Minor code reorganization was required, but the only functional
change was that the first 1024 bytes of output are thrown out
after each reseed, rather than just the initial seed.
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.
- 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
(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
