用Abp实现双因素认证（Two-Factor Authentication， 2FA）登录（一）：认证模块

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目录

• 原理
• 用户验证码校验模块
• 双因素认证模块
• 改写登录

在之前的博文 用Abp实现短信验证码免密登录（一）：短信校验模块 一文中，我们实现了用户验证码校验模块，今天来拓展这个模块，使Abp用户系统支持双因素认证（Two-Factor Authentication）功能。

双因素认证（Two-Factor Authentication，简称 2FA）是使用两个或多个因素的任意组合来验证用户身份，例如用户提供密码后，还要提供短消息发送的验证码，以证明用户确实拥有该手机。

国内大多数网站在登录屏正常登录后，检查是否有必要进行二次验证，如果有必要则进入二阶段验证屏，如下图：

接下来就来实践这个小项目

本示例基于之前的博文内容，你需要登录并绑定正确的手机号，才能使用双因素认证。示例代码已经放在了GitHub上：Github:matoapp-samples

原理

查看Abp源码，Abp帮我们定义了几个Setting，用于配置双因素认证的相关功能。确保在数据库中将Abp.Zero.UserManagement.TwoFactorLogin.IsEnabled打开。

public static class TwoFactorLogin
{
    /// <summary>
    /// "Abp.Zero.UserManagement.TwoFactorLogin.IsEnabled".
    /// </summary>
    public const string IsEnabled = "Abp.Zero.UserManagement.TwoFactorLogin.IsEnabled";

    /// <summary>
    /// "Abp.Zero.UserManagement.TwoFactorLogin.IsEmailProviderEnabled".
    /// </summary>
    public const string IsEmailProviderEnabled = "Abp.Zero.UserManagement.TwoFactorLogin.IsEmailProviderEnabled";

    /// <summary>
    /// "Abp.Zero.UserManagement.TwoFactorLogin.IsSmsProviderEnabled".
    /// </summary>
    public const string IsSmsProviderEnabled = "Abp.Zero.UserManagement.TwoFactorLogin.IsSmsProviderEnabled";

...
}

在AbpUserManager的GetValidTwoFactorProvidersAsync方法中

Abp.Zero.UserManagement.TwoFactorLogin.IsSmsProviderEnabled开启后将添加“Phone”到Provider中，将启用短信验证方式。

Abp.Zero.UserManagement.TwoFactorLogin.IsEmailProviderEnabled开启后将添加“Email”到Provider中，将启用邮箱验证方式。

var isEmailProviderEnabled = await IsTrueAsync(
    AbpZeroSettingNames.UserManagement.TwoFactorLogin.IsEmailProviderEnabled,
    user.TenantId
);

if (provider == "Email" && !isEmailProviderEnabled)
{
    continue;
}

var isSmsProviderEnabled = await IsTrueAsync(
    AbpZeroSettingNames.UserManagement.TwoFactorLogin.IsSmsProviderEnabled,
    user.TenantId
);

if (provider == "Phone" && !isSmsProviderEnabled)
{
    continue;
}

在迁移中添加双因素认证的配置项

//双因素认证
AddSettingIfNotExists(AbpZeroSettingNames.UserManagement.TwoFactorLogin.IsEnabled, "true", tenantId);
AddSettingIfNotExists(AbpZeroSettingNames.UserManagement.TwoFactorLogin.IsSmsProviderEnabled, "true", tenantId);
AddSettingIfNotExists(AbpZeroSettingNames.UserManagement.TwoFactorLogin.IsEmailProviderEnabled, "true", tenantId);

将默认User的IsTwoFactorEnabled字段设为true

public User()
{
    this.IsTwoFactorEnabled= true;
}

用户验证码校验模块

使用AbpBoilerplate.Sms作为短信服务库。

之前定义了DomainService接口，已经实现了验证码的发送、验证码校验、解绑手机号、绑定手机号

这4个功能，通过定义用途（purpose）字段以校验区分短信模板

public interface ICaptchaManager
{
    Task BindAsync(string token);
    Task UnbindAsync(string token);
    Task SendCaptchaAsync(long userId, string phoneNumber, string purpose);
    Task<bool> VerifyCaptchaAsync(string token, string purpose = "IDENTITY_VERIFICATION");
}

添加一个用于双因素认证的purpose，在CaptchaPurpose枚举类型中添加TWO_FACTOR_AUTHORIZATION

public const string TWO_FACTOR_AUTHORIZATION = "TWO_FACTOR_AUTHORIZATION";

在SMS服务商管理端后台申请一个短信模板，用于双因素认证。

打开短信验证码的领域服务类SmsCaptchaManager， 添加TWO_FACTOR_AUTHORIZATION对应短信模板的编号

public async Task SendCaptchaAsync(long userId, string phoneNumber, string purpose)
{
    var captcha = CommonHelper.GetRandomCaptchaNumber();
    var model = new SendSmsRequest();
    model.PhoneNumbers = new string[] { phoneNumber };
    model.SignName = "MatoApp";
    model.TemplateCode = purpose switch
    {
        CaptchaPurpose.BIND_PHONENUMBER => "SMS_255330989",
        CaptchaPurpose.UNBIND_PHONENUMBER => "SMS_255330923",
        CaptchaPurpose.LOGIN => "SMS_255330901",
        CaptchaPurpose.IDENTITY_VERIFICATION => "SMS_255330974"
        CaptchaPurpose.TWO_FACTOR_AUTHORIZATION => "SMS_1587660"    //添加双因素认证对应短信模板的编号
    };

    ...
}

双因素认证模块

创建双因素认证领域服务类TwoFactorAuthorizationManager。

创建方法IsTwoFactorAuthRequiredAsync，返回登录用户是否需要双因素认证，若未开启TwoFactorLogin.IsEnabled、用户未开启双因素认证，或没有添加验证提供者，则跳过双因素认证。

public async Task<bool> IsTwoFactorAuthRequiredAsync(AbpLoginResult<Tenant, User> loginResult)
{
    if (!await settingManager.GetSettingValueAsync<bool>(AbpZeroSettingNames.UserManagement.TwoFactorLogin.IsEnabled))
    {
        return false;
    }

    if (!loginResult.User.IsTwoFactorEnabled)
    {
        return false;
    }
    if ((await _userManager.GetValidTwoFactorProvidersAsync(loginResult.User)).Count <= 0)
    {
        return false;
    }
    return true;
}

创建TwoFactorAuthenticateAsync，此方法根据回传的provider和token值校验用户是否通过双因素认证。

public async Task TwoFactorAuthenticateAsync(User user, string token, string provider)
{
    if (provider == "Email")
    {
        var isValidate = await emailCaptchaManager.VerifyCaptchaAsync(token, CaptchaPurpose.TWO_FACTOR_AUTHORIZATION);
        if (!isValidate)
        {
            throw new UserFriendlyException("验证码错误");
        }
    }

    else if (provider == "Phone")
    {
        var isValidate = await smsCaptchaManager.VerifyCaptchaAsync(token, CaptchaPurpose.TWO_FACTOR_AUTHORIZATION);
        if (!isValidate)
        {
            throw new UserFriendlyException("验证码错误");
        }
    }
    else
    {
        throw new UserFriendlyException("验证码提供者错误");
    }

}

创建SendCaptchaAsync，此方用于发送验证码。

public async Task SendCaptchaAsync(long userId, string Provider)
{
    var user = await _userManager.FindByIdAsync(userId.ToString());
    if (user == null)
    {
        throw new UserFriendlyException("找不到用户");

    }

    if (Provider == "Email")
    {
        if (!user.IsEmailConfirmed)
        {
            throw new UserFriendlyException("未绑定邮箱");
        }
        await emailCaptchaManager.SendCaptchaAsync(user.Id, user.EmailAddress, CaptchaPurpose.TWO_FACTOR_AUTHORIZATION);
    }
    else if (Provider == "Phone")
    {
        if (!user.IsPhoneNumberConfirmed)
        {
            throw new UserFriendlyException("未绑定手机号");
        }
        await smsCaptchaManager.SendCaptchaAsync(user.Id, user.PhoneNumber, CaptchaPurpose.TWO_FACTOR_AUTHORIZATION);
    }
    else
    {
        throw new UserFriendlyException("验证提供者错误");
    }
}

改写登录

接下来将双因素认证逻辑添加到登录流程中。

在web.core项目中，

添加类SendTwoFactorAuthenticateCaptchaModel，发送验证码时将一阶段返回的userId和选择验证方式的provider传入

public class SendTwoFactorAuthenticateCaptchaModel
{
    [Range(1, long.MaxValue)]
    public long UserId { get; set; }

    [Required]
    public string Provider { get; set; }
}

将验证码Token，和验证码提供者Provider的定义添加到AuthenticateModel中

public string TwoFactorAuthenticationToken { get; set; }

public string TwoFactorAuthenticationProvider { get; set; }

将提供者列表TwoFactorAuthenticationProviders，和是否需要双因素认证RequiresTwoFactorAuthenticate的定义添加到AuthenticateResultModel中

public bool RequiresTwoFactorAuthenticate { get; set; }

public IList<string> TwoFactorAuthenticationProviders { get; set; }

打开TokenAuthController，注入UserManager和TwoFactorAuthorizationManager服务对象

添加终节点SendTwoFactorAuthenticateCaptcha，用于前端调用发送验证码

[HttpPost]
public async Task SendTwoFactorAuthenticateCaptcha([FromBody] SendTwoFactorAuthenticateCaptchaModel model)
{
    await twoFactorAuthorizationManager.SendCaptchaAsync(model.UserId, model.Provider);
}

改写Authenticate方法如下：

[HttpPost]
public async Task<AuthenticateResultModel> Authenticate([FromBody] AuthenticateModel model)
{
    //用户名密码校验
    var loginResult = await GetLoginResultAsync(
        model.UserNameOrEmailAddress,
        model.Password,
        GetTenancyNameOrNull()
    );

    await userManager.InitializeOptionsAsync(loginResult.Tenant?.Id);

    //判断是否需要双因素认证
    if (await twoFactorAuthorizationManager.IsTwoFactorAuthRequiredAsync(loginResult))
    {
        //判断是否一阶段
        if (string.IsNullOrEmpty(model.TwoFactorAuthenticationToken))
        {
            //一阶登录完成，返回结果，等待二阶段登录
            return new AuthenticateResultModel
            {
                RequiresTwoFactorAuthenticate = true,
                UserId = loginResult.User.Id,
                TwoFactorAuthenticationProviders = await userManager.GetValidTwoFactorProvidersAsync(loginResult.User),

            };
        }
        //二阶段，双因素认证校验
        else
        {
            await twoFactorAuthorizationManager.TwoFactorAuthenticateAsync(loginResult.User, model.TwoFactorAuthenticationToken, model.TwoFactorAuthenticationProvider);
        }
    }

    //二阶段完成，返回最终登录结果
    var accessToken = CreateAccessToken(CreateJwtClaims(loginResult.Identity));
    return new AuthenticateResultModel
    {
        AccessToken = accessToken,
        EncryptedAccessToken = GetEncryptedAccessToken(accessToken),
        ExpireInSeconds = (int)_configuration.Expiration.TotalSeconds,
        UserId = loginResult.User.Id,
    };
}

至此，双因素认证的后端逻辑已经完成，接下来我们将补充“记住”功能，实现一段时间内免验证。