r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.
Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT
Reviewed by: cem
Approved by: csprng, kib (mentor, blanket)
Differential Revision: https://reviews.freebsd.org/D23841
The number is public and has no "entropy," but should be integrated quickly
on VM rewind events to avoid duplicate sequences.
Approved by: csprng(markm)
Differential Revision: https://reviews.freebsd.org/D22946
Allow loadable modules that provide random entropy source(s) to safely
unload. Prior to this change, no driver could ensure that their
random_source structure was not being used by random_harvestq.c for any
period of time after invoking random_source_deregister().
This change converts the source_list LIST to a ConcurrencyKit CK_LIST and
uses an epoch(9) to protect typical read accesses of the list. The existing
HARVEST_LOCK spin mutex is used to safely add and remove list entries.
random_source_deregister() uses epoch_wait() to ensure no concurrent
source_list readers are accessing a random_source before freeing the list
item and returning to the caller.
Callers can safely unload immediately after random_source_deregister()
returns.
Reviewed by: markj
Approved by: csprng(markm)
Discussed with: jhb
Differential Revision: https://reviews.freebsd.org/D22489
Simplify RANDOM_LOADABLE by removing the ability to unload a LOADABLE
random(4) implementation. This allows one-time random module selection
at boot, by loader(8). Swapping modules on the fly doesn't seem
especially useful.
This removes the need to hold a lock over the sleepable module calls
read_random and read_random_uio.
init/deinit have been pulled out of random_algorithm entirely. Algorithms
can run their own sysinits to initialize; deinit is removed entirely, as
algorithms can not be unloaded. Algorithms should initialize at
SI_SUB_RANDOM:SI_ORDER_SECOND. In LOADABLE systems, algorithms install
a pointer to their local random_algorithm context in p_random_alg_context at
that time.
Go ahead and const'ify random_algorithm objects; there is no need to mutate
them at runtime.
LOADABLE kernel NULL checks are removed from random_harvestq by ordering
random_harvestq initialization at SI_SUB_RANDOM:SI_ORDER_THIRD, after
algorithm init. Prior to random_harvestq init, hc_harvest_mask is zero and
no events are forwarded to algorithms; after random_harvestq init, the
relevant pointers will already have been installed.
Remove the bulk of random_infra shim wrappers and instead expose the bare
function pointers in sys/random.h. In LOADABLE systems, read_random(9) et
al are just thin shim macros around invoking the associated function
pointer. We do not provide a registration system but instead expect
LOADABLE modules to register themselves at SI_SUB_RANDOM:SI_ORDER_SECOND.
An example is provided in randomdev.c, as used in the random_fortuna.ko
module.
Approved by: csprng(markm)
Discussed with: gordon
Differential Revision: https://reviews.freebsd.org/D22512
The internal datastructures do not need to be visible outside of
random_harvestq, and this helps ensure they are not misused.
No functional change.
Approved by: csprng(delphij, markm)
Differential Revision: https://reviews.freebsd.org/D22485
There's no need to dynamically populate them; the SYSCTL_ macros take care
of load/unload appropriately already (and random_harvestq is 'standard' and
cannot be unloaded anyway).
Approved by: csprng(delphij, markm)
Differential Revision: https://reviews.freebsd.org/D22484
Break random_harvestq_prime up into some logical subroutines. The goal
is that it becomes easier to add other early entropy sources.
While here, drop pre-12.0 compatibility logic. loader default configuration
should preload the file as expeced since 12.0.
Approved by: csprng(delphij, markm)
Differential Revision: https://reviews.freebsd.org/D22482
Move fast entropy source registration to the earlier
SI_SUB_RANDOM:SI_ORDER_FOURTH and move random_harvestq_prime after that.
Relocate the registration routines out of the much later randomdev module
and into random_harvestq.
This is necessary for the fast random sources to actually register before we
perform random_harvestq_prime() early in the kernel boot.
No functional change.
Reviewed by: delphij, markjm
Approved by: secteam(delphij)
Differential Revision: https://reviews.freebsd.org/D21308
Pull the responsibility for zeroing events, which is general to any
conceivable implementation of a random device algorithm, out of the
algorithm-specific Fortuna code and into the callers. Most callers
indirect through random_fortuna_process_event(), so add the logic there.
Most callers already explicitly bzeroed the events they provided, so the
logic in Fortuna was mostly redundant.
Add one missing bzero in randomdev_accumulate(). Also, remove a redundant
bzero in the same function -- randomdev_hash_finish() is obliged to bzero
the hash state.
Reviewed by: delphij
Approved by: secteam(delphij)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20318
Mjg@ reports that RDSEED (r347239) causes a lot of logspam from this printf,
and I don't feel that it is especially useful (even ratelimited). There are
many other quality/quantity checks we're not performing on entropy sources;
lack of high frequency availability does not disqualify a good entropy
source.
There is some discussion in the linked Differential about what logging might
be appropriate and/or polling policy for slower TRNG sources. Please feel
free to chime in if you have opinions.
Reported by: mjg
Reviewed by: markm, delphij
Approved by: secteam(delphij)
X-MFC-With: r347239
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D20195
read_random() is/was used, mostly without error checking, in a lot of
very sensitive places in the kernel -- including seeding the widely used
arc4random(9).
Most uses, especially arc4random(9), should block until the device is seeded
rather than proceeding with a bogus or empty seed. I did not spy any
obvious kernel consumers where blocking would be inappropriate (in the
sense that lack of entropy would be ok -- I did not investigate locking
angle thoroughly). In many instances, arc4random_buf(9) or that family
of APIs would be more appropriate anyway; that work was done in r345865.
A minor cleanup was made to the implementation of the READ_RANDOM function:
instead of using a variable-length array on the stack to temporarily store
all full random blocks sufficient to satisfy the requested 'len', only store
a single block on the stack. This has some benefit in terms of reducing
stack usage, reducing memcpy overhead and reducing devrandom output leakage
via the stack. Additionally, the stack block is now safely zeroed if it was
used.
One caveat of this change is that the kern.arandom sysctl no longer returns
zero bytes immediately if the random device is not seeded. This means that
FreeBSD-specific userspace applications which attempted to handle an
unseeded random device may be broken by this change. If such behavior is
needed, it can be replaced by the more portable getrandom(2) GRND_NONBLOCK
option.
On any typical FreeBSD system, entropy is persisted on read/write media and
used to seed the random device very early in boot, and blocking is never a
problem.
This change primarily impacts the behavior of /dev/random on embedded
systems with read-only media that do not configure "nodevice random". We
toggle the default from 'charge on blindly with no entropy' to 'block
indefinitely.' This default is safer, but may cause frustration. Embedded
system designers using FreeBSD have several options. The most obvious is to
plan to have a small writable NVRAM or NAND to persist entropy, like larger
systems. Early entropy can be fed from any loader, or by writing directly
to /dev/random during boot. Some embedded SoCs now provide a fast hardware
entropy source; this would also work for quickly seeding Fortuna. A 3rd
option would be creating an embedded-specific, more simplistic random
module, like that designed by DJB in [1] (this design still requires a small
rewritable media for forward secrecy). Finally, the least preferred option
might be "nodevice random", although I plan to remove this in a subsequent
revision.
To help developers emulate the behavior of these embedded systems on
ordinary workstations, the tunable kern.random.block_seeded_status was
added. When set to 1, it blocks the random device.
I attempted to document this change in random.4 and random.9 and ran into a
bunch of out-of-date or irrelevant or inaccurate content and ended up
rototilling those documents more than I intended to. Sorry. I think
they're in a better state now.
PR: 230875
Reviewed by: delphij, markm (earlier version)
Approved by: secteam(delphij), devrandom(markm)
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D19744
TPM has a built-in RNG, with its own entropy source.
The driver was extended to harvest 16 random bytes from TPM every 10 seconds.
A new build option "TPM_HARVEST" was introduced - for now, however, it
is not enabled by default in the GENERIC config.
Submitted by: Kornel Duleba <mindal@semihalf.com>
Reviewed by: markm, delphij
Approved by: secteam
Obtained from: Semihalf
Sponsored by: Stormshield
Differential Revision: https://reviews.freebsd.org/D19620
r287023 and r334450 added build option mechanisms to permanently disable
spammy and/or low quality entropy sources.
Follow-up those changes by updating the 'enabled' sources mask to match.
When sources are compile-time disabled, represent them as disabled in the
source mask, and prevent users from modifying that, like pure sources.
(Modifying the mask bit would have no effect, but users might think it did
if it was not prevented.)
Mostly a cosmetic change.
Reviewed by: markm
Approved by: secteam (gordon)
X-MFC-With: 334450
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D17252
The convention for updating hc_destination[] is to index with a
random_entropy_source. Zero happens to match RANDOM_CACHED, which is
correct for this source (early random data). Spell the zero value as the
enum name instead of the magic constant.
No functional change.
Reviewed by: delphij, markm
Approved by: secteam (delphij)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D16983
given in random(4).
This includes updating of the relevant man pages, and no-longer-used
harvesting parameters.
Ensure that the pseudo-unit-test still does something useful, now also
with the "other" algorithm instead of Yarrow.
PR: 230870
Reviewed by: cem
Approved by: so(delphij,gtetlow)
Approved by: re(marius)
Differential Revision: https://reviews.freebsd.org/D16898
for security, and the excess just slows things down badly.
PR: 230808
Submitted by: rwmaillists@googlemail.com, but tweeked by me
Reported by: Danilo Egea Gondolfo <danilo@FreeBSD.org>
Reviewed by: cem,delphij
Approved by: re(rgrimes)
Approved by: so(delphij)
MFC after: 1 Month
Differential Revision: https://reviews.freebsd.org/D16873
Summary:
PowerISA 3.0 adds a 'darn' instruction to "deliver a random number". This
driver was modeled after (rather, copied and gutted of) the Ivy Bridge
rdrand driver.
This uses the "Conditional Random Number" behavior to remove input bias.
From the ISA reference the 'darn' instruction, and the random number
generator backing it, conforms to the NIST SP800-90B and SP800-90C
standards, compliant to the extent possible at the time the hardware was
designed, and guarantees a minimum 0.5 bits of entropy per bit returned.
Reviewed By: markm, secteam (delphij)
Approved by: secteam (delphij)
Differential Revision: https://reviews.freebsd.org/D16552
- move harvest mask check inline
- move harvest mask to frequently_read out of actively
modified cache line
- disable ether_input collection and describe its limitations
in NOTES
Typically entropy collection in ether_input was stirring zero
in to the entropy pool while at the same time greatly reducing
max pps. This indicates that perhaps we should more closely
scrutinize how much entropy we're getting from a given source
as well as what our actual entropy collection needs are for
seeding Yarrow.
Reviewed by: cem, gallatin, delphij
Approved by: secteam
Differential Revision: https://reviews.freebsd.org/D15526
The implementation will follow (D12723). For now, get the changes to
commit-protected files out of the way.
Approved by: secteam (gordon)
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D13925
At initialization, hc_source_mask only includes non-Pure sources.
The patch changes source registration to enable the registered source in the
hc_source_mask bitmask. This mask governs which sources are harvested.
This patch also disallows userspace from disabling such sources.
PR: 222807
Submitted by: W. Dean Freeman <badfilemagic AT gmail.com>
Reviewed by: jmg (earlier version), delphij
Approved by: secteam (delphij)
Obtained from: HBSD 0054e3e170e083811acc9f3b637f8be8a86c03e7
Security: yes
Differential Revision: https://reviews.freebsd.org/D12611
numbers with Chacha20. Keep the API, though, as that is what the
other *BSD's have done.
Use the boot-time entropy stash (if present) to bootstrap the
in-kernel entropy source.
Reviewed by: delphij,rwatson
Approved by: so(delphij)
MFC after: 2 months
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D10048
This is a no-op currently, but in kernels with earlier AP startup, the
random kthread was trying to use timeouts with sleeps before timers are
working. Wait until SI_SUB_KICK_SCHEDULER to start the random kproc.
Reviewed by: delphij, imp, markm
Approved by: so
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D5712
'rdrand' instruction may occasionally not return random numbers, in
spite of looping attempts to do so. The reusult is a KASSERT/panic.
Reluctantly accept this state-of-affairs, but make a noise about it.
if this 'noise' spams the console, it may be time to discontinue
using that source.
This is written in a general way to account for /any/ source that
might not supply random numbers when required.
Submitted by: jkh (report and slightly different fix)
Approved by: so (/dev/random blanket)
Provide and document the RANDOM_ENABLE_UMA option.
Change RANDOM_FAST to RANDOM_UMA to clarify the harvesting.
Remove RANDOM_DEBUG option, replace with SDT probes. These will be of
use to folks measuring the harvesting effect when deciding whether to
use RANDOM_ENABLE_UMA.
Requested by: scottl and others.
Approved by: so (/dev/random blanket)
Differential Revision: https://reviews.freebsd.org/D3197
if desired.
Retire randomdev_none.c and introduce random_infra.c for resident
infrastructure. Completely stub out random(4) calls in the "without
DEV_RANDOM" case.
Add RANDOM_LOADABLE option to allow loadable Yarrow/Fortuna/LocallyWritten
algorithm. Add a skeleton "other" algorithm framework for folks
to add their own processing code. NIST, anyone?
Retire the RANDOM_DUMMY option.
Build modules for Yarrow, Fortuna and "other".
Use atomics for the live entropy rate-tracking.
Convert ints to bools for the 'seeded' logic.
Move _write() function from the algorithm-specific areas to randomdev.c
Get rid of reseed() function - it is unused.
Tidy up the opt_*.h includes.
Update documentation for random(4) modules.
Fix test program (reviewers, please leave this).
Differential Revision: https://reviews.freebsd.org/D3354
Reviewed by: wblock,delphij,jmg,bjk
Approved by: so (/dev/random blanket)
- Tweek man page.
- Remove all mention of RANDOM_FORTUNA. If the system owner wants YARROW or DUMMY, they ask for it, otherwise they get FORTUNA.
- Tidy up headers a bit.
- Tidy up declarations a bit.
- Make static in a couple of places where needed.
- Move Yarrow/Fortuna SYSINIT/SYSUNINIT to randomdev.c, moving us towards a single file where the algorithm context is used.
- Get rid of random_*_process_buffer() functions. They were only used in one place each, and are better subsumed into those places.
- Remove *_post_read() functions as they are stubs everywhere.
- Assert against buffer size illegalities.
- Clean up some silly code in the randomdev_read() routine.
- Make the harvesting more consistent.
- Make some requested argument name changes.
- Tidy up and clarify a few comments.
- Make some requested comment changes.
- Make some requested macro changes.
* NOTE: the thing calling itself a 'unit test' is not yet a proper
unit test, but it helps me ensure things work. It may be a proper
unit test at some time in the future, but for now please don't make
any assumptions or hold any expectations.
Differential Revision: https://reviews.freebsd.org/D2025
Approved by: so (/dev/random blanket)
* GENERAL
- Update copyright.
- Make kernel options for RANDOM_YARROW and RANDOM_DUMMY. Set
neither to ON, which means we want Fortuna
- If there is no 'device random' in the kernel, there will be NO
random(4) device in the kernel, and the KERN_ARND sysctl will
return nothing. With RANDOM_DUMMY there will be a random(4) that
always blocks.
- Repair kern.arandom (KERN_ARND sysctl). The old version went
through arc4random(9) and was a bit weird.
- Adjust arc4random stirring a bit - the existing code looks a little
suspect.
- Fix the nasty pre- and post-read overloading by providing explictit
functions to do these tasks.
- Redo read_random(9) so as to duplicate random(4)'s read internals.
This makes it a first-class citizen rather than a hack.
- Move stuff out of locked regions when it does not need to be
there.
- Trim RANDOM_DEBUG printfs. Some are excess to requirement, some
behind boot verbose.
- Use SYSINIT to sequence the startup.
- Fix init/deinit sysctl stuff.
- Make relevant sysctls also tunables.
- Add different harvesting "styles" to allow for different requirements
(direct, queue, fast).
- Add harvesting of FFS atime events. This needs to be checked for
weighing down the FS code.
- Add harvesting of slab allocator events. This needs to be checked for
weighing down the allocator code.
- Fix the random(9) manpage.
- Loadable modules are not present for now. These will be re-engineered
when the dust settles.
- Use macros for locks.
- Fix comments.
* src/share/man/...
- Update the man pages.
* src/etc/...
- The startup/shutdown work is done in D2924.
* src/UPDATING
- Add UPDATING announcement.
* src/sys/dev/random/build.sh
- Add copyright.
- Add libz for unit tests.
* src/sys/dev/random/dummy.c
- Remove; no longer needed. Functionality incorporated into randomdev.*.
* live_entropy_sources.c live_entropy_sources.h
- Remove; content moved.
- move content to randomdev.[ch] and optimise.
* src/sys/dev/random/random_adaptors.c src/sys/dev/random/random_adaptors.h
- Remove; plugability is no longer used. Compile-time algorithm
selection is the way to go.
* src/sys/dev/random/random_harvestq.c src/sys/dev/random/random_harvestq.h
- Add early (re)boot-time randomness caching.
* src/sys/dev/random/randomdev_soft.c src/sys/dev/random/randomdev_soft.h
- Remove; no longer needed.
* src/sys/dev/random/uint128.h
- Provide a fake uint128_t; if a real one ever arrived, we can use
that instead. All that is needed here is N=0, N++, N==0, and some
localised trickery is used to manufacture a 128-bit 0ULLL.
* src/sys/dev/random/unit_test.c src/sys/dev/random/unit_test.h
- Improve unit tests; previously the testing human needed clairvoyance;
now the test will do a basic check of compressibility. Clairvoyant
talent is still a good idea.
- This is still a long way off a proper unit test.
* src/sys/dev/random/fortuna.c src/sys/dev/random/fortuna.h
- Improve messy union to just uint128_t.
- Remove unneeded 'static struct fortuna_start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])
* src/sys/dev/random/yarrow.c src/sys/dev/random/yarrow.h
- Improve messy union to just uint128_t.
- Remove unneeded 'staic struct start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])
- Fix some magic numbers elsewhere used as FAST and SLOW.
Differential Revision: https://reviews.freebsd.org/D2025
Reviewed by: vsevolod,delphij,rwatson,trasz,jmg
Approved by: so (delphij)
This code has had an extensive rewrite and a good series of reviews, both by the author and other parties. This means a lot of code has been simplified. Pluggable structures for high-rate entropy generators are available, and it is most definitely not the case that /dev/random can be driven by only a hardware souce any more. This has been designed out of the device. Hardware sources are stirred into the CSPRNG (Yarrow, Fortuna) like any other entropy source. Pluggable modules may be written by third parties for additional sources.
The harvesting structures and consequently the locking have been simplified. Entropy harvesting is done in a more general way (the documentation for this will follow). There is some GREAT entropy to be had in the UMA allocator, but it is disabled for now as messing with that is likely to annoy many people.
The venerable (but effective) Yarrow algorithm, which is no longer supported by its authors now has an alternative, Fortuna. For now, Yarrow is retained as the default algorithm, but this may be changed using a kernel option. It is intended to make Fortuna the default algorithm for 11.0. Interested parties are encouraged to read ISBN 978-0-470-47424-2 "Cryptography Engineering" By Ferguson, Schneier and Kohno for Fortuna's gory details. Heck, read it anyway.
Many thanks to Arthur Mesh who did early grunt work, and who got caught in the crossfire rather more than he deserved to.
My thanks also to folks who helped me thresh this out on whiteboards and in the odd "Hallway track", or otherwise.
My Nomex pants are on. Let the feedback commence!
Reviewed by: trasz,des(partial),imp(partial?),rwatson(partial?)
Approved by: so(des)
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.
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
r256239 | des | 2013-10-09 21:12:59 +0100 (Wed, 09 Oct 2013) | 2 lines
Define RANDOM_PURE_RNDTEST for rndtest(4).
------------------------------------------------------------------------
r256204 | des | 2013-10-09 18:51:38 +0100 (Wed, 09 Oct 2013) | 2 lines
staticize struct random_hardware_source
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
r256184 | des | 2013-10-09 10:13:12 +0100 (Wed, 09 Oct 2013) | 2 lines
Re-add /dev/urandom for compatibility purposes.
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
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)
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
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>
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
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)
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
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>
------------------------------------------------------------------------
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>
------------------------------------------------------------------------
r254934 | markm | 2013-08-26 20:07:03 +0100 (Mon, 26 Aug 2013) | 2 lines
Remove the short-lived namei experiment.
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
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)
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.
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.
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.
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.
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.
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)
