Commit Graph

10 Commits

Author SHA1 Message Date
phk
775372e52e Slight overhaul of arc4random() and friends.
One bug fixed:  Use getmicrouptime() to trigger reseeds so that we
cannot be tricked by a clock being stepped backwards.

Express parameters in natural units and with natural names.

Don't use struct timeval more than we need to.

Various stylistic and readability polishing.

Introduce arc4rand(void *ptr, u_int len, int reseed) function which
returns a stream of pseudo-random bytes, observing the automatic
reseed criteria as well as allowing forced reseeds.

Rewrite arc4random() in terms of arc4rand().

Sponsored by:   DARPA & NAI Labs.
2002-10-11 13:13:08 +00:00
bde
ab9b31c6e0 Fixed some typos, verboseness and misformatting in comments. 2001-08-30 12:30:58 +00:00
silby
b4c97b9269 Minor improvements to arc4random():
- Decrease reseeding interval from every 64 to every 16384 runs
  to reduce entropy usage.
- Add time based reseeding.  (Every 5 minutes.)
- Throw away the first 256 words of output as suggested in
  "Weaknesses in the Key Scheduling Algorithm of RC4."

Reviewed by: Mark Murray
MFC After: jkh says ok
2001-08-30 01:15:25 +00:00
markm
5a9b5f7c13 Recouple arc4random(9) to the entropy device. This works whether the
entropy device is loaded or not.

If the entropy device is NOT loaded, the the quality of perturbations
supplied by this will suffer.
2000-12-02 16:23:54 +00:00
jhb
f2e0710ab9 Back out previous revision now that sys/random.h is properly fixed. 2000-09-11 19:34:04 +00:00
jhb
5581cc0e46 Add #include's of sys/proc.h and sys/param.h to silence a warning. 2000-09-11 05:51:58 +00:00
markm
64f9169412 Comment out unavailable call. This needs to be revisited when the entropy
device is complete.
Reviewed by:	dfr
2000-06-25 10:15:58 +00:00
dan
2caf8b3c1a In the extremely miniscule chance that read_random returns <= 0, don't try
and use that return code as a modulus (panics are bad, mmmkay?)
1999-11-29 19:23:35 +00:00
dan
08f9eb57a7 Address the concerns of the ``randomness'' of the initial PRNG. Now, we
use bits from /dev/random to stir the S-box.  Also add an internal counter to
keep the S-box stirred on a regular basis.

Reviewed by: msmith
1999-11-28 23:39:49 +00:00
dan
c08e8bdab0 Introduce OpenBSD-like Random PIDs. Controlled by a sysctl knob
(kern.randompid), which is currently defaulted off.  Use ARC4 (RC4) for our
random number generation, which will not get me executed for violating
crypto laws; a Good Thing(tm).

Reviewed and Approved by: bde, imp
1999-11-28 17:51:09 +00:00