major refactoring, eliminating wire-plugins and moving towards new bank API. main code compiles, testcases known to fail, code sure not to fully work yet

5 files changed, 296 insertions, 583 deletions

diff --git a/src/exchange/Makefile.am b/src/exchange/Makefile.am
index 3453683ae..b08c85c6f 100644
--- a/src/exchange/Makefile.am
+++ b/src/exchange/Makefile.am
@@ -29,9 +29,11 @@ taler_exchange_aggregator_LDADD = \
   $(LIBGCRYPT_LIBS) \
   $(top_builddir)/src/json/libtalerjson.la \
   $(top_builddir)/src/util/libtalerutil.la \
+  $(top_builddir)/src/bank-lib/libtalerbank.la \
   $(top_builddir)/src/wire/libtalerwire.la \
   $(top_builddir)/src/exchangedb/libtalerexchangedb.la \
   -ljansson \
+  -lgnunetcurl \
   -lgnunetutil
 
 taler_exchange_wirewatch_SOURCES = \
@@ -40,9 +42,11 @@ taler_exchange_wirewatch_LDADD = \
   $(LIBGCRYPT_LIBS) \
   $(top_builddir)/src/json/libtalerjson.la \
   $(top_builddir)/src/util/libtalerutil.la \
+  $(top_builddir)/src/bank-lib/libtalerbank.la \
   $(top_builddir)/src/wire/libtalerwire.la \
   $(top_builddir)/src/exchangedb/libtalerexchangedb.la \
   -ljansson \
+  -lgnunetcurl \
   -lgnunetutil
 
 taler_exchange_httpd_SOURCES = \
@@ -66,6 +70,7 @@ taler_exchange_httpd_SOURCES = \
   taler-exchange-httpd_validation.c taler-exchange-httpd_validation.h
 taler_exchange_httpd_LDADD = \
   $(LIBGCRYPT_LIBS) \
+  $(top_builddir)/src/bank-lib/libtalerbank.la \
   $(top_builddir)/src/wire/libtalerwire.la \
   $(top_builddir)/src/mhd/libtalermhd.la \
   $(top_builddir)/src/json/libtalerjson.la \
diff --git a/src/exchange/taler-exchange-aggregator.c b/src/exchange/taler-exchange-aggregator.c
index 71a3efd7d..2704f5910 100644
--- a/src/exchange/taler-exchange-aggregator.c
+++ b/src/exchange/taler-exchange-aggregator.c
@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  Copyright (C) 2016-2018 Taler Systems SA
+  Copyright (C) 2016-2020 Taler Systems SA
 
   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
@@ -26,6 +26,7 @@
 #include "taler_exchangedb_lib.h"
 #include "taler_exchangedb_plugin.h"
 #include "taler_json_lib.h"
+#include "taler_bank_service.h"
 #include "taler_wire_lib.h"
 
 
@@ -45,9 +46,14 @@ struct WireAccount
   struct WireAccount *prev;
 
   /**
-   * Handle to the plugin.
+   * Account information.
    */
-  struct TALER_WIRE_Plugin *wire_plugin;
+  struct TALER_Account account;
+
+  /**
+   * Authentication data.
+   */
+  struct TALER_BANK_AuthenticationData auth;
 
   /**
    * Wire transfer fee structure.
@@ -59,6 +65,11 @@ struct WireAccount
    */
   char *section_name;
 
+  /**
+   * Name of the wire method underlying the account.
+   */
+  char *method;
+
 };
 
 
@@ -77,7 +88,7 @@ struct WirePrepareData
   /**
    * Wire execution handle.
    */
-  struct TALER_WIRE_ExecuteHandle *eh;
+  struct TALER_BANK_WireExecuteHandle *eh;
 
   /**
    * Wire plugin used for this preparation.
@@ -187,10 +198,6 @@ struct AggregationUnit
  */
 struct CloseTransferContext
 {
-  /**
-   * Handle for preparing the wire transfer.
-   */
-  struct TALER_WIRE_PrepareHandle *ph;
 
   /**
    * Our database session.
@@ -263,6 +270,16 @@ static struct WirePrepareData *wpd;
 static struct AggregationUnit *au;
 
 /**
+ * Handle to the context for interacting with the bank.
+ */
+static struct GNUNET_CURL_Context *ctx;
+
+/**
+ * Scheduler context for running the @e ctx.
+ */
+static struct GNUNET_CURL_RescheduleContext *rc;
+
+/**
  * Value to return from main(). #GNUNET_OK on success, #GNUNET_SYSERR
  * on serious errors.
  */
@@ -339,7 +356,7 @@ update_fees (struct WireAccount *wa,
     return GNUNET_DB_STATUS_SUCCESS_ONE_RESULT;
   /* Let's try to load it from disk... */
   wa->af = TALER_EXCHANGEDB_fees_read (cfg,
-                                       wa->wire_plugin->method);
+                                       wa->method);
   advance_fees (wa,
                 now);
   for (struct TALER_EXCHANGEDB_AggregateFees *p = wa->af;
@@ -348,7 +365,7 @@ update_fees (struct WireAccount *wa,
   {
     qs = db_plugin->insert_wire_fee (db_plugin->cls,
                                      session,
-                                     wa->wire_plugin->method,
+                                     wa->method,
                                      p->start_date,
                                      p->end_date,
                                      &p->wire_fee,
@@ -365,7 +382,7 @@ update_fees (struct WireAccount *wa,
     return GNUNET_DB_STATUS_SUCCESS_ONE_RESULT;
   GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
               "Failed to find current wire transfer fees for `%s'\n",
-              wa->wire_plugin->method);
+              wa->method);
   return GNUNET_DB_STATUS_SUCCESS_NO_RESULTS;
 }
 
@@ -381,7 +398,7 @@ find_account_by_method (const char *method)
 {
   for (struct WireAccount *wa = wa_head; NULL != wa; wa = wa->next)
     if (0 == strcmp (method,
-                     wa->wire_plugin->method))
+                     wa->method))
       return wa;
   return NULL;
 }
@@ -431,13 +448,40 @@ add_account_cb (void *cls,
   if (GNUNET_YES != ai->debit_enabled)
     return; /* not enabled for us, skip */
   wa = GNUNET_new (struct WireAccount);
-  wa->wire_plugin = TALER_WIRE_plugin_load (cfg,
-                                            ai->plugin_name);
-  if (NULL == wa->wire_plugin)
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_string (cfg,
+                                             ai->section_name,
+                                             "METHOD",
+                                             &wa->method))
   {
-    fprintf (stderr,
-             "Failed to load wire plugin for `%s'\n",
-             ai->plugin_name);
+    GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
+                               ai->section_name,
+                               "METHOD");
+    GNUNET_free (wa);
+    return;
+  }
+  if (GNUNET_OK !=
+      TALER_BANK_auth_parse_cfg (cfg,
+                                 ai->section_name,
+                                 &wa->auth))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_MESSAGE,
+                "Failed to load account `%s'\n",
+                ai->section_name);
+    GNUNET_free (wa->method);
+    GNUNET_free (wa);
+    return;
+  }
+  if (GNUNET_OK !=
+      TALER_BANK_account_parse_cfg (cfg,
+                                    ai->section_name,
+                                    &wa->account))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_MESSAGE,
+                "Failed to load account `%s'\n",
+                ai->section_name);
+    TALER_BANK_auth_free (&wa->auth);
+    GNUNET_free (wa->method);
     GNUNET_free (wa);
     return;
   }
@@ -476,6 +520,16 @@ static void
 shutdown_task (void *cls)
 {
   (void) cls;
+  if (NULL != ctx)
+  {
+    GNUNET_CURL_fini (ctx);
+    ctx = NULL;
+  }
+  if (NULL != rc)
+  {
+    GNUNET_CURL_gnunet_rc_destroy (rc);
+    rc = NULL;
+  }
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
               "Running shutdown\n");
   if (NULL != task)
@@ -487,9 +541,7 @@ shutdown_task (void *cls)
   {
     if (NULL != wpd->eh)
     {
-      wpd->wa->wire_plugin->execute_wire_transfer_cancel (
-        wpd->wa->wire_plugin->cls,
-        wpd->eh);
+      TALER_BANK_execute_wire_transfer_cancel (wpd->eh);
       wpd->eh = NULL;
     }
     db_plugin->rollback (db_plugin->cls,
@@ -499,23 +551,12 @@ shutdown_task (void *cls)
   }
   if (NULL != au)
   {
-    if (NULL != au->ph)
-    {
-      au->wa->wire_plugin->prepare_wire_transfer_cancel (
-        au->wa->wire_plugin->cls,
-        au->ph);
-      au->ph = NULL;
-    }
     db_plugin->rollback (db_plugin->cls,
                          au->session);
     cleanup_au ();
   }
   if (NULL != ctc)
   {
-    ctc->wa->wire_plugin->prepare_wire_transfer_cancel (
-      ctc->wa->wire_plugin->cls,
-      ctc->ph);
-    ctc->ph = NULL;
     db_plugin->rollback (db_plugin->cls,
                          ctc->session);
     GNUNET_free (ctc->method);
@@ -532,9 +573,11 @@ shutdown_task (void *cls)
       GNUNET_CONTAINER_DLL_remove (wa_head,
                                    wa_tail,
                                    wa);
-      TALER_WIRE_plugin_unload (wa->wire_plugin);
+      TALER_WIRE_account_free (&wa->account);
+      TALER_BANK_auth_free (&wa->auth);
       TALER_EXCHANGEDB_fees_free (wa->af);
       GNUNET_free (wa->section_name);
+      GNUNET_free (wa->method);
       GNUNET_free (wa);
     }
   }
@@ -922,20 +965,6 @@ aggregate_cb (void *cls,
 
 
 /**
- * Function to be called with the prepared transfer data
- * when running an aggregation on a merchant.
- *
- * @param cls closure with the `struct AggregationUnit`
- * @param buf transaction data to persist, NULL on error
- * @param buf_size number of bytes in @a buf, 0 on error
- */
-static void
-prepare_cb (void *cls,
-            const char *buf,
-            size_t buf_size);
-
-
-/**
  * Main work function that finds and triggers transfers for reserves
  * closures.
  *
@@ -989,83 +1018,6 @@ commit_or_warn (struct TALER_EXCHANGEDB_Session *session)
 
 
 /**
- * Function to be called with the prepared transfer data
- * when closing a reserve.
- *
- * @param cls closure with a `struct CloseTransferContext`
- * @param buf transaction data to persist, NULL on error
- * @param buf_size number of bytes in @a buf, 0 on error
- */
-static void
-prepare_close_cb (void *cls,
-                  const char *buf,
-                  size_t buf_size)
-{
-  enum GNUNET_DB_QueryStatus qs;
-
-  GNUNET_assert (cls == ctc);
-
-  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-              "Prepared for reserve closing\n");
-  ctc->ph = NULL;
-  if (NULL == buf)
-  {
-    GNUNET_break (0); /* why? how to best recover? */
-    db_plugin->rollback (db_plugin->cls,
-                         ctc->session);
-    /* start again */
-    GNUNET_free (ctc->method);
-    GNUNET_free (ctc);
-    ctc = NULL;
-    task = GNUNET_SCHEDULER_add_now (&run_aggregation,
-                                     NULL);
-    return;
-  }
-
-  /* Commit our intention to execute the wire transfer! */
-  qs = db_plugin->wire_prepare_data_insert (db_plugin->cls,
-                                            ctc->session,
-                                            ctc->method,
-                                            buf,
-                                            buf_size);
-  if (GNUNET_DB_STATUS_HARD_ERROR == qs)
-  {
-    GNUNET_break (0);
-    db_plugin->rollback (db_plugin->cls,
-                         ctc->session);
-    global_ret = GNUNET_SYSERR;
-    GNUNET_SCHEDULER_shutdown ();
-    GNUNET_free (ctc->method);
-    GNUNET_free (ctc);
-    ctc = NULL;
-    return;
-  }
-  if (GNUNET_DB_STATUS_SOFT_ERROR == qs)
-  {
-    db_plugin->rollback (db_plugin->cls,
-                         ctc->session);
-    /* start again */
-    task = GNUNET_SCHEDULER_add_now (&run_aggregation,
-                                     NULL);
-    GNUNET_free (ctc->method);
-    GNUNET_free (ctc);
-    ctc = NULL;
-    return;
-  }
-
-  /* finally commit */
-  (void) commit_or_warn (ctc->session);
-  GNUNET_free (ctc->method);
-  GNUNET_free (ctc);
-  ctc = NULL;
-  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-              "Reserve closure committed, running transfer\n");
-  task = GNUNET_SCHEDULER_add_now (&run_transfers,
-                                   NULL);
-}
-
-
-/**
  * Closure for #expired_reserve_cb().
  */
 struct ExpiredReserveContext
@@ -1113,6 +1065,8 @@ expired_reserve_cb (void *cls,
   int ret;
   enum GNUNET_DB_QueryStatus qs;
   struct WireAccount *wa;
+  void *buf;
+  size_t buf_size;
 
   /* NOTE: potential optimization: use custom SQL API to not
      fetch this: */
@@ -1121,7 +1075,7 @@ expired_reserve_cb (void *cls,
   now = GNUNET_TIME_absolute_get ();
   (void) GNUNET_TIME_round_abs (&now);
 
-  /* lookup wire plugin */
+  /* lookup account we should use */
   wa = find_account_by_url (account_details);
   if (NULL == wa)
   {
@@ -1161,6 +1115,18 @@ expired_reserve_cb (void *cls,
                    TALER_amount_get_zero (left->currency,
                                           &amount_without_fee));
   }
+  /* round down to enable transfer */
+  if (GNUNET_SYSERR ==
+      TALER_WIRE_amount_round (&amount_without_fee))
+  {
+    GNUNET_break (0);
+    global_ret = GNUNET_SYSERR;
+    GNUNET_SCHEDULER_shutdown ();
+    return GNUNET_DB_STATUS_HARD_ERROR;
+  }
+  if ( (0 == amount_without_fee.value) &&
+       (0 == amount_without_fee.fraction) )
+    ret = GNUNET_NO;
 
   /* NOTE: sizeof (*reserve_pub) == sizeof (wtid) right now, but to
      be future-compatible, we use the memset + min construction */
@@ -1171,61 +1137,23 @@ expired_reserve_cb (void *cls,
           reserve_pub,
           GNUNET_MIN (sizeof (wtid),
                       sizeof (*reserve_pub)));
-
-  qs = db_plugin->insert_reserve_closed (db_plugin->cls,
-                                         session,
-                                         reserve_pub,
-                                         now,
-                                         account_details,
-                                         &wtid,
-                                         left,
-                                         closing_fee);
-
+  if (GNUNET_SYSERR != ret)
+    qs = db_plugin->insert_reserve_closed (db_plugin->cls,
+                                           session,
+                                           reserve_pub,
+                                           now,
+                                           account_details,
+                                           &wtid,
+                                           left,
+                                           closing_fee);
+  else
+    ret = GNUNET_DB_STATUS_HARD_ERROR;
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
               "Closing reserve %s over %s (%d, %d)\n",
               TALER_B2S (reserve_pub),
               TALER_amount2s (left),
               ret,
               qs);
-  if ( (GNUNET_OK == ret) &&
-       (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT == qs) )
-  {
-    /* success, perform wire transfer */
-    if (GNUNET_SYSERR ==
-        wa->wire_plugin->amount_round (wa->wire_plugin->cls,
-                                       &amount_without_fee))
-    {
-      GNUNET_break (0);
-      global_ret = GNUNET_SYSERR;
-      GNUNET_SCHEDULER_shutdown ();
-      return GNUNET_DB_STATUS_HARD_ERROR;
-    }
-    ctc = GNUNET_new (struct CloseTransferContext);
-    ctc->wa = wa;
-    ctc->session = session;
-    ctc->method = TALER_WIRE_payto_get_method (account_details);
-    ctc->ph
-      = wa->wire_plugin->prepare_wire_transfer (wa->wire_plugin->cls,
-                                                wa->section_name,
-                                                account_details,
-                                                &amount_without_fee,
-                                                exchange_base_url,
-                                                &wtid,
-                                                &prepare_close_cb,
-                                                ctc);
-    if (NULL == ctc->ph)
-    {
-      GNUNET_break (0);
-      global_ret = GNUNET_SYSERR;
-      GNUNET_SCHEDULER_shutdown ();
-      GNUNET_free (ctc->method);
-      GNUNET_free (ctc);
-      ctc = NULL;
-      return GNUNET_DB_STATUS_HARD_ERROR;
-    }
-    erc->async_cont = GNUNET_YES;
-    return GNUNET_DB_STATUS_SUCCESS_ONE_RESULT;
-  }
   /* Check for hard failure */
   if ( (GNUNET_SYSERR == ret) ||
        (GNUNET_DB_STATUS_HARD_ERROR == qs) )
@@ -1235,10 +1163,59 @@ expired_reserve_cb (void *cls,
     GNUNET_SCHEDULER_shutdown ();
     return GNUNET_DB_STATUS_HARD_ERROR;
   }
-  /* Reserve balance was almost zero OR soft error */
-  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-              "Reserve was virtually empty, moving on\n");
-  return qs;
+  if ( (GNUNET_OK != ret) ||
+       (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT != qs) )
+  {
+    /* Reserve balance was almost zero OR soft error */
+    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+                "Reserve was virtually empty, moving on\n");
+    (void) commit_or_warn (ctc->session);
+    GNUNET_free (ctc->method);
+    GNUNET_free (ctc);
+    ctc = NULL;
+    task = GNUNET_SCHEDULER_add_now (&run_transfers,
+                                     NULL);
+    return qs;
+  }
+
+  /* success, perform wire transfer */
+  ctc = GNUNET_new (struct CloseTransferContext);
+  ctc->wa = wa;
+  ctc->session = session;
+  ctc->method = TALER_WIRE_payto_get_method (account_details);
+  TALER_BANK_prepare_wire_transfer (account_details,
+                                    &amount_without_fee,
+                                    exchange_base_url,
+                                    &wtid,
+                                    &buf,
+                                    &buf_size);
+  /* Commit our intention to execute the wire transfer! */
+  qs = db_plugin->wire_prepare_data_insert (db_plugin->cls,
+                                            ctc->session,
+                                            ctc->method,
+                                            buf,
+                                            buf_size);
+  GNUNET_free (buf);
+  if (GNUNET_DB_STATUS_HARD_ERROR == qs)
+  {
+    GNUNET_break (0);
+    GNUNET_free (ctc->method);
+    GNUNET_free (ctc);
+    ctc = NULL;
+    return GNUNET_DB_STATUS_HARD_ERROR;
+  }
+  if (GNUNET_DB_STATUS_SOFT_ERROR == qs)
+  {
+    /* start again */
+    GNUNET_free (ctc->method);
+    GNUNET_free (ctc);
+    ctc = NULL;
+    return GNUNET_DB_STATUS_SUCCESS_NO_RESULTS;
+  }
+  erc->async_cont = GNUNET_YES;
+  task = GNUNET_SCHEDULER_add_now (&run_transfers,
+                                   NULL);
+  return GNUNET_DB_STATUS_SUCCESS_ONE_RESULT;
 }
 
 
@@ -1344,6 +1321,8 @@ run_aggregation (void *cls)
   struct TALER_EXCHANGEDB_Session *session;
   enum GNUNET_DB_QueryStatus qs;
   const struct GNUNET_SCHEDULER_TaskContext *tc;
+  void *buf;
+  size_t buf_size;
 
   (void) cls;
   task = NULL;
@@ -1470,8 +1449,7 @@ run_aggregation (void *cls)
                                &au->total_amount,
                                &au->wire_fee)) ||
        (GNUNET_SYSERR ==
-        au->wa->wire_plugin->amount_round (au->wa->wire_plugin->cls,
-                                           &au->final_amount)) ||
+        TALER_WIRE_amount_round (&au->final_amount)) ||
        ( (0 == au->final_amount.value) &&
          (0 == au->final_amount.fraction) ) )
   {
@@ -1555,70 +1533,26 @@ run_aggregation (void *cls)
     char *url;
 
     url = TALER_JSON_wire_to_payto (au->wire);
-    au->ph = au->wa->wire_plugin->prepare_wire_transfer (
-      au->wa->wire_plugin->cls,
-      au->wa->section_name,
-      url,
-      &au->final_amount,
-      exchange_base_url,
-      &au->wtid,
-      &prepare_cb,
-      au);
+    TALER_BANK_prepare_wire_transfer (url,
+                                      &au->final_amount,
+                                      exchange_base_url,
+                                      &au->wtid,
+                                      &buf,
+                                      &buf_size);
     GNUNET_free (url);
   }
-  if (NULL == au->ph)
-  {
-    /* something went very wrong, likely bad configuration,
-       abort */
-    db_plugin->rollback (db_plugin->cls,
-                         session);
-    cleanup_au ();
-    GNUNET_SCHEDULER_shutdown ();
-    return;
-  }
-  /* otherwise we continue with #prepare_cb(), see below */
-}
-
-
-/**
- * Function to be called with the prepared transfer data.
- *
- * @param cls NULL
- * @param buf transaction data to persist, NULL on error
- * @param buf_size number of bytes in @a buf, 0 on error
- */
-static void
-prepare_cb (void *cls,
-            const char *buf,
-            size_t buf_size)
-{
-  struct TALER_EXCHANGEDB_Session *session = au->session;
-  enum GNUNET_DB_QueryStatus qs;
-
-  (void) cls;
   GNUNET_free_non_null (au->additional_rows);
   au->additional_rows = NULL;
-  if (NULL == buf)
-  {
-    GNUNET_break (0); /* why? how to best recover? */
-    db_plugin->rollback (db_plugin->cls,
-                         session);
-    /* start again */
-    task = GNUNET_SCHEDULER_add_now (&run_aggregation,
-                                     NULL);
-    cleanup_au ();
-    return;
-  }
-
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
               "Storing %u bytes of wire prepare data\n",
               (unsigned int) buf_size);
   /* Commit our intention to execute the wire transfer! */
   qs = db_plugin->wire_prepare_data_insert (db_plugin->cls,
                                             session,
-                                            au->wa->wire_plugin->method,
+                                            au->wa->method,
                                             buf,
                                             buf_size);
+  GNUNET_free (buf);
   /* Commit the WTID data to 'wire_out' to finally satisfy aggregation
      table constraints */
   if (qs >= 0)
@@ -1691,29 +1625,30 @@ prepare_cb (void *cls,
  * Function called with the result from the execute step.
  *
  * @param cls NULL
- * @param success #GNUNET_OK on success, #GNUNET_SYSERR on failure
- * @param serial_id unique ID of the wire transfer in the bank's records; UINT64_MAX on error
- * @param emsg NULL on success, otherwise an error message
+ * @param http_status_code #MHD_HTTP_OK on success
+ * @param ec taler error code
+ * @param row_id unique ID of the wire transfer in the bank's records
+ * @param wire_timestamp when did the transfer happen
  */
 static void
 wire_confirm_cb (void *cls,
-                 int success,
-                 const void *row_id,
-                 size_t row_id_size,
-                 const char *emsg)
+                 unsigned int http_status_code,
+                 enum TALER_ErrorCode ec,
+                 uint64_t row_id,
+                 struct GNUNET_TIME_Absolute wire_timestamp)
 {
   struct TALER_EXCHANGEDB_Session *session = wpd->session;
   enum GNUNET_DB_QueryStatus qs;
 
   (void) cls;
   (void) row_id;
-  (void) row_id_size;
   wpd->eh = NULL;
-  if (GNUNET_SYSERR == success)
+  if (MHD_HTTP_OK != http_status_code)
   {
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                "Wire transaction failed: %s\n",
-                emsg);
+                "Wire transaction failed: %u/%d\n",
+                http_status_code,
+                ec);
     db_plugin->rollback (db_plugin->cls,
                          session);
     global_ret = GNUNET_SYSERR;
@@ -1792,6 +1727,8 @@ wire_prepare_cb (void *cls,
                  const char *buf,
                  size_t buf_size)
 {
+  struct WireAccount *wa;
+
   (void) cls;
   wpd->row_id = rowid;
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
@@ -1811,12 +1748,15 @@ wire_prepare_cb (void *cls,
     wpd = NULL;
     return;
   }
-  wpd->eh = wpd->wa->wire_plugin->execute_wire_transfer (
-    wpd->wa->wire_plugin->cls,
-    buf,
-    buf_size,
-    &wire_confirm_cb,
-    NULL);
+  wa = wpd->wa;
+  wpd->eh = TALER_BANK_execute_wire_transfer (ctx,
+                                              wa->account.details.x_taler_bank.
+                                              account_base_url,
+                                              &wa->auth,
+                                              buf,
+                                              buf_size,
+                                              &wire_confirm_cb,
+                                              NULL);
   if (NULL == wpd->eh)
   {
     GNUNET_break (0); /* why? how to best recover? */
@@ -1927,6 +1867,7 @@ run (void *cls,
   (void) cls;
   (void) args;
   (void) cfgfile;
+
   if (GNUNET_OK !=
       GNUNET_CONFIGURATION_get_value_string (c,
                                              "exchange",
@@ -1947,6 +1888,15 @@ run (void *cls,
     global_ret = 1;
     return;
   }
+  ctx = GNUNET_CURL_init (&GNUNET_CURL_gnunet_scheduler_reschedule,
+                          &rc);
+  rc = GNUNET_CURL_gnunet_rc_create (ctx);
+  if (NULL == ctx)
+  {
+    GNUNET_break (0);
+    return;
+  }
+
   task = GNUNET_SCHEDULER_add_now (&run_transfers,
                                    NULL);
   GNUNET_SCHEDULER_add_shutdown (&shutdown_task,
diff --git a/src/exchange/taler-exchange-httpd_deposit.c b/src/exchange/taler-exchange-httpd_deposit.c
index 024482389..96e30e437 100644
--- a/src/exchange/taler-exchange-httpd_deposit.c
+++ b/src/exchange/taler-exchange-httpd_deposit.c
@@ -400,7 +400,6 @@ TEH_DEPOSIT_handler_deposit (struct TEH_RequestHandler *rh,
   json_t *json;
   int res;
   json_t *wire;
-  char *emsg;
   enum TALER_ErrorCode ec;
   unsigned int hc;
   struct TALER_EXCHANGEDB_Deposit deposit;
@@ -460,18 +459,6 @@ TEH_DEPOSIT_handler_deposit (struct TEH_RequestHandler *rh,
                                        "refund_deadline");
   }
 
-  if (TALER_EC_NONE !=
-      (ec = TEH_json_validate_wireformat (wire,
-                                          &emsg)))
-  {
-    GNUNET_JSON_parse_free (spec);
-    res = TALER_MHD_reply_with_error (connection,
-                                      MHD_HTTP_BAD_REQUEST,
-                                      ec,
-                                      emsg);
-    GNUNET_free (emsg);
-    return res;
-  }
   if (GNUNET_OK !=
       check_timestamp_current (deposit.timestamp))
   {
diff --git a/src/exchange/taler-exchange-httpd_validation.c b/src/exchange/taler-exchange-httpd_validation.c
index 23dbbf249..d0371e930 100644
--- a/src/exchange/taler-exchange-httpd_validation.c
+++ b/src/exchange/taler-exchange-httpd_validation.c
@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  Copyright (C) 2016, 2017, 2018 Taler Systems SA
+  Copyright (C) 2016-2020 Taler Systems SA
 
   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
@@ -30,40 +30,6 @@
 
 
 /**
- * Information we keep for each plugin.
- */
-struct Plugin
-{
-
-  /**
-   * We keep plugins in a DLL.
-   */
-  struct Plugin *next;
-
-  /**
-   * We keep plugins in a DLL.
-   */
-  struct Plugin *prev;
-
-  /**
-   * Pointer to the plugin.
-   */
-  struct TALER_WIRE_Plugin *plugin;
-
-};
-
-
-/**
- * Head of DLL of wire plugins.
- */
-static struct Plugin *wire_head;
-
-/**
- * Tail of DLL of wire plugins.
- */
-static struct Plugin *wire_tail;
-
-/**
  * Array of wire methods supported by this exchange.
  */
 static json_t *wire_accounts_array;
@@ -191,9 +157,8 @@ load_account (void *cls,
     else
     {
       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                  "Wire fees not specified for `%s', ignoring plugin %s\n",
-                  method,
-                  ai->plugin_name);
+                  "Wire fees not specified for `%s'\n",
+                  method);
       *ret = GNUNET_SYSERR;
     }
     GNUNET_free (method);
@@ -201,35 +166,15 @@ load_account (void *cls,
 
   if (GNUNET_YES == ai->debit_enabled)
   {
-    struct Plugin *p;
-
-    p = GNUNET_new (struct Plugin);
-    p->plugin = TALER_WIRE_plugin_load (cfg,
-                                        ai->plugin_name);
-    if (NULL == p->plugin)
-    {
-      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                  "Failed to load plugin %s\n",
-                  ai->plugin_name);
-      GNUNET_free (p);
-      *ret = GNUNET_SYSERR;
-      return;
-    }
     if (GNUNET_OK !=
-        load_fee (p->plugin->method))
+        load_fee (ai->method))
     {
       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                  "Disabling plugin `%s' as wire transfer fees for `%s' are not given correctly\n",
-                  ai->plugin_name,
-                  p->plugin->method);
-      TALER_WIRE_plugin_unload (p->plugin);
-      GNUNET_free (p);
+                  "Wire transfer fees for `%s' are not given correctly\n",
+                  ai->method);
       *ret = GNUNET_SYSERR;
       return;
     }
-    GNUNET_CONTAINER_DLL_insert (wire_head,
-                                 wire_tail,
-                                 p);
   }
 }
 
@@ -251,12 +196,6 @@ TEH_VALIDATION_init (const struct GNUNET_CONFIGURATION_Handle *cfg)
   TALER_EXCHANGEDB_find_accounts (cfg,
                                   &load_account,
                                   &ret);
-  if (NULL == wire_head)
-  {
-    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                "Failed to find properly configured wire transfer method\n");
-    ret = GNUNET_SYSERR;
-  }
   if (GNUNET_OK != ret)
     TEH_VALIDATION_done ();
   return ret;
@@ -269,16 +208,6 @@ TEH_VALIDATION_init (const struct GNUNET_CONFIGURATION_Handle *cfg)
 void
 TEH_VALIDATION_done ()
 {
-  struct Plugin *p;
-
-  while (NULL != (p = wire_head))
-  {
-    GNUNET_CONTAINER_DLL_remove (wire_head,
-                                 wire_tail,
-                                 p);
-    TALER_WIRE_plugin_unload (p->plugin);
-    GNUNET_free (p);
-  }
   json_decref (wire_fee_object);
   wire_fee_object = NULL;
   json_decref (wire_accounts_array);
@@ -287,65 +216,6 @@ TEH_VALIDATION_done ()
 
 
 /**
- * Check if the given wire format JSON object is correctly formatted as
- * a wire address.
- *
- * @param wire the JSON wire format object
- * @param[out] emsg set to error message if we return an error code
- * @return #TALER_EC_NONE if correctly formatted; otherwise error code
- */
-enum TALER_ErrorCode
-TEH_json_validate_wireformat (const json_t *wire,
-                              char **emsg)
-{
-  const char *payto_url;
-  json_error_t error;
-  char *method;
-
-  *emsg = NULL;
-  if (0 != json_unpack_ex ((json_t *) wire,
-                           &error, 0,
-                           "{s:s}",
-                           "url", &payto_url))
-  {
-    GNUNET_asprintf (emsg,
-                     "No `url' specified in the wire details\n");
-    return TALER_EC_DEPOSIT_INVALID_WIRE_FORMAT_TYPE_MISSING;
-  }
-  method = TALER_WIRE_payto_get_method (payto_url);
-  if (NULL == method)
-  {
-    GNUNET_asprintf (emsg,
-                     "Malformed payto URL `%s'\n",
-                     payto_url);
-    return TALER_EC_PAYTO_MALFORMED;
-  }
-  for (struct Plugin *p = wire_head; NULL != p; p = p->next)
-  {
-    if (0 == strcasecmp (p->plugin->method,
-                         method))
-    {
-      enum TALER_ErrorCode ec;
-
-      GNUNET_free (method);
-      ec = p->plugin->wire_validate (p->plugin->cls,
-                                     payto_url);
-      if (TALER_EC_NONE != ec)
-        GNUNET_asprintf (emsg,
-                         "Payto URL `%s' rejected by plugin\n",
-                         payto_url);
-      return ec;
-    }
-  }
-  GNUNET_asprintf (emsg,
-                   "Wire format type `%s' is not supported by this exchange\n",
-                   method);
-  GNUNET_free (method);
-  return TALER_EC_DEPOSIT_INVALID_WIRE_FORMAT_TYPE_UNSUPPORTED;
-}
-
-
-/**
  * Obtain JSON response for /wire
  *
  * @return JSON array with the supported validation methods, NULL on error
diff --git a/src/exchange/taler-exchange-wirewatch.c b/src/exchange/taler-exchange-wirewatch.c
index 21f62cd82..091f4ba20 100644
--- a/src/exchange/taler-exchange-wirewatch.c
+++ b/src/exchange/taler-exchange-wirewatch.c
@@ -27,6 +27,7 @@
 #include "taler_exchangedb_lib.h"
 #include "taler_exchangedb_plugin.h"
 #include "taler_json_lib.h"
+#include "taler_bank_service.h"
 #include "taler_wire_lib.h"
 
 /**
@@ -37,23 +38,6 @@
 
 
 /**
- * Closure for #reject_cb().
- */
-struct RejectContext
-{
-  /**
-   * Wire transfer subject that was illformed.
-   */
-  char *wtid_s;
-
-  /**
-   * Database session that encountered the problem.
-   */
-  struct TALER_EXCHANGEDB_Session *session;
-};
-
-
-/**
  * Information we keep for each supported account.
  */
 struct WireAccount
@@ -69,14 +53,19 @@ struct WireAccount
   struct WireAccount *prev;
 
   /**
-   * Handle to the plugin.
+   * Name of the section that configures this account.
    */
-  struct TALER_WIRE_Plugin *wire_plugin;
+  char *section_name;
 
   /**
-   * Name of the section that configures this account.
+   * Account information.
    */
-  char *section_name;
+  struct TALER_Account account;
+
+  /**
+   * Authentication data.
+   */
+  struct TALER_BANK_AuthenticationData auth;
 
   /**
    * Are we running from scratch and should re-process all transactions
@@ -108,6 +97,16 @@ static struct WireAccount *wa_tail;
 static struct WireAccount *wa_pos;
 
 /**
+ * Handle to the context for interacting with the bank.
+ */
+static struct GNUNET_CURL_Context *ctx;
+
+/**
+ * Scheduler context for running the @e ctx.
+ */
+static struct GNUNET_CURL_RescheduleContext *rc;
+
+/**
  * Which currency is used by this exchange?
  */
 static char *exchange_currency_string;
@@ -132,23 +131,13 @@ static int global_ret;
  * Encoded offset in the wire transfer list from where
  * to start the next query with the bank.
  */
-static void *last_row_off;
-
-/**
- * Number of bytes in #last_row_off.
- */
-static size_t last_row_off_size;
+static uint64_t last_row_off;
 
 /**
  * Latest row offset seen in this transaction, becomes
  * the new #last_row_off upon commit.
  */
-static void *latest_row_off;
-
-/**
- * Number of bytes in #latest_row_off.
- */
-static size_t latest_row_off_size;
+static uint64_t latest_row_off;
 
 /**
  * Should we delay the next request to the wire plugin a bit?
@@ -183,12 +172,7 @@ static struct GNUNET_SCHEDULER_Task *task;
 /**
  * Active request for history.
  */
-static struct TALER_WIRE_HistoryHandle *hh;
-
-/**
- * Active request to reject a wire transfer.
- */
-static struct TALER_WIRE_RejectHandle *rt;
+static struct TALER_BANK_CreditHistoryHandle *hh;
 
 
 /**
@@ -202,6 +186,16 @@ shutdown_task (void *cls)
   struct WireAccount *wa;
 
   (void) cls;
+  if (NULL != ctx)
+  {
+    GNUNET_CURL_fini (ctx);
+    ctx = NULL;
+  }
+  if (NULL != rc)
+  {
+    GNUNET_CURL_gnunet_rc_destroy (rc);
+    rc = NULL;
+  }
   if (NULL != task)
   {
     GNUNET_SCHEDULER_cancel (task);
@@ -209,20 +203,9 @@ shutdown_task (void *cls)
   }
   if (NULL != hh)
   {
-    wa_pos->wire_plugin->get_history_cancel (wa_pos->wire_plugin->cls,
-                                             hh);
+    TALER_BANK_credit_history_cancel (hh);
     hh = NULL;
   }
-  if (NULL != rt)
-  {
-    char *wtid_s;
-
-    wtid_s = wa_pos->wire_plugin->reject_transfer_cancel (
-      wa_pos->wire_plugin->cls,
-      rt);
-    rt = NULL;
-    GNUNET_free (wtid_s);
-  }
   TALER_EXCHANGEDB_plugin_unload (db_plugin);
   db_plugin = NULL;
   while (NULL != (wa = wa_head))
@@ -230,14 +213,13 @@ shutdown_task (void *cls)
     GNUNET_CONTAINER_DLL_remove (wa_head,
                                  wa_tail,
                                  wa);
-    TALER_WIRE_plugin_unload (wa->wire_plugin);
+    TALER_WIRE_account_free (&wa->account);
+    TALER_BANK_auth_free (&wa->auth);
     GNUNET_free (wa->section_name);
     GNUNET_free (wa);
   }
   wa_pos = NULL;
-  GNUNET_free_non_null (last_row_off);
-  last_row_off = NULL;
-  last_row_off_size = 0;
+  last_row_off = 0;
 }
 
 
@@ -259,13 +241,26 @@ add_account_cb (void *cls,
     return; /* not enabled for us, skip */
   wa = GNUNET_new (struct WireAccount);
   wa->reset_mode = reset_mode;
-  wa->wire_plugin = TALER_WIRE_plugin_load (cfg,
-                                            ai->plugin_name);
-  if (NULL == wa->wire_plugin)
+  if (GNUNET_OK !=
+      TALER_BANK_auth_parse_cfg (cfg,
+                                 ai->section_name,
+                                 &wa->auth))
   {
     GNUNET_log (GNUNET_ERROR_TYPE_MESSAGE,
-                "Failed to load wire plugin for `%s'\n",
-                ai->plugin_name);
+                "Failed to load account `%s'\n",
+                ai->section_name);
+    GNUNET_free (wa);
+    return;
+  }
+  if (GNUNET_OK !=
+      TALER_BANK_account_parse_cfg (cfg,
+                                    ai->section_name,
+                                    &wa->account))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_MESSAGE,
+                "Failed to load account `%s'\n",
+                ai->section_name);
+    TALER_BANK_auth_free (&wa->auth);
     GNUNET_free (wa);
     return;
   }
@@ -336,70 +331,28 @@ find_transfers (void *cls);
 
 
 /**
- * Function called upon completion of the rejection of a wire transfer.
- *
- * @param cls closure with the `struct RejectContext`
- * @param ec error code for the operation
- */
-static void
-reject_cb (void *cls,
-           enum TALER_ErrorCode ec)
-{
-  struct RejectContext *rtc = cls;
-  enum GNUNET_DB_QueryStatus qs;
-
-  rt = NULL;
-  if (TALER_EC_NONE != ec)
-  {
-    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                "Failed to wire back transfer `%s': %d\n",
-                rtc->wtid_s,
-                ec);
-    GNUNET_free (rtc->wtid_s);
-    db_plugin->rollback (db_plugin->cls,
-                         rtc->session);
-    GNUNET_free (rtc);
-    GNUNET_SCHEDULER_shutdown ();
-    return;
-  }
-  GNUNET_free (rtc->wtid_s);
-  qs = db_plugin->commit (db_plugin->cls,
-                          rtc->session);
-  GNUNET_break (0 <= qs);
-  GNUNET_free (rtc);
-  task = GNUNET_SCHEDULER_add_now (&find_transfers,
-                                   NULL);
-}
-
-
-/**
  * Callbacks of this type are used to serve the result of asking
  * the bank for the transaction history.
  *
  * @param cls closure with the `struct TALER_EXCHANGEDB_Session *`
  * @param ec taler error code
- * @param dir direction of the transfer
- * @param row_off identification of the position at which we are querying
- * @param row_off_size number of bytes in @a row_off
+ * @param serial_id identification of the position at which we are querying
  * @param details details about the wire transfer
+ * @param json raw JSON response
  * @return #GNUNET_OK to continue, #GNUNET_SYSERR to abort iteration
  */
 static int
 history_cb (void *cls,
+            unsigned int http_status,
             enum TALER_ErrorCode ec,
-            enum TALER_BANK_Direction dir,
-            const void *row_off,
-            size_t row_off_size,
-            const struct TALER_WIRE_TransferDetails *details)
+            uint64_t serial_id,
+            const struct TALER_BANK_CreditDetails *details,
+            const json_t *json)
 {
   struct TALER_EXCHANGEDB_Session *session = cls;
   enum GNUNET_DB_QueryStatus qs;
-  struct TALER_ReservePublicKeyP reserve_pub;
 
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "Got history callback, direction %u!\n",
-              (unsigned int) dir);
-  if (TALER_BANK_DIRECTION_NONE == dir)
+  if (NULL == details)
   {
     hh = NULL;
     if (TALER_EC_NONE != ec)
@@ -428,11 +381,8 @@ history_cb (void *cls,
     if (0 < qs)
     {
       /* transaction success, update #last_row_off */
-      GNUNET_free_non_null (last_row_off);
       last_row_off = latest_row_off;
-      last_row_off_size = latest_row_off_size;
-      latest_row_off = NULL;
-      latest_row_off_size = 0;
+      latest_row_off = 0;
 
       /* if successful at limit, try increasing transaction batch size (AIMD) */
       if (current_batch_size == batch_size)
@@ -462,49 +412,10 @@ history_cb (void *cls,
                                     NULL);
     return GNUNET_OK; /* will be ignored anyway */
   }
-  if (NULL != details->wtid_s)
-  {
-    struct RejectContext *rtc;
-
-    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                "Wire transfer over %s has invalid subject `%s', sending it back!\n",
-                TALER_amount2s (&details->amount),
-                details->wtid_s);
-    GNUNET_break (0 != row_off_size);
-    if (latest_row_off_size != row_off_size)
-    {
-      GNUNET_free_non_null (latest_row_off);
-      latest_row_off = GNUNET_malloc (row_off_size);
-      latest_row_off_size = row_off_size;
-    }
-    memcpy (latest_row_off,
-            row_off,
-            row_off_size);
-    rtc = GNUNET_new (struct RejectContext);
-    rtc->session = session;
-    rtc->wtid_s = GNUNET_strdup (details->wtid_s);
-    rt = wa_pos->wire_plugin->reject_transfer (wa_pos->wire_plugin->cls,
-                                               wa_pos->section_name,
-                                               row_off,
-                                               row_off_size,
-                                               &reject_cb,
-                                               rtc);
-    if (NULL == rt)
-    {
-      GNUNET_break (0);
-      db_plugin->rollback (db_plugin->cls,
-                           session);
-      GNUNET_assert (NULL == task);
-      task = GNUNET_SCHEDULER_add_now (&find_transfers,
-                                       NULL);
-    }
-    return GNUNET_SYSERR; /* will continue later... */
-  }
-
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
               "Adding wire transfer over %s with (hashed) subject `%s'\n",
               TALER_amount2s (&details->amount),
-              TALER_B2S (&details->wtid));
+              TALER_B2S (&details->reserve_pub));
 
   /**
    * Debug block.
@@ -515,8 +426,8 @@ history_cb (void *cls,
     char wtid_s[PUBSIZE];
 
     GNUNET_break
-      (NULL != GNUNET_STRINGS_data_to_string (&details->wtid,
-                                              sizeof (details->wtid),
+      (NULL != GNUNET_STRINGS_data_to_string (&details->reserve_pub,
+                                              sizeof (details->reserve_pub),
                                               &wtid_s[0],
                                               PUBSIZE));
     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
@@ -525,20 +436,14 @@ history_cb (void *cls,
   }
 
   current_batch_size++;
-  /* Wire transfer identifier == reserve public key */
-  GNUNET_assert (sizeof (reserve_pub) == sizeof (details->wtid));
-  memcpy (&reserve_pub,
-          &details->wtid,
-          sizeof (reserve_pub));
   qs = db_plugin->reserves_in_insert (db_plugin->cls,
                                       session,
-                                      &reserve_pub,
+                                      &details->reserve_pub,
                                       &details->amount,
                                       details->execution_date,
                                       details->account_url,
                                       wa_pos->section_name,
-                                      row_off,
-                                      row_off_size);
+                                      serial_id);
   if (GNUNET_DB_STATUS_HARD_ERROR == qs)
   {
     GNUNET_break (0);
@@ -560,15 +465,7 @@ history_cb (void *cls,
     return GNUNET_SYSERR;
   }
 
-  if (latest_row_off_size != row_off_size)
-  {
-    GNUNET_free_non_null (latest_row_off);
-    latest_row_off = GNUNET_malloc (row_off_size);
-    latest_row_off_size = row_off_size;
-  }
-  memcpy (latest_row_off,
-          row_off,
-          row_off_size);
+  latest_row_off = serial_id;
   return GNUNET_OK;
 }
 
@@ -615,8 +512,7 @@ find_transfers (void *cls)
     qs = db_plugin->get_latest_reserve_in_reference (db_plugin->cls,
                                                      session,
                                                      wa_pos->section_name,
-                                                     &last_row_off,
-                                                     &last_row_off_size);
+                                                     &last_row_off);
     if (GNUNET_DB_STATUS_HARD_ERROR == qs)
     {
       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
@@ -638,20 +534,17 @@ find_transfers (void *cls)
     }
   }
   wa_pos->reset_mode = GNUNET_NO;
-  GNUNET_assert ( (NULL == last_row_off) ||
-                  ( (NULL != last_row_off) &&
-                    (0 != last_row_off_size) ) );
   delay = GNUNET_YES;
   current_batch_size = 0;
 
-  hh = wa_pos->wire_plugin->get_history (wa_pos->wire_plugin->cls,
-                                         wa_pos->section_name,
-                                         TALER_BANK_DIRECTION_CREDIT,
-                                         last_row_off,
-                                         last_row_off_size,
-                                         batch_size,
-                                         &history_cb,
-                                         session);
+  hh = TALER_BANK_credit_history (ctx,
+                                  wa_pos->account.details.x_taler_bank.
+                                  account_base_url,
+                                  &wa_pos->auth,
+                                  last_row_off,
+                                  batch_size,
+                                  &history_cb,
+                                  session);
   if (NULL == hh)
   {
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
@@ -695,6 +588,14 @@ run (void *cls,
                                    NULL);
   GNUNET_SCHEDULER_add_shutdown (&shutdown_task,
                                  cls);
+  ctx = GNUNET_CURL_init (&GNUNET_CURL_gnunet_scheduler_reschedule,
+                          &rc);
+  rc = GNUNET_CURL_gnunet_rc_create (ctx);
+  if (NULL == ctx)
+  {
+    GNUNET_break (0);
+    return;
+  }
 }