Line data Source code
1 : /*
2 : This file is part of TALER
3 : Copyright (C) 2022-2026 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_get-contracts-CONTRACT_PUB.c
19 : * @brief Implementation of the GET /contracts/$CONTRACT_PUB request
20 : * @author Christian Grothoff
21 : */
22 : #include "taler/platform.h"
23 : #include <jansson.h>
24 : #include <microhttpd.h> /* just for HTTP status codes */
25 : #include <gnunet/gnunet_util_lib.h>
26 : #include <gnunet/gnunet_json_lib.h>
27 : #include <gnunet/gnunet_curl_lib.h>
28 : #include "taler/taler_json_lib.h"
29 : #include "taler/taler_exchange_service.h"
30 : #include "exchange_api_handle.h"
31 : #include "taler/taler_signatures.h"
32 : #include "exchange_api_curl_defaults.h"
33 :
34 :
35 : /**
36 : * @brief A GET /contracts/$CONTRACT_PUB Handle
37 : */
38 : struct TALER_EXCHANGE_GetContractsHandle
39 : {
40 :
41 : /**
42 : * Base URL of the exchange.
43 : */
44 : char *base_url;
45 :
46 : /**
47 : * The url for this request.
48 : */
49 : char *url;
50 :
51 : /**
52 : * Handle for the request.
53 : */
54 : struct GNUNET_CURL_Job *job;
55 :
56 : /**
57 : * Function to call with the result.
58 : */
59 : TALER_EXCHANGE_GetContractsCallback cb;
60 :
61 : /**
62 : * Closure for @e cb.
63 : */
64 : TALER_EXCHANGE_GET_CONTRACTS_RESULT_CLOSURE *cb_cls;
65 :
66 : /**
67 : * CURL context to use.
68 : */
69 : struct GNUNET_CURL_Context *ctx;
70 :
71 : /**
72 : * Private key needed to decrypt the contract.
73 : */
74 : struct TALER_ContractDiffiePrivateP contract_priv;
75 :
76 : /**
77 : * Public key matching @e contract_priv.
78 : */
79 : struct TALER_ContractDiffiePublicP cpub;
80 :
81 : };
82 :
83 :
84 : /**
85 : * Function called when we're done processing the
86 : * HTTP GET /contracts/$CONTRACT_PUB request.
87 : *
88 : * @param cls the `struct TALER_EXCHANGE_GetContractsHandle`
89 : * @param response_code HTTP response code, 0 on error
90 : * @param response parsed JSON result, NULL on error
91 : */
92 : static void
93 6 : handle_contract_get_finished (void *cls,
94 : long response_code,
95 : const void *response)
96 : {
97 6 : struct TALER_EXCHANGE_GetContractsHandle *gch = cls;
98 6 : const json_t *j = response;
99 6 : struct TALER_EXCHANGE_GetContractsResponse dr = {
100 : .hr.reply = j,
101 6 : .hr.http_status = (unsigned int) response_code
102 : };
103 :
104 6 : gch->job = NULL;
105 6 : switch (response_code)
106 : {
107 0 : case 0:
108 0 : dr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
109 0 : break;
110 6 : case MHD_HTTP_OK:
111 : {
112 : void *econtract;
113 : size_t econtract_size;
114 : struct TALER_PurseContractSignatureP econtract_sig;
115 : struct GNUNET_JSON_Specification spec[] = {
116 6 : GNUNET_JSON_spec_fixed_auto ("purse_pub",
117 : &dr.details.ok.purse_pub),
118 6 : GNUNET_JSON_spec_fixed_auto ("econtract_sig",
119 : &econtract_sig),
120 6 : GNUNET_JSON_spec_varsize ("econtract",
121 : &econtract,
122 : &econtract_size),
123 6 : GNUNET_JSON_spec_end ()
124 : };
125 :
126 6 : if (GNUNET_OK !=
127 6 : GNUNET_JSON_parse (j,
128 : spec,
129 : NULL, NULL))
130 : {
131 0 : GNUNET_break_op (0);
132 0 : dr.hr.http_status = 0;
133 0 : dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
134 0 : break;
135 : }
136 6 : if (GNUNET_OK !=
137 6 : TALER_wallet_econtract_upload_verify (
138 : econtract,
139 : econtract_size,
140 6 : &gch->cpub,
141 : &dr.details.ok.purse_pub,
142 : &econtract_sig))
143 : {
144 0 : GNUNET_break (0);
145 0 : dr.hr.http_status = 0;
146 0 : dr.hr.ec = TALER_EC_EXCHANGE_CONTRACTS_SIGNATURE_INVALID;
147 0 : GNUNET_JSON_parse_free (spec);
148 0 : break;
149 : }
150 6 : dr.details.ok.econtract = econtract;
151 6 : dr.details.ok.econtract_size = econtract_size;
152 6 : gch->cb (gch->cb_cls,
153 : &dr);
154 6 : gch->cb = NULL;
155 6 : GNUNET_JSON_parse_free (spec);
156 6 : TALER_EXCHANGE_get_contracts_cancel (gch);
157 6 : return;
158 : }
159 0 : case MHD_HTTP_BAD_REQUEST:
160 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
161 0 : dr.hr.hint = TALER_JSON_get_error_hint (j);
162 : /* This should never happen, either us or the exchange is buggy
163 : (or API version conflict); just pass JSON reply to the application */
164 0 : break;
165 0 : case MHD_HTTP_FORBIDDEN:
166 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
167 0 : dr.hr.hint = TALER_JSON_get_error_hint (j);
168 : /* Nothing really to verify, exchange says one of the signatures is
169 : invalid; as we checked them, this should never happen, we
170 : should pass the JSON reply to the application */
171 0 : break;
172 0 : case MHD_HTTP_NOT_FOUND:
173 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
174 0 : dr.hr.hint = TALER_JSON_get_error_hint (j);
175 : /* Exchange does not know about transaction;
176 : we should pass the reply to the application */
177 0 : break;
178 0 : case MHD_HTTP_INTERNAL_SERVER_ERROR:
179 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
180 0 : dr.hr.hint = TALER_JSON_get_error_hint (j);
181 : /* Server had an internal issue; we should retry, but this API
182 : leaves this to the application */
183 0 : break;
184 0 : default:
185 : /* unexpected response code */
186 0 : dr.hr.ec = TALER_JSON_get_error_code (j);
187 0 : dr.hr.hint = TALER_JSON_get_error_hint (j);
188 0 : GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
189 : "Unexpected response code %u/%d for exchange GET contracts\n",
190 : (unsigned int) response_code,
191 : (int) dr.hr.ec);
192 0 : GNUNET_break_op (0);
193 0 : break;
194 : }
195 0 : if (NULL != gch->cb)
196 0 : gch->cb (gch->cb_cls,
197 : &dr);
198 0 : TALER_EXCHANGE_get_contracts_cancel (gch);
199 : }
200 :
201 :
202 : struct TALER_EXCHANGE_GetContractsHandle *
203 6 : TALER_EXCHANGE_get_contracts_create (
204 : struct GNUNET_CURL_Context *ctx,
205 : const char *url,
206 : const struct TALER_ContractDiffiePrivateP *contract_priv)
207 : {
208 : struct TALER_EXCHANGE_GetContractsHandle *gch;
209 :
210 6 : gch = GNUNET_new (struct TALER_EXCHANGE_GetContractsHandle);
211 6 : gch->ctx = ctx;
212 6 : gch->base_url = GNUNET_strdup (url);
213 6 : gch->contract_priv = *contract_priv;
214 6 : GNUNET_CRYPTO_ecdhe_key_get_public (&contract_priv->ecdhe_priv,
215 : &gch->cpub.ecdhe_pub);
216 6 : return gch;
217 : }
218 :
219 :
220 : enum TALER_ErrorCode
221 6 : TALER_EXCHANGE_get_contracts_start (
222 : struct TALER_EXCHANGE_GetContractsHandle *gch,
223 : TALER_EXCHANGE_GetContractsCallback cb,
224 : TALER_EXCHANGE_GET_CONTRACTS_RESULT_CLOSURE *cb_cls)
225 : {
226 : char arg_str[sizeof (gch->cpub) * 2 + 48];
227 : CURL *eh;
228 :
229 6 : if (NULL != gch->job)
230 : {
231 0 : GNUNET_break (0);
232 0 : return TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE;
233 : }
234 6 : gch->cb = cb;
235 6 : gch->cb_cls = cb_cls;
236 : {
237 : char cpub_str[sizeof (gch->cpub) * 2];
238 : char *end;
239 :
240 6 : end = GNUNET_STRINGS_data_to_string (&gch->cpub,
241 : sizeof (gch->cpub),
242 : cpub_str,
243 : sizeof (cpub_str));
244 6 : *end = '\0';
245 6 : GNUNET_snprintf (arg_str,
246 : sizeof (arg_str),
247 : "contracts/%s",
248 : cpub_str);
249 : }
250 6 : gch->url = TALER_url_join (gch->base_url,
251 : arg_str,
252 : NULL);
253 6 : if (NULL == gch->url)
254 0 : return TALER_EC_GENERIC_CONFIGURATION_INVALID;
255 6 : eh = TALER_EXCHANGE_curl_easy_get_ (gch->url);
256 6 : if (NULL == eh)
257 : {
258 0 : GNUNET_free (gch->url);
259 0 : return TALER_EC_GENERIC_CONFIGURATION_INVALID;
260 : }
261 6 : gch->job = GNUNET_CURL_job_add (gch->ctx,
262 : eh,
263 : &handle_contract_get_finished,
264 : gch);
265 6 : if (NULL == gch->job)
266 0 : return TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE;
267 6 : return TALER_EC_NONE;
268 : }
269 :
270 :
271 : void
272 6 : TALER_EXCHANGE_get_contracts_cancel (
273 : struct TALER_EXCHANGE_GetContractsHandle *gch)
274 : {
275 6 : if (NULL != gch->job)
276 : {
277 0 : GNUNET_CURL_job_cancel (gch->job);
278 0 : gch->job = NULL;
279 : }
280 6 : GNUNET_free (gch->url);
281 6 : GNUNET_free (gch->base_url);
282 6 : GNUNET_free (gch);
283 6 : }
284 :
285 :
286 : /* end of exchange_api_get-contracts-CONTRACT_PUB.c */
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