/*
This file is part of TALER
Copyright (C) 2014-2021 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_transfers_get.c
* @brief Implementation of the GET /transfers/ request
* @author Christian Grothoff
*/
#include "platform.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_exchange_service.h"
#include "taler_json_lib.h"
#include "exchange_api_handle.h"
#include "taler_signatures.h"
#include "exchange_api_curl_defaults.h"
/**
* @brief A /transfers/ GET Handle
*/
struct TALER_EXCHANGE_TransfersGetHandle
{
/**
* The connection to exchange this request handle will use
*/
struct TALER_EXCHANGE_Handle *exchange;
/**
* The url for this request.
*/
char *url;
/**
* Handle for the request.
*/
struct GNUNET_CURL_Job *job;
/**
* Function to call with the result.
*/
TALER_EXCHANGE_TransfersGetCallback cb;
/**
* Closure for @a cb.
*/
void *cb_cls;
};
/**
* We got a #MHD_HTTP_OK response for the /transfers/ request.
* Check that the response is well-formed and if it is, call the
* callback. If not, return an error code.
*
* This code is very similar to
* merchant_api_track_transfer.c::check_transfers_get_response_ok.
* Any changes should likely be reflected there as well.
*
* @param wdh handle to the operation
* @param json response we got
* @return #GNUNET_OK if we are done and all is well,
* #GNUNET_SYSERR if the response was bogus
*/
static enum GNUNET_GenericReturnValue
check_transfers_get_response_ok (
struct TALER_EXCHANGE_TransfersGetHandle *wdh,
const json_t *json)
{
json_t *details_j;
struct TALER_Amount total_expected;
struct TALER_MerchantPublicKeyP merchant_pub;
struct TALER_EXCHANGE_TransfersGetResponse tgr = {
.hr.reply = json,
.hr.http_status = MHD_HTTP_OK
};
struct TALER_EXCHANGE_TransferData *td
= &tgr.details.ok.td;
struct GNUNET_JSON_Specification spec[] = {
TALER_JSON_spec_amount_any ("total",
&td->total_amount),
TALER_JSON_spec_amount_any ("wire_fee",
&td->wire_fee),
GNUNET_JSON_spec_fixed_auto ("merchant_pub",
&merchant_pub),
GNUNET_JSON_spec_fixed_auto ("h_payto",
&td->h_payto),
GNUNET_JSON_spec_timestamp ("execution_time",
&td->execution_time),
GNUNET_JSON_spec_json ("deposits",
&details_j),
GNUNET_JSON_spec_fixed_auto ("exchange_sig",
&td->exchange_sig),
GNUNET_JSON_spec_fixed_auto ("exchange_pub",
&td->exchange_pub),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (json,
spec,
NULL, NULL))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
if (GNUNET_OK !=
TALER_amount_set_zero (td->total_amount.currency,
&total_expected))
{
GNUNET_break_op (0);
GNUNET_JSON_parse_free (spec);
return GNUNET_SYSERR;
}
if (GNUNET_OK !=
TALER_EXCHANGE_test_signing_key (
TALER_EXCHANGE_get_keys (wdh->exchange),
&td->exchange_pub))
{
GNUNET_break_op (0);
GNUNET_JSON_parse_free (spec);
return GNUNET_SYSERR;
}
td->details_length = json_array_size (details_j);
{
struct GNUNET_HashContext *hash_context;
struct TALER_TrackTransferDetails *details;
details = GNUNET_new_array (td->details_length,
struct TALER_TrackTransferDetails);
td->details = details;
hash_context = GNUNET_CRYPTO_hash_context_start ();
for (unsigned int i = 0; i<td->details_length; i++)
{
struct TALER_TrackTransferDetails *detail = &details[i];
struct json_t *detail_j = json_array_get (details_j, i);
struct GNUNET_JSON_Specification spec_detail[] = {
GNUNET_JSON_spec_fixed_auto ("h_contract_terms",
&detail->h_contract_terms),
GNUNET_JSON_spec_fixed_auto ("coin_pub", &detail->coin_pub),
TALER_JSON_spec_amount_any ("deposit_value", &detail->coin_value),
TALER_JSON_spec_amount_any ("deposit_fee", &detail->coin_fee),
GNUNET_JSON_spec_end ()
};
if ( (GNUNET_OK !=
GNUNET_JSON_parse (detail_j,
spec_detail,
NULL, NULL)) ||
(GNUNET_OK !=
TALER_amount_cmp_currency (&total_expected,
&detail->coin_value)) ||
(GNUNET_OK !=
TALER_amount_cmp_currency (&total_expected,
&detail->coin_fee)) ||
(0 >
TALER_amount_add (&total_expected,
&total_expected,
&detail->coin_value)) ||
(0 >
TALER_amount_subtract (&total_expected,
&total_expected,
&detail->coin_fee)) )
{
GNUNET_break_op (0);
GNUNET_CRYPTO_hash_context_abort (hash_context);
GNUNET_JSON_parse_free (spec);
GNUNET_free (details);
return GNUNET_SYSERR;
}
/* build up big hash for signature checking later */
TALER_exchange_online_wire_deposit_append (
hash_context,
&detail->h_contract_terms,
td->execution_time,
&detail->coin_pub,
&detail->coin_value,
&detail->coin_fee);
}
/* Check signature */
{
struct GNUNET_HashCode h_details;
GNUNET_CRYPTO_hash_context_finish (hash_context,
&h_details);
if (GNUNET_OK !=
TALER_exchange_online_wire_deposit_verify (
&td->total_amount,
&td->wire_fee,
&merchant_pub,
&td->h_payto,
&h_details,
&td->exchange_pub,
&td->exchange_sig))
{
GNUNET_break_op (0);
GNUNET_JSON_parse_free (spec);
GNUNET_free (details);
return GNUNET_SYSERR;
}
}
if (0 >
TALER_amount_subtract (&total_expected,
&total_expected,
&td->wire_fee))
{
GNUNET_break_op (0);
GNUNET_JSON_parse_free (spec);
GNUNET_free (details);
return GNUNET_SYSERR;
}
if (0 !=
TALER_amount_cmp (&total_expected,
&td->total_amount))
{
GNUNET_break_op (0);
GNUNET_JSON_parse_free (spec);
GNUNET_free (details);
return GNUNET_SYSERR;
}
wdh->cb (wdh->cb_cls,
&tgr);
GNUNET_free (details);
}
GNUNET_JSON_parse_free (spec);
TALER_EXCHANGE_transfers_get_cancel (wdh);
return GNUNET_OK;
}
/**
* Function called when we're done processing the
* HTTP /transfers/ request.
*
* @param cls the `struct TALER_EXCHANGE_TransfersGetHandle`
* @param response_code HTTP response code, 0 on error
* @param response parsed JSON result, NULL on error
*/
static void
handle_transfers_get_finished (void *cls,
long response_code,
const void *response)
{
struct TALER_EXCHANGE_TransfersGetHandle *wdh = cls;
const json_t *j = response;
struct TALER_EXCHANGE_TransfersGetResponse tgr = {
.hr.reply = j,
.hr.http_status = (unsigned int) response_code
};
wdh->job = NULL;
switch (response_code)
{
case 0:
tgr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
break;
case MHD_HTTP_OK:
if (GNUNET_OK ==
check_transfers_get_response_ok (wdh,
j))
return;
GNUNET_break_op (0);
tgr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
tgr.hr.http_status = 0;
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 */
tgr.hr.ec = TALER_JSON_get_error_code (j);
tgr.hr.hint = TALER_JSON_get_error_hint (j);
break;
case MHD_HTTP_FORBIDDEN:
/* Nothing really to verify, exchange says one of the signatures is
invalid; as we checked them, this should never happen, we
should pass the JSON reply to the application */
tgr.hr.ec = TALER_JSON_get_error_code (j);
tgr.hr.hint = TALER_JSON_get_error_hint (j);
break;
case MHD_HTTP_NOT_FOUND:
/* Exchange does not know about transaction;
we should pass the reply to the application */
tgr.hr.ec = TALER_JSON_get_error_code (j);
tgr.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 */
tgr.hr.ec = TALER_JSON_get_error_code (j);
tgr.hr.hint = TALER_JSON_get_error_hint (j);
break;
default:
/* unexpected response code */
GNUNET_break_op (0);
tgr.hr.ec = TALER_JSON_get_error_code (j);
tgr.hr.hint = TALER_JSON_get_error_hint (j);
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Unexpected response code %u/%d for transfers get\n",
(unsigned int) response_code,
(int) tgr.hr.ec);
break;
}
wdh->cb (wdh->cb_cls,
&tgr);
TALER_EXCHANGE_transfers_get_cancel (wdh);
}
struct TALER_EXCHANGE_TransfersGetHandle *
TALER_EXCHANGE_transfers_get (
struct TALER_EXCHANGE_Handle *exchange,
const struct TALER_WireTransferIdentifierRawP *wtid,
TALER_EXCHANGE_TransfersGetCallback cb,
void *cb_cls)
{
struct TALER_EXCHANGE_TransfersGetHandle *wdh;
struct GNUNET_CURL_Context *ctx;
CURL *eh;
char arg_str[sizeof (struct TALER_WireTransferIdentifierRawP) * 2 + 32];
if (GNUNET_YES !=
TEAH_handle_is_ready (exchange))
{
GNUNET_break (0);
return NULL;
}
wdh = GNUNET_new (struct TALER_EXCHANGE_TransfersGetHandle);
wdh->exchange = exchange;
wdh->cb = cb;
wdh->cb_cls = cb_cls;
{
char wtid_str[sizeof (struct TALER_WireTransferIdentifierRawP) * 2];
char *end;
end = GNUNET_STRINGS_data_to_string (wtid,
sizeof (struct
TALER_WireTransferIdentifierRawP),
wtid_str,
sizeof (wtid_str));
*end = '\0';
GNUNET_snprintf (arg_str,
sizeof (arg_str),
"/transfers/%s",
wtid_str);
}
wdh->url = TEAH_path_to_url (wdh->exchange,
arg_str);
if (NULL == wdh->url)
{
GNUNET_free (wdh);
return NULL;
}
eh = TALER_EXCHANGE_curl_easy_get_ (wdh->url);
if (NULL == eh)
{
GNUNET_break (0);
GNUNET_free (wdh->url);
GNUNET_free (wdh);
return NULL;
}
ctx = TEAH_handle_to_context (exchange);
wdh->job = GNUNET_CURL_job_add_with_ct_json (ctx,
eh,
&handle_transfers_get_finished,
wdh);
return wdh;
}
/**
* Cancel wire deposits request. This function cannot be used on a request
* handle if a response is already served for it.
*
* @param wdh the wire deposits request handle
*/
void
TALER_EXCHANGE_transfers_get_cancel (
struct TALER_EXCHANGE_TransfersGetHandle *wdh)
{
if (NULL != wdh->job)
{
GNUNET_CURL_job_cancel (wdh->job);
wdh->job = NULL;
}
GNUNET_free (wdh->url);
GNUNET_free (wdh);
}
/* end of exchange_api_transfers_get.c */