Spring Security - conditional WebApplicationInitializer - spring

The documentation for Spring Security states that in order to use the Java Config we can extend the AbstractSecurityWebApplicationInitializer class which will set up all nesesarry beans for Spring Security to work. This approach is working fine, the initializer is run automatically and Spring Security is initialized correctly during application startup.
But right now i am facing a scenario when this initialization should be depended on a system property. So i would like to include my initializer class only when some system property is set (for example: app.enablesecurity=true) and NOT execute this initializer in any other case.
I failed to come up with any solution for that scenario because:
In AbstractSecurityWebApplicationInitializer the onStartup method is
marked final so i cannot override it and add a condition
If i just extend AbstractSecurityWebApplicationInitializer it is
always automatically picked up by Spring and instantiated (or at least Spring tries to create instance of it, it may fail), even if i
declare it as a private/inner/nested class.
So as far as i know the only possibility of conditionally including this initializer is to use cglib/javassist in order to dynamically create a class that extends AbstractSecurityWebApplicationInitializer.
Is there any other way? Maybe there is some method that will allow me to hide my implementation from being picked up by Spring and run it by hand at a later time?

You can use Config Class like this to configure your security behavior
#Configuration
#EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
#Value("${app.enablesecurity}")
private boolean securityEnabled;
#Override
protected void configure(HttpSecurity http) throws Exception {
if (securityEnabled) {
http.csrf().disable();
...
} else {
http. ...
}
}
}

Related

Spring MVC #Value/#ConfigurationProperties working on MainConfig but not on SecurityConfig

I have a simple Spring MVC 5 project, with security layer enabled. Everything works good except the properties loading, only on Security Config.
I let you the scenario so you can see it.
application.properties (located at src/main/resources)
com.company.myapp.prop=myprop
MainConfig.java
#Configuration
public class MainConfig implements WebMvcConfigurer {
#Value("${com.company.myapp.prop}")
private String prop;
#Bean
public MySpecialBean mySpecialBean() {
System.out.println(prop); // output > myprop
return new MySpecialBean();
}
}
SecurityConfig.java
#Configuration
#EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
#Value("${com.company.myapp.prop}")
private String prop;
#Bean
public MySpecialSecurityBean mySpecialSecurityBean() {
System.out.println(prop); // output > null
return new MySpecialSecurityBean();
}
}
I don't understand why it's happening. I already switched the #EnableWebSecurity annotation to the app class, try to set the PropertySourcesPlaceholderConfigurer myself, but nothing works.
Do you have any idea what's going on?
From official docs about #PropertySource:
Resolving ${...} placeholders in <bean> and #Value annotations
In order to resolve ${...} placeholders in definitions or #Value annotations using properties from a PropertySource, you must ensure that an appropriate embedded value resolver is registered in the BeanFactory used by the ApplicationContext. This happens automatically when using in XML. When using #Configuration classes this can be achieved by explicitly registering a PropertySourcesPlaceholderConfigurer via a static #Bean method. Note, however, that explicit registration of a PropertySourcesPlaceholderConfigurer via a static #Bean method is typically only required if you need to customize configuration such as the placeholder syntax, etc. See the "Working with externalized values" section of #Configuration's javadocs and "a note on BeanFactoryPostProcessor-returning #Bean methods" of #Bean's javadocs for details and examples.
You should try to add annotation #PropertySource into the your config class.
#Configuration
#PropertySource("classpath:my.properties")
public class MainConfig implements WebMvcConfigurer {}
and then try to access your property in SecurityConfig class
To get full information see official docs
I hope it will help you
This works for me.
I guess you have another class that triggers the application and that is annotated with #SpringBootApplication
Also, your methods mySpecialBean do not return a MySpecialBean instance, so this probably does not even compile.
Is there any other class that you are using? Please advice
Finally got it!
The problem was related with some dependency priorities and unnecessary beans declarations. Getting into details, I'm working with OAuht2 and I started with this tutorial. In the end I've made a mix with this one too (more recent). The problem was related with these #Bean's that don't really need to be declared as beans:
ClientRegistrationRepository
ClientRegistration
OAuth2AuthorizedClientService
Spring was calling these beans before any other configuration, so any properties was not loaded yet. Maybe changing the priority, dependence or even the order would resolve the issue, but as I was analysing the code I found that these methods are only used on security configuration and not really needed along any other part of the app. So I removed the #Bean declaration and all works nice now! At the time these methods are called inside security config the properties are already loaded.
Hope to help someone out there.

Can I get another #Configuration only through #ComponentScan

I am using spring-boot 2.0.4; I have a bunch of services and they have a common configuration class marked with #Configuration.
I want to move this to a common dependency which will have this #Configuration, and based on the need, any micro-service can use #ComponentScan to activate this configuration from dependency.
I have done this for #Component classes, and it's working fine. I activate any particular component I need by adding it into #ComponentScan. How can I activate the configuration in a similar manner(based on need).
Here are the code examples:
Common Configuration:
package abc.department.common.configs.mongo
#Component
public class AbcMongo {
#Bean
public MongoTemplate mongoTemplate() {
// ... create MongoTemplate.
return createdMongoTemplate;
}
}
Here is a class which uses the above dependency:
#Configuration
#ComponentScan("abc.department.common.configs.mongo")
public class MyServiceConfigs {
}
Similarly, I want to do something like this:
package abc.department.common.configs.security.web
#Configuration
#EnableWebSecurity
public class AbcWebSecurity extends WebSecurityConfigurerAdapter {
#Override
protected void configure(HttpSecurity http) throws Exception {
// ... do common configs;
}
}
and now, if a service would need web-security config, it could get like:
#Configuration
#ComponentScan({"abc.department.common.configs.mongo","abc.department.common.configs.security.web"})
public class MyServiceConfigs {
}
#Configuration is meant to specify the beans, for example:
#Configuration
public class MyMongoConfiguration {
#Bean
public MongoTemplate mongoTemplate() {
return new ...
}
#Bean
public MySampleBean mySampleBean(MongoTemplate tpl) {
return new MySampleBean(tpl);
}
}
But if so why do you need to work with #Component at all (at least for the beans you create)?
Configuration is a special bean used by Spring framework to load other beans and it can be viewed as a "substitution"/alternative technique to component scanning.
I believe that, if you have some infrastructure configuration that loads a bunch of "infrastructure beans" (shared jar if I get you right), then the services that use this jar should only say "Hey, I want to load this configuration" and not to scan inside the packaging structure of that jar. Why do I think so?
What if you decide to add new beans into a new package in the infra, should external services change their code and define an additional folder to scan? - Probably no.
What if you decide to move the infra to another package?
Now in Spring there are two simple ways to do this that come to mind:
Way 1: Use #Import Annotation
#Configuration // this is from "shared artifact"
class MyInfraConfiguration {
}
#Configuration // this is from an "applicative service" that uses the infra jar in dependencies
#Import(MyInfraConfiguration.class)
class ServiceAConfiguration {
}
Way 2: Use Spring Factories mechanism
The first way has a drawback: You need to know in a Service what infra configuration exactly is. If you see it as a drawback, consider using spring factories.
Spring factories allow registering the infra configuration in some file so that spring boot will load it in service one automatically, you won't even need to mention MyInfraConfiguration in the Service Configuration, just add a dependency to the infra jar and it will work.
In the infra component create:
META-INF/spring.factories
And add there:
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
com.mycompany.myinfra.whatever.InfraConfiguration
That's it.
Now if you want to customize the loading of beans in the infra configuration, like, a creation of Mongo related templates only if some properties are available, you might want to use #Conditional. Now, although this is kind of out of scope for this question, I mention this because in conjunction with spring factories this can create a very flexible way to manage your configurations

How to handle security.enable-csrf in Spring Boot 2?

I'm migrating an application from Spring Boot 1.5 to 2.0.5.
I have a property set as security.enable-csrf=true in 1.5 version which is not available in 2.0 version of Spring Boot.
I read the documents and it is said that in Spring Boot 2.0:
CSRF protection is enabled by default in the Java configuration.
So by default it is enabled ok fine, but there is also one class created which extends WebSecurityConfigurerAdapter this means Spring Boot default security configuration has been turned off. Is this also means security.enable-csrf is disabled now?
If yes how do I enable it like I had it in the application for 1.5 version.
I didn't get any document which gives a clear confirmation on how to handle security.enable-csrf property in Spring Boot 2.0 and while declaring the WebSecurityConfigurerAdapter.
Does anyone know about it? Also any document link which I have missed to read about this would be great help.
In order to have backward compatibility with the property already been set in you application, security.enable-csrf=true, you can use the following code:
#EnableWebSecurity
public class WebSecurityConfig extends
WebSecurityConfigurerAdapter {
#Value("${security.enable-csrf}")
private boolean csrfEnabled;
#Override
protected void configure(HttpSecurity http) throws Exception {
if (!csrfEnabled) {
http.csrf().disable();
}
}
}
As you might guess the magic comes from http.csrf().disable(); that
in the above code you can control enabling/disabling it by the
property you have set in you application.properties file.
More Info:
For more details you can also refer to the spring documents:
https://docs.spring.io/spring-security/site/docs/current/reference/htmlsingle/#csrf
WebSecurityConfigurerAdapter is an abstract class, when you create a class which extends WebSecurityConfigurerAdapter, you will override void configure(HttpSecurity http) method.
You can disable csrf in this method, like that;
http.csrf().disable();
You can read this comment on top of the csrf() method (in HttpSecurity class).
Adds CSRF support. This is activated by default when using
WebSecurityConfigurerAdapter's default constructor. You can disable it ...."
This comment says that, when you extends this class, default constructor of WebSecurityConfigurerAdapter works and csrf is activated.

When use AbstractAnnotationConfigDispatcherServletInitializer and WebApplicationInitializer?

I am working with Spring 4.0.7
I did a research about configure Spring MVC through JavaConfig.
Practically until yesterday I have seen two configurations using these two options
extends AbstractAnnotationConfigDispatcherServletInitializer
extends WebMvcConfigurerAdapter and implements WebApplicationInitializer
Note: (2) are two classes, one for extension and the other for implementation
I am using (2) because I have found many examples where I am able to configure converters, formatters, resources handlers etc…
But in the latest days I have tried to help a question on StackOverflow and I did realize (1) exists.. I did some overview on Google about (1) and exists some examples working with (1)
My question is how the title of this post describe.
Thank You
With the release of the Servlet 3.0 spec it became possible to configure your Servlet Container with (almost) no xml. For this there is the ServletContainerInitializer in the Servlet specification. In this class you can register filters, listeners, servlets etc. as you would traditionally do in a web.xml.
Spring provides a an implementation the SpringServletContainerInitializer which knows how to handle WebApplicationInitializer classes. Spring also provides a couple of base classes to extend to make your life easier and the AbstractAnnotationConfigDispatcherServletInitializer is one of those. It registers
a ContextLoaderlistener (optionally) and a DispatcherServlet and allows you to easily add configuration classes to load for both classes and to apply filters to the DispatcherServlet and to provide the servlet mapping.
The WebMvcConfigurerAdapter is for configuring Spring MVC, the replacement of the xml file loaded by the DispatcherServlet for configuring Spring MVC. The WebMvcConfigurerAdapter should be used for a #Configuration class.
#Configuration
#EnableWebMvc
public class WebConfiguration
extends WebMvcConfigurerAdapter implements WebApplicationInitializer
{ ... }
I wouldn't recommend mixing those as they are basically 2 different concerns. The first is for configuring the servlet container, the latter for configuring Spring MVC.
You would want to split those into 2 classes.
For the configuration.
#Configuration
#EnableWebMvc
public class WebConfiguration extends WebMvcConfigurerAdapter { ... }
For bootstrapping the application.
public class MyWebApplicationInitializer
extends AbstractAnnotationConfigDispatcherServletInitializer
{
protected Class<?>[] getRootConfigClasses() {
return new Class[] {RootConfig.class};
}
protected Class<?>[] getServletConfigClasses() {
return new Class[] {WebConfiguration .class};
}
protected String[] getServletMappings() {
return new String[] {"/"};
}
}
An added advantage is that you now can use the convenience classes provided by Spring instead of manually configuring the DispatcherServlet and/or ContextLoaderListener.
To start from the beginning it is worth looking into how servlet container starts.
SpringServletContainerInitializer is bootstrapped automatically by any Servlet 3.0 container.
SpringServletContainerInitializer looks for classes implementing WebApplicationInitializer (link to spring.io; also well described in "Spring In Action" 4th edition by Craig Walls, p.135).
So to start - SpringServletContainerInitializer has to find the right class implementing WebApplicationInitializer. There are two ways of making it happen:
One is by implementing WebApplicationInitializer on its own; the interface was introduced in Spring 3.1
The second is by extending AbstractAnnotationConfigDispatcherServletInitializer class which also implements WebApplicationInitializer. The class was introduced in Spring 3.2 for convenience and it is "the preferred approach for applications that use Java-based Spring configuration." - see the link. It enables you to start servlet application context as well as root application context.
I would also like to higlight that WebMvcConfigurerAdapter you mention should not be confused with WebApplicationInitializer. As it name suggests - it has to do with configuring "Mvc". It is an adapter class that implements empty methods from WebMvcConfigurer. You use it when you configure your Mvc controller with #EnableWebMvc annotation.
Hope this helps.

Spring: how AnnotationConfigWebApplicationContext could not overwrite later beans?

I have a web application that use Sring IoC framework.
I use the Java configuration for Spring, and I only use #Configuration annoted module definition (no DI related tags elsewhere in the code).
The Spring registry is built on web application start-up thanks to (a bit modified version of) Spring context loader listener, and the contextConfigLocation param in web.xml configured to point to the #Configuration annotated class.
All that is good and I get a AnnotationConfigWebApplicationContext.
Now, I want to have plugins in my application, that will have their own #Configuration annotated configuration classes, and will use some of the main application services. BUT I don't want to have main application to be modified to load these new modules.
So, I thought that I could simply use the package searching of annotated class for that, but now, it seems that I can use two beans with the same type, even if they have different ids, and clearly AnnotationConfigWebApplicationContext doc states that:
Note: In case of multiple #Configuration classes, later #Bean definitions will override ones defined in earlier loaded files. This can be leveraged to deliberately override certain bean definitions via an extra Configuration class.
I don't want that, because modules should be able to contribute alternative version of services, not (alwways) override existing one - especcially if I want to have a "moduleDef" bean.
I tried to use differents approach on that, but the hierachy of Context and related services is just to big for me.
So, does anybody know how I could reach my goal ?
Thanks
You can have multiple beans of the same type, but You cannot have 2 or more beans with the same ID in a single Spring ApplicationContext - no matter if You use XML or JavaConfig.
The overriding mechanism matches the bean ID's, so all You need to do is to ensure unique ID, i.e.: coreModuleDef, someOtherModuleDef, anotherModuleDef. I don't think You need the ID of each module definition to be identical? What should be sufficient is the type to be the same, but not ID.
You can also turn off the overriding mechanism by setting allowBeanDefinitionOverriding to false on Your AnnotationConfigWebApplicationContext to get an exception if You accidentally override a bean:
public class MyDispatcherServlet extends DispatcherServlet {
#Override
protected void postProcessWebApplicationContext(
ConfigurableWebApplicationContext wac) {
((AnnotationConfigWebApplicationContext) wac)
.setAllowBeanDefinitionOverriding(false);
}
}
or:
public class MyContextLoaderListener extends ContextLoaderListener {
#Override
protected void customizeContext(
ServletContext servletContext,
ConfigurableWebApplicationContext applicationContext) {
((AnnotationConfigWebApplicationContext) wac)
.setAllowBeanDefinitionOverriding(false);
}
}

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