From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- Documentation/device-mapper/dm-crypt.txt | 57 ++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 Documentation/device-mapper/dm-crypt.txt (limited to 'Documentation/device-mapper/dm-crypt.txt') diff --git a/Documentation/device-mapper/dm-crypt.txt b/Documentation/device-mapper/dm-crypt.txt new file mode 100644 index 00000000..6b5c42db --- /dev/null +++ b/Documentation/device-mapper/dm-crypt.txt @@ -0,0 +1,57 @@ +dm-crypt +========= + +Device-Mapper's "crypt" target provides transparent encryption of block devices +using the kernel crypto API. + +Parameters: + + + Encryption cipher and an optional IV generation mode. + (In format cipher[:keycount]-chainmode-ivopts:ivmode). + Examples: + des + aes-cbc-essiv:sha256 + twofish-ecb + + /proc/crypto contains supported crypto modes + + + Key used for encryption. It is encoded as a hexadecimal number. + You can only use key sizes that are valid for the selected cipher. + + + Multi-key compatibility mode. You can define keys and + then sectors are encrypted according to their offsets (sector 0 uses key0; + sector 1 uses key1 etc.). must be a power of two. + + + The IV offset is a sector count that is added to the sector number + before creating the IV. + + + 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 :. + + + 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://code.google.com/p/cryptsetup/ + +[[ +#!/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 +]] -- cgit v1.2.3