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WIP: first steps towards age-withdraw, DOESN'T COMPILE YET

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Özgür Kesim 2023-01-21 10:11:10 +01:00
parent 10cf3b3b65
commit eee50cef06
Signed by: oec
GPG Key ID: 3D76A56D79EDD9D7
6 changed files with 538 additions and 0 deletions
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2
src/exchange/Makefile.am
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@ -122,6 +122,8 @@ taler_exchange_wirewatch_LDADD = \
taler_exchange_httpd_SOURCES = \
taler-exchange-httpd.c taler-exchange-httpd.h \
taler-exchange-httpd_age-withdraw.c taler-exchange-httpd_age-withdraw.h \
taler-exchange-httpd_age-withdraw_reveal.c taler-exchange-httpd_age-withdraw_reveal.h \
taler-exchange-httpd_auditors.c taler-exchange-httpd_auditors.h \
taler-exchange-httpd_aml-decision.c taler-exchange-httpd_aml-decision.h \
taler-exchange-httpd_batch-deposit.c taler-exchange-httpd_batch-deposit.h \

385
src/exchange/taler-exchange-httpd_age-withdraw.c Normal file
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@ -0,0 +1,385 @@
/*
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_withdraw.h"
#include "taler-exchange-httpd_responses.h"
#include "taler-exchange-httpd_keys.h"
/**
* Context for #age_withdraw_transaction.
*/
struct AgeWithdrawContext
{
/**
* KYC status for the operation.
*/
struct TALER_EXCHANGEDB_KycStatus kyc;
/**
* The commitment request, for n*kappa coins.
*/
struct TALER_EXCHANGEDB_AgeWithdrawCommitment commitment;
/**
* Current time for the DB transaction.
*/
struct GNUNET_TIME_Timestamp now;
};
#if 0
/**
* 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
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->amount_with_fee));
if (GNUNET_OK !=
cb (cb_cls,
&awc->amount_with_fee,
awc->now.abs_time))
return;
qs = TEH_plugin->select_withdraw_amounts_for_kyc_check (
TEH_plugin->cls,
&wc->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);
}
#endif
#if 0
/**
* TODO: REWRITE
* 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 "wc->collectable.sig" is set before entering this function as we
* signed before entering the transaction.
*
* @param cls a `struct WithdrawContext *`
* @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 *wc = cls;
enum GNUNET_DB_QueryStatus qs;
bool found = false;
bool balance_ok = false;
bool nonce_ok = false;
uint64_t ruuid;
const struct TALER_CsNonce *nonce;
const struct TALER_BlindedPlanchet *bp;
wc->now = GNUNET_TIME_timestamp_get ();
qs = TEH_plugin->reserves_get_origin (TEH_plugin->cls,
&wc->collectable.reserve_pub,
&wc->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)
{
const char *kyc_required;
kyc_required = TALER_KYCLOGIC_kyc_test_required (
TALER_KYCLOGIC_KYC_TRIGGER_WITHDRAW,
&wc->h_payto,
TEH_plugin->select_satisfied_kyc_processes,
TEH_plugin->cls,
&withdraw_amount_cb,
wc);
if (NULL != kyc_required)
{
/* insert KYC requirement into DB! */
wc->kyc.ok = false;
return TEH_plugin->insert_kyc_requirement_for_account (
TEH_plugin->cls,
kyc_required,
&wc->h_payto,
&wc->kyc.requirement_row);
}
}
wc->kyc.ok = true;
bp = &wc->blinded_planchet;
nonce = (TALER_DENOMINATION_CS == bp->cipher)
? &bp->details.cs_blinded_planchet.nonce
: NULL;
qs = TEH_plugin->do_withdraw (TEH_plugin->cls,
nonce,
&wc->collectable,
wc->now,
&found,
&balance_ok,
&nonce_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_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,
TALER_EC_EXCHANGE_WITHDRAW_INSUFFICIENT_FUNDS,
&wc->collectable.amount_with_fee,
&wc->collectable.reserve_pub);
return GNUNET_DB_STATUS_HARD_ERROR;
}
if (! nonce_ok)
{
TEH_plugin->rollback (TEH_plugin->cls);
*mhd_ret = TALER_MHD_reply_with_error (connection,
MHD_HTTP_CONFLICT,
TALER_EC_EXCHANGE_WITHDRAW_NONCE_REUSE,
NULL);
return GNUNET_DB_STATUS_HARD_ERROR;
}
if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT == qs)
TEH_METRICS_num_success[TEH_MT_SUCCESS_WITHDRAW]++;
return qs;
}
#endif
/**
* 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;
qs = TEH_plugin->get_age_withdraw_info (TEH_plugin->cls,
&awc->reserve_pub,
&awc->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 = TALER_MHD_REPLY_JSON_PACK (
rc->connection,
MHD_HTTP_OK,
GNUNET_JSON_pack_uint64 ("noreveal_index",
&awc->commitment.noreveal_index),
GNUNET_JSON_pack_data_auto ("exchange_sig",
&awc->commitment.sig),
GNUNET_JSON_pack_data_auto ("exchange_pub",
/* TODO:oec: where does the pub come from? */
&pub));
return true;
}
MHD_RESULT
TEH_handler_age_withdraw (struct TEH_RequestContext *rc,
const struct TALER_ReservePublicKeyP *reserve_pub,
const json_t *root)
{
struct AgeWithdrawContext awc;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("reserve_sig",
&awc.commitment.reserve_sig),
GNUNET_JSON_spec_fixed_auto ("age_restricted_coins_commitment",
&awc.commitment.h_commitment),
TALER_JSON_spec_amount ("amount",
&awc.commitment.amount_with_fee);
GNUNET_JSON_spec_uint8 ("max_age_group",
&awc.commitment.max_age_group),
GNUNET_JSON_spec_end ()
};
enum TALER_ErrorCode ec;
memset (&awc, 0, sizeof (awc));
awc.commitment.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 (request_is_idempotent (rc,
&awc,
&mret))
{
GNUNET_JSON_parse_free (spec);
return mret;
}
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);
GNUNET_JSON_parse_free (spec);
return TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_FORBIDDEN,
TALER_EC_EXCHANGE_WITHDRAW_RESERVE_SIGNATURE_INVALID,
NULL);
}
/* run transaction */
{
MHD_RESULT mhd_ret;
if (GNUNET_OK !=
TEH_DB_run_transaction (rc->connection,
"run age withdraw",
TEH_MT_REQUEST_AGE_WITHDRAW,
&mhd_ret,
&age_withdraw_transaction,
&awc))
{
/* Even if #withdraw_transaction() failed, it may have created a signature
(or we might have done it optimistically above). */
/*TODO:oec:which function to call here!? */
TALER_blinded_denom_sig_free (&awc.commitment.sig);
GNUNET_JSON_parse_free (spec);
return mhd_ret;
}
}
/* 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);
{
MHD_RESULT ret;
ret = TALER_MHD_REPLY_JSON_PACK (
rc->connection,
MHD_HTTP_OK,
/* TODO:oec: put in the right answer fields */
GNUNET_JSON_pack_uint64 ("noreveal_index",
&awc->commitment.noreveal_index),
GNUNET_JSON_pack_data_auto ("exchange_sig",
&awc->commitment.sig),
GNUNET_JSON_pack_data_auto ("exchange_pub",
/* TODO:oec: where does the pub come from? */
&pub));
TALER_blinded_denom_sig_free (&awc.commitment.sig);
return ret;
}
}
/* end of taler-exchange-httpd_age-withdraw.c */

47
src/exchange/taler-exchange-httpd_age-withdraw.h Normal file
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@ -0,0 +1,47 @@
/*
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

56
src/exchange/taler-exchange-httpd_age-withdraw_reveal.h Normal file
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@ -0,0 +1,56 @@
/*
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_AgeRestrictedCoinsCommitmentP *ach,
const json_t *root);
#endif

46
src/include/taler_exchangedb_plugin.h
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@ -1050,6 +1050,52 @@ struct TALER_EXCHANGEDB_CollectableBlindcoin
struct TALER_ReserveSignatureP reserve_sig;
};
/**
* @brief Information we keep for an age-withdraw commitment
* to reproduce the /age-withdraw operation if neede, and to have proof
* that a reserve was drained by this amount.
*/
struct TALER_EXCHANGEDB_AgeWithdrawCommitment
{
/**
* Total amount (with fee) committed to withdraw
*/
struct TALER_Amount amount_with_fee;
/**
* Public key of the reserve that was drained.
*/
struct TALER_ReservePublicKeyP reserve_pub;
/**
* Maximum age group that the coins are restricted to.
*/
uint8_t max_age_group;
/**
* The hash of the commitment of all n*kappa coins
*/
struct TALER_AgeWithdrawCommitmentHashP h_commitment;
/**
* Index (smaller #TALER_CNC_KAPPA) which the exchange has chosen to not have
* revealed during cut and choose. This value applies to all n coins in the
* commitment.
*/
uint32_t noreveal_index;
/**
* Signature confirming the age withdrawal, matching @e reserve_pub, @e
* maximum_age_group and @e h_commitment and @e total_amount_with_fee.
*/
struct TALER_ReserveSignatureP reserve_sig;
/**
* The exchange's signature of the response.
*/
struct TALER_ExchangeSignatureP sig;
}
/**
* Information the exchange records about a recoup request

2
src/util/exchange_signatures.c
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@ -359,6 +359,8 @@ TALER_exchange_online_melt_confirmation_verify (
}
/* TODO:oec: add signature for age-withdraw and reveal */
GNUNET_NETWORK_STRUCT_BEGIN
/**