implementing parsing of /refund requests

1 files changed, 146 insertions, 0 deletions

diff --git a/src/exchange/taler-exchange-httpd_refund.c b/src/exchange/taler-exchange-httpd_refund.c
new file mode 100644
index 00000000..c5f24000
--- /dev/null
+++ b/src/exchange/taler-exchange-httpd_refund.c
@@ -0,0 +1,146 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014, 2015, 2016 Inria and GNUnet e.V.
+
+  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, If not, see <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file taler-exchange-httpd_refund.c
+ * @brief Handle /refund requests; parses the POST and JSON and
+ *        verifies the coin signature before handing things off
+ *        to the database.
+ * @author Florian Dold
+ * @author Benedikt Mueller
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <gnunet/gnunet_util_lib.h>
+#include <gnunet/gnunet_json_lib.h>
+#include <jansson.h>
+#include <microhttpd.h>
+#include <pthread.h>
+#include "taler_json_lib.h"
+#include "taler-exchange-httpd_parsing.h"
+#include "taler-exchange-httpd_refund.h"
+#include "taler-exchange-httpd_responses.h"
+#include "taler-exchange-httpd_keystate.h"
+#include "taler-exchange-httpd_validation.h"
+
+
+/**
+ * We have parsed the JSON information about the refund, do some basic
+ * sanity checks (especially that the signature on the coin is valid)
+ * and then execute the refund.  Note that we need the DB to check
+ * the fee structure, so this is not done here.
+ *
+ * @param connection the MHD connection to handle
+ * @param refund information about the refund
+ * @return MHD result code
+ */
+static int
+verify_and_execute_refund (struct MHD_Connection *connection,
+			   const struct TALER_EXCHANGEDB_Refund *refund)
+{
+  struct TALER_RefundRequestPS dr;
+
+  dr.purpose.purpose = htonl (TALER_SIGNATURE_MERCHANT_REFUND);
+  dr.purpose.size = htonl (sizeof (struct TALER_RefundRequestPS));
+  dr.h_contract = refund->h_contract;
+  dr.transaction_id = GNUNET_htonll (refund->transaction_id);
+  dr.rtransaction_id = GNUNET_htonll (refund->rtransaction_id);
+  TALER_amount_hton (&dr.refund_amount,
+                     &refund->refund_amount);
+  TALER_amount_hton (&dr.refund_fee,
+                     &refund->refund_fee);
+  dr.merchant = refund->merchant_pub;
+  dr.coin_pub = refund->coin.coin_pub;
+  if (GNUNET_OK !=
+      GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_MERCHANT_REFUND,
+                                  &dr.purpose,
+                                  &refund->merchant_sig.eddsa_sig,
+                                  &refund->merchant_pub.eddsa_pub))
+  {
+    TALER_LOG_WARNING ("Invalid signature on /refund request\n");
+    return TMH_RESPONSE_reply_signature_invalid (connection,
+                                                 "merchant_sig");
+  }
+#if 1
+  GNUNET_break (0); // FIXME: not implemented
+  return MHD_NO;
+#else
+  return TMH_DB_execute_refund (connection,
+				refund);
+#endif
+}
+
+
+/**
+ * Handle a "/refund" request.  Parses the JSON, and, if successful,
+ * passes the JSON data to #parse_and_handle_refund_request() to
+ * further check the details of the operation specified.  If
+ * everything checks out, this will ultimately lead to the "/refund"
+ * being executed, or rejected.
+ *
+ * @param rh context of the handler
+ * @param connection the MHD connection to handle
+ * @param[in,out] connection_cls the connection's closure (can be updated)
+ * @param upload_data upload data
+ * @param[in,out] upload_data_size number of bytes (left) in @a upload_data
+ * @return MHD result code
+  */
+int
+TMH_REFUND_handler_refund (struct TMH_RequestHandler *rh,
+			   struct MHD_Connection *connection,
+			   void **connection_cls,
+			   const char *upload_data,
+			   size_t *upload_data_size)
+{
+  json_t *json;
+  int res;
+  struct TALER_EXCHANGEDB_Refund refund;
+  struct GNUNET_JSON_Specification spec[] = {
+    TALER_JSON_spec_amount ("refund_amount", &refund.refund_amount),
+    TALER_JSON_spec_amount ("refund_fee", &refund.refund_fee),
+    GNUNET_JSON_spec_fixed_auto ("H_contract", &refund.h_contract),
+    GNUNET_JSON_spec_uint64 ("transaction_id", &refund.transaction_id),
+    GNUNET_JSON_spec_fixed_auto ("coin_pub", &refund.coin.coin_pub),
+    GNUNET_JSON_spec_fixed_auto ("merchant_pub", &refund.merchant_pub),
+    GNUNET_JSON_spec_uint64 ("rtransaction_id", &refund.rtransaction_id),
+    GNUNET_JSON_spec_fixed_auto ("merchant_sig", &refund.merchant_sig),
+    GNUNET_JSON_spec_end ()
+  };
+
+  res = TMH_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;
+  res = TMH_PARSE_json_data (connection,
+                             json,
+                             spec);
+  json_decref (json);
+  if (GNUNET_SYSERR == res)
+    return MHD_NO; /* hard failure */
+  if (GNUNET_NO == res)
+    return MHD_YES; /* failure */
+  res = verify_and_execute_refund (connection,
+				   &refund);
+  GNUNET_JSON_parse_free (spec);
+  return res;
+}
+
+
+/* end of taler-exchange-httpd_refund.c */