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authorLinus Torvalds <torvalds@linux-foundation.org>2008-04-25 12:33:49 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-25 12:33:49 -0700
commit6f97b220f414e3599ea5374905ba6d0dc47d63b0 (patch)
tree79b268ea6efcd417d923fdbc1aed7bc0fce15554 /Documentation
parent4b7227ca321ccf447cdc04538687c895db8b77f5 (diff)
parente3dcc5a387fc38e9c3c6c4f857cd9a7f71a8553a (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm
* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: (24 commits) dm crypt: add documentation dm: remove md argument from specific_minor dm table: remove unused dm_create_error_table dm table: drop void suspend_targets return dm: unplug queues in threads dm raid1: use timer dm: move include files dm kcopyd: rename dm: expose macros dm kcopyd: remove redundant client counting dm kcopyd: private mempool dm kcopyd: per device dm log: make module use tracking internal dm log: move register functions dm log: clean interface dm kcopyd: clean interface dm io: clean interface dm io: rename error to error_bits dm snapshot: store pointer to target instance dm log: move dirty region log code into separate module ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/device-mapper/dm-crypt.txt52
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diff --git a/Documentation/device-mapper/dm-crypt.txt b/Documentation/device-mapper/dm-crypt.txt
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+++ b/Documentation/device-mapper/dm-crypt.txt
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+dm-crypt
+=========
+
+Device-Mapper's "crypt" target provides transparent encryption of block devices
+using the kernel crypto API.
+
+Parameters: <cipher> <key> <iv_offset> <device path> <offset>
+
+<cipher>
+ Encryption cipher and an optional IV generation mode.
+ (In format cipher-chainmode-ivopts:ivmode).
+ Examples:
+ des
+ aes-cbc-essiv:sha256
+ twofish-ecb
+
+ /proc/crypto contains supported crypto modes
+
+<key>
+ Key used for encryption. It is encoded as a hexadecimal number.
+ You can only use key sizes that are valid for the selected cipher.
+
+<iv_offset>
+ The IV offset is a sector count that is added to the sector number
+ before creating the IV.
+
+<device path>
+ This is the device that is going to be used as backend and contains the
+ encrypted data. You can specify it as a path like /dev/xxx or a device
+ number <major>:<minor>.
+
+<offset>
+ Starting sector within the device where the encrypted data begins.
+
+Example scripts
+===============
+LUKS (Linux Unified Key Setup) is now the preferred way to set up disk
+encryption with dm-crypt using the 'cryptsetup' utility, see
+http://luks.endorphin.org/
+
+[[
+#!/bin/sh
+# Create a crypt device using dmsetup
+dmsetup create crypt1 --table "0 `blockdev --getsize $1` crypt aes-cbc-essiv:sha256 babebabebabebabebabebabebabebabe 0 $1 0"
+]]
+
+[[
+#!/bin/sh
+# Create a crypt device using cryptsetup and LUKS header with default cipher
+cryptsetup luksFormat $1
+cryptsetup luksOpen $1 crypt1
+]]