Druid是阿里巴巴开发的一款数据库连接池，它支持对数据库密码的加密操作，今天我们就一起来实现如何利用Druid对数据库的密码进行加密操作。

1、首先配置Druid的数据库连接池

<!--数据源加密操作-->
<bean id="dbPasswordCallback" class="com.lyz.dbsource.DBPasswordCallback" lazy-init="true"/>

<bean id="statFilter" class="com.alibaba.druid.filter.stat.StatFilter" lazy-init="true">
        <property name="logSlowSql" value="true"/>
        <property name="mergeSql" value="true"/>
    </bean>
<!-- 数据库连接 -->
<bean id="readDataSource" class="com.alibaba.druid.pool.DruidDataSource"
          destroy-method="close" init-method="init" lazy-init="true">
        <property name="driverClassName" value="${driver}"/>
        <property name="url" value="${url1}"/>
        <property name="username" value="${username}"/>
        <property name="password" value="${password}"/>
        <!-- 初始化连接大小 -->
        <property name="initialSize" value="${initialSize}"/>
        <!-- 连接池最大数量 -->
        <property name="maxActive" value="${maxActive}"/>
        <!-- 连接池最小空闲 -->
        <property name="minIdle" value="${minIdle}"/>
        <!-- 获取连接最大等待时间 -->
        <property name="maxWait" value="${maxWait}"/>
        <!-- -->
        <property name="defaultReadOnly" value="true"/>
        <property name="proxyFilters">
            <list>
                <ref bean="statFilter"/>
            </list>
        </property>
        <property name="filters" value="${druid.filters}"/>
        <property name="connectionProperties" value="password=${password}"/>
        <property name="passwordCallback" ref="dbPasswordCallback"/>
        <property name="testWhileIdle" value="true"/>
        <property name="testOnBorrow" value="false"/>
        <property name="testOnReturn" value="false"/>
        <property name="validationQuery" value="SELECT 'x'"/>
        <property name="timeBetweenLogStatsMillis" value="60000"/>
        <!-- 配置一个连接在池中最小生存的时间，单位是毫秒 -->
        <property name="minEvictableIdleTimeMillis" value="${minEvictableIdleTimeMillis}"/>
        <!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 -->
        <property name="timeBetweenEvictionRunsMillis" value="${timeBetweenEvictionRunsMillis}"/>
</bean>

其中要注意的是：

<bean id="dbPasswordCallback" class="com.lyz.dbsource.DBPasswordCallback" lazy-init="true"/>

<property name="connectionProperties" value="password=${password}"/>  
<property name="passwordCallback" ref="dbPasswordCallback"/>

2、使用RSA公钥和私钥，生成一对公钥和私钥的工具类

package com.lyz.crypto.rsa;
import java.security.Key;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.util.HashMap;
import java.util.Map;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;


/**
 * RSA算法
 * @author liuyazhuang
 *
 */
public class RSAKeysUtil {

    public static final String KEY_ALGORITHM = "RSA";
    public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
    private static final String PUBLIC_KEY = "RSAPublicKey";
    private static final String PRIVATE_KEY = "RSAPrivateKey";

    public static void main(String[] args) {
        Map<String, Object> keyMap;
        try {
            keyMap = initKey();
            String publicKey = getPublicKey(keyMap);
            System.out.println(publicKey);
            String privateKey = getPrivateKey(keyMap);
            System.out.println(privateKey);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static String getPublicKey(Map<String, Object> keyMap) throws Exception {
        Key key = (Key) keyMap.get(PUBLIC_KEY);
        byte[] publicKey = key.getEncoded();
        return encryptBASE64(key.getEncoded());
    }

    public static String getPrivateKey(Map<String, Object> keyMap) throws Exception {
        Key key = (Key) keyMap.get(PRIVATE_KEY);
        byte[] privateKey = key.getEncoded();
        return encryptBASE64(key.getEncoded());
    }

    public static byte[] decryptBASE64(String key) throws Exception {
        return (new BASE64Decoder()).decodeBuffer(key);
    }

    public static String encryptBASE64(byte[] key) throws Exception {
        return (new BASE64Encoder()).encodeBuffer(key);
    }

    public static Map<String, Object> initKey() throws Exception {
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
        keyPairGen.initialize(1024);
        KeyPair keyPair = keyPairGen.generateKeyPair();
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
        Map<String, Object> keyMap = new HashMap<String, Object>(2);
        keyMap.put(PUBLIC_KEY, publicKey);
        keyMap.put(PRIVATE_KEY, privateKey);
        return keyMap;
    }
}

运行这个类，输出的结果如下：

Druid之——连接池自定义数据库密码加解密的实现_Druid

上边是公钥下边是私钥。

3、使用私钥对明文密码进行加密

package com.lyz.dbsource.demo;

import com.alibaba.druid.filter.config.ConfigTools;

/**
 * @author liuyazhuang
 *
 */
public class ConfigToolsDemo {
    
    /**
     * 私钥对数据进行加密
     */
    private static final String PRIVATE_KEY_STRING = "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";
    // @Test
//    public void demo() throws Exception {
//        //密码明文，也就是数据库的密码
//        String plainText = "cardiochina.net123456";
//        System.out.printf(ConfigTools.encrypt(PRIVATE_KEY_STRING, plainText));
//    }
    public static void main(String[] args) throws Exception {
         //密码明文，也就是数据库的密码
        String plainText = "root";
        System.out.printf(ConfigTools.encrypt(PRIVATE_KEY_STRING, plainText));
    }
}

结果如下：

Druid之——连接池自定义数据库密码加解密的实现_Druid_02

然后将数据库配置的链接密码改为这个输出结果如下：

jdbc.username=root
jdbc.password=EA9kJ8NMV8zcb5AeLKzAsL/8F1ructRjrqs69zM70BwDyeMtxuEDEVe9CBeRgZ+qEUAshhWGEDk9ay3TLLKrf2AOE3VBn+w8+EfUIEXFy8u3jYViHeV8yc8Z7rghdFShhd/IJbjqbsro1YtB9pHrl4EpbCqp7RM2rZR/wJ0WN48=

4、解析密码的时候需要的Callback类

package com.lyz.dbsource;

import java.util.Properties;

import com.alibaba.druid.filter.config.ConfigTools;
import com.alibaba.druid.util.DruidPasswordCallback;

/**
 * 数据库密码回调
 * @author liuyazhuang
 *
 */
public class DBPasswordCallback extends DruidPasswordCallback {

    private static final long serialVersionUID = -4601105662788634420L;
    
    /**
     * password的属性
     */
    private static final String DB_PWD = "password";
    /**
     * 数据对应的公钥
     */
    public static final String PUBLIC_KEY_STRING = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCratyCT+YnQ12YzC+iPB0wJdIbVmUjjuNy4Wf/rLbCBudFrLltFCdr3axLY70xHycT+jdVTa27BfS67KegOAMlMMdNGVLnk5W1Gl+tNd+A4tCHUNwuEU7eZjyGxd4VCnq7PHLJbYGEeHwcr0dxKuJbfowKJVRypss7n7pB93d7yQIDAQAB";
    
    @Override
    public void setProperties(Properties properties) {
        super.setProperties(properties);
        String pwd = properties.getProperty(DB_PWD);
        if (pwd != null && !"".equals(pwd.trim())) {
            try {
                //这里的password是将jdbc.properties配置得到的密码进行解密之后的值
                //所以这里的代码是将密码进行解密
                //TODO 将pwd进行解密;
                String password = ConfigTools.decrypt(PUBLIC_KEY_STRING, pwd); 
                setPassword(password.toCharArray());
            } catch (Exception e) {
                setPassword(pwd.toCharArray());
            }
        }
    }
//  public static void main(String[] args) throws Exception{
//      System.out.println(ConfigTools.decrypt(PUBLIC_KEY_STRING, "fbTGHjui2zKUOBRiX/XYNvlBXTPGj4vXhOD7oh91cWvBvpf+ZsrAGDcVBwYfs2xqn5tWueC5VAI0o0nglV0R17PIata6OlVOr4hEvqID+x2nbhRBjxSfCMEwvVmdTFXahV1yuMMnLbi7FadbVuq10apTAGY1Ts5Vhuo1fNLyba4="));
//  }
}

其中PasswordCallback是javax.security.auth.callback包下面的，底层安全服务实例化一个 PasswordCallback 并将其传递给 CallbackHandler 的 handle 方法，以获取密码信息。

当然，除了使用上述的方式，自己也可以对应一套加解密方法，只需要在DBPasswordCallback的 String password = ConfigTools.decrypt(PUBLIC_KEY_STRING, pwd); 替换即可。


5、在jdbc.properties存放自己加密之后的信息

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true
username=root

#回调DBPasswordCallback解密，这里的密码是你加密之后的密码！！！
password=EA9kJ8NMV8zcb5AeLKzAsL/8F1ructRjrqs69zM70BwDyeMtxuEDEVe9CBeRgZ+qEUAshhWGEDk9ay3TLLKrf2AOE3VBn+w8+EfUIEXFy8u3jYViHeV8yc8Z7rghdFShhd/IJbjqbsro1YtB9pHrl4EpbCqp7RM2rZR/wJ0WN48=

#定义初始连接数
initialSize=20
#定义最大连接数
maxActive=40
#定义最大空闲
maxIdle=20
#定义最小空闲
minIdle=1
#定义最长等待时间
maxWait=60000

注意：2、3过程中密码的设置要确定，加密、解密的最初始密码是要对应的

6、设置自定义的DruidPasswordCallback

在自己的spring配置文件中加入下边的一句bean配置：

<!--数据源加密操作 这里的class就是第4步中自己创建的-->
<bean id="dbPasswordCallback" class="com.lyz.dbsource.DBPasswordCallback" lazy-init="true"/>

另外还可以直接继承自Spring提供的PropertyPlaceholderConfigurer，摘录别人一段代码大家参考一下： 

public class DecryptPropertyPlaceholderConfigurer extends PropertyPlaceholderConfigurer{
    /**
     * 重写父类方法，解密指定属性名对应的属性值
     */
    @Override
    protected String convertProperty(String propertyName,String propertyValue){
        if(isEncryptPropertyVal(propertyName)){
            return DesUtils.getDecryptString(propertyValue);//调用解密方法
        }else{
            return propertyValue;
        }
    }
    /**
     * 判断属性值是否需要解密，这里我约定需要解密的属性名用encrypt开头
     * @param propertyName
     * @return
     */
    private boolean isEncryptPropertyVal(String propertyName){
        if(propertyName.startsWith("encrypt")){
            return true;
        }else{
            return false;
        }
    }
}