man: Add xinclude namespace

[thirdparty/systemd.git] / man / systemd-homed.service.xml

diff --git a/man/systemd-homed.service.xml b/man/systemd-homed.service.xml
index e4c520ff2fabab914e1e5c4022f72f4ca7b70fc0..9564cec6f5148a497a96e55bc29ff049f7824cdd 100644 (file)
--- a/man/systemd-homed.service.xml
+++ b/man/systemd-homed.service.xml
@@ -1,9 +1,10 @@
 <?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+ -->
+<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
 
-<refentry id="systemd-homed.service" conditional='ENABLE_HOMED'>
+<refentry id="systemd-homed.service" conditional='ENABLE_HOMED'
+          xmlns:xi="http://www.w3.org/2001/XInclude">
 
   <refentryinfo>
     <title>systemd-homed.service</title>
@@ -47,13 +48,64 @@
     <citerefentry><refentrytitle>userdbctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
   </refsect1>
 
+  <refsect1>
+    <title>Key Management</title>
+
+    <para>User records are cryptographically signed with a public/private key pair (the signature is part of
+    the JSON record itself). For a user to be permitted to log in locally the public key matching the
+    signature of their user record must be installed. For a user record to be modified locally the private
+    key matching the signature must be installed locally, too. The keys are stored in the
+    <filename>/var/lib/systemd/home/</filename> directory:</para>
+
+    <variablelist>
+
+      <varlistentry>
+        <term><filename>/var/lib/systemd/home/local.private</filename></term>
+
+        <listitem><para>The private key of the public/private key pair used for local records. Currently,
+        only a single such key may be installed.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><filename>/var/lib/systemd/home/local.public</filename></term>
+
+        <listitem><para>The public key of the public/private key pair used for local records. Currently,
+        only a single such key may be installed.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><filename>/var/lib/systemd/home/*.public</filename></term>
+
+        <listitem><para>Additional public keys. Any users whose user records are signed with any of these keys
+        are permitted to log in locally. An arbitrary number of keys may be installed this
+        way.</para></listitem>
+      </varlistentry>
+    </variablelist>
+
+    <para>All key files listed above are in PEM format.</para>
+
+    <para>In order to migrate a home directory from a host <literal>foobar</literal> to another host
+    <literal>quux</literal> it is hence sufficient to copy
+    <filename>/var/lib/systemd/home/local.public</filename> from the host <literal>foobar</literal> to
+    <literal>quux</literal>, maybe calling the file on the destination <filename
+    index="false">/var/lib/systemd/home/foobar.public</filename>, reflecting the origin of the key. If the
+    user record should be modifiable on <literal>quux</literal> the pair
+    <filename>/var/lib/systemd/home/local.public</filename> and
+    <filename>/var/lib/systemd/home/local.private</filename> need to be copied from <literal>foobar</literal>
+    to <literal>quux</literal>, and placed under the identical paths there, as currently only a single
+    private key is supported per host. Note of course that the latter means that user records
+    generated/signed before the key pair is copied in, lose their validity.</para>
+  </refsect1>
+
   <refsect1>
     <title>See Also</title>
     <para>
       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>homed.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>homectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>pam_systemd_home</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
-      <citerefentry><refentrytitle>userdbctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+      <citerefentry><refentrytitle>userdbctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>org.freedesktop.home1</refentrytitle><manvolnum>5</manvolnum></citerefentry>
     </para>
   </refsect1>
 </refentry>