SYSTEMD.PCRLOCK(5) systemd.pcrlock SYSTEMD.PCRLOCK(5)
NAME
systemd.pcrlock, systemd.pcrlock.d - PCR measurement prediction files
SYNOPSIS
/etc/pcrlock.d/*.pcrlock
/etc/pcrlock.d/*.pcrlock.d/*.pcrlock
/run/pcrlock.d/*.pcrlock
/run/pcrlock.d/*.pcrlock.d/*.pcrlock
/var/lib/pcrlock.d/*.pcrlock
/var/lib/pcrlock.d/*.pcrlock.d/*.pcrlock
/usr/local/pcrlock.d/*.pcrlock
/usr/local/pcrlock.d/*.pcrlock.d/*.pcrlock
/usr/lib/pcrlock.d/*.pcrlock
/usr/lib/pcrlock.d/*.pcrlock.d/*.pcrlock
DESCRIPTION
*.pcrlock files define expected TPM2 PCR measurements of components
involved in the boot process. systemd-pcrlock(8) uses such pcrlock
files to analyze and predict TPM2 PCR measurements. The pcrlock files
are JSON arrays that follow a subset of the TCG Canonical Event Log
Format (CEL-JSON)[1] specification. Specifically the "recnum",
"content", and "content_type" record fields are not used and ignored if
present. Each pcrlock file defines one set of expected, ordered PCR
measurements of a specific component of the boot.
*.pcrlock files may be placed in various .d/ drop-in directories (see
above for a full list). All matching files discovered in these
directories are sorted alphabetically by their file name (without taking
the actual directory they were found in into account): pcrlock files
with alphabetically earlier names are expected to cover measurements
done before those with alphabetically later names. In order to make
positioning pcrlock files in the boot process convenient the files are
expected (by convention, this is not enforced) to be named
"NNN-component.pcrlock" (where NNN is a three-digit decimal number), for
example 750-enter-initrd.pcrlock.
For various components of the boot process more than one alternative
pcrlock file shall be supported (i.e. "variants"). For example to cover
multiple kernels installed in parallel in the access policy, or multiple
versions of the boot loader. This can be done by placing
*.pcrlock.d/*.pcrlock in the drop-in dirs, i.e. a common directory for a
specific component, that contains one or more pcrlock files each
covering one variant of the component. Example:
650-kernel.pcrlock.d/6.5.5-200.fc38.x86_64.pcrlock and
650-kernel.pcrlock.d/6.5.7-100.fc38.x86_64.pcrlock
Use systemd-pcrlock list-components to list all pcrlock files currently
installed.
Use the various lock-* commands of systemd-pcrlock to automatically
generate suitable pcrlock files for various types of resources.
WELL-KNOWN COMPONENTS
Components of the boot process may be defined freely by the
administrator or OS vendor. The following components are well-known
however, and are defined by systemd. The list below is useful for
ordering local pcrlock files properly against these components of the
boot.
240-secureboot-policy.pcrlock
The SecureBoot policy, as recorded to PCR 7. May be generated via
systemd-pcrlock lock-secureboot-policy.
Added in version 255.
250-firmware-code-early.pcrlock
Firmware code measurements, as recorded to PCR 0 and 2, up to the
separator measurement (see 400-secureboot-separator.pcrlock below).
May be generated via systemd-pcrlock lock-firmware-code.
Added in version 255.
250-firmware-config-early.pcrlock
Firmware configuration measurements, as recorded to PCR 1 and 3, up
to the separator measurement (see 400-secureboot-separator.pcrlock
below). May be generated via systemd-pcrlock lock-firmware-config.
Added in version 255.
350-action-efi-application.pcrlock
The EFI "Application" measurement done once by the firmware.
Statically defined.
Added in version 255.
400-secureboot-separator.pcrlock
The EFI "separator" measurement on PCR 7 done once by the firmware
to indicate where firmware control transitions into boot loader/OS
control. Statically defined.
Added in version 255.
500-separator.pcrlock
The EFI "separator" measurements on PCRs 0-6 done once by the
firmware to indicate where firmware control transitions into boot
loader/OS control. Statically defined.
Added in version 255.
550-firmware-code-late.pcrlock
Firmware code measurements, as recorded to PCR 0 and 2, after the
separator measurement (see 400-secureboot-separator.pcrlock above).
May be generated via systemd-pcrlock lock-firmware-code.
Added in version 255.
550-firmware-config-late.pcrlock
Firmware configuration measurements, as recorded to PCR 1 and 3,
after the separator measurement (see
400-secureboot-separator.pcrlock above). May be generated via
systemd-pcrlock lock-firmware-config.
Added in version 255.
600-gpt.pcrlock
The GPT partition table of the booted medium, as recorded to PCR 5
by the firmware. May be generated via systemd-pcrlock lock-gpt.
Added in version 255.
620-secureboot-authority.pcrlock
The SecureBoot authority, as recorded to PCR 7. May be generated via
systemd-pcrlock lock-secureboot-authority.
Added in version 255.
700-action-efi-exit-boot-services.pcrlock
The EFI action generated when ExitBootServices() is generated, i.e.
when the UEFI environment is left and the OS takes over. Covers the
PCR 5 measurement. Statically defined.
Added in version 255.
710-kernel-cmdline.pcrlock
The kernel command line, as measured by the Linux kernel to PCR 9.
May be generated via systemd-pcrlock lock-kernel-cmdline.
Added in version 255.
720-kernel-initrd.pcrlock
The kernel initrd, as measured by the Linux kernel to PCR 9. May be
generated via systemd-pcrlock lock-kernel-initrd.
Added in version 255.
750-enter-initrd.pcrlock
The measurement to PCR 11 systemd-pcrphase-initrd.service(8) makes
when the initrd initializes. Statically defined.
Added in version 255.
800-leave-initrd.pcrlock
The measurement to PCR 11 systemd-pcrphase-initrd.service(8) makes
when the initrd finishes. Statically defined.
Added in version 255.
820-machine-id.pcrlock
The measurement to PCR 15 systemd-pcrmachine.service(8) makes at
boot, covering /etc/machine-id contents. May be generated via
systemd-pcrlock lock-machine-id.
Added in version 255.
830-root-file-system.pcrlock
The measurement to PCR 15 systemd-pcrfs-root.service(8) makes at
boot, covering the root file system identity. May be generated via
systemd-pcrlock lock-file-system.
Added in version 255.
850-sysinit.pcrlock
The measurement to PCR 11 systemd-pcrphase-sysinit.service(8) makes
when the main userspace did basic initialization and will now
proceed to start regular system services. Statically defined.
Added in version 255.
900-ready.pcrlock
The measurement to PCR 11 systemd-pcrphase.service(8) makes when the
system fully booted up. Statically defined.
Added in version 255.
950-shutdown.pcrlock
The measurement to PCR 11 systemd-pcrphase.service(8) makes when the
system begins shutdown. Statically defined.
Added in version 255.
990-final.pcrlock
The measurement to PCR 11 systemd-pcrphase-sysinit.service(8) makes
when the system is close to finishing shutdown. Statically defined.
Added in version 255.
SEE ALSO
systemd(1), systemd-pcrlock(8)
NOTES
1. TCG Canonical Event Log Format (CEL-JSON)
https://trustedcomputinggroup.org/resource/canonical-event-log-format/
systemd 257.9 SYSTEMD.PCRLOCK(5)
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