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diff --git a/man/systemd-pcrphase.service.xml b/man/systemd-pcrphase.service.xml new file mode 100644 index 0000000..2d711e4 --- /dev/null +++ b/man/systemd-pcrphase.service.xml @@ -0,0 +1,245 @@ +<?xml version='1.0'?> <!--*-nxml-*--> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> +<!-- SPDX-License-Identifier: LGPL-2.1-or-later --> + +<refentry id="systemd-pcrphase.service" conditional='ENABLE_BOOTLOADER' + xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>systemd-pcrphase.service</title> + <productname>systemd</productname> + </refentryinfo> + + <refmeta> + <refentrytitle>systemd-pcrphase.service</refentrytitle> + <manvolnum>8</manvolnum> + </refmeta> + + <refnamediv> + <refname>systemd-pcrphase.service</refname> + <refname>systemd-pcrphase-sysinit.service</refname> + <refname>systemd-pcrphase-initrd.service</refname> + <refname>systemd-pcrmachine.service</refname> + <refname>systemd-pcrfs-root.service</refname> + <refname>systemd-pcrfs@.service</refname> + <refname>systemd-pcrextend</refname> + <refpurpose>Measure boot phase into TPM2 PCR 11, machine ID and file system identity into PCR 15</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <para><filename>systemd-pcrphase.service</filename></para> + <para><filename>systemd-pcrphase-sysinit.service</filename></para> + <para><filename>systemd-pcrphase-initrd.service</filename></para> + <para><filename>systemd-pcrmachine.service</filename></para> + <para><filename>systemd-pcrfs-root.service</filename></para> + <para><filename>systemd-pcrfs@.service</filename></para> + <para><filename>/usr/lib/systemd/systemd-pcrextend</filename> <optional><replaceable>STRING</replaceable></optional></para> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><filename>systemd-pcrphase.service</filename>, + <filename>systemd-pcrphase-sysinit.service</filename>, and + <filename>systemd-pcrphase-initrd.service</filename> are system services that measure specific strings + into TPM2 PCR 11 during boot at various milestones of the boot process.</para> + + <para><filename>systemd-pcrmachine.service</filename> is a system service that measures the machine ID + (see <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>) into + PCR 15.</para> + + <para><filename>systemd-pcrfs-root.service</filename> and <filename>systemd-pcrfs@.service</filename> are + services that measure file system identity information (i.e. mount point, file system type, label and + UUID, partition label and UUID) into PCR 15. <filename>systemd-pcrfs-root.service</filename> does so for + the root file system, <filename>systemd-pcrfs@.service</filename> is a template unit that measures the + file system indicated by its instance identifier instead.</para> + + <para>These services require + <citerefentry><refentrytitle>systemd-stub</refentrytitle><manvolnum>7</manvolnum></citerefentry> to be + used in a unified kernel image (UKI). They execute no operation when the stub has not been used to invoke + the kernel. The stub will measure the invoked kernel and associated vendor resources into PCR 11 before + handing control to it; once userspace is invoked these services then will extend TPM2 PCR 11 with certain + literal strings indicating phases of the boot process. During a regular boot process PCR 11 is extended + with the following strings:</para> + + <orderedlist> + <listitem><para><literal>enter-initrd</literal> — early when the initrd initializes, before activating + system extension images for the initrd. It acts as a barrier between the time where the kernel + initializes and where the initrd starts operating and enables system extension images, i.e. code + shipped outside of the UKI. (This extension happens when the + <citerefentry><refentrytitle>systemd-pcrphase-initrd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + service is started.)</para></listitem> + + <listitem><para><literal>leave-initrd</literal> — when the initrd is about to transition into the host + file system. It acts as barrier between initrd code and host OS code. (This extension happens when the + <filename>systemd-pcrphase-initrd.service</filename> service is stopped.)</para></listitem> + + <listitem><para><literal>sysinit</literal> — when basic system initialization is complete (which + includes local file systems having been mounted), and the system begins starting regular system + services. (This extension happens when the + <citerefentry><refentrytitle>systemd-pcrphase-sysinit.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + service is started.)</para></listitem> + + <listitem><para><literal>ready</literal> — during later boot-up, after remote file systems have been + activated (i.e. after <filename>remote-fs.target</filename>), but before users are permitted to log in + (i.e. before <filename>systemd-user-sessions.service</filename>). It acts as barrier between the time + where unprivileged regular users are still prohibited to log in and where they are allowed to log in. + (This extension happens when the <filename>systemd-pcrphase.service</filename> service is started.) + </para></listitem> + + <listitem><para><literal>shutdown</literal> — when the system shutdown begins. It acts as barrier + between the time the system is fully up and running and where it is about to shut down. (This extension + happens when the <filename>systemd-pcrphase.service</filename> service is stopped.)</para></listitem> + + <listitem><para><literal>final</literal> — at the end of system shutdown. It acts as barrier between + the time the service manager still runs and when it transitions into the final shutdown phase where + service management is not available anymore. (This extension happens when the + <citerefentry><refentrytitle>systemd-pcrphase-sysinit.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + service is stopped.)</para></listitem> + </orderedlist> + + <para>During a regular system lifecycle, PCR 11 is extended with the strings + <literal>enter-initrd</literal>, <literal>leave-initrd</literal>, <literal>sysinit</literal>, + <literal>ready</literal>, <literal>shutdown</literal>, and <literal>final</literal>.</para> + + <para>Specific phases of the boot process may be referenced via the series of strings measured, separated + by colons (the "phase path"). For example, the phase path for the regular system runtime is + <literal>enter-initrd:leave-initrd:sysinit:ready</literal>, while the one for the initrd is just + <literal>enter-initrd</literal>. The phase path for the boot phase before the initrd is an empty string; + because that's hard to pass around a single colon (<literal>:</literal>) may be used instead. Note that + the aforementioned six strings are just the default strings and individual systems might measure other + strings at other times, and thus implement different and more fine-grained boot phases to bind policy + to.</para> + + <para>By binding policy of TPM2 objects to a specific phase path it is possible to restrict access to + them to specific phases of the boot process, for example making it impossible to access the root file + system's encryption key after the system transitioned from the initrd into the host root file system. + </para> + + <para>Use + <citerefentry><refentrytitle>systemd-measure</refentrytitle><manvolnum>1</manvolnum></citerefentry> to + pre-calculate expected PCR 11 values for specific boot phases (via the <option>--phase=</option> switch). + </para> + + <para><filename>systemd-pcrfs-root.service</filename> and <filename>systemd-pcrfs@.service</filename> are + automatically pulled into the initial transaction by + <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry> + for the root and <filename>/var/</filename> file + systems. <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry> + will do this for all mounts with the <option>x-systemd.pcrfs</option> mount option in + <filename>/etc/fstab</filename>.</para> + </refsect1> + + <refsect1> + <title>Options</title> + + <para>The <filename>/usr/lib/systemd/system-pcrextend</filename> executable may also be invoked from the + command line, where it expects the word to extend into PCR 11, as well as the following switches:</para> + + <variablelist> + <varlistentry> + <term><option>--bank=</option></term> + + <listitem><para>Takes the PCR banks to extend the specified word into. If not specified the tool + automatically determines all enabled PCR banks and measures the word into all of + them.</para> + + <xi:include href="version-info.xml" xpointer="v252"/></listitem> + </varlistentry> + + <varlistentry> + <term><option>--pcr=</option></term> + + <listitem><para>Takes the index of the PCR to extend. If <option>--machine-id</option> or + <option>--file-system=</option> are specified defaults to 15, otherwise defaults to 11.</para> + + <xi:include href="version-info.xml" xpointer="v255"/></listitem> + </varlistentry> + + <varlistentry> + <term><option>--tpm2-device=</option><replaceable>PATH</replaceable></term> + + <listitem><para>Controls which TPM2 device to use. Expects a device node path referring to the TPM2 + chip (e.g. <filename>/dev/tpmrm0</filename>). Alternatively the special value <literal>auto</literal> + may be specified, in order to automatically determine the device node of a suitable TPM2 device (of + which there must be exactly one). The special value <literal>list</literal> may be used to enumerate + all suitable TPM2 devices currently discovered.</para> + + <xi:include href="version-info.xml" xpointer="v252"/></listitem> + </varlistentry> + + <varlistentry> + <term><option>--graceful</option></term> + + <listitem><para>If no TPM2 firmware, kernel subsystem, kernel driver or device support is found, exit + with exit status 0 (i.e. indicate success). If this is not specified any attempt to measure without a + TPM2 device will cause the invocation to fail.</para> + + <xi:include href="version-info.xml" xpointer="v253"/></listitem> + </varlistentry> + + <varlistentry> + <term><option>--machine-id</option></term> + + <listitem><para>Instead of measuring a word specified on the command line into PCR 11, measure the + host's machine ID into PCR 15.</para> + + <xi:include href="version-info.xml" xpointer="v253"/></listitem> + </varlistentry> + + <varlistentry> + <term><option>--file-system=</option></term> + + <listitem><para>Instead of measuring a word specified on the command line into PCR 11, measure + identity information of the specified file system into PCR 15. The parameter must be the path to the + established mount point of the file system to measure.</para> + + <xi:include href="version-info.xml" xpointer="v253"/></listitem> + </varlistentry> + + <xi:include href="standard-options.xml" xpointer="help" /> + <xi:include href="standard-options.xml" xpointer="version" /> + + </variablelist> + </refsect1> + + <refsect1> + <title>Files</title> + + <variablelist> + <varlistentry> + <term><filename>/run/log/systemd/tpm2-measure.log</filename></term> + + <listitem><para>Measurements are logged into an event log file maintained in + <filename>/run/log/systemd/tpm2-measure.log</filename>, which contains a <ulink + url="https://www.rfc-editor.org/rfc/rfc7464.html">JSON-SEQ</ulink> series of objects that follow the + general structure of the <ulink + url="https://trustedcomputinggroup.org/resource/canonical-event-log-format/">TCG Common Event Log + Format (CEL-JSON)</ulink> event objects (but lack the <literal>recnum</literal> + field).</para> + + <para>A <constant>LOCK_EX</constant> BSD file lock (<citerefentry + project='man-pages'><refentrytitle>flock</refentrytitle><manvolnum>2</manvolnum></citerefentry>) on + the log file is acquired while the measurement is made and the file is updated. Thus, applications + that intend to acquire a consistent quote from the TPM with the associated snapshot of the event log + should acquire a <constant>LOCK_SH</constant> lock while doing so.</para> + + <xi:include href="version-info.xml" xpointer="v252"/></listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-stub</refentrytitle><manvolnum>7</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-measure</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <ulink url="https://systemd.io/TPM2_PCR_MEASUREMENTS">TPM2 PCR Measurements Made by systemd</ulink> + </para> + </refsect1> + +</refentry> |