src/auditor/taler-helper-auditor-coins.c

@@ -1896,7 +1896,7 @@ refund_cb (void *cls,
  * @param coin_blind blinding factor used to blind the coin
  * @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
  */
-static enum GNUNET_GenericReturnValue
+static int
 check_recoup (struct CoinContext *cc,
               const char *operation,
               uint64_t rowid,
@@ -1962,6 +1962,7 @@ check_recoup (struct CoinContext *cc,
   if (GNUNET_OK !=
       TALER_wallet_recoup_verify (&coin->denom_pub_hash,
                                   coin_blind,
+                                  amount,
                                   &coin->coin_pub,
                                   coin_sig))
   {
@@ -2083,7 +2084,7 @@ recoup_cb (void *cls,
  * @param coin_blind blinding factor used to blind the coin
  * @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
  */
-static enum GNUNET_GenericReturnValue
+static int
 recoup_refresh_cb (void *cls,
                    uint64_t rowid,
                    struct GNUNET_TIME_Timestamp timestamp,

src/auditor/taler-helper-auditor-reserves.c

@@ -714,6 +714,7 @@ handle_recoup_by_reserve (
   if (GNUNET_OK !=
       TALER_wallet_recoup_verify (&coin->denom_pub_hash,
                                   coin_blind,
+                                  amount,
                                   &coin->coin_pub,
                                   coin_sig))
   {

src/exchange/taler-exchange-httpd_recoup-refresh.c

@@ -62,6 +62,11 @@ struct RecoupContext
    */
   const struct TALER_CoinSpendSignatureP *coin_sig;
 
+  /**
+   * The amount requested to be recouped.
+   */
+  const struct TALER_Amount *requested_amount;
+
   /**
    * Unique ID of the coin in the known_coins table.
    */
@@ -113,6 +118,7 @@ recoup_refresh_transaction (void *cls,
   qs = TEH_plugin->do_recoup_refresh (TEH_plugin->cls,
                                       &pc->old_coin_pub,
                                       pc->rrc_serial,
+                                      pc->requested_amount,
                                       pc->coin_bks,
                                       &pc->coin->coin_pub,
                                       pc->known_coin_id,
@@ -164,6 +170,7 @@ recoup_refresh_transaction (void *cls,
  * @param coin information about the coin
  * @param coin_bks blinding data of the coin (to be checked)
  * @param coin_sig signature of the coin
+ * @param requested_amount requested amount to be recouped
  * @return MHD result code
  */
 static MHD_RESULT
@@ -171,7 +178,8 @@ verify_and_execute_recoup_refresh (
   struct MHD_Connection *connection,
   const struct TALER_CoinPublicInfo *coin,
   const union TALER_DenominationBlindingKeyP *coin_bks,
-  const struct TALER_CoinSpendSignatureP *coin_sig)
+  const struct TALER_CoinSpendSignatureP *coin_sig,
+  const struct TALER_Amount *requested_amount)
 {
   struct RecoupContext pc;
   const struct TEH_DenominationKey *dk;
@@ -229,6 +237,7 @@ verify_and_execute_recoup_refresh (
   if (GNUNET_OK !=
       TALER_wallet_recoup_refresh_verify (&coin->denom_pub_hash,
                                           coin_bks,
+                                          requested_amount,
                                           &coin->coin_pub,
                                           coin_sig))
   {
@@ -270,6 +279,7 @@ verify_and_execute_recoup_refresh (
   pc.coin_sig = coin_sig;
   pc.coin_bks = coin_bks;
   pc.coin = coin;
+  pc.requested_amount = requested_amount;
 
   {
     MHD_RESULT mhd_ret = MHD_NO;
@@ -357,6 +367,7 @@ TEH_handler_recoup_refresh (struct MHD_Connection *connection,
   struct TALER_CoinPublicInfo coin;
   union TALER_DenominationBlindingKeyP coin_bks;
   struct TALER_CoinSpendSignatureP coin_sig;
+  struct TALER_Amount amount;
   struct GNUNET_JSON_Specification spec[] = {
     GNUNET_JSON_spec_fixed_auto ("denom_pub_hash",
                                  &coin.denom_pub_hash),
@@ -366,6 +377,9 @@ TEH_handler_recoup_refresh (struct MHD_Connection *connection,
                                  &coin_bks),
     GNUNET_JSON_spec_fixed_auto ("coin_sig",
                                  &coin_sig),
+    TALER_JSON_spec_amount ("amount",
+                            TEH_currency,
+                            &amount),
     GNUNET_JSON_spec_end ()
   };
 
@@ -386,7 +400,8 @@ TEH_handler_recoup_refresh (struct MHD_Connection *connection,
     res = verify_and_execute_recoup_refresh (connection,
                                              &coin,
                                              &coin_bks,
-                                             &coin_sig);
+                                             &coin_sig,
+                                             &amount);
     GNUNET_JSON_parse_free (spec);
     return res;
   }

src/exchange/taler-exchange-httpd_recoup.c

@@ -65,6 +65,11 @@ struct RecoupContext
    */
   const struct TALER_CoinSpendSignatureP *coin_sig;
 
+  /**
+   * The amount requested to be recouped.
+   */
+  const struct TALER_Amount *requested_amount;
+
   /**
    * Unique ID of the withdraw operation in the reserves_out table.
    */
@@ -116,6 +121,7 @@ recoup_transaction (void *cls,
   qs = TEH_plugin->do_recoup (TEH_plugin->cls,
                               &pc->reserve_pub,
                               pc->reserve_out_serial_id,
+                              pc->requested_amount,
                               pc->coin_bks,
                               &pc->coin->coin_pub,
                               pc->known_coin_id,
@@ -167,6 +173,7 @@ recoup_transaction (void *cls,
  * @param coin information about the coin
  * @param coin_bks blinding data of the coin (to be checked)
  * @param coin_sig signature of the coin
+ * @param requested_amount requested amount to be recouped
  * @return MHD result code
  */
 static MHD_RESULT
@@ -174,7 +181,8 @@ verify_and_execute_recoup (
   struct MHD_Connection *connection,
   const struct TALER_CoinPublicInfo *coin,
   const union TALER_DenominationBlindingKeyP *coin_bks,
-  const struct TALER_CoinSpendSignatureP *coin_sig)
+  const struct TALER_CoinSpendSignatureP *coin_sig,
+  const struct TALER_Amount *requested_amount)
 {
   struct RecoupContext pc;
   const struct TEH_DenominationKey *dk;
@@ -231,6 +239,7 @@ verify_and_execute_recoup (
   if (GNUNET_OK !=
       TALER_wallet_recoup_verify (&coin->denom_pub_hash,
                                   coin_bks,
+                                  requested_amount,
                                   &coin->coin_pub,
                                   coin_sig))
   {
@@ -272,6 +281,7 @@ verify_and_execute_recoup (
   pc.coin_sig = coin_sig;
   pc.coin_bks = coin_bks;
   pc.coin = coin;
+  pc.requested_amount = requested_amount;
 
   {
     MHD_RESULT mhd_ret = MHD_NO;
@@ -359,6 +369,7 @@ TEH_handler_recoup (struct MHD_Connection *connection,
   struct TALER_CoinPublicInfo coin;
   union TALER_DenominationBlindingKeyP coin_bks;
   struct TALER_CoinSpendSignatureP coin_sig;
+  struct TALER_Amount amount;
   struct GNUNET_JSON_Specification spec[] = {
     GNUNET_JSON_spec_fixed_auto ("denom_pub_hash",
                                  &coin.denom_pub_hash),
@@ -368,6 +379,9 @@ TEH_handler_recoup (struct MHD_Connection *connection,
                                  &coin_bks),
     GNUNET_JSON_spec_fixed_auto ("coin_sig",
                                  &coin_sig),
+    TALER_JSON_spec_amount ("amount",
+                            TEH_currency,
+                            &amount),
     GNUNET_JSON_spec_end ()
   };
 
@@ -388,7 +402,8 @@ TEH_handler_recoup (struct MHD_Connection *connection,
     res = verify_and_execute_recoup (connection,
                                      &coin,
                                      &coin_bks,
-                                     &coin_sig);
+                                     &coin_sig,
+                                     &amount);
     GNUNET_JSON_parse_free (spec);
     return res;
   }

src/exchange/taler-exchange-httpd_withdraw.c

@@ -40,7 +40,6 @@
  *
  * @param connection connection to the client
  * @param ebalance expected balance based on our database
- * @param withdraw_amount amount that the client requested to withdraw
  * @param rh reserve history to return
  * @return MHD result code
  */
@@ -48,7 +47,6 @@ static MHD_RESULT
 reply_withdraw_insufficient_funds (
   struct MHD_Connection *connection,
   const struct TALER_Amount *ebalance,
-  const struct TALER_Amount *withdraw_amount,
   const struct TALER_EXCHANGEDB_ReserveHistory *rh)
 {
   json_t *json_history;
@@ -78,8 +76,6 @@ reply_withdraw_insufficient_funds (
     TALER_JSON_pack_ec (TALER_EC_EXCHANGE_WITHDRAW_INSUFFICIENT_FUNDS),
     TALER_JSON_pack_amount ("balance",
                             &balance),
-    TALER_JSON_pack_amount ("requested_amount",
-                            withdraw_amount),
     GNUNET_JSON_pack_array_steal ("history",
                                   json_history));
 }
@@ -178,7 +174,6 @@ withdraw_transaction (void *cls,
   {
     struct TALER_EXCHANGEDB_ReserveHistory *rh;
     struct TALER_Amount balance;
-    struct TALER_Amount requested_amount;
 
     TEH_plugin->rollback (TEH_plugin->cls);
     // FIXME: maybe start read-committed here?
@@ -209,11 +204,8 @@ withdraw_transaction (void *cls,
                                                "reserve history");
       return GNUNET_DB_STATUS_HARD_ERROR;
     }
-    TALER_amount_ntoh (&requested_amount,
-                       &wc->wsrd.amount_with_fee);
     *mhd_ret = reply_withdraw_insufficient_funds (connection,
                                                   &balance,
-                                                  &requested_amount,
                                                   rh);
     TEH_plugin->free_reserve_history (TEH_plugin->cls,
                                       rh);

src/exchangedb/exchange-0001.sql

@@ -918,7 +918,7 @@ END IF;
 -- Check reserve balance is sufficient.
 IF (reserve_val > amount_val)
 THEN
-  IF (reserve_frac >= amount_frac)
+  IF (reserve_frac > amount_frac)
   THEN
     reserve_val=reserve_val - amount_val;
     reserve_frac=reserve_frac - amount_frac;
@@ -1508,6 +1508,8 @@ END $$;
 CREATE OR REPLACE FUNCTION exchange_do_recoup_to_reserve(
   IN in_reserve_pub BYTEA,
   IN in_reserve_out_serial_id INT8,
+  IN in_amount_val INT8,
+  IN in_amount_frac INT4,
   IN in_coin_blind BYTEA,
   IN in_coin_pub BYTEA,
   IN in_known_coin_id INT8,
@@ -1521,71 +1523,76 @@ CREATE OR REPLACE FUNCTION exchange_do_recoup_to_reserve(
 LANGUAGE plpgsql
 AS $$
 DECLARE
-  tmp_val INT8; -- amount recouped
+  tmp_val INT8; -- previous amount recouped
 DECLARE
-  tmp_frac INT8; -- amount recouped
+  tmp_frac INT8; -- previous amount recouped
 BEGIN
 -- Shards: SELECT known_coins (by coin_pub)
 --         SELECT recoup (by known_coin_id)
---         UPDATE known_coins (by coin_pub)
 --         UPDATE reserves (by reserve_pub)
 --         INSERT recoup (by known_coin_id)
 
 out_internal_failure=FALSE;
 
-
+-- Check and update balance of the coin.
--- Check remaining balance of the coin.
+UPDATE known_coins
-SELECT
+  SET
-   remaining_frac
+    remaining_frac=remaining_frac-in_amount_frac
-  ,remaining_val
+       + CASE
- INTO
+         WHEN remaining_frac < in_amount_frac
-   tmp_frac
+         THEN 100000000
-  ,tmp_val
+         ELSE 0
-FROM known_coins
+         END,
-  WHERE coin_pub=in_coin_pub;
+    remaining_val=remaining_val-in_amount_val
+       - CASE
+         WHEN remaining_frac < in_amount_frac
+         THEN 1
+         ELSE 0
+         END
+  WHERE coin_pub=in_coin_pub
+    AND ( (remaining_val > in_amount_val) OR
+          ( (remaining_frac >= in_amount_frac) AND
+            (remaining_val >= in_amount_val) ) );
 
 IF NOT FOUND
 THEN
-  out_internal_failure=TRUE;
+  -- Check if we already recouped this coin before!
-  out_recoup_ok=FALSE;
-  RETURN;
-END IF;
-
-IF tmp_val + tmp_frac = 0
-THEN
-  -- Check for idempotency
   SELECT
-    recoup_timestamp
+       amount_val
+      ,amount_frac
+      ,recoup_timestamp
     INTO
-    out_recoup_timestamp
+       tmp_val
+      ,tmp_frac
+      ,out_recoup_timestamp
     FROM recoup
     WHERE known_coin_id=in_known_coin_id;
 
-  out_recoup_ok=FOUND;
+  IF FOUND
+  THEN
+    -- Idempotent request, all OK!
+    out_recoup_ok= (tmp_val = in_amount_val) AND
+                   (tmp_frac = in_amount_frac);
+    RETURN;
+  END IF;
+
+  out_recoup_ok=FALSE;
   RETURN;
 END IF;
 
 
--- Update balance of the coin.
-UPDATE known_coins
-  SET
-     remaining_frac=0
-    ,remaining_val=0
-  WHERE coin_pub=in_coin_pub;
-
-
 -- Credit the reserve and update reserve timers.
 UPDATE reserves
   SET
-    current_balance_frac=current_balance_frac+tmp_frac
+    current_balance_frac=current_balance_frac+in_amount_frac
        - CASE
-         WHEN current_balance_frac+tmp_frac >= 100000000
+         WHEN current_balance_frac+in_amount_frac >= 100000000
          THEN 100000000
          ELSE 0
          END,
-    current_balance_val=current_balance_val+tmp_val
+    current_balance_val=current_balance_val+in_amount_val
        + CASE
-         WHEN current_balance_frac+tmp_frac >= 100000000
+         WHEN current_balance_frac+in_amount_frac >= 100000000
          THEN 1
          ELSE 0
          END,
@@ -1597,7 +1604,7 @@ UPDATE reserves
 IF NOT FOUND
 THEN
   RAISE NOTICE 'failed to increase reserve balance from recoup';
-  out_recoup_ok=TRUE;
+  out_recoup_ok=FALSE;
   out_internal_failure=TRUE;
   RETURN;
 END IF;
@@ -1616,8 +1623,8 @@ VALUES
   (in_known_coin_id
   ,in_coin_sig
   ,in_coin_blind
-  ,tmp_val
+  ,in_amount_val
-  ,tmp_frac
+  ,in_amount_frac
   ,in_recoup_timestamp
   ,in_reserve_out_serial_id);
 
@@ -1638,6 +1645,8 @@ END $$;
 CREATE OR REPLACE FUNCTION exchange_do_recoup_to_coin(
   IN in_old_coin_pub BYTEA,
   IN in_rrc_serial INT8,
+  IN in_amount_val INT8,
+  IN in_amount_frac INT4,
   IN in_coin_blind BYTEA,
   IN in_coin_pub BYTEA,
   IN in_known_coin_id INT8,
@@ -1649,9 +1658,9 @@ CREATE OR REPLACE FUNCTION exchange_do_recoup_to_coin(
 LANGUAGE plpgsql
 AS $$
 DECLARE
-  tmp_val INT8; -- amount recouped
+  tmp_val INT8; -- previous amount recouped
 DECLARE
-  tmp_frac INT8; -- amount recouped
+  tmp_frac INT8; -- previous amount recouped
 BEGIN
 
 -- Shards: UPDATE known_coins (by coin_pub)
@@ -1662,57 +1671,66 @@ BEGIN
 
 out_internal_failure=FALSE;
 
-
+-- Check and update balance of the coin.
--- Check remaining balance of the coin.
+UPDATE known_coins
-SELECT
+  SET
-   remaining_frac
+    remaining_frac=remaining_frac-in_amount_frac
-  ,remaining_val
+       + CASE
- INTO
+         WHEN remaining_frac < in_amount_frac
-   tmp_frac
+         THEN 100000000
-  ,tmp_val
+         ELSE 0
-FROM known_coins
+         END,
-  WHERE coin_pub=in_coin_pub;
+    remaining_val=remaining_val-in_amount_val
+       - CASE
+         WHEN remaining_frac < in_amount_frac
+         THEN 1
+         ELSE 0
+         END
+  WHERE coin_pub=in_coin_pub
+    AND ( (remaining_val > in_amount_val) OR
+          ( (remaining_frac >= in_amount_frac) AND
+            (remaining_val >= in_amount_val) ) );
 
 IF NOT FOUND
 THEN
-  out_internal_failure=TRUE;
+  -- Check if we already recouped this coin before!
+  SELECT
+       amount_val
+      ,amount_frac
+      ,recoup_timestamp
+    INTO
+       tmp_val
+      ,tmp_frac
+      ,out_recoup_timestamp
+    FROM recoup_refresh
+    WHERE known_coin_id=in_known_coin_id;
+
+  IF FOUND
+  THEN
+    -- Idempotent request, all OK!
+    out_recoup_ok= (tmp_val = in_amount_val) AND
+                   (tmp_frac = in_amount_frac);
+    RETURN;
+  END IF;
+
+  -- Insufficient balance, not idempotent.
   out_recoup_ok=FALSE;
   RETURN;
 END IF;
 
-IF tmp_val + tmp_frac = 0
-THEN
-  -- Check for idempotency
-  SELECT
-      recoup_timestamp
-    INTO
-      out_recoup_timestamp
-    FROM recoup_refresh
-    WHERE known_coin_id=in_known_coin_id;
-  out_recoup_ok=FOUND;
-  RETURN;
-END IF;
-
--- Update balance of the coin.
-UPDATE known_coins
-  SET
-     remaining_frac=0
-    ,remaining_val=0
-  WHERE coin_pub=in_coin_pub;
-
 
 -- Credit the old coin.
 UPDATE known_coins
   SET
-    remaining_frac=remaining_frac+tmp_frac
+    remaining_frac=remaining_frac+in_amount_frac
        - CASE
-         WHEN remaining_frac+tmp_frac >= 100000000
+         WHEN remaining_frac+in_amount_frac >= 100000000
          THEN 100000000
          ELSE 0
          END,
-    remaining_val=remaining_val+tmp_val
+    remaining_val=remaining_val+in_amount_val
        + CASE
-         WHEN remaining_frac+tmp_frac >= 100000000
+         WHEN remaining_frac+in_amount_frac >= 100000000
          THEN 1
          ELSE 0
          END
@@ -1722,7 +1740,7 @@ UPDATE known_coins
 IF NOT FOUND
 THEN
   RAISE NOTICE 'failed to increase old coin balance from recoup';
-  out_recoup_ok=TRUE;
+  out_recoup_ok=FALSE;
   out_internal_failure=TRUE;
   RETURN;
 END IF;
@@ -1741,8 +1759,8 @@ VALUES
   (in_known_coin_id
   ,in_coin_sig
   ,in_coin_blind
-  ,tmp_val
+  ,in_amount_val
-  ,tmp_frac
+  ,in_amount_frac
   ,in_recoup_timestamp
   ,in_rrc_serial);
 

src/exchangedb/plugin_exchangedb_postgres.c

@@ -636,8 +636,8 @@ prepare_statements (struct PostgresClosure *pg)
       ",out_recoup_ok AS recoup_ok"
       ",out_internal_failure AS internal_failure"
       " FROM exchange_do_recoup_to_reserve"
-      " ($1,$2,$3,$4,$5,$6,$7,$8,$9);",
+      " ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11);",
-      9),
+      11),
     /* Used in #postgres_do_recoup_refresh() to recoup a coin to a zombie coin. */
     GNUNET_PQ_make_prepare (
       "call_recoup_refresh",
@@ -646,8 +646,8 @@ prepare_statements (struct PostgresClosure *pg)
       ",out_recoup_ok AS recoup_ok"
       ",out_internal_failure AS internal_failure"
       " FROM exchange_do_recoup_to_coin"
-      " ($1,$2,$3,$4,$5,$6,$7);",
+      " ($1,$2,$3,$4,$5,$6,$7,$8,$9);",
-      7),
+      9),
     /* Used in #postgres_get_withdraw_info() to
        locate the response for a /reserve/withdraw request
        using the hash of the blinded message.  Used to
@@ -4674,6 +4674,7 @@ postgres_do_refund (
  * @param cls the `struct PostgresClosure` with the plugin-specific state
  * @param reserve_pub public key of the reserve to credit
  * @param reserve_out_serial_id row in the reserves_out table justifying the recoup
+ * @param requested_amount the amount to be recouped
  * @param coin_bks coin blinding key secret to persist
  * @param coin_pub public key of the coin being recouped
  * @param known_coin_id row of the @a coin_pub in the known_coins table
@@ -4688,6 +4689,7 @@ postgres_do_recoup (
   void *cls,
   const struct TALER_ReservePublicKeyP *reserve_pub,
   uint64_t reserve_out_serial_id,
+  const struct TALER_Amount *requested_amount,
   const union TALER_DenominationBlindingKeyP *coin_bks,
   const struct TALER_CoinSpendPublicKeyP *coin_pub,
   uint64_t known_coin_id,
@@ -4704,6 +4706,7 @@ postgres_do_recoup (
   struct GNUNET_PQ_QueryParam params[] = {
     GNUNET_PQ_query_param_auto_from_type (reserve_pub),
     GNUNET_PQ_query_param_uint64 (&reserve_out_serial_id),
+    TALER_PQ_query_param_amount (requested_amount),
     GNUNET_PQ_query_param_auto_from_type (coin_bks),
     GNUNET_PQ_query_param_auto_from_type (coin_pub),
     GNUNET_PQ_query_param_uint64 (&known_coin_id),
@@ -4740,6 +4743,7 @@ postgres_do_recoup (
  * @param cls the `struct PostgresClosure` with the plugin-specific state
  * @param old_coin_pub public key of the old coin to credit
  * @param rrc_serial row in the refresh_revealed_coins table justifying the recoup-refresh
+ * @param requested_amount the amount to be recouped
  * @param coin_bks coin blinding key secret to persist
  * @param coin_pub public key of the coin being recouped
  * @param known_coin_id row of the @a coin_pub in the known_coins table
@@ -4754,6 +4758,7 @@ postgres_do_recoup_refresh (
   void *cls,
   const struct TALER_CoinSpendPublicKeyP *old_coin_pub,
   uint64_t rrc_serial,
+  const struct TALER_Amount *requested_amount,
   const union TALER_DenominationBlindingKeyP *coin_bks,
   const struct TALER_CoinSpendPublicKeyP *coin_pub,
   uint64_t known_coin_id,
@@ -4766,6 +4771,7 @@ postgres_do_recoup_refresh (
   struct GNUNET_PQ_QueryParam params[] = {
     GNUNET_PQ_query_param_auto_from_type (old_coin_pub),
     GNUNET_PQ_query_param_uint64 (&rrc_serial),
+    TALER_PQ_query_param_amount (requested_amount),
     GNUNET_PQ_query_param_auto_from_type (coin_bks),
     GNUNET_PQ_query_param_auto_from_type (coin_pub),
     GNUNET_PQ_query_param_uint64 (&known_coin_id),

src/exchangedb/test_exchangedb.c

@@ -1766,6 +1766,7 @@ run (void *cls)
             plugin->do_recoup_refresh (plugin->cls,
                                        &deposit.coin.coin_pub,
                                        rrc_serial,
+                                       &value,
                                        &coin_bks,
                                        &new_coin.coin_pub,
                                        new_known_coin_id,
@@ -1785,6 +1786,7 @@ run (void *cls)
     struct TALER_EXCHANGEDB_KycStatus kyc;
     bool recoup_ok;
     bool internal_failure;
+    struct TALER_Amount requested_amount;
     struct GNUNET_TIME_Timestamp recoup_timestamp
       = GNUNET_TIME_timestamp_get ();
 
@@ -1793,11 +1795,13 @@ run (void *cls)
             plugin->reserves_get (plugin->cls,
                                   &pre_reserve,
                                   &kyc));
+    requested_amount = value;
     FAILIF (! TALER_amount_is_zero (&pre_reserve.balance));
     FAILIF (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT !=
             plugin->do_recoup (plugin->cls,
                                &reserve_pub,
                                reserve_out_serial_id,
+                               &requested_amount,
                                &coin_blind,
                                &deposit.coin.coin_pub,
                                known_coin_id,

src/include/taler_crypto_lib.h

@@ -1839,6 +1839,7 @@ TALER_wallet_link_sign (const struct TALER_DenominationHash *h_denom_pub,
  *
  * @param h_denom_pub hash of the denomiantion public key of the coin
  * @param coin_bks blinding factor used when withdrawing the coin
+ * @param requested_amount amount that is left to be recouped
  * @param coin_pub coin key of the coin to be recouped
  * @param coin_sig resulting signature
  * @return #GNUNET_OK if the signature is valid
@@ -1847,6 +1848,7 @@ enum GNUNET_GenericReturnValue
 TALER_wallet_recoup_verify (
   const struct TALER_DenominationHash *h_denom_pub,
   const union TALER_DenominationBlindingKeyP *coin_bks,
+  const struct TALER_Amount *requested_amount,
   const struct TALER_CoinSpendPublicKeyP *coin_pub,
   const struct TALER_CoinSpendSignatureP *coin_sig);
 
@@ -1864,6 +1866,7 @@ void
 TALER_wallet_recoup_sign (
   const struct TALER_DenominationHash *h_denom_pub,
   const union TALER_DenominationBlindingKeyP *coin_bks,
+  const struct TALER_Amount *requested_amount,
   const struct TALER_CoinSpendPrivateKeyP *coin_priv,
   struct TALER_CoinSpendSignatureP *coin_sig);
 
@@ -1873,6 +1876,7 @@ TALER_wallet_recoup_sign (
  *
  * @param h_denom_pub hash of the denomiantion public key of the coin
  * @param coin_bks blinding factor used when withdrawing the coin
+ * @param requested_amount amount that is left to be recouped
  * @param coin_pub coin key of the coin to be recouped
  * @param coin_sig resulting signature
  * @return #GNUNET_OK if the signature is valid
@@ -1881,6 +1885,7 @@ enum GNUNET_GenericReturnValue
 TALER_wallet_recoup_refresh_verify (
   const struct TALER_DenominationHash *h_denom_pub,
   const union TALER_DenominationBlindingKeyP *coin_bks,
+  const struct TALER_Amount *requested_amount,
   const struct TALER_CoinSpendPublicKeyP *coin_pub,
   const struct TALER_CoinSpendSignatureP *coin_sig);
 
@@ -1898,6 +1903,7 @@ void
 TALER_wallet_recoup_refresh_sign (
   const struct TALER_DenominationHash *h_denom_pub,
   const union TALER_DenominationBlindingKeyP *coin_bks,
+  const struct TALER_Amount *requested_amount,
   const struct TALER_CoinSpendPrivateKeyP *coin_priv,
   struct TALER_CoinSpendSignatureP *coin_sig);
 

src/include/taler_exchange_service.h

@@ -2035,6 +2035,7 @@ typedef void
  * @param pk kind of coin to pay back
  * @param denom_sig signature over the coin by the exchange using @a pk
  * @param ps secret internals of the original planchet
+ * @param amount value remaining on the coin that is being recouped
  * @param recoup_cb the callback to call when the final result for this request is available
  * @param recoup_cb_cls closure for @a recoup_cb
  * @return NULL
@@ -2046,6 +2047,7 @@ TALER_EXCHANGE_recoup (struct TALER_EXCHANGE_Handle *exchange,
                        const struct TALER_EXCHANGE_DenomPublicKey *pk,
                        const struct TALER_DenominationSignature *denom_sig,
                        const struct TALER_PlanchetSecretsP *ps,
+                       const struct TALER_Amount *amount,
                        TALER_EXCHANGE_RecoupResultCallback recoup_cb,
                        void *recoup_cb_cls);
 
@@ -2095,6 +2097,7 @@ typedef void
  * @param pk kind of coin to pay back
  * @param denom_sig signature over the coin by the exchange using @a pk
  * @param ps secret internals of the original planchet
+ * @param amount value remaining on the coin that is being recouped
  * @param recoup_cb the callback to call when the final result for this request is available
  * @param recoup_cb_cls closure for @a recoup_cb
  * @return NULL
@@ -2107,6 +2110,7 @@ TALER_EXCHANGE_recoup_refresh (
   const struct TALER_EXCHANGE_DenomPublicKey *pk,
   const struct TALER_DenominationSignature *denom_sig,
   const struct TALER_PlanchetSecretsP *ps,
+  const struct TALER_Amount *amount,
   TALER_EXCHANGE_RecoupRefreshResultCallback recoup_cb,
   void *recoup_cb_cls);
 

src/include/taler_exchangedb_plugin.h

@@ -2596,6 +2596,7 @@ struct TALER_EXCHANGEDB_Plugin
    * @param cls the `struct PostgresClosure` with the plugin-specific state
    * @param reserve_pub public key of the reserve to credit
    * @param reserve_out_serial_id row in the reserves_out table justifying the recoup
+   * @param requested_amount the amount to be recouped
    * @param coin_bks coin blinding key secret to persist
    * @param coin_pub public key of the coin being recouped
    * @param known_coin_id row of the @a coin_pub in the known_coins table
@@ -2610,6 +2611,7 @@ struct TALER_EXCHANGEDB_Plugin
     void *cls,
     const struct TALER_ReservePublicKeyP *reserve_pub,
     uint64_t reserve_out_serial_id,
+    const struct TALER_Amount *requested_amount,
     const union TALER_DenominationBlindingKeyP *coin_bks,
     const struct TALER_CoinSpendPublicKeyP *coin_pub,
     uint64_t known_coin_id,
@@ -2626,6 +2628,7 @@ struct TALER_EXCHANGEDB_Plugin
    * @param cls the `struct PostgresClosure` with the plugin-specific state
    * @param old_coin_pub public key of the old coin to credit
    * @param rrc_serial row in the refresh_revealed_coins table justifying the recoup-refresh
+   * @param requested_amount the amount to be recouped
    * @param coin_bks coin blinding key secret to persist
    * @param coin_pub public key of the coin being recouped
    * @param known_coin_id row of the @a coin_pub in the known_coins table
@@ -2640,6 +2643,7 @@ struct TALER_EXCHANGEDB_Plugin
     void *cls,
     const struct TALER_CoinSpendPublicKeyP *old_coin_pub,
     uint64_t rrc_serial,
+    const struct TALER_Amount *requested_amount,
     const union TALER_DenominationBlindingKeyP *coin_bks,
     const struct TALER_CoinSpendPublicKeyP *coin_pub,
     uint64_t known_coin_id,

src/include/taler_signatures.h

@@ -1507,7 +1507,6 @@ struct TALER_RecoupRequestPS
 {
   /**
    * Purpose is #TALER_SIGNATURE_WALLET_COIN_RECOUP
-   * or #TALER_SIGNATURE_WALLET_COIN_RECOUP_REFRESH.
    */
   struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
 
@@ -1521,6 +1520,11 @@ struct TALER_RecoupRequestPS
    */
   union TALER_DenominationBlindingKeyP coin_blind;
 
+  /**
+   * How much of the coin's value will be recouped?
+   */
+  struct TALER_AmountNBO recoup_amount;
+
 };
 
 

src/lib/exchange_api_common.c

@@ -726,6 +726,7 @@ TALER_EXCHANGE_verify_coin_history (
       if (GNUNET_OK !=
           TALER_wallet_recoup_verify (h_denom_pub,
                                       &coin_bks,
+                                      &recoup_amount,
                                       coin_pub,
                                       &coin_sig))
       {
@@ -795,6 +796,7 @@ TALER_EXCHANGE_verify_coin_history (
       if (GNUNET_OK !=
           TALER_wallet_recoup_verify (h_denom_pub,
                                       &coin_bks,
+                                      &recoup_amount,
                                       coin_pub,
                                       &coin_sig))
       {

src/lib/exchange_api_recoup.c

@@ -285,6 +285,7 @@ TALER_EXCHANGE_recoup (struct TALER_EXCHANGE_Handle *exchange,
                        const struct TALER_EXCHANGE_DenomPublicKey *pk,
                        const struct TALER_DenominationSignature *denom_sig,
                        const struct TALER_PlanchetSecretsP *ps,
+                       const struct TALER_Amount *amount,
                        TALER_EXCHANGE_RecoupResultCallback recoup_cb,
                        void *recoup_cb_cls)
 {
@@ -305,6 +306,7 @@ TALER_EXCHANGE_recoup (struct TALER_EXCHANGE_Handle *exchange,
                         &h_denom_pub);
   TALER_wallet_recoup_sign (&h_denom_pub,
                             &ps->blinding_key,
+                            amount,
                             &ps->coin_priv,
                             &coin_sig);
   recoup_obj = GNUNET_JSON_PACK (
@@ -312,6 +314,8 @@ TALER_EXCHANGE_recoup (struct TALER_EXCHANGE_Handle *exchange,
                                 &h_denom_pub),
     TALER_JSON_pack_denom_sig ("denom_sig",
                                denom_sig),
+    TALER_JSON_pack_amount ("amount",
+                            amount),
     GNUNET_JSON_pack_data_auto ("coin_sig",
                                 &coin_sig),
     GNUNET_JSON_pack_data_auto ("coin_blind_key_secret",

src/lib/exchange_api_recoup_refresh.c

@@ -287,6 +287,7 @@ TALER_EXCHANGE_recoup_refresh (
   const struct TALER_EXCHANGE_DenomPublicKey *pk,
   const struct TALER_DenominationSignature *denom_sig,
   const struct TALER_PlanchetSecretsP *ps,
+  const struct TALER_Amount *amount,
   TALER_EXCHANGE_RecoupRefreshResultCallback recoup_cb,
   void *recoup_cb_cls)
 {
@@ -307,6 +308,7 @@ TALER_EXCHANGE_recoup_refresh (
                         &h_denom_pub);
   TALER_wallet_recoup_refresh_sign (&h_denom_pub,
                                     &ps->blinding_key,
+                                    amount,
                                     &ps->coin_priv,
                                     &coin_sig);
   recoup_obj = GNUNET_JSON_PACK (
@@ -314,6 +316,8 @@ TALER_EXCHANGE_recoup_refresh (
                                 &h_denom_pub),
     TALER_JSON_pack_denom_sig ("denom_sig",
                                denom_sig),
+    TALER_JSON_pack_amount ("amount",
+                            amount),
     GNUNET_JSON_pack_data_auto ("coin_sig",
                                 &coin_sig),
     GNUNET_JSON_pack_data_auto ("coin_blind_key_secret",

src/testing/testing_api_cmd_recoup.c

@@ -318,6 +318,7 @@ recoup_run (void *cls,
                                   denom_pub,
                                   coin_sig,
                                   &planchet,
+                                  &ps->reserve_history.amount,
                                   &recoup_cb,
                                   ps);
   GNUNET_assert (NULL != ps->ph);

src/testing/testing_api_cmd_recoup_refresh.c

@@ -309,6 +309,7 @@ recoup_refresh_run (void *cls,
                                           denom_pub,
                                           coin_sig,
                                           &planchet,
+                                          &ps->amount,
                                           recoup_refresh_cb,
                                           ps);
   GNUNET_assert (NULL != ps->ph);

src/util/wallet_signatures.c

@@ -157,6 +157,7 @@ enum GNUNET_GenericReturnValue
 TALER_wallet_recoup_verify (
   const struct TALER_DenominationHash *h_denom_pub,
   const union TALER_DenominationBlindingKeyP *coin_bks,
+  const struct TALER_Amount *requested_amount,
   const struct TALER_CoinSpendPublicKeyP *coin_pub,
   const struct TALER_CoinSpendSignatureP *coin_sig)
 {
@@ -167,6 +168,8 @@ TALER_wallet_recoup_verify (
     .coin_blind = *coin_bks
   };
 
+  TALER_amount_hton (&pr.recoup_amount,
+                     requested_amount);
   return GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_WALLET_COIN_RECOUP,
                                      &pr,
                                      &coin_sig->eddsa_signature,
@@ -178,6 +181,7 @@ void
 TALER_wallet_recoup_sign (
   const struct TALER_DenominationHash *h_denom_pub,
   const union TALER_DenominationBlindingKeyP *coin_bks,
+  const struct TALER_Amount *requested_amount,
   const struct TALER_CoinSpendPrivateKeyP *coin_priv,
   struct TALER_CoinSpendSignatureP *coin_sig)
 {
@@ -188,6 +192,8 @@ TALER_wallet_recoup_sign (
     .coin_blind = *coin_bks
   };
 
+  TALER_amount_hton (&pr.recoup_amount,
+                     requested_amount);
   GNUNET_CRYPTO_eddsa_sign (&coin_priv->eddsa_priv,
                             &pr,
                             &coin_sig->eddsa_signature);
@@ -198,6 +204,7 @@ enum GNUNET_GenericReturnValue
 TALER_wallet_recoup_refresh_verify (
   const struct TALER_DenominationHash *h_denom_pub,
   const union TALER_DenominationBlindingKeyP *coin_bks,
+  const struct TALER_Amount *requested_amount,
   const struct TALER_CoinSpendPublicKeyP *coin_pub,
   const struct TALER_CoinSpendSignatureP *coin_sig)
 {
@@ -208,6 +215,8 @@ TALER_wallet_recoup_refresh_verify (
     .coin_blind = *coin_bks
   };
 
+  TALER_amount_hton (&pr.recoup_amount,
+                     requested_amount);
   return GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_WALLET_COIN_RECOUP_REFRESH,
                                      &pr,
                                      &coin_sig->eddsa_signature,
@@ -219,6 +228,7 @@ void
 TALER_wallet_recoup_refresh_sign (
   const struct TALER_DenominationHash *h_denom_pub,
   const union TALER_DenominationBlindingKeyP *coin_bks,
+  const struct TALER_Amount *requested_amount,
   const struct TALER_CoinSpendPrivateKeyP *coin_priv,
   struct TALER_CoinSpendSignatureP *coin_sig)
 {
@@ -229,6 +239,8 @@ TALER_wallet_recoup_refresh_sign (
     .coin_blind = *coin_bks
   };
 
+  TALER_amount_hton (&pr.recoup_amount,
+                     requested_amount);
   GNUNET_CRYPTO_eddsa_sign (&coin_priv->eddsa_priv,
                             &pr,
                             &coin_sig->eddsa_signature);