fix(security): prevent TOTP reuse (#12616)

# Which Problems Are Solved TOTP codes could be reused, violating [RFC 6238, section 5.2](https://datatracker.ietf.org/doc/html/rfc6238#section-5.2). # How the Problems Are Solved Transmitted codes are now recorded in each success event. As the codes amount to secrets, they are not stored verbatim but as a randomly salted HMAC-SHA256 (`crypto.HMACValue`). Each value gets a fresh random salt, so an equal code always produces a different stored value and two entries can never be recognized as being derived from the same code. This is deliberately not a replacement for proper secret storage: with the salt stored alongside the hash and a 6 digit payload, anyone with event access can brute-force the code in milliseconds. That is acceptable here because a code is worthless once its window has passed. The `HMACValue` doc comment states the same. TOTP codes are low-entropy (6 digits), pseudo random codes. Therefore it is possible for the same code to be generated more than once over the lifetime of a user. In order to prevent the (unlikely) case where users login with large time intervalls and a generated code may be equal to the one last used a long time ago, we only check for codes used within the recent period window. A simpler implementation would be simply storing the latest consumed step, but the TOTP library does not return this value. Because of the allowed skew there are always 3 steps within the validation window, so we can't calculate the current step based on time alone. The retained history spans one period more than the validation window: validity is decided by the app server's clock, while the stored events carry the database clock, and the extra period absorbs the drift between them. **Note:** a reused code pushes a distinct `user.human.mfa.otp.check.reused` event, not a failed check event. A replay therefore stays observable through the Events API without counting towards the lockout policy. Otherwise anyone who captured a code could replay it to lock the user out. # Additional Changes - Read only the latest events in recheck query # Additional Context - Closes https://github.com/zitadel/zitadel/issues/6452 --------- Co-authored-by: Livio Spring <[email protected]> Co-authored-by: Copilot Autofix powered by AI <[email protected]> Co-authored-by: copilot-swe-agent[bot] <[email protected]> Co-authored-by: muhlemmer <[email protected]>
2026-11-03 12:52:16 +00:00 · 2026-08-27 07:17:39 +02:00
parent c9d747d407
commit 6128aeaa89
56 changed files with 850 additions and 8 deletions
@@ -500,6 +500,7 @@ Errors:
        AlreadyReady: المصادقة متعددة العوامل OTP (كلمة مرور لمرة واحدة) معدة بالفعل
        NotExisting: المصادقة متعددة العوامل OTP (كلمة مرور لمرة واحدة) غير موجودة
        InvalidCode: رمز غير صالح
+        Reused: تم استخدام هذا الرمز بالفعل. يرجى انتظار رمز جديد
        NotReady: المصادقة متعددة العوامل OTP (كلمة مرور لمرة واحدة) ليست جاهزة
    Locked: المستخدم مقفل
    SomethingWentWrong: حدث خطأ ما
@@ -492,6 +492,7 @@ Errors:
        AlreadyReady: Многофакторният OTP (OneTimePassword) вече е настроен
        NotExisting: Многофакторният OTP (OneTimePassword) не съществува
        InvalidCode: Невалиден код
+        Reused: Този код вече е използван. Моля, изчакайте нов код
        NotReady: Многофакторният OTP (OneTimePassword) не е готов
    Locked: Потребителят е заключен
    SomethingWentWrong: Нещо се обърка
@@ -504,6 +504,7 @@ Errors:
        AlreadyReady: Vícefaktorové OTP (jednorázové heslo) je již nastaveno
        NotExisting: Vícefaktorové OTP (jednorázové heslo) neexistuje
        InvalidCode: Neplatný kód
+        Reused: Tento kód již byl použit. Počkejte prosím na nový kód
        NotReady: Vícefaktorové OTP (jednorázové heslo) není připraveno
    Locked: Uživatel je uzamčen
    SomethingWentWrong: Něco se pokazilo
@@ -503,6 +503,7 @@ Errors:
        AlreadyReady: Multifaktor OTP (OneTimePassword) ist bereits eingerichtet
        NotExisting: Multifaktor OTP (OneTimePassword) existiert nicht
        InvalidCode: Code ist ungültig
+        Reused: Dieser Code wurde bereits verwendet. Bitte warten Sie auf einen neuen Code
        NotReady: Multifaktor OTP (OneTimePassword) ist nicht bereit
    Locked: Benutzer ist gesperrt
    SomethingWentWrong: Irgendetwas ist schief gelaufen
@@ -504,6 +504,7 @@ Errors:
        AlreadyReady: Multifactor OTP (OneTimePassword) is already setup
        NotExisting: Multifactor OTP (OneTimePassword) doesn't exist
        InvalidCode: Invalid code
+        Reused: This code was already used. Please wait for a new code
        NotReady: Multifactor OTP (OneTimePassword) isn't ready
    Locked: User is locked
    SomethingWentWrong: Something went wrong
@@ -487,6 +487,7 @@ Errors:
        AlreadyReady: El multifactor OTP (OneTimePassword) ya está configurado
        NotExisting: El multifactor OTP (OneTimePassword) no existe
        InvalidCode: Código no válido
+        Reused: Este código ya se ha utilizado. Espera a que se genere un nuevo código
        NotReady: El multifactor OTP (OneTimePassword) no está listo
    Locked: El usuario está bloqueado
    SomethingWentWrong: Algo fue mal
@@ -505,6 +505,7 @@ Errors:
        AlreadyReady: L'OTP multifactoriel (Mot de passe à usage unique) est déjà configuré.
        NotExisting: OTP multifactoriel (Mot de passe à usage unique) n'existe pas.
        InvalidCode: Code invalide
+        Reused: Ce code a déjà été utilisé. Veuillez attendre un nouveau code
        NotReady: Le système OTP multifactoriel (Mot de passe à usage unique) n'est pas prêt.
    Locked: L'utilisateur est verrouillé
    SomethingWentWrong: Il y a eu un problème
@@ -464,6 +464,7 @@ Errors:
        AlreadyReady: A többfaktoros OTP (OneTimePassword) már be van állítva
        NotExisting: A többfaktoros OTP (OneTimePassword) nem létezik
        InvalidCode: Érvénytelen kód
+        Reused: Ezt a kódot már felhasználták. Kérjük, várjon egy új kódra
        NotReady: A többfaktoros OTP (OneTimePassword) nem áll készen
    Locked: A felhasználó zárolva van
    SomethingWentWrong: Valami elromlott
@@ -464,6 +464,7 @@ Errors:
        AlreadyReady: OTP multifaktor (OneTimePassword) sudah disiapkan
        NotExisting: OTP multifaktor (OneTimePassword) tidak ada
        InvalidCode: Kode tidak valid
+        Reused: Kode ini sudah digunakan. Silakan tunggu kode baru
        NotReady: OTP multifaktor (OneTimePassword) belum siap
    Locked: Pengguna terkunci
    SomethingWentWrong: Ada yang tidak beres
@@ -505,6 +505,7 @@ Errors:
        AlreadyReady: Multifactor OTP (OneTimePassword) è già impostato
        NotExisting: Multifactor OTP (OneTimePassword) non esiste
        InvalidCode: Codice non valido
+        Reused: Questo codice è già stato utilizzato. Attendere un nuovo codice
        NotReady: Multifattore OTP (OneTimePassword) non è pronto
    Locked: L'utente è bloccato
    SomethingWentWrong: Qualcosa è andato storto
@@ -505,6 +505,7 @@ Errors:
        AlreadyReady: 多要素OTP（ワンタイムパスワード）は設定済みです
        NotExisting: 多要素OTP（ワンタイムパスワード）が存在しません
        InvalidCode: 無効なコード
+        Reused: このコードはすでに使用されています。新しいコードをお待ちください
        NotReady: 多要素OTP（ワンタイムパスワード）は利用可能でありません
    Locked: ユーザーはロックされています
    SomethingWentWrong: エラーが発生しました
@@ -504,6 +504,7 @@ Errors:
        AlreadyReady: 다중 인증 OTP(일회용 비밀번호)가 이미 설정되었습니다
        NotExisting: 다중 인증 OTP(일회용 비밀번호)가 존재하지 않습니다
        InvalidCode: 잘못된 코드입니다
+        Reused: 이 코드는 이미 사용되었습니다. 새 코드를 기다려 주세요
        NotReady: 다중 인증 OTP(일회용 비밀번호)가 준비되지 않았습니다
    Locked: 사용자가 잠겼습니다
    SomethingWentWrong: 문제가 발생했습니다
@@ -505,6 +505,7 @@ Errors:
        AlreadyReady: Мултифактор OTP (Еднократна Лозинка) е веќе подесена
        NotExisting: Мултифактор OTP (Еднократна Лозинка) не постои
        InvalidCode: Невалиден код
+        Reused: Овој код е веќе искористен. Ве молиме почекајте нов код
        NotReady: Мултифактор OTP (Еднократна Лозинка) не е подготвена
    Locked: Корисникот е заклучен
    SomethingWentWrong: Се случи нешто неочекувано
@@ -504,6 +504,7 @@ Errors:
        AlreadyReady: Multifactor OTP (OneTimePassword) is al ingesteld
        NotExisting: Multifactor OTP (OneTimePassword) bestaat niet
        InvalidCode: Ongeldige code
+        Reused: Deze code is al gebruikt. Wacht op een nieuwe code
        NotReady: Multifactor OTP (OneTimePassword) is niet klaar
    Locked: Gebruiker is vergrendeld
    SomethingWentWrong: Er is iets misgegaan
@@ -505,6 +505,7 @@ Errors:
        AlreadyReady: Wieloskładnikowe OTP (jednorazowe hasło) jest już skonfigurowane
        NotExisting: Wieloskładnikowe OTP (jednorazowe hasło) nie istnieje
        InvalidCode: Nieprawidłowy kod
+        Reused: Ten kod został już użyty. Poczekaj na nowy kod
        NotReady: Wieloskładnikowe OTP (jednorazowe hasło) nie jest gotowe
    Locked: Użytkownik jest zablokowany
    SomethingWentWrong: Coś poszło nie tak
@@ -501,6 +501,7 @@ Errors:
        AlreadyReady: A autenticação de vários fatores por OTP (senha única) já está configurada
        NotExisting: A autenticação de vários fatores por OTP (senha única) não existe
        InvalidCode: Código inválido
+        Reused: Este código já foi utilizado. Aguarde um novo código
        NotReady: A autenticação de vários fatores por OTP (senha única) não está pronta
    Locked: O usuário está bloqueado
    SomethingWentWrong: Algo deu errado
@@ -504,6 +504,7 @@ Errors:
        AlreadyReady: MFA OTP (OneTimePassword) este deja configurat
        NotExisting: Multifactor OTP (OneTimePassword) nu există
        InvalidCode: Cod nevalid
+        Reused: Acest cod a fost deja utilizat. Vă rugăm să așteptați un cod nou
        NotReady: Multifactor OTP (OneTimePassword) nu este gata
    Locked: Utilizatorul este blocat
    SomethingWentWrong: Ceva nu a mers bine
@@ -505,6 +505,7 @@ Errors:
        AlreadyReady: OTP (OneTimePassword) уже настроен
        NotExisting: OTP (OneTimePassword) не существует
        InvalidCode: Неверный код
+        Reused: Этот код уже был использован. Пожалуйста, дождитесь нового кода
        NotReady: OTP (OneTimePassword) не готов
    Locked: Пользователь заблокирован
    SomethingWentWrong: Что-то пошло не так
@@ -504,6 +504,7 @@ Errors:
        AlreadyReady: Tvåfaktor OTP (OneTimePassword) är redan konfigurerat
        NotExisting: Tvåfaktor OTP (OneTimePassword) finns inte
        InvalidCode: Ogiltig kod
+        Reused: Den här koden har redan använts. Vänta på en ny kod
        NotReady: Tvåfaktor OTP (OneTimePassword) är inte redo
    Locked: Användaren är spärrad
    SomethingWentWrong: Någonting gick fel
@@ -504,6 +504,7 @@ Errors:
        AlreadyReady: Çok faktörlü OTP (Tek Seferlik Şifre) zaten ayarlanmış
        NotExisting: Çok faktörlü OTP (Tek Seferlik Şifre) mevcut değil
        InvalidCode: Geçersiz kod
+        Reused: Bu kod zaten kullanıldı. Lütfen yeni bir kod bekleyin
        NotReady: Çok faktörlü OTP (Tek Seferlik Şifre) hazır değil
    Locked: Kullanıcı kilitli
    SomethingWentWrong: Bir şeyler yanlış gitti
@@ -505,6 +505,7 @@ Errors:
        AlreadyReady: Багатофакторний OTP (одноразовий пароль) уже налаштовано
        NotExisting: Багатофакторний OTP (одноразовий пароль) не існує
        InvalidCode: Недійсний код
+        Reused: Цей код вже було використано. Будь ласка, зачекайте на новий код
        NotReady: Багатофакторний OTP (одноразовий пароль) не готовий
    Locked: Користувача заблоковано
    SomethingWentWrong: Щось пішло не так
@@ -504,6 +504,7 @@ Errors:
        AlreadyReady: OTP (一次性密码) 已设置
        NotExisting: OTP (一次性密码) 不存在
        InvalidCode: 无效的验证码
+        Reused: 此验证码已被使用。请等待新的验证码
        NotReady: OTP (一次性密码) 还没准备好
    Locked: 用户被锁定
    SomethingWentWrong: 似乎出问题了