-- Prosody IM

-- Copyright (C) 2008-2017 Matthew Wild

-- Copyright (C) 2008-2017 Waqas Hussain

-- Copyright (C) 2008-2017 Kim Alvefur

--

-- This project is MIT/X11 licensed. Please see the

-- COPYING file in the source package for more information.

--

local s_gsub = string.gsub;

local random_bytes = require "util.random".bytes;

local base64_encode = require "util.encodings".base64.encode;

local b64url = { ["+"] = "-", ["/"] = "_", ["="] = "" };

local function b64url_random(len)

	return (s_gsub(base64_encode(random_bytes(len)), "[+/=]", b64url));

end

return {

	short =  function () return b64url_random(6); end;

	medium = function () return b64url_random(12); end;

	long =   function () return b64url_random(24); end;

	custom = function (size)

		return function () return b64url_random(size); end;

	end;

}