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Date:   Sun, 20 Feb 2022 19:40:17 -0800
From:   Eric Biggers <ebiggers@kernel.org>
To:     "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc:     linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
        tytso@mit.edu, linux@dominikbrodowski.net
Subject: Re: [PATCH v2 8/9] random: use hash function for crng_slow_load()
Message-ID: <YhMJoYykeNTVpz7w@sol.localdomain>
References: <20220209011919.493762-1-Jason@zx2c4.com>
 <20220209011919.493762-9-Jason@zx2c4.com>
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On Wed, Feb 09, 2022 at 02:19:18AM +0100, Jason A. Donenfeld wrote:
> Since we have a hash function that's really fast, and the goal of
> crng_slow_load() is reportedly to "touch all of the crng's state", we
> can just hash the old state together with the new state and call it a
> day. This way we dont need to reason about another LFSR or worry about
> various attacks there. This code is only ever used at early boot and
> then never again.
> 
> Cc: Theodore Ts'o <tytso@mit.edu>
> Cc: Dominik Brodowski <linux@dominikbrodowski.net>
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> ---
>  drivers/char/random.c | 42 +++++++++++++++---------------------------
>  1 file changed, 15 insertions(+), 27 deletions(-)

Reviewed-by: Eric Biggers <ebiggers@google.com>

- Eric