File

util/random.lua @ 11962:9a70a543c727

util.async: Add next-tick configuration Running woken runners in the next iteration of the event loop prevents unexpected recursion, unexpected tracebacks, and is generally more predictable. The pattern is borrowed from util.promise, where we're now doing the same.
author Matthew Wild <mwild1@gmail.com>
date Mon, 29 Nov 2021 14:14:30 +0000
parent 10016:af8c514e5cf7
child 12446:e54b8a5e35ad
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-- Prosody IM
-- Copyright (C) 2008-2014 Matthew Wild
-- Copyright (C) 2008-2014 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

local ok, crand = pcall(require, "util.crand");
if ok then return crand; end

local urandom, urandom_err = io.open("/dev/urandom", "r");

local function bytes(n)
	local data, err = urandom:read(n);
	if not data then
		if err then
			error("Unable to retrieve data from secure random number generator (/dev/urandom): "..tostring(err));
		else
			error("Secure random number generator (/dev/urandom) returned an end-of-file condition");
		end
	end
	return data;
end

if not urandom then
	function bytes()
		error("Unable to obtain a secure random number generator, please see https://prosody.im/doc/random ("..urandom_err..")");
	end
end

return {
	bytes = bytes;
	_source = "/dev/urandom";
};