File

core.certmanager: Move EECDH ciphers before EDH in default cipherstring (fixes #1513) Backport of 94e341dee51c 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

local s_char = string.char;
local s_format = string.format;
local s_gsub = string.gsub;
local s_lower = string.lower;

local char_to_hex = {};
local hex_to_char = {};

do
	local char, hex;
	for i = 0,255 do
		char, hex = s_char(i), s_format("%02x", i);
		char_to_hex[char] = hex;
		hex_to_char[hex] = char;
	end
end

local function to(s)
	return (s_gsub(s, ".", char_to_hex));
end

local function from(s)
	return (s_gsub(s_lower(s), "%X*(%x%x)%X*", hex_to_char));
end

return { to = to, from = from }