util/random.lua
author Matthew Wild <mwild1@gmail.com>
Mon, 31 Oct 2022 14:32:02 +0000
branch0.12
changeset 12794 24b55f0e2db9
parent 12450 e54b8a5e35ad
child 12979 d10957394a3c
permissions -rw-r--r--
mod_http: Allow disabling CORS in the http_cors_override option and by default Fixes #1779. Due to an oversight in the logic, if the user set 'enabled' to false in an override, it would disable the item's requested CORS settings, but still apply Prosody's default CORS policy. This change ensures that 'enabled = false' will now disable CORS entirely for the requested item. Due to the new structure of the code, it was necessary to have a flag to say whether CORS is to be applied at all. Rather than hard-coding 'true' here, I chose to add a new option: 'http_default_cors_enabled'. This is a boolean that allows the operator to disable Prosody's default CORS policy entirely (the one that is used when a module or config does not override it). This makes it easier to disable CORS and then selectively enable it only on services you want it on.

-- 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 and pcall(crand.bytes, 1) 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";
};