taler-typescript-core

commit 6affddc50527a8a4176e334166bff6b63c646ca6
parent 054af1c13e7f09ebb25437e9a38b36db7c0cfc5e
Author: Florian Dold <dold@taler.net>
Date:   Thu, 20 Aug 2026 19:06:45 +0200

wallet-core: reject incomplete withdrawal batches

Diffstat:
M
packages/taler-wallet-core/src/withdraw.test.ts
 | 
17
++++++++++++++++-
M
packages/taler-wallet-core/src/withdraw.ts
 | 
22
++++++++++++++++++++++

2 files changed, 38 insertions(+), 1 deletion(-)
diff --git a/packages/taler-wallet-core/src/withdraw.test.ts b/packages/taler-wallet-core/src/withdraw.test.ts
@@ -30,7 +30,10 @@ import {
 } from "./db-common.js";
 import { WalletDenomination } from "./db-common.js";
 import { selectWithdrawalDenominations } from "./denomSelection.js";
-import { isWithdrawalFinalStatus } from "./withdraw.js";
+import {
+  isWithdrawalFinalStatus,
+  requireWithdrawalBatchCardinality,
+} from "./withdraw.js";
 
 test("every terminal withdrawal status ends final-state waits", () => {
   for (const status of [
@@ -54,6 +57,18 @@ test("every terminal withdrawal status ends final-state waits", () => {
   );
 });
 
+test("withdrawal batches require one signature per planchet", () => {
+  assert.doesNotThrow(() => requireWithdrawalBatchCardinality(2, 2));
+  assert.throws(
+    () => requireWithdrawalBatchCardinality(2, 1),
+    /returned 1 withdrawal signatures for 2 planchets/,
+  );
+  assert.throws(
+    () => requireWithdrawalBatchCardinality(2, 3),
+    /returned 3 withdrawal signatures for 2 planchets/,
+  );
+});
+
 test("withdrawal selection bug repro", (t) => {
   const amount = {
     currency: "KUDOS",
diff --git a/packages/taler-wallet-core/src/withdraw.ts b/packages/taler-wallet-core/src/withdraw.ts
@@ -1535,6 +1535,20 @@ interface WithdrawalBatchResult {
   batchResp: ExchangeWithdrawResponse;
 }
 
+export function requireWithdrawalBatchCardinality(
+  requestedCount: number,
+  responseCount: number,
+): void {
+  if (requestedCount === responseCount) {
+    return;
+  }
+  throw TalerError.fromDetail(
+    TalerErrorCode.WALLET_TRANSACTION_PROTOCOL_VIOLATION,
+    {},
+    `exchange returned ${responseCount} withdrawal signatures for ${requestedCount} planchets`,
+  );
+}
+
 /**
  * Transition a transaction from pending(ready)
  * into a pending(kyc|aml) state, in case KYC is required.
@@ -1717,6 +1731,10 @@ async function processPlanchetExchangeLegacyBatchRequest(
       resp,
       codecForExchangeLegacyWithdrawBatchResponse(),
     );
+    requireWithdrawalBatchCardinality(
+      requestCoinIdxs.length,
+      r.ev_sigs.length,
+    );
     return {
       coinIdxs: requestCoinIdxs,
       batchResp: { ev_sigs: r.ev_sigs.map((x) => x.ev_sig) },
@@ -1910,6 +1928,10 @@ async function processPlanchetExchangeBatchRequest(
         // Forbidden or any unexpected status: treated as an error below.
         throwUnexpectedRequestError(resp.response, resp.detail!);
     }
+    requireWithdrawalBatchCardinality(
+      requestCoinIdxs.length,
+      resp.body.ev_sigs.length,
+    );
     return {
       coinIdxs: requestCoinIdxs,
       batchResp: resp.body,