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