merchant

merchant_api_get_config.c (9781B)

---

 /*
   This file is part of TALER
   Copyright (C) 2014-2025 Taler Systems SA
 
   TALER is free software; you can redistribute it and/or modify it under the
   terms of the GNU Lesser General Public License as published by the Free Software
   Foundation; either version 2.1, or (at your option) any later version.
 
   TALER is distributed in the hope that it will be useful, but WITHOUT ANY
   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
   A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
 
   You should have received a copy of the GNU Lesser General Public License along with
   TALER; see the file COPYING.LGPL.  If not, see
   <http://www.gnu.org/licenses/>
 */
 /**
  * @file merchant_api_get_config.c
  * @brief Implementation of the /config request of the merchant's HTTP API
  * @author Christian Grothoff
  */
 #include "platform.h"
 #include <curl/curl.h>
 #include <jansson.h>
 #include <microhttpd.h> /* just for HTTP status codes */
 #include <gnunet/gnunet_util_lib.h>
 #include <gnunet/gnunet_curl_lib.h>
 #include "taler_merchant_service.h"
 #include "merchant_api_curl_defaults.h"
 #include <taler/taler_json_lib.h>
 #include <taler/taler_signatures.h>
 
 /**
  * Which version of the Taler protocol is implemented
  * by this library?  Used to determine compatibility.
  */
 #define MERCHANT_PROTOCOL_CURRENT 24
 
 /**
  * How many configs are we backwards-compatible with?
  */
 #define MERCHANT_PROTOCOL_AGE 0
 
 /**
  * How many exchanges do we allow at most per merchant?
  */
 #define MAX_EXCHANGES 1024
 
 /**
  * How many currency specs do we allow at most per merchant?
  */
 #define MAX_CURRENCIES 1024
 
 /**
  * @brief A handle for /config operations
  */
 struct TALER_MERCHANT_ConfigGetHandle
 {
   /**
    * The url for this request.
    */
   char *url;
 
   /**
    * Handle for the request.
    */
   struct GNUNET_CURL_Job *job;
 
   /**
    * Function to call with the result.
    */
   TALER_MERCHANT_ConfigCallback cb;
 
   /**
    * Closure for @a cb.
    */
   void *cb_cls;
 
   /**
    * Reference to the execution context.
    */
   struct GNUNET_CURL_Context *ctx;
 
 };
 
 
 /**
  * Function called when we're done processing the
  * HTTP /config request.
  *
  * @param cls the `struct TALER_MERCHANT_ConfigGetHandle`
  * @param response_code HTTP response code, 0 on error
  * @param response response body, NULL if not in JSON
  */
 static void
 handle_config_finished (void *cls,
                         long response_code,
                         const void *response)
 {
   struct TALER_MERCHANT_ConfigGetHandle *vgh = cls;
   const json_t *json = response;
   struct TALER_MERCHANT_ConfigResponse cr = {
     .hr.http_status = (unsigned int) response_code,
     .hr.reply = json
   };
 
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Got /config response with status code %u\n",
               (unsigned int) response_code);
 
   vgh->job = NULL;
   switch (response_code)
   {
   case MHD_HTTP_OK:
     {
       const json_t *jcs;
       const json_t *exchanges = NULL;
       struct TALER_MERCHANT_ExchangeConfigInfo *eci = NULL;
       unsigned int num_eci = 0;
       unsigned int nspec;
       struct TALER_JSON_ProtocolVersion pv;
       struct GNUNET_JSON_Specification spec[] = {
         GNUNET_JSON_spec_object_const ("currencies",
                                        &jcs),
         GNUNET_JSON_spec_array_const ("exchanges",
                                       &exchanges),
         GNUNET_JSON_spec_string ("currency",
                                  &cr.details.ok.ci.currency),
         TALER_JSON_spec_version ("version",
                                  &pv),
         GNUNET_JSON_spec_string ("version",
                                  &cr.details.ok.ci.version),
         GNUNET_JSON_spec_end ()
       };
 
       cr.details.ok.compat = TALER_MERCHANT_VC_PROTOCOL_ERROR;
       if (GNUNET_OK !=
           GNUNET_JSON_parse (json,
                              spec,
                              NULL, NULL))
       {
         GNUNET_break_op (0);
         cr.hr.http_status = 0;
         cr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
         break;
       }
       cr.details.ok.compat = TALER_MERCHANT_VC_MATCH;
       if (MERCHANT_PROTOCOL_CURRENT < pv.current)
       {
         cr.details.ok.compat |= TALER_MERCHANT_VC_NEWER;
         if (MERCHANT_PROTOCOL_CURRENT < pv.current - pv.age)
           cr.details.ok.compat |= TALER_MERCHANT_VC_INCOMPATIBLE;
       }
       if (MERCHANT_PROTOCOL_CURRENT > pv.current)
       {
         cr.details.ok.compat |= TALER_MERCHANT_VC_OLDER;
         if (MERCHANT_PROTOCOL_CURRENT - MERCHANT_PROTOCOL_AGE > pv.current)
           cr.details.ok.compat |= TALER_MERCHANT_VC_INCOMPATIBLE;
       }
 
       nspec = (unsigned int) json_object_size (jcs);
       if ( (nspec > MAX_CURRENCIES) ||
            (json_object_size (jcs) != (size_t) nspec) )
       {
         GNUNET_break_op (0);
         cr.hr.http_status = 0;
         cr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
         break;
       }
       if (NULL != exchanges)
       {
         num_eci = (unsigned int) json_object_size (exchanges);
         if ( (num_eci > MAX_EXCHANGES) ||
              (json_object_size (exchanges) != (size_t) num_eci) )
         {
           GNUNET_break_op (0);
           cr.hr.http_status = 0;
           cr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
           break;
         }
         eci = GNUNET_new_array (num_eci,
                                 struct TALER_MERCHANT_ExchangeConfigInfo);
         for (unsigned int i = 0; i<num_eci; i++)
         {
           struct TALER_MERCHANT_ExchangeConfigInfo *ei = &eci[i];
           const json_t *ej = json_array_get (exchanges,
                                              i);
           struct GNUNET_JSON_Specification ispec[] = {
             GNUNET_JSON_spec_string ("currency",
                                      &ei->currency),
             GNUNET_JSON_spec_string ("base_url",
                                      &ei->base_url),
             GNUNET_JSON_spec_fixed_auto ("master_pub",
                                          &ei->master_pub),
             GNUNET_JSON_spec_end ()
           };
 
           if (GNUNET_OK !=
               GNUNET_JSON_parse (ej,
                                  ispec,
                                  NULL, NULL))
           {
             GNUNET_break_op (0);
             cr.hr.http_status = 0;
             cr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
             GNUNET_free (eci);
             break;
           }
         }
       }
       {
         struct TALER_CurrencySpecification *cspecs;
         unsigned int off = 0;
         json_t *obj;
         const char *curr;
 
         cspecs = GNUNET_new_array (nspec,
                                    struct TALER_CurrencySpecification);
         cr.details.ok.num_cspecs = nspec;
         cr.details.ok.cspecs = cspecs;
         cr.details.ok.num_exchanges = (unsigned int) num_eci;
         cr.details.ok.exchanges = eci;
         json_object_foreach ((json_t *) jcs, curr, obj)
         {
           struct TALER_CurrencySpecification *cs = &cspecs[off++];
           struct GNUNET_JSON_Specification cspec[] = {
             TALER_JSON_spec_currency_specification (curr,
                                                     curr,
                                                     cs),
             GNUNET_JSON_spec_end ()
           };
 
           if (GNUNET_OK !=
               GNUNET_JSON_parse (jcs,
                                  cspec,
                                  NULL, NULL))
           {
             GNUNET_break_op (0);
             cr.hr.http_status = 0;
             cr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
             GNUNET_free (eci);
             TALER_CONFIG_free_currencies (off - 1,
                                           cspecs);
             break;
           }
         }
         vgh->cb (vgh->cb_cls,
                  &cr);
         GNUNET_free (eci);
         TALER_CONFIG_free_currencies (nspec,
                                       cspecs);
       }
       TALER_MERCHANT_config_get_cancel (vgh);
       return;
     }
   default:
     /* unexpected response code */
     cr.hr.ec = TALER_JSON_get_error_code (json);
     cr.hr.hint = TALER_JSON_get_error_hint (json);
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Unexpected response code %u/%d\n",
                 (unsigned int) response_code,
                 (int) cr.hr.ec);
     break;
   }
   vgh->cb (vgh->cb_cls,
            &cr);
   TALER_MERCHANT_config_get_cancel (vgh);
 }
 
 
 struct TALER_MERCHANT_ConfigGetHandle *
 TALER_MERCHANT_config_get (struct GNUNET_CURL_Context *ctx,
                            const char *backend_url,
                            TALER_MERCHANT_ConfigCallback config_cb,
                            void *config_cb_cls)
 {
   struct TALER_MERCHANT_ConfigGetHandle *vgh;
   CURL *eh;
 
   vgh = GNUNET_new (struct TALER_MERCHANT_ConfigGetHandle);
   vgh->ctx = ctx;
   vgh->cb = config_cb;
   vgh->cb_cls = config_cb_cls;
   vgh->url = TALER_url_join (backend_url,
                              "config",
                              NULL);
   if (NULL == vgh->url)
   {
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Could not construct request URL.\n");
     GNUNET_free (vgh);
     return NULL;
   }
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Requesting URL '%s'\n",
               vgh->url);
   eh = TALER_MERCHANT_curl_easy_get_ (vgh->url);
   vgh->job = GNUNET_CURL_job_add (ctx,
                                   eh,
                                   &handle_config_finished,
                                   vgh);
   return vgh;
 }
 
 
 void
 TALER_MERCHANT_config_get_cancel (struct TALER_MERCHANT_ConfigGetHandle *vgh)
 {
   if (NULL != vgh->job)
   {
     GNUNET_CURL_job_cancel (vgh->job);
     vgh->job = NULL;
   }
   GNUNET_free (vgh->url);
   GNUNET_free (vgh);
 }
 
 
 /* end of merchant_api_config_get.c */