| 1. | TCG Canonical Event Log Format (CEL-JSON) |
NAME
systemd.pcrlock, systemd.pcrlock.d - PCR measurement prediction files
SYNOPSIS
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
Added in version 255.
250-firmware-code-early.pcrlock
Added in version 255.
250-firmware-config-early.pcrlock
Added in version 255.
350-action-efi-application.pcrlock
Added in version 255.
400-secureboot-separator.pcrlock
Added in version 255.
500-separator.pcrlock
Added in version 255.
550-firmware-code-late.pcrlock
Added in version 255.
550-firmware-config-late.pcrlock
Added in version 255.
600-gpt.pcrlock
Added in version 255.
620-secureboot-authority.pcrlock
Added in version 255.
700-action-efi-exit-boot-services.pcrlock
Added in version 255.
710-kernel-cmdline.pcrlock
Added in version 255.
720-kernel-initrd.pcrlock
Added in version 255.
750-enter-initrd.pcrlock
Added in version 255.
800-leave-initrd.pcrlock
Added in version 255.
820-machine-id.pcrlock
Added in version 255.
830-root-file-system.pcrlock
Added in version 255.
850-sysinit.pcrlock
Added in version 255.
900-ready.pcrlock
Added in version 255.
950-shutdown.pcrlock
Added in version 255.
990-final.pcrlock
Added in version 255.
SEE ALSO
systemd(1), systemd-pcrlock(8)
NOTES
- 1.
TCG Canonical Event Log Format (CEL-JSON)