shithub: mc

ref: 37e813c6855bb09b73f4a7679ca2ce146152ee47
dir: /lib/crypto/entropy.myr/

use std

pkg crypto =
	const getentropy : (buf : byte[:] -> void)
;;

var randfd

const __init__ = {
	match std.open("/dev/urandom", std.Oread)
	| `std.Ok fd:	randfd = fd
	| `std.Err e:	randfd = std.try(std.open("/dev/random", std.Oread))
	;;
}

const getentropy = {buf
	var nread

	nread = 0
	while nread < buf.len
		match std.read(randfd, buf)
		| `std.Err e:	std.die(std.fmt("unable to read from randfd: {}\n", e))
		| `std.Ok 0:	std.die("could not get entropy from randfd: EOF\n")
		| `std.Ok n:	nread += n
		;;
	;;
}