Bug 13518

Summary:	IV calculation for crypto API appears broken
Product:	Gentoo Linux	Reporter:	degs <degs>
Component:	[OLD] Core system	Assignee:	Gentoo Linux bug wranglers <bug-wranglers>
Status:	VERIFIED INVALID
Severity:	normal
Priority:	High
Version:	1.4_rc2
Hardware:	x86
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---

Description degs 2003-01-08 14:40:27 UTC

Hi,
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)

-- degs

Comment 1 degs 2003-01-08 15:33:21 UTC

Ooops: please disregard - not a bug.
apologies
-- degs

Comment 2 degs 2003-01-08 15:34:37 UTC

Not a bug. sorry for spurious report. closing because I cannot delete. Please 
disregard this report.