add logic to check timestamp, revise history balance calculation logic in client

contrib/gana

@@ -1 +1 @@
-Subproject commit 4cfefdf374de55fe9be3f0f039c7a13f496ab970
+Subproject commit 25eb78f2d0e20a137020dd0ab1c6474123843dbe

src/exchange/taler-exchange-httpd_reserves_history.c

@@ -31,6 +31,14 @@
 #include "taler-exchange-httpd_responses.h"
 
 
+/**
+ * How far do we allow a client's time to be off when
+ * checking the request timestamp?
+ */
+#define TIMESTAMP_TOLERANCE \
+  GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
+
+
 /**
  * Closure for #reserve_history_transaction.
  */
@@ -121,8 +129,7 @@ reserve_history_transaction (void *cls,
   struct ReserveHistoryContext *rsc = cls;
   enum GNUNET_DB_QueryStatus qs;
 
-  // FIXME: first deduct rsc->gf->fees.history from balance!
+  // FIXME: first deduct rsc->gf->fees.history from reserve balance (and persist the signature justifying this)
-  // FIXME: pass rsc.gf->history_expiration?
   qs = TEH_plugin->get_reserve_history (TEH_plugin->cls,
                                         rsc->reserve_pub,
                                         &rsc->balance,
@@ -175,13 +182,21 @@ TEH_handler_reserves_history (struct TEH_RequestContext *rc,
     }
   }
   now = GNUNET_TIME_timestamp_get ();
-  /* FIXME: check that 'timestamp' is close to 'now' */
+  if (! GNUNET_TIME_absolute_approx_eq (now.abs_time,
-
+                                        rsc.timestamp.abs_time,
+                                        TIMESTAMP_TOLERANCE))
+  {
+    GNUNET_break_op (0);
+    return TALER_MHD_reply_with_error (rc->connection,
+                                       MHD_HTTP_BAD_REQUEST,
+                                       TALER_EC_EXCHANGE_GENERIC_CLOCK_SKEW,
+                                       NULL);
+  }
   rsc.gf = TEH_keys_global_fee_by_time (TEH_keys_get_state (),
                                         rsc.timestamp);
   if (NULL == rsc.gf)
   {
-    GNUNET_break_op (0);
+    GNUNET_break (0);
     return TALER_MHD_reply_with_error (rc->connection,
                                        MHD_HTTP_INTERNAL_SERVER_ERROR,
                                        TALER_EC_EXCHANGE_GENERIC_BAD_CONFIGURATION,

src/exchange/taler-exchange-httpd_reserves_status.c

@@ -30,6 +30,13 @@
 #include "taler-exchange-httpd_reserves_status.h"
 #include "taler-exchange-httpd_responses.h"
 
+/**
+ * How far do we allow a client's time to be off when
+ * checking the request timestamp?
+ */
+#define TIMESTAMP_TOLERANCE \
+  GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
+
 
 /**
  * Closure for #reserve_status_transaction.
@@ -140,6 +147,7 @@ TEH_handler_reserves_status (struct TEH_RequestContext *rc,
                                  &reserve_sig),
     GNUNET_JSON_spec_end ()
   };
+  struct GNUNET_TIME_Timestamp now;
 
   rsc.reserve_pub = reserve_pub;
   {
@@ -159,6 +167,17 @@ TEH_handler_reserves_status (struct TEH_RequestContext *rc,
       return MHD_YES; /* failure */
     }
   }
+  now = GNUNET_TIME_timestamp_get ();
+  if (! GNUNET_TIME_absolute_approx_eq (now.abs_time,
+                                        timestamp.abs_time,
+                                        TIMESTAMP_TOLERANCE))
+  {
+    GNUNET_break_op (0);
+    return TALER_MHD_reply_with_error (rc->connection,
+                                       MHD_HTTP_BAD_REQUEST,
+                                       TALER_EC_EXCHANGE_GENERIC_CLOCK_SKEW,
+                                       NULL);
+  }
   if (GNUNET_OK !=
       TALER_wallet_reserve_status_verify (timestamp,
                                           reserve_pub,

src/exchangedb/plugin_exchangedb_postgres.c

@@ -5595,6 +5595,7 @@ postgres_get_reserve_status (void *cls,
     GNUNET_PQ_query_param_end
   };
 
+  /* FIXME: actually implement reserve history truncation logic! */
   rhc.reserve_pub = reserve_pub;
   rhc.rh = NULL;
   rhc.rh_tail = NULL;

src/include/taler_exchange_service.h

@@ -1583,10 +1583,21 @@ struct TALER_EXCHANGE_ReserveStatus
     {
 
       /**
-       * Reserve balance.
+       * Current reserve balance.  May not be the difference between
+       * @e total_in and @e total_out because the @e may be truncated.
        */
       struct TALER_Amount balance;
 
+      /**
+       * Total of all inbound transactions in @e history.
+       */
+      struct TALER_Amount total_in;
+
+      /**
+       * Total of all outbound transactions in @e history.
+       */
+      struct TALER_Amount total_out;
+
       /**
        * Reserve history.
        */
@@ -1687,10 +1698,22 @@ struct TALER_EXCHANGE_ReserveHistory
     {
 
       /**
-       * Reserve balance.
+       * Reserve balance. May not be the difference between
+       * @e total_in and @e total_out because the @e may be truncated
+       * due to expiration.
        */
       struct TALER_Amount balance;
 
+      /**
+       * Total of all inbound transactions in @e history.
+       */
+      struct TALER_Amount total_in;
+
+      /**
+       * Total of all outbound transactions in @e history.
+       */
+      struct TALER_Amount total_out;
+
       /**
        * Reserve history.
        */
@@ -2685,7 +2708,8 @@ TALER_EXCHANGE_verify_coin_history (
  * @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[out] total_in set to value of credits to reserve
+ * @param[out] total_out set to value of debits from reserve
  * @param history_length number of entries in @a history
  * @param[out] rhistory array of length @a history_length, set to the
  *             parsed history entries
@@ -2699,7 +2723,8 @@ TALER_EXCHANGE_parse_reserve_history (
   const json_t *history,
   const struct TALER_ReservePublicKeyP *reserve_pub,
   const char *currency,
-  struct TALER_Amount *balance,
+  struct TALER_Amount *total_in,
+  struct TALER_Amount *total_out,
   unsigned int history_length,
   struct TALER_EXCHANGE_ReserveHistoryEntry *rhistory);
 

src/lib/exchange_api_common.c

@@ -32,21 +32,20 @@ TALER_EXCHANGE_parse_reserve_history (
   const json_t *history,
   const struct TALER_ReservePublicKeyP *reserve_pub,
   const char *currency,
-  struct TALER_Amount *balance,
+  struct TALER_Amount *total_in,
+  struct TALER_Amount *total_out,
   unsigned int history_length,
   struct TALER_EXCHANGE_ReserveHistoryEntry *rhistory)
 {
   struct GNUNET_HashCode uuid[history_length];
   unsigned int uuid_off;
-  struct TALER_Amount total_in;
-  struct TALER_Amount total_out;
 
   GNUNET_assert (GNUNET_OK ==
                  TALER_amount_set_zero (currency,
-                                        &total_in));
+                                        total_in));
   GNUNET_assert (GNUNET_OK ==
                  TALER_amount_set_zero (currency,
-                                        &total_out));
+                                        total_out));
   uuid_off = 0;
   for (unsigned int off = 0; off<history_length; off++)
   {
@@ -76,7 +75,7 @@ TALER_EXCHANGE_parse_reserve_history (
     rhistory[off].amount = amount;
     if (GNUNET_YES !=
         TALER_amount_cmp_currency (&amount,
-                                   &total_in))
+                                   total_in))
     {
       GNUNET_break_op (0);
       return GNUNET_SYSERR;
@@ -99,8 +98,8 @@ TALER_EXCHANGE_parse_reserve_history (
 
       rh->type = TALER_EXCHANGE_RTT_CREDIT;
       if (0 >
-          TALER_amount_add (&total_in,
+          TALER_amount_add (total_in,
-                            &total_in,
+                            total_in,
                             &amount))
       {
         /* overflow in history already!? inconceivable! Bad exchange! */
@@ -206,8 +205,8 @@ TALER_EXCHANGE_parse_reserve_history (
       uuid_off++;
 
       if (0 >
-          TALER_amount_add (&total_out,
+          TALER_amount_add (total_out,
-                            &total_out,
+                            total_out,
                             &amount))
       {
         /* overflow in history already!? inconceivable! Bad exchange! */
@@ -274,8 +273,8 @@ TALER_EXCHANGE_parse_reserve_history (
         return GNUNET_SYSERR;
       }
       if (0 >
-          TALER_amount_add (&total_in,
+          TALER_amount_add (total_in,
-                            &total_in,
+                            total_in,
                             &rh->amount))
       {
         /* overflow in history already!? inconceivable! Bad exchange! */
@@ -349,8 +348,8 @@ TALER_EXCHANGE_parse_reserve_history (
         return GNUNET_SYSERR;
       }
       if (0 >
-          TALER_amount_add (&total_out,
+          TALER_amount_add (total_out,
-                            &total_out,
+                            total_out,
                             &rh->amount))
       {
         /* overflow in history already!? inconceivable! Bad exchange! */
@@ -366,23 +365,6 @@ TALER_EXCHANGE_parse_reserve_history (
       return GNUNET_SYSERR;
     }
   }
-
-  /* check balance = total_in - total_out < withdraw-amount */
-  if (NULL != balance)
-  {
-    /* if balance is NULL, we may have a partial history
-       in which case the subtraction may fail, so we do
-       not even check that invariant in this case. */
-    if (0 >
-        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;
 }
 

src/lib/exchange_api_reserves_history.c

@@ -91,7 +91,6 @@ handle_reserves_history_ok (struct TALER_EXCHANGE_ReservesHistoryHandle *rsh,
 {
   json_t *history;
   unsigned int len;
-  struct TALER_Amount history_balance;
   struct TALER_EXCHANGE_ReserveHistory rs = {
     .hr.reply = j,
     .hr.http_status = MHD_HTTP_OK
@@ -123,15 +122,13 @@ handle_reserves_history_ok (struct TALER_EXCHANGE_ReservesHistoryHandle *rsh,
 
     rhistory = GNUNET_new_array (len,
                                  struct TALER_EXCHANGE_ReserveHistoryEntry);
-    // FIXME: even this history could be partial
-    // (if the reserve is too old!); update API
-    // and return incoming & outgoing totals separately?
     if (GNUNET_OK !=
         TALER_EXCHANGE_parse_reserve_history (rsh->exchange,
                                               history,
                                               &rsh->reserve_pub,
                                               rs.details.ok.balance.currency,
-                                              &history_balance,
+                                              &rs.details.ok.total_in,
+                                              &rs.details.ok.total_out,
                                               len,
                                               rhistory))
     {

src/lib/exchange_api_reserves_status.c

@@ -127,7 +127,8 @@ handle_reserves_status_ok (struct TALER_EXCHANGE_ReservesStatusHandle *rsh,
                                               history,
                                               &rsh->reserve_pub,
                                               rs.details.ok.balance.currency,
-                                              NULL,
+                                              &rs.details.ok.total_in,
+                                              &rs.details.ok.total_out,
                                               len,
                                               rhistory))
     {

src/lib/exchange_api_withdraw2.c

@@ -148,7 +148,8 @@ reserve_withdraw_payment_required (
   const json_t *json)
 {
   struct TALER_Amount balance;
-  struct TALER_Amount balance_from_history;
+  struct TALER_Amount total_in_from_history;
+  struct TALER_Amount total_out_from_history;
   json_t *history;
   size_t len;
   struct GNUNET_JSON_Specification spec[] = {
@@ -197,7 +198,8 @@ reserve_withdraw_payment_required (
                                               history,
                                               &wh->reserve_pub,
                                               balance.currency,
-                                              &balance_from_history,
+                                              &total_in_from_history,
+                                              &total_out_from_history,
                                               len,
                                               rhistory))
     {
@@ -210,14 +212,6 @@ reserve_withdraw_payment_required (
                                          len);
   }
 
-  if (0 !=
-      TALER_amount_cmp (&balance_from_history,
-                        &balance))
-  {
-    /* exchange cannot add up balances!? */
-    GNUNET_break_op (0);
-    return GNUNET_SYSERR;
-  }
   /* Check that funds were really insufficient */
   if (0 >= TALER_amount_cmp (&wh->requested_amount,
                              &balance))