aboutsummaryrefslogtreecommitdiffstats
path: root/plugins/mod_saslauth.lua
blob: 81113d7cdec327a16d859cdabb832915b7a98078 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
-- Prosody IM v0.4
-- Copyright (C) 2008-2009 Matthew Wild
-- Copyright (C) 2008-2009 Waqas Hussain
-- 
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--



local st = require "util.stanza";
local sm_bind_resource = require "core.sessionmanager".bind_resource;
local sm_make_authenticated = require "core.sessionmanager".make_authenticated;
local base64 = require "util.encodings".base64;

local datamanager_load = require "util.datamanager".load;
local usermanager_validate_credentials = require "core.usermanager".validate_credentials;
local t_concat, t_insert = table.concat, table.insert;
local tostring = tostring;
local jid_split = require "util.jid".split
local md5 = require "util.hashes".md5;
local config = require "core.configmanager";

local secure_auth_only = config.get(module:get_host(), "core", "require_encryption");

local log = module._log;

local xmlns_sasl ='urn:ietf:params:xml:ns:xmpp-sasl';
local xmlns_bind ='urn:ietf:params:xml:ns:xmpp-bind';
local xmlns_stanzas ='urn:ietf:params:xml:ns:xmpp-stanzas';

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

local function build_reply(status, ret, err_msg)
	local reply = st.stanza(status, {xmlns = xmlns_sasl});
	if status == "challenge" then
		log("debug", "%s", ret or "");
		reply:text(base64.encode(ret or ""));
	elseif status == "failure" then
		reply:tag(ret):up();
		if err_msg then reply:tag("text"):text(err_msg); end
	elseif status == "success" then
		log("debug", "%s", ret or "");
		reply:text(base64.encode(ret or ""));
	else
		module:log("error", "Unknown sasl status: %s", status);
	end
	return reply;
end

local function handle_status(session, status)
	if status == "failure" then
		session.sasl_handler = nil;
	elseif status == "success" then
		if not session.sasl_handler.username then -- TODO move this to sessionmanager
			module:log("warn", "SASL succeeded but we didn't get a username!");
			session.sasl_handler = nil;
			session:reset_stream();
			return;
		end 
		sm_make_authenticated(session, session.sasl_handler.username);
		session.sasl_handler = nil;
		session:reset_stream();
	end
end

local function password_callback(node, hostname, realm, mechanism, decoder)
	local password = (datamanager_load(node, hostname, "accounts") or {}).password; -- FIXME handle hashed passwords
	local func = function(x) return x; end;
	if password then
		if mechanism == "PLAIN" then
			return func, password;
		elseif mechanism == "DIGEST-MD5" then
			if decoder then node, realm, password = decoder(node), decoder(realm), decoder(password); end
			return func, md5(node..":"..realm..":"..password);
		end
	end
	return func, nil;
end

local function sasl_handler(session, stanza)
	if stanza.name == "auth" then
		-- FIXME ignoring duplicates because ejabberd does
		if config.get(session.host or "*", "core", "anonymous_login") then
			if stanza.attr.mechanism ~= "ANONYMOUS" then
				return session.send(build_reply("failure", "invalid-mechanism"));
			end
		elseif stanza.attr.mechanism == "ANONYMOUS" then
			return session.send(build_reply("failure", "mechanism-too-weak"));
		end
		session.sasl_handler = new_sasl(stanza.attr.mechanism, session.host, password_callback);
		if not session.sasl_handler then
			return session.send(build_reply("failure", "invalid-mechanism"));
		end
	elseif not session.sasl_handler then
		return; -- FIXME ignoring out of order stanzas because ejabberd does
	end
	local text = stanza[1];
	if text then
		text = base64.decode(text);
		log("debug", "%s", text);
		if not text then
			session.sasl_handler = nil;
			session.send(build_reply("failure", "incorrect-encoding"));
			return;
		end
	end
	local status, ret, err_msg = session.sasl_handler:feed(text);
	handle_status(session, status);
	local s = build_reply(status, ret, err_msg); 
	log("debug", "sasl reply: %s", tostring(s));
	session.send(s);
end

module:add_handler("c2s_unauthed", "auth", xmlns_sasl, sasl_handler);
module:add_handler("c2s_unauthed", "abort", xmlns_sasl, sasl_handler);
module:add_handler("c2s_unauthed", "response", xmlns_sasl, sasl_handler);

local mechanisms_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-sasl' };
local bind_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-bind' };
local xmpp_session_attr = { xmlns='urn:ietf:params:xml:ns:xmpp-session' };
module:add_event_hook("stream-features", 
		function (session, features)												
			if not session.username then
				if secure_auth_only and not session.secure then
					return;
				end
				features:tag("mechanisms", mechanisms_attr);
				-- TODO: Provide PLAIN only if TLS is active, this is a SHOULD from the introduction of RFC 4616. This behavior could be overridden via configuration but will issuing a warning or so.
					if config.get(session.host or "*", "core", "anonymous_login") then
						features:tag("mechanism"):text("ANONYMOUS"):up();
					else
						features:tag("mechanism"):text("DIGEST-MD5"):up();
						features:tag("mechanism"):text("PLAIN"):up();
					end
				features:up();
			else
				features:tag("bind", bind_attr):tag("required"):up():up();
				features:tag("session", xmpp_session_attr):up();
			end
		end);
					
module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-bind", 
		function (session, stanza)
			log("debug", "Client requesting a resource bind");
			local resource;
			if stanza.attr.type == "set" then
				local bind = stanza.tags[1];
				if bind and bind.attr.xmlns == xmlns_bind then
					resource = bind:child_with_name("resource");
					if resource then
						resource = resource[1];
					end
				end
			end
			local success, err_type, err, err_msg = sm_bind_resource(session, resource);
			if not success then
				session.send(st.error_reply(stanza, err_type, err, err_msg));
			else
				session.send(st.reply(stanza)
					:tag("bind", { xmlns = xmlns_bind})
					:tag("jid"):text(session.full_jid));
			end
		end);
		
module:add_iq_handler("c2s", "urn:ietf:params:xml:ns:xmpp-session", 
		function (session, stanza)
			log("debug", "Client requesting a session");
			session.send(st.reply(stanza));
		end);