Messages in this thread | | | From | Stephan Mueller <> | Subject | Re: [PATCH v4 0/5] /dev/random - a new approach | Date | Tue, 21 Jun 2016 20:05:01 +0200 |
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Am Dienstag, 21. Juni 2016, 13:54:13 schrieb Austin S. Hemmelgarn:
Hi Austin,
> On 2016-06-21 13:23, Stephan Mueller wrote: > > Am Dienstag, 21. Juni 2016, 13:18:33 schrieb Austin S. Hemmelgarn: > > > > Hi Austin, > > > >>> You have to trust the host for anything, not just for the entropy in > >>> timings. This is completely invalid argument unless you can present a > >>> method that one guest can manipulate timings in other guest in such a > >>> way that _removes_ the inherent entropy from the host. > >> > >> When dealing with almost any type 2 hypervisor, it is fully possible for > >> a user other than the one running the hypervisor to manipulate > >> scheduling such that entropy is reduced. This does not imply that the > > > > Please re-read the document: Jitter RNG does not rest on scheduling. > > If you are running inside a VM, your interrupt timings depend on the
The RNG does not rest on interrupts either.
> hpyervisor's scheduling, period. You may not directly rely on > scheduling from the OS you are running on, but if you are doing anything > timing related in a VM, you are at the mercy of the scheduling used by > the hypervisor and whatever host OS that may be running on. > > In the attack I"m describing, the malicious user is not manipulating the > guest OS's scheduling, they are manipulating the host system's scheduling.
Ciao Stephan
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