cipher.chacha20

The module cipher.chacha20 of lua-cipher provides the stream cipher
ChaCha20 (RFC 8439, also with 64 bit nonces and as XChaCha20), the
authenticated encryption ChaCha20-Poly1305 of RFC 8439 and
XChaCha20-Poly1305, and the one-time authenticator Poly1305, in one call
or as a stream. Own self-contained C code without table lookups, no
external library. Data may be Lua strings or carray objects, read
without copying; the output can be written directly into a carray.