What is good practice to configure Spring MVC application with Spring security? - spring

Assume I have Spring MVC powered application with Spring security. I have:
UserBean class which provides CRUD operations on table User
UserController : controller which expose operation on User to http clients
UserLogin: Authentication provider from Spring security, which authenticates users.
How should I configure my application if:
I want simple XML configuration, with auto-discovering beans by annotations (<context:component-scan base-package="org.example"/>)
UserLogin and UserController needs UserBean to work
UserLogin and UserController use transaction annotations and aspect annotations
I see the following oportunities:
Create one common Spring XML configuration file, used both by DispatcherServlet and ContextLoaderListener
Disadvantage: nobody shows that solution in tutorial. All beans are duplicated (one instance in ContextLoaderListener context, second in DispatcherServlet). Duplication may cause some hard to track bugs. Duplication is not elegant
Create two Spring XML configuration files, one for ContextLoaderListener (main) and one for DispatcherServlet (controllers). UserBean is declared in first config and visible in second one
Disadvantage: to avoid duplication I have to add complex component scanning rules to both files (context:component-scan). <tx:annotation-driven and <aop:aspectj-autoproxy/> must be defined in both files. I will have still doubts which config file is appropiate when declaring new stuff.
Create two Spring XML configuration files and include third for common settings like <tx:annotation-driven
Disadvantage: I wanted simple solution...
Summary: I'm looking for good practice to configure application with Spring MVC + Spring Security AND security part is highly connected with business part. I was searching for good example but I always find case when security code is isolated from business code. But I need example when security and business share the code
Similar question: ContextLoaderListener or not?

I have two xml files for my configuration, no particular reason, that's just how it worked out.
These sample spring security projects provide good examples of lots of different types of configurations maybe you can find something that works for you:
https://github.com/spring-projects/spring-security/tree/master/samples

Hidden message in my question was: having two contexts is stupid.
Did someone already notice that?
Is there a way to have single application configuration?
Answers:
Yes. https://jira.springsource.org/browse/SPR-6903
Yes. https://github.com/michaldo/spring-single-context-demo
The best practice which applies to my case is described here: https://stackoverflow.com/a/14032213/2365727

Related

How to load PropertySources sooner in Spring Boot

I have currently a problem in my DEV environment. I have for Spring Security two configurations, one for the Admin part of my application and the other for the rest of the user. For the admin part, I create one or another depending on beans decorated with a Conditional annotation. This conditionals rely on some property that is loaded from a class that is annotated with #PropertySource and this is important, this property I cannot set it neither in application.properties nor application-<environment>.properties. The problem comes that when these conditionals are evaluated because are spring security classes, the properties that are expected to perform such evaluation are not available, they come in a later stage, when Spring boot do some refresh context. My question is how I can do it do this class annotated with #Configuration #PropertySources to be loaded much sooner, right after the Profile is processed.
Thanks in advance.

Confusion regarding ApplicationContext in Spring MVC

I was referring to Spring configuration related blogs and came across some information on applicationContext. One article it is mentioned:
"In most simple cases, the ApplicationContext(defaule name for file is applicationContext.xml) is unnecessary. It is generally used to contain beans that are shared between all servlets in a webapp. If you only have one servlet, then there's not really much point, unless you have a specific use for it."
Where it is also mentioned:
"If you are not explicitly declaring the context configuration file name in web.xml using the contextConfigLocation param, Spring will search for the applicationContext.xml under WEB-INF folder and throw FileNotFoundException if it could not find this file."
Above two statements seems to be contradicting (though it is not). Can you please help clarifying above or suggests me link that clarifies above points?
From : http://www.tutorialspoint.com/spring/spring_applicationcontext_container.htm
The Application Context is spring's more advanced container.
Similar to BeanFactory it can load bean definitions, wire beans together and dispense beans upon request.
Additionally it adds more enterprise-specific functionality such as the ability to resolve textual messages from a properties file and the ability to publish application events to interested event listeners. This container is defined by the org.springframework.context.ApplicationContext interface.
That means Application Context is a container and it can load beans from xml files and from #Bean annotations from your java code. With recent spring versions you can configure all of your beans in java code and not use xml files.

Register Spring filter from BeanDefinitionParser

I am creating a custom namespace for use in the Spring XML configuration. I already implemented a NamespaceHandler and BeanDefinitionParser. So, now I can just put <myns:some-awesome-feature /> into my Spring configuration and it creates the required beans automatically.
In addition to creating some normal Spring beans I would also like to have this annotation register a OncePerRequestFilter to extract some information off of a request for my code to be able to utilize. Is there a way to register a filter programmatically using the two classes I have available when implementing a custom XML tag?
It is not possible without touching web.xml or WebApplicationInitializer, respectively.
But you can create an extendable solution that allows modifications in future without hassle.
Spring Security's <http pattern='...' security="..."/> automatically creates and registers a series of chained filter beans for you. All you have to do is to
register DelegatingFilterProxy in you web.xml and reference springSecurityFilterChain.
You can create a similar solution where you are defining e.g. <myns:awesome-http pattern='...' /> which instantiates OncePerRequestFilter. In web.xml you are declaring a DelegatingFilterProxy which references your awesomeFilterChain. In a future version you can add more filter to your chain without touching the configuration.
I have never implemented such a feature but I'm quite confident that it is possible.
As a starting point take a look at the source of HttpConfigurationBuilder and HttpSecurityBeanDefinitionParser to see how Spring Security implemented <http .../>.

Hard?: Spring security on classes that are not Spring Beans?

Definitely need some expert help with this! I think this is mainly a Spring Security question, but as I don't know for sure, so I am also tagging with the general Spring tag!
When the Application Context is loaded (mine is all via Java Config, though I don't believe that matters), the "DefaultListableBeanFactory" is processed and eventually (via the ProxyFactory) Spring Security Advisors are added. This is great when I have Spring Beans as I have Permissions that need authorization.
My question is: how do I get the same effect when I no longer require those classes to be Spring Beans? Said differently, if I have an object instance created as a singleton bean via Java Config and the authorization is working correctly, is it possible to maintain that with the object instance being a POJO? Again, for the experts, I want the interception chain returned in the JdkDynamicAopProxy to contain the Spring Security interceptors.
And "no", I am not really expecting an answer to this, maybe just hoping!!!
To add security interceptors to beans not instantiated by spring container
switch global-security tag to mode aspectj and weave the provided AnnotationSecurityAspect in the aspecj module.
For your second question I suppose that you want to do one of the following:
Use a ProxyFactoryBean to secure a bean.
Create security proxies programmatically: Use ProxyFactory.addAdvice() method.
Add the security interceptor to all proxies created by an AutoProxyCreator: This usually don't needed, but you can use the AbstractAutoProxyCreator.interceptorNames property to add common interceptors. The global-security tag parser uses a generated name for the MethodSecurityInterceptor, so you need to configure the interceptor manually and set a consistent SecurityMetadataSource.

spring applicationConfig beans node

In the spring configuration file applicationConfig.xml, the root node is beans.
But it doesn't contain only beans. In fact, security configuration requires an http element.
My question is: while http is not (seems to me not to be) a bean, is it "bean like" in the sense that it determines the creation of a service, or refers to a running service (say the http listener for the application)?
PS. In "Spring Security Reference documentation" 3.1.0-DRAFT at 2.1.1:
"Web/HTTP Security (...) Sets up the filters and related service beans used to apply the framework authentication mechanisms ..."
Yes, everything in a Spring config is just setting up beans. You could--and in fact used to be forced to--set up all the beans yourself, but along about Spring 2.0, the framework added a nifty feature that they called "Extensible XML Authoring", which gives other people/projects a way to define their own, custom XML syntax that gets translated into Spring beans at startup via a NamespaceHandler.

Resources