Integrating Jasypt with Spring 3.0

Jasypt provides the jasypt-spring3 artifact for integration with Spring Framework 3.0. Since jasypt 1.9.0, this artifact must be added to your classpath separately.

Using jasypt digesters and encryptors as Spring beans

You have nothing special to do register jasypt beans in Spring, as all of the encryption tools (digesters and encryptors) in jasypt have the adequate design to be correctly instantiated and dependency-injected from a Spring application context.

Example:

  <bean id="strongEncryptor"
    class="org.jasypt.encryption.pbe.StandardPBEStringEncryptor">
    <property name="algorithm">
        <value>PBEWithMD5AndTripleDES</value>
    </property>
    <property name="password">
        <value>jasypt</value>
    </property>
  </bean>

Besides, all digesters and encryptors in jasypt are thread-safe, which means that they can be safely treated as singletons, the default behaviour of Spring's bean container. This avoids concurrency problems in multi-threaded environments like web applications.

Integrating jasypt with Spring's application configuration infrastructure (without using the encryption namespace)

Jasypt provides several Spring-specific configuration management classes:

  • org.jasypt.spring3.properties.EncryptablePropertyPlaceholderConfigurer, as a totally compatible replacement for Spring's PropertyPlaceholderConfigurer.
  • org.jasypt.spring3.properties.EncryptablePropertyOverrideConfigurer, as a totally compatible replacement for Spring's PropertyOverrideConfigurer.
  • org.jasypt.spring3.properties.EncryptableServletContextPropertyPlaceholderConfigurer: as a totally compatible replacement for Spring's ServletContextPropertyPlaceholderConfigurer.
  • org.jasypt.spring3.properties.EncryptablePreferencesPlaceholderConfigurer: as a totally compatible replacement for Spring's PreferencesPlaceholderConfigurer.

Their use is analogue to the Spring equivalents, but we can use them to read encrypted property values from our configuration files and apply them to our beans.

Note that we can also make use of these integrations using a specific namespace in the Spring XML files called encryption, which is explained in detail below.

If we have the properties file seen before (application.properties):

 datasource.driver=com.mysql.jdbc.Driver
 datasource.url=jdbc:mysql://localhost/reportsdb
 datasource.username=reportsUser
 datasource.password=ENC(G6N718UuyPE5bHyWKyuLQSm02auQPUtm)

We can define in our Spring context configuration:

  
 <!--                                                                      -->
 <!-- Configuration for encryptor, based on environment variables.         -->
 <!--                                                                      -->
 <!-- In this example, the encryption password will be read from an        -->
 <!-- environment variable called "APP_ENCRYPTION_PASSWORD" which, once    --> 
 <!-- the application has been started, could be safely unset.             -->
 <!--                                                                      -->
 <bean id="environmentVariablesConfiguration"
     class="org.jasypt.encryption.pbe.config.EnvironmentStringPBEConfig">
   <property name="algorithm" value="PBEWithMD5AndDES" />
   <property name="passwordEnvName" value="APP_ENCRYPTION_PASSWORD" />
 </bean>
  
  
 <!--                                                                      -->
 <!-- The will be the encryptor used for decrypting configuration values.  -->
 <!--                                                                      -->
 <bean id="configurationEncryptor"
     class="org.jasypt.encryption.pbe.StandardPBEStringEncryptor">
   <property name="config" ref="environmentVariablesConfiguration" />
 </bean>


 <!--                                                                      -->
 <!-- The EncryptablePropertyPlaceholderConfigurer will read the           -->
 <!-- .properties files and make their values accessible as ${var}         -->
 <!--                                                                      -->
 <!-- Our "configurationEncryptor" bean (which implements                  --> 
 <!-- org.jasypt.encryption.StringEncryptor) is set as a constructor arg.  -->
 <!--                                                                      -->
 <bean id="propertyConfigurer"
     class="org.jasypt.spring3.properties.EncryptablePropertyPlaceholderConfigurer">
   <constructor-arg ref="configurationEncryptor" />
   <property name="locations">
     <list>
       <value>/WEB-INF/classes/application.properties</value>
     </list>
   </property>
   
 </bean>


 <!--                                                                      -->
 <!-- Our datasource is configured here, in the usual way. Jasypt's        -->
 <!-- EncryptedPropertyPlaceholderConfigurer will make sure that the       -->
 <!-- ${datasource.password} file gets decrypted and the DBCP DataSource   -->
 <!-- will be correctly initialised.                                       -->
 <!--                                                                      -->
 <bean id="dataSource"
     class="org.apache.commons.dbcp.BasicDataSource"
     destroy-method="close">
   <property name="driverClassName">
     <value>${datasource.driver}</value>
   </property>
   <property name="url">
     <value>${datasource.url}</value>
   </property>
   <property name="username">
     <value>${datasource.username}</value>
   </property>
   <property name="password">
     <value>${datasource.password}</value>
   </property>
 </bean>
        

EncryptablePropertyPlaceholderConfigurer and EncryptablePropertyOverrideConfigurer objects can receive as a constructor argument both an org.jasypt.encryption.StringEncryptor implementation or an org.jasypt.util.TextEncryptor object.

Encryptable ServletContextPropertyPlaceholderConfigurer implementation for Spring

Jasypt includes org.jasypt.spring3.properties.EncryptableServletContextPropertyPlaceholderConfigurer, a subclass of org.springframework.web.context.support.ServletContextPropertyPlaceholderConfigurer which allows the transparent decryption of servlet context parameters in web applications (for example, parameters in WEB-INF/web.xml).

These encrypted parameters can be specified in a way equivalent to that of encrypted parameters in .properties files:

    ...
    <context-param>
        <param-name>someParameter</param-name>
        <param-value>ENC(...)</param-value>
    </context-param>
    ...

Encryptable PreferencesPlaceholderConfigurer implementation for Spring

Jasypt includes org.jasypt.spring3.properties.EncryptablePreferencesPlaceholderConfigurer, a subclass of org.springframework.beans.factory.config.PreferencesPlaceholderConfigurer which allows the transparent decryption preferences set with JDK 1.4's Preferences API.

The encryption namespace

The jasypt-spring3 library includes a namespace you can use in your Spring XML files in order to make the declaration of your jasypt entities much easier.

This namespace can be included in your XML like this:

<beans xmlns="http://www.springframework.org/schema/beans"
       ...
       xmlns:encryption="http://www.jasypt.org/schema/encryption"
       ...
       xsi:schemaLocation="http://www.springframework.org/schema/beans
                           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
                           ...
                           http://www.jasypt.org/schema/encryption
                           http://www.jasypt.org/schema/encryption/jasypt-spring3-encryption-1.xsd
                           ...">

Once declared, you will be able to use <encryption:*> tags for:

  • Creating encryptors and digesters.
  • Creating configuration beans, both for encryptors and for digesters.
  • Creating instances of EncryptableProperties (extending java.util.Properties) that automatically decrypt entries in .properties files.
  • Registering an EncryptablePropertyPlaceHolderConfigurer.

Creating encryptors and digesters

Creating encryptor and digester artifacts with the encryption namespace is easy. There's a tag for each type of encryptor/digester (including some util classes), and each tags is able to specify all of the artifact's properties as tag attributes.

Let's see some encryptor declaration examples:

  <!-- Registers an org.jasypt.encryption.ByteEncryptor-->
  <encryption:byte-encryptor id="myEncryptor" algorithm="PBEWithMD5AndTripleDES" password="jasypt"/>
  
  <!-- Registers an org.jasypt.encryption.StringEncryptor-->
  <encryption:string-encryptor id="myEncryptor" password="jasypt" pool-size="5"/>
  
  <!-- Registers an org.jasypt.encryption.BigDecimalEncryptor-->
  <encryption:big-decimal-encryptor password="jasypt" key-obtention-iterations="15000"/>
  
  <!-- Registers an org.jasypt.encryption.BigIntegerEncryptor-->
  <encryption:big-integer-encryptor id="myEncryptor" password="jasypt" provider-name="BC"/>

Note how the pool-size parameter will affect the specific implementation of encryptor being created: a PooledPBE*Encryptor if this parameter is specified, and a StandardPBE*Encryptor if not.

Now for some digesters:

  <!-- Registers an org.jasypt.digest.ByteDigester-->
  <encryption:byte-digester algorithm="SHA-1" salt-size-bytes="16" iterations="50000"/>
  
  <!-- Registers an org.jasypt.digest.StringDigester-->
  <encryption:string-digester pool-size="10"/>

Again, the pool-size attribute will determine whether the digesters will be Standard or Pooled.

Some util artifacts can also be instantiated this way:

  <!-- Password encryptors -->
  <encryption:basic-password-encryptor/>
  <encryption:strong-password-encryptor/>
  <encryption:configurable-password-encryptor/>
  
  <!-- Text encryptors -->
  <encryption:basic-text-encryptor password="jasypt"/>
  <encryption:strong-text-encryptor password="jasypt"/>

Creating configuration beans for encryptors and digesters

Configuration beans implement the DigesterConfig interface for digesters and PBEConfig for encryptors, and Jasypt offers several implementations of these interfaces out-of-the-box depending on whether the digester to be created is meant for bytes or Strings, and also whether some configuration parameters can come from environment variables and/or system properties.

The encryption namespace will automatically choose the correct config bean implementation to be instantiated depending on the specified configuration attributes, so that you do not have to worry about the specific implementation class you need.

Let's see some examples:

  <encryption:digester-config id="dConf1" iterations="1400" salt-size-bytes="32"/>
  <encryption:digester-config id="dConf2" iterations="10000" string-output-type="hexa"/>
  <encryption:digester-config id="dConf3" string-output-type="hexa" algorithm-env-name="VAR_ALGORITHM"/> 
   
  <encryption:encryptor-config id="eConf1" key-obtention-iterations="500" password-env-name="VAR_PASSWD"/> 
  <encryption:encryptor-config id="eConf2" password-env-name="VAR_PASSWD" algorithm="PBEWithMD5AndTripleDES"/> 
  <encryption:encryptor-config id="eConf3" password="jasypt" algorithm-sys-property-name="jasypt.enc.algorithm"/> 

Using these beans in our encryptors/digesters is easy:

  <encryption:digester-config id="dConf" string-output-type="hexa" algorithm-env-name="VAR_ALGORITHM"/>
  <encryption:string-digester config-bean="dConf"/>
   
  <encryption:encryptor-config id="eConf" password-env-name="VAR_PASSWD" algorithm="PBEWithMD5AndTripleDES"/>
  <encryption:string-encryptor id="stringEnc" config-bean="eConf"/> 

Creating EncryptableProperties instances

Usually, in Spring you can create a java.util.Properties bean in your XML using the util namespace, like this:

  <util:properties location="classpath:application.properties"/>

Jasypt allows you to register an org.jasypt.properties.EncryptableProperties object in an equivalent manner, simply by adding an encryptor bean reference:

  <encryption:encryptable-properties encryptor="stringEnc" location="classpath:application.properties"/>

This <encryption:encryptable-properties> tag works in exactly the same way and with exactly the same features as <util:properties>, and as the object it registers is a subclass of java.util.Properties, you can autowire it inside your application with your code not even noticing these properties are originally encrypted.

Registering an EncryptablePropertyPlaceholder/Override

Spring allows you to easily register a PropertyPlaceholderConfigurer that takes care of the resolution of your ${...} property expressions:

  <context:property-placeholder location="classpath:application.properties"/>

But if you want to register an EncryptablePropertyPlaceholder instead because your property files might be encrypted, you can do:

  <encryption:encryptable-property-placeholder encryptor="stringEnc" location="classpath:application.properties"/>

And that's it! A property override implementation is also provided:

  <encryption:encryptable-property-override encryptor="stringEnc" location="classpath:application.properties"/>

Integrating jasypt with Spring Security 3.x

For details on how to integrate jasypt with Spring Security 3.x, please have a look at this guide.