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