Spring Security认证流程分析

我自己的思路

先分别实现 userdetailsService，userDetails，passwordEncoder三个接口，

然后就是写登录逻辑 本文章用的是继承UsernamePasswordAuthenticationFilter这个接口 因为这个框架默认登录逻辑是在这里面的，里面的核心就是通过

这里这个接口可以不用写过滤器里，可以直接写在serviceImpl里面的登录逻辑里面，

关键是要AuthenticationManager()这个注入到spring容器里

Authentication authenticationToken = new UsernamePasswordAuthenticationToken(loginVo.getUsername(), loginVo.getPassword());

AuthenticationManager().authenticate(authenticationToken);

登录逻辑写完后，需要写个解析token的过滤器，作用是看用户是否登录，访问其它接口的时候

所以它是在usernamepasswordFilter 之前的

然后把这个加入配置类，进行配置

1.认证过程

1.1、创建spring-security模块

在common模块下创建spring-security公共模块，创建方式如：service-util模块

1.2、添加依赖

修改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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
​
    <parent>
        <groupId>com.atguigu</groupId>
        <artifactId>common</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>
​
    <artifactId>spring-security</artifactId>
    
    <dependencies>
        <dependency>
            <groupId>com.atguigu</groupId>
            <artifactId>common-util</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <!-- Spring Security依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <scope>provided </scope>
        </dependency>
    </dependencies>
​
</project>

说明：依赖包（spring-boot-starter-security）导入后，Spring Security就默认提供了许多功能将整个应用给保护了起来：

1、要求经过身份验证的用户才能与应用程序进行交互

2、创建好了默认登录表单

3、生成用户名为user的随机密码并打印在控制台上

1.3、添加配置类

package com.atguigu.security.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;

@Configuration
@EnableWebSecurity //@EnableWebSecurity是开启SpringSecurity的默认行为
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

}

2、用户认证

用户认证流程：

2.1、用户认证核心组件

我们需要通过 SecurityContext 来获取Authentication，SecurityContext就是我们的上下文对象！这个上下文对象则是交由 SecurityContextHolder 进行管理，你可以在程序任何地方使用它：

Authentication authentication = SecurityContextHolder.getContext().getAuthentication();

现在我们已经知道了Spring Security中三个核心组件：

1、Authentication：存储了认证信息，代表当前登录用户

2、SeucirtyContext：上下文对象，用来获取Authentication

3、SecurityContextHolder：上下文管理对象，用来在程序任何地方获取SecurityContext

Authentication中是什么信息呢：

1、Principal：用户信息，没有认证时一般是用户名，认证后一般是用户对象

2、Credentials：用户凭证，一般是密码

3、Authorities：用户权限

2.2：代码实现思路：

首先说前三步是对这个地方做更改，因为它的默认行为，不符合开发要求

第一步：

实现UserDetailsService这个接口 里面有loadUserByUsername(String username)这个方法，为什么要重写，因为默认机制是在内存中查，而我们要在数据库中查

 @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {

        SysUser sysUser = sysUserMapper.selectOne(new LambdaQueryWrapper<SysUser>().eq(SysUser::getUsername, username));
        if(sysUser==null) throw new GuiguException(ResultCodeEnum.DATA_ERROR);
        if(sysUser.getStatus()==0) throw new GuiguException(ResultCodeEnum.SERVICE_ERROR);
        List<String> userPermsList = sysMenuService.findUserPermsByUserId(sysUser.getId());
        List<SimpleGrantedAuthority> authorities = new ArrayList<>();
        for (String perm : userPermsList) {
            authorities.add(new SimpleGrantedAuthority(perm.trim()));
        }
        return new CustomUser(sysUser, authorities);
    }

第二步

实现UserDetails这个接口 ，按需要重写里面的方法，因为它的属性不一定符合我们的要求

第三步

重写PasswordEncoder这个类，它的功能是对密码进行加密和校验，我用的是MD5进行加密

MD5工具类

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加密出错！！+" + e);
        }
    }


}

public class CustomMd5PasswordEncoder implements PasswordEncoder {
    public String encode(CharSequence rawPassword) {
        return MD5.encrypt(rawPassword.toString());
    }

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

第四步

对这个部分进行修改，因为我们要让账号密码走我们自己写的登录controller

继承UsernamePasswordAuthenticationFilter 这个类，重写里面的登录逻辑，和认证成功，认证失败方法

import com.atguigu.common.jwt.JwtHelper;
import com.atguigu.common.result.Result;
import com.atguigu.common.result.ResultCodeEnum;
import com.atguigu.common.util.ResponseUtil;
import com.atguigu.security.custom.CustomUser;
import com.atguigu.vo.system.LoginVo;
import com.fasterxml.jackson.databind.ObjectMapper;
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.HashMap;
import java.util.Map;

/**
 * <p>
 * 登录过滤器，继承UsernamePasswordAuthenticationFilter，对用户名密码进行登录校验
 * </p>
 */
public class TokenLoginFilter extends UsernamePasswordAuthenticationFilter {

    public TokenLoginFilter(AuthenticationManager authenticationManager) {
        this.setAuthenticationManager(authenticationManager);
        this.setPostOnly(false);
        //指定登录接口及提交方式，可以指定任意路径
        this.setRequiresAuthenticationRequestMatcher(new AntPathRequestMatcher("/admin/system/index/login","POST"));
    }

    /**
     * 登录认证
     * @param req
     * @param res
     * @return
     * @throws AuthenticationException
     */
    @Override
    public Authentication attemptAuthentication(HttpServletRequest req, HttpServletResponse res)
            throws AuthenticationException {
        try {
            LoginVo loginVo = new ObjectMapper().readValue(req.getInputStream(), LoginVo.class);

            Authentication authenticationToken = new UsernamePasswordAuthenticationToken(loginVo.getUsername(), loginVo.getPassword());
            return this.getAuthenticationManager().authenticate(authenticationToken);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

    }

    /**
     * 登录成功
     * @param request
     * @param response
     * @param chain
     * @param auth
     * @throws IOException
     * @throws ServletException
     */
    @Override
    protected void successfulAuthentication(HttpServletRequest request, HttpServletResponse response, FilterChain chain,
                                            Authentication auth) throws IOException, ServletException {
        CustomUser customUser = (CustomUser) auth.getPrincipal();
        String token = JwtHelper.createToken(customUser.getSysUser().getId(), customUser.getSysUser().getUsername());

        Map<String, Object> map = new HashMap<>();
        map.put("token", token);
        ResponseUtil.out(response, Result.ok(map));
    }

    /**
     * 登录失败
     * @param request
     * @param response
     * @param e
     * @throws IOException
     * @throws ServletException
     */
    @Override
    protected void unsuccessfulAuthentication(HttpServletRequest request, HttpServletResponse response,
                                              AuthenticationException e) throws IOException, ServletException {

        if(e.getCause() instanceof RuntimeException) {
            ResponseUtil.out(response, Result.build(null, 204, e.getMessage()));
        } else {
            ResponseUtil.out(response, Result.build(null, ResultCodeEnum.LOGIN_MOBLE_ERROR));
        }
    }
}

第五步 写一个过滤器 这个过滤器的目的是访问其它接口（不包含登录接口）看是否有权限登录

public class TokenAuthenticationFilter extends OncePerRequestFilter {

    private RedisTemplate redisTemplate;

    public TokenAuthenticationFilter(RedisTemplate redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        logger.info("uri:"+request.getRequestURI());
        //如果是登录接口，直接放行
        if("/admin/system/index/login".equals(request.getRequestURI())) {
            chain.doFilter(request, response);
            return;
        }

        UsernamePasswordAuthenticationToken authentication = getAuthentication(request);
        if(null != authentication) {
            SecurityContextHolder.getContext().setAuthentication(authentication);
            chain.doFilter(request, response);
        } else {
            ResponseUtil.out(response, Result.build(null, ResultCodeEnum.PERMISSION));
        }
    }

    private UsernamePasswordAuthenticationToken getAuthentication(HttpServletRequest request) {
        // token置于header里
        String token = request.getHeader("token");
        logger.info("token:"+token);
        if (!StringUtils.isEmpty(token)) {
            String username = JwtHelper.getUsername(token);
            logger.info("username:"+username);
            if (!StringUtils.isEmpty(username)) {
                String authoritiesString = (String) redisTemplate.opsForValue().get(username);
                List<Map> mapList = JSON.parseArray(authoritiesString, Map.class);
                List<SimpleGrantedAuthority> authorities = new ArrayList<>();
                for (Map map : mapList) {
                    authorities.add(new SimpleGrantedAuthority((String)map.get("authority")));
                }
                return new UsernamePasswordAuthenticationToken(username, null, authorities);
            } else {
                return new UsernamePasswordAuthenticationToken(username, null, new ArrayList<>());
            }
        }
        return null;
    }

}

最后 配置用户认证

import com.atguigu.custom.CustomMd5PasswordEncoder;
import com.atguigu.fillter.TokenAuthenticationFilter;
import com.atguigu.fillter.TokenLoginFilter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.security.authentication.AuthenticationManager;
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.config.http.SessionCreationPolicy;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;

import javax.annotation.Resource;


@Configuration
@EnableWebSecurity //@EnableWebSecurity是开启SpringSecurity的默认行为
@EnableGlobalMethodSecurity(prePostEnabled = true)//开启注解功能，默认禁用注解
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Resource
    private UserDetailsService userDetailsService;

    @Resource
    private CustomMd5PasswordEncoder customMd5PasswordEncoder;

    @Resource
    private RedisTemplate redisTemplate;

    @Bean
    @Override
    protected AuthenticationManager authenticationManager() throws Exception {
        return super.authenticationManager();
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        // 这是配置的关键，决定哪些接口开启防护，哪些接口绕过防护
        http
                //关闭csrf
                .csrf().disable()
                // 开启跨域以便前端调用接口
                .cors().and()
                .authorizeRequests()
                // 指定某些接口不需要通过验证即可访问。登陆接口肯定是不需要认证的
                //.antMatchers("/admin/system/index/login").permitAll()
                // 这里意思是其它所有接口需要认证才能访问
                .anyRequest().authenticated()
                .and()
                //TokenAuthenticationFilter放到UsernamePasswordAuthenticationFilter的前面，这样做就是为了除了登录的时候去查询数据库外，其他时候都用token进行认证。
                .addFilterBefore(new TokenAuthenticationFilter(redisTemplate), UsernamePasswordAuthenticationFilter.class)
                .addFilter(new TokenLoginFilter(authenticationManager(), redisTemplate));

        //禁用session
        http.sessionManagement().sessionCreationPolicy(SessionCreationPolicy.STATELESS);
    }

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        // 指定UserDetailService和加密器
        auth.userDetailsService(userDetailsService).passwordEncoder(customMd5PasswordEncoder);
    }

    /**
     * 配置哪些请求不拦截
     * 排除swagger相关请求
     * @param web
     * @throws Exception
     */
    @Override
    public void configure(WebSecurity web) throws Exception {
        web.ignoring().antMatchers("/favicon.ico","/swagger-resources/**", "/webjars/**", "/v2/**", "/swagger-ui.html/**", "/doc.html");
    }
}