mod_auth_cyrus: Add empty 'profile' table to SASL handler objects This is for compatibility with Prosody's built-in util.sasl objects. A SASL profile table usually includes methods supported by the backend, which can be used by SASL mechanism handlers to perform operations (such as testing the password). It also optionally contains a 'cb' field with channel binding method handlers. The Cyrus backend doesn't support channel binding, and doesn't have the same concept of auth backend methods (it handles all that internally, and Prosody has no insight or control over it). Thus, we create an empty profile which informs Prosody that the SASL handler does not support any of the auth or channel binding methods. Some features will not work, but they didn't work anyway. This just makes it explicit. This fixes a traceback in mod_sasl2_fast, which expected SASL handlers to always contain a 'profile' field.

-- PAM authentication for Prosody
-- Copyright (C) 2013 Kim Alvefur
--
-- Requires https://github.com/devurandom/lua-pam
-- and LuaPosix

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

function user_exists(username)
	return not not posix.getpasswd(username);
end

function test_password(username, password)
	local h, err = pam.start("xmpp", username, {
		function (t)
			if #t == 1 and t[1][1] == pam.PROMPT_ECHO_OFF then
				return { { password, 0} };
			end
		end
	});
	if h and h:authenticate() and h:endx(pam.SUCCESS) then
		return user_exists(username), true;
	end
	return nil, true;
end

function get_sasl_handler()
	return new_sasl(module.host, {
		plain_test = function(sasl, ...)
			return test_password(...)
		end
	});
end

module:provides"auth";