration: it is only a mechanism for reducing the
complete "system state" into a hash value.

The hardware owner configures the TPM so that submitting specific
"measurements" is required to use keys stored in the TPM.  What those
keys do is not specified by the TPM: for example, they may be used to
allow access to an encrypted hard drive, or to sign the "remote
attestation" data.

> Can you add some documentation about that in the feature page request as
> others have asked please ?
I'm afraid I'm not the feature owner, only a semi-informed outsider.
I'd love to see the feature page updated/expanded as well.
   Mirek