From bdc4482ac675bc7e58e017523a8d4f5ed80d8dee Mon Sep 17 00:00:00 2001 From: Christian Grothoff Date: Wed, 29 Jun 2022 14:39:45 +0200 Subject: first skeleton for batch deposits --- src/exchange/taler-exchange-httpd_batch-deposit.c | 610 ++++++++++++++++++++++ 1 file changed, 610 insertions(+) create mode 100644 src/exchange/taler-exchange-httpd_batch-deposit.c (limited to 'src/exchange/taler-exchange-httpd_batch-deposit.c') diff --git a/src/exchange/taler-exchange-httpd_batch-deposit.c b/src/exchange/taler-exchange-httpd_batch-deposit.c new file mode 100644 index 000000000..10047f598 --- /dev/null +++ b/src/exchange/taler-exchange-httpd_batch-deposit.c @@ -0,0 +1,610 @@ +/* + 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-deposit.c + * @brief Handle /batch-deposit requests; parses the POST and JSON and + * verifies the coin signatures 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_exchangedb_lib.h" +#include "taler-exchange-httpd_keys.h" + + +/** + * Closure for #batch_deposit_transaction. + */ +struct BatchDepositContext +{ + /** + * Information about the individual coin deposits. + */ + struct TALER_EXCHANGEDB_Deposit *deposits; + + /** + * Our timestamp (when we received the request). + * Possibly updated by the transaction if the + * request is idempotent (was repeated). + */ + struct GNUNET_TIME_Timestamp exchange_timestamp; + + /** + * Hash over the proposal data between merchant and customer + * (remains unknown to the Exchange). + */ + struct TALER_PrivateContractHashP h_contract_terms; + + /** + * Public key of the merchant. Enables later identification + * of the merchant in case of a need to rollback transactions. + */ + struct TALER_MerchantPublicKeyP merchant_pub; + + /** + * Salt used by the merchant to compute "h_wire". + */ + struct TALER_WireSaltP wire_salt; + + /** + * Hash of the payto URI. + */ + struct TALER_PaytoHashP h_payto; + + /** + * Information about the receiver for executing the transaction. URI in + * payto://-format. + */ + const char *payto_uri; + + /** + * Additional details for extensions relevant for this + * deposit operation, possibly NULL! + */ + json_t *extension_details; + + /** + * Time when this request was generated. Used, for example, to + * assess when (roughly) the income was achieved for tax purposes. + * Note that the Exchange will only check that the timestamp is not "too + * far" into the future (i.e. several days). The fact that the + * timestamp falls within the validity period of the coin's + * denomination key is irrelevant for the validity of the deposit + * request, as obviously the customer and merchant could conspire to + * set any timestamp. Also, the Exchange must accept very old deposit + * requests, as the merchant might have been unable to transmit the + * deposit request in a timely fashion (so back-dating is not + * prevented). + */ + struct GNUNET_TIME_Timestamp timestamp; + + /** + * How much time does the merchant have to issue a refund request? + * Zero if refunds are not allowed. After this time, the coin + * cannot be refunded. + */ + struct GNUNET_TIME_Timestamp refund_deadline; + + /** + * How much time does the merchant have to execute the wire transfer? + * This time is advisory for aggregating transactions, not a hard + * constraint (as the merchant can theoretically pick any time, + * including one in the past). + */ + struct GNUNET_TIME_Timestamp wire_deadline; + + /** + * Number of coins in the batch. + */ + unsigned int num_coins; +}; + + +/** + * Send confirmation of batch 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 coins had sufficient + * (residual) value for the specified transaction and that it will execute the + * requested batch deposit operation with the given wiring details. + * + * @param connection connection to the client + * @param bdc information about the batch deposit + * @return MHD result code + */ +static MHD_RESULT +reply_batch_deposit ( + struct MHD_Connection *connection, + const struct BatchDepositContext *bdc) +{ + struct TALER_ExchangePublicKeyP pub; + struct TALER_ExchangeSignatureP sig; + enum TALER_ErrorCode ec; + +#if FIXME + if (TALER_EC_NONE != + (ec = TALER_exchange_online_deposit_confirmation_sign ( + &TEH_keys_exchange_sign_, + h_contract_terms, + h_wire, + h_extensions, + exchange_timestamp, + wire_deadline, + refund_deadline, + amount_without_fee, + coin_pub, + merchant, + &pub, + &sig))) + { + return TALER_MHD_reply_with_ec (connection, + ec, + NULL); + } +#endif + return TALER_MHD_REPLY_JSON_PACK ( + connection, + MHD_HTTP_OK, + GNUNET_JSON_pack_timestamp ("exchange_timestamp", + exchange_timestamp), + GNUNET_JSON_pack_data_auto ("exchange_sig", + &sig), + GNUNET_JSON_pack_data_auto ("exchange_pub", + &pub)); +} + + +/** + * 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 BatchDepositContext` + * @param connection MHD request context + * @param[out] mhd_ret set to MHD status on error + * @return transaction status + */ +static enum GNUNET_DB_QueryStatus +batch_deposit_transaction (void *cls, + struct MHD_Connection *connection, + MHD_RESULT *mhd_ret) +{ + struct BatchDepositContext *dc = cls; + enum GNUNET_DB_QueryStatus qs; + bool balance_ok; + bool in_conflict; + + for (unsigned int i = 0; inum_coins; i++) + { + uint64_t known_coin_id; + + qs = TEH_make_coin_known (&dc->deposit->coin, + connection, + &dc->known_coin_id, + mhd_ret); + if (qs < 0) + return qs; + qs = TEH_plugin->do_deposit (TEH_plugin->cls, + dc->deposit, + dc->known_coin_id, + &dc->h_payto, + false, /* FIXME-OEC: extension blocked */ + &dc->exchange_timestamp, + &balance_ok, + &in_conflict); + if (qs < 0) + { + if (GNUNET_DB_STATUS_SOFT_ERROR == qs) + return 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_GENERIC_DB_STORE_FAILED, + "deposit"); + return qs; + } + if (in_conflict) + { + /* FIXME: conficting contract != insufficient funds */ + *mhd_ret + = TEH_RESPONSE_reply_coin_insufficient_funds ( + connection, + TALER_EC_EXCHANGE_DEPOSIT_CONFLICTING_CONTRACT, + &dc->deposit->coin.denom_pub_hash, + &dc->deposit->coin.coin_pub); + return GNUNET_DB_STATUS_HARD_ERROR; + } + if (! balance_ok) + { + *mhd_ret + = TEH_RESPONSE_reply_coin_insufficient_funds ( + connection, + TALER_EC_EXCHANGE_GENERIC_INSUFFICIENT_FUNDS, + &dc->deposit->coin.denom_pub_hash, + &dc->deposit->coin.coin_pub); + return GNUNET_DB_STATUS_HARD_ERROR; + } + } + TEH_METRICS_num_success[TEH_MT_SUCCESS_DEPOSIT]++; + return qs; +} + + +/** + * Parse per-coin deposit information from @a jcoin + * into @a deposit. Fill in generic information from + * @a ctx. + * + * @param connection connection we are handling + * @param jcoin coin data to parse + * @param ctx overall context information to use + * @param[out] deposit where to store the result + * @return #GNUNET_OK on success, #GNUNET_NO if an error was returned, + * #GNUNET_SYSERR on failure and no error could be returned + */ +static enum GNUNET_GenericReturnValue +parse_coin (struct MHD_Connection *connection, + json_t *jcoin, + const struct BatchDepositContext *ctx, + struct TALER_EXCHANGEDB_Deposit *deposit) +{ + struct GNUNET_JSON_Specification spec[] = { + TALER_JSON_spec_amount ("contribution", + TEH_currency, + &deposit.amount_with_fee), + GNUNET_JSON_spec_fixed_auto ("denom_pub_hash", + &deposit.coin.denom_pub_hash), + TALER_JSON_spec_denom_sig ("ub_sig", + &deposit.coin.denom_sig), + GNUNET_JSON_spec_fixed_auto ("coin_pub", + &deposit.coin_pub), + GNUNET_JSON_spec_mark_optional ( + GNUNET_JSON_spec_fixed_auto ("h_age_commitment", + &deposit.coin.h_age_commitment), + &deposit.coin.no_age_commitment), + GNUNET_JSON_spec_fixed_auto ("coin_sig", + &deposit.csig), + GNUNET_JSON_spec_end () + }; + enum GNUNET_GenericReturnValue 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 */ + } + + /* check denomination exists and is valid */ + { + struct TEH_DenominationKey *dk; + MHD_RESULT mret; + + dk = TEH_keys_denomination_by_hash (&deposit.coin.denom_pub_hash, + connection, + &mret); + if (NULL == dk) + { + GNUNET_JSON_parse_free (spec); + return mret; + } + if (0 > TALER_amount_cmp (&dk->meta.value, + &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_EXCHANGE_GENERIC_AMOUNT_EXCEEDS_DENOMINATION_VALUE, + NULL); + } + if (GNUNET_TIME_absolute_is_past (dk->meta.expire_deposit.abs_time)) + { + /* This denomination is past the expiration time for deposits */ + GNUNET_JSON_parse_free (spec); + return TEH_RESPONSE_reply_expired_denom_pub_hash ( + connection, + &deposit.coin.denom_pub_hash, + TALER_EC_EXCHANGE_GENERIC_DENOMINATION_EXPIRED, + "DEPOSIT"); + } + if (GNUNET_TIME_absolute_is_future (dk->meta.start.abs_time)) + { + /* This denomination is not yet valid */ + GNUNET_JSON_parse_free (spec); + return TEH_RESPONSE_reply_expired_denom_pub_hash ( + connection, + &deposit.coin.denom_pub_hash, + TALER_EC_EXCHANGE_GENERIC_DENOMINATION_VALIDITY_IN_FUTURE, + "DEPOSIT"); + } + if (dk->recoup_possible) + { + /* This denomination has been revoked */ + GNUNET_JSON_parse_free (spec); + return TEH_RESPONSE_reply_expired_denom_pub_hash ( + connection, + &deposit.coin.denom_pub_hash, + TALER_EC_EXCHANGE_GENERIC_DENOMINATION_REVOKED, + "DEPOSIT"); + } + if (dk->denom_pub.cipher != deposit.coin.denom_sig.cipher) + { + /* denomination cipher and denomination signature cipher not the same */ + GNUNET_JSON_parse_free (spec); + return TALER_MHD_reply_with_error (connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_EXCHANGE_GENERIC_CIPHER_MISMATCH, + NULL); + } + + deposit.deposit_fee = dk->meta.fees.deposit; + /* check coin signature */ + switch (dk->denom_pub.cipher) + { + case TALER_DENOMINATION_RSA: + TEH_METRICS_num_verifications[TEH_MT_SIGNATURE_RSA]++; + break; + case TALER_DENOMINATION_CS: + TEH_METRICS_num_verifications[TEH_MT_SIGNATURE_CS]++; + break; + default: + break; + } + if (GNUNET_YES != + TALER_test_coin_valid (&deposit.coin, + &dk->denom_pub)) + { + TALER_LOG_WARNING ("Invalid coin passed for /deposit\n"); + GNUNET_JSON_parse_free (spec); + return TALER_MHD_reply_with_error (connection, + MHD_HTTP_FORBIDDEN, + TALER_EC_EXCHANGE_DENOMINATION_SIGNATURE_INVALID, + NULL); + } + } + 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_EXCHANGE_DEPOSIT_NEGATIVE_VALUE_AFTER_FEE, + NULL); + } + + TEH_METRICS_num_verifications[TEH_MT_SIGNATURE_EDDSA]++; + if (GNUNET_OK != + TALER_wallet_deposit_verify (&deposit.amount_with_fee, + &deposit.deposit_fee, + &h_wire, + &deposit.h_contract_terms, + &deposit.coin.h_age_commitment, + NULL /* h_extensions! */, + &deposit.coin.denom_pub_hash, + deposit.timestamp, + &deposit.merchant_pub, + deposit.refund_deadline, + &deposit.coin.coin_pub, + &deposit.csig)) + { + TALER_LOG_WARNING ("Invalid signature on /deposit request\n"); + GNUNET_JSON_parse_free (spec); + return TALER_MHD_reply_with_error (connection, + MHD_HTTP_FORBIDDEN, + TALER_EC_EXCHANGE_DEPOSIT_COIN_SIGNATURE_INVALID, + NULL); + } + + // FIXME: duplicate batch-global values into + // per-deposit data structure! + return GNUNET_OK; +} + + +MHD_RESULT +TEH_handler_batch_deposit (struct MHD_Connection *connection, + const json_t *root) +{ + struct BatchDepositContext dc; + json_t *coins; + bool no_refund_deadline = true; + struct GNUNET_JSON_Specification spec[] = { + GNUNET_JSON_spec_string ("merchant_payto_uri", + &dc.payto_uri), + GNUNET_JSON_spec_fixed_auto ("wire_salt", + &dc.wire_salt), + GNUNET_JSON_spec_fixed_auto ("merchant_pub", + &dc.merchant_pub), + GNUNET_JSON_spec_fixed_auto ("h_contract_terms", + &dc.h_contract_terms), + GNUNET_JSON_spec_json ("coins", + &coins), + GNUNET_JSON_spec_timestamp ("timestamp", + &dc.timestamp), + GNUNET_JSON_spec_mark_optional ( + GNUNET_JSON_spec_timestamp ("refund_deadline", + &dc.refund_deadline), + &no_refund_deadline), + GNUNET_JSON_spec_timestamp ("wire_transfer_deadline", + &dc.wire_deadline), + GNUNET_JSON_spec_end () + }; + + struct TALER_MerchantWireHashP h_wire; + enum GNUNET_GenericReturnValue 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 */ + } + + /* validate merchant's wire details (as far as we can) */ + { + char *emsg; + + emsg = TALER_payto_validate (dc.payto_uri); + if (NULL != emsg) + { + MHD_RESULT ret; + + GNUNET_break_op (0); + GNUNET_JSON_parse_free (spec); + ret = TALER_MHD_reply_with_error (connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_GENERIC_PARAMETER_MALFORMED, + emsg); + GNUNET_free (emsg); + return ret; + } + } + if (GNUNET_TIME_timestamp_cmp (deposit.refund_deadline, + >, + deposit.wire_deadline)) + { + GNUNET_break_op (0); + GNUNET_JSON_parse_free (spec); + return TALER_MHD_reply_with_error (connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_EXCHANGE_DEPOSIT_REFUND_DEADLINE_AFTER_WIRE_DEADLINE, + NULL); + } + if (GNUNET_TIME_absolute_is_never (deposit.wire_deadline.abs_time)) + { + GNUNET_break_op (0); + GNUNET_JSON_parse_free (spec); + return TALER_MHD_reply_with_error (connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_EXCHANGE_DEPOSIT_WIRE_DEADLINE_IS_NEVER, + NULL); + } + TALER_payto_hash (dc.payto_uri, + &dc.h_payto); + TALER_merchant_wire_signature_hash (dc.payto_uri, + &deposit.wire_salt, + &h_wire); + dc.num_coins = json_array_size (coins); + if (0 == dc.num_coins) + { + GNUNET_break_op (0); + return TALER_MHD_reply_with_error (connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_GENERIC_PARAMETER_MALFORMED, + "coins"); + } + if (TALER_MAX_FRESH_COINS < dc.num_coins) + { + GNUNET_break_op (0); + return TALER_MHD_reply_with_error (connection, + MHD_HTTP_BAD_REQUEST, + TALER_EC_GENERIC_PARAMETER_MALFORMED, + "coins"); + } + dc->deposits = GNUNET_new_array (dc.num_coins, + struct TALER_EXCHANGEDB_Deposit *); + for (unsigned int i = 0; ideposits[i]))) + { + for (unsigned int j = 0; jpreflight (TEH_plugin->cls)) + { + GNUNET_break (0); + return TALER_MHD_reply_with_error (connection, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TALER_EC_GENERIC_DB_START_FAILED, + "preflight failure"); + } + + /* execute transaction */ + { + MHD_RESULT mhd_ret; + + if (GNUNET_OK != + TEH_DB_run_transaction (connection, + "execute batch deposit", + TEH_MT_REQUEST_BATCH_DEPOSIT, + &mhd_ret, + &batch_deposit_transaction, + &dc)) + { + GNUNET_JSON_parse_free (spec); + for (unsigned int j = 0; j