diff options
Diffstat (limited to 'src/exchange/taler-exchange-httpd_reserves_open.c')
| -rw-r--r-- | src/exchange/taler-exchange-httpd_reserves_open.c | 471 |
1 files changed, 471 insertions, 0 deletions
diff --git a/src/exchange/taler-exchange-httpd_reserves_open.c b/src/exchange/taler-exchange-httpd_reserves_open.c new file mode 100644 index 000000000..5aadc9e40 --- /dev/null +++ b/src/exchange/taler-exchange-httpd_reserves_open.c @@ -0,0 +1,471 @@ +/* + This file is part of TALER + Copyright (C) 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 <http://www.gnu.org/licenses/> +*/ +/** + * @file taler-exchange-httpd_reserves_open.c + * @brief Handle /reserves/$RESERVE_PUB/open requests + * @author Christian Grothoff + */ +#include "platform.h" +#include <gnunet/gnunet_util_lib.h> +#include <jansson.h> +#include "taler_mhd_lib.h" +#include "taler_json_lib.h" +#include "taler_dbevents.h" +#include "taler-exchange-httpd_common_deposit.h" +#include "taler-exchange-httpd_keys.h" +#include "taler-exchange-httpd_reserves_open.h" +#include "taler-exchange-httpd_responses.h" + + +/** + * How far do we allow a client's time to be off when + * checking the request timestamp? + */ +#define TIMESTAMP_TOLERANCE \ + GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15) + + +/** + * Closure for #reserve_open_transaction. + */ +struct ReserveOpenContext +{ + /** + * Public key of the reserve the inquiry is about. + */ + const struct TALER_ReservePublicKeyP *reserve_pub; + + /** + * Desired (minimum) expiration time for the reserve. + */ + struct GNUNET_TIME_Timestamp desired_expiration; + + /** + * Actual expiration time for the reserve. + */ + struct GNUNET_TIME_Timestamp reserve_expiration; + + /** + * Timestamp of the request. + */ + struct GNUNET_TIME_Timestamp timestamp; + + /** + * Client signature approving the request. + */ + struct TALER_ReserveSignatureP reserve_sig; + + /** + * Global fees applying to the request. + */ + const struct TEH_GlobalFee *gf; + + /** + * Amount to be paid from the reserve. + */ + struct TALER_Amount reserve_payment; + + /** + * Actual cost to open the reserve. + */ + struct TALER_Amount open_cost; + + /** + * Total amount that was deposited. + */ + struct TALER_Amount total; + + /** + * Information about payments by coin. + */ + struct TEH_PurseDepositedCoin *payments; + + /** + * Length of the @e payments array. + */ + unsigned int payments_len; + + /** + * Desired minimum purse limit. + */ + uint32_t purse_limit; + + /** + * Set to true if the reserve balance is too low + * for the operation. + */ + bool no_funds; + +}; + + +/** + * Send reserve open to client. + * + * @param connection connection to the client + * @param rsc reserve open data to return + * @return MHD result code + */ +static MHD_RESULT +reply_reserve_open_success (struct MHD_Connection *connection, + const struct ReserveOpenContext *rsc) +{ + struct GNUNET_TIME_Timestamp now; + struct GNUNET_TIME_Timestamp re; + unsigned int status; + + status = MHD_HTTP_OK; + if (GNUNET_TIME_timestamp_cmp (rsc->reserve_expiration, + <, + rsc->desired_expiration)) + status = MHD_HTTP_PAYMENT_REQUIRED; + now = GNUNET_TIME_timestamp_get (); + if (GNUNET_TIME_timestamp_cmp (rsc->reserve_expiration, + <, + now)) + re = now; + else + re = rsc->reserve_expiration; + return TALER_MHD_REPLY_JSON_PACK ( + connection, + status, + GNUNET_JSON_pack_timestamp ("reserve_expiration", + re), + TALER_JSON_pack_amount ("open_cost", + &rsc->open_cost)); +} + + +/** + * Cleans up information in @a rsc, but does not + * free @a rsc itself (allocated on the stack!). + * + * @param[in] rsc struct with information to clean up + */ +static void +cleanup_rsc (struct ReserveOpenContext *rsc) +{ + for (unsigned int i = 0; i<rsc->payments_len; i++) + { + TEH_common_purse_deposit_free_coin (&rsc->payments[i]); + } + GNUNET_free (rsc->payments); +} + + +/** + * Function implementing /reserves/$RID/open transaction. Given the public + * key of a reserve, return the associated transaction open. 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 ReserveOpenContext *` + * @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 +reserve_open_transaction (void *cls, + struct MHD_Connection *connection, + MHD_RESULT *mhd_ret) +{ + struct ReserveOpenContext *rsc = cls; + enum GNUNET_DB_QueryStatus qs; + struct TALER_Amount reserve_balance; + + for (unsigned int i = 0; i<rsc->payments_len; i++) + { + struct TEH_PurseDepositedCoin *coin = &rsc->payments[i]; + bool insufficient_funds = true; + + GNUNET_log (GNUNET_ERROR_TYPE_INFO, + "Make coin %u known\n", + i); + qs = TEH_make_coin_known (&coin->cpi, + connection, + &coin->known_coin_id, + mhd_ret); + if (qs < 0) + return qs; + GNUNET_log (GNUNET_ERROR_TYPE_INFO, + "Insert open deposit %u known\n", + i); + qs = TEH_plugin->insert_reserve_open_deposit ( + TEH_plugin->cls, + &coin->cpi, + &coin->coin_sig, + coin->known_coin_id, + &coin->amount, + &rsc->reserve_sig, + rsc->reserve_pub, + &insufficient_funds); + /* 0 == qs is fine, then the coin was already + spent for this very operation as identified + by reserve_sig! */ + if (qs < 0) + { + if (GNUNET_DB_STATUS_SOFT_ERROR == qs) + return qs; + GNUNET_break (0); + *mhd_ret = TALER_MHD_reply_with_error (connection, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TALER_EC_GENERIC_DB_STORE_FAILED, + "insert_reserve_open_deposit"); + return qs; + } + if (insufficient_funds) + { + GNUNET_log (GNUNET_ERROR_TYPE_INFO, + "Handle insufficient funds\n"); + *mhd_ret + = TEH_RESPONSE_reply_coin_insufficient_funds ( + connection, + TALER_EC_EXCHANGE_GENERIC_INSUFFICIENT_FUNDS, + &coin->cpi.denom_pub_hash, + &coin->cpi.coin_pub); + return GNUNET_DB_STATUS_HARD_ERROR; + } + } + + GNUNET_log (GNUNET_ERROR_TYPE_INFO, + "Do reserve open with reserve payment of %s\n", + TALER_amount2s (&rsc->total)); + qs = TEH_plugin->do_reserve_open (TEH_plugin->cls, + /* inputs */ + rsc->reserve_pub, + &rsc->total, + &rsc->reserve_payment, + rsc->purse_limit, + &rsc->reserve_sig, + rsc->desired_expiration, + rsc->timestamp, + &rsc->gf->fees.account, + /* outputs */ + &rsc->no_funds, + &reserve_balance, + &rsc->open_cost, + &rsc->reserve_expiration); + switch (qs) + { + case GNUNET_DB_STATUS_HARD_ERROR: + GNUNET_break (0); + *mhd_ret + = TALER_MHD_reply_with_error (connection, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TALER_EC_GENERIC_DB_FETCH_FAILED, + "do_reserve_open"); + return GNUNET_DB_STATUS_HARD_ERROR; + case GNUNET_DB_STATUS_SOFT_ERROR: + return qs; + case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS: + *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; + case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT: + break; + } + if (rsc->no_funds) + { + TEH_plugin->rollback (TEH_plugin->cls); + *mhd_ret + = TEH_RESPONSE_reply_reserve_insufficient_balance ( + connection, + TALER_EC_EXCHANGE_RESERVES_OPEN_INSUFFICIENT_FUNDS, + &reserve_balance, + &rsc->reserve_payment, + rsc->reserve_pub); + return GNUNET_DB_STATUS_HARD_ERROR; + } + return qs; +} + + +MHD_RESULT +TEH_handler_reserves_open (struct TEH_RequestContext *rc, + const struct TALER_ReservePublicKeyP *reserve_pub, + const json_t *root) +{ + struct ReserveOpenContext rsc; + const json_t *payments; + struct GNUNET_JSON_Specification spec[] = { + GNUNET_JSON_spec_timestamp ("request_timestamp", + &rsc.timestamp), + GNUNET_JSON_spec_timestamp ("reserve_expiration", + &rsc.desired_expiration), + GNUNET_JSON_spec_fixed_auto ("reserve_sig", + &rsc.reserve_sig), + GNUNET_JSON_spec_uint32 ("purse_limit", + &rsc.purse_limit), + GNUNET_JSON_spec_array_const ("payments", + &payments), + TALER_JSON_spec_amount ("reserve_payment", + TEH_currency, + &rsc.reserve_payment), + GNUNET_JSON_spec_end () + }; + + rsc.reserve_pub = reserve_pub; + { + enum GNUNET_GenericReturnValue res; + + res = TALER_MHD_parse_json_data (rc->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 */ + } + } + + { + struct GNUNET_TIME_Timestamp now; + + now = GNUNET_TIME_timestamp_get (); + if (! GNUNET_TIME_absolute_approx_eq (now.abs_time, + rsc.timestamp.abs_time, + TIMESTAMP_TOLERANCE)) + { + GNUNET_break_op (0); + return TALER_MHD_reply_with_error (rc->connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_EXCHANGE_GENERIC_CLOCK_SKEW, + NULL); + } + } + + rsc.payments_len = json_array_size (payments); + rsc.payments = GNUNET_new_array (rsc.payments_len, + struct TEH_PurseDepositedCoin); + rsc.total = rsc.reserve_payment; + for (unsigned int i = 0; i<rsc.payments_len; i++) + { + struct TEH_PurseDepositedCoin *coin = &rsc.payments[i]; + enum GNUNET_GenericReturnValue res; + + res = TEH_common_purse_deposit_parse_coin ( + rc->connection, + coin, + json_array_get (payments, + i)); + if (GNUNET_SYSERR == res) + { + GNUNET_break (0); + cleanup_rsc (&rsc); + return MHD_NO; /* hard failure */ + } + if (GNUNET_NO == res) + { + GNUNET_break_op (0); + cleanup_rsc (&rsc); + return MHD_YES; /* failure */ + } + if (0 > + TALER_amount_add (&rsc.total, + &rsc.total, + &coin->amount_minus_fee)) + { + GNUNET_break (0); + cleanup_rsc (&rsc); + return TALER_MHD_reply_with_error (rc->connection, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TALER_EC_GENERIC_FAILED_COMPUTE_AMOUNT, + NULL); + } + } + + { + struct TEH_KeyStateHandle *keys; + + keys = TEH_keys_get_state (); + if (NULL == keys) + { + GNUNET_break (0); + cleanup_rsc (&rsc); + return TALER_MHD_reply_with_error (rc->connection, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TALER_EC_EXCHANGE_GENERIC_KEYS_MISSING, + NULL); + } + rsc.gf = TEH_keys_global_fee_by_time (keys, + rsc.timestamp); + } + if (NULL == rsc.gf) + { + GNUNET_break (0); + cleanup_rsc (&rsc); + return TALER_MHD_reply_with_error (rc->connection, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TALER_EC_EXCHANGE_GENERIC_BAD_CONFIGURATION, + NULL); + } + + if (GNUNET_OK != + TALER_wallet_reserve_open_verify (&rsc.reserve_payment, + rsc.timestamp, + rsc.desired_expiration, + rsc.purse_limit, + reserve_pub, + &rsc.reserve_sig)) + { + GNUNET_break_op (0); + cleanup_rsc (&rsc); + return TALER_MHD_reply_with_error (rc->connection, + MHD_HTTP_FORBIDDEN, + TALER_EC_EXCHANGE_RESERVES_OPEN_BAD_SIGNATURE, + NULL); + } + + { + MHD_RESULT mhd_ret; + + if (GNUNET_OK != + TEH_DB_run_transaction (rc->connection, + "reserve open", + TEH_MT_REQUEST_OTHER, + &mhd_ret, + &reserve_open_transaction, + &rsc)) + { + cleanup_rsc (&rsc); + return mhd_ret; + } + } + + { + MHD_RESULT mhd_ret; + + mhd_ret = reply_reserve_open_success (rc->connection, + &rsc); + cleanup_rsc (&rsc); + return mhd_ret; + } +} + + +/* end of taler-exchange-httpd_reserves_open.c */ |