ipv6 connection hash function wanted ...

[Oliver Fromme]

Max Laier wrote:
 > David Malone wrote:
 > > Assuming you don't want to use one of the standard cryptographic
 > > ones (which I can imagine being a bit slow for something done
 > > per-packet), then one option might be to use a simpler hash that
 > > is keyed. Choose the key at boot/module load time and make it hard
 > > to produce collisions unless you know the key.
 > 
 > That's exactly what I am looking for ... now I need someone[tm] - with
 > better Math-Knowledge than mine - to write such a thing down in a simple
 > formula :-) i.e. take those bits from there and there and XOR them with
 > your canary yada-yada-yada ...

In that case, simply use crc32 (available from libkern.h)
and xor with a random key generated at boot time.  crc32
is fast to calculate and has the properties that you need.

Best regards
   Oliver

--
Oliver Fromme,  secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing
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