feat(2FA): [PM-17129] Login with 2FA Recovery Code

* feat(2FA): [PM-17129] Login with 2FA Recovery Code - Login with Recovery Code working.

* feat(2FA): [PM-17129] Login with 2FA Recovery Code - Feature flagged implementation.

* style(2FA): [PM-17129] Login with 2FA Recovery Code - Code cleanup.

* test(2FA): [PM-17129] Login with 2FA Recovery Code - Tests.

src/Core/Auth/Enums/TwoFactorProviderType.cs

@@ -10,4 +10,5 @@ public enum TwoFactorProviderType : byte
     Remember = 5,
     OrganizationDuo = 6,
     WebAuthn = 7,
+    RecoveryCode = 8,
 }

src/Core/Constants.cs

@@ -170,6 +170,7 @@ public static class FeatureFlagKeys
     public const string EnablePMAuthenticatorSync = "enable-pm-bwa-sync";
     public const string P15179_AddExistingOrgsFromProviderPortal = "pm-15179-add-existing-orgs-from-provider-portal";
     public const string AndroidMutualTls = "mutual-tls";
+    public const string RecoveryCodeLogin = "pm-17128-recovery-code-login";
     public const string PM3503_MobileAnonAddySelfHostAlias = "anon-addy-self-host-alias";
 
     public static List<string> GetAllKeys()

src/Core/Services/IUserService.cs

@@ -22,7 +22,6 @@ public interface IUserService
     Task<IdentityResult> CreateUserAsync(User user, string masterPasswordHash);
     Task SendMasterPasswordHintAsync(string email);
     Task SendTwoFactorEmailAsync(User user);
-    Task<bool> VerifyTwoFactorEmailAsync(User user, string token);
     Task<CredentialCreateOptions> StartWebAuthnRegistrationAsync(User user);
     Task<bool> DeleteWebAuthnKeyAsync(User user, int id);
     Task<bool> CompleteWebAuthRegistrationAsync(User user, int value, string name, AuthenticatorAttestationRawResponse attestationResponse);
@@ -41,8 +40,6 @@ public interface IUserService
     Task<IdentityResult> RefreshSecurityStampAsync(User user, string masterPasswordHash);
     Task UpdateTwoFactorProviderAsync(User user, TwoFactorProviderType type, bool setEnabled = true, bool logEvent = true);
     Task DisableTwoFactorProviderAsync(User user, TwoFactorProviderType type);
-    Task<bool> RecoverTwoFactorAsync(string email, string masterPassword, string recoveryCode);
-    Task<string> GenerateUserTokenAsync(User user, string tokenProvider, string purpose);
     Task<IdentityResult> DeleteAsync(User user);
     Task<IdentityResult> DeleteAsync(User user, string token);
     Task SendDeleteConfirmationAsync(string email);
@@ -55,9 +52,7 @@ public interface IUserService
     Task CancelPremiumAsync(User user, bool? endOfPeriod = null);
     Task ReinstatePremiumAsync(User user);
     Task EnablePremiumAsync(Guid userId, DateTime? expirationDate);
-    Task EnablePremiumAsync(User user, DateTime? expirationDate);
     Task DisablePremiumAsync(Guid userId, DateTime? expirationDate);
-    Task DisablePremiumAsync(User user, DateTime? expirationDate);
     Task UpdatePremiumExpirationAsync(Guid userId, DateTime? expirationDate);
     Task<UserLicense> GenerateLicenseAsync(User user, SubscriptionInfo subscriptionInfo = null,
         int? version = null);
@@ -91,9 +86,26 @@ public interface IUserService
 
     void SetTwoFactorProvider(User user, TwoFactorProviderType type, bool setEnabled = true);
 
+    [Obsolete("To be removed when the feature flag pm-17128-recovery-code-login is removed PM-18175.")]
+    Task<bool> RecoverTwoFactorAsync(string email, string masterPassword, string recoveryCode);
+
     /// <summary>
-    /// Returns true if the user is a legacy user. Legacy users use their master key as their encryption key.
-    /// We force these users to the web to migrate their encryption scheme.
+    /// This method is used by the TwoFactorAuthenticationValidator to recover two
+    /// factor for a user. This allows users to be logged in after a successful recovery
+    /// attempt.
+    ///
+    /// This method logs the event, sends an email to the user, and removes two factor
+    /// providers on the user account. This means that a user will have to accomplish
+    /// new device verification on their account on new logins, if it is enabled for their user.
+    /// </summary>
+    /// <param name="recoveryCode">recovery code associated with the user logging in</param>
+    /// <param name="user">The user to refresh the 2FA and Recovery Code on.</param>
+    /// <returns>true if the recovery code is valid; false otherwise</returns>
+    Task<bool> RecoverTwoFactorAsync(User user, string recoveryCode);
+
+    /// <summary>
+    /// Returns true if the user is a legacy user. Legacy users use their master key as their
+    /// encryption key. We force these users to the web to migrate their encryption scheme.
     /// </summary>
     Task<bool> IsLegacyUser(string userId);
 
@@ -101,7 +113,8 @@ public interface IUserService
     /// Indicates if the user is managed by any organization.
     /// </summary>
     /// <remarks>
-    /// A user is considered managed by an organization if their email domain matches one of the verified domains of that organization, and the user is a member of it.
+    /// A user is considered managed by an organization if their email domain matches one of the
+    /// verified domains of that organization, and the user is a member of it.
     /// The organization must be enabled and able to have verified domains.
     /// </remarks>
     /// <returns>

src/Core/Services/Implementations/UserService.cs

@@ -315,7 +315,7 @@ public class UserService : UserManager<User>, IUserService, IDisposable
             return;
         }
 
-        var token = await base.GenerateUserTokenAsync(user, TokenOptions.DefaultProvider, "DeleteAccount");
+        var token = await GenerateUserTokenAsync(user, TokenOptions.DefaultProvider, "DeleteAccount");
         await _mailService.SendVerifyDeleteEmailAsync(user.Email, user.Id, token);
     }
 
@@ -868,6 +868,10 @@ public class UserService : UserManager<User>, IUserService, IDisposable
         }
     }
 
+    /// <summary>
+    /// To be removed when the feature flag pm-17128-recovery-code-login is removed PM-18175.
+    /// </summary>
+    [Obsolete("Two Factor recovery is handled in the TwoFactorAuthenticationValidator.")]
     public async Task<bool> RecoverTwoFactorAsync(string email, string secret, string recoveryCode)
     {
         var user = await _userRepository.GetByEmailAsync(email);
@@ -897,6 +901,25 @@ public class UserService : UserManager<User>, IUserService, IDisposable
         return true;
     }
 
+    public async Task<bool> RecoverTwoFactorAsync(User user, string recoveryCode)
+    {
+        if (!CoreHelpers.FixedTimeEquals(
+                user.TwoFactorRecoveryCode,
+                recoveryCode.Replace(" ", string.Empty).Trim().ToLower()))
+        {
+            return false;
+        }
+
+        user.TwoFactorProviders = null;
+        user.TwoFactorRecoveryCode = CoreHelpers.SecureRandomString(32, upper: false, special: false);
+        await SaveUserAsync(user);
+        await _mailService.SendRecoverTwoFactorEmail(user.Email, DateTime.UtcNow, _currentContext.IpAddress);
+        await _eventService.LogUserEventAsync(user.Id, EventType.User_Recovered2fa);
+        await CheckPoliciesOnTwoFactorRemovalAsync(user);
+
+        return true;
+    }
+
     public async Task<Tuple<bool, string>> SignUpPremiumAsync(User user, string paymentToken,
         PaymentMethodType paymentMethodType, short additionalStorageGb, UserLicense license,
         TaxInfo taxInfo)
@@ -1081,7 +1104,7 @@ public class UserService : UserManager<User>, IUserService, IDisposable
         await EnablePremiumAsync(user, expirationDate);
     }
 
-    public async Task EnablePremiumAsync(User user, DateTime? expirationDate)
+    private async Task EnablePremiumAsync(User user, DateTime? expirationDate)
     {
         if (user != null && !user.Premium && user.Gateway.HasValue)
         {
@@ -1098,7 +1121,7 @@ public class UserService : UserManager<User>, IUserService, IDisposable
         await DisablePremiumAsync(user, expirationDate);
     }
 
-    public async Task DisablePremiumAsync(User user, DateTime? expirationDate)
+    private async Task DisablePremiumAsync(User user, DateTime? expirationDate)
     {
         if (user != null && user.Premium)
         {