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From:   Florian Weimer <fweimer@redhat.com>
To:     "Theodore Ts'o" <tytso@mit.edu>
Cc:     Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>,
        Rich Felker <dalias@libc.org>,
        Yann Droneaud <ydroneaud@opteya.com>,
        "Jason A. Donenfeld" <Jason@zx2c4.com>, libc-alpha@sourceware.org,
        linux-crypto@vger.kernel.org, Michael@phoronix.com, jann@thejh.net
Subject: Re: arc4random - are you sure we want these?
In-Reply-To: <YuEwR0bJhOvRtmFe@mit.edu> (Theodore Ts'o's message of "Wed, 27
        Jul 2022 08:32:07 -0400")
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Date:   Wed, 27 Jul 2022 14:49:57 +0200
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* Theodore Ts'o:

> But even if you didn't take the latest kernels, I think you will find
> that if you actually benchmark how many queries per second a real-life
> secure web server or VPN gateway, even the original 5.15.0 /dev/random
> driver was plenty fast enough for real world cryptographic use cases.

The idea is to that arc4random() is suitable in pretty much all places
that have historically used random() (outside of deterministic
simulations).  Straight calls to getrandom are much, much slower than
random(), and it's not even the system call overhead.

Thanks,
Florian