I don't know much about cryptograhpy so this may not be a bug.
Using gentoo 2.4.19 kernel with cryptoapi
# dd if=/dev/zero of=/dev/hdxy
# losetup -e twofish -k 256 /dev/loop/0 /dev/hdxy
# hexdump /dev/loop/0
<gives key-dependent repeating pattern of period 0x200 bytes>
Shouldn't the block IV mean that each block in the loop device gets a different
key and hence each block of zeros should decrypt to differently?
Looks like twofish is running in CBC over each block but the IV is the same for
each block. This would be a BAD THING(tm)
Ooops: please disregard - not a bug.
Not a bug. sorry for spurious report. closing because I cannot delete. Please
disregard this report.