Line data Source code
1 : /*
2 : This file is part of TALER
3 : Copyright (C) 2022-2023 Taler Systems SA
4 :
5 : TALER is free software; you can redistribute it and/or modify it under the
6 : terms of the GNU 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 keys of the exchange this request handle will use
77 : */
78 : struct TALER_EXCHANGE_Keys *keys;
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 7 : handle_purse_deposit_finished (void *cls,
138 : long response_code,
139 : const void *response)
140 : {
141 7 : struct TALER_EXCHANGE_PurseDepositHandle *pch = cls;
142 7 : const json_t *j = response;
143 7 : struct TALER_EXCHANGE_PurseDepositResponse dr = {
144 : .hr.reply = j,
145 7 : .hr.http_status = (unsigned int) response_code
146 : };
147 7 : const struct TALER_EXCHANGE_Keys *keys = pch->keys;
148 :
149 7 : pch->job = NULL;
150 7 : switch (response_code)
151 : {
152 0 : case 0:
153 0 : dr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
154 0 : break;
155 5 : case MHD_HTTP_OK:
156 : {
157 : struct GNUNET_TIME_Timestamp etime;
158 : struct TALER_ExchangeSignatureP exchange_sig;
159 : struct TALER_ExchangePublicKeyP exchange_pub;
160 : struct GNUNET_JSON_Specification spec[] = {
161 5 : GNUNET_JSON_spec_fixed_auto ("exchange_sig",
162 : &exchange_sig),
163 5 : GNUNET_JSON_spec_fixed_auto ("exchange_pub",
164 : &exchange_pub),
165 5 : GNUNET_JSON_spec_fixed_auto ("h_contract_terms",
166 : &dr.details.ok.h_contract_terms),
167 5 : GNUNET_JSON_spec_timestamp ("exchange_timestamp",
168 : &etime),
169 5 : GNUNET_JSON_spec_timestamp ("purse_expiration",
170 : &dr.details.ok.purse_expiration),
171 5 : TALER_JSON_spec_amount ("total_deposited",
172 5 : keys->currency,
173 : &dr.details.ok.total_deposited),
174 5 : TALER_JSON_spec_amount ("purse_value_after_fees",
175 5 : keys->currency,
176 : &dr.details.ok.purse_value_after_fees),
177 5 : GNUNET_JSON_spec_end ()
178 : };
179 :
180 5 : if (GNUNET_OK !=
181 5 : GNUNET_JSON_parse (j,
182 : spec,
183 : NULL, NULL))
184 : {
185 0 : GNUNET_break_op (0);
186 0 : dr.hr.http_status = 0;
187 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
188 0 : break;
189 : }
190 5 : if (GNUNET_OK !=
191 5 : TALER_EXCHANGE_test_signing_key (keys,
192 : &exchange_pub))
193 : {
194 0 : GNUNET_break_op (0);
195 0 : dr.hr.http_status = 0;
196 0 : dr.hr.ec = TALER_EC_EXCHANGE_PURSE_DEPOSIT_EXCHANGE_SIGNATURE_INVALID;
197 0 : break;
198 : }
199 5 : if (GNUNET_OK !=
200 5 : TALER_exchange_online_purse_created_verify (
201 : etime,
202 : dr.details.ok.purse_expiration,
203 : &dr.details.ok.purse_value_after_fees,
204 : &dr.details.ok.total_deposited,
205 5 : &pch->purse_pub,
206 : &dr.details.ok.h_contract_terms,
207 : &exchange_pub,
208 : &exchange_sig))
209 : {
210 0 : GNUNET_break_op (0);
211 0 : dr.hr.http_status = 0;
212 0 : dr.hr.ec = TALER_EC_EXCHANGE_PURSE_DEPOSIT_EXCHANGE_SIGNATURE_INVALID;
213 0 : break;
214 : }
215 : }
216 5 : break;
217 0 : case MHD_HTTP_BAD_REQUEST:
218 : /* This should never happen, either us or the exchange is buggy
219 : (or API version conflict); just pass JSON reply to the application */
220 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
221 0 : break;
222 0 : case MHD_HTTP_FORBIDDEN:
223 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
224 : /* Nothing really to verify, exchange says one of the signatures is
225 : invalid; as we checked them, this should never happen, we
226 : should pass the JSON reply to the application */
227 0 : break;
228 0 : case MHD_HTTP_NOT_FOUND:
229 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
230 : /* Nothing really to verify, this should never
231 : happen, we should pass the JSON reply to the application */
232 0 : break;
233 2 : case MHD_HTTP_CONFLICT:
234 2 : dr.hr.ec = TALER_JSON_get_error_code (j);
235 2 : switch (dr.hr.ec)
236 : {
237 0 : case TALER_EC_EXCHANGE_PURSE_DEPOSIT_CONFLICTING_META_DATA:
238 : {
239 : struct TALER_CoinSpendPublicKeyP coin_pub;
240 : struct TALER_CoinSpendSignatureP coin_sig;
241 : struct TALER_DenominationHashP h_denom_pub;
242 : struct TALER_AgeCommitmentHash phac;
243 0 : bool found = false;
244 :
245 0 : if (GNUNET_OK !=
246 0 : TALER_EXCHANGE_check_purse_coin_conflict_ (
247 0 : &pch->purse_pub,
248 0 : pch->base_url,
249 : j,
250 : &h_denom_pub,
251 : &phac,
252 : &coin_pub,
253 : &coin_sig))
254 : {
255 0 : GNUNET_break_op (0);
256 0 : dr.hr.http_status = 0;
257 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
258 0 : break;
259 : }
260 0 : for (unsigned int i = 0; i<pch->num_deposits; i++)
261 : {
262 0 : struct Coin *coin = &pch->coins[i];
263 0 : if (0 != GNUNET_memcmp (&coin_pub,
264 : &coin->coin_pub))
265 0 : continue;
266 0 : if (0 !=
267 0 : GNUNET_memcmp (&coin->h_denom_pub,
268 : &h_denom_pub))
269 : {
270 0 : found = true;
271 0 : break;
272 : }
273 0 : if (0 !=
274 0 : GNUNET_memcmp (&coin->ahac,
275 : &phac))
276 : {
277 0 : found = true;
278 0 : break;
279 : }
280 0 : if (0 == GNUNET_memcmp (&coin_sig,
281 : &coin->coin_sig))
282 : {
283 : /* identical signature => not a conflict */
284 0 : continue;
285 : }
286 0 : found = true;
287 0 : break;
288 : }
289 0 : if (! found)
290 : {
291 0 : GNUNET_break_op (0);
292 0 : dr.hr.http_status = 0;
293 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
294 0 : break;
295 : }
296 : /* meta data conflict is real! */
297 0 : break;
298 : }
299 2 : case TALER_EC_EXCHANGE_GENERIC_INSUFFICIENT_FUNDS:
300 : /* Nothing to check anymore here, proof needs to be
301 : checked in the GET /coins/$COIN_PUB handler */
302 2 : break;
303 0 : case TALER_EC_EXCHANGE_GENERIC_COIN_CONFLICTING_DENOMINATION_KEY:
304 0 : break;
305 0 : default:
306 0 : GNUNET_break_op (0);
307 0 : dr.hr.http_status = 0;
308 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
309 0 : break;
310 : } /* ec switch */
311 2 : break;
312 0 : case MHD_HTTP_GONE:
313 : /* could happen if denomination was revoked or purse expired */
314 : /* Note: one might want to check /keys for revocation
315 : signature here, alas tricky in case our /keys
316 : is outdated => left to clients */
317 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
318 0 : break;
319 0 : case MHD_HTTP_INTERNAL_SERVER_ERROR:
320 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
321 : /* Server had an internal issue; we should retry, but this API
322 : leaves this to the application */
323 0 : break;
324 0 : default:
325 : /* unexpected response code */
326 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
327 0 : GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
328 : "Unexpected response code %u/%d for exchange deposit\n",
329 : (unsigned int) response_code,
330 : dr.hr.ec);
331 0 : GNUNET_break_op (0);
332 0 : break;
333 : }
334 7 : if (TALER_EC_NONE == dr.hr.ec)
335 5 : dr.hr.hint = NULL;
336 : else
337 2 : dr.hr.hint = TALER_ErrorCode_get_hint (dr.hr.ec);
338 7 : pch->cb (pch->cb_cls,
339 : &dr);
340 7 : TALER_EXCHANGE_purse_deposit_cancel (pch);
341 7 : }
342 :
343 :
344 : struct TALER_EXCHANGE_PurseDepositHandle *
345 7 : TALER_EXCHANGE_purse_deposit (
346 : struct GNUNET_CURL_Context *ctx,
347 : const char *url,
348 : struct TALER_EXCHANGE_Keys *keys,
349 : const char *purse_exchange_url,
350 : const struct TALER_PurseContractPublicKeyP *purse_pub,
351 : uint8_t min_age,
352 : unsigned int num_deposits,
353 : const struct TALER_EXCHANGE_PurseDeposit deposits[static num_deposits],
354 : TALER_EXCHANGE_PurseDepositCallback cb,
355 : void *cb_cls)
356 7 : {
357 : struct TALER_EXCHANGE_PurseDepositHandle *pch;
358 : json_t *create_obj;
359 : json_t *deposit_arr;
360 : CURL *eh;
361 : char arg_str[sizeof (pch->purse_pub) * 2 + 32];
362 :
363 : // FIXME: use purse_exchange_url for wad transfers (#7271)
364 : (void) purse_exchange_url;
365 7 : if (0 == num_deposits)
366 : {
367 0 : GNUNET_break (0);
368 0 : return NULL;
369 : }
370 7 : pch = GNUNET_new (struct TALER_EXCHANGE_PurseDepositHandle);
371 7 : pch->purse_pub = *purse_pub;
372 7 : pch->cb = cb;
373 7 : pch->cb_cls = cb_cls;
374 : {
375 : char pub_str[sizeof (pch->purse_pub) * 2];
376 : char *end;
377 :
378 7 : end = GNUNET_STRINGS_data_to_string (
379 7 : &pch->purse_pub,
380 : sizeof (pch->purse_pub),
381 : pub_str,
382 : sizeof (pub_str));
383 7 : *end = '\0';
384 7 : GNUNET_snprintf (arg_str,
385 : sizeof (arg_str),
386 : "purses/%s/deposit",
387 : pub_str);
388 : }
389 7 : pch->url = TALER_url_join (url,
390 : arg_str,
391 : NULL);
392 7 : if (NULL == pch->url)
393 : {
394 0 : GNUNET_break (0);
395 0 : GNUNET_free (pch);
396 0 : return NULL;
397 : }
398 7 : deposit_arr = json_array ();
399 7 : GNUNET_assert (NULL != deposit_arr);
400 7 : pch->base_url = GNUNET_strdup (url);
401 7 : pch->num_deposits = num_deposits;
402 7 : pch->coins = GNUNET_new_array (num_deposits,
403 : struct Coin);
404 14 : for (unsigned int i = 0; i<num_deposits; i++)
405 : {
406 7 : const struct TALER_EXCHANGE_PurseDeposit *deposit = &deposits[i];
407 7 : const struct TALER_AgeCommitmentProof *acp = deposit->age_commitment_proof;
408 7 : struct Coin *coin = &pch->coins[i];
409 : json_t *jdeposit;
410 7 : struct TALER_AgeCommitmentHash *achp = NULL;
411 : struct TALER_AgeAttestation attest;
412 7 : struct TALER_AgeAttestation *attestp = NULL;
413 :
414 7 : if (NULL != acp)
415 : {
416 0 : TALER_age_commitment_hash (&acp->commitment,
417 : &coin->ahac);
418 0 : achp = &coin->ahac;
419 0 : if (GNUNET_OK !=
420 0 : TALER_age_commitment_attest (acp,
421 : min_age,
422 : &attest))
423 : {
424 0 : GNUNET_break (0);
425 0 : json_decref (deposit_arr);
426 0 : GNUNET_free (pch->base_url);
427 0 : GNUNET_free (pch->coins);
428 0 : GNUNET_free (pch->url);
429 0 : GNUNET_free (pch);
430 0 : return NULL;
431 : }
432 0 : attestp = &attest;
433 : }
434 7 : GNUNET_CRYPTO_eddsa_key_get_public (&deposit->coin_priv.eddsa_priv,
435 : &coin->coin_pub.eddsa_pub);
436 7 : coin->h_denom_pub = deposit->h_denom_pub;
437 7 : coin->contribution = deposit->amount;
438 7 : TALER_wallet_purse_deposit_sign (
439 7 : pch->base_url,
440 7 : &pch->purse_pub,
441 : &deposit->amount,
442 7 : &coin->h_denom_pub,
443 7 : &coin->ahac,
444 : &deposit->coin_priv,
445 : &coin->coin_sig);
446 7 : jdeposit = GNUNET_JSON_PACK (
447 : GNUNET_JSON_pack_allow_null (
448 : GNUNET_JSON_pack_data_auto ("h_age_commitment",
449 : achp)),
450 : GNUNET_JSON_pack_allow_null (
451 : GNUNET_JSON_pack_data_auto ("age_attestation",
452 : attestp)),
453 : TALER_JSON_pack_amount ("amount",
454 : &deposit->amount),
455 : GNUNET_JSON_pack_data_auto ("denom_pub_hash",
456 : &deposit->h_denom_pub),
457 : TALER_JSON_pack_denom_sig ("ub_sig",
458 : &deposit->denom_sig),
459 : GNUNET_JSON_pack_data_auto ("coin_pub",
460 : &coin->coin_pub),
461 : GNUNET_JSON_pack_data_auto ("coin_sig",
462 : &coin->coin_sig));
463 7 : GNUNET_assert (0 ==
464 : json_array_append_new (deposit_arr,
465 : jdeposit));
466 : }
467 7 : create_obj = GNUNET_JSON_PACK (
468 : GNUNET_JSON_pack_array_steal ("deposits",
469 : deposit_arr));
470 7 : GNUNET_assert (NULL != create_obj);
471 7 : eh = TALER_EXCHANGE_curl_easy_get_ (pch->url);
472 14 : if ( (NULL == eh) ||
473 : (GNUNET_OK !=
474 7 : TALER_curl_easy_post (&pch->ctx,
475 : eh,
476 : create_obj)) )
477 : {
478 0 : GNUNET_break (0);
479 0 : if (NULL != eh)
480 0 : curl_easy_cleanup (eh);
481 0 : json_decref (create_obj);
482 0 : GNUNET_free (pch->base_url);
483 0 : GNUNET_free (pch->url);
484 0 : GNUNET_free (pch->coins);
485 0 : GNUNET_free (pch);
486 0 : return NULL;
487 : }
488 7 : json_decref (create_obj);
489 7 : GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
490 : "URL for purse deposit: `%s'\n",
491 : pch->url);
492 7 : pch->keys = TALER_EXCHANGE_keys_incref (keys);
493 14 : pch->job = GNUNET_CURL_job_add2 (ctx,
494 : eh,
495 7 : pch->ctx.headers,
496 : &handle_purse_deposit_finished,
497 : pch);
498 7 : return pch;
499 : }
500 :
501 :
502 : void
503 7 : TALER_EXCHANGE_purse_deposit_cancel (
504 : struct TALER_EXCHANGE_PurseDepositHandle *pch)
505 : {
506 7 : if (NULL != pch->job)
507 : {
508 0 : GNUNET_CURL_job_cancel (pch->job);
509 0 : pch->job = NULL;
510 : }
511 7 : GNUNET_free (pch->base_url);
512 7 : GNUNET_free (pch->url);
513 7 : GNUNET_free (pch->coins);
514 7 : TALER_EXCHANGE_keys_decref (pch->keys);
515 7 : TALER_curl_easy_post_finished (&pch->ctx);
516 7 : GNUNET_free (pch);
517 7 : }
518 :
519 :
520 : /* end of exchange_api_purse_deposit.c */
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