Re: Random Sequence Numbers

From: Peter Jeremy (peter.jeremyat_private)
Date: Wed Feb 09 2000 - 14:06:08 PST

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On 2000-Feb-09 20:27:08 +1100, Omachonu Ogali <oogaliat_private> wrote:
>I don't know if anyone else attempted, but I whipped up a little patch for
>FreeBSD that randomizes the sequence/acknowledgment numbers sent by TCP
>instead of incrementing it by one each time. Apply using 'patch'.

Note that the patch is using libkern/random().  This function is a
simple, multiplicative PNRG with 32-bits of state (all of which is
`leaked' via its return value.  Whilst the change might be better than
a simple increment/decrement, I don't believe it provides any real
security (especially in view of the %=2 operations).

Peter

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