wallet-core: implement and test lost flag for denominations

5 files changed, 58 insertions, 3 deletions

diff --git a/packages/taler-wallet-core/src/db.ts b/packages/taler-wallet-core/src/db.ts
index 14621c2d5..b59efe034 100644
--- a/packages/taler-wallet-core/src/db.ts
+++ b/packages/taler-wallet-core/src/db.ts
@@ -486,6 +486,13 @@ export interface DenominationRecord {
   isRevoked: boolean;
 
   /**
+   * If set to true, the exchange announced that the private key for this
+   * denomination is lost.  Thus it can't be used to sign new coins
+   * during withdrawal/refresh/..., but the coins can still be spent.
+   */
+  isLost?: boolean;
+
+  /**
    * Base URL of the exchange.
    */
   exchangeBaseUrl: string;
diff --git a/packages/taler-wallet-core/src/denominations.ts b/packages/taler-wallet-core/src/denominations.ts
index a539918de..d41307d5d 100644
--- a/packages/taler-wallet-core/src/denominations.ts
+++ b/packages/taler-wallet-core/src/denominations.ts
@@ -24,7 +24,6 @@ import {
   AmountString,
   DenominationInfo,
   Duration,
-  durationFromSpec,
   FeeDescription,
   FeeDescriptionPair,
   TalerProtocolTimestamp,
@@ -471,10 +470,10 @@ export function isWithdrawableDenom(
   } else {
     lastPossibleWithdraw = AbsoluteTime.subtractDuraction(
       withdrawExpire,
-      durationFromSpec({ minutes: 5 }),
+      Duration.fromSpec({ minutes: 5 }),
     );
   }
   const remaining = Duration.getRemaining(lastPossibleWithdraw, now);
   const stillOkay = remaining.d_ms !== 0;
-  return started && stillOkay && !d.isRevoked && d.isOffered;
+  return started && stillOkay && !d.isRevoked && d.isOffered && !d.isLost;
 }
diff --git a/packages/taler-wallet-core/src/exchanges.ts b/packages/taler-wallet-core/src/exchanges.ts
index 335caff62..c44178de8 100644
--- a/packages/taler-wallet-core/src/exchanges.ts
+++ b/packages/taler-wallet-core/src/exchanges.ts
@@ -779,6 +779,7 @@ async function downloadExchangeKeysInfo(
             exchangeMasterPub: exchangeKeysJsonUnchecked.master_public_key,
             isOffered: true,
             isRevoked: false,
+            isLost: denomIn.lost ?? false,
             value: Amounts.stringify(value),
             currency: value.currency,
             stampExpireDeposit: timestampProtocolToDb(
@@ -1432,6 +1433,16 @@ export async function updateExchangeFromUrlHandler(
         ]);
         if (oldDenom) {
           // FIXME: Do consistency check, report to auditor if necessary.
+          // See https://bugs.taler.net/n/8594
+
+          // Mark lost denominations as lost.
+          if (currentDenom.isLost && !oldDenom.isLost) {
+            logger.warn(
+              `marking denomination ${currentDenom.denomPubHash} of ${exchangeBaseUrl} as lost`,
+            );
+            oldDenom.isLost = true;
+            await tx.denominations.put(currentDenom);
+          }
         } else {
           await tx.denominations.put(currentDenom);
         }
diff --git a/packages/taler-wallet-core/src/wallet-api-types.ts b/packages/taler-wallet-core/src/wallet-api-types.ts
index ace702e88..4f4b24b62 100644
--- a/packages/taler-wallet-core/src/wallet-api-types.ts
+++ b/packages/taler-wallet-core/src/wallet-api-types.ts
@@ -117,6 +117,8 @@ import {
   StoredBackupList,
   TestPayArgs,
   TestPayResult,
+  TestingGetDenomStatsRequest,
+  TestingGetDenomStatsResponse,
   TestingListTasksForTransactionRequest,
   TestingListTasksForTransactionsResponse,
   TestingSetTimetravelRequest,
@@ -255,6 +257,7 @@ export enum WalletApiOperation {
   RemoveGlobalCurrencyAuditor = "removeGlobalCurrencyAuditor",
   ListAssociatedRefreshes = "listAssociatedRefreshes",
   TestingListTaskForTransaction = "testingListTasksForTransaction",
+  TestingGetDenomStats = "testingGetDenomStats",
 }
 
 // group: Initialization
@@ -1114,6 +1117,15 @@ export type TestingWaitTransactionStateOp = {
 };
 
 /**
+ * Get stats about an exchange denomination.
+ */
+export type TestingGetDenomStatsOp = {
+  op: WalletApiOperation.TestingGetDenomStats;
+  request: TestingGetDenomStatsRequest;
+  response: TestingGetDenomStatsResponse;
+};
+
+/**
  * Set a coin as (un-)suspended.
  * Suspended coins won't be used for payments.
  */
@@ -1238,6 +1250,7 @@ export type WalletOperations = {
   [WalletApiOperation.RemoveGlobalCurrencyExchange]: RemoveGlobalCurrencyExchangeOp;
   [WalletApiOperation.ListAssociatedRefreshes]: ListAssociatedRefreshesOp;
   [WalletApiOperation.TestingListTaskForTransaction]: TestingListTasksForTransactionOp;
+  [WalletApiOperation.TestingGetDenomStats]: TestingGetDenomStatsOp;
 };
 
 export type WalletCoreRequestType<
diff --git a/packages/taler-wallet-core/src/wallet.ts b/packages/taler-wallet-core/src/wallet.ts
index 8c9eee009..46f58ec81 100644
--- a/packages/taler-wallet-core/src/wallet.ts
+++ b/packages/taler-wallet-core/src/wallet.ts
@@ -57,6 +57,7 @@ import {
   TalerErrorCode,
   TalerProtocolTimestamp,
   TalerUriAction,
+  TestingGetDenomStatsResponse,
   TestingListTasksForTransactionsResponse,
   TestingWaitTransactionRequest,
   TimerAPI,
@@ -126,6 +127,7 @@ import {
   codecForStartRefundQueryRequest,
   codecForSuspendTransaction,
   codecForTestPayArgs,
+  codecForTestingGetDenomStatsRequest,
   codecForTestingListTasksForTransactionRequest,
   codecForTestingSetTimetravelRequest,
   codecForTransactionByIdRequest,
@@ -799,6 +801,29 @@ async function dispatchRequestInternal<Op extends WalletApiOperation>(
       });
       return {};
     }
+    case WalletApiOperation.TestingGetDenomStats: {
+      const req = codecForTestingGetDenomStatsRequest().decode(payload);
+      const denomStats: TestingGetDenomStatsResponse = {
+        numKnown: 0,
+        numLost: 0,
+        numOffered: 0,
+      };
+      await wex.db.runReadOnlyTx(["denominations"], async (tx) => {
+        const denoms = await tx.denominations.indexes.byExchangeBaseUrl.getAll(
+          req.exchangeBaseUrl,
+        );
+        for (const d of denoms) {
+          denomStats.numKnown++;
+          if (d.isOffered) {
+            denomStats.numOffered++;
+          }
+          if (d.isLost) {
+            denomStats.numLost++;
+          }
+        }
+      });
+      return denomStats;
+    }
     case WalletApiOperation.ListExchanges: {
       return await listExchanges(wex);
     }