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|
/*
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 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_wire.c
* @brief Implementation of the /wire request of the exchange's HTTP API
* @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_curl_lib.h>
#include "taler_exchange_service.h"
#include "taler_json_lib.h"
#include "taler_signatures.h"
#include "exchange_api_handle.h"
#include "exchange_api_curl_defaults.h"
/**
* @brief A Wire Handle
*/
struct TALER_EXCHANGE_WireHandle
{
/**
* The connection to exchange this request handle will use
*/
struct TALER_EXCHANGE_Handle *exchange;
/**
* The url for this request.
*/
char *url;
/**
* Handle for the request.
*/
struct GNUNET_CURL_Job *job;
/**
* Function to call with the result.
*/
TALER_EXCHANGE_WireCallback cb;
/**
* Closure for @a cb.
*/
void *cb_cls;
};
/**
* Frees @a wfm array.
*
* @param wfm fee array to release
* @param wfm_len length of the @a wfm array
*/
static void
free_fees (struct TALER_EXCHANGE_WireFeesByMethod *wfm,
unsigned int wfm_len)
{
for (unsigned int i = 0; i<wfm_len; i++)
{
struct TALER_EXCHANGE_WireFeesByMethod *wfmi = &wfm[i];
while (NULL != wfmi->fees_head)
{
struct TALER_EXCHANGE_WireAggregateFees *fe
= wfmi->fees_head;
wfmi->fees_head = fe->next;
GNUNET_free (fe);
}
}
GNUNET_free (wfm);
}
/**
* Parse wire @a fees and return array.
*
* @param master_pub master public key to use to check signatures
* @param fees json AggregateTransferFee to parse
* @param[out] fees_len set to length of returned array
* @return NULL on error
*/
static struct TALER_EXCHANGE_WireFeesByMethod *
parse_fees (const struct TALER_MasterPublicKeyP *master_pub,
const json_t *fees,
unsigned int *fees_len)
{
struct TALER_EXCHANGE_WireFeesByMethod *fbm;
unsigned int fbml = json_object_size (fees);
unsigned int i = 0;
const char *key;
const json_t *fee_array;
fbm = GNUNET_new_array (fbml,
struct TALER_EXCHANGE_WireFeesByMethod);
*fees_len = fbml;
json_object_foreach ((json_t *) fees, key, fee_array) {
struct TALER_EXCHANGE_WireFeesByMethod *fe = &fbm[i++];
unsigned int idx;
json_t *fee;
fe->method = key;
fe->fees_head = NULL;
json_array_foreach (fee_array, idx, fee)
{
struct TALER_EXCHANGE_WireAggregateFees *wa
= GNUNET_new (struct TALER_EXCHANGE_WireAggregateFees);
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("sig",
&wa->master_sig),
TALER_JSON_spec_amount_any ("wire_fee",
&wa->fees.wire),
TALER_JSON_spec_amount_any ("closing_fee",
&wa->fees.closing),
GNUNET_JSON_spec_timestamp ("start_date",
&wa->start_date),
GNUNET_JSON_spec_timestamp ("end_date",
&wa->end_date),
GNUNET_JSON_spec_end ()
};
wa->next = fe->fees_head;
fe->fees_head = wa;
if (GNUNET_OK !=
GNUNET_JSON_parse (fee,
spec,
NULL,
NULL))
{
GNUNET_break_op (0);
free_fees (fbm,
i);
return NULL;
}
if (GNUNET_OK !=
TALER_exchange_offline_wire_fee_verify (
key,
wa->start_date,
wa->end_date,
&wa->fees,
master_pub,
&wa->master_sig))
{
GNUNET_break_op (0);
free_fees (fbm,
i);
return NULL;
}
} /* for all fees over time */
} /* for all methods */
GNUNET_assert (i == fbml);
return fbm;
}
/**
* Parse account restriction in @a jrest into @a rest.
*
* @param jrest array of account restrictions in JSON
* @param[out] resta_len set to length of @a resta
* @param[out] resta account restriction array to set
* @return #GNUNET_OK on success
*/
static enum GNUNET_GenericReturnValue
parse_restrictions (const json_t *jresta,
unsigned int *resta_len,
struct TALER_EXCHANGE_AccountRestriction **resta)
{
if (! json_is_array (jresta))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
*resta_len = json_array_size (jresta);
if (0 == *resta_len)
{
/* no restrictions, perfectly OK */
*resta = NULL;
return GNUNET_OK;
}
*resta = GNUNET_new_array (*resta_len,
struct TALER_EXCHANGE_AccountRestriction);
for (unsigned int i = 0; i<*resta_len; i++)
{
const json_t *jr = json_array_get (jresta,
i);
struct TALER_EXCHANGE_AccountRestriction *ar = &(*resta)[i];
const char *type = json_string_value (json_object_get (jr,
"type"));
if (NULL == type)
{
GNUNET_break (0);
goto fail;
}
if (0 == strcmp (type,
"deny"))
{
ar->type = TALER_EXCHANGE_AR_DENY;
continue;
}
if (0 == strcmp (type,
"regex"))
{
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_string (
"payto_regex",
&ar->details.regex.posix_egrep),
GNUNET_JSON_spec_string (
"human_hint",
&ar->details.regex.human_hint),
GNUNET_JSON_spec_mark_optional (
GNUNET_JSON_spec_object_const (
"human_hint_i18n",
&ar->details.regex.human_hint_i18n),
NULL),
GNUNET_JSON_spec_end ()
};
if (GNUNET_OK !=
GNUNET_JSON_parse (jr,
spec,
NULL, NULL))
{
/* bogus reply */
GNUNET_break_op (0);
goto fail;
}
ar->type = TALER_EXCHANGE_AR_REGEX;
continue;
}
/* unsupported type */
GNUNET_break (0);
return GNUNET_SYSERR;
}
return GNUNET_OK;
fail:
GNUNET_free (*resta);
*resta_len = 0;
return GNUNET_SYSERR;
}
/**
* Free data within @a was, but not @a was itself.
*
* @param was array of wire account data
* @param was_len length of the @a was array
*/
static void
free_accounts (struct TALER_EXCHANGE_WireAccount *was,
unsigned int was_len)
{
for (unsigned int i = 0; i<was_len; i++)
{
struct TALER_EXCHANGE_WireAccount *wa = &was[i];
GNUNET_free (wa->credit_restrictions);
GNUNET_free (wa->debit_restrictions);
}
}
/**
* Function called when we're done processing the
* HTTP /wire request.
*
* @param cls the `struct TALER_EXCHANGE_WireHandle`
* @param response_code HTTP response code, 0 on error
* @param response parsed JSON result, NULL on error
*/
static void
handle_wire_finished (void *cls,
long response_code,
const void *response)
{
struct TALER_EXCHANGE_WireHandle *wh = cls;
const json_t *j = response;
struct TALER_EXCHANGE_WireResponse wr = {
.hr.reply = j,
.hr.http_status = (unsigned int) response_code
};
TALER_LOG_DEBUG ("Checking raw /wire response\n");
wh->job = NULL;
switch (response_code)
{
case 0:
wr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
wh->exchange->wire_error_count++;
break;
case MHD_HTTP_OK:
{
const json_t *accounts;
const json_t *fees;
const json_t *wads;
struct TALER_EXCHANGE_WireFeesByMethod *fbm;
struct TALER_MasterPublicKeyP master_pub;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_fixed_auto ("master_public_key",
&master_pub),
GNUNET_JSON_spec_array_const ("accounts",
&accounts),
GNUNET_JSON_spec_object_const ("fees",
&fees),
GNUNET_JSON_spec_array_const ("wads",
&wads),
GNUNET_JSON_spec_end ()
};
wh->exchange->wire_error_count = 0;
if (GNUNET_OK !=
GNUNET_JSON_parse (j,
spec,
NULL, NULL))
{
/* bogus reply */
GNUNET_break_op (0);
wr.hr.http_status = 0;
wr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
break;
}
{
const struct TALER_EXCHANGE_Keys *key_state;
key_state = TALER_EXCHANGE_get_keys (wh->exchange);
if (0 != GNUNET_memcmp (&key_state->master_pub,
&master_pub))
{
/* bogus reply: master public key in /wire differs from that in /keys */
GNUNET_break_op (0);
wr.hr.http_status = 0;
wr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
break;
}
}
wr.details.ok.accounts_len
= json_array_size (accounts);
if (0 == wr.details.ok.accounts_len)
{
/* bogus reply */
GNUNET_break_op (0);
GNUNET_JSON_parse_free (spec);
wr.hr.http_status = 0;
wr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
break;
}
fbm = parse_fees (&master_pub,
fees,
&wr.details.ok.fees_len);
if (NULL == fbm)
{
/* bogus reply */
GNUNET_break_op (0);
GNUNET_JSON_parse_free (spec);
wr.hr.http_status = 0;
wr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
break;
}
/* parse accounts */
{
struct TALER_EXCHANGE_WireAccount was[wr.details.ok.accounts_len];
memset (was,
0,
sizeof (was));
wr.details.ok.accounts = was;
for (unsigned int i = 0;
i<wr.details.ok.accounts_len;
i++)
{
struct TALER_EXCHANGE_WireAccount *wa = &was[i];
json_t *credit_restrictions;
json_t *debit_restrictions;
struct GNUNET_JSON_Specification spec_account[] = {
GNUNET_JSON_spec_string ("payto_uri",
&wa->payto_uri),
GNUNET_JSON_spec_mark_optional (
GNUNET_JSON_spec_string ("conversion_url",
&wa->conversion_url),
NULL),
GNUNET_JSON_spec_json ("credit_restrictions",
&credit_restrictions),
GNUNET_JSON_spec_json ("debit_restrictions",
&debit_restrictions),
GNUNET_JSON_spec_fixed_auto ("master_sig",
&wa->master_sig),
GNUNET_JSON_spec_end ()
};
json_t *account;
account = json_array_get (accounts,
i);
if (GNUNET_OK !=
GNUNET_JSON_parse (account,
spec_account,
NULL, NULL))
{
/* bogus reply */
GNUNET_break_op (0);
wr.hr.http_status = 0;
wr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
break;
}
{
char *err;
err = TALER_payto_validate (wa->payto_uri);
if (NULL != err)
{
GNUNET_break_op (0);
wr.hr.http_status = 0;
wr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
GNUNET_free (err);
break;
}
}
if (GNUNET_OK !=
TALER_exchange_wire_signature_check (wa->payto_uri,
wa->conversion_url,
debit_restrictions,
credit_restrictions,
&master_pub,
&wa->master_sig))
{
/* bogus reply */
GNUNET_break_op (0);
wr.hr.http_status = 0;
wr.hr.ec = TALER_EC_EXCHANGE_WIRE_SIGNATURE_INVALID;
break;
}
if ( (GNUNET_OK !=
parse_restrictions (credit_restrictions,
&wa->credit_restrictions_length,
&wa->credit_restrictions)) ||
(GNUNET_OK !=
parse_restrictions (debit_restrictions,
&wa->debit_restrictions_length,
&wa->debit_restrictions)) )
{
/* bogus reply */
GNUNET_break_op (0);
wr.hr.http_status = 0;
wr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
break;
}
GNUNET_JSON_parse_free (spec_account);
} /* end 'for all accounts */
if ( (0 != wr.hr.http_status) &&
(NULL != wh->cb) )
{
wh->cb (wh->cb_cls,
&wr);
wh->cb = NULL;
}
free_accounts (was,
wr.details.ok.accounts_len);
} /* end of 'parse accounts */
free_fees (fbm,
wr.details.ok.fees_len);
GNUNET_JSON_parse_free (spec);
} /* end of MHD_HTTP_OK */
break;
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 */
wr.hr.ec = TALER_JSON_get_error_code (j);
wr.hr.hint = TALER_JSON_get_error_hint (j);
break;
case MHD_HTTP_NOT_FOUND:
/* Nothing really to verify, this should never
happen, we should pass the JSON reply to the application */
wr.hr.ec = TALER_JSON_get_error_code (j);
wr.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 */
wr.hr.ec = TALER_JSON_get_error_code (j);
wr.hr.hint = TALER_JSON_get_error_hint (j);
break;
default:
/* unexpected response code */
if (MHD_HTTP_GATEWAY_TIMEOUT == response_code)
wh->exchange->wire_error_count++;
GNUNET_break_op (0);
wr.hr.ec = TALER_JSON_get_error_code (j);
wr.hr.hint = TALER_JSON_get_error_hint (j);
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Unexpected response code %u/%d for exchange wire\n",
(unsigned int) response_code,
(int) wr.hr.ec);
break;
}
if (NULL != wh->cb)
wh->cb (wh->cb_cls,
&wr);
TALER_EXCHANGE_wire_cancel (wh);
}
/**
* Compute the network timeout for the next request to /wire.
*
* @param exchange the exchange handle
* @returns the timeout in seconds (for use by CURL)
*/
static long
get_wire_timeout_seconds (struct TALER_EXCHANGE_Handle *exchange)
{
return GNUNET_MIN (60,
5 + (1L << exchange->wire_error_count));
}
/**
* Obtain information about a exchange's wire instructions.
* A exchange may provide wire instructions for creating
* a reserve. The wire instructions also indicate
* which wire formats merchants may use with the exchange.
* This API is typically used by a wallet for wiring
* funds, and possibly by a merchant to determine
* supported wire formats.
*
* Note that while we return the (main) response verbatim to the
* caller for further processing, we do already verify that the
* response is well-formed (i.e. that signatures included in the
* response are all valid). If the exchange's reply is not well-formed,
* we return an HTTP status code of zero to @a cb.
*
* @param exchange the exchange handle; the exchange must be ready to operate
* @param wire_cb the callback to call when a reply for this request is available
* @param wire_cb_cls closure for the above callback
* @return a handle for this request
*/
struct TALER_EXCHANGE_WireHandle *
TALER_EXCHANGE_wire (struct TALER_EXCHANGE_Handle *exchange,
TALER_EXCHANGE_WireCallback wire_cb,
void *wire_cb_cls)
{
struct TALER_EXCHANGE_WireHandle *wh;
struct GNUNET_CURL_Context *ctx;
CURL *eh;
if (GNUNET_YES !=
TEAH_handle_is_ready (exchange))
{
GNUNET_break (0);
return NULL;
}
wh = GNUNET_new (struct TALER_EXCHANGE_WireHandle);
wh->exchange = exchange;
wh->cb = wire_cb;
wh->cb_cls = wire_cb_cls;
wh->url = TEAH_path_to_url (exchange,
"/wire");
if (NULL == wh->url)
{
GNUNET_free (wh);
return NULL;
}
eh = TALER_EXCHANGE_curl_easy_get_ (wh->url);
if (NULL == eh)
{
GNUNET_break (0);
GNUNET_free (wh->url);
GNUNET_free (wh);
return NULL;
}
GNUNET_break (CURLE_OK ==
curl_easy_setopt (eh,
CURLOPT_TIMEOUT,
get_wire_timeout_seconds (wh->exchange)));
ctx = TEAH_handle_to_context (exchange);
wh->job = GNUNET_CURL_job_add_with_ct_json (ctx,
eh,
&handle_wire_finished,
wh);
return wh;
}
/**
* Cancel a wire information request. This function cannot be used
* on a request handle if a response is already served for it.
*
* @param wh the wire information request handle
*/
void
TALER_EXCHANGE_wire_cancel (struct TALER_EXCHANGE_WireHandle *wh)
{
if (NULL != wh->job)
{
GNUNET_CURL_job_cancel (wh->job);
wh->job = NULL;
}
GNUNET_free (wh->url);
GNUNET_free (wh);
}
/* end of exchange_api_wire.c */
|