new configuration option: wallet balance threshold

src/exchange/exchange.conf

@@ -87,6 +87,10 @@ PRIVACY_ETAG = 0
 # Set to "OAUTH2" to use OAuth 2.0 for KYC authorization.
 KYC_MODE = NONE
 
+# Balance threshold above which wallets are told
+# to undergo a KYC check at the exchange. Optional,
+# if not given there is no limit.
+# KYC_WALLET_BALANCE_LIMIT = 150:CURRENCY
 
 [exchange-kyc-oauth2]
 

src/exchange/taler-exchange-httpd.c

@@ -1279,6 +1279,35 @@ exchange_serve_process_config (void)
                                "CURRENCY");
     return GNUNET_SYSERR;
   }
+  if (TEH_KYC_NONE != TEH_kyc_config.mode)
+  {
+    if (GNUNET_YES ==
+        GNUNET_CONFIGURATION_have_value (TEH_cfg,
+                                         "exchange",
+                                         "KYC_WALLET_BALANCE_LIMIT"))
+    {
+      if ( (GNUNET_OK !=
+            TALER_config_get_amount (TEH_cfg,
+                                     "exchange",
+                                     "KYC_WALLET_BALANCE_LIMIT",
+                                     &TEH_kyc_config.wallet_balance_limit)) ||
+           (0 != strcasecmp (TEH_currency,
+                             TEH_kyc_config.wallet_balance_limit.currency)) )
+      {
+        GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
+                                   "exchange",
+                                   "KYC_WALLET_BALANCE_LIMIT",
+                                   "valid amount expected");
+        return GNUNET_SYSERR;
+      }
+    }
+    else
+    {
+      memset (&TEH_kyc_config.wallet_balance_limit,
+              0,
+              sizeof (TEH_kyc_config.wallet_balance_limit));
+    }
+  }
   {
     char *master_public_key_str;
 

src/exchange/taler-exchange-httpd.h

@@ -64,6 +64,14 @@ struct TEH_KycOptions
    */
   struct TALER_Amount withdraw_limit;
 
+  /**
+   * Maximum balance a wallet can hold without
+   * needing KYC.
+   * Only valid if @e mode is not #TEH_KYC_NONE and
+   * if the amount specified is valid.
+   */
+  struct TALER_Amount wallet_balance_limit;
+
   /**
    * Time period over which @e withdraw_limit applies.
    * Only valid if @e mode is not #TEH_KYC_NONE.

src/exchange/taler-exchange-httpd_keys.c

@@ -1473,6 +1473,18 @@ create_krd (struct TEH_KeyStateHandle *ksh,
     GNUNET_JSON_pack_data_auto ("eddsa_sig",
                                 &exchange_sig));
   GNUNET_assert (NULL != keys);
+  if ( (TEH_KYC_NONE != TEH_kyc_config.mode) &&
+       (GNUNET_OK ==
+        TALER_amount_is_valid (&TEH_kyc_config.wallet_balance_limit)) )
+  {
+    GNUNET_assert (
+      0 ==
+      json_object_set_new (
+        keys,
+        "wallet_balance_limit_without_kyc",
+        TALER_JSON_from_amount (
+          &TEH_kyc_config.wallet_balance_limit)));
+  }
 
   {
     char *keys_json;

src/include/taler_exchange_service.h

@@ -264,6 +264,12 @@ struct TALER_EXCHANGE_Keys
    */
   struct GNUNET_TIME_Relative reserve_closing_delay;
 
+  /**
+   * Maximum amount a wallet is allowed to hold from
+   * this exchange before it must undergo a KYC check.
+   */
+  struct TALER_Amount wallet_balance_limit_without_kyc;
+
   /**
    * Timestamp indicating the /keys generation.
    */

src/lib/exchange_api_handle.c

@@ -685,8 +685,6 @@ decode_keys_json (const json_t *resp_obj,
                                  &sig),
     GNUNET_JSON_spec_fixed_auto ("eddsa_pub",
                                  &pub),
-    /* sig and pub must be first, as we skip those if
-       check_sig is false! */
     GNUNET_JSON_spec_fixed_auto ("master_public_key",
                                  &key_data->master_pub),
     TALER_JSON_spec_absolute_time ("list_issue_date",
@@ -695,6 +693,10 @@ decode_keys_json (const json_t *resp_obj,
                                    &key_data->reserve_closing_delay),
     GNUNET_JSON_spec_string ("currency",
                              &currency),
+    GNUNET_JSON_spec_mark_optional (
+      TALER_JSON_spec_amount ("wallet_balance_limit_without_kyc",
+                              currency,
+                              &key_data->wallet_balance_limit_without_kyc)),
     GNUNET_JSON_spec_end ()
   };