用Abp实现两步验证（Two-Factor Authentication，2FA）登录（三）：免登录验证

免登录验证是用户在首次两步验证通过后，在常用的设备（浏览器）中，在一定时间内不需要再次输入验证码直接登录。

常见的网页上提示“7天免登录验证”或“信任此设备，7天内无需两步验证”等内容。
这样可以提高用户的体验。但同时也会带来一定的安全风险，因此需要用户自己决定是否开启。

原理

常用的实现方式是在用户登录成功后，生成一个随机的字符串Token，将此Token保存在用户浏览器的 cookie 中，同时将这个字符串保存在用户的数据库中。当用户再次访问时，如果 cookie 中的字符串和数据库中的字符串相同，则免登录验证通过。流程图如下：

为了安全，Token采用对称加密传输存储，同时参与校验的还有用户Id，以进一步验证数据一致性。Token存储于数据库中并设置过期时间(ExpireDate)
认证机制由JSON Web Token（JWT）实现，通过自定义Payload声明中添加Token和用户Id字段，实现校验。

下面来看代码实现：

修改请求报文

项目添加对Microsoft.AspNetCore.Authentication.JwtBearer包的引用

<PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="7.0.4" />

在Authenticate方法参数AuthenticateModel中添加RememberClient和RememberClientToken属性，

当首次登录时，若用户选择免登录，RememberClient为true，
非首次登录时，系统校验RememberClientToken合法性，是否允许跳过两步验证。

public class AuthenticateModel
{..public bool RememberClient { get; set; }public string RememberClientToken { get; set; }
}

同时返回值中添加RememberClientToken，用于首次登录生成的Token

public class AuthenticateResultModel
{...public string RememberClientToken { get; set; }
}

配置JwtBearerOptions

在TokenAuthController的Authenticate方法中，添加validation参数：

var validationParameters = new TokenValidationParameters
{ValidAudience = _configuration.Audience,ValidIssuer = _configuration.Issuer,IssuerSigningKey = _configuration.SecurityKey
};

在默认的AbpBoilerplate模板项目中已经为我们生成了默认配置

 "Authentication": {"JwtBearer": {"IsEnabled": "true","SecurityKey": "MatoAppSample_C421AAEE0D114E9C","Issuer": "MatoAppSample","Audience": "MatoAppSample"}},

生成Token

在TokenAuthController类中

添加自定义Payload声明类型

public const string USER_IDENTIFIER_CLAIM = "USER_IDENTIFIER_CLAIM";
public const string REMEMBER_CLIENT_TOKEN = "REMEMBER_CLIENT_TOKEN";

添加生成Token的方法CreateAccessToken，它将根据自定义Payload声明，validationParameters生成经过SHA256加密的Token，过期时间即有效期为7天：

private string CreateAccessToken(IEnumerable<Claim> claims, TokenValidationParameters validationParameters)
{var now = DateTime.UtcNow;var expiration = TimeSpan.FromDays(7);var signingCredentials = new SigningCredentials(validationParameters.IssuerSigningKey, SecurityAlgorithms.HmacSha256);var jwtSecurityToken = new JwtSecurityToken(issuer: validationParameters.ValidIssuer,audience: validationParameters.ValidAudience,claims: claims,notBefore: now,expires: now.Add(expiration),signingCredentials: signingCredentials);return new JwtSecurityTokenHandler().WriteToken(jwtSecurityToken);
}

更改方法TwoFactorAuthenticateAsync的签名，添加rememberClient和validationParameters形参

在该方法中添加生成Token的代码

if (rememberClient)
{if (await settingManager.GetSettingValueAsync<bool>(AbpZeroSettingNames.UserManagement.TwoFactorLogin.IsRememberBrowserEnabled)){var expiration = TimeSpan.FromDays(7);var tokenValidityKey = Guid.NewGuid().ToString("N");var accessToken = CreateAccessToken(new[]{new Claim(USER_IDENTIFIER_CLAIM, user.ToUserIdentifier().ToString()),new Claim(REMEMBER_CLIENT_TOKEN, tokenValidityKey)}, validationParameters);await _userManager.AddTokenValidityKeyAsync(user, tokenValidityKey,DateTime.Now.Add(expiration));return accessToken;}
}

校验Token

添加校验方法TwoFactorClientRememberedAsync，它表示校验结果是否允许跳过两步验证

public async Task<bool> TwoFactorClientRememberedAsync(UserIdentifier userIdentifier, string TwoFactorRememberClientToken, TokenValidationParameters validationParameters)
{if (!await settingManager.GetSettingValueAsync<bool>(AbpZeroSettingNames.UserManagement.TwoFactorLogin.IsRememberBrowserEnabled)){return false;}if (string.IsNullOrWhiteSpace(TwoFactorRememberClientToken)){return false;}try{var tokenHandler = new JwtSecurityTokenHandler();if (tokenHandler.CanReadToken(TwoFactorRememberClientToken)){try{SecurityToken validatedToken;var principal = tokenHandler.ValidateToken(TwoFactorRememberClientToken, validationParameters, out validatedToken);var userIdentifierString = principal.Claims.First(c => c.Type == TwoFactorAuthorizationManager.USER_IDENTIFIER_CLAIM);if (userIdentifierString == null){throw new SecurityTokenException(TwoFactorAuthorizationManager.USER_IDENTIFIER_CLAIM + " invalid");}var tokenValidityKeyInClaims = principal.Claims.First(c => c.Type == TwoFactorAuthorizationManager.REMEMBER_CLIENT_TOKEN);var currentUserIdentifier = UserIdentifier.Parse(userIdentifierString.Value);var user = _userManager.GetUserById(currentUserIdentifier.UserId);var isValidityKetValid = AsyncHelper.RunSync(() => _userManager.IsTokenValidityKeyValidAsync(user, tokenValidityKeyInClaims.Value));if (!isValidityKetValid){throw new SecurityTokenException(REMEMBER_CLIENT_TOKEN + " invalid");}return userIdentifierString.Value == userIdentifier.ToString();}catch (Exception ex){LogHelper.LogException(ex);}}}catch (Exception ex){LogHelper.LogException(ex);}return false;
}

更改方法IsTwoFactorAuthRequiredAsync添加twoFactorRememberClientToken和validationParameters形参

添加对TwoFactorClientRememberedAsync的调用

public async Task<bool> IsTwoFactorAuthRequiredAsync(AbpLoginResult<Tenant, User> loginResult, string TwoFactorRememberClientToken, TokenValidationParameters validationParameters)
{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;}if (await TwoFactorClientRememberedAsync(loginResult.User.ToUserIdentifier(), TwoFactorRememberClientToken, validationParameters)){return false;}return true;
}

修改认证EndPoint

在TokenAuthController的Authenticate方法中，找到校验代码片段，对以上两个方法的调用传入实参

...
await userManager.InitializeOptionsAsync(loginResult.Tenant?.Id);
string twoFactorRememberClientToken = null;
if (await twoFactorAuthorizationManager.IsTwoFactorAuthRequiredAsync(loginResult, model.RememberClientToken, validationParameters))
{if (string.IsNullOrEmpty(model.TwoFactorAuthenticationToken)){return new AuthenticateResultModel{RequiresTwoFactorAuthenticate = true,UserId = loginResult.User.Id,TwoFactorAuthenticationProviders = await userManager.GetValidTwoFactorProvidersAsync(loginResult.User),};}else{twoFactorRememberClientToken = await twoFactorAuthorizationManager.TwoFactorAuthenticateAsync(loginResult.User, model.TwoFactorAuthenticationToken, model.TwoFactorAuthenticationProvider, model.RememberClient, validationParameters);}
}

完整的TwoFactorAuthorizationManager代码如下：

public class TwoFactorAuthorizationManager : ITransientDependency
{public const string USER_IDENTIFIER_CLAIM = "USER_IDENTIFIER_CLAIM";public const string REMEMBER_CLIENT_TOKEN = "REMEMBER_CLIENT_TOKEN";private readonly UserManager _userManager;private readonly ISettingManager settingManager;private readonly SmsCaptchaManager smsCaptchaManager;private readonly EmailCaptchaManager emailCaptchaManager;public TwoFactorAuthorizationManager(UserManager userManager,ISettingManager settingManager,SmsCaptchaManager smsCaptchaManager,EmailCaptchaManager emailCaptchaManager){this._userManager = userManager;this.settingManager = settingManager;this.smsCaptchaManager = smsCaptchaManager;this.emailCaptchaManager = emailCaptchaManager;}public async Task<bool> IsTwoFactorAuthRequiredAsync(AbpLoginResult<Tenant, User> loginResult, string TwoFactorRememberClientToken, TokenValidationParameters validationParameters){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;}if (await TwoFactorClientRememberedAsync(loginResult.User.ToUserIdentifier(), TwoFactorRememberClientToken, validationParameters)){return false;}return true;}public async Task<bool> TwoFactorClientRememberedAsync(UserIdentifier userIdentifier, string TwoFactorRememberClientToken, TokenValidationParameters validationParameters){if (!await settingManager.GetSettingValueAsync<bool>(AbpZeroSettingNames.UserManagement.TwoFactorLogin.IsRememberBrowserEnabled)){return false;}if (string.IsNullOrWhiteSpace(TwoFactorRememberClientToken)){return false;}try{var tokenHandler = new JwtSecurityTokenHandler();if (tokenHandler.CanReadToken(TwoFactorRememberClientToken)){try{SecurityToken validatedToken;var principal = tokenHandler.ValidateToken(TwoFactorRememberClientToken, validationParameters, out validatedToken);var userIdentifierString = principal.Claims.First(c => c.Type == TwoFactorAuthorizationManager.USER_IDENTIFIER_CLAIM);if (userIdentifierString == null){throw new SecurityTokenException(TwoFactorAuthorizationManager.USER_IDENTIFIER_CLAIM + " invalid");}var tokenValidityKeyInClaims = principal.Claims.First(c => c.Type == TwoFactorAuthorizationManager.REMEMBER_CLIENT_TOKEN);var currentUserIdentifier = UserIdentifier.Parse(userIdentifierString.Value);var user = _userManager.GetUserById(currentUserIdentifier.UserId);var isValidityKetValid = AsyncHelper.RunSync(() => _userManager.IsTokenValidityKeyValidAsync(user, tokenValidityKeyInClaims.Value));if (!isValidityKetValid){throw new SecurityTokenException(REMEMBER_CLIENT_TOKEN + " invalid");}return userIdentifierString.Value == userIdentifier.ToString();}catch (Exception ex){LogHelper.LogException(ex);}}}catch (Exception ex){LogHelper.LogException(ex);}return false;}public async Task<string> TwoFactorAuthenticateAsync(User user, string token, string provider, bool rememberClient, TokenValidationParameters validationParameters){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");}if (rememberClient){if (await settingManager.GetSettingValueAsync<bool>(AbpZeroSettingNames.UserManagement.TwoFactorLogin.IsRememberBrowserEnabled)){var expiration = TimeSpan.FromDays(7);var tokenValidityKey = Guid.NewGuid().ToString("N");var accessToken = CreateAccessToken(new[]{new Claim(USER_IDENTIFIER_CLAIM, user.ToUserIdentifier().ToString()),new Claim(REMEMBER_CLIENT_TOKEN, tokenValidityKey)}, validationParameters);await _userManager.AddTokenValidityKeyAsync(user, tokenValidityKey,DateTime.Now.Add(expiration));return accessToken;}}return null;}private string CreateAccessToken(IEnumerable<Claim> claims, TokenValidationParameters validationParameters){var now = DateTime.UtcNow;var expiration = TimeSpan.FromDays(7);var signingCredentials = new SigningCredentials(validationParameters.IssuerSigningKey, SecurityAlgorithms.HmacSha256);var jwtSecurityToken = new JwtSecurityToken(issuer: validationParameters.ValidIssuer,audience: validationParameters.ValidAudience,claims: claims,notBefore: now,expires: now.Add(expiration),signingCredentials: signingCredentials);return new JwtSecurityTokenHandler().WriteToken(jwtSecurityToken);}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("验证码提供者错误");}}}

至此我们就完成了后端部分的开发

修改前端

登录

在两步验证的页面中添加一个checkbox，用于选择是否记住客户端

<el-checkbox v-model="loginForm.rememberClient">7天内不再要求两步验证
</el-checkbox>

JavaScript部分添加对rememberClientToken的处理，存储于cookie中，即便在网页刷新后也能保持免两步验证的状态

const rememberClientTokenKey = "main_rememberClientToken";
const setRememberClientToken = (rememberClientToken: string) =>Cookies.set(rememberClientTokenKey, rememberClientToken);
const cleanRememberClientToken = () => Cookies.remove(rememberClientTokenKey);
const getRememberClientToken = () => Cookies.get(rememberClientTokenKey);

在请求body中添加rememberClientToken, rememberClient的值

 var rememberClientToken = getRememberClientToken();
var rememberClient=this.loginForm.rememberClient;userNameOrEmailAddress = userNameOrEmailAddress.trim();
await request(`${this.host}api/TokenAuth/Authenticate`, "post", {userNameOrEmailAddress,password,twoFactorAuthenticationToken,twoFactorAuthenticationProvider,rememberClientToken,rememberClient
})

请求成功后，返回报文中包含rememberClientToken，将其存储于cookie中

setRememberClientToken(data.rememberClientToken);

登出

登出的逻辑不用做其他的修改，只需要将页面的两步验证的token清空即可，

this.loginForm.twoFactorAuthenticationToken = "";
this.loginForm.password = "";

rememberClientToken是存储于cookie中的，当用户登出时不需要清空cookie中的rememberClientToken，以便下次登录跳过两步验证

除非在浏览器设置中清空cookie，下次登录时，rememberClientToken就会失效。

最终效果

项目地址

Github:matoapp-samples