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+<?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-cryptsetup-generator" conditional='HAVE_LIBCRYPTSETUP'>
+
+ <refentryinfo>
+ <title>systemd-cryptsetup-generator</title>
+ <productname>systemd</productname>
+ </refentryinfo>
+
+ <refmeta>
+ <refentrytitle>systemd-cryptsetup-generator</refentrytitle>
+ <manvolnum>8</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>systemd-cryptsetup-generator</refname>
+ <refpurpose>Unit generator for <filename>/etc/crypttab</filename></refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <para><filename>/usr/lib/systemd/system-generators/systemd-cryptsetup-generator</filename></para>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para><filename>systemd-cryptsetup-generator</filename> is a
+ generator that translates <filename>/etc/crypttab</filename> into
+ native systemd units early at boot and when configuration of the
+ system manager is reloaded. This will create
+ <citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ units as necessary.</para>
+
+ <para><filename>systemd-cryptsetup-generator</filename> implements
+ <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Kernel Command Line</title>
+
+ <para><filename>systemd-cryptsetup-generator</filename>
+ understands the following kernel command line parameters:</para>
+
+ <variablelist class='kernel-commandline-options'>
+ <varlistentry>
+ <term><varname>luks=</varname></term>
+ <term><varname>rd.luks=</varname></term>
+
+ <listitem><para>Takes a boolean argument. Defaults to <literal>yes</literal>. If
+ <literal>no</literal>, disables the generator entirely. <varname>rd.luks=</varname> is honored only
+ in the initrd while <varname>luks=</varname> is honored by both the main system and in the initrd.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>luks.crypttab=</varname></term>
+ <term><varname>rd.luks.crypttab=</varname></term>
+
+ <listitem><para>Takes a boolean argument. Defaults to <literal>yes</literal>. If
+ <literal>no</literal>, causes the generator to ignore any devices configured in
+ <filename>/etc/crypttab</filename> (<varname>luks.uuid=</varname> will still work however).
+ <varname>rd.luks.crypttab=</varname> is honored only in initrd while
+ <varname>luks.crypttab=</varname> is honored by both the main system and the initrd.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>luks.uuid=</varname></term>
+ <term><varname>rd.luks.uuid=</varname></term>
+
+ <listitem><para>Takes a LUKS superblock UUID as argument. This will activate the specified device as
+ part of the boot process as if it was listed in <filename>/etc/crypttab</filename>. This option may
+ be specified more than once in order to set up multiple devices. <varname>rd.luks.uuid=</varname> is
+ honored only in the initrd, while <varname>luks.uuid=</varname> is honored by both the main system
+ and the initrd.</para>
+
+ <para>If <filename>/etc/crypttab</filename> contains entries with the same UUID, then the name,
+ keyfile and options specified there will be used. Otherwise, the device will have the name
+ <literal>luks-UUID</literal>.</para>
+
+ <para>If <filename>/etc/crypttab</filename> exists, only those UUIDs specified on the kernel command
+ line will be activated in the initrd or the real root.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>luks.name=</varname></term>
+ <term><varname>rd.luks.name=</varname></term>
+
+ <listitem><para>Takes a LUKS super block UUID followed by an
+ <literal>=</literal> and a name. This implies
+ <varname>rd.luks.uuid=</varname> or
+ <varname>luks.uuid=</varname> and will additionally make the
+ LUKS device given by the UUID appear under the provided
+ name.</para>
+
+ <para>This parameter is the analogue of the first <citerefentry><refentrytitle>crypttab</refentrytitle>
+ <manvolnum>5</manvolnum></citerefentry> field <replaceable>volume-name</replaceable>.</para>
+
+ <para><varname>rd.luks.name=</varname> is honored only in the initrd, while
+ <varname>luks.name=</varname> is honored by both the main system and the initrd.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>luks.data=</varname></term>
+ <term><varname>rd.luks.data=</varname></term>
+
+ <listitem><para>Takes a LUKS super block UUID followed by a <literal>=</literal> and a block device
+ specification for device hosting encrypted data.</para>
+
+ <para>For those entries specified with <varname>rd.luks.uuid=</varname> or
+ <varname>luks.uuid=</varname>, the data device will be set to the one specified by
+ <varname>rd.luks.data=</varname> or <varname>luks.data=</varname> of the corresponding UUID.</para>
+
+ <para>LUKS data device parameter is useful for specifying encrypted data devices with detached headers specified in
+ <varname>luks.options</varname> entry containing <literal>header=</literal> argument. For example,
+ <varname>rd.luks.uuid=</varname>b40f1abf-2a53-400a-889a-2eccc27eaa40
+ <varname>rd.luks.options=</varname>b40f1abf-2a53-400a-889a-2eccc27eaa40=header=/path/to/luks.hdr
+ <varname>rd.luks.data=</varname>b40f1abf-2a53-400a-889a-2eccc27eaa40=/dev/sdx.
+ Hence, in this case, we will attempt to unlock LUKS device assembled from data device <literal>/dev/sdx</literal>
+ and LUKS header (metadata) put in <literal>/path/to/luks.hdr</literal> file. This syntax is for now
+ only supported on a per-device basis, i.e. you have to specify LUKS device UUID.</para>
+
+ <para>This parameter is the analogue of the second <citerefentry><refentrytitle>crypttab</refentrytitle>
+ <manvolnum>5</manvolnum></citerefentry> field <replaceable>encrypted-device</replaceable>.</para>
+
+ <para><varname>rd.luks.data=</varname> is honored only in the initrd, while
+ <varname>luks.data=</varname> is honored by both the main system and in the initrd.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>luks.key=</varname></term>
+ <term><varname>rd.luks.key=</varname></term>
+
+ <listitem><para>Takes a password file name as argument or a
+ LUKS super block UUID followed by a <literal>=</literal> and a
+ password file name.</para>
+
+ <para>For those entries specified with
+ <varname>rd.luks.uuid=</varname> or
+ <varname>luks.uuid=</varname>, the password file will be set
+ to the one specified by <varname>rd.luks.key=</varname> or
+ <varname>luks.key=</varname> of the corresponding UUID, or the
+ password file that was specified without a UUID.</para>
+
+ <para>It is also possible to specify an external device which
+ should be mounted before we attempt to unlock the LUKS device.
+ systemd-cryptsetup will use password file stored on that
+ device. Device containing password file is specified by
+ appending colon and a device identifier to the password file
+ path. For example,
+ <varname>rd.luks.uuid=</varname>b40f1abf-2a53-400a-889a-2eccc27eaa40
+ <varname>rd.luks.key=</varname>b40f1abf-2a53-400a-889a-2eccc27eaa40=/keyfile:LABEL=keydev.
+ Hence, in this case, we will attempt to mount file system
+ residing on the block device with label <literal>keydev</literal>.
+ This syntax is for now only supported on a per-device basis,
+ i.e. you have to specify LUKS device UUID.</para>
+
+ <para>This parameter is the analogue of the third <citerefentry><refentrytitle>crypttab</refentrytitle>
+ <manvolnum>5</manvolnum></citerefentry> field <replaceable>key-file</replaceable>.</para>
+
+ <para><varname>rd.luks.key=</varname> is honored only in the initrd, while
+ <varname>luks.key=</varname> is honored by both the main system and in the initrd.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>luks.options=</varname></term>
+ <term><varname>rd.luks.options=</varname></term>
+
+ <listitem><para>Takes a LUKS super block UUID followed by an
+ <literal>=</literal> and a string of options separated by
+ commas as argument. This will override the options for the
+ given UUID.</para>
+ <para>If only a list of options, without an UUID, is
+ specified, they apply to any UUIDs not specified elsewhere,
+ and without an entry in
+ <filename>/etc/crypttab</filename>.</para>
+
+ <para>This parameter is the analogue of the fourth <citerefentry><refentrytitle>crypttab</refentrytitle>
+ <manvolnum>5</manvolnum></citerefentry> field <replaceable>options</replaceable>.</para>
+
+ <para>It is possible to specify an external device which
+ should be mounted before we attempt to unlock the LUKS device.
+ systemd-cryptsetup will assemble LUKS device by combining
+ data device specified in <varname>luks.data</varname> with
+ detached LUKS header found in <literal>header=</literal>
+ argument. For example,
+ <varname>rd.luks.uuid=</varname>b40f1abf-2a53-400a-889a-2eccc27eaa40
+ <varname>rd.luks.options=</varname>b40f1abf-2a53-400a-889a-2eccc27eaa40=header=/luks.hdr:LABEL=hdrdev
+ <varname>rd.luks.data=</varname>b40f1abf-2a53-400a-889a-2eccc27eaa40=/dev/sdx.
+ Hence, in this case, we will attempt to mount file system
+ residing on the block device with label <literal>hdrdev</literal>, and look
+ for <literal>luks.hdr</literal> on that file system. Said header will be used
+ to unlock (decrypt) encrypted data stored on /dev/sdx.
+ This syntax is for now only supported on a per-device basis,
+ i.e. you have to specify LUKS device UUID.</para>
+
+ <para><varname>rd.luks.options=</varname> is honored only by initial
+ RAM disk (initrd) while <varname>luks.options=</varname> is
+ honored by both the main system and the initrd.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+ <para>
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd-cryptenroll</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ </para>
+ </refsect1>
+
+</refentry>