diff options
Diffstat (limited to 'src/lib/exchange_api_deposit.c')
| -rw-r--r-- | src/lib/exchange_api_deposit.c | 727 |
1 files changed, 0 insertions, 727 deletions
diff --git a/src/lib/exchange_api_deposit.c b/src/lib/exchange_api_deposit.c deleted file mode 100644 index 54dad7473..000000000 --- a/src/lib/exchange_api_deposit.c +++ /dev/null @@ -1,727 +0,0 @@ -/* - 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 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 General Public License for more details. - - You should have received a copy of the GNU General Public License along with - TALER; see the file COPYING. If not, see - <http://www.gnu.org/licenses/> -*/ -/** - * @file lib/exchange_api_deposit.c - * @brief Implementation of the /deposit request of the exchange's HTTP API - * @author Sree Harsha Totakura <sreeharsha@totakura.in> - * @author Christian Grothoff - */ -#include "platform.h" -#include <jansson.h> -#include <microhttpd.h> /* just for HTTP status codes */ -#include <gnunet/gnunet_util_lib.h> -#include <gnunet/gnunet_json_lib.h> -#include <gnunet/gnunet_curl_lib.h> -#include "taler_json_lib.h" -#include "taler_auditor_service.h" -#include "taler_exchange_service.h" -#include "exchange_api_handle.h" -#include "taler_signatures.h" -#include "exchange_api_curl_defaults.h" - - -/** - * 1:#AUDITOR_CHANCE is the probability that we report deposits - * to the auditor. - * - * 20==5% of going to auditor. This is possibly still too high, but set - * deliberately this high for testing - */ -#define AUDITOR_CHANCE 20 - -/** - * @brief A Deposit Handle - */ -struct TALER_EXCHANGE_DepositHandle -{ - - /** - * The connection to exchange this request handle will use - */ - struct TALER_EXCHANGE_Handle *exchange; - - /** - * The url for this request. - */ - char *url; - - /** - * Context for #TEH_curl_easy_post(). Keeps the data that must - * persist for Curl to make the upload. - */ - struct TALER_CURL_PostContext ctx; - - /** - * Handle for the request. - */ - struct GNUNET_CURL_Job *job; - - /** - * Function to call with the result. - */ - TALER_EXCHANGE_DepositResultCallback cb; - - /** - * Closure for @a cb. - */ - void *cb_cls; - - /** - * Information the exchange should sign in response. - */ - struct TALER_DepositConfirmationPS depconf; - - /** - * Exchange signature, set for #auditor_cb. - */ - struct TALER_ExchangeSignatureP exchange_sig; - - /** - * Exchange signing public key, set for #auditor_cb. - */ - struct TALER_ExchangePublicKeyP exchange_pub; - - /** - * Value of the /deposit transaction, including fee. - */ - struct TALER_Amount amount_with_fee; - - /** - * @brief Public information about the coin's denomination key. - * Note that the "key" field itself has been zero'ed out. - */ - struct TALER_EXCHANGE_DenomPublicKey dki; - - /** - * Chance that we will inform the auditor about the deposit - * is 1:n, where the value of this field is "n". - */ - unsigned int auditor_chance; - -}; - - -/** - * Function called for each auditor to give us a chance to possibly - * launch a deposit confirmation interaction. - * - * @param cls closure - * @param ah handle to the auditor - * @param auditor_pub public key of the auditor - * @return NULL if no deposit confirmation interaction was launched - */ -static struct TEAH_AuditorInteractionEntry * -auditor_cb (void *cls, - struct TALER_AUDITOR_Handle *ah, - const struct TALER_AuditorPublicKeyP *auditor_pub) -{ - struct TALER_EXCHANGE_DepositHandle *dh = cls; - const struct TALER_EXCHANGE_Keys *key_state; - const struct TALER_EXCHANGE_SigningPublicKey *spk; - struct TALER_Amount amount_without_fee; - struct TEAH_AuditorInteractionEntry *aie; - - if (0 != GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, - dh->auditor_chance)) - { - GNUNET_log (GNUNET_ERROR_TYPE_INFO, - "Not providing deposit confirmation to auditor\n"); - return NULL; - } - GNUNET_log (GNUNET_ERROR_TYPE_INFO, - "Will provide deposit confirmation to auditor `%s'\n", - TALER_B2S (auditor_pub)); - key_state = TALER_EXCHANGE_get_keys (dh->exchange); - spk = TALER_EXCHANGE_get_signing_key_info (key_state, - &dh->exchange_pub); - if (NULL == spk) - { - GNUNET_break_op (0); - return NULL; - } - TALER_amount_ntoh (&amount_without_fee, - &dh->depconf.amount_without_fee); - aie = GNUNET_new (struct TEAH_AuditorInteractionEntry); - aie->dch = TALER_AUDITOR_deposit_confirmation (ah, - &dh->depconf.h_wire, - &dh->depconf.h_contract_terms, - GNUNET_TIME_absolute_ntoh ( - dh->depconf.timestamp), - GNUNET_TIME_absolute_ntoh ( - dh->depconf.refund_deadline), - &amount_without_fee, - &dh->depconf.coin_pub, - &dh->depconf.merchant, - &dh->exchange_pub, - &dh->exchange_sig, - &key_state->master_pub, - spk->valid_from, - spk->valid_until, - spk->valid_legal, - &spk->master_sig, - &TEAH_acc_confirmation_cb, - aie); - return aie; -} - - -/** - * Verify that the signature on the "200 OK" response - * from the exchange is valid. - * - * @param dh deposit handle - * @param json json reply with the signature - * @param[out] exchange_sig set to the exchange's signature - * @param[out] exchange_pub set to the exchange's public key - * @return #GNUNET_OK if the signature is valid, #GNUNET_SYSERR if not - */ -static int -verify_deposit_signature_ok (struct TALER_EXCHANGE_DepositHandle *dh, - const json_t *json, - struct TALER_ExchangeSignatureP *exchange_sig, - struct TALER_ExchangePublicKeyP *exchange_pub) -{ - const struct TALER_EXCHANGE_Keys *key_state; - struct GNUNET_JSON_Specification spec[] = { - GNUNET_JSON_spec_fixed_auto ("sig", exchange_sig), - GNUNET_JSON_spec_fixed_auto ("pub", exchange_pub), - GNUNET_JSON_spec_end () - }; - - if (GNUNET_OK != - GNUNET_JSON_parse (json, - spec, - NULL, NULL)) - { - GNUNET_break_op (0); - return GNUNET_SYSERR; - } - key_state = TALER_EXCHANGE_get_keys (dh->exchange); - if (GNUNET_OK != - TALER_EXCHANGE_test_signing_key (key_state, - exchange_pub)) - { - GNUNET_break_op (0); - return GNUNET_SYSERR; - } - if (GNUNET_OK != - GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_EXCHANGE_CONFIRM_DEPOSIT, - &dh->depconf.purpose, - &exchange_sig->eddsa_signature, - &exchange_pub->eddsa_pub)) - { - GNUNET_break_op (0); - return GNUNET_SYSERR; - } - dh->exchange_sig = *exchange_sig; - dh->exchange_pub = *exchange_pub; - TEAH_get_auditors_for_dc (dh->exchange, - &auditor_cb, - dh); - return GNUNET_OK; -} - - -/** - * Verify that the signatures on the "403 FORBIDDEN" response from the - * exchange demonstrating customer double-spending are valid. - * - * @param dh deposit handle - * @param json json reply with the signature(s) and transaction history - * @return #GNUNET_OK if the signature(s) is valid, #GNUNET_SYSERR if not - */ -static int -verify_deposit_signature_forbidden ( - const struct TALER_EXCHANGE_DepositHandle *dh, - const json_t *json) -{ - json_t *history; - struct TALER_Amount total; - - history = json_object_get (json, - "history"); - if (GNUNET_OK != - TALER_EXCHANGE_verify_coin_history (&dh->dki, - dh->dki.value.currency, - &dh->depconf.coin_pub, - history, - &total)) - { - GNUNET_break_op (0); - return GNUNET_SYSERR; - } - if (GNUNET_OK != - TALER_amount_add (&total, - &total, - &dh->amount_with_fee)) - { - /* clearly not OK if our transaction would have caused - the overflow... */ - return GNUNET_OK; - } - - if (0 >= TALER_amount_cmp (&total, - &dh->dki.value)) - { - /* transaction should have still fit */ - GNUNET_break (0); - return GNUNET_SYSERR; - } - /* everything OK, proof of double-spending was provided */ - return GNUNET_OK; -} - - -/** - * Function called when we're done processing the - * HTTP /deposit request. - * - * @param cls the `struct TALER_EXCHANGE_DepositHandle` - * @param response_code HTTP response code, 0 on error - * @param response parsed JSON result, NULL on error - */ -static void -handle_deposit_finished (void *cls, - long response_code, - const void *response) -{ - struct TALER_EXCHANGE_DepositHandle *dh = cls; - struct TALER_ExchangeSignatureP exchange_sig; - struct TALER_ExchangePublicKeyP exchange_pub; - struct TALER_ExchangeSignatureP *es = NULL; - struct TALER_ExchangePublicKeyP *ep = NULL; - const json_t *j = response; - enum TALER_ErrorCode ec; - - dh->job = NULL; - switch (response_code) - { - case 0: - ec = TALER_EC_INVALID_RESPONSE; - break; - case MHD_HTTP_OK: - if (GNUNET_OK != - verify_deposit_signature_ok (dh, - j, - &exchange_sig, - &exchange_pub)) - { - GNUNET_break_op (0); - response_code = 0; - ec = TALER_EC_DEPOSIT_INVALID_SIGNATURE_BY_EXCHANGE; - } - else - { - es = &exchange_sig; - ep = &exchange_pub; - ec = TALER_EC_NONE; - } - break; - case MHD_HTTP_BAD_REQUEST: - /* This should never happen, either us or the exchange is buggy - (or API version conflict); just pass JSON reply to the application */ - ec = TALER_JSON_get_error_code (j); - break; - case MHD_HTTP_CONFLICT: - /* Double spending; check signatures on transaction history */ - ec = TALER_JSON_get_error_code (j); - if (GNUNET_OK != - verify_deposit_signature_forbidden (dh, - j)) - { - GNUNET_break_op (0); - response_code = 0; - ec = TALER_EC_DEPOSIT_INVALID_SIGNATURE_BY_EXCHANGE; - } - break; - case MHD_HTTP_FORBIDDEN: - ec = TALER_JSON_get_error_code (j); - /* Nothing really to verify, exchange says one of the signatures is - invalid; as we checked them, this should never happen, we - should pass the JSON reply to the application */ - break; - case MHD_HTTP_NOT_FOUND: - ec = TALER_JSON_get_error_code (j); - /* Nothing really to verify, this should never - happen, we should pass the JSON reply to the application */ - break; - case MHD_HTTP_INTERNAL_SERVER_ERROR: - ec = TALER_JSON_get_error_code (j); - /* Server had an internal issue; we should retry, but this API - leaves this to the application */ - break; - default: - /* unexpected response code */ - ec = TALER_JSON_get_error_code (j); - GNUNET_log (GNUNET_ERROR_TYPE_ERROR, - "Unexpected response code %u/%d\n", - (unsigned int) response_code, - ec); - GNUNET_break (0); - response_code = 0; - break; - } - dh->cb (dh->cb_cls, - response_code, - ec, - es, - ep, - j); - TALER_EXCHANGE_deposit_cancel (dh); -} - - -/** - * Verify signature information about the deposit. - * - * @param dki public key information - * @param amount the amount to be deposited - * @param h_wire hash of the merchant’s account details - * @param h_contract_terms hash of the contact of the merchant with the customer (further details are never disclosed to the exchange) - * @param coin_pub coin’s public key - * @param denom_pub denomination key with which the coin is signed - * @param denom_pub_hash hash of @a denom_pub - * @param denom_sig exchange’s unblinded signature of the coin - * @param timestamp timestamp when the deposit was finalized - * @param merchant_pub the public key of the merchant (used to identify the merchant for refund requests) - * @param refund_deadline date until which the merchant can issue a refund to the customer via the exchange (can be zero if refunds are not allowed) - * @param coin_sig the signature made with purpose #TALER_SIGNATURE_WALLET_COIN_DEPOSIT made by the customer with the coin’s private key. - * @return #GNUNET_OK if signatures are OK, #GNUNET_SYSERR if not - */ -static int -verify_signatures (const struct TALER_EXCHANGE_DenomPublicKey *dki, - const struct TALER_Amount *amount, - const struct GNUNET_HashCode *h_wire, - const struct GNUNET_HashCode *h_contract_terms, - const struct TALER_CoinSpendPublicKeyP *coin_pub, - const struct TALER_DenominationSignature *denom_sig, - const struct TALER_DenominationPublicKey *denom_pub, - const struct GNUNET_HashCode *denom_pub_hash, - struct GNUNET_TIME_Absolute timestamp, - const struct TALER_MerchantPublicKeyP *merchant_pub, - struct GNUNET_TIME_Absolute refund_deadline, - const struct TALER_CoinSpendSignatureP *coin_sig) -{ - { - struct TALER_DepositRequestPS dr = { - .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_DEPOSIT), - .purpose.size = htonl (sizeof (dr)), - .h_contract_terms = *h_contract_terms, - .h_wire = *h_wire, - .timestamp = GNUNET_TIME_absolute_hton (timestamp), - .refund_deadline = GNUNET_TIME_absolute_hton (refund_deadline), - .merchant = *merchant_pub, - .coin_pub = *coin_pub - }; - - TALER_amount_hton (&dr.amount_with_fee, - amount); - TALER_amount_hton (&dr.deposit_fee, - &dki->fee_deposit); - if (GNUNET_OK != - GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_WALLET_COIN_DEPOSIT, - &dr.purpose, - &coin_sig->eddsa_signature, - &coin_pub->eddsa_pub)) - { - GNUNET_break_op (0); - TALER_LOG_WARNING ("Invalid coin signature on /deposit request!\n"); - { - TALER_LOG_DEBUG ("... amount_with_fee was %s\n", - TALER_amount2s (amount)); - TALER_LOG_DEBUG ("... deposit_fee was %s\n", - TALER_amount2s (&dki->fee_deposit)); - } - return GNUNET_SYSERR; - } - } - - /* check coin signature */ - { - struct TALER_CoinPublicInfo coin_info = { - .coin_pub = *coin_pub, - .denom_pub_hash = *denom_pub_hash, - .denom_sig = *denom_sig - }; - - if (GNUNET_YES != - TALER_test_coin_valid (&coin_info, - denom_pub)) - { - GNUNET_break_op (0); - TALER_LOG_WARNING ("Invalid coin passed for /deposit\n"); - return GNUNET_SYSERR; - } - } - - /* Check coin does make a contribution */ - if (0 < TALER_amount_cmp (&dki->fee_deposit, - amount)) - { - GNUNET_break_op (0); - TALER_LOG_WARNING ("Deposit amount smaller than fee\n"); - return GNUNET_SYSERR; - } - return GNUNET_OK; -} - - -/** - * Submit a deposit permission to the exchange and get the exchange's response. - * Note that while we return the response verbatim to the caller for - * further processing, we do already verify that the response is - * well-formed (i.e. that signatures included in the response are all - * valid). If the exchange's reply is not well-formed, we return an - * HTTP status code of zero to @a cb. - * - * We also verify that the @a coin_sig is valid for this deposit - * request, and that the @a ub_sig is a valid signature for @a - * coin_pub. Also, the @a exchange must be ready to operate (i.e. have - * finished processing the /keys reply). If either check fails, we do - * NOT initiate the transaction with the exchange and instead return NULL. - * - * @param exchange the exchange handle; the exchange must be ready to operate - * @param amount the amount to be deposited - * @param wire_deadline date until which the merchant would like the exchange to settle the balance (advisory, the exchange cannot be - * forced to settle in the past or upon very short notice, but of course a well-behaved exchange will limit aggregation based on the advice received) - * @param wire_details the merchant’s account details, in a format supported by the exchange - * @param h_contract_terms hash of the contact of the merchant with the customer (further details are never disclosed to the exchange) - * @param coin_pub coin’s public key - * @param denom_pub denomination key with which the coin is signed - * @param denom_sig exchange’s unblinded signature of the coin - * @param timestamp timestamp when the contract was finalized, must not be too far in the future - * @param merchant_pub the public key of the merchant (used to identify the merchant for refund requests) - * @param refund_deadline date until which the merchant can issue a refund to the customer via the exchange (can be zero if refunds are not allowed); must not be after the @a wire_deadline - * @param coin_sig the signature made with purpose #TALER_SIGNATURE_WALLET_COIN_DEPOSIT made by the customer with the coin’s private key. - * @param cb the callback to call when a reply for this request is available - * @param cb_cls closure for the above callback - * @return a handle for this request; NULL if the inputs are invalid (i.e. - * signatures fail to verify). In this case, the callback is not called. - */ -struct TALER_EXCHANGE_DepositHandle * -TALER_EXCHANGE_deposit (struct TALER_EXCHANGE_Handle *exchange, - const struct TALER_Amount *amount, - struct GNUNET_TIME_Absolute wire_deadline, - json_t *wire_details, - const struct GNUNET_HashCode *h_contract_terms, - const struct TALER_CoinSpendPublicKeyP *coin_pub, - const struct TALER_DenominationSignature *denom_sig, - const struct TALER_DenominationPublicKey *denom_pub, - struct GNUNET_TIME_Absolute timestamp, - const struct TALER_MerchantPublicKeyP *merchant_pub, - struct GNUNET_TIME_Absolute refund_deadline, - const struct TALER_CoinSpendSignatureP *coin_sig, - TALER_EXCHANGE_DepositResultCallback cb, - void *cb_cls) -{ - const struct TALER_EXCHANGE_Keys *key_state; - const struct TALER_EXCHANGE_DenomPublicKey *dki; - struct TALER_EXCHANGE_DepositHandle *dh; - struct GNUNET_CURL_Context *ctx; - json_t *deposit_obj; - CURL *eh; - struct GNUNET_HashCode h_wire; - struct GNUNET_HashCode denom_pub_hash; - struct TALER_Amount amount_without_fee; - char arg_str[sizeof (struct TALER_CoinSpendPublicKeyP) * 2 + 32]; - - { - char pub_str[sizeof (struct TALER_CoinSpendPublicKeyP) * 2]; - char *end; - - end = GNUNET_STRINGS_data_to_string (coin_pub, - sizeof (struct - TALER_CoinSpendPublicKeyP), - pub_str, - sizeof (pub_str)); - *end = '\0'; - GNUNET_snprintf (arg_str, - sizeof (arg_str), - "/coins/%s/deposit", - pub_str); - } - (void) GNUNET_TIME_round_abs (&wire_deadline); - (void) GNUNET_TIME_round_abs (&refund_deadline); - if (refund_deadline.abs_value_us > wire_deadline.abs_value_us) - { - GNUNET_break (0); - return NULL; - } - GNUNET_assert (GNUNET_YES == - TEAH_handle_is_ready (exchange)); - /* initialize h_wire */ - if (GNUNET_OK != - TALER_JSON_merchant_wire_signature_hash (wire_details, - &h_wire)) - { - GNUNET_break (0); - return NULL; - } - key_state = TALER_EXCHANGE_get_keys (exchange); - dki = TALER_EXCHANGE_get_denomination_key (key_state, - denom_pub); - if (NULL == dki) - { - GNUNET_break (0); - return NULL; - } - if (GNUNET_SYSERR == - TALER_amount_subtract (&amount_without_fee, - amount, - &dki->fee_deposit)) - { - GNUNET_break_op (0); - return NULL; - } - GNUNET_CRYPTO_rsa_public_key_hash (denom_pub->rsa_public_key, - &denom_pub_hash); - if (GNUNET_OK != - verify_signatures (dki, - amount, - &h_wire, - h_contract_terms, - coin_pub, - denom_sig, - denom_pub, - &denom_pub_hash, - timestamp, - merchant_pub, - refund_deadline, - coin_sig)) - { - GNUNET_break_op (0); - return NULL; - } - - deposit_obj = json_pack ("{s:o, s:O," /* f/wire */ - " s:o, s:o," /* h_wire, h_contract_terms */ - " s:o," /* denom_pub */ - " s:o, s:o," /* ub_sig, timestamp */ - " s:o," /* merchant_pub */ - " s:o, s:o," /* refund_deadline, wire_deadline */ - " s:o}", /* coin_sig */ - "contribution", TALER_JSON_from_amount (amount), - "wire", wire_details, - "h_wire", GNUNET_JSON_from_data_auto (&h_wire), - "h_contract_terms", GNUNET_JSON_from_data_auto ( - h_contract_terms), - "denom_pub_hash", GNUNET_JSON_from_data_auto ( - &denom_pub_hash), - "ub_sig", GNUNET_JSON_from_rsa_signature ( - denom_sig->rsa_signature), - "timestamp", GNUNET_JSON_from_time_abs (timestamp), - "merchant_pub", GNUNET_JSON_from_data_auto ( - merchant_pub), - "refund_deadline", GNUNET_JSON_from_time_abs ( - refund_deadline), - "wire_transfer_deadline", GNUNET_JSON_from_time_abs ( - wire_deadline), - "coin_sig", GNUNET_JSON_from_data_auto (coin_sig) - ); - if (NULL == deposit_obj) - { - GNUNET_break (0); - return NULL; - } - - dh = GNUNET_new (struct TALER_EXCHANGE_DepositHandle); - dh->auditor_chance = AUDITOR_CHANCE; - dh->exchange = exchange; - dh->cb = cb; - dh->cb_cls = cb_cls; - dh->url = TEAH_path_to_url (exchange, - arg_str); - dh->depconf.purpose.size = htonl (sizeof (struct - TALER_DepositConfirmationPS)); - dh->depconf.purpose.purpose = htonl ( - TALER_SIGNATURE_EXCHANGE_CONFIRM_DEPOSIT); - dh->depconf.h_contract_terms = *h_contract_terms; - dh->depconf.h_wire = h_wire; - dh->depconf.timestamp = GNUNET_TIME_absolute_hton (timestamp); - dh->depconf.refund_deadline = GNUNET_TIME_absolute_hton (refund_deadline); - TALER_amount_hton (&dh->depconf.amount_without_fee, - &amount_without_fee); - dh->depconf.coin_pub = *coin_pub; - dh->depconf.merchant = *merchant_pub; - dh->amount_with_fee = *amount; - dh->dki = *dki; - dh->dki.key.rsa_public_key = NULL; /* lifetime not warranted, so better - not copy the pointer */ - - eh = TALER_EXCHANGE_curl_easy_get_ (dh->url); - if ( (NULL == eh) || - (GNUNET_OK != - TALER_curl_easy_post (&dh->ctx, - eh, - deposit_obj)) ) - { - GNUNET_break (0); - if (NULL != eh) - curl_easy_cleanup (eh); - json_decref (deposit_obj); - GNUNET_free (dh->url); - GNUNET_free (dh); - return NULL; - } - json_decref (deposit_obj); - GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, - "URL for deposit: `%s'\n", - dh->url); - ctx = TEAH_handle_to_context (exchange); - dh->job = GNUNET_CURL_job_add2 (ctx, - eh, - dh->ctx.headers, - &handle_deposit_finished, - dh); - return dh; -} - - -/** - * Change the chance that our deposit confirmation will be given to the - * auditor to 100%. - * - * @param deposit the deposit permission request handle - */ -void -TALER_EXCHANGE_deposit_force_dc (struct TALER_EXCHANGE_DepositHandle *deposit) -{ - deposit->auditor_chance = 1; -} - - -/** - * Cancel a deposit permission request. This function cannot be used - * on a request handle if a response is already served for it. - * - * @param deposit the deposit permission request handle - */ -void -TALER_EXCHANGE_deposit_cancel (struct TALER_EXCHANGE_DepositHandle *deposit) -{ - if (NULL != deposit->job) - { - GNUNET_CURL_job_cancel (deposit->job); - deposit->job = NULL; - } - GNUNET_free (deposit->url); - TALER_curl_easy_post_finished (&deposit->ctx); - GNUNET_free (deposit); -} - - -/* end of exchange_api_deposit.c */ |