注解方式实现数据库字段加密与解密

悠悠 2024-03-17 21:37 126阅读 0赞

#### 目录 ####

*  前言
 *  实现步骤
 *   *  定义注解
     *  加密工具类
     *  定义mybatis拦截器
 *  总结

## 前言 ##

一些敏感信息存入数据需要进行加密处理，比如电话号码，身份证号码等，从数据库取出到前端展示时需要解密，如果分别在存入取出时去做处理，会很繁锁，至此，我查了很多相关资料，最后得到一个比较完美的解决方案。

## 实现步骤 ##

### 定义注解 ###

1、实体注解@SensitiveEntity

import java.lang.annotation.*;
    
    @Target({
        ElementType.TYPE, ElementType.PARAMETER})
    @Retention(RetentionPolicy.RUNTIME)
    @Inherited
    @Documented
    public @interface SensitiveEntity {
        
    
    }

2、字段注解@SensitiveEntity

import java.lang.annotation.*;
    
    @Target({
        ElementType.FIELD})
    @Retention(RetentionPolicy.RUNTIME)
    @Inherited
    @Documented
    public @interface SensitiveField {
        
    
    }

### 加密工具类 ###

AesFieldUtils.java

import lombok.extern.slf4j.Slf4j;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.stereotype.Component;
    import org.springframework.util.Base64Utils;
    
    import javax.crypto.Cipher;
    import javax.crypto.spec.SecretKeySpec;
    import java.util.regex.Matcher;
    import java.util.regex.Pattern;
    
    
    @Slf4j
    @Component
    public class AesFieldUtils {
        
        /**
         * 加密算法
         */
        private final String KEY_ALGORITHM = "AES";
        /**
         * 算法/模式/补码方式
         */
        private final String DEFAULT_CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";
        /**
         * 编码格式
         */
        private final String CODE = "utf-8";
        /**
         * base64验证规则
         */
        private static final String BASE64_RULE = "^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)=?$";
    
        /**
         * 正则验证对象
         */
        private static final Pattern PATTERN = Pattern.compile(BASE64_RULE);
        /**
         * 加解密 密钥key
         */
        @Value("${aes.key}")
        private String key;
    
    
        /**
         * @param content 加密字符串
         * @return 加密结果
         */
        public String encrypt(String content) {
        
            return encrypt(content, key);
        }
    
        /**
         * 加密
         *
         * @param content 加密参数
         * @param key     加密key
         * @return 结果字符串
         */
        public String encrypt(String content, String key) {
        
            //判断如果已经是base64加密字符串则返回原字符串
            if (isBase64(content)) {
        
                return content;
            }
            // 为了安全起见，暂时不加密，需要时再放开
            //return content;
             byte[] encrypted = encrypt2bytes(content, key);
            if (null == encrypted || encrypted.length < 1) {
        
                log.error("加密字符串[{}]转字节为null", content);
                return null;
            }
            return Base64Utils.encodeToString(encrypted);
    
        }
    
        /**
         * @param content 加密字符串
         * @param key     加密key
         * @return 返回加密字节
         */
        public byte[] encrypt2bytes(String content, String key) {
        
            try {
        
                byte[] raw = key.getBytes(CODE);
                SecretKeySpec secretKeySpec = new SecretKeySpec(raw, KEY_ALGORITHM);
                Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
                cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
                return cipher.doFinal(content.getBytes(CODE));
            } catch (Exception e) {
        
                log.error("failed to encrypt: {} of {}", content, e);
                return null;
            }
        }
    
        /**
         * @param content 加密字符串
         * @return 返回加密结果
         */
        public String decrypt(String content) {
        
            try {
        
                return decrypt(content, key);
            } catch (Exception e) {
        
                log.error("failed to decrypt: {}, e: {}", content, e);
                return null;
            }
        }
    
        /**
         * 解密
         *
         * @param content 解密字符串
         * @param key     解密key
         * @return 解密结果
         */
        public String decrypt(String content, String key) throws Exception {
        
            //不是base64格式字符串则不进行解密
            if (!isBase64(content)) {
        
                return content;
            }
            // 为了安全起见，暂时不加密解密，需要时再放开
            //return content;
            return decrypt(Base64Utils.decodeFromString(content), key);
        }
    
        /**
         * @param content 解密字节
         * @param key     解密key
         * @return 返回解密内容
         */
        public String decrypt(byte[] content, String key) throws Exception {
        
            if (key == null) {
        
                log.error("AES key should not be null");
                return null;
            }
    
            byte[] raw = key.getBytes(CODE);
            SecretKeySpec keySpec = new SecretKeySpec(raw, KEY_ALGORITHM);
            Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
            cipher.init(Cipher.DECRYPT_MODE, keySpec);
            try {
        
                byte[] original = cipher.doFinal(content);
                return new String(original, CODE);
            } catch (Exception e) {
        
                log.error("failed to decrypt content: {}/ key: {}, e: {}", content, key, e);
                return null;
            }
        }
    
        /**
         * 判断是否为 base64加密
         *
         * @param str 参数
         * @return 结果
         */
        public static boolean isBase64(String str) {
        
            Matcher matcher = PATTERN.matcher(str);
            return matcher.matches();
        }
    
    }

其中aes.key为加密key随便填

### 定义mybatis拦截器 ###

MyBatisInterceptor.java

import cn.hutool.core.util.ReflectUtil;
    import com.hw.common.annotation.SensitiveEntity;
    import com.hw.common.service.AesService;
    import lombok.extern.slf4j.Slf4j;
    import org.apache.ibatis.binding.MapperMethod;
    import org.apache.ibatis.executor.parameter.ParameterHandler;
    import org.apache.ibatis.executor.resultset.ResultSetHandler;
    import org.apache.ibatis.executor.statement.StatementHandler;
    import org.apache.ibatis.mapping.BoundSql;
    import org.apache.ibatis.plugin.*;
    import org.springframework.core.annotation.AnnotationUtils;
    import org.springframework.stereotype.Component;
    import org.springframework.util.CollectionUtils;
    
    import javax.annotation.Resource;
    import java.lang.reflect.Field;
    import java.sql.Connection;
    import java.sql.PreparedStatement;
    import java.sql.Statement;
    import java.util.ArrayList;
    import java.util.Objects;
    import java.util.Properties;
    
    @Component
    @Intercepts({
        
            @Signature(type = StatementHandler.class, method = "prepare", args = {
        Connection.class, Integer.class}),
            @Signature(type = ParameterHandler.class, method = "setParameters", args = PreparedStatement.class),
            @Signature(type = ResultSetHandler.class, method = "handleResultSets", args = {
        Statement.class})
    })
    @Slf4j
    public class MyBatisInterceptor implements Interceptor {
        
        @Resource
        private AesService aesService;
    
        @Override
        public Object intercept(Invocation invocation) throws Throwable {
        
            Object target = invocation.getTarget();
            //拦截sql结果处理器
            if (target instanceof ResultSetHandler) {
        
                return resultDecrypt(invocation);
            }
            //拦截sql参数处理器
            if (target instanceof ParameterHandler) {
        
                return parameterEncrypt(invocation);
            }
            //拦截sql语句处理器
            if (target instanceof StatementHandler) {
        
                return replaceSql(invocation);
            }
            return invocation.proceed();
        }
    
        /**
         * 对mybatis映射结果进行字段解密
         *
         * @param invocation 参数
         * @return 结果
         * @throws Throwable 异常
         */
        private Object resultDecrypt(Invocation invocation) throws Throwable {
        
            //取出查询的结果
            Object resultObject = invocation.proceed();
            if (Objects.isNull(resultObject)) {
        
                return null;
            }
            //基于selectList
            if (resultObject instanceof ArrayList) {
        
                ArrayList resultList = (ArrayList) resultObject;
                if (CollectionUtils.isEmpty(resultList)) {
        
                    return resultObject;
                }
                for (Object result : resultList) {
        
                    if (needToDecrypt(result)) {
        
                        //逐一解密
                        aesService.decrypt(result);
                    }
                }
                //基于selectOne
            } else {
        
                if (needToDecrypt(resultObject)) {
        
                    aesService.decrypt(resultObject);
                }
            }
            return resultObject;
        }
    
        /**
         * mybatis映射参数进行加密
         *
         * @param invocation 参数
         * @return 结果
         * @throws Throwable 异常
         */
        private Object parameterEncrypt(Invocation invocation) throws Throwable {
        
            //@Signature 指定了 type= parameterHandler 后，这里的 invocation.getTarget() 便是parameterHandler
            //若指定ResultSetHandler ，这里则能强转为ResultSetHandler
            ParameterHandler parameterHandler = (ParameterHandler) invocation.getTarget();
            // 获取参数对像，即 mapper 中 paramsType 的实例
            Field parameterField = parameterHandler.getClass().getDeclaredField("parameterObject");
            parameterField.setAccessible(true);
            //取出实例
            Object parameterObject = parameterField.get(parameterHandler);
    
            if(parameterHandler.getParameterObject() instanceof MapperMethod.ParamMap){
        
                MapperMethod.ParamMap paramMap = (MapperMethod.ParamMap) parameterHandler.getParameterObject();
                parameterObject = paramMap.get("param1");
            }
            if (null == parameterObject) {
        
                return invocation.proceed();
            }
            Class<?> parameterObjectClass = parameterObject.getClass();
            //校验该实例的类是否被@SensitiveEntity所注解
            SensitiveEntity sensitiveEntity = AnnotationUtils.findAnnotation(parameterObjectClass, SensitiveEntity.class);
            //未被@SensitiveEntity所注解 则为null
            if (Objects.isNull(sensitiveEntity)) {
        
                return invocation.proceed();
            }
            //取出当前当前类所有字段，传入加密方法
            //Field[] declaredFields = parameterObjectClass.getDeclaredFields();
            Field[] allFields = ReflectUtil.getFields(parameterObjectClass);
            aesService.encrypt(allFields, parameterObject);
            return invocation.proceed();
        }
    
        /**
         * 替换mybatis Sql中的加密Key
         *
         * @param invocation 参数
         * @return 结果
         * @throws Throwable 异常
         */
        private Object replaceSql(Invocation invocation) throws Throwable {
        
            StatementHandler statementHandler = (StatementHandler) invocation.getTarget();
            BoundSql boundSql = statementHandler.getBoundSql();
            //获取到原始sql语句
            String sql = boundSql.getSql();
            if (null == sql){
        
                return invocation.proceed();
            }
            //通过反射修改sql语句
            Field field = boundSql.getClass().getDeclaredField("sql");
            field.setAccessible(true);
            field.set(boundSql, sql);
            return invocation.proceed();
        }
    
        /**
         * 判断是否包含需要加解密对象
         *
         * @param object 参数
         * @return 结果
         */
        private boolean needToDecrypt(Object object) {
        
            if(Objects.isNull(object)){
        
                return false;
            }
            Class<?> objectClass = object.getClass();
            Class<?> parentClass = objectClass.getSuperclass();
            SensitiveEntity sensitiveEntity = AnnotationUtils.findAnnotation(objectClass, SensitiveEntity.class);
            SensitiveEntity parentSensitiveEntity = AnnotationUtils.findAnnotation(parentClass, SensitiveEntity.class);
    
            return Objects.nonNull(sensitiveEntity) || Objects.nonNull(parentSensitiveEntity);
        }
    
        @Override
        public Object plugin(Object target) {
        
            return Plugin.wrap(target, this);
        }
    
        @Override
        public void setProperties(Properties properties) {
        
    
        }
    
    }

## 总结 ##

mybatis拦截器非常强大，它可以对所有存入数据库的数据进行处理，包括更新，插入，查询和删除…,对数据做统一处理非常方便。