SYSTEMD-CRYPTSETUP-GENERAsystemd-cryptsetup-genSYSTEMD-CRYPTSETUP-GENERATOR(8)
NAME
systemd-cryptsetup-generator - Unit generator for /etc/crypttab
SYNOPSIS
/lib/systemd/system-generators/systemd-cryptsetup-generator
DESCRIPTION
systemd-cryptsetup-generator is a generator that translates
/etc/crypttab into native systemd units early at boot and when
configuration of the system manager is reloaded. This will create
systemd-cryptsetup@.service(8) units as necessary.
systemd-cryptsetup-generator implements systemd.generator(7).
KERNEL COMMAND LINE
systemd-cryptsetup-generator understands the following kernel command
line parameters:
luks=, rd.luks=
Takes a boolean argument. Defaults to "yes". If "no", disables the
generator entirely. rd.luks= is honored only in the initrd while
luks= is honored by both the main system and in the initrd.
luks.crypttab=, rd.luks.crypttab=
Takes a boolean argument. Defaults to "yes". If "no", causes the
generator to ignore any devices configured in /etc/crypttab
(luks.uuid= will still work however). rd.luks.crypttab= is honored
only in initrd while luks.crypttab= is honored by both the main
system and the initrd.
luks.uuid=, rd.luks.uuid=
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
/etc/crypttab. This option may be specified more than once in order
to set up multiple devices. rd.luks.uuid= is honored only in the
initrd, while luks.uuid= is honored by both the main system and the
initrd.
If /etc/crypttab contains entries with the same UUID, then the
name, keyfile and options specified there will be used. Otherwise,
the device will have the name "luks-UUID".
If /etc/crypttab exists, only those UUIDs specified on the kernel
command line will be activated in the initrd or the real root.
luks.name=, rd.luks.name=
Takes a LUKS super block UUID followed by an "=" and a name. This
implies rd.luks.uuid= or luks.uuid= and will additionally make the
LUKS device given by the UUID appear under the provided name.
This parameter is the analogue of the first crypttab(5) field
volume-name.
rd.luks.name= is honored only in the initrd, while luks.name= is
honored by both the main system and the initrd.
luks.data=, rd.luks.data=
Takes a LUKS super block UUID followed by a "=" and a block device
specification for device hosting encrypted data.
For those entries specified with rd.luks.uuid= or luks.uuid=, the
data device will be set to the one specified by rd.luks.data= or
luks.data= of the corresponding UUID.
LUKS data device parameter is useful for specifying encrypted data
devices with detached headers specified in luks.options entry
containing "header=" argument. For example,
rd.luks.uuid=b40f1abf-2a53-400a-889a-2eccc27eaa40
rd.luks.options=b40f1abf-2a53-400a-889a-2eccc27eaa40=header=/path/to/luks.hdr
rd.luks.data=b40f1abf-2a53-400a-889a-2eccc27eaa40=/dev/sdx. Hence,
in this case, we will attempt to unlock LUKS device assembled from
data device "/dev/sdx" and LUKS header (metadata) put in
"/path/to/luks.hdr" file. This syntax is for now only supported on
a per-device basis, i.e. you have to specify LUKS device UUID.
This parameter is the analogue of the second crypttab(5) field
encrypted-device.
rd.luks.data= is honored only in the initrd, while luks.data= is
honored by both the main system and in the initrd.
luks.key=, rd.luks.key=
Takes a password file name as argument or a LUKS super block UUID
followed by a "=" and a password file name.
For those entries specified with rd.luks.uuid= or luks.uuid=, the
password file will be set to the one specified by rd.luks.key= or
luks.key= of the corresponding UUID, or the password file that was
specified without a UUID.
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,
rd.luks.uuid=b40f1abf-2a53-400a-889a-2eccc27eaa40
rd.luks.key=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 "keydev". This syntax is for now
only supported on a per-device basis, i.e. you have to specify LUKS
device UUID.
This parameter is the analogue of the third crypttab(5) field
key-file.
rd.luks.key= is honored only in the initrd, while luks.key= is
honored by both the main system and in the initrd.
luks.options=, rd.luks.options=
Takes a LUKS super block UUID followed by an "=" and a string of
options separated by commas as argument. This will override the
options for the given UUID.
If only a list of options, without an UUID, is specified, they
apply to any UUIDs not specified elsewhere, and without an entry in
/etc/crypttab.
This parameter is the analogue of the fourth crypttab(5) field
options.
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 luks.data with detached LUKS header found in
"header=" argument. For example,
rd.luks.uuid=b40f1abf-2a53-400a-889a-2eccc27eaa40
rd.luks.options=b40f1abf-2a53-400a-889a-2eccc27eaa40=header=/luks.hdr:LABEL=hdrdev
rd.luks.data=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 "hdrdev", and look for "luks.hdr" 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.
rd.luks.options= is honored only by initial RAM disk (initrd) while
luks.options= is honored by both the main system and the initrd.
SEE ALSO
systemd(1), crypttab(5), systemd-cryptsetup@.service(8), systemd-
cryptenroll(1), cryptsetup(8), systemd-fstab-generator(8)
systemd 252 SYSTEMD-CRYPTSETUP-GENERATOR(8)
Generated by dwww version 1.15 on Wed Jun 26 00:55:46 CEST 2024.