add basic LUKS header support

[nmatt0]

This PR adds basic support for detecting LUKS headers:
https://en.wikipedia.org/wiki/Linux_Unified_Key_Setup

Currently I'm only parsing the version and the hash function because those are the two fields that are in the same offsets in versions 1 and 2 of LUKS.

After that version 1 and 2 start to diverge, and will take some more work to parse them separately.

Test data was generated as follows:

dd if=/dev/zero of=test1.bin count=100000 bs=1024
dd if=/dev/zero of=test2.bin count=100000 bs=1024
cryptsetup luksFormat --type luks1 test1.bin
cryptsetup luksFormat --type luks2 test2.bin
echo -e "LUKS\xba\xbe\x00\xff" > test3.bin # FALSE POSITIVE TEST (invalid version number)

Output for LUKS vesion 1:

                 /home/nmatt/work/research/binwalkv3/testfw/test1.bin
--------------------------------------------------------------------------------------
DECIMAL                            HEXADECIMAL                        DESCRIPTION
--------------------------------------------------------------------------------------
0                                  0x0                                LUKS header, 
                                                                      version: 1, 
                                                                      hash fn: 
                                                                      sha256
--------------------------------------------------------------------------------------

Analyzed 1 file for 78 file signatures (180 magic patterns) in 40.0 milliseconds

Output for LUKS vesion 2:

                 /home/nmatt/work/research/binwalkv3/testfw/test2.bin
--------------------------------------------------------------------------------------
DECIMAL                            HEXADECIMAL                        DESCRIPTION
--------------------------------------------------------------------------------------
0                                  0x0                                LUKS header, 
                                                                      version: 2, 
                                                                      hash fn: 
                                                                      sha256
--------------------------------------------------------------------------------------

Analyzed 1 file for 78 file signatures (180 magic patterns) in 349.0 milliseconds

test3.bin did not get flagged as a LUKS header. (correctly)

Thanks,
Matt

[devttys0]

Thank you!

[devttys0]

This has been merged into the master branch