more work on crypto RSA helper

ChangeLog

@@ -1,3 +1,10 @@
+Sat 14 Nov 2020 05:47:30 PM CET
+    Modify taler-exchange-transfer to continue even after a
+    wire transfer failed due to the bank refusing it because
+    the target account does not exist. Changed the database
+    to track such failures in the respective table.
+    Opens new issue #6647.  -CG
+
 Tue 10 Nov 2020 01:03:22 PM CET
     Updates to error codes and HTTP status codes for improved
     consistency. Fixed spelling issues. Ensure main() returns

src/exchange/taler-exchange-transfer.c

@@ -264,8 +264,26 @@ wire_confirm_cb (void *cls,
   (void) row_id;
   (void) wire_timestamp;
   wpd->eh = NULL;
-  if (MHD_HTTP_OK != http_status_code)
+  switch (http_status_code)
   {
+  case MHD_HTTP_OK:
+    qs = db_plugin->wire_prepare_data_mark_finished (db_plugin->cls,
+                                                     session,
+                                                     wpd->row_id);
+    /* continued below */
+    break;
+  case MHD_HTTP_NOT_FOUND:
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Wire transaction %llu failed: %u/%d\n",
+                (unsigned long long) wpd->row_id,
+                http_status_code,
+                ec);
+    qs = db_plugin->wire_prepare_data_mark_failed (db_plugin->cls,
+                                                   session,
+                                                   wpd->row_id);
+    /* continued below */
+    break;
+  default:
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Wire transaction failed: %u/%d\n",
                 http_status_code,
@@ -278,9 +296,6 @@ wire_confirm_cb (void *cls,
     wpd = NULL;
     return;
   }
-  qs = db_plugin->wire_prepare_data_mark_finished (db_plugin->cls,
-                                                   session,
-                                                   wpd->row_id);
   if (0 >= qs)
   {
     GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);

src/exchangedb/Makefile.am

@@ -17,7 +17,9 @@ sqldir = $(prefix)/share/taler/sql/exchange/
 sql_DATA = \
   exchange-0000.sql \
   exchange-0001.sql \
-  drop0001.sql
+  exchange-0002.sql \
+  drop0001.sql \
+  drop0002.sql
 
 EXTRA_DIST = \
   exchangedb.conf \

src/exchangedb/drop0002.sql

@@ -0,0 +1,26 @@
+--
+-- This file is part of TALER
+-- Copyright (C) 2020 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/>
+--
+
+-- Everything in one big transaction
+BEGIN;
+
+-- exchange-0002 did not create new tables, so nothing to do here.
+
+-- Unregister patch (0002.sql)
+SELECT _v.unregister_patch('exchange-0002');
+
+-- And we're out of here...
+COMMIT;

src/exchangedb/exchange-0002.sql

@@ -0,0 +1,48 @@
+--
+-- This file is part of TALER
+-- Copyright (C) 2020 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/>
+--
+
+-- Everything in one big transaction
+BEGIN;
+
+-- Check patch versioning is in place.
+SELECT _v.register_patch('exchange-0002', NULL, NULL);
+
+ALTER TABLE prewire
+  ADD failed BOOLEAN NOT NULL DEFAULT false;
+
+COMMENT ON COLUMN prewire.failed
+  IS 'set to TRUE if the bank responded with a non-transient failure to our transfer request';
+COMMENT ON COLUMN prewire.finished
+  IS 'set to TRUE once bank confirmed receiving the wire transfer request';
+COMMENT ON COLUMN prewire.buf
+  IS 'serialized data to send to the bank to execute the wire transfer';
+
+-- change comment, existing index is still useful, but only for gc_prewire.
+COMMENT ON INDEX prepare_iteration_index
+  IS 'for gc_prewire';
+
+-- need a new index for updated wire_prepare_data_get statement:
+CREATE INDEX IF NOT EXISTS prepare_get_index
+  ON prewire
+  (failed,finished);
+COMMENT ON INDEX prepare_get_index
+  IS 'for wire_prepare_data_get';
+
+
+
+
+-- Complete transaction
+COMMIT;

src/exchangedb/plugin_exchangedb_postgres.c

@@ -1098,7 +1098,13 @@ postgres_get_session (void *cls)
       /* Used in #postgres_wire_prepare_data_mark_finished() */
       GNUNET_PQ_make_prepare ("wire_prepare_data_mark_done",
                               "UPDATE prewire"
-                              " SET finished=true"
+                              " SET finished=TRUE"
+                              " WHERE prewire_uuid=$1;",
+                              1),
+      /* Used in #postgres_wire_prepare_data_mark_failed() */
+      GNUNET_PQ_make_prepare ("wire_prepare_data_mark_failed",
+                              "UPDATE prewire"
+                              " SET failed=TRUE"
                               " WHERE prewire_uuid=$1;",
                               1),
       /* Used in #postgres_wire_prepare_data_get() */
@@ -1108,11 +1114,11 @@ postgres_get_session (void *cls)
                               ",type"
                               ",buf"
                               " FROM prewire"
-                              " WHERE finished=false"
+                              " WHERE finished=FALSE"
+                              "   AND failed=FALSE"
                               " ORDER BY prewire_uuid ASC"
                               " LIMIT 1;",
                               0),
-
       /* Used in #postgres_select_deposits_missing_wire */
       GNUNET_PQ_make_prepare ("deposits_get_overdue",
                               "SELECT"
@@ -5224,9 +5230,9 @@ postgres_wire_prepare_data_insert (void *cls,
  * @return transaction status code
  */
 static enum GNUNET_DB_QueryStatus
-postgres_wire_prepare_data_mark_finished (void *cls,
-                                          struct TALER_EXCHANGEDB_Session *
-                                          session,
+postgres_wire_prepare_data_mark_finished (
+  void *cls,
+  struct TALER_EXCHANGEDB_Session *session,
   uint64_t rowid)
 {
   struct GNUNET_PQ_QueryParam params[] = {
@@ -5241,6 +5247,32 @@ postgres_wire_prepare_data_mark_finished (void *cls,
 }
 
 
+/**
+ * Function called to mark wire transfer commit data as failed.
+ *
+ * @param cls closure
+ * @param session database connection
+ * @param rowid which entry to mark as failed
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_wire_prepare_data_mark_failed (
+  void *cls,
+  struct TALER_EXCHANGEDB_Session *session,
+  uint64_t rowid)
+{
+  struct GNUNET_PQ_QueryParam params[] = {
+    GNUNET_PQ_query_param_uint64 (&rowid),
+    GNUNET_PQ_query_param_end
+  };
+
+  (void) cls;
+  return GNUNET_PQ_eval_prepared_non_select (session->conn,
+                                             "wire_prepare_data_mark_failed",
+                                             params);
+}
+
+
 /**
  * Function called to get an unfinished wire transfer
  * preparation data. Fetches at most one item.
@@ -7379,6 +7411,8 @@ libtaler_plugin_exchangedb_postgres_init (void *cls)
   plugin->wire_prepare_data_insert = &postgres_wire_prepare_data_insert;
   plugin->wire_prepare_data_mark_finished =
     &postgres_wire_prepare_data_mark_finished;
+  plugin->wire_prepare_data_mark_failed =
+    &postgres_wire_prepare_data_mark_failed;
   plugin->wire_prepare_data_get = &postgres_wire_prepare_data_get;
   plugin->start_deferred_wire_out = &postgres_start_deferred_wire_out;
   plugin->store_wire_transfer_out = &postgres_store_wire_transfer_out;

src/include/taler_exchangedb_plugin.h

@@ -2429,6 +2429,20 @@ struct TALER_EXCHANGEDB_Plugin
                                      uint64_t rowid);
 
 
+  /**
+   * Function called to mark wire transfer as failed.
+   *
+   * @param cls closure
+   * @param session database connection
+   * @param rowid which entry to mark as failed
+   * @return transaction status code
+   */
+  enum GNUNET_DB_QueryStatus
+  (*wire_prepare_data_mark_failed)(void *cls,
+                                   struct TALER_EXCHANGEDB_Session *session,
+                                   uint64_t rowid);
+
+
   /**
    * Function called to get an unfinished wire transfer
    * preparation data. Fetches at most one item.

src/util/taler-helper-crypto-rsa.h

@@ -0,0 +1,90 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2020 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 util/taler-helper-crypto-rsa.h
+ * @brief IPC messages for the RSA crypto helper.
+ * @author Christian Grothoff
+ */
+#ifndef TALER_HELPER_CRYPTO_RSA_H
+#define TALER_HELPER_CRYPTO_RSA_H
+
+GNUNET_NETWORK_STRUCT_BEGIN
+
+/**
+ * Message sent if a key is available.
+ */
+struct TALER_CRYPTO_RsaKeyAvailableNotification
+{
+  /**
+   * Type is PURGE.
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * Number of bytes of the public key.
+   */
+  uint16_t pub_size;
+
+  /**
+   * Number of bytes of the section name.
+   */
+  uint16_t section_name;
+
+  /**
+   * When does the key become available?
+   */
+  struct GNUNET_TIME_AbsoluteNBO anchor_time;
+
+  /**
+   * How long is the key available after @e anchor_time?
+   */
+  struct GNUNET_TIME_RelativeNBO duration_withdraw;
+
+  /* followed by @e pub_size bytes of the public key */
+
+  /* followed by @e section_name bytes of the configuration section name
+     of the denomination of this key */
+
+};
+
+
+/**
+ * Message sent if a key was purged.
+ */
+struct TALER_CRYPTO_RsaKeyPurgeNotification
+{
+  /**
+   * Type is PURGE.
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * For now, always zero.
+   */
+  uint32_t reserved;
+
+  /**
+   * Hash of the public key of the purged RSA key.
+   */
+  struct GNUNET_HashCode h_denom_pub;
+
+};
+
+
+GNUNET_NETWORK_STRUCT_END
+
+
+#endif