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Date: Tue, 24 Feb 2015 11:51:52 +0200
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To: Sammy Kaye Powers <me@sammyk.me>
Cc: PHP Internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] [RFC] [DISCUSSION] Reliable user-land CSPRNG
From: narf@devilix.net (Andrey Andreev)

Hi,

On Tue, Feb 24, 2015 at 8:36 AM, Sammy Kaye Powers <me@sammyk.me> wrote:
> The RFC to add a user-land API for an easy-to-use and reliable CSPRNG in
> PHP is up for discussion: https://wiki.php.net/rfc/easy_userland_csprng
>
> This proposes adding two methods: `random_bytes()` and `random_int()` that
> return cryptographically secure pseudo-random data.
>
> This has been quite a team effort so far and would love to hear your
> feedback! :)

I noticed that the patch checks for /dev/arandom availability first,
and I'm pretty sure that on systems that have it, /dev/urandom simply
redirects to /dev/urandom, so that might be a bit redundant ... Maybe
Leigh can say more about this if I'm missing something.

Also, you don't need 100s of lines of code to write the same thing in
userland ... you need ~30 lines, your Facebook SDK example is just
over-complicated. I'm sure everybody will agree that this is a feature
that PHP needs, so I think you should rather focus on explaining that
it's better than leaving it to userland implementations that may screw
up a lot of details.

And finally, a suggestion to remove the default $length value of 16
for random_bytes() - it just happens to be what you need for i.e. an
AES-128 IV, but other than that it doesn't make sense to have a
default length.

Otherwise - great! I'm really looking forward to this, and many others
surely do as well. I've got no doubt that the RFC will pass and I
intend to write a compat package for use in pre-PHP7 environments, to
ease the new API's adoption.

Cheers,
Andrey.