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<refentry id="systemd.system-credentials">

  <refentryinfo>
    <title>systemd.system-credentials</title>
    <productname>systemd</productname>
  </refentryinfo>

  <refmeta>
    <refentrytitle>systemd.system-credentials</refentrytitle>
    <manvolnum>7</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>systemd.system-credentials</refname>
    <refpurpose>System Credentials</refpurpose>
  </refnamediv>

  <refsect1>
    <title>Description</title>

    <para><ulink url="https://systemd.io/CREDENTIALS">System and Service Credentials</ulink> are data objects
    that may be passed into booted systems or system services as they are invoked. They can be acquired from
    various external sources, and propagated into the system and from there into system services. Credentials
    may optionally be encrypted with a machine-specific key and/or locked to the local TPM2 device, and are
    only decrypted when the consuming service is invoked.</para>

    <para>System credentials may be used to provision and configure various aspects of the system. Depending
    on the consuming component credentials are only used on initial invocations or are needed for all
    invocations.</para>

    <para>Credentials may be used for any kind of data, binary or text, and may carry passwords, secrets,
    certificates, cryptographic key material, identity information, configuration, and more.</para>
  </refsect1>

  <refsect1>
    <title>Well known system credentials</title>

    <variablelist>
      <varlistentry>
        <term><varname>firstboot.keymap</varname></term>
        <listitem>
          <para>The console key mapping to set (e.g. <literal>de</literal>).  Read by
          <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
          and only honoured if no console keymap has been configured before.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>firstboot.locale</varname></term>
        <term><varname>firstboot.locale-message</varname></term>
        <listitem>
          <para>The system locale to set (e.g. <literal>de_DE.UTF-8</literal>). Read by
          <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
          and only honoured if no locale has been configured before. <varname>firstboot.locale</varname> sets
          <literal>LANG</literal>, while <varname>firstboot.locale-message</varname> sets
          <literal>LC_MESSAGES</literal>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>firstboot.timezone</varname></term>
        <listitem>
          <para>The system timezone to set (e.g. <literal>Europe/Berlin</literal>).  Read by
          <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
          and only honoured if no system timezone has been configured before.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>login.issue</varname></term>
        <listitem>
          <para>The data of this credential is written to
          <filename>/etc/issue.d/50-provision.conf</filename>, if the file doesn't exist yet.
          <citerefentry project='man-pages'><refentrytitle>agetty</refentrytitle><manvolnum>8</manvolnum></citerefentry>
          reads this file and shows its contents at the login prompt of terminal logins. See
          <citerefentry project='man-pages'><refentrytitle>issue</refentrytitle><manvolnum>5</manvolnum></citerefentry>
          for details.</para>

          <para>Consumed by <filename>/usr/lib/tmpfiles.d/provision.conf</filename>, see
          <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>login.motd</varname></term>
        <listitem>
          <para>The data of this credential is written to <filename>/etc/motd.d/50-provision.conf</filename>,
          if the file doesn't exist yet.
          <citerefentry project='man-pages'><refentrytitle>pam_motd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
          reads this file and shows its contents as "message of the day" during terminal logins. See
          <citerefentry project='man-pages'><refentrytitle>motd</refentrytitle><manvolnum>5</manvolnum></citerefentry>
          for details.</para>

          <para>Consumed by <filename>/usr/lib/tmpfiles.d/provision.conf</filename>, see
          <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>network.hosts</varname></term>
        <listitem>
          <para>The data of this credential is written to <filename>/etc/hosts</filename>, if the file
          doesn't exist yet. See
          <citerefentry project='man-pages'><refentrytitle>hosts</refentrytitle><manvolnum>5</manvolnum></citerefentry>
          for details.</para>

          <para>Consumed by <filename>/usr/lib/tmpfiles.d/provision.conf</filename>, see
          <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>network.dns</varname></term>
        <term><varname>network.search_domains</varname></term>
        <listitem>
          <para>DNS server information and search domains. Read by
          <citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>passwd.hashed-password.root</varname></term>
        <term><varname>passwd.plaintext-password.root</varname></term>
        <listitem>
          <para>May contain the password (either in UNIX hashed format, or in plaintext) for the root users.
          Read by both
          <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
          and
          <citerefentry><refentrytitle>systemd-sysusers</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
          and only honoured if no root password has been configured before.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>passwd.shell.root</varname></term>
        <listitem>
          <para>The path to the shell program (e.g. <literal>/bin/bash</literal>) for the root user.  Read by
          both
          <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
          and
          <citerefentry><refentrytitle>systemd-sysusers</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
          and only honoured if no root shell has been configured before.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>ssh.authorized_keys.root</varname></term>
        <listitem>
          <para>The data of this credential is written to <filename>/root/.ssh/authorized_keys</filename>, if
          the file doesn't exist yet. This allows provisioning SSH access for the system's root user.</para>

          <para>Consumed by <filename>/usr/lib/tmpfiles.d/provision.conf</filename>, see
          <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>sysusers.extra</varname></term>
        <listitem>
          <para>Additional
          <citerefentry><refentrytitle>sysusers.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
          lines to process during boot.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>sysctl.extra</varname></term>
        <listitem>
          <para>Additional
          <citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> lines
          to process during boot.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>tmpfiles.extra</varname></term>
        <listitem>
          <para>Additional
          <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
          lines to process during boot.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>vconsole.keymap</varname></term>
        <term><varname>vconsole.keymap_toggle</varname></term>
        <term><varname>vconsole.font</varname></term>
        <term><varname>vconsole.font_map</varname></term>
        <term><varname>vconsole.font_unimap</varname></term>
        <listitem>
          <para>Console settings to apply, see
          <citerefentry><refentrytitle>systemd-vconsole-setup.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> for details.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>vmm.notify_socket</varname></term>
        <listitem>
          <para>Contains a <constant>AF_VSOCK</constant> or <constant>AF_UNIX</constant> address where to
          send a <constant>READY=1</constant> notification datagram when the system has finished booting. See
          <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry> for
          more information. Note that in case the hypervisor does not support <constant>SOCK_DGRAM</constant>
          over <constant>AF_VSOCK</constant>, <constant>SOCK_SEQPACKET</constant> will be tried instead. The
          credential payload for <constant>AF_VSOCK</constant> should be in the form
          <literal>vsock:CID:PORT</literal>.</para>

          <para>This feature is useful for hypervisors/VMMs or other processes on the host to receive a
          notification via VSOCK when a virtual machine has finished booting.</para>
        </listitem>
      </varlistentry>

    </variablelist>
  </refsect1>

  <refsect1>
      <title>See Also</title>
      <para>
        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
        <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>
      </para>
  </refsect1>

</refentry>
