fields are mandatory, the remaining two are
optional.</para>
+ <para>Setting up encrypted block devices using this file
+ supports three encryption modes: LUKS, TrueCrypt and plain.
+ See <citerefentry><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ for more information about each mode. When no mode is specified
+ in the options field and the block device contains a LUKS
+ signature, it is opened as a LUKS device; otherwise, it is
+ assumed to be in raw dm-crypt (plain mode) format.</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
+ underlying block device or file, 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>
+ UUID.</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
+ is set to <literal>none</literal> or <literal>-</literal>,
+ the password has to be manually entered during system boot.
+ Otherwise, the field is interpreted as a absolute 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
comma-delimited list of options. The following
options are recognized:</para>
- <variablelist class='crypttab-options'>
+ <variablelist class='fstab-options'>
+
<varlistentry>
- <term><varname>cipher=</varname></term>
+ <term><option>discard</option></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>
+ <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><option>cipher=</option></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>
+ <term><option>hash=</option></term>
- <listitem><para>Specifies the key size
- in bits; see
+ <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>
+ for possible values and the default value of
+ this option.</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>keyfile-offset=</option></term>
+
+ <listitem><para>Specifies the number of bytes to
+ skip at the start of the key file. 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>
+ <term><option>keyfile-size=</option></term>
<listitem><para>Specifies the maximum number
- of bytes to read from the keyfile; see
+ of bytes to read from the key file. 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>
+ for possible values and the default value of
+ this option. This option is ignored in plain
+ encryption mode, as the key file 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
+ <term><option>key-slot=</option></term>
+
+ <listitem><para>Specifies the key slot to
+ compare the passphrase or key against.
+ If the key slot does not match the given
+ passphrase or key, but another would, the
+ setup of the device will fail regardless.
+ This option implies <option>luks</option>. See
<citerefentry><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
- for possible values and the default
- value of this option.</para></listitem>
+ for possible values. The default is to try
+ all key slots in sequential order.</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>luks</option></term>
+
+ <listitem><para>Force LUKS mode. When this mode
+ is used, the following options are ignored since
+ they are provided by the LUKS header on the
+ device: <option>cipher=</option>,
+ <option>hash=</option>,
+ <option>size=</option>.</para></listitem>
+ </varlistentry>
<varlistentry>
- <term><varname>hash=</varname></term>
+ <term><option>noauto</option></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>
+ <listitem><para>This device will not be
+ automatically unlocked on boot.</para></listitem>
</varlistentry>
<varlistentry>
- <term><varname>tries=</varname></term>
+ <term><option>nofail</option></term>
- <listitem><para>Specifies the maximum
- number of times the user is queried
- for a password.</para></listitem>
+ <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 does not show up.</para></listitem>
</varlistentry>
<varlistentry>
- <term><varname>verify</varname></term>
+ <term><option>plain</option></term>
- <listitem><para> If the encryption
- password is read from console, it has
- to be entered twice (to prevent
- typos). </para></listitem>
+ <listitem><para>Force plain encryption mode.</para></listitem>
</varlistentry>
<varlistentry>
- <term><varname>read-only</varname></term><term><varname>readonly</varname></term>
+ <term><option>read-only</option></term><term><option>readonly</option></term>
- <listitem><para>Set up the encrypted
- block device in read-only
- mode.</para></listitem>
+ <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>
+ <term><option>size=</option></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>luks</varname></term>
+ <term><option>swap</option></term>
+
+ <listitem><para>The encrypted block device will
+ be used as a swap device, and will be formatted
+ accordingly after setting up the encrypted
+ block device, with
+ <citerefentry project='man-pages'><refentrytitle>mkswap</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
+ This option implies <option>plain</option>.</para>
+
+ <para>WARNING: Using the <option>swap</option>
+ 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>
- <listitem><para>Force LUKS mode.</para></listitem>
+ <varlistentry>
+ <term><option>tcrypt</option></term>
+
+ <listitem><para>Use TrueCrypt encryption mode.
+ When this mode is used, the following options are
+ ignored since they are provided by the TrueCrypt
+ header on the device or do not apply:
+ <option>cipher=</option>,
+ <option>hash=</option>,
+ <option>keyfile-offset=</option>,
+ <option>keyfile-size=</option>,
+ <option>size=</option>.</para>
+
+ <para>When this mode is used, the passphrase is
+ read from the key file given in the third field.
+ Only the first line of this file is read,
+ excluding the new line character.</para>
+
+ <para>Note that the TrueCrypt format uses both
+ passphrase and key files to derive a password
+ for the volume. Therefore, the passphrase and
+ all key files need to be provided. Use
+ <option>tcrypt-keyfile=</option> to provide
+ the absolute path to all key files. When using
+ an empty passphrase in combination with one or
+ more key files, use <literal>/dev/null</literal>
+ as the password file in the third field.</para></listitem>
</varlistentry>
<varlistentry>
- <term><varname>plain</varname></term>
+ <term><option>tcrypt-hidden</option></term>
- <listitem><para>Force plain encryption
- mode.</para></listitem>
+ <listitem><para>Use the hidden TrueCrypt volume.
+ This option implies <option>tcrypt</option>.</para>
+
+ <para>This will map the hidden volume that is
+ inside of the volume provided in the second
+ field. Please note that there is no protection
+ for the hidden volume if the outer volume is
+ mounted instead. See
+ <citerefentry><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ for more information on this limitation.</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. A timeout of 0 waits indefinitely
- (which is the
- default).</para></listitem>
+ <term><option>tcrypt-keyfile=</option></term>
+
+ <listitem><para>Specifies the absolute path to a
+ key file to use for a TrueCrypt volume. This
+ implies <option>tcrypt</option> and can be
+ used more than once to provide several key
+ files.</para>
+
+ <para>See the entry for <option>tcrypt</option>
+ on the behavior of the passphrase and key files
+ when using TrueCrypt encryption mode.</para></listitem>
</varlistentry>
<varlistentry>
- <term><varname>noauto</varname></term>
+ <term><option>tcrypt-system</option></term>
- <listitem><para> This device will not
- be automatically unlocked on
- boot. </para></listitem>
+ <listitem><para>Use TrueCrypt in system
+ encryption mode. This option implies
+ <option>tcrypt</option>.</para></listitem>
</varlistentry>
<varlistentry>
- <term><varname>nofail</varname></term>
+ <term><option>timeout=</option></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>
+ <listitem><para>Specifies the timeout for
+ querying for a password. If no unit is
+ specified, seconds is used. Supported units are
+ s, ms, us, min, h, d. A timeout of 0 waits
+ indefinitely (which is the default).</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>
+ <term><option>x-systemd.device-timeout=</option></term>
+
+ <listitem><para>Specifies how long
+ systemd should wait for a device to
+ show up before giving up on the
+ entry. The argument is a time in
+ seconds or explicitly specifified
+ units of <literal>s</literal>,
+ <literal>min</literal>,
+ <literal>h</literal>,
+ <literal>ms</literal>.
+ </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>
+ <term><option>tmp</option></term>
+
+ <listitem><para>The encrypted block device will
+ be prepared for using it as <filename>/tmp</filename>;
+ it will be formatted using
+ <citerefentry project='man-pages'><refentrytitle>mke2fs</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
+ This option implies <option>plain</option>.</para>
+
+ <para>WARNING: Using the <option>tmp</option>
+ 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><option>tries=</option></term>
+
+ <listitem><para>Specifies the maximum number of
+ times the user is queried for a password.
+ The default is 3. If set to 0, the user is
+ queried for a password indefinitely.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>verify</option></term>
+
+ <listitem><para> If the encryption password is
+ read from console, it has to be entered twice to
+ prevent typos.</para></listitem>
+ </varlistentry>
+
</variablelist>
<para>At early boot and when the system manager
- configuration is reloaded this file is translated into
+ configuration is reloaded, this file is translated into
native systemd units
by <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
</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>
+ <para>Set up four encrypted block devices. One using
+ LUKS for normal storage, another one for usage as a swap
+ device and two TrueCrypt volumes.</para>
+
+ <programlisting>luks UUID=2505567a-9e27-4efe-a4d5-15ad146c258b
+swap /dev/sda7 /dev/urandom swap
+truecrypt /dev/sda2 /etc/container_password tcrypt
+hidden /mnt/tc_hidden /dev/null tcrypt-hidden,tcrypt-keyfile=/etc/keyfile</programlisting>
</example>
</refsect1>
<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>
+ <citerefentry project='man-pages'><refentrytitle>mkswap</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>mke2fs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
</para>
</refsect1>
~ianmdlvl / elogind.git / blobdiff