donau

Donation authority for GNU Taler (experimental)
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donau_api_charity_get.c (7908B)


      1 /*
      2   This file is part of TALER
      3   Copyright (C) 2024, 2025 Taler Systems SA
      4 
      5   TALER is free software; you can redistribute it and/or modify it
      6   under the terms of the GNU General Public License as published
      7   by the Free Software Foundation; either version 3, or (at your
      8   option) any later version.
      9 
     10   TALER is distributed in the hope that it will be useful, but
     11   WITHOUT ANY WARRANTY; without even the implied warranty of
     12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     13   GNU General Public License for more details.
     14 
     15   You should have received a copy of the GNU General Public
     16   License along with TALER; see the file COPYING.  If not, see
     17   <http://www.gnu.org/licenses/>
     18 */
     19 
     20 /**
     21  * @file lib/donau_api_charity_get.c
     22  * @brief Implementation of the "handle" component of the donau's HTTP API
     23  * @author Lukas Matyja
     24  */
     25 #include <gnunet/gnunet_curl_lib.h>
     26 #include <taler/taler_json_lib.h>
     27 #include "donau_service.h"
     28 #include "donau_api_curl_defaults.h"
     29 #include "donau_json_lib.h"
     30 
     31 
     32 /**
     33  * Handle for a GET /charities/$CHARITY_ID request.
     34  */
     35 struct DONAU_CharityGetHandle
     36 {
     37   /**
     38    * The url for the /charities/$CHARITY_ID request.
     39    */
     40   char *url;
     41 
     42   /**
     43    * Entry for this request with the `struct GNUNET_CURL_Context`.
     44    */
     45   struct GNUNET_CURL_Job *job;
     46 
     47   /**
     48    * Function to call with the result.
     49    */
     50   DONAU_GetCharityResponseCallback cb;
     51 
     52   /**
     53    * Charity id we are querying.
     54    */
     55   unsigned long long charity_id;
     56 
     57   /**
     58    * Closure to pass to @e cb.
     59    */
     60   void *cb_cls;
     61 
     62 };
     63 
     64 /**
     65  * Decode the JSON in @a resp_obj from the /charities/$ID response
     66  * and store the data in the @a charity_data.
     67  *
     68  * @param[in] resp_obj JSON object to parse
     69  * @param[out] charity_data where to store the results we decoded
     70  * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
     71  * (malformed JSON)
     72  */
     73 static enum GNUNET_GenericReturnValue
     74 handle_charity_get_ok (const json_t *resp_obj,
     75                        struct DONAU_CharityGetHandle *cgh,
     76                        struct DONAU_GetCharityResponse *gcresp)
     77 {
     78   struct DONAU_Charity *charity = &gcresp->details.ok.charity;
     79   struct GNUNET_JSON_Specification spec[] = {
     80     GNUNET_JSON_spec_fixed_auto ("charity_pub",
     81                                  &charity->charity_pub),
     82     GNUNET_JSON_spec_string ("name",
     83                              &charity->name),
     84     GNUNET_JSON_spec_string ("url",
     85                              &charity->charity_url),
     86     TALER_JSON_spec_amount_any ("max_per_year",
     87                                 &charity->max_per_year),
     88     TALER_JSON_spec_amount_any ("receipts_to_date",
     89                                 &charity->receipts_to_date),
     90     GNUNET_JSON_spec_uint64 ("current_year",
     91                              &charity->current_year),
     92     GNUNET_JSON_spec_end ()
     93   };
     94 
     95   if (GNUNET_OK !=
     96       GNUNET_JSON_parse (resp_obj,
     97                          spec,
     98                          NULL,
     99                          NULL))
    100   {
    101     GNUNET_break_op (0);
    102     return GNUNET_SYSERR;
    103   }
    104   cgh->cb (cgh->cb_cls,
    105            gcresp);
    106   cgh->cb = NULL;
    107   return GNUNET_OK;
    108 }
    109 
    110 
    111 /**
    112  * Callback used when downloading the reply to a /charity request
    113  * is complete.
    114  *
    115  * @param cls the `struct KeysRequest`
    116  * @param response_code HTTP response code, 0 on error
    117  * @param resp_obj parsed JSON result, NULL on error
    118  */
    119 static void
    120 handle_charity_get_finished (void *cls,
    121                              long response_code,
    122                              const void *resp_obj)
    123 {
    124   struct DONAU_CharityGetHandle *cgh = cls;
    125   const json_t *j = resp_obj;
    126   struct DONAU_GetCharityResponse gcresp = {
    127     .hr.reply = j,
    128     .hr.http_status = (unsigned int) response_code
    129   };
    130 
    131   cgh->job = NULL;
    132   switch (response_code)
    133   {
    134   case 0:
    135     gcresp.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
    136     break;
    137   case MHD_HTTP_OK:
    138     if (GNUNET_OK !=
    139         handle_charity_get_ok (j,
    140                                cgh,
    141                                &gcresp))
    142     {
    143       gcresp.hr.http_status = 0;
    144       gcresp.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
    145     }
    146     break;
    147   case MHD_HTTP_BAD_REQUEST:
    148     /* This should never happen, either us or the donau is buggy
    149        (or API version conflict); just pass JSON reply to the application */
    150     gcresp.hr.ec = TALER_JSON_get_error_code (j);
    151     gcresp.hr.hint = TALER_JSON_get_error_hint (j);
    152     break;
    153   case MHD_HTTP_FORBIDDEN:
    154     /* Nothing really to verify */
    155     gcresp.hr.ec = TALER_JSON_get_error_code (j);
    156     gcresp.hr.hint = TALER_JSON_get_error_hint (j);
    157     break;
    158   case MHD_HTTP_NOT_FOUND:
    159     /* Nothing really to verify, this should never
    160        happen, we should pass the JSON reply to the application */
    161     gcresp.hr.ec = TALER_JSON_get_error_code (j);
    162     gcresp.hr.hint = TALER_JSON_get_error_hint (j);
    163     break;
    164   case MHD_HTTP_INTERNAL_SERVER_ERROR:
    165     /* Server had an internal issue; we should retry, but this API
    166        leaves this to the application */
    167     gcresp.hr.ec = TALER_JSON_get_error_code (j);
    168     gcresp.hr.hint = TALER_JSON_get_error_hint (j);
    169     break;
    170   default:
    171     /* unexpected response code */
    172     GNUNET_break_op (0);
    173     gcresp.hr.ec = TALER_JSON_get_error_code (j);
    174     gcresp.hr.hint = TALER_JSON_get_error_hint (j);
    175     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
    176                 "Unexpected response code %u/%d for GET %s\n",
    177                 (unsigned int) response_code,
    178                 (int) gcresp.hr.ec,
    179                 cgh->url);
    180     break;
    181   }
    182   if (NULL != cgh->cb)
    183   {
    184     cgh->cb (cgh->cb_cls,
    185              &gcresp);
    186     cgh->cb = NULL;
    187   }
    188   DONAU_charity_get_cancel (cgh);
    189 }
    190 
    191 
    192 struct DONAU_CharityGetHandle *
    193 DONAU_charity_get (
    194   struct GNUNET_CURL_Context *ctx,
    195   const char *url,
    196   const uint64_t id,
    197   const struct DONAU_CharityPrivateKeyP *charity_priv,
    198   DONAU_GetCharityResponseCallback cb,
    199   void *cb_cls)
    200 {
    201   struct DONAU_CharityGetHandle *cgh;
    202   CURL *eh;
    203   char arg_str[sizeof (id) * 2 + 32];
    204 
    205   TALER_LOG_DEBUG ("Connecting to the donau (%s)\n",
    206                    url);
    207   cgh = GNUNET_new (struct DONAU_CharityGetHandle);
    208   cgh->cb = cb;
    209   cgh->charity_id = id;
    210   cgh->cb_cls = cb_cls;
    211   GNUNET_snprintf (arg_str,
    212                    sizeof (arg_str),
    213                    "charity/%llu",
    214                    (unsigned long long)
    215                    id);
    216   cgh->url = TALER_url_join (url,
    217                              arg_str,
    218                              NULL);
    219   if (NULL == cgh->url)
    220   {
    221     GNUNET_free (cgh);
    222     return NULL;
    223   }
    224   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
    225               "Requesting a charity with URL `%s'.\n",
    226               cgh->url);
    227   eh = DONAU_curl_easy_get_ (cgh->url);
    228   if (NULL == eh)
    229   {
    230     GNUNET_break (0);
    231     GNUNET_free (cgh->url);
    232     GNUNET_free (cgh);
    233     return NULL;
    234   }
    235   cgh->job = GNUNET_CURL_job_add_with_ct_json (ctx,
    236                                                eh,
    237                                                &handle_charity_get_finished,
    238                                                cgh);
    239   GNUNET_assert (NULL != cgh->job);
    240   {
    241     struct DONAU_CharitySignatureP charity_sig;
    242     char *sig_hdr;
    243     char *hdr;
    244     struct curl_slist *auth;
    245 
    246     DONAU_charity_get_info_sign (charity_priv,
    247                                  &charity_sig);
    248 
    249     sig_hdr = GNUNET_STRINGS_data_to_string_alloc (
    250       &charity_sig,
    251       sizeof (charity_sig));
    252     GNUNET_asprintf (&hdr,
    253                      "%s: %s",
    254                      DONAU_HTTP_HEADER_CHARITY_SIGNATURE,
    255                      sig_hdr);
    256     GNUNET_free (sig_hdr);
    257     auth = curl_slist_append (NULL,
    258                               hdr);
    259     GNUNET_free (hdr);
    260     GNUNET_CURL_extend_headers (cgh->job,
    261                                 auth);
    262     curl_slist_free_all (auth);
    263   }
    264 
    265   return cgh;
    266 }
    267 
    268 
    269 void
    270 DONAU_charity_get_cancel (
    271   struct DONAU_CharityGetHandle *cgh)
    272 {
    273   if (NULL != cgh->job)
    274   {
    275     GNUNET_CURL_job_cancel (cgh->job);
    276     cgh->job = NULL;
    277   }
    278   GNUNET_free (cgh->url);
    279   GNUNET_free (cgh);
    280 }