Re: [PATCH =v2 3/3] tpm: selftest: cleanup after unseal with wrong auth/policy test

From: Tadeusz Struk
Date: Thu Dec 12 2019 - 15:49:00 EST

On 12/12/19 11:51 AM, James Bottomley wrote:
> TPM2_Clear reprovisions the SPS ... that would make all currently
> exported TPM keys go invalid. I know these tests should be connected
> to a vTPM, so doing this should be safe, but if this accidentally got
> executed on your laptop all TPM relying functions would be disrupted,
> which doesn't seem to be the best thing to hard wire into a test.

That is true, but it will need to be executed as root, and root
should know what she/he is doing ;)

> What about doing a TPM2_DictionaryAttackLockReset instead, which is the
> least invasive route to fixing the problem ... provided you know what
> the lockout authorization is.

I can change tpm2_clear to tpm2_dictionarylockout -c if we want to make
it foolproof. In this case we can assume that the lockout auth is empty.