Messages in this thread | | | From | Denis Vlasenko <> | Subject | Re: [PATCH 8/14] random: Remove SA_SAMPLE_RANDOM from USB gadget drivers | Date | Sat, 6 May 2006 14:07:02 +0300 |
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On Friday 05 May 2006 19:42, Matt Mackall wrote: > Remove SA_SAMPLE_RANDOM from USB gadget drivers > > There's no a priori reason to think that USB device interrupts will > contain "entropy" as defined/required by /dev/random. In fact, most > operations will be streaming and bandwidth- or CPU-limited. > /dev/random needs unpredictable inputs such as human interaction or > chaotic physical processes like turbulence manifested in disk seek > times.
You may remove SA_SAMPLE_RANDOM from disk interrupts on the same grounds, because flash-based "IDE" drives have no seek. Indeed, with careful choice of components, setup, and placement of sniffing equipment you may construct a case where you can predict interrupt times.
But it's too artificial to matter in real life.
Come on, let's get real. A few low bits of TSC are random enough (for just about any interrupt source).
Attackers will probably look for easier ways to hack your crypto than predicting /dev/random. -- vda - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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