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