.net core webapi jwt 更为清爽的认证详解

我的方式非主流，控制却可以更加灵活，喜欢的朋友，不妨花一点时间学习一下

jwt认证分为两部分，第一部分是加密解密，第二部分是灵活的应用于中间件，我的处理方式是将获取token放到api的一个具体的controller中，将发放token与验证分离，token的失效时间，发证者，使用者等信息存放到config中。

1.配置：

在appsettings.json中增加配置

"Jwt": {
"Issuer": "issuer",//随意定义
"Audience": "Audience",//随意定义
"SecretKey": "abc",//随意定义
"Lifetime": 20, //单位分钟
"ValidateLifetime": true,//验证过期时间
"HeadField": "useless", //头字段
"Prefix": "prefix", //前缀
"IgnoreUrls": [ "/Auth/GetToken" ]//忽略验证的url
}

2:定义配置类：

internal class JwtConfig
  {
    public string Issuer { get; set; }
    public string Audience { get; set; }

    /// 

    /// 加密key
    /// 
    public string SecretKey { get; set; }
    /// 

    /// 生命周期
    /// 
    public int Lifetime { get; set; }
    /// 

    /// 是否验证生命周期
    /// 
    public bool ValidateLifetime { get; set; }
    /// 

    /// 验证头字段
    /// 
    public string HeadField { get; set; }
    /// 

    /// jwt验证前缀
    /// 
    public string Prefix { get; set; }
    /// 

    /// 忽略验证的url
    /// 
    public List IgnoreUrls { get; set; }
  }

3.加密解密接口：

 public interface IJwt
  {
    string GetToken(Dictionary Clims);
    bool ValidateToken(string Token,out Dictionary Clims);
  }

4.加密解密的实现类：

install -package System.IdentityModel.Tokens.Jwt

 public class Jwt : IJwt
  {
    private IConfiguration _configuration;
    private string _base64Secret;
    private JwtConfig _jwtConfig = new JwtConfig();
    public Jwt(IConfiguration configration)
    {
      this._configuration = configration;
      configration.GetSection("Jwt").Bind(_jwtConfig);
      GetSecret();
    }
    /// 

    /// 获取到加密串
    /// 
    private void GetSecret()
    {
      var encoding = new System.Text.ASCIIEncoding();
      byte[] keyByte = encoding.GetBytes("salt");
      byte[] messageBytes = encoding.GetBytes(this._jwtConfig.SecretKey);
      using (var hmacsha256 = new HMACSHA256(keyByte))
      {
 byte[] hashmessage = hmacsha256.ComputeHash(messageBytes);
 this._base64Secret= Convert.Tobase64String(hashmessage);
      }
    }
    /// 

    /// 生成Token
    /// 
    /// 
    /// 
    public string GetToken(Dictionary Claims)
    {
      List claimsAll = new List();
      foreach (var item in Claims)
      {
 claimsAll.Add(new Claim(item.Key, item.Value));
      }
      var symmetricKey = Convert.Frombase64String(this._base64Secret);
      var tokenHandler = new JwtSecurityTokenHandler();
      var tokenDescriptor = new SecurityTokenDescriptor
      {
 Issuer = _jwtConfig.Issuer,
 Audience = _jwtConfig.Audience,
 Subject = new ClaimsIdentity(claimsAll),
 NotBefore = DateTime.Now,
 Expires = DateTime.Now.AddMinutes(this._jwtConfig.Lifetime),
 SigningCredentials =new SigningCredentials(new SymmetricSecurityKey(symmetricKey),
 SecurityAlgorithms.HmacSha256Signature)
      };
      var securityToken = tokenHandler.CreateToken(tokenDescriptor);
      return tokenHandler.WriteToken(securityToken);
    }
    public bool ValidateToken(string Token, out Dictionary Clims)
    {
      Clims = new Dictionary();
      ClaimsPrincipal principal = null;
      if (string.IsNullOrWhiteSpace(Token))
      {
 return false;
      }
      var handler = new JwtSecurityTokenHandler();
      try
      {
 var jwt = handler.ReadJwtToken(Token);

 if (jwt == null)
 {
   return false;
 }
 var secretBytes = Convert.Frombase64String(this._base64Secret);
 var validationParameters = new TokenValidationParameters
 {
   RequireExpirationTime = true,
   IssuerSigningKey = new SymmetricSecurityKey(secretBytes),
   ClockSkew = TimeSpan.Zero,
   ValidateIssuer = true,//是否验证Issuer
   ValidateAudience = true,//是否验证Audience
   ValidateLifetime = this._jwtConfig.ValidateLifetime,//是否验证失效时间
   ValidateIssuerSigningKey = true,//是否验证SecurityKey
   ValidAudience = this._jwtConfig.Audience,
   ValidIssuer = this._jwtConfig.Issuer
 };
 SecurityToken securityToken;
 principal = handler.ValidateToken(Token, validationParameters, out securityToken);
 foreach (var item in principal.Claims)
 {
   Clims.Add(item.Type, item.Value);
 }
 return true;
      }
      catch (Exception ex)
      {
 return false;
      }
    }
  }

5.定义获取Token的Controller:

在Startup.ConfigureServices中注入 IJwt

services.AddTransient(); // Jwt注入

[Route("[controller]/[action]")]
  [ApiController]
  public class AuthController : Controllerbase
  {
    private IJwt _jwt;
    public AuthController(IJwt jwt)
    {
      this._jwt = jwt;
    }
    /// 

    /// getToken
    /// 
    /// 
    [HttpPost]
    public IActionResult GetToken()
    {
      if (true)
      {
 Dictionary clims = new Dictionary();
 clims.Add("userName", userName);
 return new JsonResult(this._jwt.GetToken(clims));
      }
    }
  }

6.创建中间件：

 public class UseJwtMiddleware
  {
    private readonly RequestDelegate _next;
    private JwtConfig _jwtConfig =new JwtConfig();
    private IJwt _jwt;
    public UseJwtMiddleware(RequestDelegate next, IConfiguration configration,IJwt jwt)
    {
      _next = next;
      this._jwt = jwt;
      configration.GetSection("Jwt").Bind(_jwtConfig);
    }
    public Task InvokeAsync(HttpContext context)
    {
      if (_jwtConfig.IgnoreUrls.Contains(context.Request.Path))
      {
 return this._next(context);
      }
      else
      {
 if (context.Request.Headers.TryGetValue(this._jwtConfig.HeadField, out Microsoft.Extensions.Primitives.StringValues authValue))
 {
   var authstr = authValue.ToString();
   if (this._jwtConfig.Prefix.Length > 0)
   {
     authstr = authValue.ToString().Substring(this._jwtConfig.Prefix.Length+1, authValue.ToString().Length -(this._jwtConfig.Prefix.Length+1));
   }
   if (this._jwt.ValidateToken(authstr, out Dictionary Clims))
   {
     foreach (var item in Clims)
     {
context.Items.Add(item.Key, item.Value);
     }
     return this._next(context);
   }
   else
   {
     context.Response.StatusCode = 401;
     context.Response.ContentType = "application/json";
     return context.Response.WriteAsync("{"status":401,"statusMsg":"auth vaild fail"}");
   }
 }
 else
 {
   context.Response.StatusCode = 401;
   context.Response.ContentType = "application/json";
   return context.Response.WriteAsync("{"status":401,"statusMsg":"auth vaild fail"}");
 }
      }
    }
  }

7.中间件暴露出去

public static class UseUseJwtMiddlewareExtensions
  {
    /// 

    /// 权限检查
    /// 
    /// 
    /// 
    public static IApplicationBuilder UseJwt(this IApplicationBuilder builder)
    {
      return builder.UseMiddleware();
    }
  }

8.在Startup.Configure中使用中间件：

app.UseJwt();

以1的配置为例：

除了请求 /auth/getToken 不需要加头信息外，其他的请求一律要求头信息中必须带着

userless:prefix (从Auth/GetToken中获取到的token)

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持考高分网。