aboutsummaryrefslogtreecommitdiffstats
path: root/plugins/mod_saslauth.lua
blob: 4906d01f6fa9f6d52ad7f3448268c13615b879cf (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
171
-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 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 nodeprep = require "util.encodings".stringprep.nodeprep;
local usermanager_get_sasl_handler = require "core.usermanager".get_sasl_handler;
local tostring = tostring;

local secure_auth_only = module:get_option("c2s_require_encryption") or module:get_option("require_encryption");
local allow_unencrypted_plain_auth = module:get_option("allow_unencrypted_plain_auth")

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 function build_reply(status, ret, err_msg)
	local reply = st.stanza(status, {xmlns = xmlns_sasl});
	if status == "challenge" then
		--log("debug", "CHALLENGE: %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", "SUCCESS: %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, ret, err_msg)
	if status == "failure" then
		session.sasl_handler = session.sasl_handler:clean_clone();
	elseif status == "success" then
		local username = nodeprep(session.sasl_handler.username);

		local ok, err = sm_make_authenticated(session, session.sasl_handler.username);
		if ok then
			session.sasl_handler = nil;
			session:reset_stream();
		else
			module:log("warn", "SASL succeeded but username was invalid");
			session.sasl_handler = session.sasl_handler:clean_clone();
			return "failure", "not-authorized", "User authenticated successfully, but username was invalid";
		end
	end
	return status, ret, err_msg;
end

local function sasl_process_cdata(session, stanza)
	local text = stanza[1];
	if text then
		text = base64.decode(text);
		--log("debug", "AUTH: %s", text:gsub("[%z\001-\008\011\012\014-\031]", " "));
		if not text then
			session.sasl_handler = nil;
			session.send(build_reply("failure", "incorrect-encoding"));
			return true;
		end
	end
	local status, ret, err_msg = session.sasl_handler:process(text);
	status, ret, err_msg = handle_status(session, status, ret, err_msg);
	local s = build_reply(status, ret, err_msg);
	log("debug", "sasl reply: %s", tostring(s));
	session.send(s);
	return true;
end

module:hook("stanza/urn:ietf:params:xml:ns:xmpp-sasl:auth", function(event)
	local session, stanza = event.origin, event.stanza;
	if session.type ~= "c2s_unauthed" then return; end

	if session.sasl_handler and session.sasl_handler.selected then
		session.sasl_handler = nil; -- allow starting a new SASL negotiation before completing an old one
	end
	if not session.sasl_handler then
		session.sasl_handler = usermanager_get_sasl_handler(module.host);
	end
	local mechanism = stanza.attr.mechanism;
	if not session.secure and (secure_auth_only or (mechanism == "PLAIN" and not allow_unencrypted_plain_auth)) then
		session.send(build_reply("failure", "encryption-required"));
		return true;
	end
	local valid_mechanism = session.sasl_handler:select(mechanism);
	if not valid_mechanism then
		session.send(build_reply("failure", "invalid-mechanism"));
		return true;
	end
	return sasl_process_cdata(session, stanza);
end);
module:hook("stanza/urn:ietf:params:xml:ns:xmpp-sasl:response", function(event)
	local session = event.origin;
	if not(session.sasl_handler and session.sasl_handler.selected) then
		session.send(build_reply("failure", "not-authorized", "Out of order SASL element"));
		return true;
	end
	return sasl_process_cdata(session, event.stanza);
end);
module:hook("stanza/urn:ietf:params:xml:ns:xmpp-sasl:abort", function(event)
	local session = event.origin;
	session.sasl_handler = nil;
	session.send(build_reply("failure", "aborted"));
	return true;
end);

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:hook("stream-features", function(event)
	local origin, features = event.origin, event.features;
	if not origin.username then
		if secure_auth_only and not origin.secure then
			return;
		end
		origin.sasl_handler = usermanager_get_sasl_handler(module.host);
		features:tag("mechanisms", mechanisms_attr);
		for mechanism in pairs(origin.sasl_handler:mechanisms()) do
			if mechanism ~= "PLAIN" or origin.secure or allow_unencrypted_plain_auth then
				features:tag("mechanism"):text(mechanism):up();
			end
		end
		features:up();
	else
		features:tag("bind", bind_attr):tag("required"):up():up();
		features:tag("session", xmpp_session_attr):tag("optional"):up():up();
	end
end);

module:hook("iq/self/urn:ietf:params:xml:ns:xmpp-bind:bind", function(event)
	local origin, stanza = event.origin, event.stanza;
	local resource;
	if stanza.attr.type == "set" then
		local bind = stanza.tags[1];
		resource = bind:child_with_name("resource");
		resource = resource and #resource.tags == 0 and resource[1] or nil;
	end
	local success, err_type, err, err_msg = sm_bind_resource(origin, resource);
	if success then
		origin.send(st.reply(stanza)
			:tag("bind", { xmlns = xmlns_bind })
			:tag("jid"):text(origin.full_jid));
		origin.log("debug", "Resource bound: %s", origin.full_jid);
	else
		origin.send(st.error_reply(stanza, err_type, err, err_msg));
		origin.log("debug", "Resource bind failed: %s", err_msg or err);
	end
	return true;
end);

local function handle_legacy_session(event)
	event.origin.send(st.reply(event.stanza));
	return true;
end

module:hook("iq/self/urn:ietf:params:xml:ns:xmpp-session:session", handle_legacy_session);
module:hook("iq/host/urn:ietf:params:xml:ns:xmpp-session:session", handle_legacy_session);