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