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Base system with REST service to issue digital coins, run by the payment service provider
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exchange_api_post-reserves-attest-RESERVE_PUB.c (11630B)


      1 /*
      2   This file is part of TALER
      3   Copyright (C) 2014-2026 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_post-reserves-attest-RESERVE_PUB.c
     19  * @brief Implementation of the POST /reserves-attest/$RESERVE_PUB requests
     20  * @author Christian Grothoff
     21  */
     22 #include "taler/platform.h"
     23 #include <jansson.h>
     24 #include <microhttpd.h> /* just for HTTP attest codes */
     25 #include <gnunet/gnunet_util_lib.h>
     26 #include <gnunet/gnunet_json_lib.h>
     27 #include <gnunet/gnunet_curl_lib.h>
     28 #include "taler/taler_exchange_service.h"
     29 #include "taler/taler_json_lib.h"
     30 #include "exchange_api_handle.h"
     31 #include "taler/taler_signatures.h"
     32 #include "exchange_api_curl_defaults.h"
     33 
     34 
     35 /**
     36  * @brief A POST /reserves-attest/$RID Handle
     37  */
     38 struct TALER_EXCHANGE_PostReservesAttestHandle
     39 {
     40 
     41   /**
     42    * Reference to the execution context.
     43    */
     44   struct GNUNET_CURL_Context *ctx;
     45 
     46   /**
     47    * Base URL of the exchange.
     48    */
     49   char *base_url;
     50 
     51   /**
     52    * The url for this request, set during _start.
     53    */
     54   char *url;
     55 
     56   /**
     57    * Context for #TEH_curl_easy_post(). Keeps the data that must
     58    * persist for Curl to make the upload.
     59    */
     60   struct TALER_CURL_PostContext post_ctx;
     61 
     62   /**
     63    * Handle for the request.
     64    */
     65   struct GNUNET_CURL_Job *job;
     66 
     67   /**
     68    * Function to call with the result.
     69    */
     70   TALER_EXCHANGE_PostReservesAttestCallback cb;
     71 
     72   /**
     73    * Closure for @a cb.
     74    */
     75   TALER_EXCHANGE_POST_RESERVES_ATTEST_RESULT_CLOSURE *cb_cls;
     76 
     77   /**
     78    * The keys of the exchange this request handle will use.
     79    */
     80   struct TALER_EXCHANGE_Keys *keys;
     81 
     82   /**
     83    * Public key of the reserve we are querying.
     84    */
     85   struct TALER_ReservePublicKeyP reserve_pub;
     86 
     87   /**
     88    * Pre-built JSON body for the request.
     89    */
     90   json_t *body;
     91 
     92 };
     93 
     94 
     95 /**
     96  * We received an #MHD_HTTP_OK attest code. Handle the JSON
     97  * response.
     98  *
     99  * @param prah handle of the request
    100  * @param j JSON response
    101  * @return #GNUNET_OK on success
    102  */
    103 static enum GNUNET_GenericReturnValue
    104 handle_reserves_attest_ok (struct TALER_EXCHANGE_PostReservesAttestHandle *prah,
    105                            const json_t *j)
    106 {
    107   struct TALER_EXCHANGE_PostReservesAttestResponse rs = {
    108     .hr.reply = j,
    109     .hr.http_status = MHD_HTTP_OK
    110   };
    111   const json_t *attributes;
    112   struct GNUNET_JSON_Specification spec[] = {
    113     GNUNET_JSON_spec_timestamp ("exchange_timestamp",
    114                                 &rs.details.ok.exchange_time),
    115     GNUNET_JSON_spec_timestamp ("expiration_time",
    116                                 &rs.details.ok.expiration_time),
    117     GNUNET_JSON_spec_fixed_auto ("exchange_sig",
    118                                  &rs.details.ok.exchange_sig),
    119     GNUNET_JSON_spec_fixed_auto ("exchange_pub",
    120                                  &rs.details.ok.exchange_pub),
    121     GNUNET_JSON_spec_object_const ("attributes",
    122                                    &attributes),
    123     GNUNET_JSON_spec_end ()
    124   };
    125 
    126   if (GNUNET_OK !=
    127       GNUNET_JSON_parse (j,
    128                          spec,
    129                          NULL,
    130                          NULL))
    131   {
    132     GNUNET_break_op (0);
    133     return GNUNET_SYSERR;
    134   }
    135   if (GNUNET_OK !=
    136       TALER_EXCHANGE_test_signing_key (prah->keys,
    137                                        &rs.details.ok.exchange_pub))
    138   {
    139     GNUNET_break_op (0);
    140     rs.hr.http_status = 0;
    141     rs.hr.ec = TALER_EC_EXCHANGE_DEPOSITS_GET_INVALID_SIGNATURE_BY_EXCHANGE;
    142     prah->cb (prah->cb_cls,
    143               &rs);
    144     prah->cb = NULL;
    145     GNUNET_JSON_parse_free (spec);
    146     return GNUNET_SYSERR;
    147   }
    148   rs.details.ok.attributes = attributes;
    149   if (GNUNET_OK !=
    150       TALER_exchange_online_reserve_attest_details_verify (
    151         rs.details.ok.exchange_time,
    152         rs.details.ok.expiration_time,
    153         &prah->reserve_pub,
    154         attributes,
    155         &rs.details.ok.exchange_pub,
    156         &rs.details.ok.exchange_sig))
    157   {
    158     GNUNET_break_op (0);
    159     GNUNET_JSON_parse_free (spec);
    160     return GNUNET_SYSERR;
    161   }
    162   prah->cb (prah->cb_cls,
    163             &rs);
    164   prah->cb = NULL;
    165   GNUNET_JSON_parse_free (spec);
    166   return GNUNET_OK;
    167 }
    168 
    169 
    170 /**
    171  * Function called when we're done processing the
    172  * HTTP /reserves-attest/$RID request.
    173  *
    174  * @param cls the `struct TALER_EXCHANGE_PostReservesAttestHandle`
    175  * @param response_code HTTP response code, 0 on error
    176  * @param response parsed JSON result, NULL on error
    177  */
    178 static void
    179 handle_reserves_attest_finished (void *cls,
    180                                  long response_code,
    181                                  const void *response)
    182 {
    183   struct TALER_EXCHANGE_PostReservesAttestHandle *prah = cls;
    184   const json_t *j = response;
    185   struct TALER_EXCHANGE_PostReservesAttestResponse rs = {
    186     .hr.reply = j,
    187     .hr.http_status = (unsigned int) response_code
    188   };
    189 
    190   prah->job = NULL;
    191   switch (response_code)
    192   {
    193   case 0:
    194     rs.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
    195     break;
    196   case MHD_HTTP_OK:
    197     if (GNUNET_OK !=
    198         handle_reserves_attest_ok (prah,
    199                                    j))
    200     {
    201       rs.hr.http_status = 0;
    202       rs.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
    203     }
    204     break;
    205   case MHD_HTTP_BAD_REQUEST:
    206     /* This should never happen, either us or the exchange is buggy
    207        (or API version conflict); just pass JSON reply to the application */
    208     GNUNET_break (0);
    209     rs.hr.ec = TALER_JSON_get_error_code (j);
    210     rs.hr.hint = TALER_JSON_get_error_hint (j);
    211     break;
    212   case MHD_HTTP_FORBIDDEN:
    213     /* This should never happen, either us or the exchange is buggy
    214        (or API version conflict); just pass JSON reply to the application */
    215     GNUNET_break (0);
    216     rs.hr.ec = TALER_JSON_get_error_code (j);
    217     rs.hr.hint = TALER_JSON_get_error_hint (j);
    218     break;
    219   case MHD_HTTP_NOT_FOUND:
    220     /* Nothing really to verify, this should never
    221        happen, we should pass the JSON reply to the application */
    222     rs.hr.ec = TALER_JSON_get_error_code (j);
    223     rs.hr.hint = TALER_JSON_get_error_hint (j);
    224     break;
    225   case MHD_HTTP_CONFLICT:
    226     /* Server doesn't have the requested attributes */
    227     rs.hr.ec = TALER_JSON_get_error_code (j);
    228     rs.hr.hint = TALER_JSON_get_error_hint (j);
    229     break;
    230   case MHD_HTTP_INTERNAL_SERVER_ERROR:
    231     /* Server had an internal issue; we should retry, but this API
    232        leaves this to the application */
    233     rs.hr.ec = TALER_JSON_get_error_code (j);
    234     rs.hr.hint = TALER_JSON_get_error_hint (j);
    235     break;
    236   default:
    237     /* unexpected response code */
    238     GNUNET_break_op (0);
    239     rs.hr.ec = TALER_JSON_get_error_code (j);
    240     rs.hr.hint = TALER_JSON_get_error_hint (j);
    241     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
    242                 "Unexpected response code %u/%d for reserves attest\n",
    243                 (unsigned int) response_code,
    244                 (int) rs.hr.ec);
    245     break;
    246   }
    247   if (NULL != prah->cb)
    248   {
    249     prah->cb (prah->cb_cls,
    250               &rs);
    251     prah->cb = NULL;
    252   }
    253   TALER_EXCHANGE_post_reserves_attest_cancel (prah);
    254 }
    255 
    256 
    257 struct TALER_EXCHANGE_PostReservesAttestHandle *
    258 TALER_EXCHANGE_post_reserves_attest_create (
    259   struct GNUNET_CURL_Context *ctx,
    260   const char *url,
    261   struct TALER_EXCHANGE_Keys *keys,
    262   const struct TALER_ReservePrivateKeyP *reserve_priv,
    263   unsigned int attributes_length,
    264   const char *attributes[const static attributes_length])
    265 {
    266   struct TALER_EXCHANGE_PostReservesAttestHandle *prah;
    267   struct TALER_ReserveSignatureP reserve_sig;
    268   json_t *details;
    269   struct GNUNET_TIME_Timestamp ts;
    270 
    271   if (0 == attributes_length)
    272   {
    273     GNUNET_break (0);
    274     return NULL;
    275   }
    276   details = json_array ();
    277   GNUNET_assert (NULL != details);
    278   for (unsigned int i = 0; i < attributes_length; i++)
    279   {
    280     GNUNET_assert (0 ==
    281                    json_array_append_new (details,
    282                                           json_string (attributes[i])));
    283   }
    284   prah = GNUNET_new (struct TALER_EXCHANGE_PostReservesAttestHandle);
    285   prah->ctx = ctx;
    286   prah->base_url = GNUNET_strdup (url);
    287   prah->keys = TALER_EXCHANGE_keys_incref (keys);
    288   GNUNET_CRYPTO_eddsa_key_get_public (&reserve_priv->eddsa_priv,
    289                                       &prah->reserve_pub.eddsa_pub);
    290   ts = GNUNET_TIME_timestamp_get ();
    291   TALER_wallet_reserve_attest_request_sign (ts,
    292                                             details,
    293                                             reserve_priv,
    294                                             &reserve_sig);
    295   prah->body = GNUNET_JSON_PACK (
    296     GNUNET_JSON_pack_data_auto ("reserve_sig",
    297                                 &reserve_sig),
    298     GNUNET_JSON_pack_timestamp ("request_timestamp",
    299                                 ts),
    300     GNUNET_JSON_pack_array_steal ("details",
    301                                   details));
    302   if (NULL == prah->body)
    303   {
    304     GNUNET_break (0);
    305     GNUNET_free (prah->base_url);
    306     TALER_EXCHANGE_keys_decref (prah->keys);
    307     GNUNET_free (prah);
    308     return NULL;
    309   }
    310   return prah;
    311 }
    312 
    313 
    314 enum TALER_ErrorCode
    315 TALER_EXCHANGE_post_reserves_attest_start (
    316   struct TALER_EXCHANGE_PostReservesAttestHandle *prah,
    317   TALER_EXCHANGE_PostReservesAttestCallback cb,
    318   TALER_EXCHANGE_POST_RESERVES_ATTEST_RESULT_CLOSURE *cb_cls)
    319 {
    320   CURL *eh;
    321   char arg_str[sizeof (struct TALER_ReservePublicKeyP) * 2 + 32];
    322 
    323   prah->cb = cb;
    324   prah->cb_cls = cb_cls;
    325   {
    326     char pub_str[sizeof (struct TALER_ReservePublicKeyP) * 2];
    327     char *end;
    328 
    329     end = GNUNET_STRINGS_data_to_string (
    330       &prah->reserve_pub,
    331       sizeof (prah->reserve_pub),
    332       pub_str,
    333       sizeof (pub_str));
    334     *end = '\0';
    335     GNUNET_snprintf (arg_str,
    336                      sizeof (arg_str),
    337                      "reserves-attest/%s",
    338                      pub_str);
    339   }
    340   prah->url = TALER_url_join (prah->base_url,
    341                               arg_str,
    342                               NULL);
    343   if (NULL == prah->url)
    344     return TALER_EC_GENERIC_CONFIGURATION_INVALID;
    345   eh = TALER_EXCHANGE_curl_easy_get_ (prah->url);
    346   if ( (NULL == eh) ||
    347        (GNUNET_OK !=
    348         TALER_curl_easy_post (&prah->post_ctx,
    349                               eh,
    350                               prah->body)) )
    351   {
    352     GNUNET_break (0);
    353     if (NULL != eh)
    354       curl_easy_cleanup (eh);
    355     GNUNET_free (prah->url);
    356     prah->url = NULL;
    357     return TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE;
    358   }
    359   prah->job = GNUNET_CURL_job_add2 (prah->ctx,
    360                                     eh,
    361                                     prah->post_ctx.headers,
    362                                     &handle_reserves_attest_finished,
    363                                     prah);
    364   if (NULL == prah->job)
    365   {
    366     TALER_curl_easy_post_finished (&prah->post_ctx);
    367     GNUNET_free (prah->url);
    368     prah->url = NULL;
    369     return TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE;
    370   }
    371   return TALER_EC_NONE;
    372 }
    373 
    374 
    375 void
    376 TALER_EXCHANGE_post_reserves_attest_cancel (
    377   struct TALER_EXCHANGE_PostReservesAttestHandle *prah)
    378 {
    379   if (NULL != prah->job)
    380   {
    381     GNUNET_CURL_job_cancel (prah->job);
    382     prah->job = NULL;
    383   }
    384   TALER_curl_easy_post_finished (&prah->post_ctx);
    385   json_decref (prah->body);
    386   GNUNET_free (prah->url);
    387   GNUNET_free (prah->base_url);
    388   TALER_EXCHANGE_keys_decref (prah->keys);
    389   GNUNET_free (prah);
    390 }
    391 
    392 
    393 /* end of exchange_api_post-reserves-attest-RESERVE_PUB.c */