Small code quality improvements

- Fix misleading JSDoc comment in cache.ts
- Mitigate timing-based username enumeration in Basic auth
- Extract duplicated TOTP configuration into private method
- Replace manual peer counter with clients.length in Prometheus metrics
- Simplify isValidPasswordHash return expression

src/server/database/repositories/user/service.ts

@@ -58,6 +58,17 @@ export class UserService {
     this.#statements = createPreparedStatement(db);
   }
 
+  #createTotp(user: Pick<UserType, 'username' | 'totpKey'>) {
+    return new TOTP({
+      issuer: 'wg-easy',
+      label: user.username,
+      algorithm: 'SHA1',
+      digits: 6,
+      period: 30,
+      secret: user.totpKey!,
+    });
+  }
+
   async getAll() {
     return this.#statements.findAll.execute();
   }
@@ -160,18 +171,8 @@ export class UserService {
             return { success: false, error: 'UNEXPECTED_ERROR' };
           }
 
-          const totp = new TOTP({
-            issuer: 'wg-easy',
-            label: txUser.username,
-            algorithm: 'SHA1',
-            digits: 6,
-            period: 30,
-            secret: txUser.totpKey,
-          });
-
-          const valid = totp.validate({ token: code, window: 1 });
-
-          if (valid === null) {
+          const totp = this.#createTotp(txUser);
+          if (totp.validate({ token: code, window: 1 }) === null) {
             return { success: false, error: 'INVALID_TOTP_CODE' };
           }
         }
@@ -199,18 +200,8 @@ export class UserService {
         throw new Error('TOTP key is not set');
       }
 
-      const totp = new TOTP({
-        issuer: 'wg-easy',
-        label: txUser.username,
-        algorithm: 'SHA1',
-        digits: 6,
-        period: 30,
-        secret: txUser.totpKey,
-      });
-
-      const valid = totp.validate({ token: code, window: 1 });
-
-      if (valid === null) {
+      const totp = this.#createTotp(txUser);
+      if (totp.validate({ token: code, window: 1 }) === null) {
         throw new Error('Invalid TOTP code');
       }
 

src/server/routes/metrics/prometheus.get.ts

@@ -6,14 +6,12 @@ export default defineMetricsHandler('prometheus', async ({ event }) => {
 async function getPrometheusResponse() {
   const wgInterface = await Database.interfaces.get();
   const clients = await WireGuard.getAllClients();
-  let wireguardPeerCount = 0;
   let wireguardEnabledPeersCount = 0;
   let wireguardConnectedPeersCount = 0;
   const wireguardSentBytes = [];
   const wireguardReceivedBytes = [];
   const wireguardLatestHandshakeSeconds = [];
   for (const client of clients) {
-    wireguardPeerCount++;
     if (client.enabled === true) {
       wireguardEnabledPeersCount++;
     }
@@ -41,7 +39,7 @@ async function getPrometheusResponse() {
   const returnText = [
     '# HELP wireguard_configured_peers',
     '# TYPE wireguard_configured_peers gauge',
-    `wireguard_configured_peers{${id}} ${wireguardPeerCount}`,
+    `wireguard_configured_peers{${id}} ${clients.length}`,
     '',
     '# HELP wireguard_enabled_peers',
     '# TYPE wireguard_enabled_peers gauge',

src/server/utils/cache.ts

@@ -6,7 +6,7 @@ type Opts = {
 };
 
 /**
- * Cache function for 1 hour
+ * Cache the result of a function for the given expiry time
  */
 export function cacheFunction<T>(fn: () => T, { expiry }: Opts): () => T {
   let cache: { value: T; expiry: number } | null = null;

src/server/utils/password.ts

@@ -28,11 +28,7 @@ export function isValidPasswordHash(hash: string): boolean {
   try {
     const obj = deserialize(hash);
 
-    if (obj.id !== 'argon2i' && obj.id !== 'argon2d' && obj.id !== 'argon2id') {
-      return false;
-    }
-
-    return true;
+    return obj.id === 'argon2i' || obj.id === 'argon2d' || obj.id === 'argon2id';
   } catch {
     return false;
   }

src/server/utils/session.ts

@@ -70,26 +70,21 @@ export async function getCurrentUser(event: H3Event) {
       });
     }
 
-    // TODO: timing can be used to enumerate usernames
-
     const foundUser = await Database.users.getByUsername(username);
 
-    if (!foundUser) {
-      throw createError({
-        statusCode: 401,
-        statusMessage: 'Session failed',
-      });
-    }
-
-    const userHashPassword = foundUser.password;
+    // Always verify password to prevent timing-based username enumeration
+    const userHashPassword =
+      foundUser?.password ??
+      '$argon2id$v=19$m=65536,t=3,p=4$aaaaaaaaaaaaaaaa$bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb';
     const passwordValid = await isPasswordValid(password, userHashPassword);
 
-    if (!passwordValid) {
+    if (!foundUser || !passwordValid) {
       throw createError({
         statusCode: 401,
         statusMessage: 'Session failed',
       });
     }
+
     user = foundUser;
   } else {
     throw createError({