[m-rev.] for review: document and announce the system RNG module

[Julien Fischer]

On Sat, 20 Feb 2021, Zoltan Somogyi wrote:

>
> 2021-02-20 02:10 GMT+11:00 "Julien Fischer" <jfischer at opturion.com>:
>
>> +% For macOS, Cygwin, OpenBSD, NetBSD and versions of FreeBSD from 12 onwards,
>> +% the arc4random() family of functions are used.
>> +% For Windows, the rand_s() function is used.
>> +% For Linux, AIX, Solaris and versions of FreeBSD before 12, randomness is read
>> +% from /dev/urandom;
>
> I would recast these sentences in the active voice, e.g.
>
> For MacOS etc, we use the arc4random family of functions.

Done.

>
>> +% On other operating systems the system RNG is not available.
>
> What do you mean by this? Do you mean that the functions in this module
> will fall back to a insecure source source of randomness, or that they will
> throw an exception?

The latter, I've reworded it to:

    On other operating systems the system RNG is not available; on these
    systems attempting to open a system RNG handle will throw an exception.

The intention with this module is that it provide "high-quality"
randomness; falling back to an insecure source of randomness would
defeat that intention.

> Other than that, the diff is fine.

Thanks for that.

Julien.