WiP: age-withdraw implementation, part 2/n

Commit phase of the age-withdraw protocol implemented, according to
https://docs.taler.net/core/api-exchange.html#withdraw-with-age-restriction

- added new files, forgot in previous commit
This commit is contained in:
Özgür Kesim 2023-03-01 11:14:30 +01:00
parent b4128c2c2a
commit 468006c60b
Signed by: oec
GPG Key ID: 3D76A56D79EDD9D7
6 changed files with 928 additions and 0 deletions

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/*
This file is part of TALER
Copyright (C) 2023 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_age-withdraw.c
* @brief Handle /reserves/$RESERVE_PUB/age-withdraw requests
* @author Özgür Kesim
*/
#include "platform.h"
#include <gnunet/gnunet_util_lib.h>
#include <jansson.h>
#include "taler_json_lib.h"
#include "taler_kyclogic_lib.h"
#include "taler_mhd_lib.h"
#include "taler-exchange-httpd_age-withdraw.h"
#include "taler-exchange-httpd_responses.h"
#include "taler-exchange-httpd_keys.h"
/**
* Send a response to a "age-withdraw" request.
*
* @param connection the connection to send the response to
* @param ach value the client committed to
* @param noreveal_index which index will the client not have to reveal
* @return a MHD status code
*/
static MHD_RESULT
reply_age_withdraw_success (
struct MHD_Connection *connection,
const struct TALER_AgeWithdrawCommitmentHashP *ach,
uint32_t noreveal_index)
{
struct TALER_ExchangePublicKeyP pub;
struct TALER_ExchangeSignatureP sig;
enum TALER_ErrorCode ec =
TALER_exchange_online_age_withdraw_confirmation_sign (
&TEH_keys_exchange_sign_,
ach,
noreveal_index,
&pub,
&sig);
if (TALER_EC_NONE != ec)
return TALER_MHD_reply_with_ec (connection,
ec,
NULL);
return TALER_MHD_REPLY_JSON_PACK (connection,
MHD_HTTP_OK,
GNUNET_JSON_pack_uint64 ("noreveal_index",
noreveal_index),
GNUNET_JSON_pack_data_auto ("exchange_sig",
&sig),
GNUNET_JSON_pack_data_auto ("exchange_pub",
&pub));
}
/**
* Context for #age_withdraw_transaction.
*/
struct AgeWithdrawContext
{
/**
* KYC status for the operation.
*/
struct TALER_EXCHANGEDB_KycStatus kyc;
/**
* Hash of the wire source URL, needed when kyc is needed.
*/
struct TALER_PaytoHashP h_payto;
/**
* The data from the age-withdraw request
*/
struct TALER_EXCHANGEDB_AgeWithdrawCommitment commitment;
/**
* Current time for the DB transaction.
*/
struct GNUNET_TIME_Timestamp now;
};
/**
* Function called to iterate over KYC-relevant
* transaction amounts for a particular time range.
* Called within a database transaction, so must
* not start a new one.
*
* @param cls closure, identifies the event type and
* account to iterate over events for
* @param limit maximum time-range for which events
* should be fetched (timestamp in the past)
* @param cb function to call on each event found,
* events must be returned in reverse chronological
* order
* @param cb_cls closure for @a cb
*/
static void
age_withdraw_amount_cb (void *cls,
struct GNUNET_TIME_Absolute limit,
TALER_EXCHANGEDB_KycAmountCallback cb,
void *cb_cls)
{
struct AgeWithdrawContext *awc = cls;
enum GNUNET_DB_QueryStatus qs;
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Signaling amount %s for KYC check during age-withdrawal\n",
TALER_amount2s (&awc->commitment.amount_with_fee));
if (GNUNET_OK !=
cb (cb_cls,
&awc->commitment.amount_with_fee,
awc->now.abs_time))
return;
qs = TEH_plugin->select_withdraw_amounts_for_kyc_check (TEH_plugin->cls,
&awc->h_payto,
limit,
cb,
cb_cls);
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Got %d additional transactions for this age-withdrawal and limit %llu\n",
qs,
(unsigned long long) limit.abs_value_us);
GNUNET_break (qs >= 0);
}
/**
* Function implementing age 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 "awc->commitment.sig" is set before entering this function as we
* signed before entering the transaction.
*
* @param cls a `struct AgeWithdrawContext *`
* @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
age_withdraw_transaction (void *cls,
struct MHD_Connection *connection,
MHD_RESULT *mhd_ret)
{
struct AgeWithdrawContext *awc = cls;
enum GNUNET_DB_QueryStatus qs;
bool found = false;
bool balance_ok = false;
uint64_t ruuid;
awc->now = GNUNET_TIME_timestamp_get ();
qs = TEH_plugin->reserves_get_origin (TEH_plugin->cls,
&awc->commitment.reserve_pub,
&awc->h_payto);
if (qs < 0)
return qs;
/* If no results, reserve was created by merge,
in which case no KYC check is required as the
merge already did that. */
if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT == qs)
{
char *kyc_required;
qs = TALER_KYCLOGIC_kyc_test_required (
TALER_KYCLOGIC_KYC_TRIGGER_AGE_WITHDRAW,
&awc->h_payto,
TEH_plugin->select_satisfied_kyc_processes,
TEH_plugin->cls,
&age_withdraw_amount_cb,
awc,
&kyc_required);
if (qs < 0)
{
if (GNUNET_DB_STATUS_HARD_ERROR == qs)
{
GNUNET_break (0);
*mhd_ret = TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_GENERIC_DB_FETCH_FAILED,
"kyc_test_required");
}
return qs;
}
if (NULL != kyc_required)
{
/* insert KYC requirement into DB! */
awc->kyc.ok = false;
return TEH_plugin->insert_kyc_requirement_for_account (
TEH_plugin->cls,
kyc_required,
&awc->h_payto,
&awc->kyc.requirement_row);
}
}
awc->kyc.ok = true;
qs = TEH_plugin->do_age_withdraw (TEH_plugin->cls,
&awc->commitment,
awc->now,
&found,
&balance_ok,
&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,
"do_age_withdraw");
return qs;
}
else 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;
}
else if (! balance_ok)
{
TEH_plugin->rollback (TEH_plugin->cls);
*mhd_ret = TEH_RESPONSE_reply_reserve_insufficient_balance (
connection,
TALER_EC_EXCHANGE_AGE_WITHDRAW_INSUFFICIENT_FUNDS,
&awc->commitment.amount_with_fee,
&awc->commitment.reserve_pub);
return GNUNET_DB_STATUS_HARD_ERROR;
}
if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT == qs)
TEH_METRICS_num_success[TEH_MT_SUCCESS_AGE_WITHDRAW]++;
return qs;
}
/**
* 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[in,out] awc 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
request_is_idempotent (struct TEH_RequestContext *rc,
struct AgeWithdrawContext *awc,
MHD_RESULT *mret)
{
enum GNUNET_DB_QueryStatus qs;
struct TALER_EXCHANGEDB_AgeWithdrawCommitment commitment;
qs = TEH_plugin->get_age_withdraw_info (TEH_plugin->cls,
&awc->commitment.reserve_pub,
&awc->commitment.h_commitment,
&commitment);
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_age_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_AGE_WITHDRAW]++;
*mret = reply_age_withdraw_success (rc->connection,
&commitment.h_commitment,
commitment.noreveal_index);
return true;
}
MHD_RESULT
TEH_handler_age_withdraw (struct TEH_RequestContext *rc,
const struct TALER_ReservePublicKeyP *reserve_pub,
const json_t *root)
{
MHD_RESULT mhd_ret;
struct AgeWithdrawContext awc;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("reserve_sig",
&awc.commitment.reserve_sig),
GNUNET_JSON_spec_fixed_auto ("h_commitment",
&awc.commitment.h_commitment),
TALER_JSON_spec_amount ("amount",
TEH_currency,
&awc.commitment.amount_with_fee),
GNUNET_JSON_spec_uint32 ("max_age_group",
&awc.commitment.max_age_group),
GNUNET_JSON_spec_end ()
};
memset (&awc, 0, sizeof (awc));
awc.commitment.reserve_pub = *reserve_pub;
/* Parse the JSON body */
{
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;
}
do {
/* If request was made before successfully, return the previous answer */
if (request_is_idempotent (rc,
&awc,
&mhd_ret))
break;
/* Verify the signature of the request body with the reserve key */
TEH_METRICS_num_verifications[TEH_MT_SIGNATURE_EDDSA]++;
if (GNUNET_OK !=
TALER_wallet_age_withdraw_verify (&awc.commitment.h_commitment,
&awc.commitment.amount_with_fee,
awc.commitment.max_age_group,
&awc.commitment.reserve_pub,
&awc.commitment.reserve_sig))
{
GNUNET_break_op (0);
mhd_ret = TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_FORBIDDEN,
TALER_EC_EXCHANGE_WITHDRAW_RESERVE_SIGNATURE_INVALID,
NULL);
break;
}
/* Run the transaction */
if (GNUNET_OK !=
TEH_DB_run_transaction (rc->connection,
"run age withdraw",
TEH_MT_REQUEST_AGE_WITHDRAW,
&mhd_ret,
&age_withdraw_transaction,
&awc))
break;
/* Clean up and send back final response */
GNUNET_JSON_parse_free (spec);
if (! awc.kyc.ok)
return TEH_RESPONSE_reply_kyc_required (rc->connection,
&awc.h_payto,
&awc.kyc);
return reply_age_withdraw_success (rc->connection,
&awc.commitment.h_commitment,
awc.commitment.noreveal_index);
} while(0);
GNUNET_JSON_parse_free (spec);
return mhd_ret;
}
/* end of taler-exchange-httpd_age-withdraw.c */

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/*
This file is part of TALER
Copyright (C) 2023 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_age-withdraw.h
* @brief Handle /reserve/$RESERVE_PUB/age-withdraw requests
* @author Özgür Kesim
*/
#ifndef TALER_EXCHANGE_HTTPD_AGE_WITHDRAW_H
#define TALER_EXCHANGE_HTTPD_AGE_WITHDRAW_H
#include <microhttpd.h>
#include "taler-exchange-httpd.h"
/**
* Handle a "/reserves/$RESERVE_PUB/age-withdraw" request.
*
* Parses the batch of commitments to withdraw age restricted coins, and checks
* that the signature "reserve_sig" makes this a valid withdrawal request from
* the specified reserve. If the request is valid, the response contains a
* noreveal_index which the client has to use for the subsequent call to
* /age-withdraw/$ACH/reveal.
*
* @param rc request context
* @param root uploaded JSON data
* @param reserve_pub public key of the reserve
* @return MHD result code
*/
MHD_RESULT
TEH_handler_age_withdraw (struct TEH_RequestContext *rc,
const struct TALER_ReservePublicKeyP *reserve_pub,
const json_t *root);
#endif

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/*
This file is part of TALER
Copyright (C) 2023 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_age-withdraw_reveal.c
* @brief Handle /age-withdraw/$ACH/reveal requests
* @author Özgür Kesim
*/
#include "platform.h"
#include <gnunet/gnunet_util_lib.h>
#include <jansson.h>
#include <microhttpd.h>
#include "taler_mhd_lib.h"
#include "taler-exchange-httpd_mhd.h"
#include "taler-exchange-httpd_age-withdraw_reveal.h"
#include "taler-exchange-httpd_responses.h"
#include "taler-exchange-httpd_keys.h"
/**
* State for an /age-withdraw/$ACH/reveal operation.
*/
struct AgeRevealContext
{
/**
* Commitment for the age-withdraw operation.
*/
struct TALER_AgeWithdrawCommitmentHashP ach;
/**
* Public key of the reserve for with the age-withdraw commitment was
* originally made. This parameter is provided by the client again
* during the call to reveal in order to save a database-lookup .
*/
struct TALER_ReservePublicKeyP reserve_pub;
/**
* Number of coins/denonations in the reveal
*/
uint32_t num_coins;
/**
* TODO:oec num_coins denoms
*/
struct TALER_DenominationHashP *denoms_h;
/**
* TODO:oec num_coins blinded coins
*/
struct TALER_BlindedCoinHashP *coin_evs;
/**
* TODO:oec num_coins*(kappa - 1) disclosed coins
*/
struct GNUNET_CRYPTO_EddsaPrivateKey *disclosed_coins;
};
/**
* Helper function to free resources in the context
*/
void
age_reveal_context_free (struct AgeRevealContext *actx)
{
GNUNET_free (actx->denoms_h);
GNUNET_free (actx->coin_evs);
GNUNET_free (actx->disclosed_coins);
}
/**
* Handle a "/age-withdraw/$ACH/reveal request. Parses the given JSON
* ... TODO:oec:description
*
* @param connection The MHD connection to handle
* @param actx The context of the operation, only partially built at call time
* @param j_denoms_h Array of hashes of the denominations for the withdrawal, in JSON format
* @param j_coin_evs The blinded envelopes in JSON format for the coins that are not revealed and will be signed on success
* @param j_disclosed_coins The n*(kappa-1) disclosed coins' private keys in JSON format, from which all other attributes (age restriction, blinding, nonce) will be derived from
*/
MHD_RESULT
handle_age_withdraw_reveal_json (
struct MHD_Connection *connection,
struct AgeRevealContext *actx,
const json_t *j_denoms_h,
const json_t *j_coin_evs,
const json_t *j_disclosed_coins)
{
MHD_RESULT mhd_ret = MHD_NO;
/* Verify JSON-structure consistency */
{
const char *error = NULL;
actx->num_coins = json_array_size (j_denoms_h); /* 0, if j_denoms_h is not an array */
if (! json_is_array (j_denoms_h))
error = "denoms_h must be an array";
else if (! json_is_array (j_coin_evs))
error = "coin_evs must be an array";
else if (! json_is_array (j_disclosed_coins))
error = "disclosed_coins must be an array";
else if (actx->num_coins == 0)
error = "denoms_h must not be empty";
else if (actx->num_coins != json_array_size (j_coin_evs))
error = "denoms_h and coins_evs must be arrays of the same size";
else if (actx->num_coins * (TALER_CNC_KAPPA - 1)
!= json_array_size (j_disclosed_coins))
error = "the size of array disclosed_coins must be "
TALER_CNC_KAPPA_MINUS_ONE_STR " times of the size of denoms_h";
else if (actx->num_coins > TALER_MAX_FRESH_COINS)
/**
* FIXME?: If the user had commited to more than the maximum coins allowed,
* the reserve has been charged, but now the user can not withdraw any money
* from it. How can the user get their money back?
**/
error = "maximum number of coins that can be withdrawn has been exceeded";
if (NULL != error)
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_BAD_REQUEST,
TALER_EC_GENERIC_PARAMETER_MALFORMED,
error);
}
/* Parse denomination keys */
{
unsigned int idx;
json_t *jh;
actx->denoms_h = GNUNET_new_array (actx->num_coins,
struct TALER_DenominationHashP);
json_array_foreach (j_denoms_h, idx, jh) {
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto (NULL, &actx->denoms_h[idx]),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (jh, spec, NULL, NULL))
{
char msg[256] = {0};
GNUNET_snprintf (msg,
sizeof(msg),
"couldn't parse entry no. %d in array denoms_h",
idx + 1);
mhd_ret = TALER_MHD_reply_with_error (connection,
MHD_HTTP_BAD_REQUEST,
TALER_EC_GENERIC_PARAMETER_MALFORMED,
msg);
goto EXIT;
}
};
}
/* Parse blinded envelopes */
{
unsigned int idx;
json_t *ce;
actx->coin_evs = GNUNET_new_array (actx->num_coins,
struct TALER_BlindedCoinHashP);
json_array_foreach (j_coin_evs, idx, ce) {
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto (NULL, &actx->coin_evs[idx]),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (ce, spec, NULL, NULL))
{
char msg[256] = {0};
GNUNET_snprintf (msg,
sizeof(msg),
"couldn't parse entry no. %d in array coin_evs",
idx + 1);
mhd_ret = TALER_MHD_reply_with_error (connection,
MHD_HTTP_BAD_REQUEST,
TALER_EC_GENERIC_PARAMETER_MALFORMED,
msg);
goto EXIT;
}
};
}
/* Parse diclosed keys */
{
unsigned int idx;
json_t *dc;
actx->disclosed_coins = GNUNET_new_array (
actx->num_coins * (TALER_CNC_KAPPA),
struct GNUNET_CRYPTO_EddsaPrivateKey);
json_array_foreach (j_coin_evs, idx, dc) {
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto (NULL, &actx->disclosed_coins[idx]),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (dc, spec, NULL, NULL))
{
char msg[256] = {0};
GNUNET_snprintf (msg,
sizeof(msg),
"couldn't parse entry no. %d in array disclosed_coins",
idx + 1);
mhd_ret = TALER_MHD_reply_with_error (connection,
MHD_HTTP_BAD_REQUEST,
TALER_EC_GENERIC_PARAMETER_MALFORMED,
msg);
goto EXIT;
}
};
}
/* TODO:oec: find commitment */
/* TODO:oec: check validity of denoms */
/* TODO:oec: check amount total against denoms */
/* TODO:oec: compute the disclosed blinded coins */
/* TODO:oec: generate h_commitment_comp */
/* TODO:oec: compare h_commitment_comp against h_commitment */
/* TODO:oec: sign the coins */
/* TODO:oec: send response */
/* TODO */
EXIT:
age_reveal_context_free (actx);
return mhd_ret;
}
MHD_RESULT
TEH_handler_age_withdraw_reveal (
struct TEH_RequestContext *rc,
const struct TALER_AgeWithdrawCommitmentHashP *ach,
const json_t *root)
{
struct AgeRevealContext actx = {0};
json_t *j_denoms_h;
json_t *j_coin_evs;
json_t *j_disclosed_coins;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("reserve_pub", &actx.reserve_pub),
GNUNET_JSON_spec_json ("denoms_h", &j_denoms_h),
GNUNET_JSON_spec_json ("coin_evs", &j_coin_evs),
GNUNET_JSON_spec_json ("disclosed_coins", &j_disclosed_coins),
GNUNET_JSON_spec_end ()
};
actx.ach = *ach;
/* Parse JSON body*/
{
enum GNUNET_GenericReturnValue res;
res = TALER_MHD_parse_json_data (rc->connection,
root,
spec);
if (GNUNET_OK != res)
{
GNUNET_break_op (0);
return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
}
}
/* handle reveal request */
{
MHD_RESULT res;
res = handle_age_withdraw_reveal_json (rc->connection,
&actx,
j_denoms_h,
j_coin_evs,
j_disclosed_coins);
GNUNET_JSON_parse_free (spec);
return res;
}
}
/* end of taler-exchange-httpd_age-withdraw_reveal.c */

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/*
This file is part of TALER
Copyright (C) 2023 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_age-withdraw_reveal.h
* @brief Handle /age-withdraw/$ACH/reveal requests
* @author Özgür Kesim
*/
#ifndef TALER_EXCHANGE_HTTPD_AGE_WITHDRAW_H
#define TALER_EXCHANGE_HTTPD_AGE_WITHDRAW_H
#include <microhttpd.h>
#include "taler-exchange-httpd.h"
/**
* Handle a "/age-withdraw/$ACH/reveal" request.
*
* The client got a noreveal_index in response to a previous request
* /reserve/$RESERVE_PUB/age-withdraw. It now has to reveal all n*(kappa-1)
* coin's private keys (except for the noreveal_index), from which all other
* coin-relevant data (blinding, age restriction, nonce) is derived from.
*
* The exchange computes those values, ensures that the maximum age is
* correctly applied, calculates the hash of the blinded envelopes, and -
* together with the non-disclosed blinded envelopes - compares the hash of
* those against the original commitment $ACH.
*
* If all those checks and the used denominations turn out to be correct, the
* exchange signs all blinded envelopes with their appropriate denomination
* keys.
*
* @param rc request context
* @param root uploaded JSON data
* @param ach commitment to the age restricted coints from the age-withdraw request
* @return MHD result code
*/
MHD_RESULT
TEH_handler_age_withdraw_reveal (
struct TEH_RequestContext *rc,
const struct TALER_AgeWithdrawCommitmentHashP *ach,
const json_t *root);
#endif

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/*
This file is part of TALER
Copyright (C) 2023 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 exchangedb/pg_get_age_withdraw_info.c
* @brief Implementation of the get_age_withdraw_info function for Postgres
* @author Özgür Kesim
*/
#include "platform.h"
#include "taler_error_codes.h"
#include "taler_dbevents.h"
#include "taler_pq_lib.h"
#include "pg_get_age_withdraw_info.h"
#include "pg_helper.h"
enum GNUNET_DB_QueryStatus
TEH_PG_get_age_withdraw_info (
void *cls,
const struct TALER_ReservePublicKeyP *reserve_pub,
const struct TALER_AgeWithdrawCommitmentHashP *ach,
struct TALER_EXCHANGEDB_AgeWithdrawCommitment *awc)
{
struct PostgresClosure *pg = cls;
struct GNUNET_PQ_QueryParam params[] = {
GNUNET_PQ_query_param_auto_from_type (ach),
GNUNET_PQ_query_param_end
};
struct GNUNET_PQ_ResultSpec rs[] = {
GNUNET_PQ_result_spec_auto_from_type ("h_commitment",
&awc->h_commitment),
GNUNET_PQ_result_spec_auto_from_type ("reserve_sig",
&awc->reserve_sig),
GNUNET_PQ_result_spec_auto_from_type ("reserve_pub",
&awc->reserve_pub),
GNUNET_PQ_result_spec_uint32 ("max_age_group",
&awc->max_age_group),
TALER_PQ_RESULT_SPEC_AMOUNT ("amount_with_fee",
&awc->amount_with_fee),
GNUNET_PQ_result_spec_uint32 ("noreveal_index",
&awc->noreveal_index),
GNUNET_PQ_result_spec_timestamp ("timtestamp",
&awc->timestamp),
GNUNET_PQ_result_spec_end
};
/* Used in #postgres_get_age_withdraw_info() to
locate the response for a /reserve/$RESERVE_PUB/age-withdraw request using
the hash of the blinded message. Used to make sure
/reserve/$RESERVE_PUB/age-withdraw requests are idempotent. */
PREPARE (pg,
"get_age_withdraw_info",
"SELECT"
" h_commitment"
",reserve_sig"
",reserve_pub"
",max_age_group"
",amount_with_fee_val"
",amount_with_fee_frac"
",noreveal_index"
",timestamp"
" FROM withdraw_age_commitments"
" WHERE h_commitment=$1;");
return GNUNET_PQ_eval_prepared_singleton_select (pg->conn,
"get_age_withdraw_info",
params,
rs);
}

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/*
This file is part of TALER
Copyright (C) 2023 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 exchangedb/pg_get_age_withdraw_info.h
* @brief implementation of the get_age_withdraw_info function for Postgres
* @author Özgür KESIM
*/
#ifndef PG_GET_AGE_WITHDRAW_INFO_H
#define PG_GET_AGE_WITHDRAW_INFO_H
#include "taler_util.h"
#include "taler_json_lib.h"
#include "taler_exchangedb_plugin.h"
/**
* Locate the response for a age-withdraw request under a hash that uniquely
* identifies the age-withdraw operation. Used to ensure idempotency of the
* request.
*
* @param cls the @e cls of this struct with the plugin-specific state
* @param reserve_pub public key of the reserve for which the age-withdraw request is made
* @param ach hash that uniquely identifies the age-withdraw operation
* @param[out] awc corresponding details of the previous age-withdraw request if an entry was found
* @return statement execution status
*/
enum GNUNET_DB_QueryStatus
TEH_PG_get_age_withdraw_info (
void *cls,
const struct TALER_ReservePublicKeyP *reserve_pub,
const struct TALER_AgeWithdrawCommitmentHashP *ach,
struct TALER_EXCHANGEDB_AgeWithdrawCommitment *awc);
#endif