view mod_auth_oauthbearer/mod_auth_oauthbearer.lua @ 5549:01a0b67a9afd

mod_http_oauth2: Add TODO about disabling password grant Per recommendation in draft-ietf-oauth-security-topics-23 it should at the very least be disabled by default. However since this is used by the Snikket web portal some care needs to be taken not to break this, unless it's already broken by other changes to this module.
author Kim Alvefur <zash@zash.se>
date Fri, 16 Jun 2023 00:06:53 +0200
parents d2bf9c8be3a3
children
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local host = module.host;
local log = module._log;
local new_sasl = require "util.sasl".new;
local base64 = require "util.encodings".base64.encode;

local provider = {};

local oauth_client_id = module:get_option_string("oauth_client_id",  "");
local oauth_client_secret = module:get_option_string("oauth_client_secret",  "");
local oauth_url = module:get_option_string("oauth_url",  "");

if oauth_client_id == "" then error("oauth_client_id required") end
if oauth_client_secret == "" then error("oauth_client_secret required") end
if oauth_url == "" then error("oauth_url required") end

-- globals required by socket.http
if rawget(_G, "PROXY") == nil then
	rawset(_G, "PROXY", false)
end
if rawget(_G, "base_parsed") == nil then
	rawset(_G, "base_parsed", false)
end

local function interp(s, tab)
	-- String interpolation, so that we can make the oauth_url configurable
	-- e.g. oauth_url = "https://api.github.com/applications/{{oauth_client_id}}/tokens/{{password}}";
	--
	-- See: http://lua-users.org/wiki/StringInterpolation
	return (s:gsub('(%b{})', function(w) return tab[w:sub(3, -3)] or w end))
end

function provider.test_password(username, password, realm)
	log("debug", "Testing signed OAuth2 for user %s at realm %s", username, realm);
	local https = require "ssl.https";
	local url = interp(oauth_url, {oauth_client_id = oauth_client_id, password = password});
	
	module:log("debug", "The URL is:  "..url);
	local _, code, headers, status = https.request{
		url = url,
		headers = {
			Authorization = "Basic "..base64(oauth_client_id..":"..oauth_client_secret);
		}
	};
	if type(code) == "number" and code >= 200 and code <= 299 then
		module:log("debug", "OAuth provider confirmed valid password");
		return true;
	else
		module:log("debug", "OAuth provider returned status code: "..code);
	end
	module:log("warn", "Auth failed. Invalid username/password or misconfiguration.");
	return nil;
end

function provider.users()
	return function()
		return nil;
	end
end

function provider.set_password(username, password)
	return nil, "Changing passwords not supported";
end

function provider.user_exists(username)
	return true;
end

function provider.create_user(username, password)
	return nil, "User creation not supported";
end

function provider.delete_user(username)
	return nil , "User deletion not supported";
end

function provider.get_sasl_handler()
	local supported_mechanisms = {};
	supported_mechanisms["OAUTHBEARER"] = true;
	return new_sasl(host, {
		oauthbearer = function(sasl, username, password, realm)
			return provider.test_password(username, password, realm), true;
		end,
        mechanisms = supported_mechanisms
	});
end

module:provides("auth", provider);