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/*
This file is part of TALER
Copyright (C) 2014, 2015, 2016 GNUnet e.V. and INRIA
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, If not, see
<http://www.gnu.org/licenses/>
*/
/**
* @file lib/merchant_api_contract.c
* @brief Implementation of the /contract 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 <taler/taler_json_lib.h>
#include <taler/taler_signatures.h>
/**
* @brief A Contract Operation Handle
*/
struct TALER_MERCHANT_ContractOperation
{
/**
* The url for this request.
*/
char *url;
/**
* JSON encoding of the request to POST.
*/
char *json_enc;
/**
* Handle for the request.
*/
struct GNUNET_CURL_Job *job;
/**
* Function to call with the result.
*/
TALER_MERCHANT_ContractCallback 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 /contract request.
*
* @param cls the `struct TALER_MERCHANT_Pay`
* @param response_code HTTP response code, 0 on error
* @param json response body, NULL if not in JSON
*/
static void
handle_contract_finished (void *cls,
long response_code,
const json_t *json)
{
struct TALER_MERCHANT_ContractOperation *co = cls;
json_t *contract;
const struct TALER_MerchantSignatureP *sigp;
const struct GNUNET_HashCode *h_contractp;
struct TALER_MerchantSignatureP sig;
struct GNUNET_HashCode h_contract;
co->job = NULL;
contract = NULL;
sigp = NULL;
h_contractp = NULL;
switch (response_code)
{
case 0:
break;
case MHD_HTTP_OK:
{
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_json ("contract", &contract),
GNUNET_JSON_spec_fixed_auto ("merchant_sig", &sig),
GNUNET_JSON_spec_fixed_auto ("H_contract", &h_contract),
GNUNET_JSON_spec_end()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (json,
spec,
NULL, NULL))
{
GNUNET_break_op (0);
response_code = 0;
break;
}
h_contractp = &h_contract;
sigp = &sig;
}
break;
case MHD_HTTP_BAD_REQUEST:
/* This should never happen, either us or the merchant is buggy
(or API version conflict); just pass JSON reply to the application */
break;
case MHD_HTTP_FORBIDDEN:
break;
case MHD_HTTP_UNAUTHORIZED:
/* Nothing really to verify, merchant says one of the signatures is
invalid; as we checked them, this should never happen, we
should pass the JSON reply to the application */
break;
case MHD_HTTP_NOT_FOUND:
/* Nothing really to verify, this should never
happen, we should pass the JSON reply to the application */
break;
case MHD_HTTP_INTERNAL_SERVER_ERROR:
/* Server had an internal issue; we should retry, but this API
leaves this to the application */
break;
default:
/* unexpected response code */
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Unexpected response code %u\n",
(unsigned int) response_code);
GNUNET_break (0);
response_code = 0;
break;
}
co->cb (co->cb_cls,
response_code,
json,
contract,
sigp,
h_contractp);
if (NULL != contract)
json_decref (contract);
TALER_MERCHANT_contract_sign_cancel (co);
}
/**
* Request backend to sign a contract (and add fields like wire transfer
* details).
*
* @param ctx execution context
* @param backend_uri URI of the backend
* @param contract prototype of the contract
* @param contract_cb the callback to call when a reply for this request is available
* @param contract_cb_cls closure for @a contract_cb
* @return a handle for this request
*/
struct TALER_MERCHANT_ContractOperation *
TALER_MERCHANT_contract_sign (struct GNUNET_CURL_Context *ctx,
const char *backend_uri,
const json_t *contract,
TALER_MERCHANT_ContractCallback contract_cb,
void *contract_cb_cls)
{
struct TALER_MERCHANT_ContractOperation *co;
json_t *req;
CURL *eh;
co = GNUNET_new (struct TALER_MERCHANT_ContractOperation);
co->ctx = ctx;
co->cb = contract_cb;
co->cb_cls = contract_cb_cls;
co->url = GNUNET_strdup (backend_uri);
req = json_pack ("{s:O}",
"contract", (json_t *) contract);
eh = curl_easy_init ();
GNUNET_assert (NULL != (co->json_enc =
json_dumps (req,
JSON_COMPACT)));
json_decref (req);
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_URL,
co->url));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_POSTFIELDS,
co->json_enc));
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_POSTFIELDSIZE,
strlen (co->json_enc)));
co->job = GNUNET_CURL_job_add (ctx,
eh,
GNUNET_YES,
&handle_contract_finished,
co);
return co;
}
/**
* Cancel a /contract request. This function cannot be used
* on a request handle if a response is already served for it.
*
* @param co the contract operation request handle
*/
void
TALER_MERCHANT_contract_sign_cancel (struct TALER_MERCHANT_ContractOperation *co)
{
if (NULL != co->job)
{
GNUNET_CURL_job_cancel (co->job);
co->job = NULL;
}
GNUNET_free (co->url);
GNUNET_free (co->json_enc);
GNUNET_free (co);
}
/* end of merchant_api_contract.c */
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