没图不让发文章

小试牛刀

1.构建一个springboot项目,并且引入jasypt依赖

 <dependency>
        <groupId>com.github.ulisesbocchio</groupId>
        <artifactId>jasypt-spring-boot-starter</artifactId>
        <version>3.0.2</version>
</dependency>  

2.编写一个单元测试,用于获取加密后的账号密码

StringEncryptor是jasypt-spring-boot-starter自动配置的加密工具，加密算法我们选择PBEWithHmacSHA512AndAES_128，password为123abc

 jasypt.encryptor.password=123abc
jasypt.encryptor.algorithm=PBEWithHmacSHA512AndAES_128  

 @SpringBootTest
class SpringbootPropertiesEnc application Tests {

    @Autowired
     private  StringEncryptor stringEncryptor;

    @Test
     void  contextLoads() {
        String sunshujie = stringEncryptor.encrypt("sunshujie");
        String qwerty1234 = stringEncryptor.encrypt("qwerty1234");
        System.out.println(sunshujie);
        System.out.println(qwerty1234);
    }

}  

3.在application.properties中配置加密后的账号密码

 jasypt.encryptor.password=123abc
jasypt.encryptor.algorithm=PBEWithHmacSHA512AndAES_128
 username =ENC(pXDnpH3GdMDBHdxraKyAt7IKCeX8mVlM9A9PeI9Ow2VUoBHRESQ5m8qhrbp45vH+)
password=ENC(qD55H3EKYpxp9cGBqpOfR2pqD/AgqT+IyClWKdW80MkHx5jXEViaJTAx6Es4/ZJt)  

4.观察在程序中是否能够拿到解密后的账号密码

 @SpringBootApplication
public class SpringbootPropertiesEncApplication implements CommandLineRunner {
    private  static  final  LOG ger logger = LoggerFactory.getLogger(SpringbootPropertiesEncApplication.class);
    public static void main(String[] args) {
        SpringApplication.run(SpringbootPropertiesEncApplication.class, args);
    }

    @Value("${password}")
    private String password;
    @Value("${username}")
    private String username;

    @Override
    public void run(String... args) throws Exception {
        logger.info("username: {} , password: {} ", username, password);
    }
}  

原理解析

加密原理

首先看jasypt相关的配置,分别是password和加密算法

 jasypt.encryptor.password=123abc
jasypt.encryptor.algorithm=PBEWithHmacSHA512AndAES_128  

PBEWithHmacSHA512AndAES_128是此次我们选用的加密算法.

123abc是PBEWithHmacSHA512AndAES_128加密过程中用的加密密码.

PBE是基于密码的加密算法,密码和秘钥相比有什么好处呢?好处就是好记…

PBE加密流程如下

1. 密码加盐
2. 密码加盐结果做摘要获取秘钥
3. 用秘钥对称加密原文,然后和盐拼在一起得到密文

PBE解密流程如下

1. 从密文获取盐
2. 密码+盐摘要获取秘钥
3. 密文通过秘钥解密获取原文

再来看PBEWithHmacSHA512AndAES_128,名字就是加密过程中用的具体算法

• PBE是指用的是PBE加密算法
• HmacSHA512是指摘要算法,用于获取秘钥
• AES_128是对称加密算法

jasypt-spring-boot-starter原理

先从spring.factories文件入手查看自动配置类

 org.springframework.boot.autoconfigure.EnableAutoConfiguration=com.ulisesbocchio.jasyptspringboot.JasyptSpringBootAutoConfiguration  

JasyptSpringBootAutoConfiguration配置仅仅使用@ Import 注解引入另一个配置类EnableEncryptablePropertiesConfiguration.

 @Configuration
@Import({EnableEncryptablePropertiesConfiguration.class})
public class JasyptSpringBootAutoConfiguration {
    public JasyptSpringBootAutoConfiguration() {
    }
}  

从配置类EnableEncryptablePropertiesConfiguration可以看到有两个操作

1.@Import了EncryptablePropertyResolverConfiguration.class, CachingConfiguration.class

2.注册了一个BeanFactoryPostProcessor -> EnableEncryptablePropertiesBeanFactoryPostProcessor

 @Configuration
@Import({EncryptablePropertyResolverConfiguration.class, CachingConfiguration.class})
public class EnableEncryptablePropertiesConfiguration {
    private static final Logger log = LoggerFactory.getLogger(EnableEncryptablePropertiesConfiguration.class);

    public EnableEncryptablePropertiesConfiguration() {
    }

    @Bean
    public static EnableEncryptablePropertiesBeanFactoryPostProcessor enableEncryptablePropertySourcesPostProcessor(ConfigurableEnvironment environment) {
         boolean  proxyPropertySources = (Boolean)environment.getProperty("jasypt.encryptor.proxy-property-sources", Boolean.TYPE, false);
        InterceptionMode interceptionMode = proxyPropertySources ? InterceptionMode.PROXY : InterceptionMode.WRAPPER;
        return new EnableEncryptablePropertiesBeanFactoryPostProcessor(environment, interceptionMode);
    }
}  

先看EncryptablePropertyResolverConfiguration.class

lazyEncryptablePropertyDetector这里有配置文件中 ENC() 写法的出处.从名称来看是用来找到哪些配置需要解密.

从代码来看,不一定非得用ENC()把密文包起来, 也可以通过配置来指定其他前缀和后缀

 jasypt.encryptor.property.prefix
jasypt.encryptor.property.suffix  

     @Bean(
        name = {"lazyEncryptablePropertyDetector"}
    )
    public EncryptablePropertyDetector encryptablePropertyDetector(EncryptablePropertyResolverConfiguration.EnvCopy envCopy, BeanFactory bf) {
        String prefix = envCopy.get().resolveRequiredPlaceholders("${jasypt.encryptor.property.prefix:ENC(}");
        String suffix = envCopy.get().resolveRequiredPlaceholders("${jasypt.encryptor.property.suffix:)}");
        String customDetectorBeanName = envCopy.get().resolveRequiredPlaceholders(DETECTOR_BEAN_PLACEHOLDER);
        boolean isCustom = envCopy.get().containsProperty("jasypt.encryptor.property.detector-bean");
        return new DefaultLazyPropertyDetector(prefix, suffix, customDetectorBeanName, isCustom, bf);
    }  

另外还配置了很多bean,先记住这两个重要的bean.带着疑问往后看.

• lazyEncryptablePropertyResolver 加密属性解析器
• lazyEncryptablePropertyFilter 加密属性过滤器

     @Bean(
        name = {"lazyEncryptablePropertyResolver"}
    )
    public EncryptablePropertyResolver encryptablePropertyResolver(@Qualifier("lazyEncryptablePropertyDetector") EncryptablePropertyDetector propertyDetector, @Qualifier("lazyJasyptStringEncryptor") StringEncryptor encryptor, BeanFactory bf, EncryptablePropertyResolverConfiguration.EnvCopy envCopy, ConfigurableEnvironment environment) {
        String customResolverBeanName = envCopy.get().resolveRequiredPlaceholders(RESOLVER_BEAN_PLACEHOLDER);
        boolean isCustom = envCopy.get().containsProperty("jasypt.encryptor.property.resolver-bean");
        return new DefaultLazyPropertyResolver(propertyDetector, encryptor, customResolverBeanName, isCustom, bf, environment);
    }

    @Bean(
        name = {"lazyEncryptablePropertyFilter"}
    )
    public EncryptablePropertyFilter encryptablePropertyFilter(EncryptablePropertyResolverConfiguration.EnvCopy envCopy, ConfigurableBeanFactory bf, @Qualifier("configPropsSingleton") Singleton<JasyptEncryptorConfigurationProperties> configProps) {
        String customFilterBeanName = envCopy.get().resolveRequiredPlaceholders(FILTER_BEAN_PLACEHOLDER);
        boolean isCustom = envCopy.get().containsProperty("jasypt.encryptor.property.filter-bean");
        FilterConfigurationProperties filterConfig = ((JasyptEncryptorConfigurationProperties)configProps.get()).getProperty().getFilter();
        return new DefaultLazyPropertyFilter(filterConfig.getIncludeSources(), filterConfig.getExcludeSources(), filterConfig.getIncludeNames(), filterConfig.getExcludeNames(), customFilterBeanName, isCustom, bf);
    }  

再看EnableEncryptablePropertiesBeanFactoryPostProcessor这个类

1. 是一个BeanFactoryPostProcessor
2. 实现了Ordered,是最低优先级,会在其他BeanFactoryPostProcessor执行之后再执行
3. postProcessBeanFactory方法中获取了上面提到的两个重要的bean, lazyEncryptablePropertyResolver lazyEncryptablePropertyFilter
4. 从environment中获取了PropertySources
5. 调用工具类进行转换PropertySources, 也就是把密文转换为原文

 public class EnableEncryptablePropertiesBeanFactoryPostProcessor implements BeanFactoryPostProcessor, Ordered {    
    // ignore some code
    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
        LOG.info("Post-processing PropertySource instances");
        EncryptablePropertyResolver propertyResolver = (EncryptablePropertyResolver)beanFactory.getBean("lazyEncryptablePropertyResolver", EncryptablePropertyResolver.class);
        EncryptablePropertyFilter propertyFilter = (EncryptablePropertyFilter)beanFactory.getBean("lazyEncryptablePropertyFilter", EncryptablePropertyFilter.class);
        MutablePropertySources propSources = this.environment.getPropertySources();
        EncryptablePropertySourceConverter.convertPropertySources(this.interceptionMode, propertyResolver, propertyFilter, propSources);
    }

    public int getOrder() {
        return 2147483547;
    }
}  

再看工具类EncryptablePropertySourceConverter

1.过滤所有已经是EncryptablePropertySource的PropertySource

2.转换为EncryptablePropertySource

3.用EncryptablePropertySource从PropertySources中替换原PropertySource

     public static void convertPropertySources(InterceptionMode interceptionMode, EncryptablePropertyResolver propertyResolver, EncryptablePropertyFilter propertyFilter, MutablePropertySources propSources) {
        ((List)StreamSupport.stream(propSources.spliterator(), false).filter((ps) -> {
            return !(ps instanceof EncryptablePropertySource);
        }).map((ps) -> {
            return makeEncryptable(interceptionMode, propertyResolver, propertyFilter, ps);
        }).collect(Collectors.toList())).forEach((ps) -> {
            propSources.replace(ps.getName(), ps);
        });
    }  

关键方法在makeEncryptable中,调用链路很长, 这里选取一条链路跟一下

1. .ulisesbocchio.jasyptspringboot.EncryptablePropertySourceConverter#makeEncryptable
2. com.ulisesbocchio.jasyptspringboot.EncryptablePropertySourceConverter#convertPropertySource
3. com.ulisesbocchio.jasyptspringboot.EncryptablePropertySourceConverter#proxyPropertySource
4. com.ulisesbocchio.jasyptspringboot.aop.EncryptablePropertySourceMethodInterceptor#invoke
5. com.ulisesbocchio.jasyptspringboot.caching.CachingDelegateEncryptablePropertySource#getProperty
6. com.ulisesbocchio.jasyptspringboot.EncryptablePropertySource#getProperty()

看到最后豁然开朗,发现就是用的最开始配置的DefaultLazyPropertyResolver进行密文解析.

直接看最终的实现 DefaultPropertyResolver

1. 据lazyEncryptablePropertyDetector过滤需要解密的配置
2. 用lazyEncryptablePropertyDetector去掉前缀后缀
3. 替换占位符
4. 解密

     public String resolvePropertyValue(String value) {
        Optional var10000 = Optional.ofNullable(value);
        Environment var10001 = this.environment;
        var10001.getClass();
        var10000 = var10000.map(var10001::resolveRequiredPlaceholders);
        EncryptablePropertyDetector var2 = this.detector;
        var2.getClass();
        return (String)var10000.filter(var2::isEncrypted).map((resolvedValue) -> {
            try {
                String unwrappedProperty = this.detector.unwrapEncryptedValue(resolvedValue.trim());
                String resolvedProperty = this.environment.resolveRequiredPlaceholders(unwrappedProperty);
                return this.encryptor.decrypt(resolvedProperty);
            } catch (EncryptionOperationNotPossibleException var5) {
                throw new DecryptionException("Unable to decrypt: " + value + ". Decryption of Properties failed,  make sure encryption/decryption passwords match", var5);
            }
        }).orElse(value);
    }  

解惑

1.加密配置文件能否使用摘要算法,例如md5?

不能, 配置文件加密是需要解密的,例如数据库连接信息加密,如果不解密,springboot程序无法读取到真正的数据库连接信息,也就无法建立连接.

2.加密配置文件能否直接使用对称加密,不用PBE?

可以, PBE的好处就是密码好记.

3.jasypt.encryptor.password可以泄漏吗?

不能, 泄漏了等于没有加密.

4.例子中jasypt.encryptor.password配置在配置文件中不就等于泄漏了吗?

是这样的,需要在流程上进行控制.springboot打包时 千万不要 把jasypt.encryptor.password打入jar包内.

在公司具体的流程可能是这样的:

• 运维人员持有jasypt.encryptor.password,加密原文获得密文
• 运维人员将密文发给开发人员
• 开发人员在配置文件中只配置密文, 不配置 jasypt.encryptor.password
• 运维人员 启动应用时再配置 jasypt.encryptor.password

如果有其他疑惑欢迎留言提问, 另外由于作者水平有限难免有疏漏, 欢迎留言纠错。