Re: [kernel-hardening] Re: [PATCH v4 13/13] random: warn when kernel uses unseeded randomness

From: Jason A. Donenfeld
Date: Sun Jun 18 2017 - 15:11:40 EST

On Sun, Jun 18, 2017 at 5:46 PM, Theodore Ts'o <tytso@xxxxxxx> wrote:
> You are effectively proposing that there ought to be a middle range of
> security between prandom_32, get_random_u32/get_random_u64 and
> get_random_bytes(). I think that's going to lead to all sorts of
> complexity and bugs from people not understanding when they should use
> get_random_u32 vs get_random_bytes versus prandom_u32. And then we'll
> end up needing to audit all of the callsites for get_random_u32() so
> they don't violate this new usage rule that you are proposing.

I agree with you wholeheartedly.

get_random_* provides the secure random numbers.
prandom_* provides the insecure random numbers.

Introducing some kind of middle ground will result in needless
complexity and inevitable bugs.