[PATCH 2/2] random32: add noise from network and scheduling activity

2020-08-31 Thread Willy Tarreau
With the removal of the interrupt perturbations in previous random32 change (random32: make prandom_u32() output unpredictable), the PRNG has become 100% deterministic again. While SipHash is expected to be way more robust against brute force than the previous Tausworthe LFSR, there's still the ris

Re: [PATCH 2/2] random32: add noise from network and scheduling activity

2020-09-01 Thread Eric Dumazet
On 8/31/20 11:43 PM, Willy Tarreau wrote: > With the removal of the interrupt perturbations in previous random32 > change (random32: make prandom_u32() output unpredictable), the PRNG > has become 100% deterministic again. While SipHash is expected to be > way more robust against brute force tha

Re: [PATCH 2/2] random32: add noise from network and scheduling activity

2020-09-01 Thread Willy Tarreau
Hi Eric, On Tue, Sep 01, 2020 at 12:24:38PM +0200, Eric Dumazet wrote: > There is not much entropy here really : > > 1) dev & txq are mostly constant on a typical host (at least the kind of > hosts that is targeted by > Amit Klein and others in their attacks. > > 2) len is also known by the at