File

util/random.lua @ 13126:d043834f15d2

mod_http: Use RFC 7239 Forwarded header to find original client IP Prefer over X-Forwarded-* since it has an actual specification. Main practical difference is that Forwarded may carry more properties than only the IP address since it is a structured header. Since we parse it into an array, it is easier to do the logical thing and iterate backwards trough proxies until an untrusted one is encountered. Compare the handling of X-Forwarded-For. The 'secure' field now accounts for the full chain of proxies, which must be secure all the way to be considered secure.
author Kim Alvefur <zash@zash.se>
date Sat, 03 Jun 2023 17:10:04 +0200
parent 12975:d10957394a3c
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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, "prosody.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";
};