55b2cb199c random: mark RandAddPeriodic and SeedPeriodic as noexcept (fanquake)
461e547877 doc: correct random.h docs after #17270 (fanquake)
Pull request description:
The usage of `MilliSleep()` in SeedPeriodic (previously SeedSleep) was
[removed](d61f2bb076) in #17270, meaning it, and its users can now be marked `noexcept`.
This also corrects the docs in random.h for some of the changes in #17270.
ACKs for top commit:
practicalswift:
ACK 55b2cb199c
laanwj:
ACK 55b2cb199c
sipa:
ACK 55b2cb199c
Tree-SHA512: 672d369796e7c4f9b4d98dc545e5454999fa1bef373871994a26041d6163c58909e2255e4f820d3ef011679aa3392754eb57477306a89f5fd3d57e2bd7f0811a
On the ::SLOW path we would use OpenSSL as an additional source of
random bytes. This commit removes that functionality. Note that this was
always only an additional source, and that we never checked the return
value
RAND_bytes(): https://www.openssl.org/docs/manmaster/man3/RAND_bytes.html
RAND_bytes() puts num cryptographically strong pseudo-random bytes into buf.
On the ::SLOW or ::SLEEP paths, we would feed our RNG output back into
OpenSSL using RAND_add. This commit removes that functionality.
RAND_add(): https://www.openssl.org/docs/manmaster/man3/RAND_add.html
RAND_add() mixes the num bytes at buf into the internal state of the
random generator. This function will not normally be needed, as
mentioned above. The randomness argument is an estimate of how much
randomness is contained in buf, in bytes, and should be a number
between zero and num.
* Instead of calling RandAddSeedSleep anytime the scheduler goes
idle, call its replacement (RandAddSeedPeriodic) just once per
minute. This has better guarantees of actually being run, and
helps limit how frequently the dynamic env data is gathered.
* Since this code runs once per minute regardless now, we no
longer need to keep track of the last time strengthening was
run; just do it always.
* Make strengthening time context dependent (100 ms at startup,
10 ms once per minute afterwards).
3cb9ce85d0 Document strenghtening (Pieter Wuille)
1d207bc46f Add hash strengthening to the RNG (Pieter Wuille)
Pull request description:
This patch improves the built-in RNG using hash strengthening.
At startup, and once every minute, 32 bytes of entropy are produced from the RNG, repeatedly hashed using SHA512 for 10ms, and then fed back into the RNG, together with high-precision timestamps obtained every 1000 iterations.
ACKs for commit 3cb9ce:
pstratem:
utACK 3cb9ce85d0
Tree-SHA512: 4fb6f61639b392697beb81c5f0903f79f10dd1087bed7f34de2abb5c22704a671e37b2d828ed141492491863efb1e7d1fa04408a1d32c9de2f2cc8ac406bbe57
1435fabc19 Use RdSeed when available, and reduce RdRand load (Pieter Wuille)
Pull request description:
This introduces support for autodetecting and using the RdSeed instruction on x86/x86_64 systems.
In addition:
* In SeedFast, only 64 bits of entropy are generated through RdRand (256 was relatively slow).
* In SeedStartup, 256 bits of entropy are generated, using RdSeed (preferably) or RdRand (otherwise).
Tree-SHA512: fb7d3e22e93e14592f4b07282aa79d7c3cc4e9debdd9978580b8d2562bbad345e289bf3f80de2c50c9b50b8bac2aa9b838f9f272f7f8d43f1efc0913aa8acce3
This introduces support for autodetecting and using the RdSeed instruction.
In addition:
* In SeedFast, only 64 bits of entropy are generated through RdRand (256 was relatively slow).
* In SeedStartup, 256 bits of entropy are generated, using RdSeed (preferably) or RdRand (otherwise).
It includes the following policy changes:
* All GetRand* functions seed the stack pointer and rdrand result
(in addition to the performance counter)
* The periodic entropy added by the idle scheduler now seeds stack pointer,
rdrand and perfmon data (once every 10 minutes) in addition to
just a sleep timing.
* The entropy added when calling GetStrongRandBytes no longer includes
the once-per-10-minutes perfmon data on windows (it is moved to the
idle scheduler instead, where latency matters less).
Other changes:
* OpenSSL is no longer seeded directly anywhere. Instead, any generated
randomness through our own RNG is fed back to OpenSSL (after an
additional hashing step to prevent leaking our RNG state).
* Seeding that was previously done directly in RandAddSeedSleep is now
moved to SeedSleep(), which is indirectly invoked through ProcRand
from RandAddSeedSleep.
* Seeding that was previously done directly in GetStrongRandBytes()
is now moved to SeedSlow(), which is indirectly invoked through
ProcRand from GetStrongRandBytes().
This guarantees that OpenSSL is initialized properly whenever randomness
is used, even when that randomness is invoked from global constructors.
Note that this patch uses Mutex directly, rather than CCriticalSection.
This is because the lock-detection code is not necessarily initialized
during global constructors.
Call sync.h primitives "locks" and "mutexes" instead of "blocks" and "waitable
critical sections" to match current coding conventions and c++11 standard
names.
This PR does not rename the "CCriticalSection" class (though this could be done
as a followup) because it is used everywhere and would swamp the other changes
in this PR. Plain mutexes should mostly be preferred instead of recursive
mutexes in new code anyway.
-BEGIN VERIFY SCRIPT-
set -x
set -e
ren() { git grep -l $1 | xargs sed -i s/$1/$2/; }
ren CCriticalBlock UniqueLock
ren CWaitableCriticalSection Mutex
ren CConditionVariable std::condition_variable
ren cs_GenesisWait g_genesis_wait_mutex
ren condvar_GenesisWait g_genesis_wait_cv
perl -0777 -pi -e 's/.*typedef.*condition_variable.*\n\n?//g' src/sync.h
-END VERIFY SCRIPT-
9c4dc597dd Use LOCK macros for non-recursive locks (Russell Yanofsky)
1382913e61 Make LOCK, LOCK2, TRY_LOCK work with CWaitableCriticalSection (Russell Yanofsky)
ba1f095aad MOVEONLY Move AnnotatedMixin declaration (Russell Yanofsky)
41b88e9337 Add unit test for DEBUG_LOCKORDER code (Russell Yanofsky)
Pull request description:
Make LOCK macros work with non-recursive mutexes, and use wherever possible for better deadlock detection.
Also add unit test for DEBUG_LOCKORDER code.
Tree-SHA512: 64ef209307f28ecd0813a283f15c6406138c6ffe7f6cbbd084161044db60e2c099a7d0d2edcd1c5e7770a115e9b931b486e86c9a777bdc96d2e8a9f4dc192942
