Commit Graph

37 Commits

Author SHA1 Message Date
Mark Murray
84d4f509f0 Major speedup to /dev/random and the kernel thread that reseeds it.
There is no more TAILQ fifo to harvest the entropy; instead, there
is a circular buffer of constant size (changeable by macro) that
pretty dramatically improves the speed and fixes potential slowdowns-
by-locking.

Also gone are a slew of malloc(9) and free(9) calls; all harvesting
buffers are static.

All-in-all, this is a good performance improvement.

Thanks-to:	msmith for the circular buffer concept-code.
2000-12-02 18:40:16 +00:00
Mark Murray
17c9715049 Fix safety-net code. While technically a bug, I'm delighted to see
that it has never (apparently) been invoked.

Submitted by:	ache
2000-11-26 09:58:18 +00:00
Mark Murray
5d4e386e64 D'uh. The explicit reseed was happening at the wrong security/privelige
levels.
2000-11-25 20:08:07 +00:00
Mark Murray
5063615923 Greatly improve the boot-up unblocking time of the entropy device. 2000-11-25 19:13:29 +00:00
Mark Murray
caccf5c400 More comment changing. Keep documentation in one place. 2000-11-25 18:00:54 +00:00
Mark Murray
24242537f8 Correct a comment. This represents a very minor policy change of my
intentions with this code.
2000-11-25 17:58:11 +00:00
Mark Murray
e73a42f8fb Stop explicitly using nanotime(9) and use the new get_cyclecounter(9)
call instead.

This makes a pretty dramatic difference to the amount of work that
the harvester needs to do - it is much friendlier on the system.
(80386 and 80486 class machines will notice little, as the new
get_cyclecounter() call is a wrapper round nanotime(9) for them).
2000-11-25 17:09:01 +00:00
Poul-Henning Kamp
cf9fa8e725 Move suser() and suser_xxx() prototypes and a related #define from
<sys/proc.h> to <sys/systm.h>.

Correctly document the #includes needed in the manpage.

Add one now needed #include of <sys/systm.h>.
Remove the consequent 48 unused #includes of <sys/proc.h>.
2000-10-29 16:06:56 +00:00
Poul-Henning Kamp
53ce36d17a Remove unneeded #include <sys/proc.h> lines. 2000-10-29 13:57:19 +00:00
Mark Murray
5f3431b5ad As the blocking model has seems to be troublesome for many, disable
it for now with an option.

This option is already deprecated, and will be removed when the
entropy-harvesting code is fast enough to warrant it.
2000-10-27 06:06:04 +00:00
John Baldwin
35e0e5b311 Catch up to moving headers:
- machine/ipl.h -> sys/ipl.h
- machine/mutex.h -> sys/mutex.h
2000-10-20 07:58:15 +00:00
Peter Wemm
93d88e0056 Attempt to fix the random read blocking. The old code slept at
priority "0" and without PCATCH, so it was uninterruptable.  And
even when it did wake up after entropy arrived, it exited after the
wakeup without actually reading the freshly arrived entropy.  I
sent this to Mark before but it seems he is in transit.
Mark: feel free to replace this if it gets in your way.
2000-10-18 10:39:18 +00:00
Mark Murray
a6278a2a42 After some complaints about the dir names, the random device is
now in dirs called sys/*/random/ instead of sys/*/randomdev/*.

Introduce blocking, but only at startup; the random device will
block until the first reseed happens to prevent clients from
using untrustworthy output.

Provide a read_random() call for the rest of the kernel so that
the entropy device does not need to be present. This means that
things like IPX no longer need to have "device random" hardcoded
into thir kernel config. The downside is that read_random() will
provide very poor output until the entropy device is loaded and
reseeded. It is recommended that developers do NOT use the
read_random() call; instead, they should use arc4random() which
internally uses read_random().

Clean up the mutex and locking code a bit; this makes it possible
to unload the module again.
2000-10-14 10:59:56 +00:00
Mark Murray
4a8612fd41 Remove unneeded includes.
Submitted by:	phk
2000-09-21 06:23:16 +00:00
Robert Watson
c4ff4a8467 Include <sys/proc.h> to silence suser() compiler warning.
Approved by:	markm
2000-09-18 20:42:04 +00:00
John Baldwin
606f8eb27a Remove the mtx_t, witness_t, and witness_blessed_t types. Instead, just
use struct mtx, struct witness, and struct witness_blessed.

Requested by:	bde
2000-09-14 20:15:16 +00:00
Mark Murray
d0d519348d The "struct proc" argument to read_random was ill-conceived, and a
hangover from previous experimentation. Remove it. This will clean
up gratuitous needs for forward references and other namespace
pollution.
Moaned about by:	bde
Brought to my attention by:	bp
2000-09-12 13:13:22 +00:00
John Baldwin
ecbcd538a4 Move the prototypes for random_set_wakeup* from yarrow.c to yarrow.h so that
both yarrow.c and harvest.c can use them.

Approved by:	markm
2000-09-11 19:31:28 +00:00
John Baldwin
2ed0f9191a - Use RFHIGHPID when creating the kthread to get a more sensible pid.
- Don't fake walking a tailq.  Instead, use a while loop that pulls items
  off the head of the queue while the queue is not empty.
2000-09-11 04:09:08 +00:00
Mark Murray
4d87a031c0 Large upgrade to the entropy device; mainly inspired by feedback
from many folk.

o The reseed process is now a kthread. With SMPng, kthreads are
  pre-emptive, so the annoying jerkiness of the mouse is gone.

o The data structures are protected by mutexes now, not splfoo()/splx().

o The cryptographic routines are broken out into their own subroutines.
  this facilitates review, and possible replacement if that is ever
  found necessary.

Thanks to:		kris, green, peter, jasone, grog, jhb
Forgotten to thank:	You know who you are; no offense intended.
2000-09-10 13:52:19 +00:00
Mark Murray
7aa4389a6c o Fix a horrible bug where small reads (< 8 bytes) would return the
wrong bytes.

o Improve the public interface; use void* instead of char* or u_int64_t
  to pass arbitrary data around.
Submitted by:	kris ("horrible bug")
2000-07-25 21:18:47 +00:00
Mark Murray
c90a8fc9a5 Clean this up with some BDE-inspired fixes.
o Make the comments KNF-compliant.
o Use nanotime instead of getnanotime; the manpage lies about the
  kern.timecounter.method - it has been removed.
o Fix the ENTROPYSOURCE const permanently.
o Make variable names more consistent.
o Make function prototypes more consistent.

Some more needs to be done; to follow.
2000-07-23 11:08:16 +00:00
Mark Murray
720a3741cf Add randomness write functionality. This does absolutely nothing for
entropy estimation, but causes an immediate reseed after the input
(read in sizeof(u_int64_t) chunks) is "harvested".

This will be used in the reboot "reseeder", coming in another
commit. This can be used very effectively at any time you think
your randomness is compromised; something like

# (ps -gauxwww; netstat -an; dmesg; vmstat -c10 1) > /dev/random

will give the attacker something to think about.
2000-07-17 12:23:04 +00:00
Mark Murray
4d0e6f79d6 Storing to a pointer is (effectively) atomic; no need to protect this
with splhigh(). However, the entropy-harvesting routine needs pretty
serious irq-protection, as it is called out of irq handlers etc.

Clues given by:	bde
2000-07-11 19:37:25 +00:00
Mark Murray
7978f67e28 I think I need to move the newly static variables to the random_state
structure; remind myself in the cooments. Also regroup all the Yarrow
variables at the top of the variable list; they are "special".
(no functional change).
2000-07-11 18:35:33 +00:00
Brian Feldman
87a478de7b One should never allocate 4-kilobyte structs and such on the interrupt
stack.  It's bad for your machine's health.

Make the two huge structs in reseed() static to prevent crashes.  This
is the bug that people have been running into and panic()ing on for the
past few days.

Reviewed by:	phk
2000-07-11 06:47:38 +00:00
Mark Murray
fb15ada363 Provide more splsofttq() protection for the reseed task (running out of
taskqueue_swi).
2000-07-10 06:40:23 +00:00
Mark Murray
43975bd56c Make sure that tasks (running out of taskqueue_swi at splsofttq)
are not interfered with by the harvester.
2000-07-09 16:00:31 +00:00
Mark Murray
585ebe2b41 Yarrow tweaks; separate the fast and slow reseed tasks so that they don't
stomp on each other; provide constant names (as enums) for the harvester
to use (makes it more self-documenting).
2000-07-09 11:52:12 +00:00
Mark Murray
769afb047c Fix bug with a vraiable that needs to be per-process, not static;
fix formatting of long macros.

Pointed out by:	bde
2000-07-09 11:49:07 +00:00
Mark Murray
c9ec235ca1 Add entropy gathering code. This will work whether the module is
compiled in or loaded.
2000-07-07 09:03:59 +00:00
Mark Murray
d44f401738 Staticize a variable.
This fixes the case where linking randomdev into the kernel statically
can cause panics at shutdown time.

Reported by:	sos
2000-06-28 18:51:15 +00:00
Mark Murray
1f67cd8737 I am guilty of an act of ommission. There is no longer a /dev/urandom
device with Yarrow, and although I coded for that in dev/MAKEDEV, I forgot
to _tell_ folks.

This commit adds back the /dev/urandom device (as a duplicate) of /dev/random,
until such time as it can be properly announced.

This will help the openssl users quite a lot.
2000-06-27 09:38:40 +00:00
Mark Murray
d4262fb0dd style(9) fixes from BDE.
We shouldn't use '#include ""', rather '#include<>'.
2000-06-26 12:14:20 +00:00
Mark Murray
d147096d0f Fix include for non-module case.
Thanks-to:	SOS
2000-06-25 20:03:44 +00:00
Mark Murray
39d9385710 Fix include for the non-module case.
Thanks-to:	SOS
2000-06-25 19:00:20 +00:00
Mark Murray
4db9ae91ff New machine-independant /dev/random driver.
This is work-in-progress, and the entropy-gathering routines are not
yet present. As such, this should be viewed as a pretty reasonable
PRNG with _ABSOLUTELY_NO_ security!!

Entropy gathering will be the subject of ongoing work.

This is written as a module, and as such is unloadable, but there is
no refcounting done. I would like to use something like device_busy(9)
to achieve this (eventually).

Lots of useful ideas from:	bde, phk, Jeroen van Gelderen

Reviewed by:	dfr
2000-06-25 08:38:58 +00:00