501 lines
16 KiB
C
501 lines
16 KiB
C
/*
|
|
This file is part of TALER
|
|
Copyright (C) 2015-2021 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_refreshes_reveal.c
|
|
* @brief Implementation of the /refreshes/$RCH/reveal requests
|
|
* @author Christian Grothoff
|
|
*/
|
|
#include "platform.h"
|
|
#include <jansson.h>
|
|
#include <microhttpd.h> /* just for HTTP status codes */
|
|
#include <gnunet/gnunet_util_lib.h>
|
|
#include <gnunet/gnunet_json_lib.h>
|
|
#include <gnunet/gnunet_curl_lib.h>
|
|
#include "taler_json_lib.h"
|
|
#include "taler_exchange_service.h"
|
|
#include "exchange_api_handle.h"
|
|
#include "taler_signatures.h"
|
|
#include "exchange_api_curl_defaults.h"
|
|
#include "exchange_api_refresh_common.h"
|
|
|
|
|
|
/**
|
|
* @brief A /refreshes/$RCH/reveal Handle
|
|
*/
|
|
struct TALER_EXCHANGE_RefreshesRevealHandle
|
|
{
|
|
|
|
/**
|
|
* 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_RefreshesRevealCallback reveal_cb;
|
|
|
|
/**
|
|
* Closure for @e reveal_cb.
|
|
*/
|
|
void *reveal_cb_cls;
|
|
|
|
/**
|
|
* Actual information about the melt operation.
|
|
*/
|
|
struct MeltData *md;
|
|
|
|
/**
|
|
* The index selected by the exchange in cut-and-choose to not be revealed.
|
|
*/
|
|
uint16_t noreveal_index;
|
|
|
|
};
|
|
|
|
|
|
/**
|
|
* We got a 200 OK response for the /refreshes/$RCH/reveal operation.
|
|
* Extract the coin signatures and return them to the caller.
|
|
* The signatures we get from the exchange is for the blinded value.
|
|
* Thus, we first must unblind them and then should verify their
|
|
* validity.
|
|
*
|
|
* If everything checks out, we return the unblinded signatures
|
|
* to the application via the callback.
|
|
*
|
|
* @param rrh operation handle
|
|
* @param json reply from the exchange
|
|
* @param[out] sigs array of length `num_fresh_coins`, initialized to contain RSA signatures
|
|
* @return #GNUNET_OK on success, #GNUNET_SYSERR on errors
|
|
*/
|
|
static enum GNUNET_GenericReturnValue
|
|
refresh_reveal_ok (struct TALER_EXCHANGE_RefreshesRevealHandle *rrh,
|
|
const json_t *json,
|
|
struct TALER_DenominationSignature *sigs)
|
|
{
|
|
json_t *jsona;
|
|
struct GNUNET_JSON_Specification outer_spec[] = {
|
|
GNUNET_JSON_spec_json ("ev_sigs",
|
|
&jsona),
|
|
GNUNET_JSON_spec_end ()
|
|
};
|
|
|
|
if (GNUNET_OK !=
|
|
GNUNET_JSON_parse (json,
|
|
outer_spec,
|
|
NULL, NULL))
|
|
{
|
|
GNUNET_break_op (0);
|
|
return GNUNET_SYSERR;
|
|
}
|
|
if (! json_is_array (jsona))
|
|
{
|
|
/* We expected an array of coins */
|
|
GNUNET_break_op (0);
|
|
GNUNET_JSON_parse_free (outer_spec);
|
|
return GNUNET_SYSERR;
|
|
}
|
|
if (rrh->md->num_fresh_coins != json_array_size (jsona))
|
|
{
|
|
/* Number of coins generated does not match our expectation */
|
|
GNUNET_break_op (0);
|
|
GNUNET_JSON_parse_free (outer_spec);
|
|
return GNUNET_SYSERR;
|
|
}
|
|
for (unsigned int i = 0; i<rrh->md->num_fresh_coins; i++)
|
|
{
|
|
const struct TALER_PlanchetSecretsP *fc;
|
|
struct TALER_DenominationPublicKey *pk;
|
|
json_t *jsonai;
|
|
struct TALER_BlindedDenominationSignature blind_sig;
|
|
struct TALER_CoinSpendPublicKeyP coin_pub;
|
|
struct TALER_CoinPubHash coin_hash;
|
|
struct GNUNET_JSON_Specification spec[] = {
|
|
TALER_JSON_spec_blinded_denom_sig ("ev_sig",
|
|
&blind_sig),
|
|
GNUNET_JSON_spec_end ()
|
|
};
|
|
struct TALER_FreshCoin coin;
|
|
|
|
fc = &rrh->md->fresh_coins[rrh->noreveal_index][i];
|
|
pk = &rrh->md->fresh_pks[i];
|
|
jsonai = json_array_get (jsona, i);
|
|
GNUNET_assert (NULL != jsonai);
|
|
|
|
if (GNUNET_OK !=
|
|
GNUNET_JSON_parse (jsonai,
|
|
spec,
|
|
NULL, NULL))
|
|
{
|
|
GNUNET_break_op (0);
|
|
GNUNET_JSON_parse_free (outer_spec);
|
|
return GNUNET_SYSERR;
|
|
}
|
|
|
|
/* needed to verify the signature, and we didn't store it earlier,
|
|
hence recomputing it here... */
|
|
GNUNET_CRYPTO_eddsa_key_get_public (&fc->coin_priv.eddsa_priv,
|
|
&coin_pub.eddsa_pub);
|
|
/* FIXME-Oec: Age commitment hash. */
|
|
TALER_coin_pub_hash (&coin_pub,
|
|
NULL, /* FIXME-Oec */
|
|
&coin_hash);
|
|
if (GNUNET_OK !=
|
|
TALER_planchet_to_coin (pk,
|
|
&blind_sig,
|
|
fc,
|
|
&coin_hash,
|
|
&coin))
|
|
{
|
|
GNUNET_break_op (0);
|
|
GNUNET_JSON_parse_free (spec);
|
|
GNUNET_JSON_parse_free (outer_spec);
|
|
return GNUNET_SYSERR;
|
|
}
|
|
GNUNET_JSON_parse_free (spec);
|
|
sigs[i] = coin.sig;
|
|
}
|
|
GNUNET_JSON_parse_free (outer_spec);
|
|
return GNUNET_OK;
|
|
}
|
|
|
|
|
|
/**
|
|
* Function called when we're done processing the
|
|
* HTTP /refreshes/$RCH/reveal request.
|
|
*
|
|
* @param cls the `struct TALER_EXCHANGE_RefreshHandle`
|
|
* @param response_code HTTP response code, 0 on error
|
|
* @param response parsed JSON result, NULL on error
|
|
*/
|
|
static void
|
|
handle_refresh_reveal_finished (void *cls,
|
|
long response_code,
|
|
const void *response)
|
|
{
|
|
struct TALER_EXCHANGE_RefreshesRevealHandle *rrh = cls;
|
|
const json_t *j = response;
|
|
struct TALER_EXCHANGE_HttpResponse hr = {
|
|
.reply = j,
|
|
.http_status = (unsigned int) response_code
|
|
};
|
|
|
|
rrh->job = NULL;
|
|
switch (response_code)
|
|
{
|
|
case 0:
|
|
hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
|
|
break;
|
|
case MHD_HTTP_OK:
|
|
{
|
|
struct TALER_DenominationSignature sigs[rrh->md->num_fresh_coins];
|
|
int ret;
|
|
|
|
memset (sigs,
|
|
0,
|
|
sizeof (sigs));
|
|
ret = refresh_reveal_ok (rrh,
|
|
j,
|
|
sigs);
|
|
if (GNUNET_OK != ret)
|
|
{
|
|
hr.http_status = 0;
|
|
hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
|
|
}
|
|
else
|
|
{
|
|
rrh->reveal_cb (rrh->reveal_cb_cls,
|
|
&hr,
|
|
rrh->md->num_fresh_coins,
|
|
rrh->md->fresh_coins[rrh->noreveal_index],
|
|
sigs);
|
|
rrh->reveal_cb = NULL;
|
|
}
|
|
for (unsigned int i = 0; i<rrh->md->num_fresh_coins; i++)
|
|
TALER_denom_sig_free (&sigs[i]);
|
|
TALER_EXCHANGE_refreshes_reveal_cancel (rrh);
|
|
return;
|
|
}
|
|
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 */
|
|
hr.ec = TALER_JSON_get_error_code (j);
|
|
hr.hint = TALER_JSON_get_error_hint (j);
|
|
break;
|
|
case MHD_HTTP_CONFLICT:
|
|
/* Nothing really to verify, exchange says our reveal is inconsistent
|
|
with our commitment, so either side is buggy; we
|
|
should pass the JSON reply to the application */
|
|
hr.ec = TALER_JSON_get_error_code (j);
|
|
hr.hint = TALER_JSON_get_error_hint (j);
|
|
break;
|
|
case MHD_HTTP_GONE:
|
|
/* Server claims key expired or has been revoked */
|
|
hr.ec = TALER_JSON_get_error_code (j);
|
|
hr.hint = TALER_JSON_get_error_hint (j);
|
|
break;
|
|
case MHD_HTTP_INTERNAL_SERVER_ERROR:
|
|
/* Server had an internal issue; we should retry, but this API
|
|
leaves this to the application */
|
|
hr.ec = TALER_JSON_get_error_code (j);
|
|
hr.hint = TALER_JSON_get_error_hint (j);
|
|
break;
|
|
default:
|
|
/* unexpected response code */
|
|
GNUNET_break_op (0);
|
|
hr.ec = TALER_JSON_get_error_code (j);
|
|
hr.hint = TALER_JSON_get_error_hint (j);
|
|
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
|
|
"Unexpected response code %u/%d for exchange refreshes reveal\n",
|
|
(unsigned int) response_code,
|
|
(int) hr.ec);
|
|
break;
|
|
}
|
|
if (NULL != rrh->reveal_cb)
|
|
rrh->reveal_cb (rrh->reveal_cb_cls,
|
|
&hr,
|
|
0,
|
|
NULL,
|
|
NULL);
|
|
TALER_EXCHANGE_refreshes_reveal_cancel (rrh);
|
|
}
|
|
|
|
|
|
struct TALER_EXCHANGE_RefreshesRevealHandle *
|
|
TALER_EXCHANGE_refreshes_reveal (
|
|
struct TALER_EXCHANGE_Handle *exchange,
|
|
const json_t *refresh_data,
|
|
uint32_t noreveal_index,
|
|
TALER_EXCHANGE_RefreshesRevealCallback reveal_cb,
|
|
void *reveal_cb_cls)
|
|
{
|
|
struct TALER_EXCHANGE_RefreshesRevealHandle *rrh;
|
|
json_t *transfer_privs;
|
|
json_t *new_denoms_h;
|
|
json_t *coin_evs;
|
|
json_t *reveal_obj;
|
|
json_t *link_sigs;
|
|
CURL *eh;
|
|
struct GNUNET_CURL_Context *ctx;
|
|
struct MeltData *md;
|
|
struct TALER_TransferPublicKeyP transfer_pub;
|
|
char arg_str[sizeof (struct TALER_RefreshCommitmentP) * 2 + 32];
|
|
|
|
if (noreveal_index >= TALER_CNC_KAPPA)
|
|
{
|
|
/* We check this here, as it would be really bad to below just
|
|
disclose all the transfer keys. Note that this error should
|
|
have been caught way earlier when the exchange replied, but maybe
|
|
we had some internal corruption that changed the value... */
|
|
GNUNET_break (0);
|
|
return NULL;
|
|
}
|
|
if (GNUNET_YES !=
|
|
TEAH_handle_is_ready (exchange))
|
|
{
|
|
GNUNET_break (0);
|
|
return NULL;
|
|
}
|
|
md = TALER_EXCHANGE_deserialize_melt_data_ (refresh_data,
|
|
exchange->key_data.currency);
|
|
if (NULL == md)
|
|
{
|
|
GNUNET_break (0);
|
|
return NULL;
|
|
}
|
|
|
|
/* now transfer_pub */
|
|
GNUNET_CRYPTO_ecdhe_key_get_public (
|
|
&md->melted_coin.transfer_priv[noreveal_index].ecdhe_priv,
|
|
&transfer_pub.ecdhe_pub);
|
|
|
|
/* now new_denoms */
|
|
GNUNET_assert (NULL != (new_denoms_h = json_array ()));
|
|
GNUNET_assert (NULL != (coin_evs = json_array ()));
|
|
GNUNET_assert (NULL != (link_sigs = json_array ()));
|
|
for (unsigned int i = 0; i<md->num_fresh_coins; i++)
|
|
{
|
|
struct TALER_DenominationHash denom_hash;
|
|
struct TALER_PlanchetDetail pd;
|
|
struct TALER_CoinPubHash c_hash;
|
|
|
|
TALER_denom_pub_hash (&md->fresh_pks[i],
|
|
&denom_hash);
|
|
GNUNET_assert (0 ==
|
|
json_array_append_new (new_denoms_h,
|
|
GNUNET_JSON_from_data_auto (
|
|
&denom_hash)));
|
|
|
|
if (GNUNET_OK !=
|
|
TALER_planchet_prepare (&md->fresh_pks[i],
|
|
&md->fresh_coins[noreveal_index][i],
|
|
&c_hash,
|
|
&pd))
|
|
{
|
|
/* This should have been noticed during the preparation stage. */
|
|
GNUNET_break (0);
|
|
json_decref (new_denoms_h);
|
|
json_decref (coin_evs);
|
|
return NULL;
|
|
}
|
|
GNUNET_assert (0 ==
|
|
json_array_append_new (coin_evs,
|
|
GNUNET_JSON_from_data (
|
|
pd.blinded_planchet.details.
|
|
rsa_blinded_planchet.blinded_msg,
|
|
pd.
|
|
blinded_planchet.details.
|
|
rsa_blinded_planchet.
|
|
blinded_msg_size)));
|
|
{
|
|
struct TALER_CoinSpendSignatureP link_sig;
|
|
|
|
TALER_wallet_link_sign (&denom_hash,
|
|
&transfer_pub,
|
|
pd.blinded_planchet.details.rsa_blinded_planchet.
|
|
blinded_msg,
|
|
pd.blinded_planchet.details.rsa_blinded_planchet.
|
|
blinded_msg_size,
|
|
&md->melted_coin.coin_priv,
|
|
&link_sig);
|
|
GNUNET_assert (0 ==
|
|
json_array_append_new (
|
|
link_sigs,
|
|
GNUNET_JSON_from_data_auto (&link_sig)));
|
|
}
|
|
GNUNET_free (pd.blinded_planchet.details.rsa_blinded_planchet.blinded_msg);
|
|
}
|
|
|
|
/* build array of transfer private keys */
|
|
GNUNET_assert (NULL != (transfer_privs = json_array ()));
|
|
for (unsigned int j = 0; j<TALER_CNC_KAPPA; j++)
|
|
{
|
|
if (j == noreveal_index)
|
|
{
|
|
/* This is crucial: exclude the transfer key for the
|
|
noreval index! */
|
|
continue;
|
|
}
|
|
GNUNET_assert (0 ==
|
|
json_array_append_new (transfer_privs,
|
|
GNUNET_JSON_from_data_auto (
|
|
&md->melted_coin.transfer_priv[j])));
|
|
}
|
|
|
|
/* build main JSON request */
|
|
reveal_obj = GNUNET_JSON_PACK (
|
|
GNUNET_JSON_pack_data_auto ("transfer_pub",
|
|
&transfer_pub),
|
|
GNUNET_JSON_pack_array_steal ("transfer_privs",
|
|
transfer_privs),
|
|
GNUNET_JSON_pack_array_steal ("link_sigs",
|
|
link_sigs),
|
|
GNUNET_JSON_pack_array_steal ("new_denoms_h",
|
|
new_denoms_h),
|
|
GNUNET_JSON_pack_array_steal ("coin_evs",
|
|
coin_evs));
|
|
{
|
|
char pub_str[sizeof (struct TALER_RefreshCommitmentP) * 2];
|
|
char *end;
|
|
|
|
end = GNUNET_STRINGS_data_to_string (&md->rc,
|
|
sizeof (struct
|
|
TALER_RefreshCommitmentP),
|
|
pub_str,
|
|
sizeof (pub_str));
|
|
*end = '\0';
|
|
GNUNET_snprintf (arg_str,
|
|
sizeof (arg_str),
|
|
"/refreshes/%s/reveal",
|
|
pub_str);
|
|
}
|
|
/* finally, we can actually issue the request */
|
|
rrh = GNUNET_new (struct TALER_EXCHANGE_RefreshesRevealHandle);
|
|
rrh->exchange = exchange;
|
|
rrh->noreveal_index = noreveal_index;
|
|
rrh->reveal_cb = reveal_cb;
|
|
rrh->reveal_cb_cls = reveal_cb_cls;
|
|
rrh->md = md;
|
|
rrh->url = TEAH_path_to_url (rrh->exchange,
|
|
arg_str);
|
|
if (NULL == rrh->url)
|
|
{
|
|
json_decref (reveal_obj);
|
|
GNUNET_free (rrh);
|
|
return NULL;
|
|
}
|
|
eh = TALER_EXCHANGE_curl_easy_get_ (rrh->url);
|
|
if ( (NULL == eh) ||
|
|
(GNUNET_OK !=
|
|
TALER_curl_easy_post (&rrh->ctx,
|
|
eh,
|
|
reveal_obj)) )
|
|
{
|
|
GNUNET_break (0);
|
|
if (NULL != eh)
|
|
curl_easy_cleanup (eh);
|
|
json_decref (reveal_obj);
|
|
GNUNET_free (rrh->url);
|
|
GNUNET_free (rrh);
|
|
return NULL;
|
|
}
|
|
json_decref (reveal_obj);
|
|
ctx = TEAH_handle_to_context (rrh->exchange);
|
|
rrh->job = GNUNET_CURL_job_add2 (ctx,
|
|
eh,
|
|
rrh->ctx.headers,
|
|
&handle_refresh_reveal_finished,
|
|
rrh);
|
|
return rrh;
|
|
}
|
|
|
|
|
|
void
|
|
TALER_EXCHANGE_refreshes_reveal_cancel (
|
|
struct TALER_EXCHANGE_RefreshesRevealHandle *rrh)
|
|
{
|
|
if (NULL != rrh->job)
|
|
{
|
|
GNUNET_CURL_job_cancel (rrh->job);
|
|
rrh->job = NULL;
|
|
}
|
|
GNUNET_free (rrh->url);
|
|
TALER_curl_easy_post_finished (&rrh->ctx);
|
|
TALER_EXCHANGE_free_melt_data_ (rrh->md); /* does not free 'md' itself */
|
|
GNUNET_free (rrh->md);
|
|
GNUNET_free (rrh);
|
|
}
|
|
|
|
|
|
/* exchange_api_refreshes_reveal.c */
|