exchange

commit abf2f890754bcf1d6c11fc4b2b41adf4c18a70d7
parent 32531d99f47b6b390c1804a2a7d58d5fc2c6d9ae
Author: Christian Grothoff <christian@grothoff.org>
Date:   Sun, 11 Oct 2026 14:19:21 +0200

return meaningful coin-based hint, check refund_fee is covered by refund_amount

Diffstat:
M
src/exchange/taler-exchange-httpd_post-coins-COIN_PUB-refund.c
 | 
26
++++++++++++++++++++------

1 file changed, 20 insertions(+), 6 deletions(-)
diff --git a/src/exchange/taler-exchange-httpd_post-coins-COIN_PUB-refund.c b/src/exchange/taler-exchange-httpd_post-coins-COIN_PUB-refund.c
@@ -257,18 +257,18 @@ verify_and_execute_refund (struct MHD_Connection *connection,
     case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
       {
         enum MHD_Result res;
-        char *dhs;
+        char *cps;
 
         GNUNET_break_op (0);
-        dhs = GNUNET_STRINGS_data_to_string_alloc (
-          &refund->coin.denom_pub_hash,
-          sizeof (refund->coin.denom_pub_hash));
+        cps = GNUNET_STRINGS_data_to_string_alloc (
+          &refund->coin.coin_pub,
+          sizeof (refund->coin.coin_pub));
         res = TALER_MHD_reply_with_error (
           connection,
           MHD_HTTP_NOT_FOUND,
           TALER_EC_EXCHANGE_REFUND_COIN_NOT_FOUND,
-          dhs);
-        GNUNET_free (dhs);
+          cps);
+        GNUNET_free (cps);
         return res;
       }
     case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
@@ -296,6 +296,20 @@ verify_and_execute_refund (struct MHD_Connection *connection,
     rctx.deposit_fee = dk->meta.fees.deposit;
   }
 
+  /* The refund fee is subtracted from the refunded amount, so the
+     client-chosen amount must cover it. */
+  if (0 >
+      TALER_amount_cmp (&refund->details.refund_amount,
+                        &refund->details.refund_fee))
+  {
+    GNUNET_break_op (0);
+    return TALER_MHD_reply_with_error (
+      connection,
+      MHD_HTTP_BAD_REQUEST,
+      TALER_EC_EXCHANGE_REFUND_FEE_ABOVE_AMOUNT,
+      NULL);
+  }
+
   /* Finally run the actual transaction logic */
   {
     enum MHD_Result mhd_ret;