cryptsetup/man/integritysetup.8

.TH INTEGRITYSETUP "8" "January 2021" "integritysetup" "Maintenance Commands"
.SH NAME
integritysetup - manage dm-integrity (block level integrity) volumes
.SH SYNOPSIS
.B integritysetup <options> <action> <action args>
.SH DESCRIPTION
.PP
Integritysetup is used to configure dm-integrity managed device-mapper mappings.

Device-mapper integrity target provides read-write transparent integrity
checking of block devices. The dm-integrity target emulates additional data
integrity field per-sector. You can use this additional field directly
with integritysetup utility, or indirectly (for authenticated encryption)
through cryptsetup.

Integritysetup supports these operations:
.PP
\fIformat\fR <device>
.IP
Formats <device> (calculates space and dm-integrity superblock and wipes the device).

\fB<options>\fR can be [\-\-data\-device, \-\-batch\-mode, \-\-no\-wipe, \-\-journal\-size,
\-\-interleave\-sectors, \-\-tag\-size, \-\-integrity, \-\-integrity\-key\-size,
\-\-integrity\-key\-file, \-\-sector\-size, \-\-progress\-frequency, \-\-progress\-json]

.PP
\fIopen\fR <device> <name>
.br
\fIcreate\fR <name> <device> (\fBOBSOLETE syntax\fR)
.IP
Open a mapping with <name> backed by device <device>.

\fB<options>\fR can be [\-\-data\-device, \-\-batch\-mode, \-\-journal\-watermark,
\-\-journal\-commit\-time, \-\-buffer\-sectors, \-\-integrity, \-\-integrity\-key\-size,
\-\-integrity\-key\-file, \-\-integrity\-no\-journal, \-\-integrity\-recalculate,
\-\-integrity\-recalculate-reset,\-\-integrity\-recovery\-mode, \-\-allow\-discards]

.PP
\fIclose\fR <name>
.IP
Removes existing mapping <name>.

For backward compatibility, there is \fBremove\fR command alias
for the \fBclose\fR command.

\fB<options>\fR can be [\-\-deferred] or [\-\-cancel\-deferred]

.PP
\fIstatus\fR <name>
.IP
Reports status for the active integrity mapping <name>.
.PP
\fIdump\fR <device>
.IP
Reports parameters from on-disk stored superblock.

.PP
\fIresize\fR <name>
.IP
Resizes an active mapping <name>.

If \-\-size (in 512-bytes sectors) or \-\-device\-size are not specified,
the size is computed from the underlying device. After resize, the
\fBrecalculating\fR flag is set. If \-\-wipe flag is set and the size of the
device is increased, the newly added section will be wiped.

Increasing the size of integrity volumes is available since the Linux kernel
version 5.7, shrinking should work on older kernels too.

\fB<options>\fR can be [\-\-size, \-\-device\-size, \-\-wipe]

.SH OPTIONS
.TP
.B "\-\-verbose, \-v"
Print more information on command execution.
.TP
.B "\-\-debug"
Run in debug mode with full diagnostic logs. Debug output
lines are always prefixed by '#'.
.TP
.B "\-\-version"
Show the program version.
.TP
.B "\-\-batch\-mode"
Do not ask for confirmation.
.TP
.B "\-\-progress-frequency <seconds>"
Print separate line every <seconds> with wipe progress.
.TP
.B "\-\-progress-json"
Prints wipe progress data in json format suitable mostly for machine processing.
It prints separate line every half second (or based on \fI\-\-progress\-frequency\fR value).
The json output looks as follows during wipe progress (except it's compact single line):
.EX
{
  "device":"/dev/sda"       // backing device or file
  "device_bytes":"8192",    // bytes wiped so far
  "device_size":"44040192", // total bytes to wipe
  "speed":"126877696",      // calculated speed in bytes per second (based on progress so far)
  "eta_ms":"2520012"        // estimated time to finish wipe in milliseconds
  "time_ms":"5561235"       // total time spent wiping device in milliseconds
}
.EE

Note on numbers in json output: Due to json parsers limitations all numbers are represented in a string format
due to need of full 64bit unsigned integers.
.TP
.B "\-\-no\-wipe"
Do not wipe the device after format. A device that is not initially wiped will contain invalid checksums.
.TP
.B "\-\-wipe"
Wipe the newly allocated area after resize to bigger size. If this flag is not set, checksums will be calculated for the data previously stored in the newly allocated area.
.TP
.B "\-\-journal\-size, \-j BYTES"
Size of the journal.
.TP
.B "\-\-interleave\-sectors SECTORS"
The number of interleaved sectors.
.TP
.B "\-\-integrity\-recalculate"
Automatically recalculate integrity tags in kernel on activation.
The device can be used during automatic integrity recalculation but becomes fully
integrity protected only after the background operation is finished.
This option is available since the Linux kernel version 4.19.
.TP
.B "\-\-integrity\-recalculate\-reset"
Restart recalculation from the beginning of the device.
It can be used to change the integrity checksum function.
Note it does not change the tag length.
This option is available since the Linux kernel version 5.13.
.TP
.B "\-\-journal\-watermark PERCENT"
Journal watermark in percents. When the size of the journal exceeds this watermark,
the journal flush will be started.
.TP
.B "\-\-journal\-commit\-time MS"
Commit time in milliseconds. When this time passes (and no explicit flush operation was issued),
the journal is written.
.TP
.B "\-\-tag\-size, \-t BYTES"
Size of the integrity tag per-sector (here the integrity function will store authentication tag).

\fBNOTE:\fR The size can be smaller that output size of the hash function, in that case only
part of the hash will be stored.
.TP
.B "\-\-data\-device"
Specify a separate data device that contains existing data. The <device> then will contain
calculated integrity tags and journal for this data device.
.TP
.B "\-\-sector\-size, \-s BYTES"
Sector size (power of two: 512, 1024, 2048, 4096).
.TP
.B "\-\-buffer\-sectors SECTORS"
The number of sectors in one buffer.

The tag area is accessed using buffers, the large buffer size means that the I/O size will
be larger, but there could be less I/Os issued.
.TP
.B "\-\-integrity, \-I ALGORITHM"
Use internal integrity calculation (standalone mode).
The integrity algorithm can be CRC (crc32c/crc32) or hash function (sha1, sha256).

For HMAC (hmac-sha256) you have also to specify an integrity key and its size.
.TP
.B "\-\-integrity\-key\-size BYTES"
The size of the data integrity key. Maximum is 4096 bytes.
.TP
.B "\-\-integrity\-key\-file FILE"
The file with the integrity key.
.TP
.B "\-\-integrity\-no\-journal, \-D"
Disable journal for integrity device.
.TP
.B "\-\-integrity\-bitmap\-mode. \-B"
Use alternate bitmap mode (available since Linux kernel 5.2)  where dm-integrity uses bitmap
instead of a journal. If a bit in the bitmap is 1, the corresponding region's data and integrity tags
are not synchronized - if the machine crashes, the unsynchronized regions will be recalculated.
The bitmap mode is faster than the journal mode, because we don't have to write the data
twice, but it is also less reliable, because if data corruption happens
when the machine crashes, it may not be detected.
.TP
.B "\-\-bitmap\-sectors\-per\-bit SECTORS"
Number of 512-byte sectors per bitmap bit, the value must be power of two.
.TP
.B "\-\-bitmap\-flush\-time MS"
Bitmap flush time in milliseconds.
.TP

\fBWARNING:\fR
In case of a crash, it is possible that the data and integrity tag doesn't match
if the journal is disabled.
.TP
.B "\-\-integrity\-recovery\-mode. \-R"
Recovery mode (no journal, no tag checking).
.TP

\fBNOTE:\fR The following options are intended for testing purposes only.
Using journal encryption does not make sense without encryption the data,
these options are internally used in authenticated disk encryption with \fBcryptsetup(8)\fR.
.TP
.B "\-\-journal\-integrity ALGORITHM"
Integrity algorithm for journal area.
See \-\-integrity option for detailed specification.
.TP
.B "\-\-journal\-integrity\-key\-size BYTES"
The size of the journal integrity key. Maximum is 4096 bytes.
.TP
.B "\-\-journal\-integrity\-key\-file FILE"
The file with the integrity key.
.TP
.B "\-\-journal\-crypt ALGORITHM"
Encryption algorithm for journal data area.
You can use a block cipher here such as cbc-aes or
a stream cipher, for example, chacha20 or ctr-aes.
.TP
.B "\-\-journal\-crypt\-key\-size BYTES"
The size of the journal encryption key. Maximum is 4096 bytes.
.TP
.B "\-\-journal\-crypt\-key\-file FILE"
The file with the journal encryption key.
.TP
.B "\-\-allow\-discards\fR"
Allow the use of discard (TRIM) requests for the device.
This option is available since the Linux kernel version 5.7.
.TP
.B "\-\-deferred"
Defers device removal in \fIclose\fR command until the last user closes it.
.TP
.B "\-\-cancel\-deferred"
Removes a previously configured deferred device removal in \fIclose\fR command.
.TP
The dm-integrity target is available since Linux kernel version 4.12.
.TP
\fBNOTE:\fR
Format and activation of an integrity device always require superuser
privilege because the superblock is calculated and handled in dm-integrity kernel target.

.SH LEGACY COMPATIBILITY OPTIONS
.TP
\fBWARNING:\fR
Do not use these options until you need compatibility with specific old kernel.
.TP
.B "\-\-integrity\-legacy\-padding"
Use inefficient legacy padding.
.TP
.B "\-\-integrity\-legacy\-hmac"
Use old flawed HMAC calculation (also does not protect superblock).
.TP
.B "\-\-integrity\-legacy\-recalculate"
Allow insecure recalculating of volumes with HMAC keys (recalculation offset in superblock
is not protected).

.SH RETURN CODES
Integritysetup returns 0 on success and a non-zero value on error.

Error codes are:
    1 wrong parameters
    2 no permission
    3 out of memory
    4 wrong device specified
    5 device already exists, or device is busy.

.SH EXAMPLES
Format the device with default standalone mode (CRC32C):

.B "integritysetup format <device>"

Open the device with default parameters:

.B "integritysetup open <device> test"

Format the device in standalone mode for use with HMAC(SHA256):

.B "integritysetup format <device> \-\-tag\-size 32 \-\-integrity hmac\-sha256 \
\-\-integrity\-key\-file <keyfile> \-\-integrity\-key\-size <key_bytes>"

Open (activate) the device with HMAC(SHA256) and HMAC key in file:

.B "integritysetup open <device> test \-\-integrity hmac\-sha256 \
\-\-integrity\-key\-file <keyfile> \-\-integrity\-key\-size <key_bytes>"

Dump dm-integrity superblock information:

.B "integritysetup dump <device>"

.SH REPORTING BUGS
Report bugs, including ones in the documentation, on
the cryptsetup mailing list at <cryptsetup@lists.linux.dev>
or in the 'Issues' section on LUKS website.
Please attach the output of the failed command with the
\-\-debug option added.
.SH AUTHORS
The integritysetup tool is written by Milan Broz <gmazyland@gmail.com>
and is part of the cryptsetup project.
.SH COPYRIGHT
Copyright \(co 2016-2022 Red Hat, Inc.
.br
Copyright \(co 2016-2022 Milan Broz

This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
.SH SEE ALSO
The project website at \fBhttps://gitlab.com/cryptsetup/cryptsetup\fR

The integrity on-disk format specification available at
\fBhttps://gitlab.com/cryptsetup/cryptsetup/wikis/DMIntegrity\fR