/*
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 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
*/
/**
* @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
#include
#include
#include
#include
#include "taler_json_lib.h"
#include "taler_mhd_lib.h"
#include "taler-exchange-httpd_deposit.h"
#include "taler-exchange-httpd_responses.h"
#include "taler-exchange-httpd_keystate.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_ExchangePublicKeyP pub;
struct TALER_ExchangeSignatureP sig;
struct TALER_DepositConfirmationPS dc = {
.purpose.purpose = htonl (TALER_SIGNATURE_EXCHANGE_CONFIRM_DEPOSIT),
.purpose.size = htonl (sizeof (dc)),
.h_contract_terms = *h_contract_terms,
.h_wire = *h_wire,
.timestamp = GNUNET_TIME_absolute_hton (timestamp),
.refund_deadline = GNUNET_TIME_absolute_hton (refund_deadline),
.coin_pub = *coin_pub,
.merchant = *merchant
};
TALER_amount_hton (&dc.amount_without_fee,
amount_without_fee);
if (GNUNET_OK !=
TEH_KS_sign (&dc.purpose,
&pub,
&sig))
{
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_EXCHANGE_BAD_CONFIGURATION,
"no keys");
}
return TALER_MHD_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_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 = TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_DEPOSIT_HISTORY_DB_ERROR,
"Could not check for existing identical deposit");
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; skip RECOUP as revoked
denominations are not eligible for deposit, and if we are the old coin
pub of a revoked coin (aka a zombie), then ONLY refresh is allowed. */
{
struct TALER_EXCHANGEDB_TransactionList *tl;
qs = TEH_plugin->get_coin_transactions (TEH_plugin->cls,
session,
&deposit->coin.coin_pub,
GNUNET_NO,
&tl);
if (0 > qs)
{
if (GNUNET_DB_STATUS_HARD_ERROR == qs)
*mhd_ret = TALER_MHD_reply_with_error (
connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_DEPOSIT_HISTORY_DB_ERROR,
"could not fetch coin transaction history");
return qs;
}
if (GNUNET_OK !=
TALER_EXCHANGEDB_calculate_transaction_list_totals (tl,
&spent, /* starting offset */
&spent /* result */))
{
TEH_plugin->free_coin_transaction_list (TEH_plugin->cls,
tl);
*mhd_ret = TALER_MHD_reply_with_error (
connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_DEPOSIT_HISTORY_DB_ERROR,
"could not calculate historic coin amount total");
return GNUNET_DB_STATUS_HARD_ERROR;
}
/* Check that cost of all transactions (including the current one) is
smaller (or equal) 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,
&deposit->coin.
coin_pub,
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 = TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_DEPOSIT_STORE_DB_ERROR,
"Could not persist /deposit data");
}
return qs;
}
/**
* 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 (after all, this is basically about
which year the deposit counts for in terms of tax purposes) */
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 "/coins/$COIN_PUB/deposit" request. Parses the JSON, and, if
* successful, passes the JSON data to #deposit_transaction() 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 connection the MHD connection to handle
* @param coin_pub public key of the coin
* @param root uploaded JSON data
* @return MHD result code
*/
int
TEH_handler_deposit (struct MHD_Connection *connection,
const struct TALER_CoinSpendPublicKeyP *coin_pub,
const json_t *root)
{
json_t *wire;
struct DepositContext dc;
struct TALER_EXCHANGEDB_Deposit deposit;
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 ("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 ()
};
memset (&deposit,
0,
sizeof (deposit));
deposit.coin.coin_pub = *coin_pub;
{
int res;
res = TALER_MHD_parse_json_data (connection,
root,
spec);
if (GNUNET_SYSERR == res)
{
GNUNET_break (0);
return MHD_NO; /* hard failure */
}
if (GNUNET_NO == res)
{
GNUNET_break_op (0);
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 TALER_MHD_reply_with_error (connection,
MHD_HTTP_BAD_REQUEST,
TALER_EC_DEPOSIT_REFUND_DEADLINE_AFTER_WIRE_DEADLINE,
"refund_deadline");
}
if (GNUNET_OK !=
check_timestamp_current (deposit.timestamp))
{
GNUNET_break_op (0);
GNUNET_JSON_parse_free (spec);
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_BAD_REQUEST,
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 TALER_MHD_reply_with_error (connection,
MHD_HTTP_BAD_REQUEST,
TALER_EC_DEPOSIT_INVALID_WIRE_FORMAT_JSON,
"wire");
}
if (0 != GNUNET_memcmp (&deposit.h_wire,
&my_h_wire))
{
/* Client hashed wire details differently than we did, reject */
GNUNET_JSON_parse_free (spec);
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_BAD_REQUEST,
TALER_EC_DEPOSIT_INVALID_WIRE_FORMAT_CONTRACT_HASH_CONFLICT,
"h_wire");
}
/* check denomination exists and is valid */
{
struct TEH_KS_StateHandle *key_state;
struct TALER_EXCHANGEDB_DenominationKey *dki;
enum TALER_ErrorCode ec;
unsigned int hc;
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 TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
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,
&ec,
&hc);
if (NULL == dki)
{
TALER_LOG_WARNING ("Unknown denomination key in /deposit request\n");
TEH_KS_release (key_state);
GNUNET_JSON_parse_free (spec);
return TALER_MHD_reply_with_error (connection,
hc,
ec,
"Could not find denomination key used in deposit");
}
TALER_amount_ntoh (&deposit.deposit_fee,
&dki->issue.properties.fee_deposit);
if (GNUNET_YES !=
TALER_amount_cmp_currency (&deposit.amount_with_fee,
&deposit.deposit_fee) )
{
GNUNET_break_op (0);
TEH_KS_release (key_state);
GNUNET_JSON_parse_free (spec);
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_BAD_REQUEST,
TALER_EC_DEPOSIT_CURRENCY_MISSMATCH,
"contribution");
}
/* 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 TALER_MHD_reply_with_error (connection,
MHD_HTTP_UNAUTHORIZED,
TALER_EC_DEPOSIT_DENOMINATION_SIGNATURE_INVALID,
"ub_sig");
}
TALER_amount_ntoh (&deposit.deposit_fee,
&dki->issue.properties.fee_deposit);
TALER_amount_ntoh (&dc.value,
&dki->issue.properties.value);
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 TALER_MHD_reply_with_error (connection,
MHD_HTTP_BAD_REQUEST,
TALER_EC_DEPOSIT_NEGATIVE_VALUE_AFTER_FEE,
"deposited amount smaller than depositing fee");
}
/* make sure coin is 'known' in database */
{
int mhd_ret;
struct TEH_DB_KnowCoinContext kcc = {
.coin = &deposit.coin,
.connection = connection
};
if (GNUNET_OK !=
TEH_DB_run_transaction (connection,
"know coin for deposit",
&mhd_ret,
&TEH_DB_know_coin_transaction,
&kcc))
{
GNUNET_JSON_parse_free (spec);
return mhd_ret;
}
}
/* check deposit signature */
{
struct TALER_DepositRequestPS dr = {
.purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_DEPOSIT),
.purpose.size = htonl (sizeof (dr)),
.h_contract_terms = deposit.h_contract_terms,
.h_wire = deposit.h_wire,
.timestamp = GNUNET_TIME_absolute_hton (deposit.timestamp),
.refund_deadline = GNUNET_TIME_absolute_hton (deposit.refund_deadline),
.merchant = deposit.merchant_pub,
.coin_pub = deposit.coin.coin_pub
};
TALER_amount_hton (&dr.amount_with_fee,
&deposit.amount_with_fee);
TALER_amount_hton (&dr.deposit_fee,
&deposit.deposit_fee);
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");
GNUNET_JSON_parse_free (spec);
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_UNAUTHORIZED,
TALER_EC_DEPOSIT_COIN_SIGNATURE_INVALID,
"coin_sig");
}
}
/* execute transaction */
dc.deposit = &deposit;
{
int mhd_ret;
if (GNUNET_OK !=
TEH_DB_run_transaction (connection,
"execute deposit",
&mhd_ret,
&deposit_transaction,
&dc))
{
GNUNET_JSON_parse_free (spec);
return mhd_ret;
}
}
/* generate regular response */
{
struct TALER_Amount amount_without_fee;
int res;
GNUNET_assert (GNUNET_SYSERR !=
TALER_amount_subtract (&amount_without_fee,
&deposit.amount_with_fee,
&deposit.deposit_fee));
res = 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);
GNUNET_JSON_parse_free (spec);
return res;
}
}
/* end of taler-exchange-httpd_deposit.c */