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
b82c55a Add attribute [[noreturn]] (C++11) to functions that will not return (practicalswift)
Pull request description:
Add attribute `[[noreturn]]` (C++11) to functions that will not return.
Rationale:
* Reduce the number of false positives/false negatives from static analyzers with regards to things such as unused or unreachable code
* Potentially enable additional compiler optimizations
Tree-SHA512: 899683fe8b2fcf19bd334352271d368b46b805be9d426aac1808335fd95732d6d7078d3296951b9879196f3f6e3ec0fdb7695d0afdc3fbe4dd78a2ca70e91ff7
90d4d89 scripted-diff: Use the C++11 keyword nullptr to denote the pointer literal instead of the macro NULL (practicalswift)
Pull request description:
Since C++11 the macro `NULL` may be:
* an integer literal with value zero, or
* a prvalue of type `std::nullptr_t`
By using the C++11 keyword `nullptr` we are guaranteed a prvalue of type `std::nullptr_t`.
For a more thorough discussion, see "A name for the null pointer: nullptr" (Sutter &
Stroustrup), http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2431.pdf
With this patch applied there are no `NULL` macro usages left in the repo:
```
$ git grep NULL -- "*.cpp" "*.h" | egrep -v '(/univalue/|/secp256k1/|/leveldb/|_NULL|NULLDUMMY|torcontrol.*NULL|NULL cert)' | wc -l
0
```
The road towards `nullptr` (C++11) is split into two PRs:
* `NULL` → `nullptr` is handled in PR #10483 (scripted, this PR)
* `0` → `nullptr` is handled in PR #10645 (manual)
Tree-SHA512: 3c395d66f2ad724a8e6fed74b93634de8bfc0c0eafac94e64e5194c939499fefd6e68f047de3083ad0b4eff37df9a8a3a76349aa17d55eabbd8e0412f140a297
rbx needs to be stashed in a 64bit register on 64bit platforms. With this crash
in particular, it was holding a stack canary which was not properly restored
after the cpuid.
Split out the x86+PIC case so that x86_64 doesn't have to worry about it.
cb24c85 Use rdrand as entropy source on supported platforms (Pieter Wuille)
Tree-SHA512: c42eaa01a14e6bc097c70b6bf8540d61854c2f76cb32be69c2a3c411a126f7b4bf4a4486e4493c4cc367cc689319abde0d4adb799d29a54fd3e81767ce0766fc
97477c5 Maintain state across GetStrongRandBytes calls (Pieter Wuille)
Tree-SHA512: 77e9b1f3c6eeb0c2a3e0c64358150767222ff0b7120ccd5f4ae0276cea0e4fa275c1b757e3f20be07dc0b4ef07f70ab0b70112080c8d3d0cb6ed703db8a59168
This changes the logging categories to boolean flags instead of strings.
This simplifies the acceptance testing by avoiding accessing a scoped
static thread local pointer to a thread local set of strings. It
eliminates the only use of boost::thread_specific_ptr outside of
lockorder debugging.
This change allows log entries to be directed to multiple categories
and makes it easy to change the logging flags at runtime (e.g. via
an RPC, though that isn't done by this commit.)
It also eliminates the fDebug global.
Configuration of unknown logging categories now produces a warning.
If the code was compiled with newer (>=3.17) kernel headers but executed
on a system without the system call, every use of random would crash the
program. Add a fallback for that case.
Move the OS random test to a sanity check function that is called every
time bitcoind is initialized.
Keep `src/test/random_tests.cpp` for the case that later random tests
are added, and keep a rudimentary test that just calls the sanity check.
These are available in sandboxes without access to files or
devices. Also [they are safer and more straightforward](https://en.wikipedia.org/wiki/Entropy-supplying_system_calls)
to use than `/dev/urandom` as reading from a file has quite a few edge
cases:
- Linux: `getrandom(buf, buflen, 0)`. [getrandom(2)](http://man7.org/linux/man-pages/man2/getrandom.2.html)
was introduced in version 3.17 of the Linux kernel.
- OpenBSD: `getentropy(buf, buflen)`. The [getentropy(2)](http://man.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man2/getentropy.2)
function appeared in OpenBSD 5.6.
- FreeBSD and NetBSD: `sysctl(KERN_ARND)`. Not sure when this was added
but it has existed for quite a while.
Alternatives:
- Linux has sysctl `CTL_KERN` / `KERN_RANDOM` / `RANDOM_UUID`
which gives 16 bytes of randomness. This may be available
on older kernels, however [sysctl is deprecated on Linux](https://lwn.net/Articles/605392/)
and even removed in some distros so we shouldn't use it.
Add tests for `GetOSRand()`:
- Test that no error happens (otherwise `RandFailure()` which aborts)
- Test that all 32 bytes are overwritten (initialize with zeros, try multiple times)
Discussion:
- When to use these? Currently they are always used when available.
Another option would be to use them only when `/dev/urandom` is not
available. But this would mean these code paths receive less testing,
and I'm not sure there is any reason to prefer `/dev/urandom`.
Closes: #9676
There are only a few uses of `insecure_random` outside the tests.
This PR replaces uses of insecure_random (and its accompanying global
state) in the core code with an FastRandomContext that is automatically
seeded on creation.
This is meant to be used for inner loops. The FastRandomContext
can be in the outer scope, or the class itself, then rand32() is used
inside the loop. Useful e.g. for pushing addresses in CNode or the fee
rounding, or randomization for coin selection.
As a context is created per purpose, thus it gets rid of
cross-thread unprotected shared usage of a single set of globals, this
should also get rid of the potential race conditions.
- I'd say TxMempool::check is not called enough to warrant using a special
fast random context, this is switched to GetRand() (open for
discussion...)
- The use of `insecure_rand` in ConnectThroughProxy has been replaced by
an atomic integer counter. The only goal here is to have a different
credentials pair for each connection to go on a different Tor circuit,
it does not need to be random nor unpredictable.
- To avoid having a FastRandomContext on every CNode, the context is
passed into PushAddress as appropriate.
There remains an insecure_random for test usage in `test_random.h`.
