kvazar/kevacoin - kevacoin - Purple I2P team Git service

Author	SHA1	Message	Date
Pieter Wuille	4fd2d2fc97	Add a FastRandomContext::randrange and use it	8 years ago
Pieter Wuille	16329224e7	Switch FastRandomContext to ChaCha20	8 years ago
Wladimir J. van der Laan	7cad849299	sanity: Move OS random to sanity check function 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.	8 years ago
Wladimir J. van der Laan	224e6eb089	util: Specific GetOSRandom for Linux/FreeBSD/OpenBSD 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	8 years ago