1. Introduction to Spring Security

1.1 Framework Overview

Spring is a highly popular and successful Java application development framework. Spring Security, built upon the Spring framework, provides a comprehensive solution for web application security. Generally, web application security includes two parts: user authentication and user authorization.

• User Authentication: Verifies whether a user is a legitimate entity in the system, i.e., whether the user can access the system. User authentication typically requires the user to provide a username and password. The system validates the username and password to complete the authentication process.
• User Authorization: Verifies whether a user has permission to perform a specific operation. Different users have different permissions within a system. For example, for a file, some users may only be able to read it, while others can modify it. Generally, systems assign different roles to different users, and each role corresponds to a set of permissions.

Spring Security essentially uses filters to filter multiple request paths:

• For Session-based authentication, Spring Security parses the session ID from the cookie, finds the session information stored on the server, and determines if the current user meets the request requirements.
• For Token-based authentication, Spring Security parses the token and adds the current request to the permission information managed by Spring Security.

In both session and token approaches, the handling of storing and retrieving values is delegated to Spring Security.

1.2 Authentication and Authorization Implementation Approach

Given a systeem with numerous modules, each requiring authorization and authentication, we opt for a token-based approach for authorization and authentication. The user authenticates with a username and password. Upon successful authentication, the system retrieves the current user's role-based permission list, stores it in Redis cache with the username as the key and the permission list as the value, generates a token based on the username-related information, and returns it. The browser stores the token in a cookie. Every API call includes the token in the request header. Spring Security parses the header to retrieve the token, extracts the username from the token, and then retrieves the permission list from Redis based on the username. This allows Spring Security to determine if the current request has the necessary permissions to access the resource.

2. Integrating Spring Security

2.1 Create Spring Security Module

Create a new module named spring_security under the common module.

2.2 Add Dependencies to spring_security

<dependencies>
    <dependency>
        <groupId>com.atguigu</groupId>
        <artifactId>common_utils</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </dependency>
    <!-- Spring Security dependency -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-security</artifactId>
    </dependency>

    <dependency>
        <groupId>io.jsonwebtoken</groupId>
        <artifactId>jjwt</artifactId>
    </dependency>
</dependencies>

2.3 Code Structure Explanation

Note: The class names above are arbitrary (some specific code needs to inherit Spring Security interfaces).

Detailed Code Implementation (Pay Attention to Correct Imports)

TokenWebSecurityConfig - Core Configuration Class

package com.atguigu.serurity.config;

import com.atguigu.serurity.filter.TokenAuthenticationFilter;
import com.atguigu.serurity.filter.TokenLoginFilter;
import com.atguigu.serurity.security.DefaultPasswordEncoder;
import com.atguigu.serurity.security.TokenLogoutHandler;
import com.atguigu.serurity.security.TokenManager;
import com.atguigu.serurity.security.UnauthorizedEntryPoint;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.builders.WebSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.core.userdetails.UserDetailsService;

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
public class TokenWebSecurityConfig extends WebSecurityConfigurerAdapter {

    private UserDetailsService userDetailsService;
    private TokenManager tokenManager;
    private DefaultPasswordEncoder defaultPasswordEncoder;
    private RedisTemplate redisTemplate;

    @Autowired
    public TokenWebSecurityConfig(UserDetailsService userDetailsService, DefaultPasswordEncoder defaultPasswordEncoder,
                                  TokenManager tokenManager, RedisTemplate redisTemplate) {
        this.userDetailsService = userDetailsService;
        this.defaultPasswordEncoder = defaultPasswordEncoder;
        this.tokenManager = tokenManager;
        this.redisTemplate = redisTemplate;
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.exceptionHandling()
                .authenticationEntryPoint(new UnauthorizedEntryPoint())
                .and().csrf().disable()
                .authorizeRequests()
                .anyRequest().authenticated()
                .and().logout().logoutUrl("/admin/acl/index/logout")
                .addLogoutHandler(new TokenLogoutHandler(tokenManager, redisTemplate)).and()
                .addFilter(new TokenLoginFilter(authenticationManager(), tokenManager, redisTemplate))
                .addFilter(new TokenAuthenticationFilter(authenticationManager(), tokenManager, redisTemplate)).httpBasic();
    }

    @Override
    public void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(userDetailsService).passwordEncoder(defaultPasswordEncoder);
    }

    @Override
    public void configure(WebSecurity web) throws Exception {
        web.ignoring().antMatchers("/api/**",
                "/swagger-resources/**", "/webjars/**", "/v2/**", "/swagger-ui.html/**");
    }
}

Entity Classes: SecurityUser and User

package com.atguigu.serurity.entity;

import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.util.StringUtils;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

@Data
@Slf4j
public class SecurityUser implements UserDetails {

    private transient User currentUserInfo;
    private List<String> permissionValueList;

    public SecurityUser() {
    }

    public SecurityUser(User user) {
        if (user != null) {
            this.currentUserInfo = user;
        }
    }

    @Override
    public Collection<? extends GrantedAuthority> getAuthorities() {
        Collection<GrantedAuthority> authorities = new ArrayList<>();
        for (String permissionValue : permissionValueList) {
            if (StringUtils.isEmpty(permissionValue)) continue;
            SimpleGrantedAuthority authority = new SimpleGrantedAuthority(permissionValue);
            authorities.add(authority);
        }
        return authorities;
    }

    @Override
    public String getPassword() {
        return currentUserInfo.getPassword();
    }

    @Override
    public String getUsername() {
        return currentUserInfo.getUsername();
    }

    @Override
    public boolean isAccountNonExpired() {
        return true;
    }

    @Override
    public boolean isAccountNonLocked() {
        return true;
    }

    @Override
    public boolean isCredentialsNonExpired() {
        return true;
    }

    @Override
    public boolean isEnabled() {
        return true;
    }
}

package com.atguigu.serurity.entity;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;

import java.io.Serializable;

@Data
@ApiModel(description = "User Entity")
public class User implements Serializable {

    private static final long serialVersionUID = 1L;

    @ApiModelProperty(value = "WeChat openid")
    private String username;

    @ApiModelProperty(value = "Password")
    private String password;

    @ApiModelProperty(value = "Nickname")
    private String nickName;

    @ApiModelProperty(value = "User avatar")
    private String salt;

    @ApiModelProperty(value = "User signature")
    private String token;
}

The above classes follow the required structure for Spring Security.

TokenAuthenticationFilter - Authorization Filter

package com.atguigu.serurity.filter;

import com.atguigu.commonutils.R;
import com.atguigu.commonutils.ResponseUtil;
import com.atguigu.serurity.security.TokenManager;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.web.authentication.www.BasicAuthenticationFilter;
import org.springframework.util.StringUtils;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

public class TokenAuthenticationFilter extends BasicAuthenticationFilter {
    private TokenManager tokenManager;
    private RedisTemplate redisTemplate;

    public TokenAuthenticationFilter(AuthenticationManager authManager, TokenManager tokenManager, RedisTemplate redisTemplate) {
        super(authManager);
        this.tokenManager = tokenManager;
        this.redisTemplate = redisTemplate;
    }

    @Override
    protected void doFilterInternal(HttpServletRequest req, HttpServletResponse res, FilterChain chain)
            throws IOException, ServletException {
        logger.info("=================" + req.getRequestURI());
        if (req.getRequestURI().indexOf("admin") == -1) {
            chain.doFilter(req, res);
            return;
        }

        UsernamePasswordAuthenticationToken authentication = null;
        try {
            authentication = getAuthentication(req);
        } catch (Exception e) {
            ResponseUtil.out(res, R.error());
        }

        if (authentication != null) {
            SecurityContextHolder.getContext().setAuthentication(authentication);
        } else {
            ResponseUtil.out(res, R.error());
        }
        chain.doFilter(req, res);
    }

    private UsernamePasswordAuthenticationToken getAuthentication(HttpServletRequest request) {
        String token = request.getHeader("token");
        if (token != null && !"".equals(token.trim())) {
            String userName = tokenManager.getUserFromToken(token);

            List<String> permissionValueList = (List<String>) redisTemplate.opsForValue().get(userName);
            Collection<GrantedAuthority> authorities = new ArrayList<>();
            for (String permissionValue : permissionValueList) {
                if (StringUtils.isEmpty(permissionValue)) continue;
                SimpleGrantedAuthority authority = new SimpleGrantedAuthority(permissionValue);
                authorities.add(authority);
            }

            if (!StringUtils.isEmpty(userName)) {
                return new UsernamePasswordAuthenticationToken(userName, token, authorities);
            }
            return null;
        }
        return null;
    }
}

TokenLoginFilter - Authentication Filter (Login)

package com.atguigu.serurity.filter;

import com.atguigu.commonutils.R;
import com.atguigu.commonutils.ResponseUtil;
import com.atguigu.serurity.entity.SecurityUser;
import com.atguigu.serurity.entity.User;
import com.atguigu.serurity.security.TokenManager;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;
import org.springframework.security.web.util.matcher.AntPathRequestMatcher;

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

public class TokenLoginFilter extends UsernamePasswordAuthenticationFilter {

    private AuthenticationManager authenticationManager;
    private TokenManager tokenManager;
    private RedisTemplate redisTemplate;

    public TokenLoginFilter(AuthenticationManager authenticationManager, TokenManager tokenManager, RedisTemplate redisTemplate) {
        this.authenticationManager = authenticationManager;
        this.tokenManager = tokenManager;
        this.redisTemplate = redisTemplate;
        this.setPostOnly(false);
        this.setRequiresAuthenticationRequestMatcher(new AntPathRequestMatcher("/admin/acl/login", "POST"));
    }

    @Override
    public Authentication attemptAuthentication(HttpServletRequest req, HttpServletResponse res)
            throws AuthenticationException {
        try {
            User user = new ObjectMapper().readValue(req.getInputStream(), User.class);
            return authenticationManager.authenticate(new UsernamePasswordAuthenticationToken(user.getUsername(), user.getPassword(), new ArrayList<>()));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    protected void successfulAuthentication(HttpServletRequest req, HttpServletResponse res, FilterChain chain,
                                            Authentication auth) throws IOException, ServletException {
        SecurityUser user = (SecurityUser) auth.getPrincipal();
        String token = tokenManager.createToken(user.getCurrentUserInfo().getUsername());
        redisTemplate.opsForValue().set(user.getCurrentUserInfo().getUsername(), user.getPermissionValueList());

        ResponseUtil.out(res, R.ok().data("token", token));
    }

    @Override
    protected void unsuccessfulAuthentication(HttpServletRequest request, HttpServletResponse response,
                                              AuthenticationException e) throws IOException, ServletException {
        ResponseUtil.out(response, R.error());
    }
}

Utility Classes in security Package and common Package

DefaultPasswordEncoder

package com.atguigu.serurity.security;

import com.atguigu.commonutils.MD5;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.stereotype.Component;

@Component
public class DefaultPasswordEncoder implements PasswordEncoder {

    public DefaultPasswordEncoder() {
        this(-1);
    }

    public DefaultPasswordEncoder(int strength) {
    }

    public String encode(CharSequence rawPassword) {
        return MD5.encrypt(rawPassword.toString());
    }

    public boolean matches(CharSequence rawPassword, String encodedPassword) {
        return encodedPassword.equals(MD5.encrypt(rawPassword.toString()));
    }
}

TokenLogoutHandler

package com.atguigu.serurity.security;

import com.atguigu.commonutils.R;
import com.atguigu.commonutils.ResponseUtil;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.security.core.Authentication;
import org.springframework.security.web.authentication.logout.LogoutHandler;

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

public class TokenLogoutHandler implements LogoutHandler {

    private TokenManager tokenManager;
    private RedisTemplate redisTemplate;

    public TokenLogoutHandler(TokenManager tokenManager, RedisTemplate redisTemplate) {
        this.tokenManager = tokenManager;
        this.redisTemplate = redisTemplate;
    }

    @Override
    public void logout(HttpServletRequest request, HttpServletResponse response, Authentication authentication) {
        String token = request.getHeader("token");
        if (token != null) {
            tokenManager.removeToken(token);

            // Clear the permission data in the cache for the current user
            String userName = tokenManager.getUserFromToken(token);
            redisTemplate.delete(userName);
        }
        ResponseUtil.out(response, R.ok());
    }
}

TokenManager

package com.atguigu.serurity.security;

import io.jsonwebtoken.CompressionCodecs;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import org.springframework.stereotype.Component;

import java.util.Date;

@Component
public class TokenManager {

    private long tokenExpiration = 24 * 60 * 60 * 1000;
    private String tokenSignKey = "123456";

    public String createToken(String username) {
        String token = Jwts.builder().setSubject(username)
                .setExpiration(new Date(System.currentTimeMillis() + tokenExpiration))
                .signWith(SignatureAlgorithm.HS512, tokenSignKey).compressWith(CompressionCodecs.GZIP).compact();
        return token;
    }

    public String getUserFromToken(String token) {
        String user = Jwts.parser().setSigningKey(tokenSignKey).parseClaimsJws(token).getBody().getSubject();
        return user;
    }

    public void removeToken(String token) {
        // JWT token doesn't need to be deleted; client can discard it.
    }
}

UnauthorizedEntryPoint

package com.atguigu.serurity.security;

import com.atguigu.commonutils.R;
import com.atguigu.commonutils.ResponseUtil;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.AuthenticationEntryPoint;

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

public class UnauthorizedEntryPoint implements AuthenticationEntryPoint {

    @Override
    public void commence(HttpServletRequest request, HttpServletResponse response,
                         AuthenticationException authException) throws IOException, ServletException {
        ResponseUtil.out(response, R.error());
    }
}

MD5 Utility (common package)

package com.atguigu.commonutils;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public final class MD5 {

    public static String encrypt(String strSrc) {
        try {
            char hexChars[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8',
                    '9', 'a', 'b', 'c', 'd', 'e', 'f' };
            byte[] bytes = strSrc.getBytes();
            MessageDigest md = MessageDigest.getInstance("MD5");
            md.update(bytes);
            bytes = md.digest();
            int j = bytes.length;
            char[] chars = new char[j * 2];
            int k = 0;
            for (int i = 0; i < bytes.length; i++) {
                byte b = bytes[i];
                chars[k++] = hexChars[b >>> 4 & 0xf];
                chars[k++] = hexChars[b & 0xf];
            }
            return new String(chars);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
            throw new RuntimeException("MD5 encryption error: " + e);
        }
    }

    public static void main(String[] args) {
        System.out.println(MD5.encrypt("111111"));
    }
}

ResponseUtil

package com.atguigu.commonutils;

import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class ResponseUtil {

    public static void out(HttpServletResponse response, R r) {
        ObjectMapper mapper = new ObjectMapper();
        response.setStatus(HttpStatus.OK.value());
        response.setContentType(MediaType.APPLICATION_JSON_UTF8_VALUE);
        try {
            mapper.writeValue(response.getWriter(), r);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

JwtUtils (Backup Utility)

package com.atguigu.commonutils;

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jws;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import org.springframework.util.StringUtils;

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

public class JwtUtils {

    public static final long EXPIRE = 1000 * 60 * 60 * 24;
    public static final String APP_SECRET = "ukc8BDbRigUDaY6pZFfWus2jZWLPHO";

    public static String getJwtToken(String id, String nickname){
        String JwtToken = Jwts.builder()
                .setHeaderParam("typ", "JWT")
                .setHeaderParam("alg", "HS256")
                .setSubject("guli-user")
                .setIssuedAt(new Date())
                .setExpiration(new Date(System.currentTimeMillis() + EXPIRE))
                .claim("id", id)
                .claim("nickname", nickname)
                .signWith(SignatureAlgorithm.HS256, APP_SECRET)
                .compact();
        return JwtToken;
    }

    public static boolean checkToken(String jwtToken) {
        if(StringUtils.isEmpty(jwtToken)) return false;
        try {
            Jwts.parser().setSigningKey(APP_SECRET).parseClaimsJws(jwtToken);
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
        return true;
    }

    public static boolean checkToken(HttpServletRequest request) {
        try {
            String jwtToken = request.getHeader("token");
            if(StringUtils.isEmpty(jwtToken)) return false;
            Jwts.parser().setSigningKey(APP_SECRET).parseClaimsJws(jwtToken);
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
        return true;
    }

    public static String getMemberIdByJwtToken(HttpServletRequest request) {
        String jwtToken = request.getHeader("token");
        if(StringUtils.isEmpty(jwtToken)) return "";
        Jws<Claims> claimsJws = Jwts.parser().setSigningKey(APP_SECRET).parseClaimsJws(jwtToken);
        Claims claims = claimsJws.getBody();
        return (String)claims.get("id");
    }
}

2.4 Implement Custom User Details Service

Create a class that implements the UserDetailsService interface to execute custom business logic.

Create Custom User Query Class

Create this class in the service_acl module since other modules won't use it.

UserDetailsServiceImpl

package com.atguigu.aclservice.service.impl;

import com.atguigu.aclservice.entity.User;
import com.atguigu.aclservice.service.PermissionService;
import com.atguigu.aclservice.service.UserService;
import com.atguigu.serurity.entity.SecurityUser;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.core.userdetails.UsernameNotFoundException;
import org.springframework.stereotype.Service;

import java.util.List;

@Service("userDetailsService")
public class UserDetailsServiceImpl implements UserDetailsService {

    @Autowired
    private UserService userService;

    @Autowired
    private PermissionService permissionService;

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        // Retrieve user from database
        User user = userService.selectByUsername(username);

        // Return UserDetails implementation
        com.atguigu.serurity.entity.User curUser = new com.atguigu.serurity.entity.User();
        BeanUtils.copyProperties(user, curUser);

        List<String> authorities = permissionService.selectPermissionValueByUserId(user.getId());
        SecurityUser securityUser = new SecurityUser(curUser);
        securityUser.setPermissionValueList(authorities);
        return securityUser;
    }
}

3. Front-End Integration

(Details omitted)

4. Spring Security Execution Flow (Debug)

(Detailed debug steps omitted for brevity.)