File

util/random.lua @ 13262:9a86e7cbdd79

mod_storage_internal: Fix fast trimming of archive with exactly one item This method would previously never delete the first (and only) item since it works out which item should become the first item after the trim operation, which doesn't make sense when all should be removed. This also works as an optimization for when all the last item should be trimmed, thus items should be removed.
author Kim Alvefur <zash@zash.se>
date Sun, 24 Sep 2023 13:41:54 +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";
};