Re: PCR9 missmatches since latest updates

No HTML allowed - fair. Resending Plaintext.=0A=
________________________________________=0A=
From:=A0Matthias R. Wiora <[email protected]>=0A=
Sent:=A030 December 2025 05:30 AM=0A=
To:=A0Milan Broz <[email protected]>; [email protected] <cryptse=
[email protected]>=0A=
Cc:[email protected] <[email protected].=
org>=0A=
Subject:=A0Re: PCR9 missmatches since latest updates=0A=
=A0=0A=
In case someone steps on this - just a short note:=0A=
I resolved this by having a reference to the PCRs measured in tpm2_evenlog =
available under "/sys/kernel/security/tpm0/binary_bios_measurements".=0A=
=0A=
Based on that I was able to satisfy my requirement to know how the PCRs loo=
k like at the moment I want to know, if my device state is trustworth BEFOR=
E entering my passphrase.=0A=
=0A=
Note: I figured out that some devices (in this case with a discrete TPM) se=
em to hold in this binary_bios_measurement only SHA1, while the TPM2 device=
 is capable of SHA1 and SHA256 banks.=0A=
=0A=
I wonder how this will be handled for tpm2-protected disks, that are also e=
ncrypted at the moment the system has been completely booted up. This case =
should be affected by the exact same challenge.=0A=
=0A=
Cheers,=0A=
// Matthias=0A=
=0A=
CC to systemd-devel=0A=
=0A=
________________________________________=0A=
From:=A0Matthias R. Wiora <[email protected]>=0A=
Sent:=A022 December 2025 05:05 PM=0A=
To:=A0Milan Broz <[email protected]>; [email protected] <cryptse=
[email protected]>=0A=
Subject:=A0Re: PCR9 missmatches since latest updates=0A=
=A0=0A=
Yeah! Your hint was perfect! Thanks!=0A=
=0A=
Obviously Systemd Release 259 caused the change:=0A=
https://github.com/systemd/systemd/releases/tag/v259=0A=
=0A=
Extract:=0A=
```=0A=
Information about the=A0initialization of NvPCRs is measured into PCR 9, an=
d finalized by a=0A=
=A0=A0=A0 separator measurement.=0A=
```=0A=
=0A=
as this seems to be by intention with a good reason, I will investigate thi=
s further and most probably adapt my tpm2-kira implementation to fullfil th=
e expectations of PCR 9 at the moment before unlock :)=0A=
=0A=
Cheers,=0A=
Matthias=0A=
=0A=
________________________________________=0A=
From:=A0Milan Broz <[email protected]>=0A=
Sent:=A022 December 2025 04:17 PM=0A=
To:=A0Matthias R. Wiora <[email protected]>; [email protected] =
<[email protected]>=0A=
Subject:=A0Re: PCR9 missmatches since latest updates=0A=
=A0=0A=
On 12/22/25 3:32 PM, Matthias R. Wiora wrote:=0A=
> Hi all,=0A=
>=0A=
> with linux kernel 6.18.2-arch2-1 and cryptsetup-2.8.3-1 (running arch) I =
am experiencing issues when resealing my TPM2 protected enclave protected b=
y measurements on PCR9 on my machine (verified on another device with a sim=
ilar setup).=0A=
> This behaviour changed recently and I could not find any release notes in=
formation, so I decided to start here with my investigations.=0A=
=0A=
I think you need to cc systemd list, or maybe better report issue to system=
d, as it is systemd cryptsetup tools handling TPM2 PCRs.=0A=
=0A=
Milan=