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From: Peter Maydell <peter.maydell@linaro.org>
Date: Fri, 17 Feb 2017 14:11:12 +0000
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Subject: Re: [Qemu-devel] [PATCH] bcm2835_rng: Use qcrypto_random_bytes()
 rather than rand()
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To: "Daniel P. Berrange" <berrange@redhat.com>
Cc: qemu-arm <qemu-arm@nongnu.org>, QEMU Developers <qemu-devel@nongnu.org>, "patches@linaro.org" <patches@linaro.org>, Marcin Chojnacki <marcinch7@gmail.com>, =?UTF-8?B?QWxleCBCZW5uw6ll?= <alex.bennee@linaro.org>

On 17 February 2017 at 14:05, Daniel P. Berrange <berrange@redhat.com> wrote:
> On Fri, Feb 17, 2017 at 12:22:39PM +0000, Peter Maydell wrote:
>> We should probably improve crypto/random-platform.c to use
>> getentropy() if available, which would fix the "BSD or OSX
>> host and not using gcrypt or gnutls" case which I think is
>> the most likely cause of qcrypto_random_bytes() failing.
>
> randopm-platform.c currentl uses /dev/urandom or /dev/random,
> so that should work when GNUTLS/gcrypt are both disabled at
> build time.

Ah, and OSX and the BSDs have those devices. (I had
mistakenly assumed they were a linuxism.)

> What would fail, is uses it from a chroot with an empty /dev
> of course.

Yes; replacing the rand() in linux-user/main.c would require
this I think (unless we're willing to fall back to rand ;-))

thanks
-- PMM