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recoup logic review, very minor cleanup

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This commit is contained in:
Christian Grothoff 2020-03-23 13:24:33 +01:00
parent 67cf9747a5
commit bab34d15fc
No known key found for this signature in database
GPG Key ID: 939E6BE1E29FC3CC
1 changed files with 57 additions and 78 deletions
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113
src/exchange/taler-exchange-httpd_recoup.c
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@ -1,6 +1,6 @@
/*
This file is part of TALER
Copyright (C) 2017 Taler Systems SA
Copyright (C) 2017-2020 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
@ -33,50 +33,6 @@
#include "taler-exchange-httpd_keystate.h"
/**
* A wallet asked for /recoup (refresh variant), return the successful
* response.
*
* @param connection connection to the client
* @param old_coin_pub public key of the old coin that will receive the recoup
* @return MHD result code
*/
static int
reply_recoup_refresh_success (struct MHD_Connection *connection,
const struct
TALER_CoinSpendPublicKeyP *old_coin_pub)
{
return TALER_MHD_reply_json_pack (connection,
MHD_HTTP_OK,
"{s:o, s:b}",
"old_coin_pub",
GNUNET_JSON_from_data_auto (
old_coin_pub),
"refreshed", 1);
}
/**
* A wallet asked for /recoup (withdraw variant), return the successful
* response.
*
* @param connection connection to the client
* @param reserve_pub public key of the reserve that will receive the recoup
* @return MHD result code
*/
static int
reply_recoup_success (struct MHD_Connection *connection,
const struct TALER_ReservePublicKeyP *reserve_pub)
{
return TALER_MHD_reply_json_pack (connection,
MHD_HTTP_OK,
"{s:o, s:b}",
"reserve_pub",
GNUNET_JSON_from_data_auto (reserve_pub),
"refreshed", 0);
}
/**
* Closure for #recoup_transaction.
*/
@ -107,6 +63,10 @@ struct RecoupContext
*/
const struct TALER_CoinSpendSignatureP *coin_sig;
/**
* Where does the value of the recouped coin go? Which member
* of the union is valid depends on @e refreshed.
*/
union
{
/**
@ -142,7 +102,7 @@ struct RecoupContext
/**
* Execute a "/recoup". The validity of the coin and signature have
* Execute a "recoup". The validity of the coin and signature have
* already been checked. The database must now check that the coin is
* not (double) spent, and execute the transaction.
*
@ -170,7 +130,7 @@ recoup_transaction (void *cls,
struct TALER_Amount spent;
struct TALER_Amount recouped;
enum GNUNET_DB_QueryStatus qs;
int existing_recoup_found = GNUNET_NO;
int existing_recoup_found;
/* Check whether a recoup is allowed, and if so, to which
reserve / account the money should go */
@ -220,7 +180,7 @@ recoup_transaction (void *cls,
*mhd_ret = TALER_MHD_reply_with_error (connection,
MHD_HTTP_NOT_FOUND,
TALER_EC_RECOUP_WITHDRAW_NOT_FOUND,
"blind coin unknown");
"envelope unknown");
return GNUNET_DB_STATUS_HARD_ERROR;
}
@ -238,7 +198,7 @@ recoup_transaction (void *cls,
*mhd_ret = TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_RECOUP_DB_FETCH_FAILED,
"failed to fetch old coin transaction history");
"failed to fetch coin transaction history");
}
return qs;
}
@ -250,6 +210,7 @@ recoup_transaction (void *cls,
TALER_amount_get_zero (pc->value.currency,
&recouped));
/* Check if this coin has been recouped already at least once */
existing_recoup_found = GNUNET_NO;
for (struct TALER_EXCHANGEDB_TransactionList *pos = tl;
NULL != pos;
pos = pos->next)
@ -292,17 +253,20 @@ recoup_transaction (void *cls,
*mhd_ret = TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_RECOUP_COIN_BALANCE_NEGATIVE,
"calculated negative old coin balance");
"calculated negative coin balance");
return GNUNET_DB_STATUS_HARD_ERROR;
}
if ( (0 == pc->amount.fraction) &&
(0 == pc->amount.value) )
{
/* Recoup has no effect: coin fully spent! */
int ret;
TEH_plugin->rollback (TEH_plugin->cls,
session);
if (GNUNET_NO == existing_recoup_found)
{
/* Refuse: insufficient funds for recoup */
*mhd_ret = TEH_RESPONSE_reply_coin_insufficient_funds (connection,
TALER_EC_RECOUP_COIN_BALANCE_ZERO,
&pc->coin->coin_pub,
@ -312,7 +276,7 @@ recoup_transaction (void *cls,
else
{
/* We didn't add any new recoup transaction, but there was at least
one recoup before, so we give a success response. */
one recoup before, so we give a success response (idempotency!) */
ret = GNUNET_DB_STATUS_SUCCESS_NO_RESULTS;
}
TEH_plugin->free_coin_transaction_list (TEH_plugin->cls,
@ -352,7 +316,7 @@ recoup_transaction (void *cls,
{
if (GNUNET_DB_STATUS_HARD_ERROR == qs)
{
TALER_LOG_WARNING ("Failed to store /recoup information in database\n");
TALER_LOG_WARNING ("Failed to store recoup information in database\n");
*mhd_ret = TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_RECOUP_DB_PUT_FAILED,
@ -369,7 +333,7 @@ recoup_transaction (void *cls,
* some basic sanity checks (especially that the signature on the
* request and coin is valid) and then execute the recoup operation.
* Note that we need the DB to check the fee structure, so this is not
* done here.
* done here but during the recoup_transaction().
*
* @param connection the MHD connection to handle
* @param coin information about the coin
@ -388,7 +352,6 @@ verify_and_execute_recoup (struct MHD_Connection *connection,
{
struct RecoupContext pc;
const struct TALER_EXCHANGEDB_DenominationKey *dki;
struct TALER_RecoupRequestPS pr;
struct GNUNET_HashCode c_hash;
void *coin_ev;
size_t coin_ev_size;
@ -417,11 +380,11 @@ verify_and_execute_recoup (struct MHD_Connection *connection,
{
TEH_KS_release (key_state);
TALER_LOG_WARNING (
"Denomination key in /recoup request not in recoup mode\n");
"Denomination key in recoup request not in recoup mode\n");
return TALER_MHD_reply_with_error (connection,
hc,
ec,
"denomination not allowing recoup");
"denomination not valid for recoup");
}
TALER_amount_ntoh (&pc.value,
&dki->issue.properties.value);
@ -431,7 +394,7 @@ verify_and_execute_recoup (struct MHD_Connection *connection,
TALER_test_coin_valid (coin,
&dki->denom_pub))
{
TALER_LOG_WARNING ("Invalid coin passed for /recoup\n");
TALER_LOG_WARNING ("Invalid coin passed for recoup\n");
TEH_KS_release (key_state);
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_FORBIDDEN,
@ -440,11 +403,14 @@ verify_and_execute_recoup (struct MHD_Connection *connection,
}
/* check recoup request signature */
pr.purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_RECOUP);
pr.purpose.size = htonl (sizeof (struct TALER_RecoupRequestPS));
pr.coin_pub = coin->coin_pub;
pr.h_denom_pub = dki->issue.properties.denom_hash;
pr.coin_blind = *coin_bks;
{
struct TALER_RecoupRequestPS pr = {
.purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_RECOUP),
.purpose.size = htonl (sizeof (struct TALER_RecoupRequestPS)),
.coin_pub = coin->coin_pub,
.h_denom_pub = dki->issue.properties.denom_hash,
.coin_blind = *coin_bks
};
if (GNUNET_OK !=
GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_WALLET_COIN_RECOUP,
@ -452,13 +418,14 @@ verify_and_execute_recoup (struct MHD_Connection *connection,
&coin_sig->eddsa_signature,
&coin->coin_pub.eddsa_pub))
{
TALER_LOG_WARNING ("Invalid signature on /recoup request\n");
TALER_LOG_WARNING ("Invalid signature on recoup request\n");
TEH_KS_release (key_state);
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_FORBIDDEN,
TALER_EC_RECOUP_SIGNATURE_INVALID,
"coin_sig");
}
}
GNUNET_CRYPTO_hash (&coin->coin_pub.eddsa_pub,
sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey),
&c_hash);
@ -499,6 +466,7 @@ verify_and_execute_recoup (struct MHD_Connection *connection,
return mhd_ret;
}
/* Perform actual recoup transaction */
pc.coin_sig = coin_sig;
pc.coin_bks = coin_bks;
pc.coin = coin;
@ -514,11 +482,22 @@ verify_and_execute_recoup (struct MHD_Connection *connection,
&pc))
return mhd_ret;
}
/* Recoup succeeded, return result */
return (refreshed)
? reply_recoup_refresh_success (connection,
&pc.target.old_coin_pub)
: reply_recoup_success (connection,
&pc.target.reserve_pub);
? TALER_MHD_reply_json_pack (connection,
MHD_HTTP_OK,
"{s:o, s:b}",
"old_coin_pub",
GNUNET_JSON_from_data_auto (
&pc.target.old_coin_pub),
"refreshed", 1)
: TALER_MHD_reply_json_pack (connection,
MHD_HTTP_OK,
"{s:o, s:b}",
"reserve_pub",
GNUNET_JSON_from_data_auto (
&pc.target.reserve_pub),
"refreshed", 0);
}