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.
Send payments during the test from a different node than the node generating
keys to be imported, so the spending node doesn't create transactions that
inadvertently involve (spend funds from) the imported keys.
Fixes#9826
This commit fixes the module-level docstrings for the tests and helper
modules in qa. Many of these tests were uncommented previously - this
commit ensures that every test case has at least a minimum level of
commenting.
- Change initializeResult(int) to initializeResult(bool) to avoid
implicit type conversion.
- Use EXIT_FAILURE and EXIT_SUCCESS instead of magic numbers.
- Remove the argument from shutdownResult(int); it was called with a
constant argument.
Warnings introduced by commit e2e2f4c "Return errors from importmulti if
complete rescans are not successful" and reported by Pavel Janík
<Pavel@Janik.cz> in https://github.com/bitcoin/bitcoin/pull/9773 and
https://github.com/bitcoin/bitcoin/pull/9827
wallet/test/wallet_tests.cpp: In member function ‘void wallet_tests::rescan::test_method()’:
wallet/test/wallet_tests.cpp:377:17: warning: declaration of ‘wallet’ shadows a global declaration [-Wshadow]
CWallet wallet;
An effort to reduce the size of AppInitMain().
The removed code upgrades the location of the block files when
upgrading to 0.8. 0.8 seems to be the oldest version still in use.
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
