HDD Encryption/Decryption

GEOM bswap16

• Swaps bytes in every 16-bit word
• Similar to dm-bswap16 on Linux.

http://gitorious.ps3dev.net/ps3freebsd/geom-bswap16

http://gitorious.ps3dev.net/ps3freebsd/geom-bswap16-lib

Test

kldload geom_bswap16.ko

mdconfig -a -t vnode -f ~/test.bin -u 0

geom bswap16 create /dev/md0

hexdump -C /dev/md0

00000000  bb aa dd cc 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000020  ee ff 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000030  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00100000

hexdump -C /dev/md0.bswap16

00000000  aa bb cc dd 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000020  ff ee 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000030  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00100000

Links

• https://www.dan.me.uk/blog/2012/05/05/full-disk-encryption-in-freebsd-9-x-well-almost/