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exchange/src/exchange/taler-exchange-httpd_deposit.c

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/*
This file is part of TALER
Copyright (C) 2014-2017 Inria and GNUnet e.V.
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU Affero 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 Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with
TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file taler-exchange-httpd_deposit.c
* @brief Handle /deposit requests; parses the POST and JSON and
* verifies the coin signature before handing things off
* to the database.
* @author Florian Dold
* @author Benedikt Mueller
* @author Christian Grothoff
*/
#include "platform.h"
#include <gnunet/gnunet_util_lib.h>
#include <gnunet/gnunet_json_lib.h>
#include <jansson.h>
#include <microhttpd.h>
#include <pthread.h>
#include "taler_json_lib.h"
#include "taler-exchange-httpd_parsing.h"
#include "taler-exchange-httpd_deposit.h"
#include "taler-exchange-httpd_responses.h"
#include "taler-exchange-httpd_keystate.h"
#include "taler-exchange-httpd_validation.h"
/**
* Send confirmation of deposit success to client. This function
* will create a signed message affirming the given information
* and return it to the client. By this, the exchange affirms that
* the coin had sufficient (residual) value for the specified
* transaction and that it will execute the requested deposit
* operation with the given wiring details.
*
* @param connection connection to the client
* @param coin_pub public key of the coin
* @param h_wire hash of wire details
* @param h_contract_terms hash of contract details
* @param timestamp client's timestamp
* @param refund_deadline until when this deposit be refunded
* @param merchant merchant public key
* @param amount_without_fee fraction of coin value to deposit, without the fee
* @return MHD result code
*/
static int
reply_deposit_success (struct MHD_Connection *connection,
const struct TALER_CoinSpendPublicKeyP *coin_pub,
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_MerchantPublicKeyP *merchant,
const struct TALER_Amount *amount_without_fee)
{
struct TALER_DepositConfirmationPS dc;
struct TALER_ExchangePublicKeyP pub;
struct TALER_ExchangeSignatureP sig;
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;
if (GNUNET_OK !=
TEH_KS_sign (&dc.purpose,
&pub,
&sig))
{
return TEH_RESPONSE_reply_internal_error (connection,
TALER_EC_EXCHANGE_BAD_CONFIGURATION,
"no keys");
}
return TEH_RESPONSE_reply_json_pack (connection,
MHD_HTTP_OK,
"{s:s, s:o, s:o}",
"status", "DEPOSIT_OK",
"sig", GNUNET_JSON_from_data_auto (&sig),
"pub", GNUNET_JSON_from_data_auto (&pub));
}
/**
* Closure for #deposit_transaction.
*/
struct DepositContext
{
/**
* Information about the deposit request.
*/
const struct TALER_EXCHANGEDB_Deposit *deposit;
/**
* Value of the coin.
*/
struct TALER_Amount value;
};
/**
* Execute database transaction for /deposit. Runs the transaction
* logic; IF it returns a non-error code, the transaction logic MUST
* NOT queue a MHD response. IF it returns an hard error, the
* transaction logic MUST queue a MHD response and set @a mhd_ret. IF
* it returns the soft error code, the function MAY be called again to
* retry and MUST not queue a MHD response.
*
* @param cls a `struct DepositContext`
* @param connection MHD request context
* @param session database session and transaction to use
* @param[out] mhd_ret set to MHD status on error
* @return transaction status
*/
static enum GNUNET_DB_QueryStatus
deposit_transaction (void *cls,
struct MHD_Connection *connection,
struct TALER_EXCHANGEDB_Session *session,
int *mhd_ret)
{
struct DepositContext *dc = cls;
const struct TALER_EXCHANGEDB_Deposit *deposit = dc->deposit;
struct TALER_EXCHANGEDB_TransactionList *tl;
struct TALER_Amount spent;
enum GNUNET_DB_QueryStatus qs;
qs = TEH_plugin->have_deposit (TEH_plugin->cls,
session,
deposit,
GNUNET_YES /* check refund deadline */);
if (qs < 0)
{
if (GNUNET_DB_STATUS_HARD_ERROR == qs)
{
*mhd_ret = TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_DEPOSIT_HISTORY_DB_ERROR);
return GNUNET_DB_STATUS_HARD_ERROR;
}
return qs;
}
if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT == qs)
{
struct TALER_Amount amount_without_fee;
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"/deposit replay, accepting again!\n");
GNUNET_assert (GNUNET_OK ==
TALER_amount_subtract (&amount_without_fee,
&deposit->amount_with_fee,
&deposit->deposit_fee));
*mhd_ret = reply_deposit_success (connection,
&deposit->coin.coin_pub,
&deposit->h_wire,
&deposit->h_contract_terms,
deposit->timestamp,
deposit->refund_deadline,
&deposit->merchant_pub,
&amount_without_fee);
/* Treat as 'hard' DB error as we want to rollback and
never try again. */
return GNUNET_DB_STATUS_HARD_ERROR;
}
/* Start with fee for THIS transaction */
spent = deposit->amount_with_fee;
/* add cost of all previous transactions */
qs = TEH_plugin->get_coin_transactions (TEH_plugin->cls,
session,
&deposit->coin.coin_pub,
GNUNET_NO,
&tl);
if (0 > qs)
return qs;
if (GNUNET_OK !=
TEH_DB_calculate_transaction_list_totals (tl,
&spent,
&spent))
{
TEH_plugin->free_coin_transaction_list (TEH_plugin->cls,
tl);
*mhd_ret = TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_DEPOSIT_HISTORY_DB_ERROR);
return GNUNET_DB_STATUS_HARD_ERROR;
}
/* Check that cost of all transactions is smaller than
the value of the coin. */
if (0 < TALER_amount_cmp (&spent,
&dc->value))
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Deposited coin has insufficient funds left!\n");
*mhd_ret = TEH_RESPONSE_reply_coin_insufficient_funds (connection,
TALER_EC_DEPOSIT_INSUFFICIENT_FUNDS,
tl);
TEH_plugin->free_coin_transaction_list (TEH_plugin->cls,
tl);
return GNUNET_DB_STATUS_HARD_ERROR;
}
TEH_plugin->free_coin_transaction_list (TEH_plugin->cls,
tl);
qs = TEH_plugin->insert_deposit (TEH_plugin->cls,
session,
deposit);
if (GNUNET_DB_STATUS_HARD_ERROR == qs)
{
TALER_LOG_WARNING ("Failed to store /deposit information in database\n");
*mhd_ret = TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_DEPOSIT_STORE_DB_ERROR);
}
return qs;
}
/**
* We have parsed the JSON information about the deposit, do some
* basic sanity checks (especially that the signature on the coin is
* valid, and that this type of coin exists) and then execute the
* deposit.
*
* @param connection the MHD connection to handle
* @param deposit information about the deposit
* @return MHD result code
*/
static int
verify_and_execute_deposit (struct MHD_Connection *connection,
const struct TALER_EXCHANGEDB_Deposit *deposit)
{
struct TALER_DepositRequestPS dr;
int mhd_ret;
struct TALER_Amount amount_without_fee;
struct DepositContext dc;
struct TEH_KS_StateHandle *mks;
const struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dki;
/* check signature */
dr.purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_DEPOSIT);
dr.purpose.size = htonl (sizeof (struct TALER_DepositRequestPS));
dr.h_contract_terms = deposit->h_contract_terms;
dr.h_wire = deposit->h_wire;
dr.timestamp = GNUNET_TIME_absolute_hton (deposit->timestamp);
dr.refund_deadline = GNUNET_TIME_absolute_hton (deposit->refund_deadline);
TALER_amount_hton (&dr.amount_with_fee,
&deposit->amount_with_fee);
TALER_amount_hton (&dr.deposit_fee,
&deposit->deposit_fee);
dr.merchant = deposit->merchant_pub;
dr.coin_pub = deposit->coin.coin_pub;
if (GNUNET_OK !=
GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_WALLET_COIN_DEPOSIT,
&dr.purpose,
&deposit->csig.eddsa_signature,
&deposit->coin.coin_pub.eddsa_pub))
{
TALER_LOG_WARNING ("Invalid signature on /deposit request\n");
return TEH_RESPONSE_reply_signature_invalid (connection,
TALER_EC_DEPOSIT_COIN_SIGNATURE_INVALID,
"coin_sig");
}
/* check denomination */
mks = TEH_KS_acquire (GNUNET_TIME_absolute_get ());
if (NULL == mks)
{
TALER_LOG_ERROR ("Lacking keys to operate\n");
return TEH_RESPONSE_reply_internal_error (connection,
TALER_EC_EXCHANGE_BAD_CONFIGURATION,
"no keys");
}
dki = TEH_KS_denomination_key_lookup_by_hash (mks,
&deposit->coin.denom_pub_hash,
TEH_KS_DKU_DEPOSIT);
if (NULL == dki)
{
TEH_KS_release (mks);
return TEH_RESPONSE_reply_internal_db_error (connection,
TALER_EC_DEPOSIT_DB_DENOMINATION_KEY_UNKNOWN);
}
TALER_amount_ntoh (&dc.value,
&dki->issue.properties.value);
TEH_KS_release (mks);
/* execute transaction */
dc.deposit = deposit;
if (GNUNET_OK !=
TEH_DB_run_transaction (connection,
"execute deposit",
&mhd_ret,
&deposit_transaction,
&dc))
return mhd_ret;
/* generate regular response */
GNUNET_assert (GNUNET_SYSERR !=
TALER_amount_subtract (&amount_without_fee,
&deposit->amount_with_fee,
&deposit->deposit_fee));
return reply_deposit_success (connection,
&deposit->coin.coin_pub,
&deposit->h_wire,
&deposit->h_contract_terms,
deposit->timestamp,
deposit->refund_deadline,
&deposit->merchant_pub,
&amount_without_fee);
}
/**
* Check that @a ts is reasonably close to our own RTC.
*
* @param ts timestamp to check
* @return #GNUNET_OK if @a ts is reasonable
*/
static int
check_timestamp_current (struct GNUNET_TIME_Absolute ts)
{
struct GNUNET_TIME_Relative r;
struct GNUNET_TIME_Relative tolerance;
/* Let's be VERY generous */
tolerance = GNUNET_TIME_UNIT_MONTHS;
r = GNUNET_TIME_absolute_get_duration (ts);
if (r.rel_value_us > tolerance.rel_value_us)
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Deposit timestamp too old: %llu vs %llu > %llu\n",
(unsigned long long) ts.abs_value_us,
(unsigned long long) GNUNET_TIME_absolute_get().abs_value_us,
(unsigned long long) tolerance.rel_value_us);
return GNUNET_SYSERR;
}
r = GNUNET_TIME_absolute_get_remaining (ts);
if (r.rel_value_us > tolerance.rel_value_us)
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Deposit timestamp too new: %llu vs %llu < - %llu\n",
(unsigned long long) ts.abs_value_us,
(unsigned long long) GNUNET_TIME_absolute_get().abs_value_us,
(unsigned long long) tolerance.rel_value_us);
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Handle a "/deposit" request. Parses the JSON, and, if successful,
* passes the JSON data to #verify_and_execute_deposit() to further
* check the details of the operation specified. If everything checks
* out, this will ultimately lead to the "/deposit" being executed, or
* rejected.
*
* @param rh context of the handler
* @param connection the MHD connection to handle
* @param[in,out] connection_cls the connection's closure (can be updated)
* @param upload_data upload data
* @param[in,out] upload_data_size number of bytes (left) in @a upload_data
* @return MHD result code
*/
int
TEH_DEPOSIT_handler_deposit (struct TEH_RequestHandler *rh,
struct MHD_Connection *connection,
void **connection_cls,
const char *upload_data,
size_t *upload_data_size)
{
json_t *json;
int res;
json_t *wire;
char *emsg;
enum TALER_ErrorCode ec;
struct TALER_EXCHANGEDB_Deposit deposit;
struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dki;
struct TEH_KS_StateHandle *key_state;
struct GNUNET_HashCode my_h_wire;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_json ("wire", &wire),
TALER_JSON_spec_amount ("contribution", &deposit.amount_with_fee),
GNUNET_JSON_spec_fixed_auto ("denom_pub_hash", &deposit.coin.denom_pub_hash),
TALER_JSON_spec_denomination_signature ("ub_sig", &deposit.coin.denom_sig),
GNUNET_JSON_spec_fixed_auto ("coin_pub", &deposit.coin.coin_pub),
GNUNET_JSON_spec_fixed_auto ("merchant_pub", &deposit.merchant_pub),
GNUNET_JSON_spec_fixed_auto ("h_contract_terms", &deposit.h_contract_terms),
GNUNET_JSON_spec_fixed_auto ("H_wire", &deposit.h_wire),
GNUNET_JSON_spec_fixed_auto ("coin_sig", &deposit.csig),
GNUNET_JSON_spec_absolute_time ("timestamp", &deposit.timestamp),
GNUNET_JSON_spec_absolute_time ("refund_deadline", &deposit.refund_deadline),
GNUNET_JSON_spec_absolute_time ("wire_transfer_deadline", &deposit.wire_deadline),
GNUNET_JSON_spec_end ()
};
res = TEH_PARSE_post_json (connection,
connection_cls,
upload_data,
upload_data_size,
&json);
if (GNUNET_SYSERR == res)
return MHD_NO;
if ( (GNUNET_NO == res) ||
(NULL == json) )
return MHD_YES;
memset (&deposit,
0,
sizeof (deposit));
res = TEH_PARSE_json_data (connection,
json,
spec);
json_decref (json);
if (GNUNET_SYSERR == res)
return MHD_NO; /* hard failure */
if (GNUNET_NO == res)
return MHD_YES; /* failure */
deposit.receiver_wire_account = wire;
if (deposit.refund_deadline.abs_value_us > deposit.wire_deadline.abs_value_us)
{
GNUNET_break_op (0);
GNUNET_JSON_parse_free (spec);
return TEH_RESPONSE_reply_arg_invalid (connection,
TALER_EC_DEPOSIT_REFUND_DEADLINE_AFTER_WIRE_DEADLINE,
"refund_deadline");
}
if (TALER_EC_NONE !=
(ec = TEH_json_validate_wireformat (wire,
&emsg)))
{
GNUNET_JSON_parse_free (spec);
res = TEH_RESPONSE_reply_external_error (connection,
ec,
emsg);
GNUNET_free (emsg);
return res;
}
if (GNUNET_OK !=
check_timestamp_current (deposit.timestamp))
{
GNUNET_break_op (0);
GNUNET_JSON_parse_free (spec);
return TEH_RESPONSE_reply_arg_invalid (connection,
TALER_EC_DEPOSIT_INVALID_TIMESTAMP,
"timestamp");
}
if (GNUNET_OK !=
TALER_JSON_merchant_wire_signature_hash (wire,
&my_h_wire))
{
TALER_LOG_WARNING ("Failed to parse JSON wire format specification for /deposit request\n");
GNUNET_JSON_parse_free (spec);
return TEH_RESPONSE_reply_arg_invalid (connection,
TALER_EC_DEPOSIT_INVALID_WIRE_FORMAT_JSON,
"wire");
}
if (0 != GNUNET_memcmp (&deposit.h_wire,
&my_h_wire))
{
/* Client hashed contract differently than we did, reject */
GNUNET_JSON_parse_free (spec);
return TEH_RESPONSE_reply_arg_invalid (connection,
TALER_EC_DEPOSIT_INVALID_WIRE_FORMAT_CONTRACT_HASH_CONFLICT,
"H_wire");
}
/* check denomination exists and is valid */
key_state = TEH_KS_acquire (GNUNET_TIME_absolute_get ());
if (NULL == key_state)
{
TALER_LOG_ERROR ("Lacking keys to operate\n");
GNUNET_JSON_parse_free (spec);
return TEH_RESPONSE_reply_internal_error (connection,
TALER_EC_EXCHANGE_BAD_CONFIGURATION,
"no keys");
}
dki = TEH_KS_denomination_key_lookup_by_hash (key_state,
&deposit.coin.denom_pub_hash,
TEH_KS_DKU_DEPOSIT);
if (NULL == dki)
{
/* FIXME: #3887: if DK was revoked, we might want to give a 403 and not a 404! */
TEH_KS_release (key_state);
TALER_LOG_WARNING ("Unknown denomination key in /deposit request\n");
GNUNET_JSON_parse_free (spec);
return TEH_RESPONSE_reply_arg_unknown (connection,
TALER_EC_DEPOSIT_DENOMINATION_KEY_UNKNOWN,
"denom_pub");
}
TALER_amount_ntoh (&deposit.deposit_fee,
&dki->issue.properties.fee_deposit);
/* check coin signature */
if (GNUNET_YES !=
TALER_test_coin_valid (&deposit.coin,
&dki->denom_pub))
{
TALER_LOG_WARNING ("Invalid coin passed for /deposit\n");
TEH_KS_release (key_state);
GNUNET_JSON_parse_free (spec);
return TEH_RESPONSE_reply_signature_invalid (connection,
TALER_EC_DEPOSIT_DENOMINATION_SIGNATURE_INVALID,
"ub_sig");
}
TALER_amount_ntoh (&deposit.deposit_fee,
&dki->issue.properties.fee_deposit);
TEH_KS_release (key_state);
if (0 < TALER_amount_cmp (&deposit.deposit_fee,
&deposit.amount_with_fee))
{
GNUNET_break_op (0);
GNUNET_JSON_parse_free (spec);
return TEH_RESPONSE_reply_external_error (connection,
TALER_EC_DEPOSIT_NEGATIVE_VALUE_AFTER_FEE,
"deposited amount smaller than depositing fee");
}
/* make sure coin is 'known' in database */
{
struct TEH_DB_KnowCoinContext kcc;
int mhd_ret;
kcc.coin = &deposit.coin;
kcc.connection = connection;
if (GNUNET_OK !=
TEH_DB_run_transaction (connection,
"know coin for deposit",
&mhd_ret,
&TEH_DB_know_coin_transaction,
&kcc))
return mhd_ret;
}
res = verify_and_execute_deposit (connection,
&deposit);
GNUNET_JSON_parse_free (spec);
return res;
}
/* end of taler-exchange-httpd_deposit.c */
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