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Bug 13518 - IV calculation for crypto API appears broken
Summary: IV calculation for crypto API appears broken
Alias: None
Product: Gentoo Linux
Classification: Unclassified
Component: [OLD] Core system (show other bugs)
Hardware: x86 Linux
: High normal (vote)
Assignee: Gentoo Linux bug wranglers
Depends on:
Reported: 2003-01-08 14:40 UTC by degs
Modified: 2003-02-04 19:42 UTC (History)
0 users

See Also:
Package list:
Runtime testing required: ---


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