Re: [PATCH v8 00/22] add integrity and security to TPM2 transactions

Jarkko Sakkinen
2024-04-30T18:37:24Z

On Tue Apr 30, 2024 at 2:18 PM EEST, Stefan Berger wrote:
>
>
> On 4/29/24 19:49, Jarkko Sakkinen wrote:
> > On Tue Apr 30, 2024 at 1:26 AM EEST, Jarkko Sakkinen wrote:
> >> Right and obviously 3rd option is to send a PR to
> >> https://gitlab.com/jarkkojs/linux-tpmdd-test.
> >>
> >> I.e. patch file goes to patches/qemu (BR2_GLOBAL_PATCH_DIR
> >> points there).
> >
> > Stefan, can I do a "zero QEMU changes" negative test for
> > changing null seed by somehow reseting swtpm? That would
> > be best possible option (if it is possible).
>
> You cannot easily reset swtpm without changing 'something' and resetting
> the NULL seed only works when running TPM2_Startup. You could modify
> some TPM2 command to do what HierarchyStartup does with the nullSeed to
> simulate what you want.

Hmm... I'm not too eager to modify swtpm itself.

So one hacky option might be to run swtpm using system() in an
interposer program and that program would again create chardev
using cuse.

That program would again have to modify traffic "at some point".

Maybe +1 command after TPM2_StartAuthSession or later?

BR, Jarkko