1 files changed, 18 insertions, 1 deletions
diff --git a/packages/taler-wallet-core/src/operations/exchanges.ts b/packages/taler-wallet-core/src/operations/exchanges.ts
index 69f708364..bf7d4424a 100644
--- a/packages/taler-wallet-core/src/operations/exchanges.ts
+++ b/packages/taler-wallet-core/src/operations/exchanges.ts
@@ -821,6 +821,10 @@ export async function waitExchangeEntryUpdated(
  *
  * If an exchange entry for the database doesn't exist in the
  * DB, it will be added ephemerally.
+ *
+ * If the expectedMasterPub is given and does not match the actual
+ * master pub, an exception will be thrown.  However, the exchange
+ * will still have been added as an ephemeral exchange entry.
  */
 export async function fetchFreshExchange(
   ws: InternalWalletState,
@@ -828,6 +832,7 @@ export async function fetchFreshExchange(
   options: {
     cancellationToken?: CancellationToken;
     forceUpdate?: boolean;
+    expectedMasterPub?: string;
   } = {},
 ): Promise<{
   exchange: ExchangeEntryRecord;
@@ -837,7 +842,19 @@ export async function fetchFreshExchange(
   await startUpdateExchangeEntry(ws, canonUrl, {
     forceUpdate: options.forceUpdate,
   });
-  return waitExchangeEntryUpdated(ws, canonUrl, options.cancellationToken);
+  const res = await waitExchangeEntryUpdated(
+    ws,
+    canonUrl,
+    options.cancellationToken,
+  );
+  if (options.expectedMasterPub) {
+    if (res.exchangeDetails.masterPublicKey !== options.expectedMasterPub) {
+      throw Error(
+        "public key of the exchange does not match expected public key",
+      );
+    }
+  }
+  return res;
 }
 
 /**