Require 2FA token in order to disiable 2FA. Added 2FA recovery code to data/domain model and exposed recover and regenerate 2FA APIs

src/Api/Controllers/AccountsController.cs

@@ -194,7 +194,7 @@ namespace Bit.Api.Controllers
                 throw new BadRequestException("MasterPasswordHash", "Invalid password.");
             }
 
-            if(model.Enabled.Value && !await _userManager.VerifyTwoFactorTokenAsync(user, "Authenticator", model.Token))
+            if(!await _userManager.VerifyTwoFactorTokenAsync(user, "Authenticator", model.Token))
             {
                 await Task.Delay(2000);
                 throw new BadRequestException("Token", "Invalid token.");
@@ -202,12 +202,66 @@ namespace Bit.Api.Controllers
 
             user.TwoFactorProvider = TwoFactorProvider.Authenticator;
             user.TwoFactorEnabled = model.Enabled.Value;
+            user.TwoFactorRecoveryCode = user.TwoFactorEnabled ? Guid.NewGuid().ToString("N") : null;
             await _userService.SaveUserAsync(user);
 
             var response = new TwoFactorResponseModel(user);
             return response;
         }
 
+        [HttpPut("two-factor-recover")]
+        [HttpPost("two-factor-recover")]
+        public async Task<TwoFactorResponseModel> PutTwoFactorRecover([FromBody]RecoverTwoFactorRequestModel model)
+        {
+            var user = _currentContext.User;
+            if(!await _userManager.CheckPasswordAsync(user, model.MasterPasswordHash))
+            {
+                await Task.Delay(2000);
+                throw new BadRequestException("MasterPasswordHash", "Invalid password.");
+            }
+
+            if(string.Compare(user.TwoFactorRecoveryCode, model.RecoveryCode, true) != 0)
+            {
+                await Task.Delay(2000);
+                throw new BadRequestException("RecoveryCode", "Invalid recovery code.");
+            }
+
+            user.TwoFactorProvider = TwoFactorProvider.Authenticator;
+            user.TwoFactorEnabled = false;
+            user.TwoFactorRecoveryCode = null;
+            await _userService.SaveUserAsync(user);
+
+            var response = new TwoFactorResponseModel(user);
+            return response;
+        }
+
+        [HttpPut("two-factor-regenerate")]
+        [HttpPost("two-factor-regenerate")]
+        public async Task<TwoFactorResponseModel> PutTwoFactorRegenerate([FromBody]RegenerateTwoFactorRequestModel model)
+        {
+            var user = _currentContext.User;
+            if(!await _userManager.CheckPasswordAsync(user, model.MasterPasswordHash))
+            {
+                await Task.Delay(2000);
+                throw new BadRequestException("MasterPasswordHash", "Invalid password.");
+            }
+
+            if(!await _userManager.VerifyTwoFactorTokenAsync(user, "Authenticator", model.Token))
+            {
+                await Task.Delay(2000);
+                throw new BadRequestException("Token", "Invalid token.");
+            }
+
+            if(user.TwoFactorEnabled)
+            {
+                user.TwoFactorRecoveryCode = Guid.NewGuid().ToString("N");
+                await _userService.SaveUserAsync(user);
+            }
+
+            var response = new TwoFactorResponseModel(user);
+            return response;
+        }
+
         [HttpPost("delete")]
         public async Task PostDelete([FromBody]DeleteAccountRequestModel model)
         {

src/Api/Models/Request/Accounts/RecoverTwoFactorRequestModel.cs

@@ -0,0 +1,14 @@
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+
+namespace Bit.Api.Models
+{
+    public class RecoverTwoFactorRequestModel
+    {
+        [Required]
+        public string MasterPasswordHash { get; set; }
+        [Required]
+        [StringLength(32)]
+        public string RecoveryCode { get; set; }
+    }
+}

src/Api/Models/Request/Accounts/RegenerateTwoFactorRequestModel.cs

@@ -0,0 +1,14 @@
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+
+namespace Bit.Api.Models
+{
+    public class RegenerateTwoFactorRequestModel
+    {
+        [Required]
+        public string MasterPasswordHash { get; set; }
+        [Required]
+        [StringLength(50)]
+        public string Token { get; set; }
+    }
+}

src/Api/Models/Request/Accounts/UpdateTwoFactorRequestModel.cs

@@ -3,21 +3,14 @@ using System.ComponentModel.DataAnnotations;
 
 namespace Bit.Api.Models
 {
-    public class UpdateTwoFactorRequestModel : IValidatableObject
+    public class UpdateTwoFactorRequestModel
     {
         [Required]
         public string MasterPasswordHash { get; set; }
         [Required]
         public bool? Enabled { get; set; }
+        [Required]
         [StringLength(50)]
         public string Token { get; set; }
-
-        public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
-        {
-            if(Enabled.HasValue && Enabled.Value && string.IsNullOrWhiteSpace(Token))
-            {
-                yield return new ValidationResult("Token is required.", new[] { "Token" });
-            }
-        }
     }
 }

src/Api/Models/Response/TwoFactorResponseModel.cs

@@ -17,10 +17,12 @@ namespace Bit.Api.Models
             TwoFactorEnabled = user.TwoFactorEnabled;
             AuthenticatorKey = user.AuthenticatorKey;
             TwoFactorProvider = user.TwoFactorProvider;
+            TwoFactorRecoveryCode = user.TwoFactorRecoveryCode;
         }
 
         public bool TwoFactorEnabled { get; set; }
         public TwoFactorProvider? TwoFactorProvider { get; set; }
         public string AuthenticatorKey { get; set; }
+        public string TwoFactorRecoveryCode { get; set; }
     }
 }

src/Core/Domains/User.cs

@@ -17,6 +17,7 @@ namespace Bit.Core.Domains
         public bool TwoFactorEnabled { get; set; }
         public TwoFactorProvider? TwoFactorProvider { get; set; }
         public string AuthenticatorKey { get; set; }
+        public string TwoFactorRecoveryCode { get; set; }
         public DateTime CreationDate { get; internal set; } = DateTime.UtcNow;
         public DateTime RevisionDate { get; internal set; } = DateTime.UtcNow;
 

src/Sql/dbo/Stored Procedures/User_Update.sql

@@ -10,6 +10,7 @@
     @TwoFactorEnabled BIT,
     @TwoFactorProvider TINYINT,
     @AuthenticatorKey NVARCHAR(50),
+    @TwoFactorRecoveryCode NVARCHAR(32),
     @CreationDate DATETIME2(7),
     @RevisionDate DATETIME2(7)
 AS
@@ -29,6 +30,7 @@ BEGIN
         [TwoFactorEnabled] = @TwoFactorEnabled,
         [TwoFactorProvider] = @TwoFactorProvider,
         [AuthenticatorKey] = @AuthenticatorKey,
+        [TwoFactorRecoveryCode] = @TwoFactorRecoveryCode,
         [CreationDate] = @CreationDate,
         [RevisionDate] = @RevisionDate
     WHERE

src/Sql/dbo/Tables/User.sql

@@ -10,6 +10,7 @@
     [TwoFactorEnabled]      BIT              NOT NULL,
     [TwoFactorProvider]     TINYINT          NULL,
     [AuthenticatorKey]      NVARCHAR (50)    NULL,
+    [TwoFactorRecoveryCode] NVARCHAR (32)    NULL,
     [CreationDate]          DATETIME2 (7)    NOT NULL,
     [RevisionDate]          DATETIME2 (7)    NOT NULL,
     CONSTRAINT [PK_User] PRIMARY KEY CLUSTERED ([Id] ASC)