fix up r314327 (MFC of r292782): sha2 -> sha512 in sys/modules/random

MFC r263219: add sha256c.c to the various modules that included sha2.c...

MFC: Add extra files to the KLD random.ko module to allow it to load.

Approved by: re (kib)

Merge from project branch via main. Uninteresting commits are trimmed.

Refactor of /dev/random device. Main points include:

* Userland seeding is no longer used. This auto-seeds at boot time
on PC/Desktop setups; this may need some tweeking and intelligence
from those folks setting up embedded boxes, but the work is believed
to be minimal.

* An entropy cache is written to /entropy (even during installation)
and the kernel uses this at next boot.

* An entropy file written to /boot/entropy can be loaded by loader(8)

* Hardware sources such as rdrand are fed into Yarrow, and are no
longer available raw.

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r256240 | des | 2013-10-09 21:14:16 +0100 (Wed, 09 Oct 2013) | 4 lines

Add a RANDOM_RWFILE option and hide the entropy cache code behind it.
Rename YARROW_RNG and FORTUNA_RNG to RANDOM_YARROW and RANDOM_FORTUNA.
Add the RANDOM_* options to LINT.

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r256239 | des | 2013-10-09 21:12:59 +0100 (Wed, 09 Oct 2013) | 2 lines

Define RANDOM_PURE_RNDTEST for rndtest(4).

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r256204 | des | 2013-10-09 18:51:38 +0100 (Wed, 09 Oct 2013) | 2 lines

staticize struct random_hardware_source

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r256203 | markm | 2013-10-09 18:50:36 +0100 (Wed, 09 Oct 2013) | 2 lines

Wrap some policy-rich code in 'if NOTYET' until we can thresh out
what it really needs to do.

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r256184 | des | 2013-10-09 10:13:12 +0100 (Wed, 09 Oct 2013) | 2 lines

Re-add /dev/urandom for compatibility purposes.

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r256182 | des | 2013-10-09 10:11:14 +0100 (Wed, 09 Oct 2013) | 3 lines

Add missing include guards and move the existing ones out of the
implementation namespace.

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r256168 | markm | 2013-10-08 23:14:07 +0100 (Tue, 08 Oct 2013) | 10 lines

Fix some just-noticed problems:

o Allow this to work with "nodevice random" by fixing where the
MALLOC pool is defined.

o Fix the explicit reseed code. This was correct as submitted, but
in the project branch doesn't need to set the "seeded" bit as this
is done correctly in the "unblock" function.

o Remove some debug ifdeffing.

o Adjust comments.

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r256159 | markm | 2013-10-08 19:48:11 +0100 (Tue, 08 Oct 2013) | 6 lines

Time to eat crow for me.

I replaced the sx_* locks that Arthur used with regular mutexes;
this turned out the be the wrong thing to do as the locks need to
be sleepable. Revert this folly.

# Submitted by: Arthur Mesh <arthurmesh@gmail.com> (In original diff)

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r256138 | des | 2013-10-08 12:05:26 +0100 (Tue, 08 Oct 2013) | 10 lines

Add YARROW_RNG and FORTUNA_RNG to sys/conf/options.

Add a SYSINIT that forces a reseed during proc0 setup, which happens
fairly late in the boot process.

Add a RANDOM_DEBUG option which enables some debugging printf()s.

Add a new RANDOM_ATTACH entropy source which harvests entropy from the
get_cyclecount() delta across each call to a device attach method.

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r256135 | markm | 2013-10-08 07:54:52 +0100 (Tue, 08 Oct 2013) | 8 lines

Debugging. My attempt at EVENTHANDLER(multiuser) was a failure; use
EVENTHANDLER(mountroot) instead.

This means we can't count on /var being present, so something will
need to be done about harvesting /var/db/entropy/... .

Some policy now needs to be sorted out, and a pre-sync cache needs
to be written, but apart from that we are now ready to go.

Over to review.

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r256094 | markm | 2013-10-06 23:45:02 +0100 (Sun, 06 Oct 2013) | 8 lines

Snapshot.

Looking pretty good; this mostly works now. New code includes:

* Read cached entropy at startup, both from files and from loader(8)
preloaded entropy. Failures are soft, but announced. Untested.

* Use EVENTHANDLER to do above just before we go multiuser. Untested.

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r256088 | markm | 2013-10-06 14:01:42 +0100 (Sun, 06 Oct 2013) | 2 lines

Fix up the man page for random(4). This mainly removes no-longer-relevant
details about HW RNGs, reseeding explicitly and user-supplied
entropy.

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r256087 | markm | 2013-10-06 13:43:42 +0100 (Sun, 06 Oct 2013) | 6 lines

As userland writing to /dev/random is no more, remove the "better
than nothing" bootstrap mode.

Add SWI harvesting to the mix.

My box seeds Yarrow by itself in a few seconds! YMMV; more to follow.

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r256086 | markm | 2013-10-06 13:40:32 +0100 (Sun, 06 Oct 2013) | 11 lines

Debug run. This now works, except that the "live" sources haven't
been tested. With all sources turned on, this unlocks itself in
a couple of seconds! That is no my box, and there is no guarantee
that this will be the case everywhere.

* Cut debug prints.

* Use the same locks/mutexes all the way through.

* Be a tad more conservative about entropy estimates.

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r256084 | markm | 2013-10-06 13:35:29 +0100 (Sun, 06 Oct 2013) | 5 lines

Don't use the "real" assembler mnemonics; older compilers may not
understand them (like when building CURRENT on 9.x).

# Submitted by: Konstantin Belousov <kostikbel@gmail.com>

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r256081 | markm | 2013-10-06 10:55:28 +0100 (Sun, 06 Oct 2013) | 12 lines

SNAPSHOT.

Simplify the malloc pools; We only need one for this device.

Simplify the harvest queue.

Marginally improve the entropy pool hashing, making it a bit faster
in the process.

Connect up the hardware "live" source harvesting. This is simplistic
for now, and will need to be made rate-adaptive.

All of the above passes a compile test but needs to be debugged.

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r256042 | markm | 2013-10-04 07:55:06 +0100 (Fri, 04 Oct 2013) | 25 lines

Snapshot. This passes the build test, but has not yet been finished or debugged.

Contains:

* Refactor the hardware RNG CPU instruction sources to feed into
the software mixer. This is unfinished. The actual harvesting needs
to be sorted out. Modified by me (see below).

* Remove 'frac' parameter from random_harvest(). This was never
used and adds extra code for no good reason.

* Remove device write entropy harvesting. This provided a weak
attack vector, was not very good at bootstrapping the device. To
follow will be a replacement explicit reseed knob.

* Separate out all the RANDOM_PURE sources into separate harvest
entities. This adds some secuity in the case where more than one
is present.

* Review all the code and fix anything obviously messy or inconsistent.
Address som review concerns while I'm here, like rename the pseudo-rng
to 'dummy'.

# Submitted by: Arthur Mesh <arthurmesh@gmail.com> (the first item)

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r255319 | markm | 2013-09-06 18:51:52 +0100 (Fri, 06 Sep 2013) | 4 lines

Yarrow wants entropy estimations to be conservative; the usual idea
is that if you are certain you have N bits of entropy, you declare
N/2.

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r255075 | markm | 2013-08-30 18:47:53 +0100 (Fri, 30 Aug 2013) | 4 lines

Remove short-lived idea; thread to harvest (eg) RDRAND enropy into the
usual harvest queues. It was a nifty idea, but too heavyweight.

# Submitted by: Arthur Mesh <arthurmesh@gmail.com>

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r255071 | markm | 2013-08-30 12:42:57 +0100 (Fri, 30 Aug 2013) | 4 lines

Separate out the Software RNG entropy harvesting queue and thread
into its own files.

# Submitted by: Arthur Mesh <arthurmesh@gmail.com>

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r254934 | markm | 2013-08-26 20:07:03 +0100 (Mon, 26 Aug 2013) | 2 lines

Remove the short-lived namei experiment.

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r254928 | markm | 2013-08-26 19:35:21 +0100 (Mon, 26 Aug 2013) | 2 lines

Snapshot; Do some running repairs on entropy harvesting. More needs
to follow.

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r254927 | markm | 2013-08-26 19:29:51 +0100 (Mon, 26 Aug 2013) | 15 lines

Snapshot of current work;

1) Clean up namespace; only use "Yarrow" where it is Yarrow-specific
or close enough to the Yarrow algorithm. For the rest use a neutral
name.

2) Tidy up headers; put private stuff in private places. More could
be done here.

3) Streamline the hashing/encryption; no need for a 256-bit counter;
128 bits will last for long enough.

There are bits of debug code lying around; these will be removed
at a later stage.

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r254784 | markm | 2013-08-24 14:54:56 +0100 (Sat, 24 Aug 2013) | 39 lines

1) example (partially humorous random_adaptor, that I call "EXAMPLE")
* It's not meant to be used in a real system, it's there to show how
the basics of how to create interfaces for random_adaptors. Perhaps
it should belong in a manual page

2) Move probe.c's functionality in to random_adaptors.c
* rename random_ident_hardware() to random_adaptor_choose()

3) Introduce a new way to choose (or select) random_adaptors via tunable
"rngs_want" It's a list of comma separated names of adaptors, ordered
by preferences. I.e.:
rngs_want="yarrow,rdrand"

Such setting would cause yarrow to be preferred to rdrand. If neither of
them are available (or registered), then system will default to
something reasonable (currently yarrow). If yarrow is not present, then
we fall back to the adaptor that's first on the list of registered
adaptors.

4) Introduce a way where RNGs can play a role of entropy source. This is
mostly useful for HW rngs.

The way I envision this is that every HW RNG will use this
functionality by default. Functionality to disable this is also present.
I have an example of how to use this in random_adaptor_example.c (see
modload event, and init function)

5) fix kern.random.adaptors from
kern.random.adaptors: yarrowpanicblock
to
kern.random.adaptors: yarrow,panic,block

6) add kern.random.active_adaptor to indicate currently selected
adaptor:
root@freebsd04:~ # sysctl kern.random.active_adaptor
kern.random.active_adaptor: yarrow

# Submitted by: Arthur Mesh <arthurmesh@gmail.com>

Submitted by: Dag-Erling Smørgrav <des@FreeBSD.org>, Arthur Mesh <arthurmesh@gmail.com>
Reviewed by: des@FreeBSD.org
Approved by: re (delphij)
Approved by: secteam (des,delphij)

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Bring in some behind-the-scenes development, mainly By Arthur Mesh,
the rest by me.

o Namespace cleanup; the Yarrow name is now restricted to where it
really applies; this is in anticipation of being augmented or
replaced by Fortuna in the future. Fortuna is mentioned, but behind
#if logic, and is ignorable for now.

o The harvest queue is pulled out into its own modules.

o Entropy harvesting is emproved, both by being made more conservative,
and by separating (a bit!) the sources. Available entropy crumbs are
marginally improved.

o Selection of sources is made clearer. With recent revelations,
this will receive more work in the weeks and months to come.

Submitted by: Arthur Mesh (partly) <arthurmesh@gmail.com>

The random_adapters.c is standard in the conf/files. Revert wrong
r254185.

Pointed out by: peter

Restore the ability to kldload random.ko, by linking in the newly
added random_adaptors.c.

Back out r253779 & r253786.

Decouple yarrow from random(4) device.

* Make Yarrow an optional kernel component -- enabled by "YARROW_RNG" option.
The files sha2.c, hash.c, randomdev_soft.c and yarrow.c comprise yarrow.

* random(4) device doesn't really depend on rijndael-*. Yarrow, however, does.

* Add random_adaptors.[ch] which is basically a store of random_adaptor's.
random_adaptor is basically an adapter that plugs in to random(4).
random_adaptor can only be plugged in to random(4) very early in bootup.
Unplugging random_adaptor from random(4) is not supported, and is probably a
bad idea anyway, due to potential loss of entropy pools.
We currently have 3 random_adaptors:
+ yarrow
+ rdrand (ivy.c)
+ nehemeiah

* Remove platform dependent logic from probe.c, and move it into
corresponding registration routines of each random_adaptor provider.
probe.c doesn't do anything other than picking a specific random_adaptor
from a list of registered ones.

* If the kernel doesn't have any random_adaptor adapters present then the
creation of /dev/random is postponed until next random_adaptor is kldload'ed.

* Fix randomdev_soft.c to refer to its own random_adaptor, instead of a
system wide one.

Submitted by: arthurmesh@gmail.com, obrien
Obtained from: Juniper Networks
Reviewed by: obrien

Add support for new Intel on-CPU Bull Mountain random number
generator, found on IvyBridge and supposedly later CPUs, accessible
with RDRAND instruction.

From the Intel whitepapers and articles about Bull Mountain, it seems
that we do not need to perform post-processing of RDRAND results, like
AES-encryption of the data with random IV and keys, which was done for
Padlock. Intel claims that sanitization is performed in hardware.

Make both Padlock and Bull Mountain random generators support code
covered by kernel config options, for the benefit of people who prefer
minimal kernels. Also add the tunables to disable hardware generator
even if detected.

Reviewed by: markm, secteam (simon)
Tested by: bapt, Michael Moll <kvedulv@kvedulv.de>
MFC after: 3 weeks

Enable hardware RNG for VIA Nano processors.

PR: kern/163974

Include nehemiah.c only on i386, as is done for the non-modules
build.

Reorganise the entropy device so that high-yield entropy sources
can more easily be used INSTEAD OF the hard-working Yarrow.
The only hardware source used at this point is the one inside
the VIA C3 Nehemiah (Stepping 3 and above) CPU. More sources will
be added in due course. Contributions welcome!

Upgrade the random device to use a "real" hash instead of building
one out of a block cipher. This has 2 advantages:
1) The code is _much_ simpler
2) We aren't committing our security to one algorithm (much as we
may think we trust AES).

While I'm here, make an explicit reseed do a slow reseed instead
of a fast; this is in line with what the original paper suggested.

Drop <bsd.man.mk> support from <bsd.kmod.mk>.

Not objected to by: -current

The /dev/random driver used Rijndael, not Blowfish, now.

Clean up Makefile, and remove the last vestiges of NOBLOCKRANDOM.

Use a consistent style and one much closer to the rest of /usr/src

Default the /dev/random loadable module to blocking-on-bootup,
but leave a commented-out macro to change this.

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.

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.

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.

Add entropy gathering code. This will work whether the module is
compiled in or loaded.

Better style(9) for the module build.

Build the entropy device (/dev/random) as a module. This may not
be a permanent rule, because this device may eventually be deemed
"effectively compulsory", and built by default directly into the
kernel. For the moment, however, this is useful for debugging and
development.

Reviewed by: dfr