initial commit

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/utils/totp.ts

@@ -0,0 +1,20 @@
+import * as OTPAuthLib from 'otpauth';
+import { decrypt } from './encryption';
+
+export const OTPAuth = {
+  verify(encryptedSecret: string, code: string): boolean {
+    try {
+      const secret = decrypt(encryptedSecret);
+      const totp = new OTPAuthLib.TOTP({
+        secret: OTPAuthLib.Secret.fromBase32(secret),
+        algorithm: 'SHA1',
+        digits: 6,
+        period: 30,
+      });
+      const delta = totp.validate({ token: code, window: 1 });
+      return delta !== null;
+    } catch {
+      return false;
+    }
+  },
+};