var PrivateKey =@"
			-----BEGIN RSA PRIVATE KEY-----
			...................................
			-----END RSA PRIVATE KEY-----
	    ";

	    //生成RSA私钥对象
	    var rsa = RSA.Create();
            var xmlPriKey = PemPrivateKey(PrivateKey);
            rsa.ImportParameters(xmlPriKey);
            SecurityKey key2 = new RsaSecurityKey(rsa);

	    //生成JWT密钥，授权
            var token = new JwtSecurityToken(
                issuer: "GATE",
                audience: "API",
                expires: exPriseDateTime,
                notBefore: DateTime.Now,
                claims: claims,
                signingCredentials: new SigningCredentials(key2, SecurityAlgorithms.RsaSha256)
                );

            var jwtToken = new JwtSecurityTokenHandler().WriteToken(token);
            return jwtToken;

	static RSAParameters PemPrivateKey(string pemPrivateKeyStr)
        {
            RsaPrivateCrtKeyParameters pemPrivateKey;
            using (var ms = new MemoryStream(Encoding.UTF8.GetBytes(pemPrivateKeyStr)))
            {
                using (var sr = new StreamReader(ms))
                {
		    //在.net中只支持XML格式的RSA密钥，所以需要借助第三方库才能识别PEM格式的密钥
                    var pemReader = new Org.BouncyCastle.OpenSsl.PemReader(sr);
                    var keyPair = (AsymmetricCipherKeyPair)pemReader.ReadObject();
                    pemPrivateKey = (RsaPrivateCrtKeyParameters)keyPair.Private;
                }
            }

            var p = new RSAParameters
            {
                Modulus = pemPrivateKey.Modulus.ToByteArrayUnsigned(),
                Exponent = pemPrivateKey.PublicExponent.ToByteArrayUnsigned(),
                D = pemPrivateKey.Exponent.ToByteArrayUnsigned(),
                P = pemPrivateKey.P.ToByteArrayUnsigned(),
                Q = pemPrivateKey.Q.ToByteArrayUnsigned(),
                DP = pemPrivateKey.DP.ToByteArrayUnsigned(),
                DQ = pemPrivateKey.DQ.ToByteArrayUnsigned(),
                InverseQ = pemPrivateKey.QInv.ToByteArrayUnsigned(),
            };
            return p;
        }

var Jwt:Prikey = "去掉开头和结束的标记，以及换行和空格符".replace("\r","").replace("\n","").replace(" ","").replace("BEGIN RSA PRIVATE KEY","").replace("END RSA PRIVATE KEY","");

[AllowAnonymous]
        public Task<string> GetToken()
        {
            var configurationBuilder = new ConfigurationBuilder().AddJsonFile("appsettings.json");
            var configuration = configurationBuilder.Build();

            List<Claim> claims = new List<Claim>();
            claims.Add(new Claim(ClaimTypes.Name, "name"));
            claims.Add(new Claim("ID", "123456"));
	    //生成RSA私钥实例
            var rsa = RSA.Create();

            //在.net core中原生支持PEM格式的密钥 ，ImportRSAPrivateKey 导入私钥
	    rsa.ImportRSAPrivateKey(Convert.FromBase64String(configuration.GetSection("Jwt:Prikey").Value), out _);
            SecurityKey key2 = new RsaSecurityKey(rsa);
            var token = new JwtSecurityToken(
                issuer: configuration.GetSection("Jwt:Issuer").Value,
                audience: configuration.GetSection("Jwt:Audience").Value,
                expires: DateTime.Now.AddDays(1),
                notBefore: DateTime.Now,
                claims: claims,
                signingCredentials: new SigningCredentials(key2, SecurityAlgorithms.RsaSha256)
                );

            var jwtToken = new JwtSecurityTokenHandler().WriteToken(token);
            return Task.FromResult(jwtToken);

        }

public void ConfigureServices(IServiceCollection services)
        {
            .......................

            var configurationBuilder = new ConfigurationBuilder().AddJsonFile("appsettings.json");
            var configuration = configurationBuilder.Build();
            var rsa = RSA.Create();
            var pubkey = File.ReadAllText("Public.key").Replace("-----BEGIN RSA PUBLIC KEY-----", "").Replace("-----END RSA PUBLIC KEY-----", "").Replace("\r", "").Replace("\n", "").Replace(" ", "");
            //ImportRSAPublicKey  导入公钥
            rsa.ImportRSAPublicKey(Convert.FromBase64String(pubkey), out _);
            SecurityKey key2 = new RsaSecurityKey(rsa);

            services.AddAuthorization(options =>
            {

            }).AddAuthentication(options =>
            {
                options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
            }).AddJwtBearer(options =>
            {
                options.TokenValidationParameters = new TokenValidationParameters()
                {
                    ValidateIssuer = true,
                    ValidateAudience = true,
                    ValidateLifetime = true,
                    ValidateIssuerSigningKey = true,
                    ValidAudience = configuration.GetSection("Jwt:Audience").Value,
                    ValidIssuer = configuration.GetSection("Jwt:Issuer").Value,
                    IssuerSigningKey = key2
                };
            });

          .......................
        }
		
	public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            .......................

            app.UseAuthentication();

            app.UseAuthorization();

            .......................
        }