Line data Source code
1 : /*
2 : This file is part of TALER
3 : Copyright (C) 2017-2026 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_post-recoup-withdraw.c
19 : * @brief Implementation of the /recoup request of the exchange's HTTP API
20 : * @author Christian Grothoff
21 : */
22 : #include "taler/platform.h"
23 : #include <jansson.h>
24 : #include <microhttpd.h> /* just for HTTP status codes */
25 : #include <gnunet/gnunet_util_lib.h>
26 : #include <gnunet/gnunet_json_lib.h>
27 : #include <gnunet/gnunet_curl_lib.h>
28 : #include "taler/taler_json_lib.h"
29 : #include "taler/taler_exchange_service.h"
30 : #include "exchange_api_common.h"
31 : #include "exchange_api_handle.h"
32 : #include "taler/taler_signatures.h"
33 : #include "exchange_api_curl_defaults.h"
34 :
35 :
36 : /**
37 : * @brief A Recoup Handle
38 : */
39 : struct TALER_EXCHANGE_PostRecoupWithdrawHandle
40 : {
41 :
42 : /**
43 : * The base URL for this request.
44 : */
45 : char *base_url;
46 :
47 : /**
48 : * The full URL for this request, set during _start.
49 : */
50 : char *url;
51 :
52 : /**
53 : * Minor context that holds body and headers.
54 : */
55 : struct TALER_CURL_PostContext post_ctx;
56 :
57 : /**
58 : * Handle for the request.
59 : */
60 : struct GNUNET_CURL_Job *job;
61 :
62 : /**
63 : * Function to call with the result.
64 : */
65 : TALER_EXCHANGE_PostRecoupWithdrawCallback cb;
66 :
67 : /**
68 : * Closure for @a cb.
69 : */
70 : TALER_EXCHANGE_POST_RECOUP_WITHDRAW_RESULT_CLOSURE *cb_cls;
71 :
72 : /**
73 : * Reference to the execution context.
74 : */
75 : struct GNUNET_CURL_Context *ctx;
76 :
77 : /**
78 : * The keys of the exchange this request handle will use.
79 : */
80 : struct TALER_EXCHANGE_Keys *keys;
81 :
82 : /**
83 : * Public key of the coin we are trying to get paid back.
84 : */
85 : struct TALER_CoinSpendPublicKeyP coin_pub;
86 :
87 : /**
88 : * Pre-built request body.
89 : */
90 : json_t *body;
91 :
92 : };
93 :
94 :
95 : /**
96 : * Parse a recoup response. If it is valid, call the callback.
97 : *
98 : * @param ph recoup handle
99 : * @param json json reply with the signature
100 : * @return #GNUNET_OK if the signature is valid and we called the callback;
101 : * #GNUNET_SYSERR if not (callback must still be called)
102 : */
103 : static enum GNUNET_GenericReturnValue
104 0 : process_recoup_response (
105 : const struct TALER_EXCHANGE_PostRecoupWithdrawHandle *ph,
106 : const json_t *json)
107 : {
108 0 : struct TALER_EXCHANGE_PostRecoupWithdrawResponse rr = {
109 : .hr.reply = json,
110 : .hr.http_status = MHD_HTTP_OK
111 : };
112 : struct GNUNET_JSON_Specification spec_withdraw[] = {
113 0 : GNUNET_JSON_spec_fixed_auto ("reserve_pub",
114 : &rr.details.ok.reserve_pub),
115 0 : GNUNET_JSON_spec_end ()
116 : };
117 :
118 0 : if (GNUNET_OK !=
119 0 : GNUNET_JSON_parse (json,
120 : spec_withdraw,
121 : NULL, NULL))
122 : {
123 0 : GNUNET_break_op (0);
124 0 : return GNUNET_SYSERR;
125 : }
126 0 : ph->cb (ph->cb_cls,
127 : &rr);
128 0 : return GNUNET_OK;
129 : }
130 :
131 :
132 : /**
133 : * Function called when we're done processing the
134 : * HTTP /recoup request.
135 : *
136 : * @param cls the `struct TALER_EXCHANGE_PostRecoupWithdrawHandle`
137 : * @param response_code HTTP response code, 0 on error
138 : * @param response parsed JSON result, NULL on error
139 : */
140 : static void
141 0 : handle_recoup_finished (void *cls,
142 : long response_code,
143 : const void *response)
144 : {
145 0 : struct TALER_EXCHANGE_PostRecoupWithdrawHandle *ph = cls;
146 0 : const json_t *j = response;
147 0 : struct TALER_EXCHANGE_PostRecoupWithdrawResponse rr = {
148 : .hr.reply = j,
149 0 : .hr.http_status = (unsigned int) response_code
150 : };
151 :
152 0 : ph->job = NULL;
153 0 : switch (response_code)
154 : {
155 0 : case 0:
156 0 : rr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
157 0 : break;
158 0 : case MHD_HTTP_OK:
159 0 : if (GNUNET_OK !=
160 0 : process_recoup_response (ph,
161 : j))
162 : {
163 0 : GNUNET_break_op (0);
164 0 : rr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
165 0 : rr.hr.http_status = 0;
166 0 : break;
167 : }
168 0 : TALER_EXCHANGE_post_recoup_withdraw_cancel (ph);
169 0 : return;
170 0 : case MHD_HTTP_BAD_REQUEST:
171 : /* This should never happen, either us or the exchange is buggy
172 : (or API version conflict); just pass JSON reply to the application */
173 0 : rr.hr.ec = TALER_JSON_get_error_code (j);
174 0 : rr.hr.hint = TALER_JSON_get_error_hint (j);
175 0 : break;
176 0 : case MHD_HTTP_CONFLICT:
177 : {
178 : struct TALER_Amount min_key;
179 :
180 0 : rr.hr.ec = TALER_JSON_get_error_code (j);
181 0 : rr.hr.hint = TALER_JSON_get_error_hint (j);
182 0 : if (GNUNET_OK !=
183 0 : TALER_EXCHANGE_get_min_denomination_ (ph->keys,
184 : &min_key))
185 : {
186 0 : GNUNET_break (0);
187 0 : rr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
188 0 : rr.hr.http_status = 0;
189 0 : break;
190 : }
191 0 : break;
192 : }
193 0 : case MHD_HTTP_FORBIDDEN:
194 : /* Nothing really to verify, exchange says one of the signatures is
195 : invalid; as we checked them, this should never happen, we
196 : should pass the JSON reply to the application */
197 0 : rr.hr.ec = TALER_JSON_get_error_code (j);
198 0 : rr.hr.hint = TALER_JSON_get_error_hint (j);
199 0 : break;
200 0 : case MHD_HTTP_NOT_FOUND:
201 : /* Nothing really to verify, this should never
202 : happen, we should pass the JSON reply to the application */
203 0 : rr.hr.ec = TALER_JSON_get_error_code (j);
204 0 : rr.hr.hint = TALER_JSON_get_error_hint (j);
205 0 : break;
206 0 : case MHD_HTTP_GONE:
207 : /* Kind of normal: the money was already sent to the merchant
208 : (it was too late for the refund). */
209 0 : rr.hr.ec = TALER_JSON_get_error_code (j);
210 0 : rr.hr.hint = TALER_JSON_get_error_hint (j);
211 0 : break;
212 0 : case MHD_HTTP_INTERNAL_SERVER_ERROR:
213 : /* Server had an internal issue; we should retry, but this API
214 : leaves this to the application */
215 0 : rr.hr.ec = TALER_JSON_get_error_code (j);
216 0 : rr.hr.hint = TALER_JSON_get_error_hint (j);
217 0 : break;
218 0 : default:
219 : /* unexpected response code */
220 0 : rr.hr.ec = TALER_JSON_get_error_code (j);
221 0 : rr.hr.hint = TALER_JSON_get_error_hint (j);
222 0 : GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
223 : "Unexpected response code %u/%d for exchange recoup\n",
224 : (unsigned int) response_code,
225 : (int) rr.hr.ec);
226 0 : GNUNET_break (0);
227 0 : break;
228 : }
229 0 : ph->cb (ph->cb_cls,
230 : &rr);
231 0 : TALER_EXCHANGE_post_recoup_withdraw_cancel (ph);
232 : }
233 :
234 :
235 : struct TALER_EXCHANGE_PostRecoupWithdrawHandle *
236 0 : TALER_EXCHANGE_post_recoup_withdraw_create (
237 : struct GNUNET_CURL_Context *ctx,
238 : const char *url,
239 : struct TALER_EXCHANGE_Keys *keys,
240 : const struct TALER_EXCHANGE_DenomPublicKey *pk,
241 : const struct TALER_DenominationSignature *denom_sig,
242 : const struct TALER_ExchangeBlindingValues *exchange_vals,
243 : const struct TALER_PlanchetMasterSecretP *ps,
244 : const struct TALER_HashBlindedPlanchetsP *h_planchets)
245 : {
246 : struct TALER_EXCHANGE_PostRecoupWithdrawHandle *ph;
247 : struct TALER_DenominationHashP h_denom_pub;
248 : struct TALER_CoinSpendPrivateKeyP coin_priv;
249 : union GNUNET_CRYPTO_BlindingSecretP bks;
250 : struct TALER_CoinSpendSignatureP coin_sig;
251 :
252 0 : ph = GNUNET_new (struct TALER_EXCHANGE_PostRecoupWithdrawHandle);
253 0 : ph->ctx = ctx;
254 0 : ph->base_url = GNUNET_strdup (url);
255 0 : ph->keys = TALER_EXCHANGE_keys_incref (keys);
256 0 : TALER_planchet_setup_coin_priv (ps,
257 : exchange_vals,
258 : &coin_priv);
259 0 : TALER_planchet_blinding_secret_create (ps,
260 : exchange_vals,
261 : &bks);
262 0 : GNUNET_CRYPTO_eddsa_key_get_public (&coin_priv.eddsa_priv,
263 : &ph->coin_pub.eddsa_pub);
264 0 : TALER_denom_pub_hash (&pk->key,
265 : &h_denom_pub);
266 0 : TALER_wallet_recoup_sign (&h_denom_pub,
267 : &bks,
268 : &coin_priv,
269 : &coin_sig);
270 0 : ph->body = GNUNET_JSON_PACK (
271 : GNUNET_JSON_pack_data_auto ("denom_pub_hash",
272 : &h_denom_pub),
273 : TALER_JSON_pack_denom_sig ("denom_sig",
274 : denom_sig),
275 : TALER_JSON_pack_exchange_blinding_values ("ewv",
276 : exchange_vals),
277 : GNUNET_JSON_pack_data_auto ("coin_sig",
278 : &coin_sig),
279 : GNUNET_JSON_pack_data_auto ("h_planchets",
280 : h_planchets),
281 : GNUNET_JSON_pack_data_auto ("coin_blind_key_secret",
282 : &bks));
283 0 : switch (denom_sig->unblinded_sig->cipher)
284 : {
285 0 : case GNUNET_CRYPTO_BSA_INVALID:
286 0 : json_decref (ph->body);
287 0 : GNUNET_free (ph->base_url);
288 0 : TALER_EXCHANGE_keys_decref (ph->keys);
289 0 : GNUNET_free (ph);
290 0 : GNUNET_break (0);
291 0 : return NULL;
292 0 : case GNUNET_CRYPTO_BSA_RSA:
293 0 : break;
294 0 : case GNUNET_CRYPTO_BSA_CS:
295 : {
296 : union GNUNET_CRYPTO_BlindSessionNonce nonce;
297 :
298 : /* NOTE: this is not elegant, and as per the note in TALER_coin_ev_hash()
299 : it is not strictly clear that the nonce is needed. Best case would be
300 : to find a way to include it more 'naturally' somehow, for example with
301 : the variant union version of bks! */
302 0 : TALER_cs_withdraw_nonce_derive (ps,
303 : &nonce.cs_nonce);
304 0 : GNUNET_assert (
305 : 0 ==
306 : json_object_set_new (ph->body,
307 : "nonce",
308 : GNUNET_JSON_from_data_auto (
309 : &nonce)));
310 : }
311 0 : break;
312 : }
313 0 : return ph;
314 : }
315 :
316 :
317 : enum TALER_ErrorCode
318 0 : TALER_EXCHANGE_post_recoup_withdraw_start (
319 : struct TALER_EXCHANGE_PostRecoupWithdrawHandle *ph,
320 : TALER_EXCHANGE_PostRecoupWithdrawCallback cb,
321 : TALER_EXCHANGE_POST_RECOUP_WITHDRAW_RESULT_CLOSURE *cb_cls)
322 : {
323 : CURL *eh;
324 : char arg_str[sizeof (struct TALER_CoinSpendPublicKeyP) * 2 + 32];
325 :
326 0 : ph->cb = cb;
327 0 : ph->cb_cls = cb_cls;
328 : {
329 : char pub_str[sizeof (struct TALER_CoinSpendPublicKeyP) * 2];
330 : char *end;
331 :
332 0 : end = GNUNET_STRINGS_data_to_string (
333 0 : &ph->coin_pub,
334 : sizeof (struct TALER_CoinSpendPublicKeyP),
335 : pub_str,
336 : sizeof (pub_str));
337 0 : *end = '\0';
338 0 : GNUNET_snprintf (arg_str,
339 : sizeof (arg_str),
340 : "coins/%s/recoup",
341 : pub_str);
342 : }
343 0 : ph->url = TALER_url_join (ph->base_url,
344 : arg_str,
345 : NULL);
346 0 : if (NULL == ph->url)
347 : {
348 0 : GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
349 : "Could not construct request URL.\n");
350 0 : return TALER_EC_GENERIC_CONFIGURATION_INVALID;
351 : }
352 0 : GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
353 : "URL for recoup: `%s'\n",
354 : ph->url);
355 0 : eh = TALER_EXCHANGE_curl_easy_get_ (ph->url);
356 0 : if ( (NULL == eh) ||
357 : (GNUNET_OK !=
358 0 : TALER_curl_easy_post (&ph->post_ctx,
359 : eh,
360 0 : ph->body)) )
361 : {
362 0 : GNUNET_break (0);
363 0 : if (NULL != eh)
364 0 : curl_easy_cleanup (eh);
365 0 : return TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE;
366 : }
367 0 : ph->job = GNUNET_CURL_job_add2 (ph->ctx,
368 : eh,
369 0 : ph->post_ctx.headers,
370 : &handle_recoup_finished,
371 : ph);
372 0 : if (NULL == ph->job)
373 0 : return TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE;
374 0 : return TALER_EC_NONE;
375 : }
376 :
377 :
378 : void
379 0 : TALER_EXCHANGE_post_recoup_withdraw_cancel (
380 : struct TALER_EXCHANGE_PostRecoupWithdrawHandle *ph)
381 : {
382 0 : if (NULL != ph->job)
383 : {
384 0 : GNUNET_CURL_job_cancel (ph->job);
385 0 : ph->job = NULL;
386 : }
387 0 : TALER_curl_easy_post_finished (&ph->post_ctx);
388 0 : GNUNET_free (ph->url);
389 0 : GNUNET_free (ph->base_url);
390 0 : json_decref (ph->body);
391 0 : TALER_EXCHANGE_keys_decref (ph->keys);
392 0 : GNUNET_free (ph);
393 0 : }
394 :
395 :
396 : /* end of exchange_api_post-recoup-withdraw.c */
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