trust anchor fingerprint about architecture HOT 7 CLOSED

Relates to issue #32

from architecture.

Updated architecture doc section for the definition of "Trust Anchor" to reflect the following.

• Trust Anchor fingerprint can be stored as part of Trust Anchor for unique identification
• It should be checked and used in Trust Anchor management to uniquely identify the right one.

See draft update on this.

Note a reference that RFC6024 talks about "Trust Anchor Management". It defines a Trust Anchor Format about what it should contain.

from architecture.

Addressed with pull request #40 - #40

from architecture.

Quoted the updated definition of Trust Anchor here.

"Trust Anchor: A public key in a device whose corresponding private
key is held by an entity implicitly trusted by the device. The
Trust Anchor may be a certificate or it may be a raw public key
along with additional data if necessary such as its public key
algorithm and parameters.
The Trust Anchor is normally stored in a location that resists
unauthorized modification, insertion, or replacement. The digital
fingerprint of a Trust Anchor may be stored along with the Trust
Anchor certificate or public key. The Trust Anchor fingerprint
can be part of Trust Anchor format. A device can use the
fingerprint to uniquely identify a Trust Anchor.
The Trust Anchor private key owner can sign certificates of other
public keys, which conveys trust about those keys to the device.
A certificate signed by the Trust Anchor communicates that the
private key holder of the signed certificate is trusted by the
Trust Anchor holder, and can therefore be trusted by the device.
Trust Anchors in a device may be updated by an authorized party
when a Trust Anchor should be deprecated or a new Trust Anchor
should be added."

from architecture.

All good except one sentence is confusing:
"The Trust Anchor fingerprint can be part of Trust Anchor format."
What is "Trust Anchor format"?

from architecture.

If it is a fingerprint, shall we define what fingerprint it should be and how it is represented (SHA1 or SHA2 hash of a certificate or some more)? When it is a public key, what structure should a TEE support? A Trust Anchor can consist of a public key and fingerprint (of the certificate). I was thinking of a structure we may cite from others. RFC6024 describes requirement for a Trust Anchor Format. Maybe we loosely leave the trust anchor content structure to TEE about how it will interpret a "fingerprint", a "public key", and their combined use?

By this, I will just remove that line "The Trust Anchor fingerprint can be part of Trust Anchor format.". The prior sentence has described it will be stored along with other data. The interpretation and content of a fingerprint, e.g. fingerprint algorithm, will be left to TEE.

from architecture.

Verified fixed in draft -02 and later

from architecture.