/*
This file is part of TALER
Copyright (C) 2014-2023 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
*/
/**
* @file taler-auditor-httpd_deposit-confirmation.c
* @brief Handle /deposit-confirmation requests; parses the POST and JSON and
* verifies the coin signature before handing things off
* to the database.
* @author Christian Grothoff
*/
#include "platform.h"
#include
#include
#include
#include
#include
#include "taler_json_lib.h"
#include "taler_mhd_lib.h"
#include "taler-auditor-httpd.h"
#include "taler-auditor-httpd_deposit-confirmation.h"
GNUNET_NETWORK_STRUCT_BEGIN
/**
* @brief Information about a signing key of the exchange. Signing keys are used
* to sign exchange messages other than coins, i.e. to confirm that a
* deposit was successful or that a refresh was accepted.
*/
struct ExchangeSigningKeyDataP
{
/**
* When does this signing key begin to be valid?
*/
struct GNUNET_TIME_TimestampNBO start;
/**
* When does this signing key expire? Note: This is currently when
* the Exchange will definitively stop using it. Signatures made with
* the key remain valid until @e end. When checking validity periods,
* clients should allow for some overlap between keys and tolerate
* the use of either key during the overlap time (due to the
* possibility of clock skew).
*/
struct GNUNET_TIME_TimestampNBO expire;
/**
* When do signatures with this signing key become invalid? After
* this point, these signatures cannot be used in (legal) disputes
* anymore, as the Exchange is then allowed to destroy its side of the
* evidence. @e end is expected to be significantly larger than @e
* expire (by a year or more).
*/
struct GNUNET_TIME_TimestampNBO end;
/**
* The public online signing key that the exchange will use
* between @e start and @e expire.
*/
struct TALER_ExchangePublicKeyP signkey_pub;
};
GNUNET_NETWORK_STRUCT_END
/**
* Cache of already verified exchange signing keys. Maps the hash of the
* `struct TALER_ExchangeSigningKeyValidityPS` to the (static) string
* "verified" or "revoked". Access to this map is guarded by the #lock.
*/
static struct GNUNET_CONTAINER_MultiHashMap *cache;
/**
* Lock for operations on #cache.
*/
static pthread_mutex_t lock;
/**
* We have parsed the JSON information about the deposit, do some
* basic sanity checks (especially that the signature on the coin is
* valid, and that this type of coin exists) and then execute the
* deposit.
*
* @param connection the MHD connection to handle
* @param dc information about the deposit confirmation
* @param es information about the exchange's signing key
* @return MHD result code
*/
static MHD_RESULT
verify_and_execute_deposit_confirmation (
struct MHD_Connection *connection,
const struct TALER_AUDITORDB_DepositConfirmation *dc,
const struct TALER_AUDITORDB_ExchangeSigningKey *es)
{
enum GNUNET_DB_QueryStatus qs;
struct GNUNET_HashCode h;
const char *cached;
struct ExchangeSigningKeyDataP skv = {
.start = GNUNET_TIME_timestamp_hton (es->ep_start),
.expire = GNUNET_TIME_timestamp_hton (es->ep_expire),
.end = GNUNET_TIME_timestamp_hton (es->ep_end),
.signkey_pub = es->exchange_pub
};
const struct TALER_CoinSpendSignatureP *coin_sigps[
GNUNET_NZL (dc->num_coins)];
for (unsigned int i = 0; i < dc->num_coins; i++)
coin_sigps[i] = &dc->coin_sigs[i];
if (GNUNET_TIME_absolute_is_future (es->ep_start.abs_time) ||
GNUNET_TIME_absolute_is_past (es->ep_expire.abs_time))
{
/* Signing key expired */
TALER_LOG_WARNING ("Expired exchange signing key\n");
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_FORBIDDEN,
TALER_EC_AUDITOR_DEPOSIT_CONFIRMATION_SIGNATURE_INVALID,
"master signature expired");
}
/* check our cache */
GNUNET_CRYPTO_hash (&skv,
sizeof(skv),
&h);
GNUNET_assert (0 == pthread_mutex_lock (&lock));
cached = GNUNET_CONTAINER_multihashmap_get (cache,
&h);
GNUNET_assert (0 == pthread_mutex_unlock (&lock));
if (GNUNET_SYSERR ==
TAH_plugin->preflight (TAH_plugin->cls))
{
GNUNET_break (0);
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_GENERIC_DB_SETUP_FAILED,
NULL);
}
if (NULL == cached)
{
/* Not in cache, need to verify the signature, persist it, and possibly cache it */
if (GNUNET_OK !=
TALER_exchange_offline_signkey_validity_verify (
&es->exchange_pub,
es->ep_start,
es->ep_expire,
es->ep_end,
&TAH_master_public_key,
&es->master_sig))
{
TALER_LOG_WARNING ("Invalid signature on exchange signing key\n");
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_FORBIDDEN,
TALER_EC_AUDITOR_DEPOSIT_CONFIRMATION_SIGNATURE_INVALID,
"master signature invalid");
}
/* execute transaction */
qs = TAH_plugin->insert_exchange_signkey (TAH_plugin->cls,
es);
if (0 > qs)
{
GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR == qs);
TALER_LOG_WARNING ("Failed to store exchange signing key in database\n");
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_GENERIC_DB_STORE_FAILED,
"exchange signing key");
}
cached = "verified";
}
if (0 == strcmp (cached,
"verified"))
{
struct TALER_MasterSignatureP master_sig;
/* check for revocation */
qs = TAH_eplugin->lookup_signkey_revocation (TAH_eplugin->cls,
&es->exchange_pub,
&master_sig);
if (0 > qs)
{
GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR == qs);
TALER_LOG_WARNING (
"Failed to check for signing key revocation in database\n");
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_GENERIC_DB_FETCH_FAILED,
"exchange signing key revocation");
}
if (0 < qs)
cached = "revoked";
}
/* Cache it, due to concurreny it might already be in the cache,
so we do not cache it twice but also don't insist on the 'put' to
succeed. */
GNUNET_assert (0 == pthread_mutex_lock (&lock));
(void) GNUNET_CONTAINER_multihashmap_put (cache,
&h,
(void *) cached,
GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
GNUNET_assert (0 == pthread_mutex_unlock (&lock));
if (0 == strcmp (cached,
"revoked"))
{
TALER_LOG_WARNING (
"Invalid signature on /deposit-confirmation request: key was revoked\n");
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_GONE,
TALER_EC_AUDITOR_EXCHANGE_SIGNING_KEY_REVOKED,
"exchange signing key was revoked");
}
/* check deposit confirmation signature */
if (GNUNET_OK !=
TALER_exchange_online_deposit_confirmation_verify (
&dc->h_contract_terms,
&dc->h_wire,
&dc->h_policy,
dc->exchange_timestamp,
dc->wire_deadline,
dc->refund_deadline,
&dc->total_without_fee,
dc->num_coins,
coin_sigps,
&dc->merchant,
&dc->exchange_pub,
&dc->exchange_sig))
{
TALER_LOG_WARNING (
"Invalid signature on /deposit-confirmation request\n");
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_FORBIDDEN,
TALER_EC_AUDITOR_DEPOSIT_CONFIRMATION_SIGNATURE_INVALID,
"exchange signature invalid");
}
/* execute transaction */
qs = TAH_plugin->insert_deposit_confirmation (TAH_plugin->cls,
dc);
if (0 > qs)
{
GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR == qs);
TALER_LOG_WARNING ("Failed to store /deposit-confirmation in database\n");
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_GENERIC_DB_STORE_FAILED,
"deposit confirmation");
}
return TALER_MHD_REPLY_JSON_PACK (connection,
MHD_HTTP_OK,
GNUNET_JSON_pack_string ("status",
"DEPOSIT_CONFIRMATION_OK"));
}
MHD_RESULT
TAH_DEPOSIT_CONFIRMATION_handler (
struct TAH_RequestHandler *rh,
struct MHD_Connection *connection,
void **connection_cls,
const char *upload_data,
size_t *upload_data_size,
const char *const args[])
{
struct TALER_AUDITORDB_DepositConfirmation dc = {
.refund_deadline = GNUNET_TIME_UNIT_ZERO_TS
};
struct TALER_AUDITORDB_ExchangeSigningKey es;
const json_t *jcoin_sigs;
const json_t *jcoin_pubs;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("h_contract_terms",
&dc.h_contract_terms),
GNUNET_JSON_spec_fixed_auto ("h_policy",
&dc.h_policy),
GNUNET_JSON_spec_fixed_auto ("h_wire",
&dc.h_wire),
GNUNET_JSON_spec_timestamp ("exchange_timestamp",
&dc.exchange_timestamp),
GNUNET_JSON_spec_mark_optional (
GNUNET_JSON_spec_timestamp ("refund_deadline",
&dc.refund_deadline),
NULL),
GNUNET_JSON_spec_timestamp ("wire_deadline",
&dc.wire_deadline),
TALER_JSON_spec_amount ("total_without_fee",
TAH_currency,
&dc.total_without_fee),
GNUNET_JSON_spec_array_const ("coin_pubs",
&jcoin_pubs),
GNUNET_JSON_spec_array_const ("coin_sigs",
&jcoin_sigs),
GNUNET_JSON_spec_fixed_auto ("merchant_pub",
&dc.merchant),
GNUNET_JSON_spec_fixed_auto ("exchange_sig",
&dc.exchange_sig),
GNUNET_JSON_spec_fixed_auto ("exchange_pub",
&dc.exchange_pub),
GNUNET_JSON_spec_timestamp ("ep_start",
&es.ep_start),
GNUNET_JSON_spec_timestamp ("ep_expire",
&es.ep_expire),
GNUNET_JSON_spec_timestamp ("ep_end",
&es.ep_end),
GNUNET_JSON_spec_fixed_auto ("master_sig",
&es.master_sig),
GNUNET_JSON_spec_end ()
};
unsigned int num_coins;
json_t *json;
(void) rh;
(void) connection_cls;
(void) upload_data;
(void) upload_data_size;
{
enum GNUNET_GenericReturnValue res;
res = TALER_MHD_parse_post_json (connection,
connection_cls,
upload_data,
upload_data_size,
&json);
if (GNUNET_SYSERR == res)
return MHD_NO;
if ((GNUNET_NO == res) ||
(NULL == json))
return MHD_YES;
dc.master_sig = es.master_sig;
res = TALER_MHD_parse_json_data (connection,
json,
spec);
if (GNUNET_SYSERR == res)
{
json_decref (json);
return MHD_NO; /* hard failure */
}
if (GNUNET_NO == res)
{
json_decref (json);
return MHD_YES; /* failure */
}
}
num_coins = json_array_size (jcoin_sigs);
if (num_coins != json_array_size (jcoin_pubs))
{
GNUNET_break_op (0);
json_decref (json);
return TALER_MHD_reply_with_ec (
connection,
TALER_EC_GENERIC_PARAMETER_MALFORMED,
"coin_pubs.length != coin_sigs.length");
}
if (0 == num_coins)
{
GNUNET_break_op (0);
json_decref (json);
return TALER_MHD_reply_with_ec (
connection,
TALER_EC_GENERIC_PARAMETER_MALFORMED,
"coin_pubs array is empty");
}
{
struct TALER_CoinSpendPublicKeyP coin_pubs[num_coins];
struct TALER_CoinSpendSignatureP coin_sigs[num_coins];
MHD_RESULT res;
for (unsigned int i = 0; i < num_coins; i++)
{
json_t *jpub = json_array_get (jcoin_pubs,
i);
json_t *jsig = json_array_get (jcoin_sigs,
i);
const char *ps = json_string_value (jpub);
const char *ss = json_string_value (jsig);
if ((NULL == ps) ||
(GNUNET_OK !=
GNUNET_STRINGS_string_to_data (ps,
strlen (ps),
&coin_pubs[i],
sizeof(coin_pubs[i]))))
{
GNUNET_break_op (0);
json_decref (json);
return TALER_MHD_reply_with_ec (
connection,
TALER_EC_GENERIC_PARAMETER_MALFORMED,
"coin_pub[] malformed");
}
if ((NULL == ss) ||
(GNUNET_OK !=
GNUNET_STRINGS_string_to_data (ss,
strlen (ss),
&coin_sigs[i],
sizeof(coin_sigs[i]))))
{
GNUNET_break_op (0);
json_decref (json);
return TALER_MHD_reply_with_ec (
connection,
TALER_EC_GENERIC_PARAMETER_MALFORMED,
"coin_sig[] malformed");
}
}
dc.num_coins = num_coins;
dc.coin_pubs = coin_pubs;
dc.coin_sigs = coin_sigs;
es.exchange_pub = dc.exchange_pub; /* used twice! */
res = verify_and_execute_deposit_confirmation (connection,
&dc,
&es);
GNUNET_JSON_parse_free (spec);
json_decref (json);
return res;
}
}
void
TEAH_DEPOSIT_CONFIRMATION_init (void)
{
cache = GNUNET_CONTAINER_multihashmap_create (32,
GNUNET_NO);
GNUNET_assert (0 == pthread_mutex_init (&lock, NULL));
}
void
TEAH_DEPOSIT_CONFIRMATION_done (void)
{
if (NULL != cache)
{
GNUNET_CONTAINER_multihashmap_destroy (cache);
cache = NULL;
GNUNET_assert (0 == pthread_mutex_destroy (&lock));
}
}