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author | Anthony G. Basile <blueness@gentoo.org> | 2012-11-15 10:10:41 -0500 |
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committer | Anthony G. Basile <blueness@gentoo.org> | 2012-11-15 10:10:41 -0500 |
commit | 2944f347d087ff24ec808e4b70fe104a772a97a0 (patch) | |
tree | a5de4fbefe16ef359a526442fb41251f123399d5 /man/crypttab.xml | |
parent | 678b0b89572768b21d8b74360d55b75b233799c4 (diff) | |
parent | d025f1e4dca8fc1436aff76f9e6185fe3e728daa (diff) |
Fork of Original Code Base: anongit.freedesktop.org/systemd
This is the initial fork of the code base from freedsktop.org.
The code is provided here as a reference of the initial starting
point and for possible future checkouts after a large portion
of this code is removed.
Merge git://anongit.freedesktop.org/systemd/systemd
Diffstat (limited to 'man/crypttab.xml')
-rw-r--r-- | man/crypttab.xml | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/man/crypttab.xml b/man/crypttab.xml new file mode 100644 index 0000000000..2a839944dc --- /dev/null +++ b/man/crypttab.xml @@ -0,0 +1,313 @@ +<?xml version="1.0"?> +<!--*-nxml-*--> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> +<!-- + This file is part of systemd. + + Copyright 2012 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. + + This is based on crypttab(5) from Fedora's initscripts package, which in + turn is based on Debian's version. + + The Red Hat version has been written by Miloslav Trmac <mitr@redhat.com>. + +--> +<refentry id="crypttab"> + + <refentryinfo> + <title>crypttab</title> + <productname>systemd</productname> + + <authorgroup> + <author> + <contrib>Documentation</contrib> + <firstname>Miloslav</firstname> + <surname>Trmac</surname> + <email>mitr@redhat.com</email> + </author> + <author> + <contrib>Documentation</contrib> + <firstname>Lennart</firstname> + <surname>Poettering</surname> + <email>lennart@poettering.net</email> + </author> + </authorgroup> + </refentryinfo> + + <refmeta> + <refentrytitle>crypttab</refentrytitle> + <manvolnum>5</manvolnum> + </refmeta> + + <refnamediv> + <refname>crypttab</refname> + <refpurpose>Configuration for encrypted block devices</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <para><filename>/etc/crypttab</filename></para> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para>The <filename>/etc/crypttab</filename> file + describes encrypted block devices that are set up + during system boot.</para> + + <para>Empty lines and lines starting with the # + character are ignored. Each of the remaining lines + describes one encrypted block device, fields on the + line are delimited by white space. The first two + fields are mandatory, the remaining two are + optional.</para> + + <para>The first field contains the name of the + resulting encrypted block device; the device is set up + within <filename>/dev/mapper/</filename>.</para> + + <para>The second field contains a path to the + underlying block device, or a specification of a block + device via <literal>UUID=</literal> followed by the + UUID. If the block device contains a LUKS signature, + it is opened as a LUKS encrypted partition; otherwise + it is assumed to be a raw dm-crypt partition.</para> + + <para>The third field specifies the encryption + password. If the field is not present or the password + is set to none, the password has to be manually + entered during system boot. Otherwise the field is + interpreted as a path to a file containing the + encryption password. For swap encryption + <filename>/dev/urandom</filename> or the hardware + device <filename>/dev/hw_random</filename> can be used + as the password file; using + <filename>/dev/random</filename> may prevent boot + completion if the system does not have enough entropy + to generate a truly random encryption key.</para> + + <para>The fourth field, if present, is a + comma-delimited list of options. The following + options are recognized:</para> + + <variablelist> + <varlistentry> + <term><varname>cipher=</varname></term> + + <listitem><para>Specifies the cipher + to use; see + <citerefentry><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry> + for possible values and the default + value of this option. A cipher with + unpredictable IV values, such as + <literal>aes-cbc-essiv:sha256</literal>, + is recommended. </para></listitem> + </varlistentry> + + + <varlistentry> + <term><varname>size=</varname></term> + + <listitem><para>Specifies the key size + in bits; see + <citerefentry><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry> + for possible values and the default + value of this + option. </para></listitem> + </varlistentry> + + + <varlistentry> + <term><varname>keyfile-size=</varname></term> + + <listitem><para>Specifies the maximum number + of bytes to read from the keyfile; see + <citerefentry><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry> + for possible values and the default + value of this option. This option is ignored + in plain encryption mode, as the keyfile-size is then given by the key size.</para></listitem> + </varlistentry> + + + <varlistentry> + <term><varname>keyfile-offset=</varname></term> + + <listitem><para>Specifies the number + of bytes to skip at the start of + the keyfile; see + <citerefentry><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry> + for possible values and the default + value of this option.</para></listitem> + </varlistentry> + + + <varlistentry> + <term><varname>hash=</varname></term> + + <listitem><para>Specifies the hash to + use for password hashing; see + <citerefentry><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry> for possible values and + the default value of this + option. </para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>tries=</varname></term> + + <listitem><para>Specifies the maximum + number of times the user is queried + for a password.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>verify</varname></term> + + <listitem><para> If the encryption + password is read from console, it has + to be entered twice (to prevent + typos). </para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>read-only</varname></term> + + <listitem><para>Set up the encrypted + block device in read-only + mode.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>allow-discards</varname></term> + + <listitem><para>Allow discard requests + to be passed through the encrypted + block device. This improves + performance on SSD storage but has + security + implications.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>luks</varname></term> + + <listitem><para>Force LUKS mode.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>plain</varname></term> + + <listitem><para>Force plain encryption + mode.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>timeout=</varname></term> + + <listitem><para>Specify the timeout + for querying for a password. If no + unit is specified seconds is used. + Supported units are s, ms, + us, min, h, d.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>noauto</varname></term> + + <listitem><para> This device will not + be automatically unlocked on + boot. </para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>nofail</varname></term> + + <listitem><para>The system will not + wait for the device to show up and be + unlocked at boot, and not fail the + boot if it doesn't show + up.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>swap</varname></term> + + <listitem><para> The encrypted block + device will be used as a swap + partition, and will be formatted as a + swap partition after setting up the + encrypted block device, with + <citerefentry><refentrytitle>mkswap</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> + + <para>WARNING: Using the + <varname>swap</varname> option will + destroy the contents of the named + partition during every boot, so make + sure the underlying block device is + specified + correctly. </para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>tmp</varname></term> + + <listitem><para>The encrypted block + device will be prepared for using it + as <filename>/tmp</filename> + partition: it will be formatted using + <citerefentry><refentrytitle>mke2fs</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> + + <para>WARNING: Using the + <varname>tmp</varname> option will + destroy the contents of the named + partition during every boot, so make + sure the underlying block device is + specified + correctly. </para></listitem> + </varlistentry> + </variablelist> + + <para>At early boot and when the system manager + configuration is reloaded this file is translated into + native systemd units + by <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> + </refsect1> + + <refsect1> + <title>Example</title> + <example> + <title>/etc/crypttab example</title> + <para>Set up two encrypted block devices with + LUKS: one normal one for storage, and another + one for usage as swap device.</para> + + <programlisting>luks-2505567a-9e27-4efe-a4d5-15ad146c258b UUID=2505567a-9e27-4efe-a4d5-15ad146c258b - timeout=0 +swap /dev/sda7 /dev/urandom swap</programlisting> + </example> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>mkswap</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>mke2fs</refentrytitle><manvolnum>8</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |