/*
This file is part of TALER
Copyright (C) 2014-2022 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_batch-withdraw.c
* @brief Handle /reserves/$RESERVE_PUB/batch-withdraw requests
* @author Florian Dold
* @author Benedikt Mueller
* @author Christian Grothoff
*/
#include "platform.h"
#include
#include
#include "taler_json_lib.h"
#include "taler_mhd_lib.h"
#include "taler-exchange-httpd_batch-withdraw.h"
#include "taler-exchange-httpd_responses.h"
#include "taler-exchange-httpd_keys.h"
/**
* Information per planchet in the batch.
*/
struct PlanchetContext
{
/**
* Hash of the (blinded) message to be signed by the Exchange.
*/
struct TALER_BlindedCoinHashP h_coin_envelope;
/**
* Value of the coin being exchanged (matching the denomination key)
* plus the transaction fee. We include this in what is being
* signed so that we can verify a reserve's remaining total balance
* without needing to access the respective denomination key
* information each time.
*/
struct TALER_Amount amount_with_fee;
/**
* Blinded planchet.
*/
struct TALER_BlindedPlanchet blinded_planchet;
/**
* Set to the resulting signed coin data to be returned to the client.
*/
struct TALER_EXCHANGEDB_CollectableBlindcoin collectable;
};
/**
* Context for #batch_withdraw_transaction.
*/
struct BatchWithdrawContext
{
/**
* Public key of the reserv.
*/
const struct TALER_ReservePublicKeyP *reserve_pub;
/**
* KYC status of the reserve used for the operation.
*/
struct TALER_EXCHANGEDB_KycStatus kyc;
/**
* Array of @e planchets_length planchets we are processing.
*/
struct PlanchetContext *planchets;
/**
* Total amount from all coins with fees.
*/
struct TALER_Amount batch_total;
/**
* Length of the @e planchets array.
*/
unsigned int planchets_length;
};
/**
* Function implementing withdraw transaction. 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.
*
* Note that "wc->collectable.sig" is set before entering this function as we
* signed before entering the transaction.
*
* @param cls a `struct BatchWithdrawContext *`
* @param connection MHD request which triggered the transaction
* @param[out] mhd_ret set to MHD response status for @a connection,
* if transaction failed (!)
* @return transaction status
*/
static enum GNUNET_DB_QueryStatus
batch_withdraw_transaction (void *cls,
struct MHD_Connection *connection,
MHD_RESULT *mhd_ret)
{
struct BatchWithdrawContext *wc = cls;
struct GNUNET_TIME_Timestamp now;
uint64_t ruuid;
enum GNUNET_DB_QueryStatus qs;
bool balance_ok = false;
bool found = false;
now = GNUNET_TIME_timestamp_get ();
qs = TEH_plugin->do_batch_withdraw (TEH_plugin->cls,
now,
wc->reserve_pub,
&wc->batch_total,
&found,
&balance_ok,
&wc->kyc,
&ruuid);
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_GENERIC_DB_FETCH_FAILED,
"update_reserve_batch_withdraw");
return qs;
}
if (! found)
{
*mhd_ret = TALER_MHD_reply_with_error (connection,
MHD_HTTP_NOT_FOUND,
TALER_EC_EXCHANGE_GENERIC_RESERVE_UNKNOWN,
NULL);
return GNUNET_DB_STATUS_HARD_ERROR;
}
if (! balance_ok)
{
TEH_plugin->rollback (TEH_plugin->cls);
*mhd_ret = TEH_RESPONSE_reply_reserve_insufficient_balance (
connection,
&wc->batch_total,
wc->reserve_pub);
return GNUNET_DB_STATUS_HARD_ERROR;
}
if ( (TEH_KYC_NONE != TEH_kyc_config.mode) &&
(! wc->kyc.ok) &&
(TALER_EXCHANGEDB_KYC_W2W == wc->kyc.type) )
{
/* Wallet-to-wallet payments _always_ require KYC */
*mhd_ret = TALER_MHD_REPLY_JSON_PACK (
connection,
MHD_HTTP_UNAVAILABLE_FOR_LEGAL_REASONS,
GNUNET_JSON_pack_uint64 ("payment_target_uuid",
wc->kyc.payment_target_uuid));
return GNUNET_DB_STATUS_HARD_ERROR;
}
if ( (TEH_KYC_NONE != TEH_kyc_config.mode) &&
(! wc->kyc.ok) &&
(TALER_EXCHANGEDB_KYC_WITHDRAW == wc->kyc.type) &&
(! GNUNET_TIME_relative_is_zero (TEH_kyc_config.withdraw_period)) )
{
/* Withdraws require KYC if above threshold */
enum GNUNET_DB_QueryStatus qs2;
bool below_limit;
qs2 = TEH_plugin->do_withdraw_limit_check (
TEH_plugin->cls,
ruuid,
GNUNET_TIME_absolute_subtract (now.abs_time,
TEH_kyc_config.withdraw_period),
&TEH_kyc_config.withdraw_limit,
&below_limit);
if (0 > qs2)
{
GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs2);
if (GNUNET_DB_STATUS_HARD_ERROR == qs2)
*mhd_ret = TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_GENERIC_DB_FETCH_FAILED,
"do_withdraw_limit_check");
return qs2;
}
if (! below_limit)
{
*mhd_ret = TALER_MHD_REPLY_JSON_PACK (
connection,
MHD_HTTP_UNAVAILABLE_FOR_LEGAL_REASONS,
GNUNET_JSON_pack_uint64 ("payment_target_uuid",
wc->kyc.payment_target_uuid));
return GNUNET_DB_STATUS_HARD_ERROR;
}
}
/* Add information about each planchet in the batch */
for (unsigned int i = 0; iplanchets_length; i++)
{
struct PlanchetContext *pc = &wc->planchets[i];
const struct TALER_BlindedPlanchet *bp = &pc->blinded_planchet;
const struct TALER_CsNonce *nonce;
bool denom_unknown = true;
bool conflict = true;
bool nonce_reuse = true;
nonce = (TALER_DENOMINATION_CS == bp->cipher)
? &bp->details.cs_blinded_planchet.nonce
: NULL;
qs = TEH_plugin->do_batch_withdraw_insert (TEH_plugin->cls,
nonce,
&pc->collectable,
now,
ruuid,
&denom_unknown,
&conflict,
&nonce_reuse);
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_GENERIC_DB_FETCH_FAILED,
"do_withdraw");
return qs;
}
if (denom_unknown)
{
GNUNET_break (0);
*mhd_ret = TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_GENERIC_DB_INVARIANT_FAILURE,
NULL);
return GNUNET_DB_STATUS_HARD_ERROR;
}
if ( (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs) ||
(conflict) )
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Idempotent coin in batch, not allowed. Aborting.\n");
*mhd_ret = TALER_MHD_reply_with_error (connection,
MHD_HTTP_CONFLICT,
TALER_EC_EXCHANGE_WITHDRAW_BATCH_IDEMPOTENT_PLANCHET,
NULL);
return GNUNET_DB_STATUS_HARD_ERROR;
}
if (nonce_reuse)
{
GNUNET_break_op (0);
*mhd_ret = TALER_MHD_reply_with_error (connection,
MHD_HTTP_BAD_REQUEST,
TALER_EC_EXCHANGE_WITHDRAW_NONCE_REUSE,
NULL);
return GNUNET_DB_STATUS_HARD_ERROR;
}
}
TEH_METRICS_num_success[TEH_MT_SUCCESS_BATCH_WITHDRAW]++;
return GNUNET_DB_STATUS_SUCCESS_ONE_RESULT;
}
/**
* Generates our final (successful) response.
*
* @param rc request context
* @param wc operation context
* @return MHD queue status
*/
static MHD_RESULT
generate_reply_success (const struct TEH_RequestContext *rc,
const struct BatchWithdrawContext *wc)
{
json_t *sigs;
sigs = json_array ();
GNUNET_assert (NULL != sigs);
for (unsigned int i = 0; iplanchets_length; i++)
{
struct PlanchetContext *pc = &wc->planchets[i];
GNUNET_assert (
0 ==
json_array_append_new (
sigs,
GNUNET_JSON_PACK (
TALER_JSON_pack_blinded_denom_sig (
"ev_sig",
&pc->collectable.sig))));
}
TEH_METRICS_batch_withdraw_num_coins += wc->planchets_length;
return TALER_MHD_REPLY_JSON_PACK (
rc->connection,
MHD_HTTP_OK,
GNUNET_JSON_pack_array_steal ("ev_sigs",
sigs));
}
/**
* Check if the @a rc is replayed and we already have an
* answer. If so, replay the existing answer and return the
* HTTP response.
*
* @param rc request context
* @param wc parsed request data
* @param[out] mret HTTP status, set if we return true
* @return true if the request is idempotent with an existing request
* false if we did not find the request in the DB and did not set @a mret
*/
static bool
check_request_idempotent (const struct TEH_RequestContext *rc,
const struct BatchWithdrawContext *wc,
MHD_RESULT *mret)
{
for (unsigned int i = 0; iplanchets_length; i++)
{
struct PlanchetContext *pc = &wc->planchets[i];
enum GNUNET_DB_QueryStatus qs;
qs = TEH_plugin->get_withdraw_info (TEH_plugin->cls,
&pc->h_coin_envelope,
&pc->collectable);
if (0 > qs)
{
GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);
if (GNUNET_DB_STATUS_HARD_ERROR == qs)
*mret = TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_GENERIC_DB_FETCH_FAILED,
"get_withdraw_info");
return true; /* well, kind-of */
}
if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
return false;
}
/* generate idempotent reply */
TEH_METRICS_num_requests[TEH_MT_REQUEST_IDEMPOTENT_BATCH_WITHDRAW]++;
*mret = generate_reply_success (rc,
wc);
return true;
}
/**
* The request was parsed successfully. Prepare
* our side for the main DB transaction.
*
* @param rc request details
* @param wc storage for request processing
* @return MHD result for the @a rc
*/
static MHD_RESULT
prepare_transaction (const struct TEH_RequestContext *rc,
struct BatchWithdrawContext *wc)
{
/* Note: We could check the reserve balance here,
just to be reasonably sure that the reserve has
a sufficient balance before doing the "expensive"
signatures... */
/* Sign before transaction! */
for (unsigned int i = 0; iplanchets_length; i++)
{
struct PlanchetContext *pc = &wc->planchets[i];
enum TALER_ErrorCode ec;
ec = TEH_keys_denomination_sign_withdraw (
&pc->collectable.denom_pub_hash,
&pc->blinded_planchet,
&pc->collectable.sig);
if (TALER_EC_NONE != ec)
{
GNUNET_break (0);
return TALER_MHD_reply_with_ec (rc->connection,
ec,
NULL);
}
}
/* run transaction */
{
MHD_RESULT mhd_ret;
if (GNUNET_OK !=
TEH_DB_run_transaction (rc->connection,
"run batch withdraw",
TEH_MT_REQUEST_WITHDRAW,
&mhd_ret,
&batch_withdraw_transaction,
wc))
{
return mhd_ret;
}
}
/* return final positive response */
return generate_reply_success (rc,
wc);
}
/**
* Continue processing the request @a rc by parsing the
* @a planchets and then running the transaction.
*
* @param rc request details
* @param wc storage for request processing
* @param planchets array of planchets to parse
* @return MHD result for the @a rc
*/
static MHD_RESULT
parse_planchets (const struct TEH_RequestContext *rc,
struct BatchWithdrawContext *wc,
const json_t *planchets)
{
struct TEH_KeyStateHandle *ksh;
MHD_RESULT mret;
for (unsigned int i = 0; iplanchets_length; i++)
{
struct PlanchetContext *pc = &wc->planchets[i];
struct GNUNET_JSON_Specification ispec[] = {
GNUNET_JSON_spec_fixed_auto ("reserve_sig",
&pc->collectable.reserve_sig),
GNUNET_JSON_spec_fixed_auto ("denom_pub_hash",
&pc->collectable.denom_pub_hash),
TALER_JSON_spec_blinded_planchet ("coin_ev",
&pc->blinded_planchet),
GNUNET_JSON_spec_end ()
};
{
enum GNUNET_GenericReturnValue res;
res = TALER_MHD_parse_json_data (rc->connection,
json_array_get (planchets,
i),
ispec);
if (GNUNET_OK != res)
return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
}
pc->collectable.reserve_pub = *wc->reserve_pub;
for (unsigned int k = 0; kplanchets[k];
if (0 ==
TALER_blinded_planchet_cmp (&kpc->blinded_planchet,
&pc->blinded_planchet))
{
GNUNET_break_op (0);
return TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_BAD_REQUEST,
TALER_EC_GENERIC_PARAMETER_MALFORMED,
"duplicate planchet");
}
}
}
ksh = TEH_keys_get_state ();
if (NULL == ksh)
{
if (! check_request_idempotent (rc,
wc,
&mret))
{
return TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_EXCHANGE_GENERIC_KEYS_MISSING,
NULL);
}
return mret;
}
for (unsigned int i = 0; iplanchets_length; i++)
{
struct PlanchetContext *pc = &wc->planchets[i];
struct TEH_DenominationKey *dk;
dk = TEH_keys_denomination_by_hash2 (ksh,
&pc->collectable.denom_pub_hash,
NULL,
NULL);
if (NULL == dk)
{
if (! check_request_idempotent (rc,
wc,
&mret))
{
return TEH_RESPONSE_reply_unknown_denom_pub_hash (
rc->connection,
&pc->collectable.denom_pub_hash);
}
return mret;
}
if (GNUNET_TIME_absolute_is_past (dk->meta.expire_withdraw.abs_time))
{
/* This denomination is past the expiration time for withdraws */
if (! check_request_idempotent (rc,
wc,
&mret))
{
return TEH_RESPONSE_reply_expired_denom_pub_hash (
rc->connection,
&pc->collectable.denom_pub_hash,
TALER_EC_EXCHANGE_GENERIC_DENOMINATION_EXPIRED,
"WITHDRAW");
}
return mret;
}
if (GNUNET_TIME_absolute_is_future (dk->meta.start.abs_time))
{
/* This denomination is not yet valid, no need to check
for idempotency! */
return TEH_RESPONSE_reply_expired_denom_pub_hash (
rc->connection,
&pc->collectable.denom_pub_hash,
TALER_EC_EXCHANGE_GENERIC_DENOMINATION_VALIDITY_IN_FUTURE,
"WITHDRAW");
}
if (dk->recoup_possible)
{
/* This denomination has been revoked */
if (! check_request_idempotent (rc,
wc,
&mret))
{
return TEH_RESPONSE_reply_expired_denom_pub_hash (
rc->connection,
&pc->collectable.denom_pub_hash,
TALER_EC_EXCHANGE_GENERIC_DENOMINATION_REVOKED,
"WITHDRAW");
}
return mret;
}
if (dk->denom_pub.cipher != pc->blinded_planchet.cipher)
{
/* denomination cipher and blinded planchet cipher not the same */
GNUNET_break_op (0);
return TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_BAD_REQUEST,
TALER_EC_EXCHANGE_GENERIC_CIPHER_MISMATCH,
NULL);
}
if (0 >
TALER_amount_add (&pc->collectable.amount_with_fee,
&dk->meta.value,
&dk->meta.fees.withdraw))
{
GNUNET_break (0);
return TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_EXCHANGE_WITHDRAW_AMOUNT_FEE_OVERFLOW,
NULL);
}
if (0 >
TALER_amount_add (&wc->batch_total,
&wc->batch_total,
&pc->collectable.amount_with_fee))
{
GNUNET_break (0);
return TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_EXCHANGE_WITHDRAW_AMOUNT_FEE_OVERFLOW,
NULL);
}
if (GNUNET_OK !=
TALER_coin_ev_hash (&pc->blinded_planchet,
&pc->collectable.denom_pub_hash,
&pc->collectable.h_coin_envelope))
{
GNUNET_break (0);
return TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE,
NULL);
}
TEH_METRICS_num_verifications[TEH_MT_SIGNATURE_EDDSA]++;
if (GNUNET_OK !=
TALER_wallet_withdraw_verify (&pc->collectable.denom_pub_hash,
&pc->collectable.amount_with_fee,
&pc->collectable.h_coin_envelope,
&pc->collectable.reserve_pub,
&pc->collectable.reserve_sig))
{
GNUNET_break_op (0);
return TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_FORBIDDEN,
TALER_EC_EXCHANGE_WITHDRAW_RESERVE_SIGNATURE_INVALID,
NULL);
}
}
/* everything parsed */
return prepare_transaction (rc,
wc);
}
MHD_RESULT
TEH_handler_batch_withdraw (struct TEH_RequestContext *rc,
const struct TALER_ReservePublicKeyP *reserve_pub,
const json_t *root)
{
struct BatchWithdrawContext wc;
json_t *planchets;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_json ("planchets",
&planchets),
GNUNET_JSON_spec_end ()
};
memset (&wc,
0,
sizeof (wc));
GNUNET_assert (GNUNET_OK ==
TALER_amount_set_zero (TEH_currency,
&wc.batch_total));
wc.reserve_pub = reserve_pub;
{
enum GNUNET_GenericReturnValue res;
res = TALER_MHD_parse_json_data (rc->connection,
root,
spec);
if (GNUNET_OK != res)
return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
}
if ( (! json_is_array (planchets)) ||
(0 == json_array_size (planchets)) )
{
GNUNET_JSON_parse_free (spec);
GNUNET_break_op (0);
return TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_BAD_REQUEST,
TALER_EC_GENERIC_PARAMETER_MALFORMED,
"planchets");
}
wc.planchets_length = json_array_size (planchets);
if (wc.planchets_length > TALER_MAX_FRESH_COINS)
{
GNUNET_JSON_parse_free (spec);
GNUNET_break_op (0);
return TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_BAD_REQUEST,
TALER_EC_GENERIC_PARAMETER_MALFORMED,
"too many planchets");
}
{
struct PlanchetContext splanchets[wc.planchets_length];
MHD_RESULT ret;
memset (splanchets,
0,
sizeof (splanchets));
wc.planchets = splanchets;
ret = parse_planchets (rc,
&wc,
planchets);
/* Clean up */
for (unsigned int i = 0; iblinded_planchet);
TALER_blinded_denom_sig_free (&pc->collectable.sig);
}
GNUNET_JSON_parse_free (spec);
return ret;
}
}
/* end of taler-exchange-httpd_batch-withdraw.c */