aboutsummaryrefslogtreecommitdiffstats
path: root/plugins/mod_tokenauth.lua
blob: cb2b63c2e0066ff8345b74039c4db86cd72aa27c (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
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
local base64 = require "prosody.util.encodings".base64;
local hashes = require "prosody.util.hashes";
local id = require "prosody.util.id";
local jid = require "prosody.util.jid";
local random = require "prosody.util.random";
local usermanager = require "prosody.core.usermanager";
local generate_identifier = require "prosody.util.id".short;

local token_store = module:open_store("auth_tokens", "keyval+");

local access_time_granularity = module:get_option_period("token_auth_access_time_granularity", 60);
local empty_grant_lifetime = module:get_option_period("tokenless_grant_ttl", "2w");

local function select_role(username, host, role_name)
	if not role_name then return end
	local role = usermanager.get_role_by_name(role_name, host);
	if not role then return end
	if not usermanager.user_can_assume_role(username, host, role.name) then return end
	return role;
end

function create_grant(actor_jid, grant_jid, grant_ttl, grant_data)
	grant_jid = jid.prep(grant_jid);
	if not actor_jid or actor_jid ~= grant_jid and not jid.compare(grant_jid, actor_jid) then
		module:log("debug", "Actor <%s> is not permitted to create a token granting access to JID <%s>", actor_jid, grant_jid);
		return nil, "not-authorized";
	end

	local grant_username, grant_host, grant_resource = jid.split(grant_jid);

	if grant_host ~= module.host then
		return nil, "invalid-host";
	end

	local grant_id = id.short();
	local now = os.time();

	local grant = {
		id = grant_id;

		owner = actor_jid;
		created = now;
		expires = grant_ttl and (now + grant_ttl) or nil;
		accessed = now;

		jid = grant_jid;
		resource = grant_resource;

		data = grant_data;

		-- tokens[<hash-name>..":"..<secret>] = token_info
		tokens = {};
	};

	local ok, err = token_store:set_key(grant_username, grant_id, grant);
	if not ok then
		return nil, err;
	end

	module:fire_event("token-grant-created", {
		id = grant_id;
		grant = grant;
		username = grant_username;
		host = grant_host;
	});

	return grant;
end

function create_token(grant_jid, grant, token_role, token_ttl, token_purpose, token_data)
	if (token_data and type(token_data) ~= "table") or (token_purpose and type(token_purpose) ~= "string") then
		return nil, "bad-request";
	end
	local grant_username, grant_host = jid.split(grant_jid);
	if grant_host ~= module.host then
		return nil, "invalid-host";
	end
	if type(grant) == "string" then -- lookup by id
		grant = token_store:get_key(grant_username, grant);
		if not grant then return nil; end
	end

	if not grant.tokens then return nil, "internal-server-error"; end -- old-style token?

	local now = os.time();
	local expires = grant.expires; -- Default to same expiry as grant
	if token_ttl then -- explicit lifetime requested
		if expires then
			-- Grant has an expiry, so limit to that or shorter
			expires = math.min(now + token_ttl, expires);
		else
			-- Grant never expires, just use whatever expiry is requested for the token
			expires = now + token_ttl;
		end
	end

	local token_info = {
		role = token_role;

		created = now;
		expires = expires;
		purpose = token_purpose;

		data = token_data;
	};

	local token_secret = random.bytes(18);
	grant.tokens["sha256:"..hashes.sha256(token_secret, true)] = token_info;

	local ok, err = token_store:set_key(grant_username, grant.id, grant);
	if not ok then
		return nil, err;
	end

	local token_string = "secret-token:"..base64.encode("2;"..grant.id..";"..token_secret..";"..grant.jid);
	return token_string, token_info;
end

local function parse_token(encoded_token)
	if not encoded_token then return nil; end
	local encoded_data = encoded_token:match("^secret%-token:(.+)$");
	if not encoded_data then return nil; end
	local token = base64.decode(encoded_data);
	if not token then return nil; end
	local token_id, token_secret, token_jid = token:match("^2;([^;]+);(..................);(.+)$");
	if not token_id then return nil; end
	local token_user, token_host = jid.split(token_jid);
	return token_id, token_user, token_host, token_secret;
end

local function clear_expired_grant_tokens(grant, now)
	local updated;
	now = now or os.time();
	for secret, token_info in pairs(grant.tokens) do
		local expires = token_info.expires;
		if expires and expires < now then
			grant.tokens[secret] = nil;
			updated = true;
		end
	end
	return updated;
end

local function _get_validated_grant_info(username, grant)
	if type(grant) == "string" then
		grant = token_store:get_key(username, grant);
	end
	if not grant or not grant.created then return nil; end

	-- Invalidate grants from before last password change
	local account_info = usermanager.get_account_info(username, module.host);
	local password_updated_at = account_info and account_info.password_updated;
	local now = os.time();
	if password_updated_at and grant.created < password_updated_at then
		module:log("debug", "Token grant %s of %s issued before last password change, invalidating it now", grant.id, username);
		token_store:set_key(username, grant.id, nil);
		return nil, "not-authorized";
	elseif grant.expires and grant.expires < now then
		module:log("debug", "Token grant %s of %s expired, cleaning up", grant.id, username);
		token_store:set_key(username, grant.id, nil);
		return nil, "expired";
	end

	if not grant.tokens then
		module:log("debug", "Token grant %s of %s without tokens, cleaning up", grant.id, username);
		token_store:set_key(username, grant.id, nil);
		return nil, "invalid";
	end

	local found_expired = false
	for secret_hash, token_info in pairs(grant.tokens) do
		if token_info.expires and token_info.expires < now then
			module:log("debug", "Token %s of grant %s of %s has expired, cleaning it up", secret_hash:sub(-8), grant.id, username);
			grant.tokens[secret_hash] = nil;
			found_expired = true;
		end
	end

	if not grant.expires and next(grant.tokens) == nil and grant.accessed + empty_grant_lifetime < now then
		module:log("debug", "Token %s of %s grant has no tokens, discarding", grant.id, username);
		token_store:set_key(username, grant.id, nil);
		return nil, "expired";
	elseif found_expired then
		token_store:set_key(username, grant.id, grant);
	end

	return grant;
end

local function _get_validated_token_info(token_id, token_user, token_host, token_secret)
	if token_host ~= module.host then
		return nil, "invalid-host";
	end

	local grant, err = token_store:get_key(token_user, token_id);
	if not grant or not grant.tokens then
		if err then
			module:log("error", "Unable to read from token storage: %s", err);
			return nil, "internal-error";
		end
		module:log("warn", "Invalid token in storage (%s / %s)", token_user, token_id);
		return nil, "not-authorized";
	end

	-- Check provided secret
	local secret_hash = "sha256:"..hashes.sha256(token_secret, true);
	local token_info = grant.tokens[secret_hash];
	if not token_info then
		module:log("debug", "No tokens matched the given secret");
		return nil, "not-authorized";
	end

	-- Check expiry
	local now = os.time();
	if token_info.expires and token_info.expires < now then
		module:log("debug", "Token has expired, cleaning it up");
		grant.tokens[secret_hash] = nil;
		token_store:set_key(token_user, token_id, grant);
		return nil, "not-authorized";
	end

	-- Verify grant validity (expiry, etc.)
	grant = _get_validated_grant_info(token_user, grant);
	if not grant then
		return nil, "not-authorized";
	end

	-- Update last access time if necessary
	local last_accessed = grant.accessed;
	if not last_accessed or (now - last_accessed) > access_time_granularity then
		grant.accessed = now;
		clear_expired_grant_tokens(grant); -- Clear expired tokens while we're here
		token_store:set_key(token_user, token_id, grant);
	end

	token_info.id = token_id;
	token_info.grant = grant;
	token_info.jid = grant.jid;

	return token_info;
end

function get_grant_info(username, grant_id)
	local grant = _get_validated_grant_info(username, grant_id);
	if not grant then return nil; end

	-- Caller is only interested in the grant, no need to expose token stuff to them
	grant.tokens = nil;

	return grant;
end

function get_user_grants(username)
	local grants = token_store:get(username);
	if not grants then return nil; end
	for grant_id, grant in pairs(grants) do
		grants[grant_id] = _get_validated_grant_info(username, grant);
	end
	return grants;
end

function get_token_info(token)
	local token_id, token_user, token_host, token_secret = parse_token(token);
	if not token_id then
		module:log("warn", "Failed to verify access token: %s", token_user);
		return nil, "invalid-token-format";
	end
	return _get_validated_token_info(token_id, token_user, token_host, token_secret);
end

function get_token_session(token, resource)
	local token_id, token_user, token_host, token_secret = parse_token(token);
	if not token_id then
		module:log("warn", "Failed to verify access token: %s", token_user);
		return nil, "invalid-token-format";
	end

	local token_info, err = _get_validated_token_info(token_id, token_user, token_host, token_secret);
	if not token_info then return nil, err; end

	local role = select_role(token_user, token_host, token_info.role);
	if not role then return nil, "not-authorized"; end
	return {
		username = token_user;
		host = token_host;
		resource = token_info.resource or resource or generate_identifier();

		role = role;
	};
end

function revoke_token(token)
	local grant_id, token_user, token_host, token_secret = parse_token(token);
	if not grant_id then
		module:log("warn", "Failed to verify access token: %s", token_user);
		return nil, "invalid-token-format";
	end
	if token_host ~= module.host then
		return nil, "invalid-host";
	end
	local grant, err = _get_validated_grant_info(token_user, grant_id);
	if not grant then return grant, err; end
	local secret_hash = "sha256:"..hashes.sha256(token_secret, true);
	local token_info = grant.tokens[secret_hash];
	if not grant or not token_info then
		return nil, "item-not-found";
	end
	grant.tokens[secret_hash] = nil;
	local ok, err = token_store:set_key(token_user, grant_id, grant);
	if not ok then
		return nil, err;
	end
	module:fire_event("token-revoked", {
		grant_id = grant_id;
		grant = grant;
		info = token_info;
		username = token_user;
		host = token_host;
	});
	return true;
end

function revoke_grant(username, grant_id)
	local ok, err = token_store:set_key(username, grant_id, nil);
	if not ok then return nil, err; end
	module:fire_event("token-grant-revoked", { id = grant_id, username = username, host = module.host });
	return true;
end

function sasl_handler(auth_provider, purpose, extra)
	return function (sasl, token, realm, _authzid)
		local token_info, err = get_token_info(token);
		if not token_info then
			module:log("debug", "SASL handler failed to verify token: %s", err);
			return nil, nil, extra;
		end
		local token_user, token_host, resource = jid.split(token_info.grant.jid);
		if realm ~= token_host or (purpose and token_info.purpose ~= purpose) then
			return nil, nil, extra;
		end
		if auth_provider.is_enabled and not auth_provider.is_enabled(token_user) then
			return true, false, token_info;
		end
		sasl.resource = resource;
		sasl.token_info = token_info;
		return token_user, true, token_info;
	end;
end

module:daily("clear expired grants", function()
	for username in token_store:items() do
		get_user_grants(username); -- clears out expired grants
	end
end)