.net 使用Microsoft.IdentityModel.Tokens.Jwt进行身份认证

什么是JWT

JWT (全称:Json Web Token)是一个开放标准(RFC 7519),它定义了一种紧凑的、自包含的方式,用于作为 JSON 对象在各方之间安全地传输信息。该信息可以被验证和信任,因为它是数字签名的。

jwt和token区别

jwt和token区别主要体现在接收的信息是否需要进入数据库查询信息。.

服务端验证客户端发来的token信息要进行数据的查询操作；而JWT验证客户端发来的token信息不需要， JWT使用密钥校验不用数据库的查询。

.Net Core使用JWT

1、NUGET添加引用包

using Microsoft.IdentityModel.Tokens;
using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;

2、生成jwt字符串

public static string Loginjwt(long ID)
        {
            //引用System.IdentityModel.Tokens.Jwt
            DateTime utcNow = DateTime.UtcNow;

            SecurityKey securityKey = new SymmetricSecurityKey(Encoding.ASCII.GetBytes(key));

            var claims = new List<Claim>() {
                new Claim("ID",ID.ToString()),
                new Claim("Name","fan")
            };
            JwtSecurityToken jwtToken = new JwtSecurityToken(
                issuer: "fan",
                audience: "audi~~!",
                claims: claims,
                notBefore: utcNow,
                expires: utcNow.AddYears(1),
                signingCredentials: new SigningCredentials(securityKey, SecurityAlgorithms.HmacSha256)
                );

            //生成token方式1
            string jwtString = new JwtSecurityTokenHandler().WriteToken(jwtToken);

            return jwtString;
        }

3、对jwt进行校验和解析

 public static uint? Checkjwt(string jwtString)
        {
            SecurityKey securityKey = new SymmetricSecurityKey(Encoding.ASCII.GetBytes(key));

            //校验token
            var validateParameter = new TokenValidationParameters()
            {
                ValidateLifetime = true,
                ValidateAudience = true,
                ValidateIssuer = true,
                ValidateIssuerSigningKey = true,
                ValidIssuer = "fan",
                ValidAudience = "audi~~!",
                IssuerSigningKey = securityKey,
            };

            try
            {
                //校验并解析token
                var claimsPrincipal = new JwtSecurityTokenHandler().ValidateToken(jwtString, validateParameter, out SecurityToken validatedToken);//validatedToken:解密后的对象
                var jwtPayload = ((JwtSecurityToken)validatedToken).Payload.SerializeToJson(); //获取payload中的数据

                return Convert.ToUInt32(JsonHelper.GetObject<JwtRootobject>(jwtPayload).ID);
            }
            catch (SecurityTokenExpiredException)
            {
                //表示过期
                throw new Exception("登录过期");
            }
            catch (SecurityTokenException)
            {
                //表示token错误
                throw new Exception("token错误");
            }
            catch (Exception)
            {
                throw new Exception("验证失败");
            }

            //不校验，直接解析token
            //jwtToken = new JwtSecurityTokenHandler().ReadJwtToken(token1);
        }

4、针对请求进行头部验证Authorization

public override void OnActionExecuting(ActionExecutingContext context)
        {
            if (context.HttpContext.Request != null && context.HttpContext.Request.Headers != null && context.HttpContext.Request.Headers["Authorization"].Count > 0)
            {
                var token = context.HttpContext.Request.Headers["Authorization"];
                if (string.IsNullOrWhiteSpace(token))
                {
                    throw new CustomException("权限错误", ReturnCode.E1000004);
                }
                else
                {
                    if (!Getusergraphql(token))
                    {
                        throw new CustomException("权限错误", ReturnCode.E1000004);
                    }
                    //GenericIdentity ci = new GenericIdentity(token);
                    //ci.Label = "conan1111111";
                    //context.HttpContext.User = new GenericPrincipal(ci, null);
                }
            }
            else
            {
                throw new CustomException("权限错误", ReturnCode.E1000004);
            }

            base.OnActionExecuting(context);
        }

至此，我们完成了jwt的校验流程。