Line data Source code
1 : /*
2 : This file is part of TALER
3 : Copyright (C) 2014-2023 Taler Systems SA
4 :
5 : TALER is free software; you can redistribute it and/or modify it under the
6 : terms of the GNU Affero General Public License as published by the Free Software
7 : Foundation; either version 3, or (at your option) any later version.
8 :
9 : TALER is distributed in the hope that it will be useful, but WITHOUT ANY
10 : WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
11 : A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.
12 :
13 : You should have received a copy of the GNU Affero General Public License along with
14 : TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
15 : */
16 : /**
17 : * @file taler-auditor-httpd_put-deposit-confirmation.c
18 : * @brief Handle /deposit-confirmation requests; parses the POST and JSON and
19 : * verifies the coin signature before handing things off
20 : * to the database.
21 : * @author Christian Grothoff
22 : */
23 : #include <gnunet/gnunet_util_lib.h>
24 : #include <gnunet/gnunet_json_lib.h>
25 : #include <jansson.h>
26 : #include <microhttpd.h>
27 : #include <pthread.h>
28 : #include "taler/taler_json_lib.h"
29 : #include "taler/taler_mhd_lib.h"
30 : #include "taler-auditor-httpd.h"
31 : #include "taler-auditor-httpd_put-deposit-confirmation.h"
32 : #include "exchange-database/get_signkey_revocation.h"
33 : #include "auditor-database/insert_deposit_confirmation.h"
34 : #include "auditor-database/insert_exchange_signkey.h"
35 : #include "auditor-database/preflight.h"
36 :
37 : GNUNET_NETWORK_STRUCT_BEGIN
38 :
39 : /**
40 : * @brief Information about a signing key of the exchange. Signing keys are used
41 : * to sign exchange messages other than coins, i.e. to confirm that a
42 : * deposit was successful or that a refresh was accepted.
43 : */
44 : struct ExchangeSigningKeyDataP
45 : {
46 :
47 : /**
48 : * When does this signing key begin to be valid?
49 : */
50 : struct GNUNET_TIME_TimestampNBO start;
51 :
52 : /**
53 : * When does this signing key expire? Note: This is currently when
54 : * the Exchange will definitively stop using it. Signatures made with
55 : * the key remain valid until @e end. When checking validity periods,
56 : * clients should allow for some overlap between keys and tolerate
57 : * the use of either key during the overlap time (due to the
58 : * possibility of clock skew).
59 : */
60 : struct GNUNET_TIME_TimestampNBO expire;
61 :
62 : /**
63 : * When do signatures with this signing key become invalid? After
64 : * this point, these signatures cannot be used in (legal) disputes
65 : * anymore, as the Exchange is then allowed to destroy its side of the
66 : * evidence. @e end is expected to be significantly larger than @e
67 : * expire (by a year or more).
68 : */
69 : struct GNUNET_TIME_TimestampNBO end;
70 :
71 : /**
72 : * The public online signing key that the exchange will use
73 : * between @e start and @e expire.
74 : */
75 : struct TALER_ExchangePublicKeyP signkey_pub;
76 : };
77 :
78 : GNUNET_NETWORK_STRUCT_END
79 :
80 :
81 : /**
82 : * Cache of already verified exchange signing keys. Maps the hash of the
83 : * `struct TALER_ExchangeSigningKeyValidityPS` to the (static) string
84 : * "verified" or "revoked". Access to this map is guarded by the #lock.
85 : */
86 : static struct GNUNET_CONTAINER_MultiHashMap *cache;
87 :
88 : /**
89 : * Lock for operations on #cache.
90 : */
91 : static pthread_mutex_t lock;
92 :
93 :
94 : /**
95 : * We have parsed the JSON information about the deposit, do some
96 : * basic sanity checks (especially that the signature on the coin is
97 : * valid, and that this type of coin exists) and then execute the
98 : * deposit.
99 : *
100 : * @param connection the MHD connection to handle
101 : * @param dc information about the deposit confirmation
102 : * @param es information about the exchange's signing key
103 : * @return MHD result code
104 : */
105 : static enum MHD_Result
106 2 : verify_and_execute_deposit_confirmation (
107 : struct MHD_Connection *connection,
108 : const struct TALER_AUDITORDB_DepositConfirmation *dc,
109 : const struct TALER_AUDITORDB_ExchangeSigningKey *es)
110 2 : {
111 : enum GNUNET_DB_QueryStatus qs;
112 : struct GNUNET_HashCode h;
113 : const char *cached;
114 2 : struct ExchangeSigningKeyDataP skv = {
115 2 : .start = GNUNET_TIME_timestamp_hton (es->ep_start),
116 2 : .expire = GNUNET_TIME_timestamp_hton (es->ep_expire),
117 2 : .end = GNUNET_TIME_timestamp_hton (es->ep_end),
118 : .signkey_pub = es->exchange_pub
119 : };
120 0 : const struct TALER_CoinSpendSignatureP *coin_sigps[
121 2 : GNUNET_NZL (dc->num_coins)];
122 :
123 4 : for (unsigned int i = 0; i < dc->num_coins; i++)
124 2 : coin_sigps[i] = &dc->coin_sigs[i];
125 :
126 4 : if (GNUNET_TIME_absolute_is_future (es->ep_start.abs_time) ||
127 2 : GNUNET_TIME_absolute_is_past (es->ep_expire.abs_time))
128 : {
129 : /* Signing key expired */
130 0 : TALER_LOG_WARNING ("Expired exchange signing key\n");
131 0 : return TALER_MHD_reply_with_error (connection,
132 : MHD_HTTP_FORBIDDEN,
133 : TALER_EC_AUDITOR_DEPOSIT_CONFIRMATION_SIGNATURE_INVALID,
134 : "master signature expired");
135 : }
136 :
137 : /* check our cache */
138 2 : GNUNET_CRYPTO_hash (&skv,
139 : sizeof(skv),
140 : &h);
141 2 : GNUNET_assert (0 == pthread_mutex_lock (&lock));
142 2 : cached = GNUNET_CONTAINER_multihashmap_get (cache,
143 : &h);
144 2 : GNUNET_assert (0 == pthread_mutex_unlock (&lock));
145 2 : if (GNUNET_SYSERR ==
146 2 : TALER_AUDITORDB_preflight (TAH_apg))
147 : {
148 0 : GNUNET_break (0);
149 0 : return TALER_MHD_reply_with_error (connection,
150 : MHD_HTTP_INTERNAL_SERVER_ERROR,
151 : TALER_EC_GENERIC_DB_SETUP_FAILED,
152 : NULL);
153 : }
154 2 : if (NULL == cached)
155 : {
156 : /* Not in cache, need to verify the signature, persist it, and possibly cache it */
157 2 : if (GNUNET_OK !=
158 2 : TALER_exchange_offline_signkey_validity_verify (
159 : &es->exchange_pub,
160 : es->ep_start,
161 : es->ep_expire,
162 : es->ep_end,
163 : &TAH_master_public_key,
164 : &es->master_sig))
165 : {
166 0 : TALER_LOG_WARNING ("Invalid signature on exchange signing key\n");
167 0 : return TALER_MHD_reply_with_error (connection,
168 : MHD_HTTP_FORBIDDEN,
169 : TALER_EC_AUDITOR_DEPOSIT_CONFIRMATION_SIGNATURE_INVALID,
170 : "master signature invalid");
171 : }
172 :
173 : /* execute transaction */
174 2 : qs = TALER_AUDITORDB_insert_exchange_signkey (TAH_apg,
175 : es);
176 2 : if (0 > qs)
177 : {
178 0 : GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR == qs);
179 0 : TALER_LOG_WARNING ("Failed to store exchange signing key in database\n");
180 0 : return TALER_MHD_reply_with_error (connection,
181 : MHD_HTTP_INTERNAL_SERVER_ERROR,
182 : TALER_EC_GENERIC_DB_STORE_FAILED,
183 : "exchange signing key");
184 : }
185 2 : cached = "verified";
186 : }
187 :
188 2 : if (0 == strcmp (cached,
189 : "verified"))
190 : {
191 : struct TALER_MasterSignatureP master_sig;
192 :
193 : /* check for revocation */
194 2 : qs = TALER_EXCHANGEDB_get_signkey_revocation (TAH_epg,
195 : &es->exchange_pub,
196 : &master_sig);
197 2 : if (0 > qs)
198 : {
199 0 : GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR == qs);
200 0 : TALER_LOG_WARNING (
201 : "Failed to check for signing key revocation in database\n");
202 0 : return TALER_MHD_reply_with_error (connection,
203 : MHD_HTTP_INTERNAL_SERVER_ERROR,
204 : TALER_EC_GENERIC_DB_FETCH_FAILED,
205 : "exchange signing key revocation");
206 : }
207 2 : if (0 < qs)
208 0 : cached = "revoked";
209 : }
210 :
211 : /* Cache it, due to concurreny it might already be in the cache,
212 : so we do not cache it twice but also don't insist on the 'put' to
213 : succeed. */
214 2 : GNUNET_assert (0 == pthread_mutex_lock (&lock));
215 2 : (void) GNUNET_CONTAINER_multihashmap_put (cache,
216 : &h,
217 : (void *) cached,
218 : GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
219 2 : GNUNET_assert (0 == pthread_mutex_unlock (&lock));
220 :
221 2 : if (0 == strcmp (cached,
222 : "revoked"))
223 : {
224 0 : TALER_LOG_WARNING (
225 : "Invalid signature on /deposit-confirmation request: key was revoked\n");
226 0 : return TALER_MHD_reply_with_error (connection,
227 : MHD_HTTP_GONE,
228 : TALER_EC_AUDITOR_EXCHANGE_SIGNING_KEY_REVOKED,
229 : "exchange signing key was revoked");
230 : }
231 :
232 : /* check deposit confirmation signature */
233 2 : if (GNUNET_OK !=
234 2 : TALER_exchange_online_deposit_confirmation_verify (
235 : &dc->h_contract_terms,
236 : &dc->h_wire,
237 : &dc->h_policy,
238 : dc->exchange_timestamp,
239 : dc->wire_deadline,
240 : dc->refund_deadline,
241 : &dc->total_without_fee,
242 2 : dc->num_coins,
243 : coin_sigps,
244 : &dc->merchant,
245 : &dc->exchange_pub,
246 : &dc->exchange_sig))
247 : {
248 0 : TALER_LOG_WARNING (
249 : "Invalid signature on /deposit-confirmation request\n");
250 0 : return TALER_MHD_reply_with_error (connection,
251 : MHD_HTTP_FORBIDDEN,
252 : TALER_EC_AUDITOR_DEPOSIT_CONFIRMATION_SIGNATURE_INVALID,
253 : "exchange signature invalid");
254 : }
255 :
256 : /* execute transaction */
257 2 : qs = TALER_AUDITORDB_insert_deposit_confirmation (TAH_apg,
258 : dc);
259 2 : if (0 > qs)
260 : {
261 0 : GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR == qs);
262 0 : TALER_LOG_WARNING ("Failed to store /deposit-confirmation in database\n");
263 0 : return TALER_MHD_reply_with_error (connection,
264 : MHD_HTTP_INTERNAL_SERVER_ERROR,
265 : TALER_EC_GENERIC_DB_STORE_FAILED,
266 : "deposit confirmation");
267 : }
268 2 : return TALER_MHD_reply_static (connection,
269 : MHD_HTTP_NO_CONTENT,
270 : NULL,
271 : NULL,
272 : 0);
273 : }
274 :
275 :
276 : enum MHD_Result
277 6 : TAH_put_deposit_confirmation (
278 : struct TAH_RequestHandler *rh,
279 : struct MHD_Connection *connection,
280 : void **connection_cls,
281 : const char *upload_data,
282 : size_t *upload_data_size,
283 : const char *const args[])
284 : {
285 6 : struct TALER_AUDITORDB_DepositConfirmation dc = {
286 : .refund_deadline = GNUNET_TIME_UNIT_ZERO_TS
287 : };
288 : struct TALER_AUDITORDB_ExchangeSigningKey es;
289 : const json_t *jcoin_sigs;
290 : const json_t *jcoin_pubs;
291 : struct GNUNET_JSON_Specification spec[] = {
292 6 : GNUNET_JSON_spec_fixed_auto ("h_contract_terms",
293 : &dc.h_contract_terms),
294 6 : GNUNET_JSON_spec_fixed_auto ("h_policy",
295 : &dc.h_policy),
296 6 : GNUNET_JSON_spec_fixed_auto ("h_wire",
297 : &dc.h_wire),
298 6 : GNUNET_JSON_spec_timestamp ("exchange_timestamp",
299 : &dc.exchange_timestamp),
300 6 : GNUNET_JSON_spec_mark_optional (
301 : GNUNET_JSON_spec_timestamp ("refund_deadline",
302 : &dc.refund_deadline),
303 : NULL),
304 6 : GNUNET_JSON_spec_timestamp ("wire_deadline",
305 : &dc.wire_deadline),
306 6 : TALER_JSON_spec_amount ("total_without_fee",
307 : TAH_currency,
308 : &dc.total_without_fee),
309 6 : GNUNET_JSON_spec_array_const ("coin_pubs",
310 : &jcoin_pubs),
311 6 : GNUNET_JSON_spec_array_const ("coin_sigs",
312 : &jcoin_sigs),
313 6 : GNUNET_JSON_spec_fixed_auto ("merchant_pub",
314 : &dc.merchant),
315 6 : GNUNET_JSON_spec_fixed_auto ("exchange_sig",
316 : &dc.exchange_sig),
317 6 : GNUNET_JSON_spec_fixed_auto ("exchange_pub",
318 : &dc.exchange_pub),
319 6 : GNUNET_JSON_spec_timestamp ("ep_start",
320 : &es.ep_start),
321 6 : GNUNET_JSON_spec_timestamp ("ep_expire",
322 : &es.ep_expire),
323 6 : GNUNET_JSON_spec_timestamp ("ep_end",
324 : &es.ep_end),
325 6 : GNUNET_JSON_spec_fixed_auto ("master_sig",
326 : &es.master_sig),
327 6 : GNUNET_JSON_spec_end ()
328 : };
329 : unsigned int num_coins;
330 : json_t *json;
331 :
332 : (void) rh;
333 : (void) connection_cls;
334 : (void) upload_data;
335 : (void) upload_data_size;
336 : {
337 : enum GNUNET_GenericReturnValue res;
338 :
339 6 : res = TALER_MHD_parse_post_json (connection,
340 : connection_cls,
341 : upload_data,
342 : upload_data_size,
343 : &json);
344 6 : if (GNUNET_SYSERR == res)
345 0 : return MHD_NO;
346 6 : if ((GNUNET_NO == res) ||
347 6 : (NULL == json))
348 4 : return MHD_YES;
349 2 : res = TALER_MHD_parse_json_data (connection,
350 : json,
351 : spec);
352 2 : if (GNUNET_SYSERR == res)
353 : {
354 0 : json_decref (json);
355 0 : return MHD_NO; /* hard failure */
356 : }
357 2 : if (GNUNET_NO == res)
358 : {
359 0 : json_decref (json);
360 0 : return MHD_YES; /* failure */
361 : }
362 2 : dc.master_sig = es.master_sig;
363 : }
364 2 : num_coins = json_array_size (jcoin_sigs);
365 2 : if (num_coins != json_array_size (jcoin_pubs))
366 : {
367 0 : GNUNET_break_op (0);
368 0 : json_decref (json);
369 0 : return TALER_MHD_reply_with_ec (
370 : connection,
371 : TALER_EC_GENERIC_PARAMETER_MALFORMED,
372 : "coin_pubs.length != coin_sigs.length");
373 : }
374 2 : if (0 == num_coins)
375 : {
376 0 : GNUNET_break_op (0);
377 0 : json_decref (json);
378 0 : return TALER_MHD_reply_with_ec (
379 : connection,
380 : TALER_EC_GENERIC_PARAMETER_MALFORMED,
381 : "coin_pubs array is empty");
382 : }
383 2 : if (TALER_MAX_COINS < num_coins)
384 : {
385 0 : GNUNET_break_op (0);
386 0 : json_decref (json);
387 0 : return TALER_MHD_reply_with_ec (
388 : connection,
389 : TALER_EC_GENERIC_PARAMETER_MALFORMED,
390 : "coin_pubs array is too long");
391 : }
392 2 : {
393 2 : struct TALER_CoinSpendPublicKeyP coin_pubs[num_coins];
394 2 : struct TALER_CoinSpendSignatureP coin_sigs[num_coins];
395 : enum MHD_Result res;
396 :
397 4 : for (unsigned int i = 0; i < num_coins; i++)
398 : {
399 2 : json_t *jpub = json_array_get (jcoin_pubs,
400 : i);
401 2 : json_t *jsig = json_array_get (jcoin_sigs,
402 : i);
403 2 : const char *ps = json_string_value (jpub);
404 2 : const char *ss = json_string_value (jsig);
405 :
406 4 : if ((NULL == ps) ||
407 : (GNUNET_OK !=
408 2 : GNUNET_STRINGS_string_to_data (ps,
409 : strlen (ps),
410 2 : &coin_pubs[i],
411 : sizeof(coin_pubs[i]))))
412 : {
413 0 : GNUNET_break_op (0);
414 0 : json_decref (json);
415 0 : return TALER_MHD_reply_with_ec (
416 : connection,
417 : TALER_EC_GENERIC_PARAMETER_MALFORMED,
418 : "coin_pub[] malformed");
419 : }
420 4 : if ((NULL == ss) ||
421 : (GNUNET_OK !=
422 2 : GNUNET_STRINGS_string_to_data (ss,
423 : strlen (ss),
424 2 : &coin_sigs[i],
425 : sizeof(coin_sigs[i]))))
426 : {
427 0 : GNUNET_break_op (0);
428 0 : json_decref (json);
429 0 : return TALER_MHD_reply_with_ec (
430 : connection,
431 : TALER_EC_GENERIC_PARAMETER_MALFORMED,
432 : "coin_sig[] malformed");
433 : }
434 : }
435 2 : dc.num_coins = num_coins;
436 2 : dc.coin_pubs = coin_pubs;
437 2 : dc.coin_sigs = coin_sigs;
438 2 : es.exchange_pub = dc.exchange_pub; /* used twice! */
439 2 : res = verify_and_execute_deposit_confirmation (connection,
440 : &dc,
441 : &es);
442 2 : GNUNET_JSON_parse_free (spec);
443 2 : json_decref (json);
444 2 : return res;
445 : }
446 : }
447 :
448 :
449 : void
450 5 : TEAH_put_deposit_confirmation_init (void)
451 : {
452 5 : cache = GNUNET_CONTAINER_multihashmap_create (32,
453 : GNUNET_NO);
454 5 : GNUNET_assert (0 == pthread_mutex_init (&lock, NULL));
455 5 : }
456 :
457 :
458 : void
459 5 : TEAH_put_deposit_confirmation_done (void)
460 : {
461 5 : if (NULL != cache)
462 : {
463 5 : GNUNET_CONTAINER_multihashmap_destroy (cache);
464 5 : cache = NULL;
465 5 : GNUNET_assert (0 == pthread_mutex_destroy (&lock));
466 : }
467 5 : }
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