File

core.certmanager: Move EECDH ciphers before EDH in default cipherstring The original intent of having kEDH before kEECDH was that if a `dhparam` file was specified, this would be interpreted as a preference by the admin for old and well-tested Diffie-Hellman key agreement over newer elliptic curve ones. Otherwise the faster elliptic curve ciphersuites would be preferred. This didn't really work as intended since this affects the ClientHello on outgoing s2s connections, leading to some servers using poorly configured kEDH. With Debian shipping OpenSSL settings that enforce a higher security level, this caused interoperability problems with servers that use DH params smaller than 2048 bits. E.g. jabber.org at the time of this writing has 1024 bit DH params. MattJ says > Curves have won, and OpenSSL is less weird about them now

-- 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;
}