From 4968ea0adb807bc800b8217469e45ed3cddee247 Mon Sep 17 00:00:00 2001
From: Bernd Schoolmann <mail@quexten.com>
Date: Mon, 17 Mar 2025 16:34:04 +0100
Subject: [PATCH] Add prelogin response

---
 src/Identity/Controllers/AccountsController.cs | 18 +++++++++++++++++-
 .../Response/Accounts/PreloginResponseModel.cs |  7 +++++--
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/src/Identity/Controllers/AccountsController.cs b/src/Identity/Controllers/AccountsController.cs
index c840a7ddc5..3ffeeec2ca 100644
--- a/src/Identity/Controllers/AccountsController.cs
+++ b/src/Identity/Controllers/AccountsController.cs
@@ -1,10 +1,13 @@
 using System.Diagnostics;
 using System.Text;
+using System.Text.Json;
 using Bit.Core;
 using Bit.Core.Auth.Enums;
 using Bit.Core.Auth.Models.Api.Request.Accounts;
+using Bit.Core.Auth.Models.Api.Request.Opaque;
 using Bit.Core.Auth.Models.Api.Response.Accounts;
 using Bit.Core.Auth.Models.Business.Tokenables;
+using Bit.Core.Auth.Repositories;
 using Bit.Core.Auth.Services;
 using Bit.Core.Auth.UserFeatures.Registration;
 using Bit.Core.Auth.UserFeatures.WebAuthnLogin;
@@ -45,6 +48,7 @@ public class AccountsController : Controller
     private readonly IReferenceEventService _referenceEventService;
     private readonly IFeatureService _featureService;
     private readonly IDataProtectorTokenFactory<RegistrationEmailVerificationTokenable> _registrationEmailVerificationTokenDataFactory;
+    private readonly IOpaqueKeyExchangeCredentialRepository _opaqueKeyExchangeCredentialRepository;
 
     private readonly byte[] _defaultKdfHmacKey = null;
     private static readonly List<UserKdfInformation> _defaultKdfResults =
@@ -93,6 +97,7 @@ public class AccountsController : Controller
         IReferenceEventService referenceEventService,
         IFeatureService featureService,
         IDataProtectorTokenFactory<RegistrationEmailVerificationTokenable> registrationEmailVerificationTokenDataFactory,
+        IOpaqueKeyExchangeCredentialRepository opaqueKeyExchangeCredentialRepository,
         GlobalSettings globalSettings
         )
     {
@@ -107,6 +112,7 @@ public class AccountsController : Controller
         _referenceEventService = referenceEventService;
         _featureService = featureService;
         _registrationEmailVerificationTokenDataFactory = registrationEmailVerificationTokenDataFactory;
+        _opaqueKeyExchangeCredentialRepository = opaqueKeyExchangeCredentialRepository;
 
         if (CoreHelpers.SettingHasValue(globalSettings.KdfDefaultHashKey))
         {
@@ -259,7 +265,17 @@ public class AccountsController : Controller
         {
             kdfInformation = GetDefaultKdf(model.Email);
         }
-        return new PreloginResponseModel(kdfInformation);
+
+        var user = await _userRepository.GetByEmailAsync(model.Email);
+        var credential = await _opaqueKeyExchangeCredentialRepository.GetByUserIdAsync(user.Id);
+        if (credential != null)
+        {
+            return new PreloginResponseModel(kdfInformation, JsonSerializer.Deserialize<CipherConfiguration>(credential.CipherConfiguration)!);
+        }
+        else
+        {
+            return new PreloginResponseModel(kdfInformation, null);
+        }
     }
 
     [HttpGet("webauthn/assertion-options")]
diff --git a/src/Identity/Models/Response/Accounts/PreloginResponseModel.cs b/src/Identity/Models/Response/Accounts/PreloginResponseModel.cs
index 129aa3e7a9..46c988edd6 100644
--- a/src/Identity/Models/Response/Accounts/PreloginResponseModel.cs
+++ b/src/Identity/Models/Response/Accounts/PreloginResponseModel.cs
@@ -1,20 +1,23 @@
-using Bit.Core.Enums;
+using Bit.Core.Auth.Models.Api.Request.Opaque;
+using Bit.Core.Enums;
 using Bit.Core.Models.Data;
 
 namespace Bit.Identity.Models.Response.Accounts;
 
 public class PreloginResponseModel
 {
-    public PreloginResponseModel(UserKdfInformation kdfInformation)
+    public PreloginResponseModel(UserKdfInformation kdfInformation, CipherConfiguration opaqueConfiguration)
     {
         Kdf = kdfInformation.Kdf;
         KdfIterations = kdfInformation.KdfIterations;
         KdfMemory = kdfInformation.KdfMemory;
         KdfParallelism = kdfInformation.KdfParallelism;
+        OpaqueConfiguration = opaqueConfiguration;
     }
 
     public KdfType Kdf { get; set; }
     public int KdfIterations { get; set; }
     public int? KdfMemory { get; set; }
     public int? KdfParallelism { get; set; }
+    public CipherConfiguration OpaqueConfiguration { get; set; }
 }