File

util/uuid.lua @ 12115:94de6b7596cc

mod_tombstones: Remember deleted accounts #1307 Presence subscriptions are normally revoked on account deletion, which informs the contact. Sometimes this notification gets lost e.g. due to s2s problems. The accounts JID may also be present e.g. in MUC affiliations, chat group member lists, pubsub subscriptions or other systems. These may grant privileges which would fall to someone who creates the same account again, which this module is meant to prevent.
author Kim Alvefur <zash@zash.se>
date Thu, 23 Dec 2021 14:08:20 +0100
parent 7078:ec17115e3721
child 12355:a0ff5c438e9d
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-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

local random = require "util.random";
local random_bytes = random.bytes;
local hex = require "util.hex".to;
local m_ceil = math.ceil;

local function get_nibbles(n)
	return hex(random_bytes(m_ceil(n/2))):sub(1, n);
end

local function get_twobits()
	return ("%x"):format(random_bytes(1):byte() % 4 + 8);
end

local function generate()
	-- generate RFC 4122 complaint UUIDs (version 4 - random)
	return get_nibbles(8).."-"..get_nibbles(4).."-4"..get_nibbles(3).."-"..(get_twobits())..get_nibbles(3).."-"..get_nibbles(12);
end

return {
	get_nibbles=get_nibbles;
	generate = generate ;
	-- COMPAT
	seed = random.seed;
};