使用JWT和SpringBoot实现的单点登录系统

最近在自学 Java Web 开发, 听到公司 .Net 组经常说到一个词, 单点登录, 于是乎想着自己是否能用 Java 来实现一下, 于是有了下面的文章。

单点登录

　　简称为 SSO，是目前比较流行的企业业务整合的解决方案之一。SSO的定义是在多个应用系统中，用户只需要登录一次就可以访问所有相互信任的应用系统。

我们需要创建的目标

我们要创建3个独立的系统

1. 1 个认证系统: 将被部署在 localhost:8080
2. 2 个资源系统(为了简化, 我们使用相同的代码): 将分别被部署在 localhost:8180 和 localhost:8280

我要需要的环境

• JDK 1.7+
• Maven 3+

用到的技术栈

• Java
• Single Sign On (SSO)
• Json Web Token (Jwt)
• Spring Boot
• Freemarker

关于什么是 JWT, 这里推荐下面几篇文章, 讲解的比较清楚.

• 八幅漫画理解使用JSON Web Token设计单点登录系统
• JSON Web Token Tutorial with Example in Python
• Crafting your way through JSON Web Tokens

认证系统

项目结构

.
├── src
│   └─ main
│       ├── java
│       │   └── com
│       │       └── example
│       │           └── sso
│       │               ├── SsoApplication.java
│       │               └── auth
│       │                   ├── CookieUtil.java
│       │                   ├── JwtUtil.java
│       │                   └── LoginController.java
│       ├── resources
│       │   └── application.properties 
│       └── webapp
│          └── login.ftl
└── pom.xml

项目依赖

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>sso</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>sso</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-freemarker</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.6.0</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
    
</project>

CookieUtil

Jwt Token 将通过 Cookies 保存和提取

src/main/java/com/example/sso/auth/CookieUtil.java

package com.example.sso.auth;

import org.springframework.web.util.WebUtils;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class CookieUtil {
    public static void create(HttpServletResponse httpServletResponse, String name, String value, Boolean secure, Integer maxAge, String domain) {
        Cookie cookie = new Cookie(name, value);
        cookie.setSecure(secure);
        cookie.setHttpOnly(true);
        cookie.setMaxAge(maxAge);
        cookie.setPath("/");
        httpServletResponse.addCookie(cookie);
    }

    public static void clear(HttpServletResponse httpServletResponse, String name) {
        Cookie cookie = new Cookie(name, null);
        cookie.setPath("/");
        cookie.setHttpOnly(true);
        cookie.setMaxAge(0);
        httpServletResponse.addCookie(cookie);
    }

    public static String getValue(HttpServletRequest httpServletRequest, String name) {
        Cookie cookie = WebUtils.getCookie(httpServletRequest, name);
        return cookie != null ? cookie.getValue() : null;
    }
}

cookie.setSecure(secure): secure=true => 仅仅能在 HTTPS 连接中被浏览器传递到服务器端进行会话验证.
cookie.setHttpOnly(true): 使得 Javascript 脚本不能读取 cookies.
cookie.setMaxAge(maxAge): 设置 Cookies 的过期值. maxAge=0 => 立即过期, maxAge=-1 => 永不过期
cookie.setDomain(domain): Cookies 仅对设置的域名可见.
cookie.setPath("/"): Cookies 对所有路径可见.

JwtUtil

我们使用 JJWt 来生成和解析 JWT Token.

src/main/java/com/example/sso/auth/JwtUtil.java

package com.example.sso.auth;

import io.jsonwebtoken.JwtBuilder;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;

import javax.servlet.http.HttpServletRequest;
import java.util.Date;

public class JwtUtil {
    public static String generateToken(String signingKey, String subject) {
        long nowMillis = System.currentTimeMillis();
        Date now = new Date(nowMillis);

        JwtBuilder builder = Jwts.builder()
                .setSubject(subject)
                .setIssuedAt(now)
                .signWith(SignatureAlgorithm.HS256, signingKey);

        return builder.compact();
    }

    public static String getSubject(HttpServletRequest httpServletRequest, String jwtTokenCookieName, String signingKey) {
        String token = CookieUtil.getValue(httpServletRequest, jwtTokenCookieName);

        if (token == null) return null;
        return Jwts.parser().setSigningKey(signingKey).parseClaimsJws(token).getBody().getSubject();
    }
}

LoginController

src/main/java/com/example/sso/auth/LoginController.java

package com.example.sso.auth;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.http.HttpServletResponse;
import java.util.HashMap;
import java.util.Map;

@Controller
public class LoginController {
    private static final String jwtTokenCookieName = "JWT-TOKEN";
    private static final String signingKey = "signingKey";
    private static final Map<String, String> credentials = new HashMap<>();

    public LoginController() {
        credentials.put("hellokoding", "hellokoding");
        credentials.put("hellosso", "hellosso");
    }

    @RequestMapping("/")
    public String home() {
        return "redirect:/login";
    }

    @RequestMapping("/login")
    public String login() {
        return "login";
    }

    @RequestMapping(value = "login", method = RequestMethod.POST)
    public String login(HttpServletResponse httpServletResponse, String username, String password, String redirect, Model model) {
        if (username == null || !credentials.containsKey(username) || !credentials.get(username).equals(password)) {
            model.addAttribute("error", "Invalid username or password!");
            return "login";
        }

        String token = JwtUtil.generateToken(signingKey, username);
        CookieUtil.create(httpServletResponse, jwtTokenCookieName, token, false, -1, "localhost");

        return "redirect:" + redirect;
    }

}

为了简化, 我们使用 Hash Map (credentials) 作为用户数据库.

视图 (View Template)

src/main/webapp/login.ftl

<!doctype html>
<html lang="en">
<head>
    <title>认证系统</title>
</head>
<body>

<form action="/login?redirect=${RequestParameters.redirect!}" method="POST">
    <h2>Login in</h2>
    <input type="text" name="username" placeholder="用户名" autofocus="true" />
    <input type="text" name="password" placeholder="密码" />
    <div>(用户名: hellokoding  密码: hellokoding)</div>
    <div style="color: red">${error!}</div>
    <br />
    <button type="submit">登 录</button>
</form>

</body>
</html>

应用配置

src/main/resources/application.properties

spring.freemarker.template-loader-path=/
spring.freemarker.suffix=.ftl

src/main/java/com/example/sso/SsoApplication.java

package com.example.sso;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.support.SpringBootServletInitializer;

@SpringBootApplication
public class SsoApplication extends SpringBootServletInitializer {

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
        return builder.sources(SsoApplication.class);
    }

    public static void main(String[] args) {
        SpringApplication.run(SsoApplication.class, args);
    }
}

启动

mvn clean spring-boot:run

---

资源系统

项目结构

.
├── pom.xml
├── src
│   └── main
│       ├── java
│       │   └── com
│       │       └── example
│       │           └── sso
│       │               ├── SsoApplication.java
│       │               └── auth
│       │                   ├── CookieUtil.java
│       │                   ├── JwtFilter.java
│       │                   ├── JwtUtil.java
│       │                   └── ResourceController.java
│       ├── resources
│       │   ├── application.properties
│       └── webapp
│           └── protected-resource.ftl
└── sso.iml

项目依赖

和认证系统 pom.xml 一致, 无须修改.

JwtFilter

JwtFilter 用来使请求强制通过 SSO. 如果 JWT Token 不存在(未认证), 则重定向到认证系统进行认证. 如果 JWT TOKEN 存在(已认证), 则从中提取出用户信息, 并通过请求.

src/main/java/com/example/sso/auth/JwtFilter.java

package com.example.sso.auth;

import org.springframework.stereotype.Component;
import org.springframework.web.filter.OncePerRequestFilter;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Component
public class JwtFilter extends OncePerRequestFilter {

    private static final String jwtTokenCookieName = "JWT-TOKEN";
    private static final String signingKey = "signingKey";

    @Override
    protected void doFilterInternal(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, FilterChain filterChain) throws ServletException, IOException {
        String username = JwtUtil.getSubject(httpServletRequest, jwtTokenCookieName, signingKey);
        if (username == null) {
            String authService = this.getFilterConfig().getInitParameter("services.auth");
            httpServletResponse.sendRedirect(authService + "?redirect=" + httpServletRequest.getRequestURL());
        } else {
            httpServletRequest.setAttribute("username", username);
            filterChain.doFilter(httpServletRequest, httpServletResponse);
        }
    }
}

ResourceController

package com.example.sso.auth;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletResponse;

@Controller
public class ResourceController {
    private static final String jwtTokenCookieName = "JWT-TOKEN";

    @RequestMapping("/")
    public String home() {
        return "redirect:/protected-resource";
    }

    @RequestMapping("/protected-resource")
    public String protectedResource() {
        return "protected-resource";
    }

    @RequestMapping("/logout")
    public String logout(HttpServletResponse httpServletResponse) {
        CookieUtil.clear(httpServletResponse, jwtTokenCookieName);
        return "redirect:/";
    }
}

视图 (View Template)

src/main/webapp/protected-resource.ftl

<!doctype html>
<html lang="en">
<head>
    <title>资源系统</title>
</head>
<body>
    <h2>你好, ${Request.username!}</h2>
    <a href="/logout">登 出</a>
</body>
</html>

应用配置

src/main/resources/application.properties

spring.freemarker.template-loader-path=/
spring.freemarker.suffix=.ftl

services.auth=http://localhost:8080/login

src/main/java/com/example/sso/SsoApplication.java

package com.example.sso;

import com.example.sso.auth.JwtFilter;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.support.SpringBootServletInitializer;
import org.springframework.context.annotation.Bean;

import java.util.Collections;

@SpringBootApplication
public class SsoApplication extends SpringBootServletInitializer {

    @Value("${services.auth}")
    private String authService;

    @Bean
    public FilterRegistrationBean jwtFilter() {
        final FilterRegistrationBean registrationBean = new FilterRegistrationBean();
        registrationBean.setFilter(new JwtFilter());
        registrationBean.setInitParameters(Collections.singletonMap("services.auth", authService));
        registrationBean.addUrlPatterns("/protected-resource");

        return registrationBean;
    }

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
        return builder.sources(SsoApplication.class);
    }

    public static void main(String[] args) {
        SpringApplication.run(SsoApplication.class, args);
    }
}

启动

启动资源系统 1

mvn clean spring-boot:run -Dserver.port=8180

启动资源系统 2

mvn clean spring-boot:run -Dserver.port=8280

然后大家可以访问 http://localhost:8180 去看看效果哈~~~

主要参考文章: Single Sign On (SSO), Scalable Authentication Example with JSON Web Token (JWT) and Spring Boot