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Message-ID: <78977ba5-3814-1b5d-c58f-eec58ace3c44@linaro.org>
Date:   Tue, 26 Jul 2022 10:11:24 -0300
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Subject: Re: [PATCH v2] arc4random: simplify design for better safety
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To:     "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc:     libc-alpha@sourceware.org, Florian Weimer <fweimer@redhat.com>,
        =?UTF-8?Q?Cristian_Rodr=c3=adguez?= <crrodriguez@opensuse.org>,
        Paul Eggert <eggert@cs.ucla.edu>, linux-crypto@vger.kernel.org
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From:   Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
Organization: Linaro
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On 26/07/22 09:47, Jason A. Donenfeld wrote:
> Hi Adhemerval,
> 
> On Tue, Jul 26, 2022 at 09:34:57AM -0300, Adhemerval Zanella Netto wrote:
>> kernel newer than 3.17) it means some syscall filtering, and I am not sure
>> we should need to actually handle it.
> 
> One thing to keep in mind is that people who use CUSE-based /dev/urandom
> implementations might not like this, as it means they'd also have to
> intercept getrandom() rather than just ENOSYS'ing it. But maybe that's
> fine. I don't know of anyone actually doing this in the real world at
> the moment.
> 

I think it is a fair assumption that if you trying to implement your own
character device in userland, we should know the implications for the
environment.  From glibc standpoint, and I would for this whole thread,
we should assume that getrandom is de-facto API for entropy.