-towards coin audits with purse deposits

src/auditor/auditor-basedb.age

@@ -1 +1 @@
-1655064974
+1655124520

src/auditor/auditor-basedb.conf

@@ -113,7 +113,7 @@ currency = TESTKUDOS
 [merchant-exchange-default]
 CURRENCY = TESTKUDOS
 EXCHANGE_BASE_URL = http://localhost:8081/
-MASTER_KEY = QRZFN2H2C1FANGHV76FBN11ESTK72VFCG3BVSRZA6PHJNT9WG3SG
+MASTER_KEY = GPB1CSPV6E49MET2PX6BFWVBGFF8BAE14M05RJB54C28EY1HX42G
 
 [merchant-account-merchant]
 ACTIVE_default = YES
@@ -157,7 +157,7 @@ CONFIG = postgres:///auditor-basedb
 [exchange]
 LOOKAHEAD_SIGN = 32 weeks 1 day
 SIGNKEY_DURATION = 4 weeks
-MASTER_PUBLIC_KEY = QRZFN2H2C1FANGHV76FBN11ESTK72VFCG3BVSRZA6PHJNT9WG3SG
+MASTER_PUBLIC_KEY = GPB1CSPV6E49MET2PX6BFWVBGFF8BAE14M05RJB54C28EY1HX42G
 SIGNKEY_LEGAL_DURATION = 4 weeks
 UNIXPATH = ${TALER_RUNTIME_DIR}/exchange.http
 
@@ -175,7 +175,7 @@ DATABASE = postgres:///auditor-basedb
 CONFIG = postgres:///auditor-basedb
 
 [auditor]
-PUBLIC_KEY = X25D3Y3K4SJZHP3KPP48R3PM9ZSYCEVEZK1SBXAMCRTTGN6CV32G
+PUBLIC_KEY = FBVV6V14GCCR95X2W2PMCBTFYZ4S3SX3JN504M8SJTMK1JBBV99G
 TINY_AMOUNT = TESTKUDOS:0.01
 BASE_URL = http://localhost:8083/
 

src/auditor/auditor-basedb.mpub

@@ -1 +1 @@
-QRZFN2H2C1FANGHV76FBN11ESTK72VFCG3BVSRZA6PHJNT9WG3SG
+GPB1CSPV6E49MET2PX6BFWVBGFF8BAE14M05RJB54C28EY1HX42G

src/auditor/report-lib.c

@@ -61,6 +61,11 @@ struct TALER_AuditorPublicKeyP TALER_ARL_auditor_pub;
  */
 char *TALER_ARL_auditor_url;
 
+/**
+ * REST API endpoint of the exchange.
+ */
+char *TALER_ARL_exchange_url;
+
 /**
  * At what time did the auditor process start?
  */
@@ -371,10 +376,13 @@ test_master_present (void *cls,
 {
   int *found = cls;
 
-  (void) exchange_url;
   if (0 == GNUNET_memcmp (mpub,
                           &TALER_ARL_master_pub))
+  {
     *found = GNUNET_YES;
+    GNUNET_free (TALER_ARL_exchange_url);
+    TALER_ARL_exchange_url = GNUNET_strdup (exchange_url);
+  }
 }
 
 
@@ -765,6 +773,7 @@ TALER_ARL_done (json_t *report)
                 JSON_INDENT (2));
     json_decref (report);
   }
+  GNUNET_free (TALER_ARL_exchange_url);
   GNUNET_free (TALER_ARL_auditor_url);
 }
 

src/auditor/report-lib.h

@@ -74,6 +74,11 @@ extern struct TALER_AuditorPublicKeyP TALER_ARL_auditor_pub;
  */
 extern char *TALER_ARL_auditor_url;
 
+/**
+ * REST API endpoint of the exchange.
+ */
+extern char *TALER_ARL_exchange_url;
+
 /**
  * At what time did the auditor process start?
  */

src/auditor/revoke-basedb.age

@@ -1 +1 @@
-1655066138
+1655124599

src/auditor/revoke-basedb.mpub

@@ -1 +1 @@
-RJD4G3ERAWDZRH8W4PMNKB9X75HB3N1A3MFKMHBH4FTAAD71GA90
+6CF031C2JWXQB98SNHARWSPJMYR8JM26BVDV08CPH63T2M9JXV30

src/auditor/taler-auditor-sync.c

@@ -115,6 +115,7 @@ static struct Table tables[] = {
   { .rt = TALER_EXCHANGEDB_RT_EXTENSIONS},
   { .rt = TALER_EXCHANGEDB_RT_EXTENSION_DETAILS },
   { .rt = TALER_EXCHANGEDB_RT_PURSE_REQUESTS},
+  { .rt = TALER_EXCHANGEDB_RT_PURSE_REFUNDS},
   { .rt = TALER_EXCHANGEDB_RT_PURSE_MERGES},
   { .rt = TALER_EXCHANGEDB_RT_PURSE_DEPOSITS},
   { .rt = TALER_EXCHANGEDB_RT_ACCOUNT_MERGES},

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

@@ -17,9 +17,6 @@
  * @file auditor/taler-helper-auditor-coins.c
  * @brief audits coins in an exchange database.
  * @author Christian Grothoff
- *
- * UNDECIDED:
- * - do we care about checking the 'done' flag in deposit_cb?
  */
 #include "platform.h"
 #include <gnunet/gnunet_util_lib.h>
@@ -248,7 +245,8 @@ get_cached_history (const struct TALER_CoinSpendPublicKeyP *coin_pub)
 {
   unsigned int i = coin_history_index (coin_pub);
 
-  if (0 == GNUNET_memcmp (coin_pub,
+  if (0 ==
+      GNUNET_memcmp (coin_pub,
                      &coin_histories[i].coin_pub))
   {
     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
@@ -479,7 +477,6 @@ check_coin_history (const struct TALER_CoinSpendPublicKeyP *coin_pub,
                                              &tl);
   if (0 >= qs)
     return qs;
-
   GNUNET_assert (GNUNET_OK ==
                  TALER_amount_set_zero (value->currency,
                                         &refunded));
@@ -538,6 +535,7 @@ check_coin_history (const struct TALER_CoinSpendPublicKeyP *coin_pub,
                             &pos->details.recoup_refresh->value);
       break;
     case TALER_EXCHANGEDB_TT_PURSE_DEPOSIT:
+      /* spent += pos->value */
       TALER_ARL_amount_add (&spent,
                             &spent,
                             &pos->details.purse_deposit->amount);
@@ -628,22 +626,22 @@ struct DenominationSummary
   const struct TALER_EXCHANGEDB_DenominationKeyInformation *issue;
 
   /**
-   * #GNUNET_YES if this record already existed in the DB.
+   * True if this record already existed in the DB.
    * Used to decide between insert/update in
    * #sync_denomination().
    */
-  int in_db;
+  bool in_db;
 
   /**
    * Should we report an emergency for this denomination, causing it to be
    * revoked (because more coins were deposited than issued)?
    */
-  int report_emergency;
+  bool report_emergency;
 
   /**
-   * #GNUNET_YES if this denomination was revoked.
+   * True if this denomination was revoked.
    */
-  int was_revoked;
+  bool was_revoked;
 };
 
 
@@ -695,7 +693,7 @@ init_denomination (const struct TALER_DenominationHashP *denom_hash,
   }
   if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT == qs)
   {
-    ds->in_db = GNUNET_YES;
+    ds->in_db = true;
   }
   else
   {
@@ -741,10 +739,10 @@ init_denomination (const struct TALER_DenominationHashP *denom_hash,
     }
     else
     {
-      ds->was_revoked = GNUNET_YES;
+      ds->was_revoked = true;
     }
   }
-  return (GNUNET_YES == ds->in_db)
+  return ds->in_db
          ? GNUNET_DB_STATUS_SUCCESS_ONE_RESULT
          : GNUNET_DB_STATUS_SUCCESS_NO_RESULTS;
 }
@@ -900,7 +898,7 @@ sync_denomination (void *cls,
                                    cnt,
                                    &ds->denom_risk);
       }
-      if (GNUNET_YES == ds->report_emergency)
+      if (ds->report_emergency)
       {
         /* Value of coins deposited exceed value of coins
            issued! Also very bad! */
@@ -1139,9 +1137,9 @@ reveal_data_cb (void *cls,
  *  #GNUNET_DB_STATUS_SUCCESS_ONE_RESULT
  */
 static enum GNUNET_DB_QueryStatus
-check_known_coin (const char *operation,
+check_known_coin (
-                  const struct
+  const char *operation,
-                  TALER_EXCHANGEDB_DenominationKeyInformation *issue,
+  const struct TALER_EXCHANGEDB_DenominationKeyInformation *issue,
   uint64_t rowid,
   const struct TALER_CoinSpendPublicKeyP *coin_pub,
   const struct TALER_DenominationPublicKey *denom_pub,
@@ -1463,6 +1461,7 @@ refresh_session_cb (void *cls,
   }
   else
   {
+    // FIXME: refactor: repeated logic!
     if (TALER_ARL_SR_INVALID_NEGATIVE ==
         TALER_ARL_amount_subtract_neg (&tmp,
                                        &dso->denom_balance,
@@ -1471,7 +1470,7 @@ refresh_session_cb (void *cls,
       TALER_ARL_amount_add (&dso->denom_loss,
                             &dso->denom_loss,
                             amount_with_fee);
-      dso->report_emergency = GNUNET_YES;
+      dso->report_emergency = true;
     }
     else
     {
@@ -1650,6 +1649,7 @@ deposit_cb (void *cls,
   {
     struct TALER_Amount tmp;
 
+    // FIXME: refactor: repeated logic!
     if (TALER_ARL_SR_INVALID_NEGATIVE ==
         TALER_ARL_amount_subtract_neg (&tmp,
                                        &ds->denom_balance,
@@ -1658,7 +1658,7 @@ deposit_cb (void *cls,
       TALER_ARL_amount_add (&ds->denom_loss,
                             &ds->denom_loss,
                             &deposit->amount_with_fee);
-      ds->report_emergency = GNUNET_YES;
+      ds->report_emergency = true;
     }
     else
     {
@@ -1718,6 +1718,7 @@ deposit_cb (void *cls,
  * @param merchant_sig signature of the merchant
  * @param h_contract_terms hash of the proposal data known to merchant and customer
  * @param rtransaction_id refund transaction ID chosen by the merchant
+ * @param full_refund true if the refunds total up to the entire deposited value
  * @param amount_with_fee amount that was deposited including fee
  * @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
  */
@@ -1730,6 +1731,7 @@ refund_cb (void *cls,
            const struct TALER_MerchantSignatureP *merchant_sig,
            const struct TALER_PrivateContractHashP *h_contract_terms,
            uint64_t rtransaction_id,
+           bool full_refund,
            const struct TALER_Amount *amount_with_fee)
 {
   struct CoinContext *cc = cls;
@@ -1840,6 +1842,153 @@ refund_cb (void *cls,
   TALER_ARL_amount_add (&total_refund_fee_income,
                         &total_refund_fee_income,
                         &issue->fees.refund);
+  if (full_refund)
+  {
+    TALER_ARL_amount_subtract (&total_deposit_fee_income,
+                               &total_deposit_fee_income,
+                               &issue->fees.deposit);
+  }
+  if (TALER_ARL_do_abort ())
+    return GNUNET_SYSERR;
+  return GNUNET_OK;
+}
+
+
+/**
+ * Function called with details about purse refunds that have been made, with
+ * the goal of auditing the purse refund's execution.
+ *
+ * @param cls closure
+ * @param amount_with_fee amount of the deposit into the purse
+ * @param coin_pub coin that is to be refunded the @a given amount_with_fee
+ * @param denom_pub denomination of @a coin_pub
+ * @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
+ */
+static enum GNUNET_GenericReturnValue
+purse_refund_coin_cb (
+  void *cls,
+  const struct TALER_Amount *amount_with_fee,
+  const struct TALER_CoinSpendPublicKeyP *coin_pub,
+  const struct TALER_DenominationPublicKey *denom_pub)
+{
+  struct CoinContext *cc = cls;
+
+#if FIXME
+  const struct TALER_EXCHANGEDB_DenominationKeyInformation *issue;
+  struct DenominationSummary *ds;
+  struct TALER_Amount amount_without_fee;
+  enum GNUNET_DB_QueryStatus qs;
+
+  qs = TALER_ARL_get_denomination_info (denom_pub,
+                                        &issue,
+                                        NULL);
+  if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
+  {
+    report_row_inconsistency ("purse-refunds",
+                              rowid,
+                              "denomination key not found");
+    if (TALER_ARL_do_abort ())
+      return GNUNET_SYSERR;
+    return GNUNET_OK;
+  }
+  if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT != qs)
+  {
+    GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);
+    return GNUNET_SYSERR;
+  }
+
+  if (TALER_ARL_SR_INVALID_NEGATIVE ==
+      TALER_ARL_amount_subtract_neg (&amount_without_fee,
+                                     amount_with_fee,
+                                     &issue->fees.refund))
+  {
+    report_amount_arithmetic_inconsistency ("refund (fee)",
+                                            rowid,
+                                            &amount_without_fee,
+                                            &issue->fees.refund,
+                                            -1);
+    if (TALER_ARL_do_abort ())
+      return GNUNET_SYSERR;
+    return GNUNET_OK;
+  }
+
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Refunding coin %s in denomination `%s' value %s\n",
+              TALER_B2S (coin_pub),
+              GNUNET_h2s (&issue->denom_hash.hash),
+              TALER_amount2s (amount_with_fee));
+
+  /* update coin's denomination balance */
+  ds = get_denomination_summary (cc,
+                                 issue,
+                                 &issue->denom_hash);
+  if (NULL == ds)
+  {
+    report_row_inconsistency ("refund",
+                              rowid,
+                              "denomination key for refunded coin unknown to auditor");
+  }
+  else
+  {
+    TALER_ARL_amount_add (&ds->denom_balance,
+                          &ds->denom_balance,
+                          &amount_without_fee);
+    TALER_ARL_amount_add (&ds->denom_risk,
+                          &ds->denom_risk,
+                          &amount_without_fee);
+    TALER_ARL_amount_add (&total_escrow_balance,
+                          &total_escrow_balance,
+                          &amount_without_fee);
+    TALER_ARL_amount_add (&total_risk,
+                          &total_risk,
+                          &amount_without_fee);
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "New balance of denomination `%s' after refund is %s\n",
+                GNUNET_h2s (&issue->denom_hash.hash),
+                TALER_amount2s (&ds->denom_balance));
+  }
+  /* update total refund fee balance */
+  TALER_ARL_amount_add (&total_refund_fee_income,
+                        &total_refund_fee_income,
+                        &issue->fees.refund);
+  TALER_ARL_amount_subtract (&total_deposit_fee_income,
+                             &total_deposit_fee_income,
+                             &issue->fees.deposit);
+
+#endif
+  return GNUNET_OK;
+}
+
+
+/**
+ * Function called with details about a purse that was refunded.  Adds the
+ * refunded amounts back to the outstanding balance of the respective
+ * denominations.
+ *
+ * @param cls closure
+ * @param rowid unique serial ID for the refund in our DB
+ * @param purse_pub public key of the purse
+ * @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
+ */
+static enum GNUNET_GenericReturnValue
+purse_refund_cb (void *cls,
+                 uint64_t rowid,
+                 const struct TALER_PurseContractPublicKeyP *purse_pub)
+{
+  struct CoinContext *cc = cls;
+  enum GNUNET_DB_QueryStatus qs;
+
+  GNUNET_assert (rowid >= ppc.last_purse_refunds_serial_id); /* should be monotonically increasing */
+  ppc.last_purse_refunds_serial_id = rowid + 1;
+  qs = TALER_ARL_edb->select_purse_deposits_by_purse (TALER_ARL_edb->cls,
+                                                      purse_pub,
+                                                      &purse_refund_coin_cb,
+                                                      cc);
+  if (qs < 0)
+  {
+    GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);
+    return GNUNET_SYSERR;
+  }
   if (TALER_ARL_do_abort ())
     return GNUNET_SYSERR;
   return GNUNET_OK;
@@ -1934,7 +2083,7 @@ check_recoup (struct CoinContext *cc,
   }
   else
   {
-    if (GNUNET_NO == ds->was_revoked)
+    if (! ds->was_revoked)
     {
       /* Woopsie, we allowed recoup on non-revoked denomination!? */
       TALER_ARL_report (report_bad_sig_losses,
@@ -2233,9 +2382,131 @@ purse_deposit_cb (
   const struct TALER_DenominationPublicKey *denom_pub)
 {
   struct CoinContext *cc = cls;
+  enum GNUNET_DB_QueryStatus qs;
+  struct TALER_DenominationHashP dh;
+  const struct TALER_EXCHANGEDB_DenominationKeyInformation *issue;
+  struct DenominationSummary *ds;
 
-  GNUNET_break (0); // FIXME: not implemented!
+  GNUNET_assert (rowid >= ppc.last_purse_deposits_serial_id);
+  ppc.last_purse_deposits_serial_id = rowid + 1;
+  qs = TALER_ARL_get_denomination_info (denom_pub,
+                                        &issue,
+                                        &dh);
+  if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
+  {
+    report_row_inconsistency ("purse-deposits",
+                              rowid,
+                              "denomination key not found");
+    if (TALER_ARL_do_abort ())
       return GNUNET_SYSERR;
+    return GNUNET_OK;
+  }
+  qs = check_known_coin ("purse-deposit",
+                         issue,
+                         rowid,
+                         &deposit->coin_pub,
+                         denom_pub,
+                         &deposit->amount);
+  if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT != qs)
+  {
+    GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);
+    cc->qs = qs;
+    return GNUNET_SYSERR;
+  }
+
+  if (GNUNET_OK !=
+      TALER_wallet_purse_deposit_verify (
+        NULL != deposit->exchange_base_url
+        ? deposit->exchange_base_url
+        : TALER_ARL_exchange_url,
+        &deposit->purse_pub,
+        &deposit->amount,
+        &deposit->coin_pub,
+        &deposit->coin_sig))
+  {
+    TALER_ARL_report (report_bad_sig_losses,
+                      GNUNET_JSON_PACK (
+                        GNUNET_JSON_pack_string ("operation",
+                                                 "purse-deposit"),
+                        GNUNET_JSON_pack_uint64 ("row",
+                                                 rowid),
+                        TALER_JSON_pack_amount ("loss",
+                                                &deposit->amount),
+                        GNUNET_JSON_pack_data_auto ("coin_pub",
+                                                    &deposit->coin_pub)));
+    TALER_ARL_amount_add (&total_bad_sig_loss,
+                          &total_bad_sig_loss,
+                          &deposit->amount);
+    if (TALER_ARL_do_abort ())
+      return GNUNET_SYSERR;
+    return GNUNET_OK;
+  }
+
+  /* update coin's denomination balance */
+  ds = get_denomination_summary (cc,
+                                 issue,
+                                 &issue->denom_hash);
+  if (NULL == ds)
+  {
+    report_row_inconsistency ("purse-deposit",
+                              rowid,
+                              "denomination key for purse-deposited coin unknown to auditor");
+  }
+  else
+  {
+    struct TALER_Amount tmp;
+
+    // FIXME: refactor: repeated logic!
+    if (TALER_ARL_SR_INVALID_NEGATIVE ==
+        TALER_ARL_amount_subtract_neg (&tmp,
+                                       &ds->denom_balance,
+                                       &deposit->amount))
+    {
+      TALER_ARL_amount_add (&ds->denom_loss,
+                            &ds->denom_loss,
+                            &deposit->amount);
+      ds->report_emergency = true;
+    }
+    else
+    {
+      ds->denom_balance = tmp;
+    }
+    if (-1 == TALER_amount_cmp (&total_escrow_balance,
+                                &deposit->amount))
+    {
+      /* This can theoretically happen if for example the exchange
+         never issued any coins (i.e. escrow balance is zero), but
+         accepted a forged coin (i.e. emergency situation after
+         private key compromise). In that case, we cannot even
+         subtract the profit we make from the fee from the escrow
+         balance. Tested as part of test-auditor.sh, case #18 */
+      report_amount_arithmetic_inconsistency (
+        "subtracting purse deposit fee from escrow balance",
+        rowid,
+        &total_escrow_balance,
+        &deposit->amount,
+        0);
+    }
+    else
+    {
+      TALER_ARL_amount_subtract (&total_escrow_balance,
+                                 &total_escrow_balance,
+                                 &deposit->amount);
+    }
+
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "New balance of denomination `%s' after purse deposit is %s\n",
+                GNUNET_h2s (&issue->denom_hash.hash),
+                TALER_amount2s (&ds->denom_balance));
+  }
+
+  /* update global deposit fees */
+  TALER_ARL_amount_add (&total_deposit_fee_income,
+                        &total_deposit_fee_income,
+                        &issue->fees.deposit);
+  if (TALER_ARL_do_abort ())
+    return GNUNET_SYSERR;
+  return GNUNET_OK;
 }
 
 
@@ -2339,6 +2610,20 @@ analyze_coins (void *cls)
   if (0 > cc.qs)
     return cc.qs;
 
+  /* process purse_refunds */
+  if (0 >
+      (qs = TALER_ARL_edb->select_purse_refunds_above_serial_id (
+         TALER_ARL_edb->cls,
+         ppc.last_purse_refunds_serial_id,
+         &purse_refund_cb,
+         &cc)))
+  {
+    GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR == qs);
+    return qs;
+  }
+  if (0 > cc.qs)
+    return cc.qs;
+
   /* process recoups */
   if (0 >
       (qs = TALER_ARL_edb->select_recoup_refresh_above_serial_id (
@@ -2631,8 +2916,11 @@ run (void *cls,
       GNUNET_JSON_pack_uint64 ("start_ppc_recoup_serial_id",
                                ppc_start.last_recoup_serial_id),
       GNUNET_JSON_pack_uint64 ("start_ppc_recoup_refresh_serial_id",
-                               ppc_start.
+                               ppc_start.last_recoup_refresh_serial_id),
-                               last_recoup_refresh_serial_id),
+      GNUNET_JSON_pack_uint64 ("start_ppc_purse_deposits_serial_id",
+                               ppc_start.last_purse_deposits_serial_id),
+      GNUNET_JSON_pack_uint64 ("start_ppc_purse_refunds_serial_id",
+                               ppc_start.last_purse_refunds_serial_id),
       GNUNET_JSON_pack_uint64 ("end_ppc_withdraw_serial_id",
                                ppc.last_withdraw_serial_id),
       GNUNET_JSON_pack_uint64 ("end_ppc_deposit_serial_id",
@@ -2645,6 +2933,10 @@ run (void *cls,
                                ppc.last_recoup_serial_id),
       GNUNET_JSON_pack_uint64 ("end_ppc_recoup_refresh_serial_id",
                                ppc.last_recoup_refresh_serial_id),
+      GNUNET_JSON_pack_uint64 ("end_ppc_purse_deposits_serial_id",
+                               ppc.last_purse_deposits_serial_id),
+      GNUNET_JSON_pack_uint64 ("end_ppc_purse_refunds_serial_id",
+                               ppc.last_purse_refunds_serial_id),
       TALER_JSON_pack_time_abs_human ("auditor_start_time",
                                       start_time),
       TALER_JSON_pack_time_abs_human ("auditor_end_time",

src/auditordb/auditor-0001.sql

@@ -87,6 +87,7 @@ CREATE TABLE IF NOT EXISTS auditor_progress_coin
   ,last_recoup_serial_id INT8 NOT NULL DEFAULT 0
   ,last_recoup_refresh_serial_id INT8 NOT NULL DEFAULT 0
   ,last_purse_deposits_serial_id INT8 NOT NULL DEFAULT 0
+  ,last_purse_refunds_serial_id INT8 NOT NULL DEFAULT 0
   ,PRIMARY KEY (master_pub)
   );
 COMMENT ON TABLE auditor_progress_coin

src/auditordb/plugin_auditordb_postgres.c

@@ -314,8 +314,9 @@ setup_connection (struct PostgresClosure *pg)
                             ",last_recoup_serial_id=$5"
                             ",last_recoup_refresh_serial_id=$6"
                             ",last_purse_deposits_serial_id=$7"
-                            " WHERE master_pub=$8",
+                            ",last_purse_refunds_serial_id=$8"
-                            8),
+                            " WHERE master_pub=$9",
+                            9),
     /* Used in #postgres_get_auditor_progress_coin() */
     GNUNET_PQ_make_prepare ("auditor_progress_select_coin",
                             "SELECT"
@@ -326,6 +327,7 @@ setup_connection (struct PostgresClosure *pg)
                             ",last_recoup_serial_id"
                             ",last_recoup_refresh_serial_id"
                             ",last_purse_deposits_serial_id"
+                            ",last_purse_refunds_serial_id"
                             " FROM auditor_progress_coin"
                             " WHERE master_pub=$1;",
                             1),
@@ -340,8 +342,9 @@ setup_connection (struct PostgresClosure *pg)
                             ",last_recoup_serial_id"
                             ",last_recoup_refresh_serial_id"
                             ",last_purse_deposits_serial_id"
-                            ") VALUES ($1,$2,$3,$4,$5,$6,$7,$8);",
+                            ",last_purse_refunds_serial_id"
-                            8),
+                            ") VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9);",
+                            9),
     /* Used in #postgres_insert_wire_auditor_account_progress() */
     GNUNET_PQ_make_prepare ("wire_auditor_account_progress_insert",
                             "INSERT INTO wire_auditor_account_progress "
@@ -1535,6 +1538,7 @@ postgres_insert_auditor_progress_coin (
     GNUNET_PQ_query_param_uint64 (&ppc->last_recoup_serial_id),
     GNUNET_PQ_query_param_uint64 (&ppc->last_recoup_refresh_serial_id),
     GNUNET_PQ_query_param_uint64 (&ppc->last_purse_deposits_serial_id),
+    GNUNET_PQ_query_param_uint64 (&ppc->last_purse_refunds_serial_id),
     GNUNET_PQ_query_param_end
   };
 
@@ -1568,6 +1572,7 @@ postgres_update_auditor_progress_coin (
     GNUNET_PQ_query_param_uint64 (&ppc->last_recoup_serial_id),
     GNUNET_PQ_query_param_uint64 (&ppc->last_recoup_refresh_serial_id),
     GNUNET_PQ_query_param_uint64 (&ppc->last_purse_deposits_serial_id),
+    GNUNET_PQ_query_param_uint64 (&ppc->last_purse_refunds_serial_id),
     GNUNET_PQ_query_param_auto_from_type (master_pub),
     GNUNET_PQ_query_param_end
   };
@@ -1612,6 +1617,8 @@ postgres_get_auditor_progress_coin (
                                   &ppc->last_recoup_refresh_serial_id),
     GNUNET_PQ_result_spec_uint64 ("last_purse_deposits_serial_id",
                                   &ppc->last_purse_deposits_serial_id),
+    GNUNET_PQ_result_spec_uint64 ("last_purse_refunds_serial_id",
+                                  &ppc->last_purse_refunds_serial_id),
     GNUNET_PQ_result_spec_end
   };
 

src/exchangedb/Makefile.am

@@ -14,16 +14,24 @@ pkgcfg_DATA = \
 
 sqldir = $(prefix)/share/taler/sql/exchange/
 
+sqlinputs = \
+  common-0001.sql \
+  drop-common.sql \
+  exchange-0001-part.sql \
+  drop0001-exchange-part.sql \
+  shard-0001-part.sql \
+  drop0001-shard-part.sql
+
 sql_DATA = \
   benchmark-0000.sql \
   benchmark-0001.sql \
   exchange-0000.sql \
-  exchange-0001-part.sql \
+  exchange-0001.sql \
-  shard-0001-part.sql \
+  drop0001.sql \
-  common-0001.sql \
+  shard-0000.sql \
-  drop-common.sql \
+  shard-0001.sql \
-  drop0001-exchange-part.sql \
+  shard-drop0001.sql
-  drop0001-shard-part.sql
+
 
 BUILT_SOURCES = \
   shard-0000.sql \
@@ -40,22 +48,27 @@ CLEANFILES = \
   shard-drop0001.sql
 
 exchange-0001.sql: common-0001.sql exchange-0001-part.sql
+	chmod +w $@ || true
 	cat common-0001.sql exchange-0001-part.sql >$@
 	chmod -w $@
 
 shard-0001.sql: common-0001.sql shard-0001-part.sql
+	chmod +w $@ || true
 	cat common-0001.sql shard-0001-part.sql >$@
 	chmod -w $@
 
 shard-0000.sql: exchange-0000.sql
+	chmod +w $@ || true
 	cp exchange-0000.sql $@
 	chmod -w $@
 
 drop0001.sql: drop-common.sql drop0001-exchange-part.sql
+	chmod +w $@ || true
 	cat drop-common.sql drop0001-exchange-part.sql >$@
 	chmod -w $@
 
 shard-drop0001.sql: drop-common.sql drop0001-shard-part.sql
+	chmod +w $@ || true
 	cat drop-common.sql drop0001-shard-part.sql >$@
 	chmod -w $@
 
@@ -67,6 +80,7 @@ EXTRA_DIST = \
   lrbt_callbacks.c \
   bench-db-postgres.conf \
   test-exchange-db-postgres.conf \
+  $(sqlinputs) \
   $(sql_DATA)
 
 plugindir = $(libdir)/taler

src/exchangedb/common-0001.sql

@@ -1219,6 +1219,54 @@ BEGIN
 END
 $$;
 
+
+------------------------------- purse_refunds ----------------------------------------
+
+CREATE OR REPLACE FUNCTION create_table_purse_refunds(
+  IN shard_suffix VARCHAR DEFAULT NULL
+)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+DECLARE
+  table_name VARCHAR DEFAULT 'purse_refunds';
+BEGIN
+
+  PERFORM create_partitioned_table(
+    'CREATE TABLE IF NOT EXISTS %I '
+      '(purse_refunds_serial_id BIGINT GENERATED BY DEFAULT AS IDENTITY' --UNIQUE
+      ',purse_pub BYTEA NOT NULL CHECK (LENGTH(purse_pub)=32)'
+      ',PRIMARY KEY (purse_pub)'
+    ') %s ;'
+    ,table_name
+    ,'PARTITION BY HASH (purse_pub)'
+    ,shard_suffix
+  );
+
+  table_name = concat_ws('_', table_name, shard_suffix);
+
+END
+$$;
+
+CREATE OR REPLACE FUNCTION add_constraints_to_purse_refunds_partition(
+  IN partition_suffix VARCHAR
+)
+RETURNS VOID
+LANGUAGE plpgsql
+AS $$
+BEGIN
+  EXECUTE FORMAT (
+    'ALTER TABLE purse_refunds_' || partition_suffix || ' '
+      'ADD CONSTRAINT purse_refunds_' || partition_suffix || '_purse_refunds_serial_id_key '
+        'UNIQUE (purse_refunds_serial_id) '
+  );
+END
+$$;
+
+
+
+
+
 ---------------------------- purse_merges -----------------------------
 
 CREATE OR REPLACE FUNCTION create_table_purse_merges(
@@ -1828,6 +1876,9 @@ BEGIN
   ALTER TABLE IF EXISTS purse_requests
     DETACH partition purse_requests_default;
 
+  ALTER TABLE IF EXISTS purse_refunds
+    DETACH partition purse_refunds_default;
+
   ALTER TABLE IF EXISTS purse_merges
     DETACH partition purse_merges_default;
 
@@ -1894,6 +1945,7 @@ BEGIN
   DROP TABLE IF EXISTS cs_nonce_locks_default;
 
   DROP TABLE IF EXISTS purse_requests_default;
+  DROP TABLE IF EXISTS purse_refunds_default;
   DROP TABLE IF EXISTS purse_merges_default;
   DROP TABLE IF EXISTS account_merges_default;
   DROP TABLE IF EXISTS contracts_default;
@@ -2105,6 +2157,13 @@ BEGIN
     );
     PERFORM add_constraints_to_purse_requests_partition(num_partitions::varchar);
 
+    PERFORM create_hash_partition(
+      'purse_refunds'
+      ,modulus
+      ,num_partitions
+    );
+    PERFORM add_constraints_to_purse_refunds_partition(num_partitions::varchar);
+
     PERFORM create_hash_partition(
       'purse_merges'
       ,modulus
@@ -2316,6 +2375,10 @@ BEGIN
     DROP CONSTRAINT IF EXISTS purse_requests_pkey CASCADE
   ;
 
+  ALTER TABLE IF EXISTS purse_refunds
+    DROP CONSTRAINT IF EXISTS purse_refunds_pkey CASCADE
+  ;
+
   ALTER TABLE IF EXISTS purse_merges
     DROP CONSTRAINT IF EXISTS purse_merges_pkey CASCADE
   ;
@@ -2571,6 +2634,13 @@ BEGIN
     ,current_shard_num
     ,local_user
   );
+  PERFORM create_foreign_hash_partition(
+    'purse_refunds'
+    ,total_num_shards
+    ,shard_suffix
+    ,current_shard_num
+    ,local_user
+  );
   PERFORM create_foreign_hash_partition(
     'purse_merges'
     ,total_num_shards

src/exchangedb/drop-common.sql

@@ -63,6 +63,8 @@ DROP FUNCTION IF EXISTS add_constraints_to_cs_nonce_locks_partition;
 
 DROP FUNCTION IF EXISTS create_table_purse_requests;
 DROP FUNCTION IF EXISTS add_constraints_to_purse_requests_partition;
+DROP FUNCTION IF EXISTS create_table_purse_refunds;
+DROP FUNCTION IF EXISTS add_constraints_to_purse_refunds_partition;
 DROP FUNCTION IF EXISTS create_table_purse_merges;
 DROP FUNCTION IF EXISTS add_constraints_to_purse_merges_partition;
 DROP FUNCTION IF EXISTS create_table_account_merges;

src/exchangedb/drop0001-exchange-part.sql

@@ -73,6 +73,7 @@ DROP TABLE IF EXISTS contracts CASCADE;
 DROP TABLE IF EXISTS history_requests CASCADE;
 DROP TABLE IF EXISTS close_requests CASCADE;
 DROP TABLE IF EXISTS purse_requests CASCADE;
+DROP TABLE IF EXISTS purse_refunds CASCADE;
 DROP TABLE IF EXISTS wads_out CASCADE;
 DROP TABLE IF EXISTS wad_out_entries CASCADE;
 DROP TABLE IF EXISTS wads_in CASCADE;

src/exchangedb/exchange-0001-part.sql

@@ -1040,6 +1040,21 @@ CREATE TABLE IF NOT EXISTS purse_requests_default
 SELECT add_constraints_to_purse_requests_partition('default');
 
 
+-- ------------------------------ purse_refunds ----------------------------------------
+
+SELECT create_table_purse_refunds();
+
+COMMENT ON TABLE purse_refunds
+  IS 'Purses that were refunded due to expiration';
+COMMENT ON COLUMN purse_refunds.purse_pub
+  IS 'Public key of the purse';
+
+CREATE TABLE IF NOT EXISTS purse_refunds_default
+  PARTITION OF purse_refunds
+  FOR VALUES WITH (MODULUS 1, REMAINDER 0);
+
+SELECT add_constraints_to_purse_refunds_partition('default');
+
 
 -- ------------------------------ purse_merges ----------------------------------------
 
@@ -3485,6 +3500,11 @@ UPDATE purse_requests
      finished=TRUE
  WHERE purse_pub=my_purse_pub;
 
+INSERT INTO purse_refunds
+ (purse_pub)
+ VALUES
+ (my_purse_pub);
+
 -- restore balance to each coin deposited into the purse
 FOR my_deposit IN
   SELECT coin_pub

src/exchangedb/irbt_callbacks.c

@@ -809,6 +809,8 @@ irbt_cb_table_purse_requests (struct PostgresClosure *pg,
 {
   struct GNUNET_PQ_QueryParam params[] = {
     GNUNET_PQ_query_param_uint64 (&td->serial),
+    GNUNET_PQ_query_param_auto_from_type (
+      &td->details.purse_requests.purse_pub),
     GNUNET_PQ_query_param_auto_from_type (
       &td->details.purse_requests.merge_pub),
     GNUNET_PQ_query_param_timestamp (
@@ -832,6 +834,29 @@ irbt_cb_table_purse_requests (struct PostgresClosure *pg,
 }
 
 
+/**
+ * Function called with purse_refunds records to insert into table.
+ *
+ * @param pg plugin context
+ * @param td record to insert
+ */
+static enum GNUNET_DB_QueryStatus
+irbt_cb_table_purse_refunds (struct PostgresClosure *pg,
+                             const struct TALER_EXCHANGEDB_TableData *td)
+{
+  struct GNUNET_PQ_QueryParam params[] = {
+    GNUNET_PQ_query_param_uint64 (&td->serial),
+    GNUNET_PQ_query_param_auto_from_type (
+      &td->details.purse_refunds.purse_pub),
+    GNUNET_PQ_query_param_end
+  };
+
+  return GNUNET_PQ_eval_prepared_non_select (pg->conn,
+                                             "insert_into_table_purse_refunds",
+                                             params);
+}
+
+
 /**
  * Function called with purse_merges records to insert into table.
  *

src/exchangedb/lrbt_callbacks.c

@@ -1549,6 +1549,51 @@ lrbt_cb_table_purse_requests (void *cls,
 }
 
 
+/**
+ * Function called with purse_refunds table entries.
+ *
+ * @param cls closure
+ * @param result the postgres result
+ * @param num_results the number of results in @a result
+ */
+static void
+lrbt_cb_table_purse_refunds (void *cls,
+                             PGresult *result,
+                             unsigned int num_results)
+{
+  struct LookupRecordsByTableContext *ctx = cls;
+  struct TALER_EXCHANGEDB_TableData td = {
+    .table = TALER_EXCHANGEDB_RT_PURSE_REFUNDS
+  };
+
+  for (unsigned int i = 0; i<num_results; i++)
+  {
+    struct GNUNET_PQ_ResultSpec rs[] = {
+      GNUNET_PQ_result_spec_uint64 (
+        "purse_refunds_serial_id",
+        &td.serial),
+      GNUNET_PQ_result_spec_auto_from_type (
+        "purse_pub",
+        &td.details.purse_refunds.purse_pub),
+      GNUNET_PQ_result_spec_end
+    };
+
+    if (GNUNET_OK !=
+        GNUNET_PQ_extract_result (result,
+                                  rs,
+                                  i))
+    {
+      GNUNET_break (0);
+      ctx->error = true;
+      return;
+    }
+    ctx->cb (ctx->cb_cls,
+             &td);
+    GNUNET_PQ_cleanup_result (rs);
+  }
+}
+
+
 /**
  * Function called with purse_merges table entries.
  *

src/exchangedb/plugin_exchangedb_postgres.c

@@ -1407,6 +1407,19 @@ prepare_statements (struct PostgresClosure *pg)
       " WHERE ref.refund_serial_id>=$1"
       " ORDER BY ref.refund_serial_id ASC;",
       1),
+    GNUNET_PQ_make_prepare (
+      "test_refund_full",
+      "SELECT"
+      " CAST(SUM(CAST(ref.amount_with_fee_frac AS INT8)) AS INT8) AS s_f"
+      ",CAST(SUM(ref.amount_with_fee_val) AS INT8) AS s_v"
+      ",dep.amount_with_fee_val"
+      ",dep.amount_with_fee_frac"
+      " FROM refunds ref"
+      "   JOIN deposits dep"
+      "     ON (ref.coin_pub=dep.coin_pub AND ref.deposit_serial_id=dep.deposit_serial_id)"
+      " WHERE ref.refund_serial_id=$1"
+      " GROUP BY (dep.amount_with_fee_val, dep.amount_with_fee_frac);",
+      1),
 
     /* Store information about a /deposit the exchange is to execute.
        Used in #postgres_insert_deposit().  Only used in test cases. */
@@ -1508,6 +1521,29 @@ prepare_statements (struct PostgresClosure *pg)
       " )"
       " ORDER BY purse_deposit_serial_id ASC;",
       1),
+    GNUNET_PQ_make_prepare (
+      "audit_get_purse_deposits_by_purse",
+      "SELECT"
+      " pd.amount_with_fee_val"
+      ",pd.amount_with_fee_frac"
+      ",pd.coin_pub"
+      ",denom.denom_pub"
+      " FROM purse_deposits pd"
+      " JOIN known_coins kc USING (coin_pub)"
+      " JOIN denominations denom USING (denominations_serial)"
+      " WHERE purse_pub=$1;",
+      1),
+    GNUNET_PQ_make_prepare (
+      "audit_get_purse_refunds_incr",
+      "SELECT"
+      " purse_pub"
+      ",purse_refunds_serial_id"
+      " FROM purse_refunds"
+      " WHERE ("
+      "  (purse_refunds_serial_id>=$1)"
+      " )"
+      " ORDER BY purse_refunds_serial_id ASC;",
+      1),
     /* Fetch an existing deposit request.
        Used in #postgres_lookup_transfer_by_deposit(). */
     GNUNET_PQ_make_prepare (
@@ -2778,6 +2814,14 @@ prepare_statements (struct PostgresClosure *pg)
       " ORDER BY purse_requests_serial_id DESC"
       " LIMIT 1;",
       0),
+    GNUNET_PQ_make_prepare (
+      "select_serial_by_table_purse_refunds",
+      "SELECT"
+      " purse_refunds_serial_id AS serial"
+      " FROM purse_refunds"
+      " ORDER BY purse_refunds_serial_id DESC"
+      " LIMIT 1;",
+      0),
     GNUNET_PQ_make_prepare (
       "select_serial_by_table_purse_merges",
       "SELECT"
@@ -3212,6 +3256,15 @@ prepare_statements (struct PostgresClosure *pg)
       " WHERE purse_requests_serial_id > $1"
       " ORDER BY purse_requests_serial_id ASC;",
       1),
+    GNUNET_PQ_make_prepare (
+      "select_above_serial_by_table_purse_refunds",
+      "SELECT"
+      " purse_refunds_serial_id"
+      ",purse_pub"
+      " FROM purse_refunds"
+      " WHERE purse_refunds_serial_id > $1"
+      " ORDER BY purse_refunds_serial_id ASC;",
+      1),
     GNUNET_PQ_make_prepare (
       "select_above_serial_by_table_purse_merges",
       "SELECT"
@@ -3688,6 +3741,14 @@ prepare_statements (struct PostgresClosure *pg)
       ") VALUES "
       "($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13);",
       13),
+    GNUNET_PQ_make_prepare (
+      "insert_into_table_purse_refunds",
+      "INSERT INTO purse_refunds"
+      "(purse_refunds_serial_id"
+      ",purse_pub"
+      ") VALUES "
+      "($1, $2);",
+      2),
     GNUNET_PQ_make_prepare (
       "insert_into_table_purse_merges",
       "INSERT INTO purse_merges"
@@ -10496,6 +10557,242 @@ postgres_select_purse_deposits_above_serial_id (
 }
 
 
+/**
+ * Closure for #purse_refund_serial_helper_cb().
+ */
+struct PurseRefundSerialContext
+{
+
+  /**
+   * Callback to call.
+   */
+  TALER_EXCHANGEDB_PurseRefundCallback cb;
+
+  /**
+   * Closure for @e cb.
+   */
+  void *cb_cls;
+
+  /**
+   * Plugin context.
+   */
+  struct PostgresClosure *pg;
+
+  /**
+   * Status code, set to #GNUNET_SYSERR on hard errors.
+   */
+  enum GNUNET_GenericReturnValue status;
+};
+
+
+/**
+ * Helper function to be called with the results of a SELECT statement
+ * that has returned @a num_results results.
+ *
+ * @param cls closure of type `struct PurseRefundSerialContext`
+ * @param result the postgres result
+ * @param num_results the number of results in @a result
+ */
+static void
+purse_refund_serial_helper_cb (void *cls,
+                               PGresult *result,
+                               unsigned int num_results)
+{
+  struct PurseRefundSerialContext *dsc = cls;
+
+  for (unsigned int i = 0; i<num_results; i++)
+  {
+    struct TALER_PurseContractPublicKeyP purse_pub;
+    uint64_t rowid;
+    struct GNUNET_PQ_ResultSpec rs[] = {
+      GNUNET_PQ_result_spec_auto_from_type ("purse_pub",
+                                            &purse_pub),
+      GNUNET_PQ_result_spec_uint64 ("purse_deposit_serial_id",
+                                    &rowid),
+      GNUNET_PQ_result_spec_end
+    };
+    enum GNUNET_GenericReturnValue ret;
+
+    if (GNUNET_OK !=
+        GNUNET_PQ_extract_result (result,
+                                  rs,
+                                  i))
+    {
+      GNUNET_break (0);
+      dsc->status = GNUNET_SYSERR;
+      return;
+    }
+    ret = dsc->cb (dsc->cb_cls,
+                   rowid,
+                   &purse_pub);
+    GNUNET_PQ_cleanup_result (rs);
+    if (GNUNET_OK != ret)
+      break;
+  }
+}
+
+
+/**
+ * Select purse refunds above @a serial_id in monotonically increasing
+ * order.
+ *
+ * @param cls closure
+ * @param serial_id highest serial ID to exclude (select strictly larger)
+ * @param cb function to call on each result
+ * @param cb_cls closure for @a cb
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_select_purse_refunds_above_serial_id (
+  void *cls,
+  uint64_t serial_id,
+  TALER_EXCHANGEDB_PurseRefundCallback cb,
+  void *cb_cls)
+{
+  struct PostgresClosure *pg = cls;
+  struct GNUNET_PQ_QueryParam params[] = {
+    GNUNET_PQ_query_param_uint64 (&serial_id),
+    GNUNET_PQ_query_param_end
+  };
+  struct PurseRefundSerialContext dsc = {
+    .cb = cb,
+    .cb_cls = cb_cls,
+    .pg = pg,
+    .status = GNUNET_OK
+  };
+  enum GNUNET_DB_QueryStatus qs;
+
+  qs = GNUNET_PQ_eval_prepared_multi_select (pg->conn,
+                                             "audit_get_purse_refunds_incr",
+                                             params,
+                                             &purse_refund_serial_helper_cb,
+                                             &dsc);
+  if (GNUNET_OK != dsc.status)
+    return GNUNET_DB_STATUS_HARD_ERROR;
+  return qs;
+}
+
+
+/**
+ * Closure for #purse_refund_coin_helper_cb().
+ */
+struct PurseRefundCoinContext
+{
+
+  /**
+   * Callback to call.
+   */
+  TALER_EXCHANGEDB_PurseRefundCoinCallback cb;
+
+  /**
+   * Closure for @e cb.
+   */
+  void *cb_cls;
+
+  /**
+   * Plugin context.
+   */
+  struct PostgresClosure *pg;
+
+  /**
+   * Status code, set to #GNUNET_SYSERR on hard errors.
+   */
+  enum GNUNET_GenericReturnValue status;
+};
+
+
+/**
+ * Helper function to be called with the results of a SELECT statement
+ * that has returned @a num_results results.
+ *
+ * @param cls closure of type `struct PurseRefundCoinContext`
+ * @param result the postgres result
+ * @param num_results the number of results in @a result
+ */
+static void
+purse_refund_coin_helper_cb (void *cls,
+                             PGresult *result,
+                             unsigned int num_results)
+{
+  struct PurseRefundCoinContext *dsc = cls;
+  struct PostgresClosure *pg = dsc->pg;
+
+  for (unsigned int i = 0; i<num_results; i++)
+  {
+    struct TALER_Amount amount_with_fee;
+    struct TALER_CoinSpendPublicKeyP coin_pub;
+    struct TALER_DenominationPublicKey denom_pub;
+    struct GNUNET_PQ_ResultSpec rs[] = {
+      TALER_PQ_result_spec_denom_pub ("denom_pub",
+                                      &denom_pub),
+      TALER_PQ_RESULT_SPEC_AMOUNT ("amount_with_fee",
+                                   &amount_with_fee),
+      GNUNET_PQ_result_spec_auto_from_type ("coin_pub",
+                                            &coin_pub),
+      GNUNET_PQ_result_spec_end
+    };
+    enum GNUNET_GenericReturnValue ret;
+
+    if (GNUNET_OK !=
+        GNUNET_PQ_extract_result (result,
+                                  rs,
+                                  i))
+    {
+      GNUNET_break (0);
+      dsc->status = GNUNET_SYSERR;
+      return;
+    }
+    ret = dsc->cb (dsc->cb_cls,
+                   &amount_with_fee,
+                   &coin_pub,
+                   &denom_pub);
+    GNUNET_PQ_cleanup_result (rs);
+    if (GNUNET_OK != ret)
+      break;
+  }
+}
+
+
+/**
+ * Select coin affected by purse refund.
+ *
+ * @param cls closure
+ * @param purse_pub purse that was refunded
+ * @param cb function to call on each result
+ * @param cb_cls closure for @a cb
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_select_purse_deposits_by_purse (
+  void *cls,
+  const struct TALER_PurseContractPublicKeyP *purse_pub,
+  TALER_EXCHANGEDB_PurseRefundCoinCallback cb,
+  void *cb_cls)
+{
+  struct PostgresClosure *pg = cls;
+  struct GNUNET_PQ_QueryParam params[] = {
+    GNUNET_PQ_query_param_auto_from_type (purse_pub),
+    GNUNET_PQ_query_param_end
+  };
+  struct PurseRefundCoinContext dsc = {
+    .cb = cb,
+    .cb_cls = cb_cls,
+    .pg = pg,
+    .status = GNUNET_OK
+  };
+  enum GNUNET_DB_QueryStatus qs;
+
+  qs = GNUNET_PQ_eval_prepared_multi_select (pg->conn,
+                                             "audit_get_purse_deposits_by_purse",
+                                             params,
+                                             &purse_refund_coin_helper_cb,
+                                             &dsc);
+  if (GNUNET_OK != dsc.status)
+    return GNUNET_DB_STATUS_HARD_ERROR;
+  return qs;
+}
+
+
 /**
  * Closure for #refreshs_serial_helper_cb().
  */
@@ -10690,6 +10987,7 @@ refunds_serial_helper_cb (void *cls,
     struct TALER_EXCHANGEDB_Refund refund;
     struct TALER_DenominationPublicKey denom_pub;
     uint64_t rowid;
+    bool full_refund;
     struct GNUNET_PQ_ResultSpec rs[] = {
       GNUNET_PQ_result_spec_auto_from_type ("merchant_pub",
                                             &refund.details.merchant_pub),
@@ -10720,6 +11018,42 @@ refunds_serial_helper_cb (void *cls,
       rsc->status = GNUNET_SYSERR;
       return;
     }
+    {
+      struct GNUNET_PQ_QueryParam params[] = {
+        GNUNET_PQ_query_param_uint64 (&rowid),
+        GNUNET_PQ_query_param_end
+      };
+      struct TALER_Amount amount_with_fee;
+      uint64_t s_f;
+      uint64_t s_v;
+      struct GNUNET_PQ_ResultSpec rs2[] = {
+        GNUNET_PQ_result_spec_uint64 ("s_v",
+                                      &s_v),
+        GNUNET_PQ_result_spec_uint64 ("s_f",
+                                      &s_f),
+        TALER_PQ_RESULT_SPEC_AMOUNT ("amount_with_fee",
+                                     &amount_with_fee),
+        GNUNET_PQ_result_spec_end
+      };
+      enum GNUNET_DB_QueryStatus qs;
+
+      qs = GNUNET_PQ_eval_prepared_singleton_select (
+        pg->conn,
+        "test_refund_full",
+        params,
+        rs2);
+      if (qs <= 0)
+      {
+        GNUNET_break (0);
+        rsc->status = GNUNET_SYSERR;
+        return;
+      }
+      /* normalize */
+      s_v += s_f / TALER_AMOUNT_FRAC_BASE;
+      s_f %= TALER_AMOUNT_FRAC_BASE;
+      full_refund = (s_v >= amount_with_fee.value) &&
+                    (s_f >= amount_with_fee.fraction);
+    }
     ret = rsc->cb (rsc->cb_cls,
                    rowid,
                    &denom_pub,
@@ -10728,6 +11062,7 @@ refunds_serial_helper_cb (void *cls,
                    &refund.details.merchant_sig,
                    &refund.details.h_contract_terms,
                    refund.details.rtransaction_id,
+                   full_refund,
                    &refund.details.refund_amount);
     GNUNET_PQ_cleanup_result (rs);
     if (GNUNET_OK != ret)
@@ -13129,6 +13464,9 @@ postgres_lookup_serial_by_table (void *cls,
   case TALER_EXCHANGEDB_RT_PURSE_REQUESTS:
     statement = "select_serial_by_table_purse_requests";
     break;
+  case TALER_EXCHANGEDB_RT_PURSE_REFUNDS:
+    statement = "select_serial_by_table_purse_refunds";
+    break;
   case TALER_EXCHANGEDB_RT_PURSE_MERGES:
     statement = "select_serial_by_table_purse_merges";
     break;
@@ -13337,6 +13675,10 @@ postgres_lookup_records_by_table (void *cls,
     statement = "select_above_serial_by_table_purse_requests";
     rh = &lrbt_cb_table_purse_requests;
     break;
+  case TALER_EXCHANGEDB_RT_PURSE_REFUNDS:
+    statement = "select_above_serial_by_table_purse_refunds";
+    rh = &lrbt_cb_table_purse_refunds;
+    break;
   case TALER_EXCHANGEDB_RT_PURSE_MERGES:
     statement = "select_above_serial_by_table_purse_merges";
     rh = &lrbt_cb_table_purse_merges;
@@ -13510,6 +13852,9 @@ postgres_insert_records_by_table (void *cls,
   case TALER_EXCHANGEDB_RT_PURSE_REQUESTS:
     rh = &irbt_cb_table_purse_requests;
     break;
+  case TALER_EXCHANGEDB_RT_PURSE_REFUNDS:
+    rh = &irbt_cb_table_purse_refunds;
+    break;
   case TALER_EXCHANGEDB_RT_PURSE_MERGES:
     rh = &irbt_cb_table_purse_merges;
     break;
@@ -15203,6 +15548,10 @@ libtaler_plugin_exchangedb_postgres_init (void *cls)
     = &postgres_select_deposits_above_serial_id;
   plugin->select_purse_deposits_above_serial_id
     = &postgres_select_purse_deposits_above_serial_id;
+  plugin->select_purse_refunds_above_serial_id
+    = &postgres_select_purse_refunds_above_serial_id;
+  plugin->select_purse_deposits_by_purse
+    = &postgres_select_purse_deposits_by_purse;
   plugin->select_refreshes_above_serial_id
     = &postgres_select_refreshes_above_serial_id;
   plugin->select_refunds_above_serial_id

src/exchangedb/shard-0001-part.sql

@@ -92,6 +92,9 @@ BEGIN
   PERFORM create_table_purse_requests(shard_suffix);
   PERFORM add_constraints_to_purse_requests_partition(shard_suffix);
 
+  PERFORM create_table_purse_refunds(shard_suffix);
+  PERFORM add_constraints_to_purse_refunds_partition(shard_suffix);
+
   PERFORM create_table_purse_merges(shard_suffix);
   PERFORM add_constraints_to_purse_merges_partition(shard_suffix);
 
@@ -224,6 +227,10 @@ BEGIN
     'DROP TABLE IF EXISTS %I CASCADE'
     ,'purse_requests_' || shard_suffix
   );
+  EXECUTE FORMAT(
+    'DROP TABLE IF EXISTS %I CASCADE'
+    ,'purse_refunds_' || shard_suffix
+  );
   EXECUTE FORMAT(
     'DROP TABLE IF EXISTS %I CASCADE'
     ,'purse_merges_' || shard_suffix

src/exchangedb/test_exchangedb.c

@@ -646,6 +646,7 @@ audit_deposit_cb (void *cls,
  * @param h_contract_terms hash of the proposal data in
  *                        the contract between merchant and customer
  * @param rtransaction_id refund transaction ID chosen by the merchant
+ * @param full_refund the deposit
  * @param amount_with_fee amount that was deposited including fee
  * @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
  */
@@ -658,6 +659,7 @@ audit_refund_cb (void *cls,
                  const struct TALER_MerchantSignatureP *merchant_sig,
                  const struct TALER_PrivateContractHashP *h_contract_terms,
                  uint64_t rtransaction_id,
+                 bool full_refund,
                  const struct TALER_Amount *amount_with_fee)
 {
   (void) cls;
@@ -669,6 +671,7 @@ audit_refund_cb (void *cls,
   (void) h_contract_terms;
   (void) rtransaction_id;
   (void) amount_with_fee;
+  (void) full_refund;
   auditor_row_cnt++;
   return GNUNET_OK;
 }

src/include/.gitignore

@@ -0,0 +1 @@
+taler_signatures.h

src/include/taler_auditordb_plugin.h

@@ -253,6 +253,11 @@ struct TALER_AUDITORDB_ProgressPointCoin
    */
   uint64_t last_purse_deposits_serial_id;
 
+  /**
+   * Serial ID of the last purse_refunds operation the auditor processed.
+   */
+  uint64_t last_purse_refunds_serial_id;
+
 };
 
 

src/include/taler_exchangedb_plugin.h

@@ -218,6 +218,7 @@ enum TALER_EXCHANGEDB_ReplicatedTable
   TALER_EXCHANGEDB_RT_EXTENSIONS,
   TALER_EXCHANGEDB_RT_EXTENSION_DETAILS,
   TALER_EXCHANGEDB_RT_PURSE_REQUESTS,
+  TALER_EXCHANGEDB_RT_PURSE_REFUNDS,
   TALER_EXCHANGEDB_RT_PURSE_MERGES,
   TALER_EXCHANGEDB_RT_PURSE_DEPOSITS,
   TALER_EXCHANGEDB_RT_ACCOUNT_MERGES,
@@ -495,6 +496,11 @@ struct TALER_EXCHANGEDB_TableData
       struct TALER_PurseContractSignatureP purse_sig;
     } purse_requests;
 
+    struct
+    {
+      struct TALER_PurseContractPublicKeyP purse_pub;
+    } purse_refunds;
+
     struct
     {
       uint64_t partner_serial_id;
@@ -1995,6 +2001,40 @@ typedef enum GNUNET_GenericReturnValue
   const struct TALER_DenominationPublicKey *denom_pub);
 
 
+/**
+ * Function called with details about purse refunds that have been made, with
+ * the goal of auditing the purse refund's execution.
+ *
+ * @param cls closure
+ * @param rowid unique serial ID for the deposit in our DB
+ * @param purse_pub public key of the refunded purse
+ * @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
+ */
+typedef enum GNUNET_GenericReturnValue
+(*TALER_EXCHANGEDB_PurseRefundCallback)(
+  void *cls,
+  uint64_t rowid,
+  const struct TALER_PurseContractPublicKeyP *purse_pub);
+
+
+/**
+ * Function called with details about purse refunds that have been made, with
+ * the goal of auditing the purse refund's execution.
+ *
+ * @param cls closure
+ * @param amount_with_fee amount of the deposit into the purse
+ * @param coin_pub coin that is to be refunded the @a given amount_with_fee
+ * @param denom_pub denomination of @a coin_pub
+ * @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
+ */
+typedef enum GNUNET_GenericReturnValue
+(*TALER_EXCHANGEDB_PurseRefundCoinCallback)(
+  void *cls,
+  const struct TALER_Amount *amount_with_fee,
+  const struct TALER_CoinSpendPublicKeyP *coin_pub,
+  const struct TALER_DenominationPublicKey *denom_pub);
+
+
 /**
  * Function called with details about coins that were melted,
  * with the goal of auditing the refresh's execution.
@@ -2198,6 +2238,7 @@ typedef void
  * @param merchant_sig signature of the merchant
  * @param h_contract_terms hash of the proposal data known to merchant and customer
  * @param rtransaction_id refund transaction ID chosen by the merchant
+ * @param full_refund true if the refunds total up to the entire value of the deposit
  * @param amount_with_fee amount that was deposited including fee
  * @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
  */
@@ -2211,6 +2252,7 @@ typedef enum GNUNET_GenericReturnValue
   const struct TALER_MerchantSignatureP *merchant_sig,
   const struct TALER_PrivateContractHashP *h_contract_terms,
   uint64_t rtransaction_id,
+  bool full_refund,
   const struct TALER_Amount *amount_with_fee);
 
 
@@ -4058,6 +4100,41 @@ struct TALER_EXCHANGEDB_Plugin
     void *cb_cls);
 
 
+  /**
+   * Select purse refunds above @a serial_id in monotonically increasing
+   * order.
+   *
+   * @param cls closure
+   * @param serial_id highest serial ID to exclude (select strictly larger)
+   * @param cb function to call on each result
+   * @param cb_cls closure for @a cb
+   * @return transaction status code
+   */
+  enum GNUNET_DB_QueryStatus
+  (*select_purse_refunds_above_serial_id)(
+    void *cls,
+    uint64_t serial_id,
+    TALER_EXCHANGEDB_PurseRefundCallback cb,
+    void *cb_cls);
+
+
+  /**
+   * Select coins deposited into a purse.
+   *
+   * @param cls closure
+   * @param purse_pub public key of the purse
+   * @param cb function to call on each result
+   * @param cb_cls closure for @a cb
+   * @return transaction status code
+   */
+  enum GNUNET_DB_QueryStatus
+  (*select_purse_deposits_by_purse)(
+    void *cls,
+    const struct TALER_PurseContractPublicKeyP *purse_pub,
+    TALER_EXCHANGEDB_PurseRefundCoinCallback cb,
+    void *cb_cls);
+
+
   /**
    * Select refresh sessions above @a serial_id in monotonically increasing
    * order.