exchange

exchange_api_post-reserves-RESERVE_PUB-open.c (15412B)

---

 /*
   This file is part of TALER
   Copyright (C) 2014-2026 Taler Systems SA
 
   TALER is free software; you can redistribute it and/or modify it under the
   terms of the GNU General Public License as published by the Free Software
   Foundation; either version 3, 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 General Public License for more details.
 
   You should have received a copy of the GNU General Public License along with
   TALER; see the file COPYING.  If not, see
   <http://www.gnu.org/licenses/>
 */
 /**
  * @file lib/exchange_api_post-reserves-RESERVE_PUB-open.c
  * @brief Implementation of the POST /reserves/$RESERVE_PUB/open requests
  * @author Christian Grothoff
  */
 #include <jansson.h>
 #include <microhttpd.h> /* just for HTTP open codes */
 #include <gnunet/gnunet_util_lib.h>
 #include <gnunet/gnunet_json_lib.h>
 #include <gnunet/gnunet_curl_lib.h>
 #include "taler/taler_json_lib.h"
 #include "exchange_api_common.h"
 #include "exchange_api_handle.h"
 #include "taler/taler_signatures.h"
 #include "exchange_api_curl_defaults.h"
 
 
 /**
  * Information we keep per coin to validate the reply.
  */
 struct CoinData
 {
   /**
    * Public key of the coin.
    */
   struct TALER_CoinSpendPublicKeyP coin_pub;
 
   /**
    * Signature by the coin.
    */
   struct TALER_CoinSpendSignatureP coin_sig;
 
   /**
    * The hash of the denomination's public key
    */
   struct TALER_DenominationHashP h_denom_pub;
 
   /**
    * How much did this coin contribute.
    */
   struct TALER_Amount contribution;
 };
 
 
 /**
  * @brief A POST /reserves/$RID/open Handle
  */
 struct TALER_EXCHANGE_PostReservesOpenHandle
 {
 
   /**
    * Reference to the execution context.
    */
   struct GNUNET_CURL_Context *ctx;
 
   /**
    * Base URL of the exchange.
    */
   char *base_url;
 
   /**
    * The url for this request, set during _start.
    */
   char *url;
 
   /**
    * Context for #TEH_curl_easy_post(). Keeps the data that must
    * persist for Curl to make the upload.
    */
   struct TALER_CURL_PostContext post_ctx;
 
   /**
    * Handle for the request.
    */
   struct GNUNET_CURL_Job *job;
 
   /**
    * Function to call with the result.
    */
   TALER_EXCHANGE_PostReservesOpenCallback cb;
 
   /**
    * Closure for @a cb.
    */
   TALER_EXCHANGE_POST_RESERVES_OPEN_RESULT_CLOSURE *cb_cls;
 
   /**
    * The keys of the exchange this request handle will use
    */
   struct TALER_EXCHANGE_Keys *keys;
 
   /**
    * Public key of the reserve we are querying.
    */
   struct TALER_ReservePublicKeyP reserve_pub;
 
   /**
    * Information we keep per coin to validate the reply.
    */
   struct CoinData *coins;
 
   /**
    * Length of the @e coins array.
    */
   unsigned int num_coins;
 
   /**
    * Pre-built JSON body for the request.
    */
   json_t *body;
 
 };
 
 
 /**
  * We received an #MHD_HTTP_OK open code. Handle the JSON
  * response.
  *
  * @param proh handle of the request
  * @param j JSON response
  * @return #GNUNET_OK on success
  */
 static enum GNUNET_GenericReturnValue
 handle_reserves_open_ok (struct TALER_EXCHANGE_PostReservesOpenHandle *proh,
                          const json_t *j)
 {
   struct TALER_EXCHANGE_PostReservesOpenResponse rs = {
     .hr.reply = j,
     .hr.http_status = MHD_HTTP_OK,
   };
   struct GNUNET_JSON_Specification spec[] = {
     TALER_JSON_spec_amount_any ("open_cost",
                                 &rs.details.ok.open_cost),
     GNUNET_JSON_spec_timestamp ("reserve_expiration",
                                 &rs.details.ok.expiration_time),
     GNUNET_JSON_spec_end ()
   };
 
   if (GNUNET_OK !=
       GNUNET_JSON_parse (j,
                          spec,
                          NULL,
                          NULL))
   {
     GNUNET_break_op (0);
     return GNUNET_SYSERR;
   }
   proh->cb (proh->cb_cls,
             &rs);
   proh->cb = NULL;
   GNUNET_JSON_parse_free (spec);
   return GNUNET_OK;
 }
 
 
 /**
  * We received an #MHD_HTTP_PAYMENT_REQUIRED open code. Handle the JSON
  * response.
  *
  * @param proh handle of the request
  * @param j JSON response
  * @return #GNUNET_OK on success
  */
 static enum GNUNET_GenericReturnValue
 handle_reserves_open_pr (struct TALER_EXCHANGE_PostReservesOpenHandle *proh,
                          const json_t *j)
 {
   struct TALER_EXCHANGE_PostReservesOpenResponse rs = {
     .hr.reply = j,
     .hr.http_status = MHD_HTTP_PAYMENT_REQUIRED,
   };
   struct GNUNET_JSON_Specification spec[] = {
     TALER_JSON_spec_amount_any ("open_cost",
                                 &rs.details.payment_required.open_cost),
     GNUNET_JSON_spec_timestamp ("reserve_expiration",
                                 &rs.details.payment_required.expiration_time),
     GNUNET_JSON_spec_end ()
   };
 
   if (GNUNET_OK !=
       GNUNET_JSON_parse (j,
                          spec,
                          NULL,
                          NULL))
   {
     GNUNET_break_op (0);
     return GNUNET_SYSERR;
   }
   proh->cb (proh->cb_cls,
             &rs);
   proh->cb = NULL;
   GNUNET_JSON_parse_free (spec);
   return GNUNET_OK;
 }
 
 
 /**
  * Function called when we're done processing the
  * HTTP /reserves/$RID/open request.
  *
  * @param cls the `struct TALER_EXCHANGE_PostReservesOpenHandle`
  * @param response_code HTTP response code, 0 on error
  * @param response parsed JSON result, NULL on error
  */
 static void
 handle_reserves_open_finished (void *cls,
                                long response_code,
                                const void *response)
 {
   struct TALER_EXCHANGE_PostReservesOpenHandle *proh = cls;
   const json_t *j = response;
   struct TALER_EXCHANGE_PostReservesOpenResponse rs = {
     .hr.reply = j,
     .hr.http_status = (unsigned int) response_code
   };
 
   proh->job = NULL;
   switch (response_code)
   {
   case 0:
     rs.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
     break;
   case MHD_HTTP_OK:
     if (GNUNET_OK !=
         handle_reserves_open_ok (proh,
                                  j))
     {
       GNUNET_break_op (0);
       rs.hr.http_status = 0;
       rs.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
     }
     break;
   case MHD_HTTP_BAD_REQUEST:
     /* This should never happen, either us or the exchange is buggy
        (or API version conflict); just pass JSON reply to the application */
     GNUNET_break (0);
     json_dumpf (j,
                 stderr,
                 JSON_INDENT (2));
     rs.hr.ec = TALER_JSON_get_error_code (j);
     rs.hr.hint = TALER_JSON_get_error_hint (j);
     break;
   case MHD_HTTP_PAYMENT_REQUIRED:
     if (GNUNET_OK !=
         handle_reserves_open_pr (proh,
                                  j))
     {
       GNUNET_break_op (0);
       rs.hr.http_status = 0;
       rs.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
     }
     break;
   case MHD_HTTP_FORBIDDEN:
     /* This should never happen, either us or the exchange is buggy
        (or API version conflict); just pass JSON reply to the application */
     GNUNET_break (0);
     rs.hr.ec = TALER_JSON_get_error_code (j);
     rs.hr.hint = TALER_JSON_get_error_hint (j);
     break;
   case MHD_HTTP_NOT_FOUND:
     /* Nothing really to verify, this should never
        happen, we should pass the JSON reply to the application */
     rs.hr.ec = TALER_JSON_get_error_code (j);
     rs.hr.hint = TALER_JSON_get_error_hint (j);
     break;
   case MHD_HTTP_CONFLICT:
     {
       const struct CoinData *cd = NULL;
       struct GNUNET_JSON_Specification spec[] = {
         GNUNET_JSON_spec_fixed_auto ("coin_pub",
                                      &rs.details.conflict.coin_pub),
         GNUNET_JSON_spec_end ()
       };
 
       if (GNUNET_OK !=
           GNUNET_JSON_parse (j,
                              spec,
                              NULL,
                              NULL))
       {
         GNUNET_break_op (0);
         rs.hr.http_status = 0;
         rs.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
         break;
       }
       for (unsigned int i = 0; i < proh->num_coins; i++)
       {
         const struct CoinData *cdi = &proh->coins[i];
 
         if (0 == GNUNET_memcmp (&rs.details.conflict.coin_pub,
                                 &cdi->coin_pub))
         {
           cd = cdi;
           break;
         }
       }
       if (NULL == cd)
       {
         GNUNET_break_op (0);
         rs.hr.http_status = 0;
         rs.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
         break;
       }
       rs.hr.ec = TALER_JSON_get_error_code (j);
       rs.hr.hint = TALER_JSON_get_error_hint (j);
       break;
     }
   case MHD_HTTP_INTERNAL_SERVER_ERROR:
     /* Server had an internal issue; we should retry, but this API
        leaves this to the application */
     rs.hr.ec = TALER_JSON_get_error_code (j);
     rs.hr.hint = TALER_JSON_get_error_hint (j);
     break;
   default:
     /* unexpected response code */
     GNUNET_break_op (0);
     rs.hr.ec = TALER_JSON_get_error_code (j);
     rs.hr.hint = TALER_JSON_get_error_hint (j);
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Unexpected response code %u/%d for reserves open\n",
                 (unsigned int) response_code,
                 (int) rs.hr.ec);
     break;
   }
   if (NULL != proh->cb)
   {
     proh->cb (proh->cb_cls,
               &rs);
     proh->cb = NULL;
   }
   TALER_EXCHANGE_post_reserves_open_cancel (proh);
 }
 
 
 struct TALER_EXCHANGE_PostReservesOpenHandle *
 TALER_EXCHANGE_post_reserves_open_create (
   struct GNUNET_CURL_Context *ctx,
   const char *url,
   struct TALER_EXCHANGE_Keys *keys,
   const struct TALER_ReservePrivateKeyP *reserve_priv,
   const struct TALER_Amount *reserve_contribution,
   unsigned int coin_payments_length,
   const struct TALER_EXCHANGE_PurseDeposit coin_payments[
     static coin_payments_length],
   struct GNUNET_TIME_Timestamp expiration_time,
   uint32_t min_purses)
 {
   struct TALER_EXCHANGE_PostReservesOpenHandle *proh;
   struct GNUNET_TIME_Timestamp ts;
   struct TALER_ReserveSignatureP reserve_sig;
   json_t *cpa;
 
   proh = GNUNET_new (struct TALER_EXCHANGE_PostReservesOpenHandle);
   proh->ctx = ctx;
   proh->base_url = GNUNET_strdup (url);
   proh->keys = TALER_EXCHANGE_keys_incref (keys);
   ts = GNUNET_TIME_timestamp_get ();
   GNUNET_CRYPTO_eddsa_key_get_public (&reserve_priv->eddsa_priv,
                                       &proh->reserve_pub.eddsa_pub);
   TALER_wallet_reserve_open_sign (reserve_contribution,
                                   ts,
                                   expiration_time,
                                   min_purses,
                                   reserve_priv,
                                   &reserve_sig);
   proh->coins = GNUNET_new_array (coin_payments_length,
                                   struct CoinData);
   proh->num_coins = coin_payments_length;
   cpa = json_array ();
   GNUNET_assert (NULL != cpa);
   for (unsigned int i = 0; i < coin_payments_length; i++)
   {
     const struct TALER_EXCHANGE_PurseDeposit *pd = &coin_payments[i];
     const struct TALER_AgeCommitmentProof *acp = pd->age_commitment_proof;
     struct TALER_AgeCommitmentHashP ahac;
     struct TALER_AgeCommitmentHashP *achp = NULL;
     struct CoinData *cd = &proh->coins[i];
     json_t *cp;
 
     cd->contribution = pd->amount;
     cd->h_denom_pub = pd->h_denom_pub;
     if (NULL != acp)
     {
       TALER_age_commitment_hash (&acp->commitment,
                                  &ahac);
       achp = &ahac;
     }
     TALER_wallet_reserve_open_deposit_sign (&pd->amount,
                                             &reserve_sig,
                                             &pd->coin_priv,
                                             &cd->coin_sig);
     GNUNET_CRYPTO_eddsa_key_get_public (&pd->coin_priv.eddsa_priv,
                                         &cd->coin_pub.eddsa_pub);
 
     cp = GNUNET_JSON_PACK (
       GNUNET_JSON_pack_allow_null (
         GNUNET_JSON_pack_data_auto ("h_age_commitment",
                                     achp)),
       TALER_JSON_pack_amount ("amount",
                               &pd->amount),
       GNUNET_JSON_pack_data_auto ("denom_pub_hash",
                                   &pd->h_denom_pub),
       TALER_JSON_pack_denom_sig ("ub_sig",
                                  &pd->denom_sig),
       GNUNET_JSON_pack_data_auto ("coin_pub",
                                   &cd->coin_pub),
       GNUNET_JSON_pack_data_auto ("coin_sig",
                                   &cd->coin_sig));
     GNUNET_assert (0 ==
                    json_array_append_new (cpa,
                                           cp));
   }
   proh->body = GNUNET_JSON_PACK (
     GNUNET_JSON_pack_timestamp ("request_timestamp",
                                 ts),
     GNUNET_JSON_pack_timestamp ("reserve_expiration",
                                 expiration_time),
     GNUNET_JSON_pack_array_steal ("payments",
                                   cpa),
     TALER_JSON_pack_amount ("reserve_payment",
                             reserve_contribution),
     GNUNET_JSON_pack_uint64 ("purse_limit",
                              min_purses),
     GNUNET_JSON_pack_data_auto ("reserve_sig",
                                 &reserve_sig));
   if (NULL == proh->body)
   {
     GNUNET_break (0);
     GNUNET_free (proh->coins);
     GNUNET_free (proh->base_url);
     TALER_EXCHANGE_keys_decref (proh->keys);
     GNUNET_free (proh);
     return NULL;
   }
   return proh;
 }
 
 
 enum TALER_ErrorCode
 TALER_EXCHANGE_post_reserves_open_start (
   struct TALER_EXCHANGE_PostReservesOpenHandle *proh,
   TALER_EXCHANGE_PostReservesOpenCallback cb,
   TALER_EXCHANGE_POST_RESERVES_OPEN_RESULT_CLOSURE *cb_cls)
 {
   CURL *eh;
   char arg_str[sizeof (struct TALER_ReservePublicKeyP) * 2 + 32];
 
   proh->cb = cb;
   proh->cb_cls = cb_cls;
   {
     char pub_str[sizeof (struct TALER_ReservePublicKeyP) * 2];
     char *end;
 
     end = GNUNET_STRINGS_data_to_string (
       &proh->reserve_pub,
       sizeof (proh->reserve_pub),
       pub_str,
       sizeof (pub_str));
     *end = '\0';
     GNUNET_snprintf (arg_str,
                      sizeof (arg_str),
                      "reserves/%s/open",
                      pub_str);
   }
   proh->url = TALER_url_join (proh->base_url,
                               arg_str,
                               NULL);
   if (NULL == proh->url)
     return TALER_EC_GENERIC_CONFIGURATION_INVALID;
   eh = TALER_EXCHANGE_curl_easy_get_ (proh->url);
   if ( (NULL == eh) ||
        (GNUNET_OK !=
         TALER_curl_easy_post (&proh->post_ctx,
                               eh,
                               proh->body)) )
   {
     GNUNET_break (0);
     if (NULL != eh)
       curl_easy_cleanup (eh);
     return TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE;
   }
   proh->job = GNUNET_CURL_job_add2 (proh->ctx,
                                     eh,
                                     proh->post_ctx.headers,
                                     &handle_reserves_open_finished,
                                     proh);
   if (NULL == proh->job)
     return TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE;
   return TALER_EC_NONE;
 }
 
 
 void
 TALER_EXCHANGE_post_reserves_open_cancel (
   struct TALER_EXCHANGE_PostReservesOpenHandle *proh)
 {
   if (NULL != proh->job)
   {
     GNUNET_CURL_job_cancel (proh->job);
     proh->job = NULL;
   }
   TALER_curl_easy_post_finished (&proh->post_ctx);
   json_decref (proh->body);
   GNUNET_free (proh->coins);
   GNUNET_free (proh->url);
   GNUNET_free (proh->base_url);
   TALER_EXCHANGE_keys_decref (proh->keys);
   GNUNET_free (proh);
 }
 
 
 /* end of exchange_api_post-reserves-RESERVE_PUB-open.c */