Question - seeding the hw pseudo random number generator

Krzysztof Kozlowski krzk at kernel.org
Sat Mar 18 02:25:54 PDT 2017


Hi,

I looked at Exynos Pseudo Random Nubmer Generator driver
(drivers/char/hw_random/exynos-rng.c) and noticed that it always seeds
the device with jiffies.  Then I looked at few other drivers and found
that they do not seed themself (or at least I couldn't find this).

I think the hw_random API does not provide generic infrastructure for
seeding.

What is the preferred approach for seeding a PRNG device? Use jiffies or
a fixed value?

Or maybe the interface should be abandoned in favor of crypto API?

Best regards,
Krzysztof



More information about the linux-arm-kernel mailing list