On msvc14, int literal '-2147483648' is invalid, because '2147483648' is unsigned type and cant't apply minus operator to unsigned type.
To define the int literal correctly, use '-2147483647 - 1' formula that is also used to define INT_MIN in limits.h.
If InitBlockIndex fails, then it will segfault later. Same for the later
ActivateBestChain. BOOST_REQUIRE the result, so that an error will be
reported and the test case aborted.
Use of `sprintf` is seen as a red flag as many of its uses are insecure.
OpenBSD warns about it while compiling, and some modern platforms, e.g.
[cloudlibc from cloudabi](https://github.com/NuxiNL/cloudlibc) don't
even provide it anymore.
Although our uses of these functions are secure, it can't hurt to
replace them anyway. There are only 3 occurences left, all in the
tests.
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
Minimum boost version was bumped to 1.47.0 in #8920, which
means the configure step won't even pass with older boost.
This version has boost filesystem v3, which means the
(crappy) fallbacks for older versions can go.
Prior to this commit the err variable was not guaranteed to be set before
the check ...
BOOST_CHECK_MESSAGE(err != SCRIPT_ERR_OK, ScriptErrorString(err));
Fee estimation can just check its own mapMemPoolTxs to determine the same information. Note that now fee estimation for block processing must happen before those transactions are removed, but this shoudl be a speedup.
We were marking coins FRESH before being sure they were not overwriting dirty undo data. This condition was never reached in existing code because undo data was always flushed before UpdateCoins was called with new transactions, but could have been exposed in an otherwise safe refactor.
Clarify in the comments the assumptions made in ModifyNewCoins.
Add ability to undo transactions to UpdateCoins unit test.
Thanks to Russ Yanofsky for suggestion on how to make logic clearer and fixing up the ccoins_modify_new test cases.
Pieter Wuille