前言
许久没写博文了，整合下这段时间所学吧，前进路上总要停下来回顾下学习成果。
本篇记录下项目的权限验证，WebApi项目中用权限验证来保证接口安全总是需要的，然而权限验证的方式多种多样，博主在项目中使用的多的也就是JWT了，一般都是写完之后万年不动~~
所以，本篇算是对鉴权授权的回顾与总结
JWT
至于什么是JWT(https://jwt.io/)，只要不是小白都知道吧，不知道的去看下JWT的结构原理这些，偷偷补下课，JWT(JSON Web Token)名字可看出来这是Json格式的web凭证，也就是一个令牌，只有拿到这个Token才能访问到接口，否则请求接口之后会返回401HTTP状态码，401状态码表示未授权，而想要拿到服务器的Token，必须通过服务器验证，一般这个验证来自登录之后返回出来，如果是开发平台一般是通过AppId和Secrect来获取到Token，获取到Token后将Token添加到请求头中，服务器收到请求后，获取到请求头的Token后一验证，“诶！~是我发布的Token，通过！”，随后才能进入控制器。
引入
先把JWT引入到项目中来,目前最新版本为稳定版5.0.2
nuget : Microsoft.AspNetCore.Authentication.JwtBearer
鉴权授权
首先要知道沃恩需要什么样的鉴权策略，在生成Token时的策略就必须保持一致。在WebApi中我们不知道是谁在访问服务器，当然想要知道还是可以的，这时可以通过Token将用户信息传到服务器，我们知道JWT的负载信息除了已经准备好的"sub"、"name"、"iat"这些信息，我们还能自定义我们需要的字段，比如登录人的UserId，UserName，AppId等……
首先需要一个接口 IAuthService
public interface IAuthService
{
/// <summary>
/// 判断权限
/// </summary>
/// <param name="token"></param>
/// <param name="path"></param>
/// <returns></returns>
Task<bool> PermissionAsync(string token, string path);
/// <summary>
/// 获取用户
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
Task SetUserAsync(string token);
}
以后所有的权限类型都可以使用这个接口，先将JWT需要的类包装下，这样就能直接使用了
public static class JwtUtils
{
/// <summary>
/// 生成token
/// </summary>
/// <param name="claims"></param>
/// <returns></returns>
public static string CreateToken(IEnumerable<Claim> claims, string securityKey)
{
var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(securityKey));
var creds = new SigningCredentials(key, SecurityAlgorithms.HmacSha512);
var securityToken = new JwtSecurityToken(
issuer: null,
audience: null,
claims: claims,
//expires: DateTime.Now.AddMinutes(settings.ExpMinutes),
signingCredentials: creds);
var token = new JwtSecurityTokenHandler().WriteToken(securityToken);
return token;
}
/// <summary>
/// 生成Jwt
/// </summary>
/// <param name="userName"></param>
/// <param name="roleName"></param>
/// <param name="userId"></param>
/// <returns></returns>
public static string GenerateToken(string userId, string securityKey)
{
//声明claim
var claims = new Claim[] {
new Claim(JwtRegisteredClaimNames.Typ,"JWT"),
new Claim(JwtRegisteredClaimNames.Sub, userId),
new Claim(JwtRegisteredClaimNames.Iat,DateTimeOffset.UtcNow.ToUnixTimeSeconds().ToString(),ClaimValueTypes.Integer64),
new Claim(JwtRegisteredClaimNames.Exp, DateTimeOffset.UtcNow.AddMonths(2).ToUnixTimeSeconds().ToString(), ClaimValueTypes.Integer64), //过期时间
};
return CreateToken(claims, securityKey);
}
///// <summary>
///// 刷新token
///// </summary>
///// <returns></returns>
//public static string RefreshToken(string oldToken)
//{
// var pl = GetPayload(oldToken);
// //声明claim
// var claims = new Claim[] {
// new Claim(JwtRegisteredClaimNames.Sub, pl?.UserName),
// new Claim(JwtRegisteredClaimNames.Jti, pl?.UserId),
// new Claim(JwtRegisteredClaimNames.Iat, DateTime.UtcNow.ToUnixDate().ToString(), ClaimValueTypes.Integer64),//签发时间
// new Claim(JwtRegisteredClaimNames.Nbf, DateTime.UtcNow.ToUnixDate().ToString(), ClaimValueTypes.Integer64),//生效时间
// new Claim(JwtRegisteredClaimNames.Exp, DateTime.Now.AddMinutes(settings.ExpMinutes).ToUnixDate().ToString(), ClaimValueTypes.Integer64), //过期时间
// new Claim(JwtRegisteredClaimNames.Iss, settings.Issuer),
// new Claim(JwtRegisteredClaimNames.Aud, settings.Audience),
// new Claim(ClaimTypes.Name, pl?.UserName),
// new Claim(ClaimTypes.Role, pl?.RoleId),
// new Claim(ClaimTypes.Sid, pl?.UserId)
// };
// return IsExp(oldToken) ? CreateToken(claims) : null;
//}
/// <summary>
/// 从token中获取用户身份
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
public static IEnumerable<Claim> GetClaims(string token)
{
var handler = new JwtSecurityTokenHandler();
var securityToken = handler.ReadJwtToken(token);
return securityToken?.Claims;
}
/// <summary>
/// 从Token中获取用户身份
/// </summary>
/// <param name="token"></param>
/// <param name="securityKey">securityKey明文,Java加密使用的是Base64</param>
/// <returns></returns>
public static ClaimsPrincipal GetPrincipal(string token, string securityKey)
{
try
{
var handler = new JwtSecurityTokenHandler();
TokenValidationParameters tokenValidationParameters = new TokenValidationParameters
{
ValidateAudience = false,
ValidateIssuer = false,
ValidateIssuerSigningKey = true,
IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(securityKey)),
ValidateLifetime = false
};
return handler.ValidateToken(token, tokenValidationParameters, out SecurityToken validatedToken);
}
catch (Exception ex)
{
return null;
}
}
/// <summary>
/// 校验Token
/// </summary>
/// <param name="token">token</param>
/// <returns></returns>
public static bool CheckToken(string token, string securityKey)
{
var principal = GetPrincipal(token, securityKey);
if (principal is null)
{
return false;
}
return true;
}
/// <summary>
/// 获取Token中的载荷数据
/// </summary>
/// <param name="token">token</param>
/// <returns></returns>
public static JwtPayload GetPayload(string token)
{
var jwtHandler = new JwtSecurityTokenHandler();
JwtSecurityToken securityToken = jwtHandler.ReadJwtToken(token);
return new JwtPayload
{
sub = securityToken.Payload[JwtRegisteredClaimNames.Sub]?.ToString(),
exp = DateTimeOffset.FromUnixTimeSeconds(long.Parse(securityToken.Payload[JwtRegisteredClaimNames.Exp].ToString())).ToLocalTime().DateTime,
iat = securityToken.Payload[JwtRegisteredClaimNames.Iat]?.ToString()
};
}
/// <summary>
/// 获取Token中的载荷数据
/// </summary>
/// <typeparam name="T">泛型</typeparam>
/// <param name="token">token</param>
/// <returns></returns>
public static T GetPayload<T>(string token)
{
var jwtHandler = new JwtSecurityTokenHandler();
JwtSecurityToken jwtToken = jwtHandler.ReadJwtToken(token);
return JsonConvert.DeserializeObject<T>(jwtToken.Payload.SerializeToJson());
}
/// <summary>
/// 判断token是否过期
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
public static bool IsExp(string token)
{
return false;
//return GetPrincipal(token)?.Claims.First(c => c.Type == JwtRegisteredClaimNames.Exp)?.Value?.TimeStampToDate() < DateTime.Now;
//return GetPayload(token).ExpTime < DateTime.Now;
}
}
/// <summary>
/// Jwt载荷信息
/// </summary>
public class JwtPayload
{
public string sub { get; set; }
public string iat { get; set; }
public DateTime exp { get; set; }
}
JWT服务实现
public class AuthSettings
{
public string Secret { get; set; }
public string Issuer { get; set; }
public double Expire { get; set; }
}
public class AuthServiceImpl : IAuthService
{
private readonly AuthSettings _authSettings;
private readonly LoginUser _currentUser;
public AuthServiceImpl(IOptions<AuthSettings> authSettings, LoginUser currentUser)
{
_authSettings = authSettings.Value;
_currentUser = currentUser;
}
public Task<bool> PermissionAsync(string token)
{
return Task.FromResult(JwtUntil.CheckToken(token, _authSettings.Secret));
}
public Task SetUserAsync(string token)
{
var payload = JwtUntil.GetPayload(token);
_currentUser.UserId = payload.UserId;
_currentUser.RoleType = payload.Role;
return Task.CompletedTask;
}
}
说到这还没有注册JWT，我们先注册到项目中，验证策略自己定，记得要先注入下服务
services.AddScoped<IAuthService, AuthServiceImpl>();
services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
.AddJwtBearer(x =>
{
x.RequireHttpsMetadata = false;//元数据地址或权限是否需要https
x.SaveToken = true;//是否将存储信息保存在token中
x.TokenValidationParameters = new Microsoft.IdentityModel.Tokens.TokenValidationParameters
{
ValidateLifetime = true,//是否验证过期时间
LifetimeValidator = (notBefore, expire, securityToken, validationparameters) =>
{
bool t = DateTime.UtcNow < expire;
return t;
},
ValidateAudience = false,//是否验证被发布者
ValidateIssuer = true,//是否验证发布者
ValidIssuer = configuration["AuthSettings:Issuer"],
ValidateIssuerSigningKey = true,//是否验证签名
IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(configuration["AuthSettings:Secret"]))
};
});
#region 授权鉴权 /授权 app.UseAuthentication(); //鉴权 app.UseAuthorization(); #endregion
接下来就是设置当前登录用户，获取当前登录用户：发布时在 claims中加入自定义的UserId等信息，授权时获取当前Token解析claims中用户信息属性即可获取到当前请求用户。
本项目中使用的是一个中间件
public sealed class LoginMiddlerware
{
private readonly RequestDelegate _next;
public LoginMiddlerware(RequestDelegate next)
{
_next = next;
}
/// <summary>
/// 设置登录用户
/// </summary>
/// <param name="context"></param>
/// <param name="_authService"></param>
/// <returns></returns>
public async Task InvokeAsync(HttpContext context, IEnumerable<IAuthService> _authService)
{
string token = GetToken();
if (!string.IsNullOrEmpty(token))
{
if (token.StartsWith("Bearer", StringComparison.OrdinalIgnoreCase) || token.Contains('.'))
{
await _authService.First(a => a.ServiceName == nameof(JwtAuthServiceImpl)).SetUserAsync(token);
}
else if (token.StartsWith("App", StringComparison.OrdinalIgnoreCase))
{
await _authService.First(a => a.ServiceName == nameof(AppAuthServiceImpl)).SetUserAsync(token);
}
else
{
await _authService.First(a => a.ServiceName == nameof(OauthAuthServiceImpl)).SetUserAsync(token);
}
}
await _next.Invoke(context);
string GetToken()
{
string token = context.Request.Headers["token"];
if (string.IsNullOrEmpty(token))
{
token = context.Request.Query["token"];
}
return token;
}
}
}
到这里JWt就差不多讲完了，接下来是使用，使用时无非就是在控制器或方法上打上标记，如要同时兼容多种授权方式，可以自己写一个Attribute
/// <summary>
/// 自定义授权验证特性
/// </summary>
public class RequiresPermissionsAttribute : TypeFilterAttribute
{
public RequiresPermissionsAttribute(ClaimType claimType, string claimValue = "") : base(typeof(ClaimRequirementFilter))
{
Arguments = new object[] { new Claim(claimType.ToString(), claimValue) };
}
}
public class ClaimRequirementFilter : IAuthorizationFilter
{
readonly Claim _claim;
readonly IEnumerable<IAuthService> _authService;
private readonly WinkSignSettings _winkSignSettings;
public ClaimRequirementFilter(Claim claim, IEnumerable<IAuthService> authService, IOptions<WinkSignSettings> winkSignSettings)
{
_claim = claim;
_authService = authService;
_winkSignSettings = winkSignSettings.Value;
}
public void OnAuthorization(AuthorizationFilterContext context)
{
ControllerActionDescriptor controllerActionDescriptor = context.ActionDescriptor as ControllerActionDescriptor;
if (controllerActionDescriptor != null)
{
var skipAuthorization = controllerActionDescriptor.MethodInfo.GetCustomAttributes(inherit: true)
.Any(a => a.GetType().Equals(typeof(AllowAnonymousAttribute)));
if (skipAuthorization)
{
return;
}
}
ClaimType claimType = Enum.Parse<ClaimType>(_claim.Type);
bool permission = false;
string token = GetToken();
if (string.IsNullOrEmpty(token))
{
context.Result = new UnauthorizedResult();
return;
}
if (claimType == ClaimType.JwtOrOauth2)
{
//根据Token类型选择认证方式
if (token.Any(t => t == '.'))
{
claimType = ClaimType.JWT;
}
else
{
claimType = ClaimType.Oauth2;
}
}
permission = claimType switch
{
ClaimType.Oauth2 or ClaimType.Cookie =>
_authService.First(a => a.ServiceName == nameof(OauthAuthServiceImpl)).PermissionAsync(token, _claim.Value).Result,
ClaimType.JWT =>
_authService.First(a => a.ServiceName == nameof(JwtAuthServiceImpl)).PermissionAsync(token, _claim.Value).Result,
ClaimType.Key =>
_authService.First(a => a.ServiceName == nameof(KeyAuthServiceImpl)).PermissionAsync(token, _claim.Value).Result,
ClaimType.App =>
_authService.First(a => a.ServiceName == nameof(AppAuthServiceImpl)).PermissionAsync(token, _claim.Value).Result,
};
if (!permission)
{
context.Result = new UnauthorizedResult();
return;
}
string GetToken()
{
string token = context.HttpContext.Request.Headers["token"];
if (string.IsNullOrEmpty(token))
{
token = context.HttpContext.Request.Query["token"];
}
if (string.IsNullOrEmpty(token))
{
context.HttpContext.Request.Cookies.TryGetValue("token", out token);
}
return token;
}
}
}
public enum ClaimType
{
Oauth2,
JWT,
Cookie,
Key,
App,
JwtOrOauth2
}
这样就能实现多个方式同时存在，想用哪个就用哪个了，只要实现 IAuthService 接口就行