/// <summary>
/// 获取JWT字符串并存入缓存
/// </summary>
/// <param name="tokenModel"></param>
/// <param name="expiresSliding"></param>
/// <param name="expiresAbsolute"></param>
/// <returns></returns>
public static string IssueJWT(TokenModel tokenModel, TimeSpan expiresSliding, TimeSpan expiresAbsolute)
{
DateTime dtUTC = DateTime.UtcNow;
Claim[] claims = new Claim[]
{
new Claim(JwtRegisteredClaimNames.Sub, tokenModel.Sub), //subject
new Claim(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString()), //JWT ID,JWT唯一标识
new Claim(JwtRegisteredClaimNames.Iat, dtUTC.ToString(), ClaimValueTypes.Integer64), //Issued At，JWT颁发的时间，采用标准unix时间，用于验证过期
};
JwtSecurityToken jwt = new JwtSecurityToken(
issuer: "NetCoreTest", //jwt签发者,非必须，自定义
audience: tokenModel.Uname, //jwt的接收方，非必须
claims: claims, //声明集合
expires: dtUTC.AddHours(12), //指定token的生命周期，unix时间戳格式,非必须
signingCredentials: new Microsoft.IdentityModel.Tokens.
SigningCredentials(new SymmetricSecurityKey(Encoding.ASCII.GetBytes("NetCoreTest's Secret Key")),
SecurityAlgorithms.HmacSha256)
);
var encodedJWT = new JwtSecurityTokenHandler().WriteToken(jwt);
NetCoreMemoryCache.AddMemoryCache(encodedJWT, tokenModel, expiresSliding, expiresAbsolute);//将JWT字符串，令牌实体，存入缓存
return(encodedJWT);
}
/// <summary>
/// 验证授权
/// </summary>
/// <param name="httpContext"></param>
/// <returns></returns>
public Task Invoke(HttpContext httpContext)
{
var headers = httpContext.Request.Headers;
//检测是否包含'Authorization'请求头，如果不包含返回context进行下一个中间件，用于访问不需要认证的API
if (!headers.ContainsKey("Authorization"))
{
return(_next(httpContext));
}
var tokenStr = headers["Authorization"];
try
{
string jwtStr = tokenStr.ToString().Trim();
//如果存在Authorization，但是和缓存的不一样，那就是被篡改了
if (!NetCoreMemoryCache.Exists(jwtStr))
{
return(httpContext.Response.WriteAsync("非法请求"));
}
TokenModel tm = (TokenModel)NetCoreMemoryCache.Get(jwtStr);
//提取tokenModel中的Sub属性进行authorize认证
List <Claim> lc = new List <Claim>();
Claim c = new Claim(tm.Sub + "Type", tm.Sub);
lc.Add(c);
ClaimsIdentity identity = new ClaimsIdentity(lc);
ClaimsPrincipal principal = new ClaimsPrincipal(identity);
httpContext.User = principal;
return(_next(httpContext));
}
catch (Exception)
{
return(httpContext.Response.WriteAsync("token验证异常"));
}
}