I have tested stenc as suggested by sendmoreinfo and it worked well with the LTO-6 drive.
Usage:
Insert a tape and ask the tape drive about its settings:
# stenc -f /dev/nst0 --detail
Generate your 256 bit key and store it:
# stenc -g 256 -k /root/myaes.key -kd Bobs_month_key
Load the key in the LTO tape drive. With --ckod
it will forget the key after tape eject.
# stenc -f /dev/nst0 -e on -k /root/myaes.key -a 1 --ckod
Verify that the drive enabled AES now:
# stenc -f /dev/nst0 --detail
Status for /dev/nst0
--------------------------------------------------
Device Mfg: TANDBERG
Product ID: LTO-6 HH
Product Revision: 3519
Drive Encryption: on
Drive Output: Decrypting
Unencrypted data not outputted
Drive Input: Encrypting
Protecting from raw read
Key Instance Counter: 4
Encryption Algorithm: 1
Drive Key Desc.(uKAD): Bobs_month_key
Volume Encryption: Encrypted and able to decrypt
Protected from raw read
Volume Algorithm: 1
I have prepared a package for Gentoo Linux.