Pure Rust CSPRNG for the OxiCrypto stack.
Provides [OxiRng], a ChaCha20-based CSPRNG seeded from the OS
via getrandom.
Fork Safety
On Unix platforms, [OxiRng] tracks the process PID and automatically
reseeds after a fork() to prevent parent/child CSPRNG state sharing.
Thread-Local RNG
Use with_thread_rng (available with the std feature) for a convenient
per-thread RNG (lazily initialized, no explicit RNG management required).
ChaCha Variants
[OxiRng8] and [OxiRng12] provide ChaCha8 and ChaCha12-based CSPRNGs
for higher throughput when the full 20-round version is not required.
Entropy Health Check
[check_entropy] performs a basic OS-entropy smoke test (two independent
draws must be non-zero and differ). This is not a NIST SP 800-90B test.