Line data Source code
1 : /*
2 : This file is part of TALER
3 : Copyright (C) 2022 Taler Systems SA
4 :
5 : TALER is free software; you can redistribute it and/or modify it under the
6 : terms of the GNU 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 General Public License for more details.
12 :
13 : You should have received a copy of the GNU General Public License along with
14 : TALER; see the file COPYING. If not, see
15 : <http://www.gnu.org/licenses/>
16 : */
17 : /**
18 : * @file lib/exchange_api_purse_deposit.c
19 : * @brief Implementation of the client to create a purse with
20 : * an initial set of deposits (and a contract)
21 : * @author Christian Grothoff
22 : */
23 : #include "platform.h"
24 : #include <jansson.h>
25 : #include <microhttpd.h> /* just for HTTP status codes */
26 : #include <gnunet/gnunet_util_lib.h>
27 : #include <gnunet/gnunet_json_lib.h>
28 : #include <gnunet/gnunet_curl_lib.h>
29 : #include "taler_json_lib.h"
30 : #include "taler_exchange_service.h"
31 : #include "exchange_api_common.h"
32 : #include "exchange_api_handle.h"
33 : #include "taler_signatures.h"
34 : #include "exchange_api_curl_defaults.h"
35 :
36 :
37 : /**
38 : * Information we track per coin.
39 : */
40 : struct Coin
41 : {
42 : /**
43 : * Coin's public key.
44 : */
45 : struct TALER_CoinSpendPublicKeyP coin_pub;
46 :
47 : /**
48 : * Signature made with the coin.
49 : */
50 : struct TALER_CoinSpendSignatureP coin_sig;
51 :
52 : /**
53 : * Coin's denomination.
54 : */
55 : struct TALER_DenominationHashP h_denom_pub;
56 :
57 : /**
58 : * Age restriction hash for the coin.
59 : */
60 : struct TALER_AgeCommitmentHash ahac;
61 :
62 : /**
63 : * How much did we say the coin contributed.
64 : */
65 : struct TALER_Amount contribution;
66 : };
67 :
68 :
69 : /**
70 : * @brief A purse create with deposit handle
71 : */
72 : struct TALER_EXCHANGE_PurseDepositHandle
73 : {
74 :
75 : /**
76 : * The connection to exchange this request handle will use
77 : */
78 : struct TALER_EXCHANGE_Handle *exchange;
79 :
80 : /**
81 : * The url for this request.
82 : */
83 : char *url;
84 :
85 : /**
86 : * The base url of the exchange we are talking to.
87 : */
88 : char *base_url;
89 :
90 : /**
91 : * Context for #TEH_curl_easy_post(). Keeps the data that must
92 : * persist for Curl to make the upload.
93 : */
94 : struct TALER_CURL_PostContext ctx;
95 :
96 : /**
97 : * Handle for the request.
98 : */
99 : struct GNUNET_CURL_Job *job;
100 :
101 : /**
102 : * Function to call with the result.
103 : */
104 : TALER_EXCHANGE_PurseDepositCallback cb;
105 :
106 : /**
107 : * Closure for @a cb.
108 : */
109 : void *cb_cls;
110 :
111 : /**
112 : * Public key of the purse.
113 : */
114 : struct TALER_PurseContractPublicKeyP purse_pub;
115 :
116 : /**
117 : * Array of @e num_deposits coins we are depositing.
118 : */
119 : struct Coin *coins;
120 :
121 : /**
122 : * Number of coins we are depositing.
123 : */
124 : unsigned int num_deposits;
125 : };
126 :
127 :
128 : /**
129 : * Function called when we're done processing the
130 : * HTTP /purses/$PID/deposit request.
131 : *
132 : * @param cls the `struct TALER_EXCHANGE_PurseDepositHandle`
133 : * @param response_code HTTP response code, 0 on error
134 : * @param response parsed JSON result, NULL on error
135 : */
136 : static void
137 0 : handle_purse_deposit_finished (void *cls,
138 : long response_code,
139 : const void *response)
140 : {
141 0 : struct TALER_EXCHANGE_PurseDepositHandle *pch = cls;
142 0 : const json_t *j = response;
143 0 : struct TALER_EXCHANGE_PurseDepositResponse dr = {
144 : .hr.reply = j,
145 0 : .hr.http_status = (unsigned int) response_code
146 : };
147 : const struct TALER_EXCHANGE_Keys *keys;
148 :
149 0 : pch->job = NULL;
150 0 : keys = TALER_EXCHANGE_get_keys (pch->exchange);
151 0 : switch (response_code)
152 : {
153 0 : case 0:
154 0 : dr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
155 0 : break;
156 0 : case MHD_HTTP_OK:
157 : {
158 : struct GNUNET_TIME_Timestamp etime;
159 : struct TALER_ExchangeSignatureP exchange_sig;
160 : struct TALER_ExchangePublicKeyP exchange_pub;
161 : struct GNUNET_JSON_Specification spec[] = {
162 0 : GNUNET_JSON_spec_fixed_auto ("exchange_sig",
163 : &exchange_sig),
164 0 : GNUNET_JSON_spec_fixed_auto ("exchange_pub",
165 : &exchange_pub),
166 0 : GNUNET_JSON_spec_fixed_auto ("h_contract_terms",
167 : &dr.details.success.h_contract_terms),
168 0 : GNUNET_JSON_spec_timestamp ("exchange_timestamp",
169 : &etime),
170 0 : GNUNET_JSON_spec_timestamp ("purse_expiration",
171 : &dr.details.success.purse_expiration),
172 0 : TALER_JSON_spec_amount ("total_deposited",
173 0 : keys->currency,
174 : &dr.details.success.total_deposited),
175 0 : TALER_JSON_spec_amount ("purse_value_after_fees",
176 0 : keys->currency,
177 : &dr.details.success.purse_value_after_fees),
178 0 : GNUNET_JSON_spec_end ()
179 : };
180 :
181 0 : if (GNUNET_OK !=
182 0 : GNUNET_JSON_parse (j,
183 : spec,
184 : NULL, NULL))
185 : {
186 0 : GNUNET_break_op (0);
187 0 : dr.hr.http_status = 0;
188 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
189 0 : break;
190 : }
191 0 : if (GNUNET_OK !=
192 0 : TALER_EXCHANGE_test_signing_key (keys,
193 : &exchange_pub))
194 : {
195 0 : GNUNET_break_op (0);
196 0 : dr.hr.http_status = 0;
197 0 : dr.hr.ec = TALER_EC_EXCHANGE_PURSE_DEPOSIT_EXCHANGE_SIGNATURE_INVALID;
198 0 : break;
199 : }
200 0 : if (GNUNET_OK !=
201 0 : TALER_exchange_online_purse_created_verify (
202 : etime,
203 : dr.details.success.purse_expiration,
204 : &dr.details.success.purse_value_after_fees,
205 : &dr.details.success.total_deposited,
206 0 : &pch->purse_pub,
207 : &dr.details.success.h_contract_terms,
208 : &exchange_pub,
209 : &exchange_sig))
210 : {
211 0 : GNUNET_break_op (0);
212 0 : dr.hr.http_status = 0;
213 0 : dr.hr.ec = TALER_EC_EXCHANGE_PURSE_DEPOSIT_EXCHANGE_SIGNATURE_INVALID;
214 0 : break;
215 : }
216 : }
217 0 : break;
218 0 : case MHD_HTTP_BAD_REQUEST:
219 : /* This should never happen, either us or the exchange is buggy
220 : (or API version conflict); just pass JSON reply to the application */
221 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
222 0 : break;
223 0 : case MHD_HTTP_FORBIDDEN:
224 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
225 : /* Nothing really to verify, exchange says one of the signatures is
226 : invalid; as we checked them, this should never happen, we
227 : should pass the JSON reply to the application */
228 0 : break;
229 0 : case MHD_HTTP_NOT_FOUND:
230 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
231 : /* Nothing really to verify, this should never
232 : happen, we should pass the JSON reply to the application */
233 0 : break;
234 0 : case MHD_HTTP_CONFLICT:
235 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
236 0 : switch (dr.hr.ec)
237 : {
238 0 : case TALER_EC_EXCHANGE_PURSE_DEPOSIT_CONFLICTING_META_DATA:
239 : {
240 : struct TALER_CoinSpendPublicKeyP coin_pub;
241 : struct TALER_CoinSpendSignatureP coin_sig;
242 : struct TALER_DenominationHashP h_denom_pub;
243 : struct TALER_AgeCommitmentHash phac;
244 0 : bool found = false;
245 :
246 0 : if (GNUNET_OK !=
247 0 : TALER_EXCHANGE_check_purse_coin_conflict_ (
248 0 : &pch->purse_pub,
249 0 : pch->base_url,
250 : j,
251 : &h_denom_pub,
252 : &phac,
253 : &coin_pub,
254 : &coin_sig))
255 : {
256 0 : GNUNET_break_op (0);
257 0 : dr.hr.http_status = 0;
258 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
259 0 : break;
260 : }
261 0 : for (unsigned int i = 0; i<pch->num_deposits; i++)
262 : {
263 0 : struct Coin *coin = &pch->coins[i];
264 0 : if (0 != GNUNET_memcmp (&coin_pub,
265 : &coin->coin_pub))
266 0 : continue;
267 0 : if (0 !=
268 0 : GNUNET_memcmp (&coin->h_denom_pub,
269 : &h_denom_pub))
270 : {
271 0 : found = true;
272 0 : break;
273 : }
274 0 : if (0 !=
275 0 : GNUNET_memcmp (&coin->ahac,
276 : &phac))
277 : {
278 0 : found = true;
279 0 : break;
280 : }
281 0 : if (0 == GNUNET_memcmp (&coin_sig,
282 : &coin->coin_sig))
283 : {
284 : /* identical signature => not a conflict */
285 0 : continue;
286 : }
287 0 : found = true;
288 0 : break;
289 : }
290 0 : if (! found)
291 : {
292 0 : GNUNET_break_op (0);
293 0 : dr.hr.http_status = 0;
294 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
295 0 : break;
296 : }
297 : /* meta data conflict is real! */
298 0 : break;
299 : }
300 0 : case TALER_EC_EXCHANGE_GENERIC_INSUFFICIENT_FUNDS:
301 : {
302 : struct TALER_CoinSpendPublicKeyP coin_pub;
303 : struct TALER_Amount remaining;
304 0 : bool found = false;
305 : const struct Coin *my_coin;
306 :
307 0 : if (GNUNET_OK !=
308 0 : TALER_EXCHANGE_check_coin_amount_conflict_ (
309 : keys,
310 : j,
311 : &coin_pub,
312 : &remaining))
313 : {
314 0 : dr.hr.http_status = 0;
315 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
316 0 : break;
317 : }
318 0 : for (unsigned int i = 0; i<pch->num_deposits; i++)
319 : {
320 0 : if (0 == GNUNET_memcmp (&coin_pub,
321 : &pch->coins[i].coin_pub))
322 : {
323 0 : found = true;
324 0 : my_coin = &pch->coins[i];
325 0 : break;
326 : }
327 : }
328 0 : if (! found)
329 : {
330 : /* proof is about a coin we did not even deposit */
331 0 : GNUNET_break_op (0);
332 0 : dr.hr.http_status = 0;
333 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
334 0 : break;
335 : }
336 0 : if (1 == TALER_amount_cmp (&remaining,
337 : &my_coin->contribution))
338 : {
339 : /* transaction should have still fit */
340 0 : GNUNET_break_op (0);
341 0 : dr.hr.http_status = 0;
342 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
343 0 : break;
344 : }
345 0 : if (GNUNET_OK !=
346 0 : TALER_EXCHANGE_check_coin_signature_conflict_ (
347 : j,
348 : &my_coin->coin_sig))
349 : {
350 : /* THIS transaction must not be in the conflicting history */
351 0 : GNUNET_break_op (0);
352 0 : dr.hr.http_status = 0;
353 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
354 0 : break;
355 : }
356 : /* everything OK, proof of double-spending was provided */
357 0 : break;
358 : }
359 0 : case TALER_EC_EXCHANGE_GENERIC_COIN_CONFLICTING_DENOMINATION_KEY:
360 : {
361 : struct TALER_CoinSpendPublicKeyP coin_pub;
362 : struct TALER_Amount remaining;
363 0 : bool found = false;
364 : const struct Coin *my_coin;
365 :
366 0 : if (GNUNET_OK !=
367 0 : TALER_EXCHANGE_check_coin_amount_conflict_ (
368 : keys,
369 : j,
370 : &coin_pub,
371 : &remaining))
372 : {
373 0 : dr.hr.http_status = 0;
374 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
375 0 : break;
376 : }
377 0 : for (unsigned int i = 0; i<pch->num_deposits; i++)
378 : {
379 0 : if (0 == GNUNET_memcmp (&coin_pub,
380 : &pch->coins[i].coin_pub))
381 : {
382 0 : found = true;
383 0 : my_coin = &pch->coins[i];
384 0 : break;
385 : }
386 : }
387 0 : if (! found)
388 : {
389 : /* proof is about a coin we did not even deposit */
390 0 : GNUNET_break_op (0);
391 0 : dr.hr.http_status = 0;
392 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
393 0 : break;
394 : }
395 0 : if (GNUNET_OK !=
396 0 : TALER_EXCHANGE_check_coin_denomination_conflict_ (
397 : j,
398 : &my_coin->h_denom_pub))
399 : {
400 : /* no conflicting denomination detected */
401 0 : GNUNET_break_op (0);
402 0 : dr.hr.http_status = 0;
403 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
404 0 : break;
405 : }
406 : /* everything OK, proof of conflicting denomination was provided */
407 0 : break;
408 : }
409 0 : default:
410 0 : GNUNET_break_op (0);
411 0 : dr.hr.http_status = 0;
412 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
413 0 : break;
414 : } /* ec switch */
415 0 : break;
416 0 : case MHD_HTTP_GONE:
417 : /* could happen if denomination was revoked */
418 : /* Note: one might want to check /keys for revocation
419 : signature here, alas tricky in case our /keys
420 : is outdated => left to clients */
421 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
422 0 : break;
423 0 : case MHD_HTTP_INTERNAL_SERVER_ERROR:
424 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
425 : /* Server had an internal issue; we should retry, but this API
426 : leaves this to the application */
427 0 : break;
428 0 : default:
429 : /* unexpected response code */
430 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
431 0 : GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
432 : "Unexpected response code %u/%d for exchange deposit\n",
433 : (unsigned int) response_code,
434 : dr.hr.ec);
435 0 : GNUNET_break_op (0);
436 0 : break;
437 : }
438 0 : if (TALER_EC_NONE == dr.hr.ec)
439 0 : dr.hr.hint = NULL;
440 : else
441 0 : dr.hr.hint = TALER_ErrorCode_get_hint (dr.hr.ec);
442 0 : pch->cb (pch->cb_cls,
443 : &dr);
444 0 : TALER_EXCHANGE_purse_deposit_cancel (pch);
445 0 : }
446 :
447 :
448 : struct TALER_EXCHANGE_PurseDepositHandle *
449 0 : TALER_EXCHANGE_purse_deposit (
450 : struct TALER_EXCHANGE_Handle *exchange,
451 : const char *purse_exchange_url,
452 : const struct TALER_PurseContractPublicKeyP *purse_pub,
453 : uint8_t min_age,
454 : unsigned int num_deposits,
455 : const struct TALER_EXCHANGE_PurseDeposit *deposits,
456 : TALER_EXCHANGE_PurseDepositCallback cb,
457 : void *cb_cls)
458 : {
459 : struct TALER_EXCHANGE_PurseDepositHandle *pch;
460 : struct GNUNET_CURL_Context *ctx;
461 : json_t *create_obj;
462 : json_t *deposit_arr;
463 : CURL *eh;
464 : char arg_str[sizeof (pch->purse_pub) * 2 + 32];
465 :
466 : // FIXME: use purse_exchange_url for wad transfers (#7271)
467 : (void) purse_exchange_url;
468 0 : if (0 == num_deposits)
469 : {
470 0 : GNUNET_break (0);
471 0 : return NULL;
472 : }
473 0 : GNUNET_assert (GNUNET_YES ==
474 : TEAH_handle_is_ready (exchange));
475 0 : pch = GNUNET_new (struct TALER_EXCHANGE_PurseDepositHandle);
476 0 : pch->purse_pub = *purse_pub;
477 0 : pch->exchange = exchange;
478 0 : pch->cb = cb;
479 0 : pch->cb_cls = cb_cls;
480 : {
481 : char pub_str[sizeof (pch->purse_pub) * 2];
482 : char *end;
483 :
484 0 : end = GNUNET_STRINGS_data_to_string (
485 0 : &pch->purse_pub,
486 : sizeof (pch->purse_pub),
487 : pub_str,
488 : sizeof (pub_str));
489 0 : *end = '\0';
490 0 : GNUNET_snprintf (arg_str,
491 : sizeof (arg_str),
492 : "/purses/%s/deposit",
493 : pub_str);
494 : }
495 0 : pch->url = TEAH_path_to_url (exchange,
496 : arg_str);
497 0 : if (NULL == pch->url)
498 : {
499 0 : GNUNET_break (0);
500 0 : GNUNET_free (pch);
501 0 : return NULL;
502 : }
503 0 : deposit_arr = json_array ();
504 0 : GNUNET_assert (NULL != deposit_arr);
505 0 : pch->base_url = TEAH_path_to_url (exchange,
506 : "/");
507 0 : pch->num_deposits = num_deposits;
508 0 : pch->coins = GNUNET_new_array (num_deposits,
509 : struct Coin);
510 0 : for (unsigned int i = 0; i<num_deposits; i++)
511 : {
512 0 : const struct TALER_EXCHANGE_PurseDeposit *deposit = &deposits[i];
513 0 : const struct TALER_AgeCommitmentProof *acp = deposit->age_commitment_proof;
514 0 : struct Coin *coin = &pch->coins[i];
515 : json_t *jdeposit;
516 0 : struct TALER_AgeCommitmentHash *achp = NULL;
517 : struct TALER_AgeAttestation attest;
518 0 : struct TALER_AgeAttestation *attestp = NULL;
519 :
520 0 : if (NULL != acp)
521 : {
522 0 : TALER_age_commitment_hash (&acp->commitment,
523 : &coin->ahac);
524 0 : achp = &coin->ahac;
525 0 : if (GNUNET_OK !=
526 0 : TALER_age_commitment_attest (acp,
527 : min_age,
528 : &attest))
529 : {
530 0 : GNUNET_break (0);
531 0 : json_decref (deposit_arr);
532 0 : GNUNET_free (pch->base_url);
533 0 : GNUNET_free (pch->coins);
534 0 : GNUNET_free (pch);
535 0 : return NULL;
536 : }
537 0 : attestp = &attest;
538 : }
539 0 : GNUNET_CRYPTO_eddsa_key_get_public (&deposit->coin_priv.eddsa_priv,
540 : &coin->coin_pub.eddsa_pub);
541 0 : coin->h_denom_pub = deposit->h_denom_pub;
542 0 : coin->contribution = deposit->amount;
543 0 : TALER_wallet_purse_deposit_sign (
544 0 : pch->base_url,
545 0 : &pch->purse_pub,
546 : &deposit->amount,
547 0 : &coin->h_denom_pub,
548 0 : &coin->ahac,
549 : &deposit->coin_priv,
550 : &coin->coin_sig);
551 0 : jdeposit = GNUNET_JSON_PACK (
552 : GNUNET_JSON_pack_allow_null (
553 : GNUNET_JSON_pack_data_auto ("h_age_commitment",
554 : achp)),
555 : GNUNET_JSON_pack_allow_null (
556 : GNUNET_JSON_pack_data_auto ("age_attestation",
557 : attestp)),
558 : TALER_JSON_pack_amount ("amount",
559 : &deposit->amount),
560 : GNUNET_JSON_pack_data_auto ("denom_pub_hash",
561 : &deposit->h_denom_pub),
562 : TALER_JSON_pack_denom_sig ("ub_sig",
563 : &deposit->denom_sig),
564 : GNUNET_JSON_pack_data_auto ("coin_pub",
565 : &coin->coin_pub),
566 : GNUNET_JSON_pack_data_auto ("coin_sig",
567 : &coin->coin_sig));
568 0 : GNUNET_assert (0 ==
569 : json_array_append_new (deposit_arr,
570 : jdeposit));
571 : }
572 0 : create_obj = GNUNET_JSON_PACK (
573 : GNUNET_JSON_pack_array_steal ("deposits",
574 : deposit_arr));
575 0 : GNUNET_assert (NULL != create_obj);
576 0 : eh = TALER_EXCHANGE_curl_easy_get_ (pch->url);
577 0 : if ( (NULL == eh) ||
578 : (GNUNET_OK !=
579 0 : TALER_curl_easy_post (&pch->ctx,
580 : eh,
581 : create_obj)) )
582 : {
583 0 : GNUNET_break (0);
584 0 : if (NULL != eh)
585 0 : curl_easy_cleanup (eh);
586 0 : json_decref (create_obj);
587 0 : GNUNET_free (pch->base_url);
588 0 : GNUNET_free (pch->url);
589 0 : GNUNET_free (pch->coins);
590 0 : GNUNET_free (pch);
591 0 : return NULL;
592 : }
593 0 : json_decref (create_obj);
594 0 : GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
595 : "URL for purse deposit: `%s'\n",
596 : pch->url);
597 0 : ctx = TEAH_handle_to_context (exchange);
598 0 : pch->job = GNUNET_CURL_job_add2 (ctx,
599 : eh,
600 0 : pch->ctx.headers,
601 : &handle_purse_deposit_finished,
602 : pch);
603 0 : return pch;
604 : }
605 :
606 :
607 : void
608 0 : TALER_EXCHANGE_purse_deposit_cancel (
609 : struct TALER_EXCHANGE_PurseDepositHandle *pch)
610 : {
611 0 : if (NULL != pch->job)
612 : {
613 0 : GNUNET_CURL_job_cancel (pch->job);
614 0 : pch->job = NULL;
615 : }
616 0 : GNUNET_free (pch->base_url);
617 0 : GNUNET_free (pch->url);
618 0 : GNUNET_free (pch->coins);
619 0 : TALER_curl_easy_post_finished (&pch->ctx);
620 0 : GNUNET_free (pch);
621 0 : }
622 :
623 :
624 : /* end of exchange_api_purse_deposit.c */
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