Re: Should Emacs provide a uuid function?

[Chong Yidong <cyd@stupidchicken.com>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>>> (defun secure-random-bytes (n)
>>> (let ((file (cond
>>> ((file-exists-p "/dev/random")  "/dev/random")
>>> ((file-exists-p "/dev/urandom") "/dev/urandom")
>>> (t (error "Secure random device not available")))))
>
>> Feh.  Using platform-dependent interfaces in Lisp is not the Emacs
>> way, in my book.  How about a primitive which would read from
>> /dev/random or /dev/urandom if they are available, or use other
>> methods if they are not?
>
> FWIW, I don't think there's anything wrong with writing the
> platform-dependent code in Elisp rather than in C.  I generally prefer
> code to be written in Elisp when possible and when it's not introducing
> a performance problem.

I'm not sure we should introduce a separate function, though.  It makes
more sense to improve the existing `random' primitive, making it return
a random number (via /dev/random or /dev/urandom or GnuTLS) rather than
a pseudo-random number when possible.

We could add an optional arg to `random' that says that if no secure
random source is available, signal an error instead of falling back on
the old method.