1 Kaptcha 验证码

1.1 引言

为防止验证系统被暴力破解，很多系统都增加了验证码效验，比较常见的就是图片二维码，业内比较安全的是短信验证码，当然还有一些拼图验证码，加入人工智能的二维码等等，这次就是前后端分离的图片二维码登录方案。

基于验证码的轮子还是挺多的，就以 Kaptcha 这个项目为例，通过springboot项目集成Kaptcha来实现验证码生成和登录方案。

1.2 Kaptcha

Kaptcha 是一个基于SimpleCaptcha的验证码开源项目

1.2.1 pom.xml

<!--Kaptcha是一个基于SimpleCaptcha的验证码开源项目-->
<dependency>
  <groupId>com.github.penggle</groupId>
  <artifactId>kaptcha</artifactId>
  <version>2.3.2</version>
</dependency>

<!-- 其他依赖 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<!-- redis依赖commons-pool 这个依赖一定要添加 -->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-pool2</artifactId>
</dependency>

1.2.2 配置类

1.2.2.1 Redis配置类RedisConfig

@Configuration
public class RedisConfig {
    @Bean
    public RedisTemplate<String, Object> redisTemplate(LettuceConnectionFactory redisConnectionFactory){
        RedisTemplate<String, Object> redisTemplate = new RedisTemplate<String, Object>();
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());
        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        redisTemplate.setHashValueSerializer(new GenericJackson2JsonRedisSerializer());
        redisTemplate.setConnectionFactory(redisConnectionFactory);
        return redisTemplate;
    }
}

1.2.2.2 验证码配置类KaptchaConfig

@Configuration
public class KaptchaConfig {
    @Bean
    public DefaultKaptcha producer(){

        DefaultKaptcha defaultKaptcha = new DefaultKaptcha();
        Properties properties = new Properties();
        properties.setProperty("kaptcha.border", "no");
        properties.setProperty("kaptcha.border.color", "105,179,90");
        properties.setProperty("kaptcha.textproducer.font.color", "black");
        properties.setProperty("kaptcha.image.width", "110");
        properties.setProperty("kaptcha.image.height", "40");
        properties.setProperty("kaptcha.textproducer.char.string","23456789abcdefghkmnpqrstuvwxyzABCDEFGHKMNPRSTUVWXYZ");
        properties.setProperty("kaptcha.textproducer.font.size", "30");
        properties.setProperty("kaptcha.textproducer.char.space","3");
        properties.setProperty("kaptcha.session.key", "code");
        properties.setProperty("kaptcha.textproducer.char.length", "4");
        properties.setProperty("kaptcha.textproducer.font.names", "宋体,楷体,微软雅黑");
//        properties.setProperty("kaptcha.obscurificator.impl","com.xxx");可以重写实现类
        properties.setProperty("kaptcha.noise.impl","com.google.code.kaptcha.impl.NoNoise");
        Config config = new Config(properties);
        defaultKaptcha.setConfig(config);

        return defaultKaptcha;
    }

1.2.3 验证码控制层

import com.google.code.kaptcha.impl.DefaultKaptcha;
import com.lzp.kaptcha.service.CaptchaService;
import com.lzp.kaptcha.vo.CaptchaVO;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import sun.misc.BASE64Encoder;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

@RestController
@RequestMapping("/captcha")
public class CaptchaController {

    @Autowired
    private DefaultKaptcha producer;

    @Autowired
    private CaptchaService captchaService;

    @ResponseBody
    @GetMapping("/get")
    public CaptchaVO getCaptcha() throws IOException {
        // 生成文字验证码
        String content = producer.createText();
        // 生成图片验证码
        ByteArrayOutputStream outputStream = null;
        BufferedImage image = producer.createImage(content);

        outputStream = new ByteArrayOutputStream();
        ImageIO.write(image, "jpg", outputStream);
        // 对字节数组Base64编码
        BASE64Encoder encoder = new BASE64Encoder();

        String str = "data:image/jpeg;base64,";
        String base64Img = str + encoder.encode(outputStream.toByteArray()).replace("\n", "").replace("\r", "");

        CaptchaVO captchaVO  =captchaService.cacheCaptcha(content);
        captchaVO.setBase64Img(base64Img);
        return  captchaVO;
    }
}

验证码返回对象CaptchaVO

@Data
public class CaptchaVO {
    /**
     * 验证码标识符
     */
    private String captchaKey;
    /**
     * 验证码过期时间
     */
    private Long expire;
    /**
     * base64字符串
     */
    private String base64Img;
}

验证码方法层CaptchaService

import com.lzp.kaptcha.utils.RedisUtils;
import com.lzp.kaptcha.vo.CaptchaVO;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

import java.util.UUID;

@Service
public class CaptchaService {

    @Value("${server.session.timeout:300}")
    private Long timeout;

    @Autowired
    private RedisUtils redisUtils;


    private final String CAPTCHA_KEY = "captcha:verification:";

    public CaptchaVO cacheCaptcha(String captcha){
        //生成一个随机标识符
        String captchaKey = UUID.randomUUID().toString();

        //缓存验证码并设置过期时间
        redisUtils.set(CAPTCHA_KEY.concat(captchaKey),captcha,timeout);
        CaptchaVO captchaVO = new CaptchaVO();
        captchaVO.setCaptchaKey(captchaKey);
        captchaVO.setExpire(timeout);
        return captchaVO;
    }
}

1.2.4 登录控制层

用户登录对象封装LoginDTO

@Data
public class LoginDTO {
    private String userName;
    private String pwd;
    private String captchaKey;
    private String captcha; 
}

import com.lzp.kaptcha.dto.LoginDTO;
import com.lzp.kaptcha.utils.RedisUtils;
import com.lzp.kaptcha.vo.UserVO;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    private RedisUtils redisUtils;

    @PostMapping("/login")
    public UserVO login(@RequestBody LoginDTO loginDTO)  {
        Object captch = redisUtils.get(loginDTO.getCaptchaKey());
        if(captch == null){
            // throw 验证码已过期
        }
        if(!loginDTO.getCaptcha().equals(captch)){
            // throw 验证码错误
        }
        // 查询用户信息

        //判断用户是否存在 不存在抛出用户名密码错误

        //判断密码是否正确，不正确抛出用户名密码错误

        //构造返回到前端的用户对象并封装信息和生成token

        return new UserVO();
    }
}