asp.net core 3.1 自定義中間件實現jwt token認證

話不多講，也不知道咋講！直接上代碼

認證信息承載對象【user】

/// <summary>
/// 認證用戶信息
/// </summary>
public class DyUser
{
    /// <summary>
    /// 用戶ID
    /// </summary>
    public int UserId { get; set; }
    /// <summary>
    /// 所屬商戶ID
    /// </summary>
    public int? TenantId { get; set; }
}

Jwt配置對象

public class AuthOptions
{
    /// <summary>
    /// Jwt認證Key
    /// </summary>
    public string Security { get; set; }
    /// <summary>
    /// 過期時間【天】
    /// </summary>
    public int Expiration { get; set; }
}

JWT管理接口

public interface IAuthManage
{
    /// <summary>
    /// 生成JwtToken
    /// </summary>
    /// <param name="user">用戶信息</param>
    /// <returns></returns>
    string GenerateJwtToken(DyUser user);
}

JWT管理接口實現

暫時是使用微軟提供類庫生成，如果有想法可以自己生成

public class MicrosoftJwtAuthManage : IAuthManage
{
    private readonly AuthOptions _authOptions;
    public MicrosoftJwtAuth(AuthOptions authOptions)
    {
        _authOptions = authOptions;
    }

    public string GenerateJwtToken(DyUser user)
    {
        var tokenHandler = new JwtSecurityTokenHandler();
        var key = Encoding.ASCII.GetBytes(_authOptions.Security);
        var tokenDescriptor = new SecurityTokenDescriptor
        {
            Subject = new ClaimsIdentity(new Claim[]
            {
                new Claim("user",user.ToJson())
            }),
            Expires = DateTime.UtcNow.AddDays(_authOptions.Expiration),//一周過期
            SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(key), SecurityAlgorithms.HmacSha256Signature)
        };
        var token = tokenHandler.CreateToken(tokenDescriptor);
        return tokenHandler.WriteToken(token);
    }
}

處理JWT中間件

這里借鑒國外大牛的代碼，主要就是驗證jwt並且存把解析出來的數據存放到當前上下文

public class JwtMiddleware
{
    private readonly RequestDelegate _next;
    private readonly AuthOptions _authOptions;

    public JwtMiddleware(RequestDelegate next, AuthOptions authOptions)
    {
        _next = next;
        _authOptions = authOptions;
    }

    public async Task Invoke(HttpContext context)
    {
        //獲取上傳token，可自定義擴展
        var token = context.Request.Headers["Authorization"].FirstOrDefault()?.Split(" ").Last()
                    ?? context.Request.Headers["X-Token"].FirstOrDefault()
                    ?? context.Request.Query["Token"].FirstOrDefault()
                    ?? context.Request.Cookies["Token"];

        if (token != null)
            AttachUserToContext(context, token);

        await _next(context);
    }

    private void AttachUserToContext(HttpContext context, string token)
    {
        try
        {
            var tokenHandler = new JwtSecurityTokenHandler();
            var key = Encoding.ASCII.GetBytes(_authOptions.Security);
            tokenHandler.ValidateToken(token, new TokenValidationParameters
            {
                ValidateIssuerSigningKey = true,
                IssuerSigningKey = new SymmetricSecurityKey(key),
                ValidateIssuer = false,
                ValidateAudience = false,
                // set clockskew to zero so tokens expire exactly at token expiration time (instead of 5 minutes later)
                ClockSkew = TimeSpan.Zero
            }, out SecurityToken validatedToken);

            var jwtToken = (JwtSecurityToken)validatedToken;
            var user = jwtToken.Claims.First(x => x.Type == "user").Value.ToJsonEntity<DyUser>();

            //寫入認證信息，方便業務類使用
            var claimsIdentity = new ClaimsIdentity(new Claim[] { new Claim("user", jwtToken.Claims.First(x => x.Type == "user").Value) });
            Thread.CurrentPrincipal = new ClaimsPrincipal(claimsIdentity);

            // attach user to context on successful jwt validation
            context.Items["User"] = user;
        }
        catch
        {
            // do nothing if jwt validation fails
            // user is not attached to context so request won't have access to secure routes
        }
    }
}

權限過濾器

這個根據剛才中間件的存放的信息判斷是否授權成功，支持匿名特性

public class ApiAuthorizeAttribute : Attribute, IAuthorizationFilter
{
    public void OnAuthorization(AuthorizationFilterContext context)
    {
        var user = context.HttpContext.Items["User"];
        //驗證是否需要授權和授權信息
        if (HasAllowAnonymous(context) == false && user == null)
        {
            // not logged in
            context.Result = new JsonResult(new {message = "Unauthorized"})
                {StatusCode = StatusCodes.Status401Unauthorized};
        }
    }

    private static bool HasAllowAnonymous(AuthorizationFilterContext context)
    {
        var filters = context.Filters;
        if (filters.OfType<IAllowAnonymousFilter>().Any())
        {
            return true;
        }

        // When doing endpoint routing, MVC does not add AllowAnonymousFilters for AllowAnonymousAttributes that
        // were discovered on controllers and actions. To maintain compat with 2.x,
        // we'll check for the presence of IAllowAnonymous in endpoint metadata.
        var endpoint = context.HttpContext.GetEndpoint();
        return endpoint?.Metadata?.GetMetadata<IAllowAnonymous>() != null;
    }
}

擴展IServiceCollection

方便以后管理和維護，主要就是把需要的對象注入到IOC容器里面

public static class AuthServiceExtensions
{
    public static void AddAuth(this IServiceCollection services, Action<AuthOptions> configAction)
    {
        var options = new AuthOptions();
        configAction(options);
        services.AddSingleton(options);
        services.AddSingleton<IAuthManage>(new MicrosoftJwtAuthManage(options));
    }
}

NullDySession

這里是為了在非控制器類獲取用戶信息用

/// <summary>
/// 當前會話對象
/// </summary>
public class NullDySession
{
    /// <summary>
    /// 獲取DySession實例
    /// </summary>
    public static NullDySession Instance { get; } = new NullDySession();
    /// <summary>
    /// 獲取當前用戶信息
    /// </summary>
    public DyUser DyUser
    {
        get
        {
            var claimsPrincipal = Thread.CurrentPrincipal as ClaimsPrincipal;

            var claimsIdentity = claimsPrincipal?.Identity as ClaimsIdentity;

            var userClaim = claimsIdentity?.Claims.FirstOrDefault(c => c.Type == "user");
            if (userClaim == null || string.IsNullOrEmpty(userClaim.Value))
            {
                return null;
            }

            return userClaim.Value.ToJsonEntity<DyUser>();
        }
    }

    private NullDySession()
    {
    }
}

---

到這為止准備工作完成，開始用起來吧~

修改【Startup.cs->ConfigureServices】

//添加全局權限認證過濾器
services.AddControllersWithViews(options =>
{
	options.Filters.Add<ApiAuthorizeAttribute>();
})
//添加認證配置信息
services.AddAuth(options =>
{
	options.Expiration = 7;//天為單位
	options.Security = apolloConfig.Get("JwtSecret");
});

添加中間件【Startup.cs->Configure(IApplicationBuilder app, IWebHostEnvironment env)方法中】

注意中間件的位置

//啟用jwt認證中間件
app.UseMiddleware<JwtMiddleware>();

api使用案例【使用構造注入IAuthManage】

//生成了JwtToken
var token = _authManage.GenerateJwtToken(new DyUser {UserId = userId, TenantId = tenantId});

//Controller里面獲取用戶信息
public DyUser DyUser => (DyUser)this.HttpContext.Items["User"];

//普通class類獲取用戶信息【如果不是Web應用，需要獨立引用Dymg.Core】
NullDySession.Instance.DyUser.UserId;

//如果個別不接口不需要認證，可以使用AllowAnonymous特性
[HttpPost, AllowAnonymous]
public string Noauth()
{
	return "這個不需要授權";
}

前端調用案例

//token放在請求頭里面
Authorization:Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VyIjoie1wiVXNlcklkXCI6MTIzNDU2ODcsXCJUZW5hbnRJZFwiOjY1NDMyMSxcIlN0YXRpb25JZFwiOm51bGwsXCJTbWFydEJveFNuXCI6bnVsbH0iLCJuYmYiOjE1OTU5MDAxMzYsImV4cCI6MTU5NjUwNDkzNiwiaWF0IjoxNTk1OTAwMTM2fQ.lkEunspinGeQK9sFoQs2WLpNticqOR4xv_18CQdOE_Y
//自定義key
x-token:eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VyIjoie1wiVXNlcklkXCI6MTIzNDU2ODcsXCJUZW5hbnRJZFwiOjY1NDMyMSxcIlN0YXRpb25JZFwiOm51bGwsXCJTbWFydEJveFNuXCI6bnVsbH0iLCJuYmYiOjE1OTU5MDAxMzYsImV4cCI6MTU5NjUwNDkzNiwiaWF0IjoxNTk1OTAwMTM2fQ.lkEunspinGeQK9sFoQs2WLpNticqOR4xv_18CQdOE_Y

//使用連接字符串方式
https://xxxxx/user/getUser?token=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VyIjoie1wiVXNlcklkXCI6MTIzNDU2ODcsXCJUZW5hbnRJZFwiOjY1NDMyMSxcIlN0YXRpb25JZFwiOm51bGwsXCJTbWFydEJveFNuXCI6bnVsbH0iLCJuYmYiOjE1OTU5MDAxMzYsImV4cCI6MTU5NjUwNDkzNiwiaWF0IjoxNTk1OTAwMTM2fQ.lkEunspinGeQK9sFoQs2WLpNticqOR4xv_18CQdOE_Y