exchange/src/lib/exchange_api_deposits_get.c
2020-03-17 17:47:53 +01:00

418 lines
13 KiB
C

/*
This file is part of TALER
Copyright (C) 2014-2020 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_deposits_get.c
* @brief Implementation of the /deposits/ GET 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_json_lib.h>
#include <gnunet/gnunet_curl_lib.h>
#include "taler_json_lib.h"
#include "taler_exchange_service.h"
#include "exchange_api_handle.h"
#include "taler_signatures.h"
#include "exchange_api_curl_defaults.h"
/**
* @brief A Deposit Wtid Handle
*/
struct TALER_EXCHANGE_DepositGetHandle
{
/**
* The connection to exchange this request handle will use
*/
struct TALER_EXCHANGE_Handle *exchange;
/**
* The url for this request.
*/
char *url;
/**
* Context for #TEH_curl_easy_post(). Keeps the data that must
* persist for Curl to make the upload.
*/
struct TALER_CURL_PostContext ctx;
/**
* Handle for the request.
*/
struct GNUNET_CURL_Job *job;
/**
* Function to call with the result.
*/
TALER_EXCHANGE_DepositGetCallback cb;
/**
* Closure for @a cb.
*/
void *cb_cls;
/**
* Information the exchange should sign in response.
* (with pre-filled fields from the request).
*/
struct TALER_ConfirmWirePS depconf;
};
/**
* Verify that the signature on the "200 OK" response
* from the exchange is valid.
*
* @param dwh deposit wtid handle
* @param json json reply with the signature
* @param[out] exchange_pub set to the exchange's public key
* @return #GNUNET_OK if the signature is valid, #GNUNET_SYSERR if not
*/
static int
verify_deposit_wtid_signature_ok (
const struct TALER_EXCHANGE_DepositGetHandle *dwh,
const json_t *json,
struct TALER_ExchangePublicKeyP *exchange_pub)
{
struct TALER_ExchangeSignatureP exchange_sig;
const struct TALER_EXCHANGE_Keys *key_state;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("exchange_sig", &exchange_sig),
GNUNET_JSON_spec_fixed_auto ("exchange_pub", exchange_pub),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (json,
spec,
NULL, NULL))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
key_state = TALER_EXCHANGE_get_keys (dwh->exchange);
if (GNUNET_OK !=
TALER_EXCHANGE_test_signing_key (key_state,
exchange_pub))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
if (GNUNET_OK !=
GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_EXCHANGE_CONFIRM_WIRE,
&dwh->depconf.purpose,
&exchange_sig.eddsa_signature,
&exchange_pub->eddsa_pub))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Function called when we're done processing the
* HTTP /track/transaction request.
*
* @param cls the `struct TALER_EXCHANGE_DepositGetHandle`
* @param response_code HTTP response code, 0 on error
* @param response parsed JSON result, NULL on error
*/
static void
handle_deposit_wtid_finished (void *cls,
long response_code,
const void *response)
{
struct TALER_EXCHANGE_DepositGetHandle *dwh = cls;
const struct TALER_WireTransferIdentifierRawP *wtid = NULL;
struct GNUNET_TIME_Absolute execution_time = GNUNET_TIME_UNIT_FOREVER_ABS;
const struct TALER_Amount *coin_contribution = NULL;
struct TALER_Amount coin_contribution_s;
struct TALER_ExchangePublicKeyP exchange_pub;
struct TALER_ExchangePublicKeyP *ep = NULL;
const json_t *j = response;
enum TALER_ErrorCode ec;
dwh->job = NULL;
switch (response_code)
{
case 0:
ec = TALER_EC_INVALID_RESPONSE;
break;
case MHD_HTTP_OK:
{
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("wtid", &dwh->depconf.wtid),
GNUNET_JSON_spec_absolute_time ("execution_time", &execution_time),
TALER_JSON_spec_amount ("coin_contribution", &coin_contribution_s),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (j,
spec,
NULL, NULL))
{
GNUNET_break_op (0);
response_code = 0;
ec = TALER_EC_DEPOSITS_INVALID_BODY_BY_EXCHANGE;
break;
}
wtid = &dwh->depconf.wtid;
dwh->depconf.execution_time = GNUNET_TIME_absolute_hton (execution_time);
TALER_amount_hton (&dwh->depconf.coin_contribution,
&coin_contribution_s);
coin_contribution = &coin_contribution_s;
if (GNUNET_OK !=
verify_deposit_wtid_signature_ok (dwh,
j,
&exchange_pub))
{
GNUNET_break_op (0);
response_code = 0;
ec = TALER_EC_DEPOSITS_INVALID_SIGNATURE_BY_EXCHANGE;
}
else
{
ep = &exchange_pub;
ec = TALER_EC_NONE;
}
}
break;
case MHD_HTTP_ACCEPTED:
{
/* Transaction known, but not executed yet */
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_absolute_time ("execution_time", &execution_time),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (j,
spec,
NULL, NULL))
{
GNUNET_break_op (0);
response_code = 0;
ec = TALER_EC_DEPOSITS_INVALID_BODY_BY_EXCHANGE;
break;
}
ec = TALER_EC_NONE;
}
break;
case MHD_HTTP_BAD_REQUEST:
ec = TALER_JSON_get_error_code (j);
/* This should never happen, either us or the exchange is buggy
(or API version conflict); just pass JSON reply to the application */
break;
case MHD_HTTP_FORBIDDEN:
ec = TALER_JSON_get_error_code (j);
/* 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 */
break;
case MHD_HTTP_NOT_FOUND:
ec = TALER_JSON_get_error_code (j);
/* Exchange does not know about transaction;
we should pass the reply to the application */
break;
case MHD_HTTP_INTERNAL_SERVER_ERROR:
ec = TALER_JSON_get_error_code (j);
/* 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);
ec = TALER_JSON_get_error_code (j);
response_code = 0;
break;
}
dwh->cb (dwh->cb_cls,
response_code,
ec,
ep,
j,
wtid,
execution_time,
coin_contribution);
TALER_EXCHANGE_deposits_get_cancel (dwh);
}
/**
* Obtain wire transfer details about an existing deposit operation.
*
* @param exchange the exchange to query
* @param merchant_priv the merchant's private key
* @param h_wire hash of merchant's wire transfer details
* @param h_contract_terms hash of the proposal data from the contract
* between merchant and customer
* @param coin_pub public key of the coin
* @param cb function to call with the result
* @param cb_cls closure for @a cb
* @return handle to abort request
*/
struct TALER_EXCHANGE_DepositGetHandle *
TALER_EXCHANGE_deposits_get (
struct TALER_EXCHANGE_Handle *exchange,
const struct TALER_MerchantPrivateKeyP *merchant_priv,
const struct GNUNET_HashCode *h_wire,
const struct GNUNET_HashCode *h_contract_terms,
const struct TALER_CoinSpendPublicKeyP *coin_pub,
TALER_EXCHANGE_DepositGetCallback cb,
void *cb_cls)
{
struct TALER_DepositTrackPS dtp;
struct TALER_MerchantSignatureP merchant_sig;
struct TALER_EXCHANGE_DepositGetHandle *dwh;
struct GNUNET_CURL_Context *ctx;
CURL *eh;
char arg_str[(sizeof (struct TALER_CoinSpendPublicKeyP)
+ sizeof (struct GNUNET_HashCode)
+ sizeof (struct TALER_MerchantPublicKeyP)
+ sizeof (struct GNUNET_HashCode)
+ sizeof (struct TALER_MerchantSignatureP)) * 2 + 48];
if (GNUNET_YES !=
TEAH_handle_is_ready (exchange))
{
GNUNET_break (0);
return NULL;
}
dtp.purpose.purpose = htonl (TALER_SIGNATURE_MERCHANT_TRACK_TRANSACTION);
dtp.purpose.size = htonl (sizeof (dtp));
dtp.h_contract_terms = *h_contract_terms;
dtp.h_wire = *h_wire;
GNUNET_CRYPTO_eddsa_key_get_public (&merchant_priv->eddsa_priv,
&dtp.merchant.eddsa_pub);
dtp.coin_pub = *coin_pub;
GNUNET_assert (GNUNET_OK ==
GNUNET_CRYPTO_eddsa_sign (&merchant_priv->eddsa_priv,
&dtp.purpose,
&merchant_sig.eddsa_sig));
{
char cpub_str[sizeof (struct TALER_CoinSpendPublicKeyP) * 2];
char mpub_str[sizeof (struct TALER_MerchantPublicKeyP) * 2];
char msig_str[sizeof (struct TALER_MerchantSignatureP) * 2];
char chash_str[sizeof (struct GNUNET_HashCode) * 2];
char whash_str[sizeof (struct GNUNET_HashCode) * 2];
char *end;
end = GNUNET_STRINGS_data_to_string (h_wire,
sizeof (struct
GNUNET_HashCode),
whash_str,
sizeof (whash_str));
*end = '\0';
end = GNUNET_STRINGS_data_to_string (&dtp.merchant,
sizeof (struct
TALER_MerchantPublicKeyP),
mpub_str,
sizeof (mpub_str));
*end = '\0';
end = GNUNET_STRINGS_data_to_string (h_contract_terms,
sizeof (struct
GNUNET_HashCode),
chash_str,
sizeof (chash_str));
*end = '\0';
end = GNUNET_STRINGS_data_to_string (coin_pub,
sizeof (struct
TALER_CoinSpendPublicKeyP),
cpub_str,
sizeof (cpub_str));
*end = '\0';
end = GNUNET_STRINGS_data_to_string (&merchant_sig,
sizeof (struct
TALER_MerchantSignatureP),
msig_str,
sizeof (msig_str));
*end = '\0';
GNUNET_snprintf (arg_str,
sizeof (arg_str),
"/deposits/%s/%s/%s/%s?merchant_sig=%s",
whash_str,
mpub_str,
chash_str,
cpub_str,
msig_str);
}
dwh = GNUNET_new (struct TALER_EXCHANGE_DepositGetHandle);
dwh->exchange = exchange;
dwh->cb = cb;
dwh->cb_cls = cb_cls;
dwh->url = TEAH_path_to_url (exchange,
arg_str);
dwh->depconf.purpose.size = htonl (sizeof (struct TALER_ConfirmWirePS));
dwh->depconf.purpose.purpose = htonl (TALER_SIGNATURE_EXCHANGE_CONFIRM_WIRE);
dwh->depconf.h_wire = *h_wire;
dwh->depconf.h_contract_terms = *h_contract_terms;
dwh->depconf.coin_pub = *coin_pub;
eh = TALER_EXCHANGE_curl_easy_get_ (dwh->url);
if (NULL == eh)
{
GNUNET_break (0);
GNUNET_free (dwh->url);
GNUNET_free (dwh);
return NULL;
}
ctx = TEAH_handle_to_context (exchange);
dwh->job = GNUNET_CURL_job_add (ctx,
eh,
GNUNET_NO,
&handle_deposit_wtid_finished,
dwh);
return dwh;
}
/**
* Cancel /deposits/$WTID request. This function cannot be used on a request
* handle if a response is already served for it.
*
* @param dwh the wire deposits request handle
*/
void
TALER_EXCHANGE_deposits_get_cancel (struct TALER_EXCHANGE_DepositGetHandle *dwh)
{
if (NULL != dwh->job)
{
GNUNET_CURL_job_cancel (dwh->job);
dwh->job = NULL;
}
GNUNET_free (dwh->url);
TALER_curl_easy_post_finished (&dwh->ctx);
GNUNET_free (dwh);
}
/* end of exchange_api_deposits_get.c */