improve status codes returned in case of denomination key troubles

src/exchange/taler-exchange-httpd_deposit.c

@@ -250,6 +250,8 @@ verify_and_execute_deposit (struct MHD_Connection *connection,
   struct DepositContext dc;
   struct TEH_KS_StateHandle *mks;
   const struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dki;
+  enum TALER_ErrorCode ec;
+  unsigned int hc;
 
   /* check signature */
   dr.purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_DEPOSIT);
@@ -287,12 +289,15 @@ verify_and_execute_deposit (struct MHD_Connection *connection,
   }
   dki = TEH_KS_denomination_key_lookup_by_hash (mks,
                                                 &deposit->coin.denom_pub_hash,
-                                                TEH_KS_DKU_DEPOSIT);
+                                                TEH_KS_DKU_DEPOSIT,
+                                                &ec,
+                                                &hc);
   if (NULL == dki)
   {
     TEH_KS_release (mks);
-    return TEH_RESPONSE_reply_internal_db_error (connection,
+    return TEH_RESPONSE_reply_with_error (connection,
-                                                 TALER_EC_DEPOSIT_DB_DENOMINATION_KEY_UNKNOWN);
+                                          ec,
+                                          hc);
   }
   TALER_amount_ntoh (&dc.value,
                      &dki->issue.properties.value);
@@ -388,6 +393,7 @@ TEH_DEPOSIT_handler_deposit (struct TEH_RequestHandler *rh,
   json_t *wire;
   char *emsg;
   enum TALER_ErrorCode ec;
+  unsigned int hc;
   struct TALER_EXCHANGEDB_Deposit deposit;
   struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dki;
   struct TEH_KS_StateHandle *key_state;
@@ -497,16 +503,17 @@ TEH_DEPOSIT_handler_deposit (struct TEH_RequestHandler *rh,
   }
   dki = TEH_KS_denomination_key_lookup_by_hash (key_state,
                                                 &deposit.coin.denom_pub_hash,
-                                                TEH_KS_DKU_DEPOSIT);
+                                                TEH_KS_DKU_DEPOSIT,
+                                                &ec,
+                                                &hc);
   if (NULL == dki)
   {
-    /* FIXME: #3887: if DK was revoked, we might want to give a 403 and not a 404! */
     TEH_KS_release (key_state);
     TALER_LOG_WARNING ("Unknown denomination key in /deposit request\n");
     GNUNET_JSON_parse_free (spec);
-    return TEH_RESPONSE_reply_arg_unknown (connection,
+    return TEH_RESPONSE_reply_with_error (connection,
-                                           TALER_EC_DEPOSIT_DENOMINATION_KEY_UNKNOWN,
+                                          ec,
-                                           "denom_pub");
+                                          hc);
   }
   TALER_amount_ntoh (&deposit.deposit_fee,
                      &dki->issue.properties.fee_deposit);

src/exchange/taler-exchange-httpd_keystate.c

@@ -1954,6 +1954,8 @@ TEH_KS_acquire_ (struct GNUNET_TIME_Absolute now,
  * @param key_state state to look in
  * @param denom_pub_hash hash of denomination public key
  * @param use purpose for which the key is being located
+ * @param ec[out] set to the error code, in case the operation failed
+ * @param hc[out] set to the HTTP status code to use
  * @return the denomination key issue,
  *         or NULL if denom_pub could not be found (or is not valid at this time for the given @a use)
  */
@@ -1962,7 +1964,9 @@ TEH_KS_denomination_key_lookup_by_hash (const struct
                                         TEH_KS_StateHandle *key_state,
                                         const struct
                                         GNUNET_HashCode *denom_pub_hash,
-                                        enum TEH_KS_DenominationKeyUse use)
+                                        enum TEH_KS_DenominationKeyUse use,
+                                        enum TALER_ErrorCode *ec,
+                                        unsigned int *hc)
 {
   struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dki;
   struct GNUNET_TIME_Absolute now;
@@ -1976,7 +1980,25 @@ TEH_KS_denomination_key_lookup_by_hash (const struct
     dki = GNUNET_CONTAINER_multihashmap_get (key_state->revoked_map,
                                              denom_pub_hash);
   if (NULL == dki)
+  {
+    *hc = MHD_HTTP_NOT_FOUND;
+    switch (use)
+    {
+    case TEH_KS_DKU_PAYBACK:
+      *ec = TALER_EC_PAYBACK_DENOMINATION_KEY_UNKNOWN;
+      break;
+    case TEH_KS_DKU_ZOMBIE:
+      *ec = TALER_EC_REFRESH_PAYBACK_DENOMINATION_KEY_NOT_FOUND;
+      break;
+    case TEH_KS_DKU_WITHDRAW:
+      *ec = TALER_EC_WITHDRAW_DENOMINATION_KEY_NOT_FOUND;
+      break;
+    case TEH_KS_DKU_DEPOSIT:
+      *ec = TALER_EC_DEPOSIT_DENOMINATION_KEY_UNKNOWN;
+      break;
+    }
     return NULL;
+  }
   now = GNUNET_TIME_absolute_get ();
   if (now.abs_value_us <
       GNUNET_TIME_absolute_ntoh (dki->issue.properties.start).abs_value_us)
@@ -1984,6 +2006,22 @@ TEH_KS_denomination_key_lookup_by_hash (const struct
     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                 "Not returning DKI for %s, as start time is in the future\n",
                 GNUNET_h2s (denom_pub_hash));
+    *hc = MHD_HTTP_PRECONDITION_FAILED;
+    switch (use)
+    {
+    case TEH_KS_DKU_PAYBACK:
+      *ec = TALER_EC_PAYBACK_DENOMINATION_VALIDITY_IN_FUTURE;
+      break;
+    case TEH_KS_DKU_ZOMBIE:
+      *ec = TALER_EC_REFRESH_PAYBACK_DENOMINATION_VALIDITY_IN_FUTURE;
+      break;
+    case TEH_KS_DKU_WITHDRAW:
+      *ec = TALER_EC_WITHDRAW_VALIDITY_IN_FUTURE;
+      break;
+    case TEH_KS_DKU_DEPOSIT:
+      *ec = TALER_EC_DEPOSIT_DENOMINATION_VALIDITY_IN_FUTURE;
+      break;
+    }
     return NULL;
   }
   now = GNUNET_TIME_absolute_get ();
@@ -1997,6 +2035,8 @@ TEH_KS_denomination_key_lookup_by_hash (const struct
       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                   "Not returning DKI for %s, as time to create coins has passed\n",
                   GNUNET_h2s (denom_pub_hash));
+      *ec = TALER_EC_WITHDRAW_VALIDITY_IN_PAST;
+      *hc = MHD_HTTP_GONE;
       return NULL;
     }
     if (NULL == dki->denom_priv.rsa_private_key)
@@ -2004,6 +2044,8 @@ TEH_KS_denomination_key_lookup_by_hash (const struct
       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                   "Not returning DKI of %s for WITHDRAW operation as we lack the private key, even though the withdraw period did not yet expire!\n",
                   GNUNET_h2s (denom_pub_hash));
+      *ec = TALER_EC_DENOMINATION_KEY_LOST;
+      *hc = MHD_HTTP_SERVICE_UNAVAILABLE;
       return NULL;
     }
     break;
@@ -2015,6 +2057,8 @@ TEH_KS_denomination_key_lookup_by_hash (const struct
       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                   "Not returning DKI for %s, as time to spend coin has passed\n",
                   GNUNET_h2s (denom_pub_hash));
+      *ec = TALER_EC_DEPOSIT_DENOMINATION_EXPIRED;
+      *hc = MHD_HTTP_GONE;
       return NULL;
     }
     break;
@@ -2026,6 +2070,8 @@ TEH_KS_denomination_key_lookup_by_hash (const struct
       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                   "Not returning DKI for %s, as time to payback coin has passed\n",
                   GNUNET_h2s (denom_pub_hash));
+      *ec = TALER_EC_REFRESH_PAYBACK_DENOMINATION_EXPIRED;
+      *hc = MHD_HTTP_GONE;
       return NULL;
     }
     break;
@@ -2037,6 +2083,8 @@ TEH_KS_denomination_key_lookup_by_hash (const struct
       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                   "Not returning DKI for %s, as legal expiration of coin has passed\n",
                   GNUNET_h2s (denom_pub_hash));
+      *ec = TALER_EC_REFRESH_ZOMBIE_DENOMINATION_EXPIRED;
+      *hc = MHD_HTTP_GONE;
       return NULL;
     }
     break;

src/exchange/taler-exchange-httpd_keystate.h

@@ -129,6 +129,8 @@ enum TEH_KS_DenominationKeyUse
  * @param key_state state to look in
  * @param denom_pub_hash hash of denomination public key
  * @param use purpose for which the key is being located
+ * @param ec[out] set to the error code, in case the operation failed
+ * @param hc[out] set to the HTTP status code to use
  * @return the denomination key issue,
  *         or NULL if denom_pub could not be found (or is not valid at this time for the given @a use)
  */
@@ -137,7 +139,9 @@ TEH_KS_denomination_key_lookup_by_hash (const struct
                                         TEH_KS_StateHandle *key_state,
                                         const struct
                                         GNUNET_HashCode *denom_pub_hash,
-                                        enum TEH_KS_DenominationKeyUse use);
+                                        enum TEH_KS_DenominationKeyUse use,
+                                        enum TALER_ErrorCode *ec,
+                                        unsigned int *hc);
 
 
 /**

src/exchange/taler-exchange-httpd_payback.c

@@ -429,6 +429,8 @@ verify_and_execute_payback (struct MHD_Connection *connection,
   struct GNUNET_HashCode c_hash;
   char *coin_ev;
   size_t coin_ev_size;
+  enum TALER_ErrorCode ec;
+  unsigned int hc;
 
   /* check denomination exists and is in payback mode */
   key_state = TEH_KS_acquire (GNUNET_TIME_absolute_get ());
@@ -441,15 +443,17 @@ verify_and_execute_payback (struct MHD_Connection *connection,
   }
   dki = TEH_KS_denomination_key_lookup_by_hash (key_state,
                                                 &coin->denom_pub_hash,
-                                                TEH_KS_DKU_PAYBACK);
+                                                TEH_KS_DKU_PAYBACK,
+                                                &ec,
+                                                &hc);
   if (NULL == dki)
   {
     TEH_KS_release (key_state);
     TALER_LOG_WARNING (
       "Denomination key in /payback request not in payback mode\n");
-    return TEH_RESPONSE_reply_arg_unknown (connection,
+    return TEH_RESPONSE_reply_with_error (connection,
-                                           TALER_EC_PAYBACK_DENOMINATION_KEY_UNKNOWN,
+                                          ec,
-                                           "denom_pub");
+                                          hc);
   }
   TALER_amount_ntoh (&pc.value,
                      &dki->issue.properties.value);

src/exchange/taler-exchange-httpd_refresh_melt.c

@@ -447,6 +447,8 @@ TEH_REFRESH_handler_refresh_melt (struct TEH_RequestHandler *rh,
   json_t *root;
   struct RefreshMeltContext rmc;
   int res;
+  unsigned int hc;
+  enum TALER_ErrorCode ec;
   struct TEH_KS_StateHandle *key_state;
   struct GNUNET_JSON_Specification spec[] = {
     GNUNET_JSON_spec_fixed_auto ("coin_pub",
@@ -501,7 +503,9 @@ TEH_REFRESH_handler_refresh_melt (struct TEH_RequestHandler *rh,
   rmc.dki = TEH_KS_denomination_key_lookup_by_hash (key_state,
                                                     &rmc.refresh_session.coin.
                                                     denom_pub_hash,
-                                                    TEH_KS_DKU_DEPOSIT);
+                                                    TEH_KS_DKU_DEPOSIT,
+                                                    &ec,
+                                                    &hc);
   /* Consider case that denomination was revoked but
      this coin was already seen and thus refresh is OK. */
   if (NULL == rmc.dki)
@@ -511,7 +515,9 @@ TEH_REFRESH_handler_refresh_melt (struct TEH_RequestHandler *rh,
     dki = TEH_KS_denomination_key_lookup_by_hash (key_state,
                                                   &rmc.refresh_session.coin.
                                                   denom_pub_hash,
-                                                  TEH_KS_DKU_PAYBACK);
+                                                  TEH_KS_DKU_PAYBACK,
+                                                  &ec,
+                                                  &hc);
     if (NULL != dki)
     {
       struct TALER_CoinPublicInfo coin_info;
@@ -547,7 +553,9 @@ TEH_REFRESH_handler_refresh_melt (struct TEH_RequestHandler *rh,
     dki = TEH_KS_denomination_key_lookup_by_hash (key_state,
                                                   &rmc.refresh_session.coin.
                                                   denom_pub_hash,
-                                                  TEH_KS_DKU_ZOMBIE);
+                                                  TEH_KS_DKU_ZOMBIE,
+                                                  &ec,
+                                                  &hc);
     if (NULL != dki)
     {
       rmc.dki = dki;
@@ -558,9 +566,9 @@ TEH_REFRESH_handler_refresh_melt (struct TEH_RequestHandler *rh,
   if (NULL == rmc.dki)
   {
     TALER_LOG_WARNING ("Unknown denomination key in /refresh/melt request\n");
-    res = TEH_RESPONSE_reply_arg_unknown (connection,
+    res = TEH_RESPONSE_reply_with_error (connection,
-                                          TALER_EC_REFRESH_MELT_DENOMINATION_KEY_NOT_FOUND,
+                                         ec,
-                                          "denom_pub");
+                                         hc);
     goto cleanup;
   }
 

src/exchange/taler-exchange-httpd_refresh_reveal.c

@@ -610,6 +610,8 @@ handle_refresh_reveal_json (struct MHD_Connection *connection,
                                      &dki_h[i]),
         GNUNET_JSON_spec_end ()
       };
+      unsigned int hc;
+      enum TALER_ErrorCode ec;
 
       res = TEH_PARSE_json_array (connection,
                                   new_denoms_h_json,
@@ -623,13 +625,15 @@ handle_refresh_reveal_json (struct MHD_Connection *connection,
       }
       dkis[i] = TEH_KS_denomination_key_lookup_by_hash (key_state,
                                                         &dki_h[i],
-                                                        TEH_KS_DKU_WITHDRAW);
+                                                        TEH_KS_DKU_WITHDRAW,
+                                                        &ec,
+                                                        &hc);
       if (NULL == dkis[i])
       {
         TEH_KS_release (key_state);
-        return TEH_RESPONSE_reply_arg_invalid (connection,
+        return TEH_RESPONSE_reply_with_error (connection,
-                                               TALER_EC_REFRESH_REVEAL_FRESH_DENOMINATION_KEY_NOT_FOUND,
+                                              ec,
-                                               "new_denoms_h");
+                                              hc);
       }
       GNUNET_assert (NULL != dkis[i]->denom_priv.rsa_private_key);
     }

src/exchange/taler-exchange-httpd_refund.c

@@ -161,6 +161,8 @@ refund_transaction (void *cls,
   int deposit_found;
   int refund_found;
   int fee_cmp;
+  unsigned int hc;
+  enum TALER_ErrorCode ec;
 
   dep = NULL;
   ref = NULL;
@@ -354,7 +356,9 @@ refund_transaction (void *cls,
   }
   dki = TEH_KS_denomination_key_lookup_by_hash (mks,
                                                 &dep->coin.denom_pub_hash,
-                                                TEH_KS_DKU_DEPOSIT);
+                                                TEH_KS_DKU_DEPOSIT,
+                                                &ec,
+                                                &hc);
   if (NULL == dki)
   {
     /* DKI not found, but we do have a coin with this DK in our database;
@@ -363,9 +367,9 @@ refund_transaction (void *cls,
     TEH_KS_release (mks);
     TEH_plugin->free_coin_transaction_list (TEH_plugin->cls,
                                             tl);
-    *mhd_ret = TEH_RESPONSE_reply_internal_error (connection,
+    *mhd_ret = TEH_RESPONSE_reply_with_error (connection,
-                                                  TALER_EC_REFUND_DENOMINATION_KEY_NOT_FOUND,
+                                              ec,
-                                                  "denomination key not found");
+                                              hc);
     return GNUNET_DB_STATUS_HARD_ERROR;
   }
   TALER_amount_ntoh (&expect_fee,

src/exchange/taler-exchange-httpd_reserve_withdraw.c

@@ -365,6 +365,8 @@ TEH_RESERVE_handler_reserve_withdraw (struct TEH_RequestHandler *rh,
   json_t *root;
   int res;
   int mhd_ret;
+  unsigned int hc;
+  enum TALER_ErrorCode ec;
   struct TALER_Amount amount;
   struct TALER_Amount fee_withdraw;
   struct GNUNET_JSON_Specification spec[] = {
@@ -407,14 +409,16 @@ TEH_RESERVE_handler_reserve_withdraw (struct TEH_RequestHandler *rh,
   }
   wc.dki = TEH_KS_denomination_key_lookup_by_hash (wc.key_state,
                                                    &wc.denom_pub_hash,
-                                                   TEH_KS_DKU_WITHDRAW);
+                                                   TEH_KS_DKU_WITHDRAW,
+                                                   &ec,
+                                                   &hc);
   if (NULL == wc.dki)
   {
     GNUNET_JSON_parse_free (spec);
     TEH_KS_release (wc.key_state);
-    return TEH_RESPONSE_reply_arg_unknown (connection,
+    return TEH_RESPONSE_reply_with_error (connection,
-                                           TALER_EC_WITHDRAW_DENOMINATION_KEY_NOT_FOUND,
+                                          ec,
-                                           "denom_pub");
+                                          hc);
   }
   GNUNET_assert (NULL != wc.dki->denom_priv.rsa_private_key);
   TALER_amount_ntoh (&amount,

src/exchange/taler-exchange-httpd_responses.c

@@ -361,6 +361,26 @@ TEH_RESPONSE_reply_internal_error (struct MHD_Connection *connection,
 }
 
 
+/**
+ * Send a response indicating an error.
+ *
+ * @param connection the MHD connection to use
+ * @param ec error code uniquely identifying the error
+ * @param http_status HTTP status code to use
+ * @return a MHD result code
+ */
+int
+TEH_RESPONSE_reply_with_error (struct MHD_Connection *connection,
+                               enum TALER_ErrorCode ec,
+                               unsigned int http_status)
+{
+  return TEH_RESPONSE_reply_json_pack (connection,
+                                       http_status,
+                                       "{s:I}",
+                                       "code", (json_int_t) ec);
+}
+
+
 /**
  * Send a response indicating an external error.
  *

src/exchange/taler-exchange-httpd_responses.h

@@ -170,6 +170,20 @@ TEH_RESPONSE_reply_internal_error (struct MHD_Connection *connection,
                                    const char *hint);
 
 
+/**
+ * Send a response indicating an error.
+ *
+ * @param connection the MHD connection to use
+ * @param ec error code uniquely identifying the error
+ * @param http_status HTTP status code to use
+ * @return a MHD result code
+ */
+int
+TEH_RESPONSE_reply_with_error (struct MHD_Connection *connection,
+                               enum TALER_ErrorCode ec,
+                               unsigned int http_status);
+
+
 /**
  * Send a response indicating an external error.
  *

src/include/taler_error_codes.h

@@ -297,6 +297,29 @@ enum TALER_ErrorCode
    */
   TALER_EC_WITHDRAW_RESERVE_HISTORY_IMPOSSIBLE = 1113,
 
+  /**
+   * Validity period of the coin to be withdrawn
+   * is in the future.  Returned with an HTTP
+   * status of #MHD_HTTP_PRECONDITION_FAILED.
+   */
+  TALER_EC_WITHDRAW_VALIDITY_IN_FUTURE = 1114,
+
+  /**
+   * Withdraw period of the coin to be withdrawn
+   * is in the past.  Returned with an HTTP
+   * status of #MHD_HTTP_GONE.
+   */
+  TALER_EC_WITHDRAW_VALIDITY_IN_PAST = 1115,
+
+  /**
+   * The private key associated with the denomination
+   * key is unknown to the server, possibly because
+   * the key was revoked.  Returned with an HTTP
+   * status of #MHD_HTTP_SERVICE_UNAVAILABLE.
+   */
+  TALER_EC_DENOMINATION_KEY_LOST = 1116,
+
+
   /**
    * The exchange failed to obtain the transaction history of the
    * given reserve from the database.
@@ -453,6 +476,20 @@ enum TALER_ErrorCode
    */
   TALER_EC_DEPOSIT_INVALID_TIMESTAMP = 1218,
 
+  /**
+   * Validity period of the denomination key
+   * is in the future.  Returned with an HTTP
+   * status of #MHD_HTTP_PRECONDITION_FAILED.
+   */
+  TALER_EC_DEPOSIT_DENOMINATION_VALIDITY_IN_FUTURE = 1219,
+
+  /**
+   * Denomination key of the coin is past the
+   * deposit deadline.  Returned with an HTTP
+   * status of #MHD_HTTP_GONE.
+   */
+  TALER_EC_DEPOSIT_DENOMINATION_EXPIRED = 1220,
+
 
   /**
    * The respective coin did not have sufficient residual value
@@ -531,6 +568,35 @@ enum TALER_ErrorCode
    */
   TALER_EC_REFRESH_MELT_COIN_EXPIRED_NO_ZOMBIE = 1309,
 
+  /**
+   * The exchange is unaware of the denomination key that was
+   * used to sign the melted zombie coin.  This response is provided
+   * with HTTP status code MHD_HTTP_NOT_FOUND.
+   */
+  TALER_EC_REFRESH_PAYBACK_DENOMINATION_KEY_NOT_FOUND = 1301,
+
+  /**
+   * Validity period of the denomination key
+   * is in the future.  Returned with an HTTP
+   * status of #MHD_HTTP_PRECONDITION_FAILED.
+   */
+  TALER_EC_REFRESH_PAYBACK_DENOMINATION_VALIDITY_IN_FUTURE = 1301,
+
+  /**
+   * Denomination key of the coin is past the
+   * deposit deadline.  Returned with an HTTP
+   * status of #MHD_HTTP_GONE.
+   */
+  TALER_EC_REFRESH_PAYBACK_DENOMINATION_EXPIRED = 1302,
+
+  /**
+   * Denomination key of the coin is past the
+   * deposit deadline.  Returned with an HTTP
+   * status of #MHD_HTTP_GONE.
+   */
+  TALER_EC_REFRESH_ZOMBIE_DENOMINATION_EXPIRED = 1303,
+
+
   /**
    * The provided transfer keys do not match up with the
    * original commitment.  Information about the original
@@ -921,7 +987,15 @@ enum TALER_ErrorCode
    * This response is provided with an HTTP status code of
    * MHD_HTTP_INTERNAL_SERVER_ERROR
    */
-  TALER_EC_PAYBACK_COIN_BALANCE_NEGATIVE = 1857,
+  TALER_EC_PAYBACK_COIN_BALANCE_NEGATIVE = 1859,
+
+  /**
+   * Validity period of the denomination key
+   * is in the future.  Returned with an HTTP
+   * status of #MHD_HTTP_PRECONDITION_FAILED.
+   */
+  TALER_EC_PAYBACK_DENOMINATION_VALIDITY_IN_FUTURE = 1860,
+
 
   /**
    * The "have" parameter was not a natural number.