server/src/Identity/Controllers/AccountsController.cs

using Bit.Core.Auth.Models.Api.Request.Accounts;
using Bit.Core.Auth.Models.Api.Response.Accounts;
using Bit.Core.Auth.Services;
using Bit.Core.Auth.Utilities;
using Bit.Core.Enums;
using Bit.Core.Exceptions;
using Bit.Core.Models.Data;
using Bit.Core.Repositories;
using Bit.Core.Services;
using Bit.SharedWeb.Utilities;
using Microsoft.AspNetCore.Mvc;

namespace Bit.Identity.Controllers;

[Route("accounts")]
[ExceptionHandlerFilter]
public class AccountsController : Controller
{
    private readonly ILogger<AccountsController> _logger;
    private readonly IUserRepository _userRepository;
    private readonly IUserService _userService;
    private readonly ICaptchaValidationService _captchaValidationService;

    public AccountsController(
        ILogger<AccountsController> logger,
        IUserRepository userRepository,
        IUserService userService,
        ICaptchaValidationService captchaValidationService)
    {
        _logger = logger;
        _userRepository = userRepository;
        _userService = userService;
        _captchaValidationService = captchaValidationService;
    }

    // Moved from API, If you modify this endpoint, please update API as well. Self hosted installs still use the API endpoints.
    [HttpPost("register")]
    [CaptchaProtected]
    public async Task<RegisterResponseModel> PostRegister([FromBody] RegisterRequestModel model)
    {
        var user = model.ToUser();
        var result = await _userService.RegisterUserAsync(user, model.MasterPasswordHash,
            model.Token, model.OrganizationUserId);
        if (result.Succeeded)
        {
            var captchaBypassToken = _captchaValidationService.GenerateCaptchaBypassToken(user);
            return new RegisterResponseModel(captchaBypassToken);
        }

        foreach (var error in result.Errors.Where(e => e.Code != "DuplicateUserName"))
        {
            ModelState.AddModelError(string.Empty, error.Description);
        }

        await Task.Delay(2000);
        throw new BadRequestException(ModelState);
    }

    // Moved from API, If you modify this endpoint, please update API as well. Self hosted installs still use the API endpoints.
    [HttpPost("prelogin")]
    public async Task<PreloginResponseModel> PostPrelogin([FromBody] PreloginRequestModel model)
    {
        var kdfInformation = await _userRepository.GetKdfInformationByEmailAsync(model.Email);
        if (kdfInformation == null)
        {
            kdfInformation = new UserKdfInformation
            {
                Kdf = KdfType.PBKDF2_SHA256,
                KdfIterations = 100000,
            };
        }
        return new PreloginResponseModel(kdfInformation);
    }
}