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-rw-r--r--src/lib/exchange_api_wire.c442
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diff --git a/src/lib/exchange_api_wire.c b/src/lib/exchange_api_wire.c
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+/*
+ This file is part of TALER
+ Copyright (C) 2014-2018 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 exchange-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_wire_lib.h"
+#include "taler_signatures.h"
+#include "taler_wire_plugin.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_WireResultCallback cb;
+
+ /**
+ * Closure for @a cb.
+ */
+ void *cb_cls;
+
+};
+
+
+/**
+ * List of wire fees by method.
+ */
+struct FeeMap
+{
+ /**
+ * Next entry in list.
+ */
+ struct FeeMap *next;
+
+ /**
+ * Wire method this fee structure is for.
+ */
+ char *method;
+
+ /**
+ * Array of wire fees, also linked list, but allocated
+ * only once.
+ */
+ struct TALER_EXCHANGE_WireAggregateFees *fee_list;
+};
+
+
+/**
+ * Frees @a fm.
+ *
+ * @param fm memory to release
+ */
+static void
+free_fees (struct FeeMap *fm)
+{
+ while (NULL != fm)
+ {
+ struct FeeMap *fe = fm->next;
+
+ GNUNET_free (fm->fee_list);
+ GNUNET_free (fm->method);
+ GNUNET_free (fm);
+ fm = fe;
+ }
+}
+
+
+/**
+ * Parse wire @a fees and return map.
+ *
+ * @param fees json AggregateTransferFee to parse
+ * @return NULL on error
+ */
+static struct FeeMap *
+parse_fees (json_t *fees)
+{
+ struct FeeMap *fm = NULL;
+ const char *key;
+ json_t *fee_array;
+
+ json_object_foreach (fees, key, fee_array) {
+ struct FeeMap *fe = GNUNET_new (struct FeeMap);
+ int len;
+ unsigned int idx;
+ json_t *fee;
+
+ if (0 == (len = json_array_size (fee_array)))
+ {
+ GNUNET_break_op (0);
+ GNUNET_free (fe);
+ continue; /* skip */
+ }
+ fe->method = GNUNET_strdup (key);
+ fe->next = fm;
+ fe->fee_list = GNUNET_new_array (len,
+ struct TALER_EXCHANGE_WireAggregateFees);
+ fm = fe;
+ json_array_foreach (fee_array, idx, fee)
+ {
+ struct TALER_EXCHANGE_WireAggregateFees *wa = &fe->fee_list[idx];
+ struct GNUNET_JSON_Specification spec[] = {
+ GNUNET_JSON_spec_fixed_auto ("sig",
+ &wa->master_sig),
+ TALER_JSON_spec_amount ("wire_fee",
+ &wa->wire_fee),
+ TALER_JSON_spec_amount ("closing_fee",
+ &wa->closing_fee),
+ GNUNET_JSON_spec_absolute_time ("start_date",
+ &wa->start_date),
+ GNUNET_JSON_spec_absolute_time ("end_date",
+ &wa->end_date),
+ GNUNET_JSON_spec_end()
+ };
+
+ if (GNUNET_OK !=
+ GNUNET_JSON_parse (fee,
+ spec,
+ NULL,
+ NULL))
+ {
+ GNUNET_break_op (0);
+ free_fees (fm);
+ return NULL;
+ }
+ if (idx + 1 < len)
+ wa->next = &fe->fee_list[idx + 1];
+ else
+ wa->next = NULL;
+ }
+ }
+ return fm;
+}
+
+
+/**
+ * Find fee by @a method.
+ *
+ * @param fm map to look in
+ * @param method key to look for
+ * @return NULL if fee is not specified in @a fm
+ */
+static const struct TALER_EXCHANGE_WireAggregateFees *
+lookup_fee (const struct FeeMap *fm,
+ const char *method)
+{
+ for (;NULL != fm; fm = fm->next)
+ if (0 == strcasecmp (fm->method,
+ method))
+ return fm->fee_list;
+ return NULL;
+}
+
+
+/**
+ * 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;
+ enum TALER_ErrorCode ec;
+ const json_t *j = response;
+
+ TALER_LOG_DEBUG ("Checking raw /wire response\n");
+ wh->job = NULL;
+ ec = TALER_EC_NONE;
+ switch (response_code)
+ {
+ case 0:
+ break;
+ case MHD_HTTP_OK:
+ {
+ json_t *accounts;
+ json_t *fees;
+ int num_accounts;
+ struct FeeMap *fm;
+ const struct TALER_EXCHANGE_Keys *key_state;
+ struct GNUNET_JSON_Specification spec[] = {
+ GNUNET_JSON_spec_json ("accounts", &accounts),
+ GNUNET_JSON_spec_json ("fees", &fees),
+ GNUNET_JSON_spec_end()
+ };
+
+ if (GNUNET_OK !=
+ GNUNET_JSON_parse (j,
+ spec,
+ NULL, NULL))
+ {
+ /* bogus reply */
+ GNUNET_break_op (0);
+ response_code = 0;
+ ec = TALER_EC_SERVER_JSON_INVALID;
+ break;
+ }
+ if (0 == (num_accounts = json_array_size (accounts)))
+ {
+ /* bogus reply */
+ GNUNET_break_op (0);
+ GNUNET_JSON_parse_free (spec);
+ response_code = 0;
+ ec = TALER_EC_SERVER_JSON_INVALID;
+ break;
+ }
+ if (NULL == (fm = parse_fees (fees)))
+ {
+ /* bogus reply */
+ GNUNET_break_op (0);
+ GNUNET_JSON_parse_free (spec);
+ response_code = 0;
+ ec = TALER_EC_SERVER_JSON_INVALID;
+ break;
+ }
+
+ key_state = TALER_EXCHANGE_get_keys (wh->exchange);
+ /* parse accounts */
+ {
+ struct TALER_EXCHANGE_WireAccount was[num_accounts];
+
+ for (unsigned int i=0;i<num_accounts;i++)
+ {
+ struct TALER_EXCHANGE_WireAccount *wa = &was[i];
+ json_t *account;
+ struct GNUNET_JSON_Specification spec_account[] = {
+ GNUNET_JSON_spec_string ("url", &wa->url),
+ GNUNET_JSON_spec_fixed_auto ("master_sig", &wa->master_sig),
+ GNUNET_JSON_spec_end()
+ };
+ char *method;
+
+ account = json_array_get (accounts,
+ i);
+ if (GNUNET_OK !=
+ TALER_JSON_exchange_wire_signature_check (account,
+ &key_state->master_pub))
+ {
+ /* bogus reply */
+ GNUNET_break_op (0);
+ response_code = 0;
+ ec = TALER_EC_SERVER_SIGNATURE_INVALID;
+ break;
+ }
+ if (GNUNET_OK !=
+ GNUNET_JSON_parse (account,
+ spec_account,
+ NULL, NULL))
+ {
+ /* bogus reply */
+ GNUNET_break_op (0);
+ response_code = 0;
+ ec = TALER_EC_SERVER_JSON_INVALID;
+ break;
+ }
+ if (NULL == (method = TALER_WIRE_payto_get_method (wa->url)))
+ {
+ /* bogus reply */
+ GNUNET_break_op (0);
+ response_code = 0;
+ ec = TALER_EC_SERVER_JSON_INVALID;
+ break;
+ }
+ if (NULL == (wa->fees = lookup_fee (fm,
+ method)))
+ {
+ /* bogus reply */
+ GNUNET_break_op (0);
+ response_code = 0;
+ ec = TALER_EC_SERVER_JSON_INVALID;
+ GNUNET_free (method);
+ break;
+ }
+ GNUNET_free (method);
+ } /* end 'for all accounts */
+ if ( (0 != response_code) &&
+ (NULL != wh->cb) )
+ {
+ wh->cb (wh->cb_cls,
+ response_code,
+ TALER_EC_NONE,
+ num_accounts,
+ was);
+ wh->cb = NULL;
+ }
+ } /* end of 'parse accounts */
+ free_fees (fm);
+ 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 */
+ break;
+ case MHD_HTTP_NOT_FOUND:
+ /* Nothing really to verify, this should never
+ happen, we should pass the JSON reply to the application */
+ break;
+ case MHD_HTTP_INTERNAL_SERVER_ERROR:
+ /* Server had an internal issue; we should retry, but this API
+ leaves this to the application */
+ break;
+ default:
+ /* unexpected response code */
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ "Unexpected response code %u\n",
+ (unsigned int) response_code);
+ GNUNET_break (0);
+ response_code = 0;
+ break;
+ }
+ if (NULL != wh->cb)
+ wh->cb (wh->cb_cls,
+ response_code,
+ (0 == response_code) ? ec : TALER_JSON_get_error_code (j),
+ 0,
+ NULL);
+ TALER_EXCHANGE_wire_cancel (wh);
+}
+
+
+/**
+ * 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_WireResultCallback 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");
+
+ eh = TEL_curl_easy_get (wh->url);
+ ctx = TEAH_handle_to_context (exchange);
+ wh->job = GNUNET_CURL_job_add (ctx,
+ eh,
+ GNUNET_YES,
+ &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 */