+----------+     登錄請(qǐng)求      +----------+
|          | -------------->  |          |
| 客戶端   |                   | 服務(wù)器   |
|          | <--------------  |          |
+----------+   返回JWT令牌     +----------+
       |                                 |
       |   攜帶JWT令牌的請(qǐng)求               |
       | ----------------------------->  |
       |                                 |
       | <-----------------------------  |
       |        處理后的響應(yīng)               |
       v                                 v

{
  "alg": "HS256",
  "typ": "JWT"
}

{
  "sub": "1234567890",
  "name": "John Doe",
  "role": "admin",
  "exp": 1678900000
}

PlainText
HMACSHA256(
  base64UrlEncode(header) + "." +
  base64UrlEncode(payload),
  secretKey
)

Install-Package System.IdentityModel.Tokens.Jwt
Install-Package Microsoft.AspNetCore.
Authentication.JwtBearer

Program.cs 
using Microsoft.AspNetCore.Authentication.
JwtBearer;
using Microsoft.IdentityModel.Tokens;
using System.Text;
?
var builder = WebApplication.CreateBuilder(args);
?
// 添加JWT認(rèn)證服務(wù)
builder.Services.AddAuthentication
(JwtBearerDefaults.AuthenticationScheme)
    .AddJwtBearer(options =>
    {
        options.TokenValidationParameters = new 
        TokenValidationParameters
        {
            ValidateIssuer = true, // 驗(yàn)證頒發(fā)者
            ValidateAudience = true, // 驗(yàn)證受眾
            ValidateLifetime = true, // 驗(yàn)證過期時(shí)
            間
            ValidateIssuerSigningKey = true, // 驗(yàn)
            證簽名密鑰
            ValidIssuer = builder.Configuration
            ["Jwt:Issuer"], // 頒發(fā)者
            ValidAudience = builder.Configuration
            ["Jwt:Audience"], // 受眾
            IssuerSigningKey = new 
            SymmetricSecurityKey(Encoding.UTF8.
            GetBytes(builder.Configuration
            ["Jwt:SecretKey"])) // 簽名密鑰
        };
    });
?
// 添加授權(quán)服務(wù)
builder.Services.AddAuthorization();
?
var app = builder.Build();
?
// 使用認(rèn)證和授權(quán)中間件
app.UseAuthentication();
app.UseAuthorization();
?
app.MapControllers();
app.Run();

appsettings.json
應(yīng)用
{
  "Jwt": {
    "Issuer": "YourIssuer",
    "Audience": "YourAudience",
    "SecretKey": 
    "YourSecretKeyHereShouldBeLongEnough"
  },
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*"
}

AuthController.cs
?
using Microsoft.AspNetCore.Mvc;
using Microsoft.IdentityModel.Tokens;
using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using System.Text;
?
[ApiController]
[Route("api/[controller]")]
public class AuthController : ControllerBase
{
    private readonly IConfiguration 
    _configuration;
?
    public AuthController(IConfiguration 
    configuration)
    {
        _configuration = configuration;
    }
?
    [HttpPost("login")]
    public IActionResult Login([FromBody] 
    LoginRequest request)
    {
        // 驗(yàn)證用戶憑據(jù)（實(shí)際應(yīng)用中應(yīng)查詢數(shù)據(jù)庫(kù)）
        if (request.Username == "admin" && 
        request.Password == "password")
        {
            // 創(chuàng)建用戶聲明
            var claims = new[]
            {
                new Claim(ClaimTypes.Name, 
                request.Username),
                new Claim(ClaimTypes.Role, 
                "admin"),
                new Claim(JwtRegisteredClaimNames.
                Sub, "1234567890"),
                new Claim(JwtRegisteredClaimNames.
                Jti, Guid.NewGuid().ToString())
            };
?
            // 生成對(duì)稱安全密鑰
            var key = new SymmetricSecurityKey
            (Encoding.UTF8.GetBytes(_configuration
            ["Jwt:SecretKey"]));
?
            // 生成簽名憑據(jù)
            var creds = new SigningCredentials
            (key, SecurityAlgorithms.HmacSha256);
?
            // 創(chuàng)建JWT令牌
            var token = new JwtSecurityToken(
                issuer: _configuration
                ["Jwt:Issuer"],
                audience: _configuration
                ["Jwt:Audience"],
                claims: claims,
                expires: DateTime.Now.AddMinutes
                (30),
                signingCredentials: creds);
?
            // 返回JWT令牌
            return Ok(new
            {
                token = new 
                JwtSecurityTokenHandler().
                WriteToken(token),
                expiration = token.ValidTo
            });
        }
?
        return Unauthorized();
    }
}
?
public class LoginRequest
{
    public string Username { get; set; }
    public string Password { get; set; }
}

ValuesController.cs
?
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
?
[ApiController]
[Route("api/[controller]")]
[Authorize]
public class ValuesController : ControllerBase
{
    [HttpGet]
    public IActionResult Get()
    {
        return Ok(new string[] { "value1", 
        "value2" });
    }
?
    [HttpGet("{id}")]
    [Authorize(Roles = "admin")]
    public IActionResult Get(int id)
    {
        return Ok($"value {id}");
    }
}