-- Prosody IM

-- Copyright (C) 2014 Matthew Wild

--

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

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

--

local usermanager = require "core.usermanager";

local new_sasl = require "util.sasl".new;

local nodeprep = require "util.encodings".stringprep.nodeprep;

local nameprep = require "util.encodings".stringprep.nameprep;

local md5 = require "util.hashes".md5;

local host = module.host;

local auth_filename = module:get_option_string("auth_ha1_file", "auth.txt");

local auth_data = {};

function reload_auth_data()

	local f, err = io.open(auth_filename);

	if not f then

		module:log("error", "Failed to read from auth file: %s", err);

		return;

	end

	auth_data = {};

	local line_number, imported_count, not_authorized_count = 0, 0, 0;

	for line in f:lines() do

		line_number = line_number + 1;

		local username, hash, realm, state = line:match("^([^:]+):(%x+):([^:]+):(.+)$");

		if not username then

			module:log("error", "Unable to parse line %d of auth file, skipping", line_number);

		else

			username, realm = nodeprep(username), nameprep(realm);

			if not username then

				module:log("error", "Invalid username on line %d of auth file, skipping", line_number);

			elseif not realm then

				module:log("error", "Invalid hostname/realm on line %d of auth file, skipping", line_number);

			elseif state ~= "authorized" then

				not_authorized_count = not_authorized_count + 1;

			elseif realm == host then

				auth_data[username] = hash;

				imported_count = imported_count + 1;

			end

		end

	end

	f:close();

	module:log("debug", "Loaded %d accounts from auth file (%d authorized)", imported_count, imported_count-not_authorized_count);

end

function module.load()

	reload_auth_data();

end

module:hook_global("config-reloaded", reload_auth_data);

-- define auth provider

local provider = {};

function provider.test_password(username, password)

	module:log("debug", "test password for user %s at host %s, %s", username, host, password);

	local test_hash = md5(username..":"..host..":"..password, true);

	if test_hash == auth_data[username] then

		return true;

	else

		return nil, "Auth failed. Invalid username or password.";

	end

end

function provider.set_password(username, password)

	return nil, "Changing passwords not supported";

end

function provider.user_exists(username)

	if not auth_data[username] then

		module:log("debug", "account not found for username '%s' at host '%s'", username, host);

		return nil, "Auth failed. Invalid username";

	end

	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()

	return new_sasl(host, {

		plain_test = function(sasl, username, password, realm)

			return usermanager.test_password(username, realm, password), true;

		end

	});

end

module:provides("auth", provider);