exchange/src/lib/auditor_api_deposit_confirmation.c
2019-08-25 16:18:24 +02:00

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/*
This file is part of TALER
Copyright (C) 2014-2018 GNUnet e.V.
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 auditor-lib/auditor_api_deposit_confirmation.c
* @brief Implementation of the /deposit request of the auditor's HTTP API
* @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_auditor_service.h"
#include "auditor_api_handle.h"
#include "taler_signatures.h"
#include "auditor_api_curl_defaults.h"
/**
* @brief A DepositConfirmation Handle
*/
struct TALER_AUDITOR_DepositConfirmationHandle
{
/**
* The connection to auditor this request handle will use
*/
struct TALER_AUDITOR_Handle *auditor;
/**
* 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 TEAH_PostContext ctx;
/**
* Handle for the request.
*/
struct GNUNET_CURL_Job *job;
/**
* Function to call with the result.
*/
TALER_AUDITOR_DepositConfirmationResultCallback cb;
/**
* Closure for @a cb.
*/
void *cb_cls;
};
/**
* Function called when we're done processing the
* HTTP /deposit-confirmation request.
*
* @param cls the `struct TALER_AUDITOR_DepositConfirmationHandle`
* @param response_code HTTP response code, 0 on error
* @param djson parsed JSON result, NULL on error
*/
static void
handle_deposit_confirmation_finished (void *cls,
long response_code,
const void *djson)
{
const json_t *json = djson;
struct TALER_AUDITOR_DepositConfirmationHandle *dh = cls;
dh->job = NULL;
switch (response_code)
{
case 0:
break;
case MHD_HTTP_OK:
break;
case MHD_HTTP_BAD_REQUEST:
/* This should never happen, either us or the auditor is buggy
(or API version conflict); just pass JSON reply to the application */
break;
case MHD_HTTP_UNAUTHORIZED:
/* Nothing really to verify, auditor 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;
}
dh->cb (dh->cb_cls,
response_code,
TALER_JSON_get_error_code (json),
json);
TALER_AUDITOR_deposit_confirmation_cancel (dh);
}
/**
* Verify signature information about the deposit-confirmation.
*
* @param h_wire hash of merchant wire details
* @param h_contract_terms hash of the contact of the merchant with the customer (further details are never disclosed to the auditor)
* @param timestamp timestamp when the contract was finalized, must not be too far in the future
* @param refund_deadline date until which the merchant can issue a refund to the customer via the auditor (can be zero if refunds are not allowed); must not be after the @a wire_deadline
* @param amount_without_fee the amount confirmed to be wired by the exchange to the merchant
* @param coin_pub coins public key
* @param merchant_pub the public key of the merchant (used to identify the merchant for refund requests)
* @param exchange_sig the signature made with purpose #TALER_SIGNATURE_EXCHANGE_CONFIRM_DEPOSIT
* @param exchange_pub the public key of the exchange that matches @a exchange_sig
* @param master_pub master public key of the exchange
* @param ep_start when does @a exchange_pub validity start
* @param ep_expire when does @a exchange_pub usage end
* @param ep_end when does @a exchange_pub legal validity end
* @param master_sig master signature affirming validity of @a exchange_pub
* @return #GNUNET_OK if signatures are OK, #GNUNET_SYSERR if not
*/
static int
verify_signatures (const struct GNUNET_HashCode *h_wire,
const struct GNUNET_HashCode *h_contract_terms,
struct GNUNET_TIME_Absolute timestamp,
struct GNUNET_TIME_Absolute refund_deadline,
const struct TALER_Amount *amount_without_fee,
const struct TALER_CoinSpendPublicKeyP *coin_pub,
const struct TALER_MerchantPublicKeyP *merchant_pub,
const struct TALER_ExchangePublicKeyP *exchange_pub,
const struct TALER_ExchangeSignatureP *exchange_sig,
const struct TALER_MasterPublicKeyP *master_pub,
struct GNUNET_TIME_Absolute ep_start,
struct GNUNET_TIME_Absolute ep_expire,
struct GNUNET_TIME_Absolute ep_end,
const struct TALER_MasterSignatureP *master_sig)
{
struct TALER_DepositConfirmationPS dc;
struct TALER_ExchangeSigningKeyValidityPS sv;
dc.purpose.purpose = htonl (TALER_SIGNATURE_EXCHANGE_CONFIRM_DEPOSIT);
dc.purpose.size = htonl (sizeof (struct TALER_DepositConfirmationPS));
dc.h_contract_terms = *h_contract_terms;
dc.h_wire = *h_wire;
dc.timestamp = GNUNET_TIME_absolute_hton (timestamp);
dc.refund_deadline = GNUNET_TIME_absolute_hton (refund_deadline);
TALER_amount_hton (&dc.amount_without_fee,
amount_without_fee);
dc.coin_pub = *coin_pub;
dc.merchant = *merchant_pub;
if (GNUNET_OK !=
GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_EXCHANGE_CONFIRM_DEPOSIT,
&dc.purpose,
&exchange_sig->eddsa_signature,
&exchange_pub->eddsa_pub))
{
GNUNET_break_op (0);
TALER_LOG_WARNING ("Invalid signature on /deposit-confirmation request!\n");
{
TALER_LOG_DEBUG ("... amount_without_fee was %s\n",
TALER_amount2s (amount_without_fee));
}
return GNUNET_SYSERR;
}
sv.purpose.purpose = htonl (TALER_SIGNATURE_MASTER_SIGNING_KEY_VALIDITY);
sv.purpose.size = htonl (sizeof (struct TALER_ExchangeSigningKeyValidityPS));
sv.master_public_key = *master_pub;
sv.start = GNUNET_TIME_absolute_hton (ep_start);
sv.expire = GNUNET_TIME_absolute_hton (ep_expire);
sv.end = GNUNET_TIME_absolute_hton (ep_end);
sv.signkey_pub = *exchange_pub;
if (GNUNET_OK !=
GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_MASTER_SIGNING_KEY_VALIDITY,
&sv.purpose,
&master_sig->eddsa_signature,
&master_pub->eddsa_pub))
{
GNUNET_break (0);
TALER_LOG_WARNING ("Invalid signature on exchange signing key!\n");
return GNUNET_SYSERR;
}
if (0 == GNUNET_TIME_absolute_get_remaining (ep_end).rel_value_us)
{
GNUNET_break (0);
TALER_LOG_WARNING ("Exchange signing key is no longer valid!\n");
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Submit a deposit-confirmation permission to the auditor and get the
* auditor's response. Note that while we return the response
* verbatim to the caller for further processing, we do already verify
* that the response is well-formed. If the auditor's reply is not
* well-formed, we return an HTTP status code of zero to @a cb.
*
* We also verify that the @a exchange_sig is valid for this deposit-confirmation
* request, and that the @a master_sig is a valid signature for @a
* exchange_pub. Also, the @a auditor must be ready to operate (i.e. have
* finished processing the /version reply). If either check fails, we do
* NOT initiate the transaction with the auditor and instead return NULL.
*
* @param auditor the auditor handle; the auditor must be ready to operate
* @param h_wire hash of merchant wire details
* @param h_contract_terms hash of the contact of the merchant with the customer (further details are never disclosed to the auditor)
* @param timestamp timestamp when the contract was finalized, must not be too far in the future
* @param refund_deadline date until which the merchant can issue a refund to the customer via the auditor (can be zero if refunds are not allowed); must not be after the @a wire_deadline
* @param amount_without_fee the amount confirmed to be wired by the exchange to the merchant
* @param coin_pub coins public key
* @param merchant_pub the public key of the merchant (used to identify the merchant for refund requests)
* @param exchange_sig the signature made with purpose #TALER_SIGNATURE_EXCHANGE_CONFIRM_DEPOSIT
* @param exchange_pub the public key of the exchange that matches @a exchange_sig
* @param master_pub master public key of the exchange
* @param ep_start when does @a exchange_pub validity start
* @param ep_expire when does @a exchange_pub usage end
* @param ep_end when does @a exchange_pub legal validity end
* @param master_sig master signature affirming validity of @a exchange_pub
* @param cb the callback to call when a reply for this request is available
* @param cb_cls closure for the above callback
* @return a handle for this request; NULL if the inputs are invalid (i.e.
* signatures fail to verify). In this case, the callback is not called.
*/
struct TALER_AUDITOR_DepositConfirmationHandle *
TALER_AUDITOR_deposit_confirmation (struct TALER_AUDITOR_Handle *auditor,
const struct GNUNET_HashCode *h_wire,
const struct
GNUNET_HashCode *h_contract_terms,
struct GNUNET_TIME_Absolute timestamp,
struct GNUNET_TIME_Absolute refund_deadline,
const struct
TALER_Amount *amount_without_fee,
const struct
TALER_CoinSpendPublicKeyP *coin_pub,
const struct
TALER_MerchantPublicKeyP *merchant_pub,
const struct
TALER_ExchangePublicKeyP *exchange_pub,
const struct
TALER_ExchangeSignatureP *exchange_sig,
const struct
TALER_MasterPublicKeyP *master_pub,
struct GNUNET_TIME_Absolute ep_start,
struct GNUNET_TIME_Absolute ep_expire,
struct GNUNET_TIME_Absolute ep_end,
const struct
TALER_MasterSignatureP *master_sig,
TALER_AUDITOR_DepositConfirmationResultCallback
cb,
void *cb_cls)
{
struct TALER_AUDITOR_DepositConfirmationHandle *dh;
struct GNUNET_CURL_Context *ctx;
json_t *deposit_confirmation_obj;
CURL *eh;
(void) GNUNET_TIME_round_abs (&timestamp);
(void) GNUNET_TIME_round_abs (&refund_deadline);
(void) GNUNET_TIME_round_abs (&ep_start);
(void) GNUNET_TIME_round_abs (&ep_expire);
(void) GNUNET_TIME_round_abs (&ep_end);
GNUNET_assert (GNUNET_YES ==
MAH_handle_is_ready (auditor));
if (GNUNET_OK !=
verify_signatures (h_wire,
h_contract_terms,
timestamp,
refund_deadline,
amount_without_fee,
coin_pub,
merchant_pub,
exchange_pub,
exchange_sig,
master_pub,
ep_start,
ep_expire,
ep_end,
master_sig))
{
GNUNET_break_op (0);
return NULL;
}
deposit_confirmation_obj
= json_pack ("{s:o, s:o," /* H_wire, h_contract_terms */
" s:o, s:o," /* timestamp, refund_deadline */
" s:o, s:o," /* amount_without_fees, coin_pub */
" s:o, s:o," /* merchant_pub, exchange_sig */
" s:o, s:o," /* master_pub, ep_start */
" s:o, s:o," /* ep_expire, ep_end */
" s:o, s:o}", /* master_sig, exchange_pub */
"h_wire", GNUNET_JSON_from_data_auto (h_wire),
"h_contract_terms", GNUNET_JSON_from_data_auto (
h_contract_terms),
"timestamp", GNUNET_JSON_from_time_abs (timestamp),
"refund_deadline", GNUNET_JSON_from_time_abs (refund_deadline),
"amount_without_fee", TALER_JSON_from_amount (
amount_without_fee),
"coin_pub", GNUNET_JSON_from_data_auto (coin_pub),
"merchant_pub", GNUNET_JSON_from_data_auto (merchant_pub),
"exchange_sig", GNUNET_JSON_from_data_auto (exchange_sig),
"master_pub", GNUNET_JSON_from_data_auto (master_pub),
"ep_start", GNUNET_JSON_from_time_abs (ep_start),
"ep_expire", GNUNET_JSON_from_time_abs (ep_expire),
"ep_end", GNUNET_JSON_from_time_abs (ep_end),
"master_sig", GNUNET_JSON_from_data_auto (master_sig),
"exchange_pub", GNUNET_JSON_from_data_auto (exchange_pub));
if (NULL == deposit_confirmation_obj)
{
GNUNET_break (0);
return NULL;
}
dh = GNUNET_new (struct TALER_AUDITOR_DepositConfirmationHandle);
dh->auditor = auditor;
dh->cb = cb;
dh->cb_cls = cb_cls;
dh->url = MAH_path_to_url (auditor, "/deposit-confirmation");
eh = TAL_curl_easy_get (dh->url);
GNUNET_assert (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_CUSTOMREQUEST,
"PUT"));
if (GNUNET_OK !=
TALER_curl_easy_post (&dh->ctx,
eh,
deposit_confirmation_obj))
{
GNUNET_break (0);
curl_easy_cleanup (eh);
json_decref (deposit_confirmation_obj);
GNUNET_free (dh->url);
GNUNET_free (dh);
return NULL;
}
json_decref (deposit_confirmation_obj);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"URL for deposit-confirmation: `%s'\n",
dh->url);
ctx = MAH_handle_to_context (auditor);
dh->job = GNUNET_CURL_job_add2 (ctx,
eh,
dh->ctx.headers,
&handle_deposit_confirmation_finished,
dh);
return dh;
}
/**
* Cancel a deposit-confirmation permission request. This function cannot be used
* on a request handle if a response is already served for it.
*
* @param deposit-confirmation the deposit-confirmation permission request handle
*/
void
TALER_AUDITOR_deposit_confirmation_cancel (struct
TALER_AUDITOR_DepositConfirmationHandle
*deposit_confirmation)
{
if (NULL != deposit_confirmation->job)
{
GNUNET_CURL_job_cancel (deposit_confirmation->job);
deposit_confirmation->job = NULL;
}
GNUNET_free (deposit_confirmation->url);
TALER_curl_easy_post_finished (&deposit_confirmation->ctx);
GNUNET_free (deposit_confirmation);
}
/* end of auditor_api_deposit_confirmation.c */