Spring Security Form Login

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1. Introduction

This article is going to focus on Login with Spring Security. We’re going to built on top of the simple previous Spring MVC example, as that’s a necessary part of setting up the web application along with the login mechanism.

2. The Maven Dependencies

To add Maven dependencies to the project, please see the Spring Security with Maven article. Both standard spring-security-web and spring-security-config will be required.

3. The web.xml

The Spring Security configuration in the web.xml is simple – only an additional filter added to the standard Spring MVC web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns="http://java.sun.com/xml/ns/javaee" 
   xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
   xsi:schemaLocation="
      http://java.sun.com/xml/ns/javaee 
      http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" 
   id="WebApp_ID" version="3.0">

   <display-name>Spring Secured Application</display-name>

   <!-- Spring MVC -->
   <servlet>
      <servlet-name>mvc</servlet-name>
      <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
      <load-on-startup>1</load-on-startup>
   </servlet>
   <servlet-mapping>
      <servlet-name>mvc</servlet-name>
      <url-pattern>/</url-pattern>
   </servlet-mapping>

   <context-param>
      <param-name>contextClass</param-name>
      <param-value>
         org.springframework.web.context.support.AnnotationConfigWebApplicationContext
      </param-value>
   </context-param>
   <context-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>org.baeldung.spring.web.config</param-value>
   </context-param>
   <listener>
      <listener-class>
         org.springframework.web.context.ContextLoaderListener
      </listener-class>
   </listener>

   <!-- Spring Security -->
   <filter>
      <filter-name>springSecurityFilterChain</filter-name>
      <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
   </filter>
   <filter-mapping>
      <filter-name>springSecurityFilterChain</filter-name>
      <url-pattern>/*</url-pattern>
   </filter-mapping>

</web-app>

The filter – DelegatingFilterProxy – simply delegates to a Spring managed bean – the FilterChainProxy – which itself is able to benefit from full Spring bean lifecycle management and such.

4. The Spring Security configuration

The Spring configuration is mostly written in Java, but Spring Security configuration doesn’t yet support full Java and still needs to be XML for the most part. There is an ongoing effort to add Java based configuration for Spring Security, but this is not yet mature.

The overall project is using Java configuration, so the XML configuration file needs to be imported via a Java @Configuration class:

@Configuration
@ImportResource({ "classpath:webSecurityConfig.xml" })
public class SecSecurityConfig {
   public SecSecurityConfig() {
      super();
   }
}

The Spring Security XML Configuration – webSecurityConfig.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/security" 
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:beans="http://www.springframework.org/schema/beans"
  xsi:schemaLocation="
      http://www.springframework.org/schema/security 
      http://www.springframework.org/schema/security/spring-security-4.0.xsd
      http://www.springframework.org/schema/beans 
      http://www.springframework.org/schema/beans/spring-beans-4.2.xsd">

   <http use-expressions="true">
      <intercept-url pattern="/login*" access="isAnonymous()" />
      <intercept-url pattern="/**" access="isAuthenticated()"/>

      <form-login 
         login-page='/login.html' 
         default-target-url="/homepage.html" 
         authentication-failure-url="/login.html?error=true" />

      <logout logout-success-url="/login.html" />

   </http>
   <authentication-manager>
      <authentication-provider>
         <user-service>
            <user name="user1" password="user1Pass" authorities="ROLE_USER" />
         </user-service>
      </authentication-provider>
   </authentication-manager>
</beans:beans>

5.1. <intercept-url>

We are allowing anonymous access on /login so that users can authenticate. We are also securing everything else.

Note that the order of the <intercept-url> element is significant – the more specific rules need to come first, followed by the more general ones.

5.2. <form-login>

  • login-page – the custom login page
  • default-target-url – the landing page after a successful login
  • authentication-failure-url – the landing page after an unsuccessful login

5.3. <authentication-manager>

The Authentication Provider is backed by a simple, in-memory implementation – InMemoryUserDetailsManager specifically – configured in plain text. This only exists in Spring 3.1 and above and is meant to be used for rapid prototyping when a full persistence mechanism is not yet necessary.

6. The Login Form

The login form page is going to be registered with Spring MVC using the straightforward mechanism to map views names to URLs with no need for an explicit controller in between:

   registry.addViewController("/login.html");

This of course corresponds to the login.jsp:

<html>
<head></head>
<body>
   <h1>Login</h1>
   <form name='f' action="login" method='POST'>
      <table>
         <tr>
            <td>User:</td>
            <td><input type='text' name='username' value=''></td>
         </tr>
         <tr>
            <td>Password:</td>
            <td><input type='password' name='password' /></td>
         </tr>
         <tr>
            <td><input name="submit" type="submit" value="submit" /></td>
         </tr>
      </table>
  </form>
</body>
</html>

The Spring Login form has the following relevant artifacts:

  • login – the URL where the form is POSTed to trigger the authentication process
  • username – the user name
  • password – the password

7. Further Configuring Spring Login

We briefly discussed a few configurations of the login mechanism when we introduced the Spring Security XML Configuration above – let’s go into some detail now.

One reason to override most of the defaults in Spring Security is to hide the fact that the application is secured with Spring Security and minimize the information a potential attacker knows about the application.

Fully configured, the <form-login> element looks like this:

<form-login 
   login-page='/login.html' 
   login-processing-url="/perform_login" 
   default-target-url="/homepage.html"
   authentication-failure-url="/login.html?error=true" 
   always-use-default-target="true"/>

7.1. The Login page

The custom login page is configured via the login-page attribute on <form-login>:

login-page='/login.html'

If this is not specified, a default URL is used – spring_security_login – and Spring Security will generate a very basic Login Form at that URL.

7.2. The POST URL for Login

The default URL where the Spring Login will POST to trigger the authentication process is /login which used to be /j_spring_security_check before Spring Security 4.

This URL can be overridden via the login-processing-url attribute on <form-login>:

login-processing-url="/perform_login"

A good reason to override this default URL is to hide the fact that the application is actually secured with Spring Security – that information should not be available externally.

7.3. The Landing page on Success

After a successful Login process, the user is redirected to a page – which by default is the root of the web application.

This can be overridden via the default-target-url attribute on <form-login>:

default-target-url="/homepage.html"

In case the always-use-default-target is set to true, then the user is always redirected to this page. If that attribute is set to false, then the user will be redirected to the previous page they wanted to visit before being promoted to authenticate.

7.3. The Landing page on Failure

Same as with the Login Page, the Login Failure Page is autogenerated by Spring Security at /spring_security_login?login_error by default.

This can be overridden via the authentication-failure-url attribute on <form-login>:

authentication-failure-url="/login.html?error=true"

8. Conclusion

In this Spring Login Example we configured a simple authentication process – we discussed the Spring Security Login Form, the Security XML Configuration and some of the more advanced customizations available in the namespace.

The implementation of this Spring Login tutorial can be found in the github project – this is an Eclipse based project, so it should be easy to import and run as it is.

When the project runs locally, the sample html can be accessed at:

 http://localhost:8080/spring-security-login/login.html

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>> CHECK OUT THE COURSE

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,

  • Hitesh Lad

    Thanks for the conciseness of this post. I’ve added spring security to a new project with ease. Also thanks for that separate post RE: the maven dependencies. That was the icing on the cake

  • mbeddedsoft

    Hello, nice article. Very informative and helpful as usual. Question, I have a Spring 4 MVC web application configured with Spring Security. I’ve got login working using both the standard login form and a REST Service. The problem I have is, users are allowed to ‘view’ certain content anonymously. If they choose to log in, the can do this through the menu login option which is backed by a REST Service. The issue i have is, when users login through the menu option, they are automatically taken to the home page. Even though I already removed the ‘default-target-url’ property from the element in spring security.

    Here’s the snippet for my configuration in dev environment.

    Do you see any reason why logging in using the REST Service would redirect the user to the homepage?

    thanks,
    mbeddedsoft

    • http://www.baeldung.com/ Eugen Paraschiv

      That’s an interesting question. It’s also a very information-rich question – and there’s a whole lot to unpack here – so I won’t hit on everything.
      First, let’s take a step back. An MVC style application is very different than a REST API – and the authentication process is significantly different as well. For instance, in an MVC style app, you may want the redirect, whereas in an API, you most likely don’t.
      And all of that is conveniently glossing over questions like – statelessness of the API and does the standard, cookie-based authentication fit into that – questions I would definitely recommend you explore, because they’re instrumental for how your system is designed.
      Now – to cut to the practical bit – here’s a writeup that shows you how to set Spring Security up so that it doesn’t redirect and returns a 200 OK instead.
      Hope it helps. Cheers,
      Eugen.

      • mbeddedsoft

        Thank you Eugen!

        • http://www.baeldung.com/ Eugen Paraschiv

          Sure thing, glad to help. Cheers,
          Eugen.

  • sabrin

    Thank you for those interesting series. They help a lot. I have question for you, actually I implements authentication for sso with spring security saml, and now I need to active this authentication if I have special param in my request and if not use simple authentication form. If you have any idea I will be grateful.

    • http://www.baeldung.com/ Eugen Paraschiv

      Hey Sabrin – you should be able to define multiple authentication providers. These should execute in order, and so you’ll have multiple opportunities to authenticate the user based on whatever is the deciding factor in that process.
      Hope that helps. Cheers,
      Eugen.

      • sabrin

        Hey, the problem is that for each type of authentication I need to display specific login page.

        • http://www.baeldung.com/ Eugen Paraschiv

          OK, but based on what. What’s the deciding factor that the application is using when it decides which login page to show?

          • sabrin

            Thank you for replying. We could say that depends on parameter in request header.

          • http://www.baeldung.com/ Eugen Paraschiv

            The way to go here would be trying to use multiple entry points, via multiple elements. Hope that helps. Cheers,
            Eugen.