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authorChristian Grothoff <christian@grothoff.org>2019-01-11 21:27:34 +0100
committerChristian Grothoff <christian@grothoff.org>2019-01-11 21:43:15 +0100
commit54fc83ee6b910d482948c6ec8185df7aab1b0cb1 (patch)
tree10c04cad1392659a9ccef469271f866e393ebb48 /src/lib/exchange_api_reserve.c
parent57ab9f9fdba607fcc3817adf58f37c5390f8d220 (diff)
downloadexchange-54fc83ee6b910d482948c6ec8185df7aab1b0cb1.tar.gz
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fix cyclic dependency by combining exchange-lib and auditor-lib directories
Diffstat (limited to 'src/lib/exchange_api_reserve.c')
-rw-r--r--src/lib/exchange_api_reserve.c1203
1 files changed, 1203 insertions, 0 deletions
diff --git a/src/lib/exchange_api_reserve.c b/src/lib/exchange_api_reserve.c
new file mode 100644
index 00000000..d4d0cb9a
--- /dev/null
+++ b/src/lib/exchange_api_reserve.c
@@ -0,0 +1,1203 @@
+/*
+ This file is part of TALER
+ Copyright (C) 2014, 2015 GNUnet e.V.
+
+ 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_reserve.c
+ * @brief Implementation of the /reserve requests 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_json_lib.h>
+#include <gnunet/gnunet_curl_lib.h>
+#include "taler_exchange_service.h"
+#include "taler_json_lib.h"
+#include "exchange_api_handle.h"
+#include "taler_signatures.h"
+#include "exchange_api_curl_defaults.h"
+
+
+/* ********************** /reserve/status ********************** */
+
+/**
+ * @brief A Withdraw Status Handle
+ */
+struct TALER_EXCHANGE_ReserveStatusHandle
+{
+
+ /**
+ * 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_ReserveStatusResultCallback cb;
+
+ /**
+ * Public key of the reserve we are querying.
+ */
+ struct TALER_ReservePublicKeyP reserve_pub;
+
+ /**
+ * Closure for @a cb.
+ */
+ void *cb_cls;
+
+};
+
+
+/**
+ * Parse history given in JSON format and return it in binary
+ * format.
+ *
+ * @param exchange connection to the exchange we can use
+ * @param history JSON array with the history
+ * @param reserve_pub public key of the reserve to inspect
+ * @param currency currency we expect the balance to be in
+ * @param[out] balance final balance
+ * @param history_length number of entries in @a history
+ * @param[out] rhistory array of length @a history_length, set to the
+ * parsed history entries
+ * @return #GNUNET_OK if history was valid and @a rhistory and @a balance
+ * were set,
+ * #GNUNET_SYSERR if there was a protocol violation in @a history
+ */
+static int
+parse_reserve_history (struct TALER_EXCHANGE_Handle *exchange,
+ const json_t *history,
+ const struct TALER_ReservePublicKeyP *reserve_pub,
+ const char *currency,
+ struct TALER_Amount *balance,
+ unsigned int history_length,
+ struct TALER_EXCHANGE_ReserveHistory *rhistory)
+{
+ struct GNUNET_HashCode uuid[history_length];
+ unsigned int uuid_off;
+ struct TALER_Amount total_in;
+ struct TALER_Amount total_out;
+ size_t off;
+
+ GNUNET_assert (GNUNET_OK ==
+ TALER_amount_get_zero (currency,
+ &total_in));
+ GNUNET_assert (GNUNET_OK ==
+ TALER_amount_get_zero (currency,
+ &total_out));
+ uuid_off = 0;
+ for (off=0;off<history_length;off++)
+ {
+ json_t *transaction;
+ struct TALER_Amount amount;
+ const char *type;
+ struct GNUNET_JSON_Specification hist_spec[] = {
+ GNUNET_JSON_spec_string ("type", &type),
+ TALER_JSON_spec_amount ("amount",
+ &amount),
+ /* 'wire' and 'signature' are optional depending on 'type'! */
+ GNUNET_JSON_spec_end()
+ };
+
+ transaction = json_array_get (history,
+ off);
+ if (GNUNET_OK !=
+ GNUNET_JSON_parse (transaction,
+ hist_spec,
+ NULL, NULL))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ rhistory[off].amount = amount;
+
+ if (0 == strcasecmp (type,
+ "DEPOSIT"))
+ {
+ const char *wire_url;
+ void *wire_reference;
+ size_t wire_reference_size;
+ struct GNUNET_TIME_Absolute timestamp;
+
+ struct GNUNET_JSON_Specification withdraw_spec[] = {
+ GNUNET_JSON_spec_varsize ("wire_reference",
+ &wire_reference,
+ &wire_reference_size),
+ GNUNET_JSON_spec_absolute_time ("timestamp",
+ &timestamp),
+ GNUNET_JSON_spec_string ("sender_account_url",
+ &wire_url),
+ GNUNET_JSON_spec_end()
+ };
+
+ rhistory[off].type = TALER_EXCHANGE_RTT_DEPOSIT;
+ if (GNUNET_OK !=
+ TALER_amount_add (&total_in,
+ &total_in,
+ &amount))
+ {
+ /* overflow in history already!? inconceivable! Bad exchange! */
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (GNUNET_OK !=
+ GNUNET_JSON_parse (transaction,
+ withdraw_spec,
+ NULL, NULL))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ rhistory[off].details.in_details.sender_url = GNUNET_strdup (wire_url);
+ rhistory[off].details.in_details.wire_reference = wire_reference;
+ rhistory[off].details.in_details.wire_reference_size = wire_reference_size;
+ rhistory[off].details.in_details.timestamp = timestamp;
+ /* end type==DEPOSIT */
+ }
+ else if (0 == strcasecmp (type,
+ "WITHDRAW"))
+ {
+ struct TALER_ReserveSignatureP sig;
+ struct TALER_WithdrawRequestPS withdraw_purpose;
+ struct GNUNET_JSON_Specification withdraw_spec[] = {
+ GNUNET_JSON_spec_fixed_auto ("reserve_sig",
+ &sig),
+ TALER_JSON_spec_amount_nbo ("withdraw_fee",
+ &withdraw_purpose.withdraw_fee),
+ GNUNET_JSON_spec_fixed_auto ("h_denom_pub",
+ &withdraw_purpose.h_denomination_pub),
+ GNUNET_JSON_spec_fixed_auto ("h_coin_envelope",
+ &withdraw_purpose.h_coin_envelope),
+ GNUNET_JSON_spec_end()
+ };
+ unsigned int i;
+
+ rhistory[off].type = TALER_EXCHANGE_RTT_WITHDRAWAL;
+ if (GNUNET_OK !=
+ GNUNET_JSON_parse (transaction,
+ withdraw_spec,
+ NULL, NULL))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ withdraw_purpose.purpose.size
+ = htonl (sizeof (withdraw_purpose));
+ withdraw_purpose.purpose.purpose
+ = htonl (TALER_SIGNATURE_WALLET_RESERVE_WITHDRAW);
+ withdraw_purpose.reserve_pub = *reserve_pub;
+ TALER_amount_hton (&withdraw_purpose.amount_with_fee,
+ &amount);
+ /* Check that the signature is a valid withdraw request */
+ if (GNUNET_OK !=
+ GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_WALLET_RESERVE_WITHDRAW,
+ &withdraw_purpose.purpose,
+ &sig.eddsa_signature,
+ &reserve_pub->eddsa_pub))
+ {
+ GNUNET_break_op (0);
+ GNUNET_JSON_parse_free (withdraw_spec);
+ return GNUNET_SYSERR;
+ }
+ /* TODO: check that withdraw fee matches expectations! */
+ rhistory[off].details.out_authorization_sig
+ = json_object_get (transaction,
+ "signature");
+ /* Check check that the same withdraw transaction
+ isn't listed twice by the exchange. We use the
+ "uuid" array to remember the hashes of all
+ purposes, and compare the hashes to find
+ duplicates. */
+ GNUNET_CRYPTO_hash (&withdraw_purpose,
+ ntohl (withdraw_purpose.purpose.size),
+ &uuid[uuid_off]);
+ for (i=0;i<uuid_off;i++)
+ {
+ if (0 == memcmp (&uuid[uuid_off],
+ &uuid[i],
+ sizeof (struct GNUNET_HashCode)))
+ {
+ GNUNET_break_op (0);
+ GNUNET_JSON_parse_free (withdraw_spec);
+ return GNUNET_SYSERR;
+ }
+ }
+ uuid_off++;
+
+ if (GNUNET_OK !=
+ TALER_amount_add (&total_out,
+ &total_out,
+ &amount))
+ {
+ /* overflow in history already!? inconceivable! Bad exchange! */
+ GNUNET_break_op (0);
+ GNUNET_JSON_parse_free (withdraw_spec);
+ return GNUNET_SYSERR;
+ }
+ /* end type==WITHDRAW */
+ }
+ else if (0 == strcasecmp (type,
+ "PAYBACK"))
+ {
+ struct TALER_PaybackConfirmationPS pc;
+ struct GNUNET_TIME_Absolute timestamp;
+ const struct TALER_EXCHANGE_Keys *key_state;
+ struct GNUNET_JSON_Specification payback_spec[] = {
+ GNUNET_JSON_spec_fixed_auto ("coin_pub",
+ &pc.coin_pub),
+ GNUNET_JSON_spec_fixed_auto ("exchange_sig",
+ &rhistory[off].details.payback_details.exchange_sig),
+ GNUNET_JSON_spec_fixed_auto ("exchange_pub",
+ &rhistory[off].details.payback_details.exchange_pub),
+ GNUNET_JSON_spec_absolute_time_nbo ("timestamp",
+ &pc.timestamp),
+ GNUNET_JSON_spec_end()
+ };
+
+ rhistory[off].type = TALER_EXCHANGE_RTT_PAYBACK;
+ rhistory[off].amount = amount;
+ if (GNUNET_OK !=
+ GNUNET_JSON_parse (transaction,
+ payback_spec,
+ NULL, NULL))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ rhistory[off].details.payback_details.coin_pub = pc.coin_pub;
+ TALER_amount_hton (&pc.payback_amount,
+ &amount);
+ pc.purpose.size = htonl (sizeof (pc));
+ pc.purpose.purpose = htonl (TALER_SIGNATURE_EXCHANGE_CONFIRM_PAYBACK);
+ pc.reserve_pub = *reserve_pub;
+ timestamp = GNUNET_TIME_absolute_ntoh (pc.timestamp);
+ rhistory[off].details.payback_details.timestamp = timestamp;
+
+ key_state = TALER_EXCHANGE_get_keys (exchange);
+ if (GNUNET_OK !=
+ TALER_EXCHANGE_test_signing_key (key_state,
+ &rhistory[off].details.payback_details.exchange_pub))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (GNUNET_OK !=
+ GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_EXCHANGE_CONFIRM_PAYBACK,
+ &pc.purpose,
+ &rhistory[off].details.payback_details.exchange_sig.eddsa_signature,
+ &rhistory[off].details.payback_details.exchange_pub.eddsa_pub))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (GNUNET_OK !=
+ TALER_amount_add (&total_in,
+ &total_in,
+ &rhistory[off].amount))
+ {
+ /* overflow in history already!? inconceivable! Bad exchange! */
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ /* end type==PAYBACK */
+ }
+ else if (0 == strcasecmp (type,
+ "CLOSING"))
+ {
+ const struct TALER_EXCHANGE_Keys *key_state;
+ struct TALER_ReserveCloseConfirmationPS rcc;
+ struct GNUNET_TIME_Absolute timestamp;
+ struct GNUNET_JSON_Specification closing_spec[] = {
+ GNUNET_JSON_spec_string ("receiver_account_details",
+ &rhistory[off].details.close_details.receiver_account_details),
+ GNUNET_JSON_spec_fixed_auto ("wtid",
+ &rhistory[off].details.close_details.wtid),
+ GNUNET_JSON_spec_fixed_auto ("exchange_sig",
+ &rhistory[off].details.close_details.exchange_sig),
+ GNUNET_JSON_spec_fixed_auto ("exchange_pub",
+ &rhistory[off].details.close_details.exchange_pub),
+ TALER_JSON_spec_amount_nbo ("closing_fee",
+ &rcc.closing_fee),
+ GNUNET_JSON_spec_absolute_time_nbo ("timestamp",
+ &rcc.timestamp),
+ GNUNET_JSON_spec_end()
+ };
+
+ rhistory[off].type = TALER_EXCHANGE_RTT_CLOSE;
+ rhistory[off].amount = amount;
+ if (GNUNET_OK !=
+ GNUNET_JSON_parse (transaction,
+ closing_spec,
+ NULL, NULL))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ TALER_amount_hton (&rcc.closing_amount,
+ &amount);
+ GNUNET_CRYPTO_hash (rhistory[off].details.close_details.receiver_account_details,
+ strlen (rhistory[off].details.close_details.receiver_account_details) + 1,
+ &rcc.h_wire);
+ rcc.wtid = rhistory[off].details.close_details.wtid;
+ rcc.purpose.size = htonl (sizeof (rcc));
+ rcc.purpose.purpose = htonl (TALER_SIGNATURE_EXCHANGE_RESERVE_CLOSED);
+ rcc.reserve_pub = *reserve_pub;
+ timestamp = GNUNET_TIME_absolute_ntoh (rcc.timestamp);
+ rhistory[off].details.close_details.timestamp = timestamp;
+
+ key_state = TALER_EXCHANGE_get_keys (exchange);
+ if (GNUNET_OK !=
+ TALER_EXCHANGE_test_signing_key (key_state,
+ &rhistory[off].details.close_details.exchange_pub))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (GNUNET_OK !=
+ GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_EXCHANGE_RESERVE_CLOSED,
+ &rcc.purpose,
+ &rhistory[off].details.close_details.exchange_sig.eddsa_signature,
+ &rhistory[off].details.close_details.exchange_pub.eddsa_pub))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (GNUNET_OK !=
+ TALER_amount_add (&total_out,
+ &total_out,
+ &rhistory[off].amount))
+ {
+ /* overflow in history already!? inconceivable! Bad exchange! */
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ /* end type==CLOSING */
+ }
+ else
+ {
+ /* unexpected 'type', protocol incompatibility, complain! */
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ }
+
+ /* check balance = total_in - total_out < withdraw-amount */
+ if (GNUNET_SYSERR ==
+ TALER_amount_subtract (balance,
+ &total_in,
+ &total_out))
+ {
+ /* total_in < total_out, why did the exchange ever allow this!? */
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ return GNUNET_OK;
+}
+
+
+/**
+ * Free memory (potentially) allocated by #parse_reserve_history().
+ *
+ * @param rhistory result to free
+ * @param len number of entries in @a rhistory
+ */
+static void
+free_rhistory (struct TALER_EXCHANGE_ReserveHistory *rhistory,
+ unsigned int len)
+{
+ for (unsigned int i=0;i<len;i++)
+ {
+ switch (rhistory[i].type)
+ {
+ case TALER_EXCHANGE_RTT_DEPOSIT:
+ GNUNET_free_non_null (rhistory[i].details.in_details.wire_reference);
+ GNUNET_free_non_null (rhistory[i].details.in_details.sender_url);
+ break;
+ case TALER_EXCHANGE_RTT_WITHDRAWAL:
+ break;
+ case TALER_EXCHANGE_RTT_PAYBACK:
+ break;
+ case TALER_EXCHANGE_RTT_CLOSE:
+ // should we free "receiver_account_details" ?
+ break;
+ }
+ }
+}
+
+
+/**
+ * Function called when we're done processing the
+ * HTTP /reserve/status request.
+ *
+ * @param cls the `struct TALER_EXCHANGE_ReserveStatusHandle`
+ * @param response_code HTTP response code, 0 on error
+ * @param response parsed JSON result, NULL on error
+ */
+static void
+handle_reserve_status_finished (void *cls,
+ long response_code,
+ const void *response)
+{
+ struct TALER_EXCHANGE_ReserveStatusHandle *rsh = cls;
+ const json_t *j = response;
+
+ rsh->job = NULL;
+ switch (response_code)
+ {
+ case 0:
+ break;
+ case MHD_HTTP_OK:
+ {
+ /* TODO: move into separate function... */
+ json_t *history;
+ unsigned int len;
+ struct TALER_Amount balance;
+ struct TALER_Amount balance_from_history;
+ struct GNUNET_JSON_Specification spec[] = {
+ TALER_JSON_spec_amount ("balance", &balance),
+ GNUNET_JSON_spec_end()
+ };
+
+ if (GNUNET_OK !=
+ GNUNET_JSON_parse (j,
+ spec,
+ NULL,
+ NULL))
+ {
+ GNUNET_break_op (0);
+ response_code = 0;
+ break;
+ }
+ history = json_object_get (j,
+ "history");
+ if (NULL == history)
+ {
+ GNUNET_break_op (0);
+ response_code = 0;
+ break;
+ }
+ len = json_array_size (history);
+ {
+ struct TALER_EXCHANGE_ReserveHistory rhistory[len];
+
+ memset (rhistory, 0, sizeof (rhistory));
+ if (GNUNET_OK !=
+ parse_reserve_history (rsh->exchange,
+ history,
+ &rsh->reserve_pub,
+ balance.currency,
+ &balance_from_history,
+ len,
+ rhistory))
+ {
+ GNUNET_break_op (0);
+ response_code = 0;
+ }
+ if ( (0 != response_code) &&
+ (0 !=
+ TALER_amount_cmp (&balance_from_history,
+ &balance)) )
+ {
+ /* exchange cannot add up balances!? */
+ GNUNET_break_op (0);
+ response_code = 0;
+ }
+ if (0 != response_code)
+ {
+ rsh->cb (rsh->cb_cls,
+ response_code,
+ TALER_EC_NONE,
+ j,
+ &balance,
+ len,
+ rhistory);
+ rsh->cb = NULL;
+ }
+ free_rhistory (rhistory,
+ len);
+ }
+ }
+ 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 != rsh->cb)
+ {
+ rsh->cb (rsh->cb_cls,
+ response_code,
+ TALER_JSON_get_error_code (j),
+ j,
+ NULL,
+ 0, NULL);
+ rsh->cb = NULL;
+ }
+ TALER_EXCHANGE_reserve_status_cancel (rsh);
+}
+
+
+/**
+ * Submit a request to obtain the transaction history of a reserve
+ * from the exchange. Note that while we return the full response 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 and add up to the balance). 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 reserve_pub public key of the reserve to inspect
+ * @param cb the callback to call when a reply for this request is available
+ * @param cb_cls closure for the above callback
+ * @return a handle for this request; NULL if the inputs are invalid (i.e.
+ * signatures fail to verify). In this case, the callback is not called.
+ */
+struct TALER_EXCHANGE_ReserveStatusHandle *
+TALER_EXCHANGE_reserve_status (struct TALER_EXCHANGE_Handle *exchange,
+ const struct TALER_ReservePublicKeyP *reserve_pub,
+ TALER_EXCHANGE_ReserveStatusResultCallback cb,
+ void *cb_cls)
+{
+ struct TALER_EXCHANGE_ReserveStatusHandle *rsh;
+ struct GNUNET_CURL_Context *ctx;
+ CURL *eh;
+ char *pub_str;
+ char *arg_str;
+
+ if (GNUNET_YES !=
+ TEAH_handle_is_ready (exchange))
+ {
+ GNUNET_break (0);
+ return NULL;
+ }
+ pub_str = GNUNET_STRINGS_data_to_string_alloc (reserve_pub,
+ sizeof (struct TALER_ReservePublicKeyP));
+ GNUNET_asprintf (&arg_str,
+ "/reserve/status?reserve_pub=%s",
+ pub_str);
+ GNUNET_free (pub_str);
+ rsh = GNUNET_new (struct TALER_EXCHANGE_ReserveStatusHandle);
+ rsh->exchange = exchange;
+ rsh->cb = cb;
+ rsh->cb_cls = cb_cls;
+ rsh->reserve_pub = *reserve_pub;
+ rsh->url = TEAH_path_to_url (exchange,
+ arg_str);
+ GNUNET_free (arg_str);
+
+ eh = TEL_curl_easy_get (rsh->url);
+ ctx = TEAH_handle_to_context (exchange);
+ rsh->job = GNUNET_CURL_job_add (ctx,
+ eh,
+ GNUNET_NO,
+ &handle_reserve_status_finished,
+ rsh);
+ return rsh;
+}
+
+
+/**
+ * Cancel a reserve status request. This function cannot be used
+ * on a request handle if a response is already served for it.
+ *
+ * @param rsh the reserve status request handle
+ */
+void
+TALER_EXCHANGE_reserve_status_cancel (struct TALER_EXCHANGE_ReserveStatusHandle *rsh)
+{
+ if (NULL != rsh->job)
+ {
+ GNUNET_CURL_job_cancel (rsh->job);
+ rsh->job = NULL;
+ }
+ GNUNET_free (rsh->url);
+ GNUNET_free (rsh);
+}
+
+
+/* ********************** /reserve/withdraw ********************** */
+
+/**
+ * @brief A Withdraw Sign Handle
+ */
+struct TALER_EXCHANGE_ReserveWithdrawHandle
+{
+
+ /**
+ * The connection to exchange this request handle will use
+ */
+ struct TALER_EXCHANGE_Handle *exchange;
+
+ /**
+ * The url for this request.
+ */
+ char *url;
+
+ /**
+ * JSON encoding of the request to POST.
+ */
+ char *json_enc;
+
+ /**
+ * Handle for the request.
+ */
+ struct GNUNET_CURL_Job *job;
+
+ /**
+ * Function to call with the result.
+ */
+ TALER_EXCHANGE_ReserveWithdrawResultCallback cb;
+
+ /**
+ * Secrets of the planchet.
+ */
+ struct TALER_PlanchetSecretsP ps;
+
+ /**
+ * Denomination key we are withdrawing.
+ */
+ const struct TALER_EXCHANGE_DenomPublicKey *pk;
+
+ /**
+ * Closure for @a cb.
+ */
+ void *cb_cls;
+
+ /**
+ * Hash of the public key of the coin we are signing.
+ */
+ struct GNUNET_HashCode c_hash;
+
+ /**
+ * Public key of the reserve we are withdrawing from.
+ */
+ struct TALER_ReservePublicKeyP reserve_pub;
+
+};
+
+
+/**
+ * We got a 200 OK response for the /reserve/withdraw operation.
+ * Extract the coin's signature and return it to the caller.
+ * The signature we get from the exchange is for the blinded value.
+ * Thus, we first must unblind it and then should verify its
+ * validity against our coin's hash.
+ *
+ * If everything checks out, we return the unblinded signature
+ * to the application via the callback.
+ *
+ * @param wsh operation handle
+ * @param json reply from the exchange
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on errors
+ */
+static int
+reserve_withdraw_ok (struct TALER_EXCHANGE_ReserveWithdrawHandle *wsh,
+ const json_t *json)
+{
+ struct GNUNET_CRYPTO_RsaSignature *blind_sig;
+ struct TALER_FreshCoin fc;
+ struct GNUNET_JSON_Specification spec[] = {
+ GNUNET_JSON_spec_rsa_signature ("ev_sig",
+ &blind_sig),
+ GNUNET_JSON_spec_end()
+ };
+
+ if (GNUNET_OK !=
+ GNUNET_JSON_parse (json,
+ spec,
+ NULL, NULL))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (GNUNET_OK !=
+ TALER_planchet_to_coin (&wsh->pk->key,
+ blind_sig,
+ &wsh->ps,
+ &wsh->c_hash,
+ &fc))
+ {
+ GNUNET_break_op (0);
+ GNUNET_JSON_parse_free (spec);
+ return GNUNET_SYSERR;
+ }
+ GNUNET_JSON_parse_free (spec);
+
+ /* signature is valid, return it to the application */
+ wsh->cb (wsh->cb_cls,
+ MHD_HTTP_OK,
+ TALER_EC_NONE,
+ &fc.sig,
+ json);
+ /* make sure callback isn't called again after return */
+ wsh->cb = NULL;
+ GNUNET_CRYPTO_rsa_signature_free (fc.sig.rsa_signature);
+ return GNUNET_OK;
+}
+
+
+/**
+ * We got a 403 FORBIDDEN response for the /reserve/withdraw operation.
+ * Check the signatures on the withdraw transactions in the provided
+ * history and that the balances add up. We don't do anything directly
+ * with the information, as the JSON will be returned to the application.
+ * However, our job is ensuring that the exchange followed the protocol, and
+ * this in particular means checking all of the signatures in the history.
+ *
+ * @param wsh operation handle
+ * @param json reply from the exchange
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on errors
+ */
+static int
+reserve_withdraw_payment_required (struct TALER_EXCHANGE_ReserveWithdrawHandle *wsh,
+ const json_t *json)
+{
+ struct TALER_Amount balance;
+ struct TALER_Amount balance_from_history;
+ struct TALER_Amount requested_amount;
+ json_t *history;
+ size_t len;
+ struct GNUNET_JSON_Specification spec[] = {
+ TALER_JSON_spec_amount ("balance", &balance),
+ GNUNET_JSON_spec_end()
+ };
+
+ if (GNUNET_OK !=
+ GNUNET_JSON_parse (json,
+ spec,
+ NULL, NULL))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ history = json_object_get (json,
+ "history");
+ if (NULL == history)
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+
+ /* go over transaction history and compute
+ total incoming and outgoing amounts */
+ len = json_array_size (history);
+ {
+ struct TALER_EXCHANGE_ReserveHistory *rhistory;
+
+ /* Use heap allocation as "len" may be very big and thus this may
+ not fit on the stack. Use "GNUNET_malloc_large" as a malicious
+ exchange may theoretically try to crash us by giving a history
+ that does not fit into our memory. */
+ rhistory = GNUNET_malloc_large (sizeof (struct TALER_EXCHANGE_ReserveHistory) * len);
+ if (NULL == rhistory)
+ {
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
+ }
+
+ if (GNUNET_OK !=
+ parse_reserve_history (wsh->exchange,
+ history,
+ &wsh->reserve_pub,
+ balance.currency,
+ &balance_from_history,
+ len,
+ rhistory))
+ {
+ GNUNET_break_op (0);
+ free_rhistory (rhistory,
+ len);
+ return GNUNET_SYSERR;
+ }
+ free_rhistory (rhistory,
+ len);
+ }
+
+ if (0 !=
+ TALER_amount_cmp (&balance_from_history,
+ &balance))
+ {
+ /* exchange cannot add up balances!? */
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ /* Compute how much we expected to charge to the reserve */
+ if (GNUNET_OK !=
+ TALER_amount_add (&requested_amount,
+ &wsh->pk->value,
+ &wsh->pk->fee_withdraw))
+ {
+ /* Overflow here? Very strange, our CPU must be fried... */
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
+ }
+ /* Check that funds were really insufficient */
+ if (0 >= TALER_amount_cmp (&requested_amount,
+ &balance))
+ {
+ /* Requested amount is smaller or equal to reported balance,
+ so this should not have failed. */
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ return GNUNET_OK;
+}
+
+
+/**
+ * Function called when we're done processing the
+ * HTTP /reserve/withdraw request.
+ *
+ * @param cls the `struct TALER_EXCHANGE_ReserveWithdrawHandle`
+ * @param response_code HTTP response code, 0 on error
+ * @param response parsed JSON result, NULL on error
+ */
+static void
+handle_reserve_withdraw_finished (void *cls,
+ long response_code,
+ const void *response)
+{
+ struct TALER_EXCHANGE_ReserveWithdrawHandle *wsh = cls;
+ const json_t *j = response;
+
+ wsh->job = NULL;
+ switch (response_code)
+ {
+ case 0:
+ break;
+ case MHD_HTTP_OK:
+ if (GNUNET_OK !=
+ reserve_withdraw_ok (wsh,
+ j))
+ {
+ GNUNET_break_op (0);
+ response_code = 0;
+ }
+ 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_FORBIDDEN:
+ /* The exchange says that the reserve has insufficient funds;
+ check the signatures in the history... */
+ if (GNUNET_OK !=
+ reserve_withdraw_payment_required (wsh,
+ j))
+ {
+ GNUNET_break_op (0);
+ response_code = 0;
+ }
+ break;
+ case MHD_HTTP_UNAUTHORIZED:
+ GNUNET_break (0);
+ /* Nothing really to verify, exchange says one of the signatures is
+ invalid; as we checked them, this should never happen, we
+ should pass the JSON reply to the application */
+ break;
+ case MHD_HTTP_NOT_FOUND:
+ /* Nothing really to verify, the exchange basically just says
+ that it doesn't know this reserve. Can happen if we
+ query before the wire transfer went through.
+ We should simply 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 != wsh->cb)
+ {
+ wsh->cb (wsh->cb_cls,
+ response_code,
+ TALER_JSON_get_error_code (j),
+ NULL,
+ j);
+ wsh->cb = NULL;
+ }
+ TALER_EXCHANGE_reserve_withdraw_cancel (wsh);
+}
+
+
+/**
+ * Helper function for #TALER_EXCHANGE_reserve_withdraw2() and
+ * #TALER_EXCHANGE_reserve_withdraw().
+ *
+ * @param exchange the exchange handle; the exchange must be ready to operate
+ * @param pk kind of coin to create
+ * @param reserve_sig signature from the reserve authorizing the withdrawal
+ * @param reserve_pub public key of the reserve to withdraw from
+ * @param ps secrets of the planchet
+ * caller must have committed this value to disk before the call (with @a pk)
+ * @param pd planchet details matching @a ps
+ * @param res_cb the callback to call when the final result for this request is available
+ * @param res_cb_cls closure for @a res_cb
+ * @return NULL
+ * if the inputs are invalid (i.e. denomination key not with this exchange).
+ * In this case, the callback is not called.
+ */
+struct TALER_EXCHANGE_ReserveWithdrawHandle *
+reserve_withdraw_internal (struct TALER_EXCHANGE_Handle *exchange,
+ const struct TALER_EXCHANGE_DenomPublicKey *pk,
+ const struct TALER_ReserveSignatureP *reserve_sig,
+ const struct TALER_ReservePublicKeyP *reserve_pub,
+ const struct TALER_PlanchetSecretsP *ps,
+ const struct TALER_PlanchetDetail *pd,
+ TALER_EXCHANGE_ReserveWithdrawResultCallback res_cb,
+ void *res_cb_cls)
+{
+ struct TALER_EXCHANGE_ReserveWithdrawHandle *wsh;
+ struct GNUNET_CURL_Context *ctx;
+ json_t *withdraw_obj;
+ CURL *eh;
+
+ wsh = GNUNET_new (struct TALER_EXCHANGE_ReserveWithdrawHandle);
+ wsh->exchange = exchange;
+ wsh->cb = res_cb;
+ wsh->cb_cls = res_cb_cls;
+ wsh->pk = pk;
+ wsh->reserve_pub = *reserve_pub;
+ wsh->c_hash = pd->c_hash;
+ withdraw_obj = json_pack ("{s:o, s:o," /* denom_pub and coin_ev */
+ " s:o, s:o}",/* reserve_pub and reserve_sig */
+ "denom_pub", GNUNET_JSON_from_rsa_public_key (pk->key.rsa_public_key),
+ "coin_ev", GNUNET_JSON_from_data (pd->coin_ev,
+ pd->coin_ev_size),
+ "reserve_pub", GNUNET_JSON_from_data_auto (reserve_pub),
+ "reserve_sig", GNUNET_JSON_from_data_auto (reserve_sig));
+ if (NULL == withdraw_obj)
+ {
+ GNUNET_break (0);
+ return NULL;
+ }
+
+ wsh->ps = *ps;
+ wsh->url = TEAH_path_to_url (exchange, "/reserve/withdraw");
+
+ eh = TEL_curl_easy_get (wsh->url);
+ GNUNET_assert (NULL != (wsh->json_enc =
+ json_dumps (withdraw_obj,
+ JSON_COMPACT)));
+ json_decref (withdraw_obj);
+ GNUNET_assert (CURLE_OK ==
+ curl_easy_setopt (eh,
+ CURLOPT_POSTFIELDS,
+ wsh->json_enc));
+ GNUNET_assert (CURLE_OK ==
+ curl_easy_setopt (eh,
+ CURLOPT_POSTFIELDSIZE,
+ strlen (wsh->json_enc)));
+ ctx = TEAH_handle_to_context (exchange);
+ wsh->job = GNUNET_CURL_job_add (ctx,
+ eh,
+ GNUNET_YES,
+ &handle_reserve_withdraw_finished,
+ wsh);
+ return wsh;
+}
+
+
+/**
+ * Withdraw a coin from the exchange using a /reserve/withdraw request. Note
+ * that to ensure that no money is lost in case of hardware failures,
+ * the caller must have committed (most of) the arguments to disk
+ * before calling, and be ready to repeat the request with the same
+ * arguments in case of failures.
+ *
+ * @param exchange the exchange handle; the exchange must be ready to operate
+ * @param pk kind of coin to create
+ * @param reserve_priv private key of the reserve to withdraw from
+ * @param ps secrets of the planchet
+ * caller must have committed this value to disk before the call (with @a pk)
+ * @param res_cb the callback to call when the final result for this request is available
+ * @param res_cb_cls closure for the above callback
+ * @return handle for the operation on success, NULL on error, i.e.
+ * if the inputs are invalid (i.e. denomination key not with this exchange).
+ * In this case, the callback is not called.
+ */
+struct TALER_EXCHANGE_ReserveWithdrawHandle *
+TALER_EXCHANGE_reserve_withdraw (struct TALER_EXCHANGE_Handle *exchange,
+ const struct TALER_EXCHANGE_DenomPublicKey *pk,
+ const struct TALER_ReservePrivateKeyP *reserve_priv,
+ const struct TALER_PlanchetSecretsP *ps,
+ TALER_EXCHANGE_ReserveWithdrawResultCallback res_cb,
+ void *res_cb_cls)
+{
+ struct TALER_Amount amount_with_fee;
+ struct TALER_ReserveSignatureP reserve_sig;
+ struct TALER_WithdrawRequestPS req;
+ struct TALER_PlanchetDetail pd;
+ struct TALER_EXCHANGE_ReserveWithdrawHandle *wsh;
+
+ GNUNET_CRYPTO_eddsa_key_get_public (&reserve_priv->eddsa_priv,
+ &req.reserve_pub.eddsa_pub);
+ req.purpose.size = htonl (sizeof (struct TALER_WithdrawRequestPS));
+ req.purpose.purpose = htonl (TALER_SIGNATURE_WALLET_RESERVE_WITHDRAW);
+ if (GNUNET_OK !=
+ TALER_amount_add (&amount_with_fee,
+ &pk->fee_withdraw,
+ &pk->value))
+ {
+ /* exchange gave us denomination keys that overflow like this!? */
+ GNUNET_break_op (0);
+ return NULL;
+ }
+ TALER_amount_hton (&req.amount_with_fee,
+ &amount_with_fee);
+ TALER_amount_hton (&req.withdraw_fee,
+ &pk->fee_withdraw);
+ if (GNUNET_OK !=
+ TALER_planchet_prepare (&pk->key,
+ ps,
+ &pd))
+ {
+ GNUNET_break_op (0);
+ return NULL;
+ }
+ req.h_denomination_pub = pd.denom_pub_hash;
+ GNUNET_CRYPTO_hash (pd.coin_ev,
+ pd.coin_ev_size,
+ &req.h_coin_envelope);
+ GNUNET_assert (GNUNET_OK ==
+ GNUNET_CRYPTO_eddsa_sign (&reserve_priv->eddsa_priv,
+ &req.purpose,
+ &reserve_sig.eddsa_signature));
+ wsh = reserve_withdraw_internal (exchange,
+ pk,
+ &reserve_sig,
+ &req.reserve_pub,
+ ps,
+ &pd,
+ res_cb,
+ res_cb_cls);
+ GNUNET_free (pd.coin_ev);
+ return wsh;
+}
+
+
+/**
+ * Withdraw a coin from the exchange using a /reserve/withdraw
+ * request. This API is typically used by a wallet to withdraw a tip
+ * where the reserve's signature was created by the merchant already.
+ *
+ * Note that to ensure that no money is lost in case of hardware
+ * failures, the caller must have committed (most of) the arguments to
+ * disk before calling, and be ready to repeat the request with the
+ * same arguments in case of failures.
+ *
+ * @param exchange the exchange handle; the exchange must be ready to operate
+ * @param pk kind of coin to create
+ * @param reserve_sig signature from the reserve authorizing the withdrawal
+ * @param reserve_pub public key of the reserve to withdraw from
+ * @param ps secrets of the planchet
+ * caller must have committed this value to disk before the call (with @a pk)
+ * @param res_cb the callback to call when the final result for this request is available
+ * @param res_cb_cls closure for @a res_cb
+ * @return NULL
+ * if the inputs are invalid (i.e. denomination key not with this exchange).
+ * In this case, the callback is not called.
+ */
+struct TALER_EXCHANGE_ReserveWithdrawHandle *
+TALER_EXCHANGE_reserve_withdraw2 (struct TALER_EXCHANGE_Handle *exchange,
+ const struct TALER_EXCHANGE_DenomPublicKey *pk,
+ const struct TALER_ReserveSignatureP *reserve_sig,
+ const struct TALER_ReservePublicKeyP *reserve_pub,
+ const struct TALER_PlanchetSecretsP *ps,
+ TALER_EXCHANGE_ReserveWithdrawResultCallback res_cb,
+ void *res_cb_cls)
+{
+ struct TALER_EXCHANGE_ReserveWithdrawHandle *wsh;
+ struct TALER_PlanchetDetail pd;
+
+ if (GNUNET_OK !=
+ TALER_planchet_prepare (&pk->key,
+ ps,
+ &pd))
+ {
+ GNUNET_break_op (0);
+ return NULL;
+ }
+ wsh = reserve_withdraw_internal (exchange,
+ pk,
+ reserve_sig,
+ reserve_pub,
+ ps,
+ &pd,
+ res_cb,
+ res_cb_cls);
+ GNUNET_free (pd.coin_ev);
+ return wsh;
+}
+
+
+/**
+ * Cancel a withdraw status request. This function cannot be used
+ * on a request handle if a response is already served for it.
+ *
+ * @param sign the withdraw sign request handle
+ */
+void
+TALER_EXCHANGE_reserve_withdraw_cancel (struct TALER_EXCHANGE_ReserveWithdrawHandle *sign)
+{
+ if (NULL != sign->job)
+ {
+ GNUNET_CURL_job_cancel (sign->job);
+ sign->job = NULL;
+ }
+ GNUNET_free (sign->url);
+ GNUNET_free (sign->json_enc);
+ GNUNET_free (sign);
+}
+
+
+/* end of exchange_api_reserve.c */