Re: [PATCH] Improve mutt's random data generator.

Kevin J. McCarthy wrote in
 <aeqgaBYoQ7jxtkj6@qinghai>:
 |On Thu, Apr 23, 2026 at 10:05:09AM +0200, Greg KH wrote:
 |>On Thu, Apr 23, 2026 at 02:10:31PM +0800, Kevin J. McCarthy wrote:
 |>> Use getrandom() if available, or else arc4random_buf().  Only fall
 |>> back to using the built-in PRNG if those aren't found on the system.

Btw it seems to me mutt_ssl.c and that RAND handling could see an
iteration (no one uses that .rnd file anymore, RAND_egd() is very
very much dead, and all that).

But anyway, if linked against that, one could use RAND_bytes(),
too.  Especially with LibreSSL, where it always succeeds (i think
last i looked it abort()ed on failure).

With OpenSSL they went over certain terrible corners, brought in
and dropped RAND_DRBG_set_reseed_defaults() again, now it is
really, really sad, *but*, you know, Kurt Roeckx said

  [we do not]
  * ASSERT RAND_status() ("Since you always have to check RAND_bytes's
  * return value now, RAND_status is mostly useless.",
  * [email protected]), so we have not that many options
  * on what to do.  Since OSs will try hard to serve, a simple sleep
  * may be it, so do that */

Ie we now sleep 250 millies if RAND_bytes() fails (not 200 because
some 20 years ago certain kernels busy looped to satisfy such
sleeps, if i got that right), anticipating that reseeding will
succeed with the next iteration, under the hood, for sure.
(I offer RAND_bytes() only as an option.)

Configuring the RAND with OpenSSL 3.0.0 and above is a horror trip
(and likely not doable at all with the CRNG behind RAND_bytes(),
but i stopped reading that, really.  In my opinion it is grazy,
what they do .. especially given that certain jitter "random
daemons" generate thousands of bits of entropy in a fraction of
a second, which then serves them as they succeed to reseed).

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)