--
-- Prosody IM
-- Copyright (C) 2010 Waqas Hussain
-- Copyright (C) 2010 Jeff Mitchell
-- Copyright (C) 2013 Mikael Nordfeldth
-- Copyright (C) 2013 Matthew Wild, finally came to fix it all
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--
local lpty = assert(require "lpty", "mod_auth_external requires lpty: https://modules.prosody.im/mod_auth_external.html#installation");
local usermanager = require "core.usermanager";
local new_sasl = require "util.sasl".new;
local server = require "net.server";
local have_async, async = pcall(require, "util.async");
local log = module._log;
local host = module.host;
local script_type = module:get_option_string("external_auth_protocol", "generic");
local command = module:get_option_string("external_auth_command", "");
local read_timeout = module:get_option_number("external_auth_timeout", 5);
local blocking = module:get_option_boolean("external_auth_blocking", true); -- non-blocking is very experimental
local auth_processes = module:get_option_number("external_auth_processes", 1);
assert(script_type == "ejabberd" or script_type == "generic",
"Config error: external_auth_protocol must be 'ejabberd' or 'generic'");
assert(not host:find(":"), "Invalid hostname");
if not blocking then
assert(server.event, "External auth non-blocking mode requires libevent installed and enabled");
log("debug", "External auth in non-blocking mode, yay!")
waiter, guard = async.waiter, async.guarder();
elseif auth_processes > 1 then
log("warn", "external_auth_processes is greater than 1, but we are in blocking mode - reducing to 1");
auth_processes = 1;
end
local ptys = {};
local pty_options = { throw_errors = false, no_local_echo = true, use_path = false };
for i = 1, auth_processes do
ptys[i] = lpty.new(pty_options);
end
function module.unload()
for i = 1, auth_processes do
ptys[i]:endproc();
end
end
module:hook_global("server-cleanup", module.unload);
local curr_process = 0;
function send_query(text)
curr_process = (curr_process%auth_processes)+1;
local pty = ptys[curr_process];
local finished_with_pty
if not blocking then
finished_with_pty = guard(pty); -- Prevent others from crossing this line while we're busy
end
if not pty:hasproc() then
local status, ret = pty:exitstatus();
if status and (status ~= "exit" or ret ~= 0) then
log("warn", "Auth process exited unexpectedly with %s %d, restarting", status, ret or 0);
return nil;
end
local ok, err = pty:startproc(command);
if not ok then
log("error", "Failed to start auth process '%s': %s", command, err);
return nil;
end
log("debug", "Started auth process");
end
pty:send(text);
if blocking then
return pty:read(read_timeout);
else
local response;
local wait, done = waiter();
server.addevent(pty:getfd(), server.event.EV_READ, function ()
response = pty:read();
done();
return -1;
end);
wait();
finished_with_pty();
return response;
end
end
function do_query(kind, username, password)
if not username then return nil, "not-acceptable"; end
local query = (password and "%s:%s:%s:%s" or "%s:%s:%s"):format(kind, username, host, password);
local len = #query
if len > 1000 then return nil, "policy-violation"; end
if script_type == "ejabberd" then
local lo = len % 256;
local hi = (len - lo) / 256;
query = string.char(hi, lo)..query;
elseif script_type == "generic" then
query = query..'\n';
end
local response, err = send_query(query);
if not response then
log("warn", "Error while waiting for result from auth process: %s", err or "unknown error");
elseif (script_type == "ejabberd" and response == "\0\2\0\0") or
(script_type == "generic" and response:gsub("\r?\n$", "") == "0") then
return nil, "not-authorized";
elseif (script_type == "ejabberd" and response == "\0\2\0\1") or
(script_type == "generic" and response:gsub("\r?\n$", "") == "1") then
return true;
else
log("warn", "Unable to interpret data from auth process, %s",
(response:match("^error:") and response) or ("["..#response.." bytes]"));
return nil, "internal-server-error";
end
end
local provider = {};
function provider.test_password(username, password)
return do_query("auth", username, password);
end
function provider.set_password(username, password)
return do_query("setpass", username, password);
end
function provider.user_exists(username)
return do_query("isuser", username);
end
function provider.create_user(username, password) -- luacheck: ignore 212
return nil, "Account creation/modification not available.";
end
function provider.get_sasl_handler()
local testpass_authentication_profile = {
plain_test = function(sasl, username, password, realm)
return usermanager.test_password(username, realm, password), true;
end,
};
return new_sasl(host, testpass_authentication_profile);
end
module:provides("auth", provider);