Welcome!

Java IoT Authors: Liz McMillan, Stackify Blog, Elizabeth White, Pat Romanski, Derek Weeks

Related Topics: Java IoT, IBM Cloud

Java IoT: Article

How to Create Secure Web Applications with Struts

Imagine building a house starting with only a pile of timber and a lump of iron

Imagine building a house starting with only a pile of timber and a lump of iron, or making a bowl of spaghetti from a sack of wheat and a bag of tomatoes. The importance of having the right materials makes the idea of building products from scratch seem absurd. Similarly, any software project that doesn't take advantage of the numerous frameworks available for any manner of development activity could be wasting valuable resources and ignoring established best practices.

The advantages of using frameworks are obvious to any developer who has implemented a complex, bug-ridden solution to a design problem that's already been elegantly addressed by a framework. And perhaps the most difficult design problems to get right are those concerning security. With the popularity of Web applications and services on the rise, there has been an increasing move to standardize security-critical tasks, such as authentication and session management, in the container or framework. This way, developers can focus on implementing business processes, rather than specialized tasks like cryptographic algorithms or pseudo-random number generation.

This article will focus on developing secure Web applications with the popular Java framework Struts. It will detail a set of best practices using the included security mechanisms. The first section will provide an overview of both Struts and Web application security as a context for discussion. Each subsequent section will focus on a specific security principle and discuss how Struts can be leveraged to address it.

Struts
Struts is a very popular framework for Java Web applications large and small because of the numerous advantages it offers developers. The main goal of the Struts framework is to enforce a MVC-style (Model-View-Controller) architecture, which means that there is a separation of concerns among different architectural components: the model is the representation of the logic, the view is in charge of displaying data to the user, and the controller is responsible for providing the user with a way to interact with the application and affect the model. A simple analogy for this is a video game, where you have a game console (the model), the television or monitor (the view), and a controller (quite appropriately, the controller). This architectural pattern promotes reuse and stability by reducing the effects of code changes (since the implementation of each component is agnostic to the implementation of the others and the model is isolated from the user).

Although it is approximately an implementation of the MVC pattern, Struts is more accurately based on the "Model 2" architecture specific to the Java servlet technology. Rather than having users access the JSPs directly, Struts applications have a "front controller" servlet that's the initial target of all requests and decides how to process requests and route users. Struts also has two different frameworks, the original (Struts Action Framework) and one based on JSF (Struts Shale). For the purposes of this article, we'll only consider the original framework.

Web Application Security
Web applications (such as those built on Struts) rely on users being able to access potentially sensitive information from all over the world over disparate untrusted networks. It's not exactly a surprise or a secret that many non-secure Web applications have been exploited, making front-page news and causing an enormous amount of problems for the organizations responsible. Application security attacks like SQL injection, cross-site scripting, session hijacking, and cookie poisoning are now mainstays in the toolkit of any hacker worth his salt, and it's becoming increasingly obvious that developers have to put more of an emphasis on security.

Organizations like OWASP (Open Web Application Security Project) and WASC (Web Application Security Consortium) have assembled a great deal of information on how to avoid common pitfalls and create more secure Web applications. These and other resources are invaluable for learning about Web application security, and this article complements them as a guide for best practices in Struts applications with respect to security. Here we'll focus on four specific types of security concerns and how they relate to Struts.

Struts & Input Validation
Input validation refers to the practice of verifying that input from an untrusted source is acceptable and safe to use. This has a significant security impact because malformed data submitted by a malicious user is the direct cause of numerous exploits (including SQL injection and cross-site scripting) and generally causes an application to behave unexpectedly and outside of its security design.

The Struts Validator plug-in lets you cleanly encapsulate all of your validation logic in XML configuration files instead of Java code. The Validator plug-in assists developers by standardizing common types of validations, preventing validation logic duplication, and being easier to verify and change (no recompilation is required). Two things to consider when using the Validator plug-in:

  1. There's a mechanism to validate the code of the ActionForm (org.apache.struts.action.ActionForm, the Java class in the controller responsible for handling user data). However, this doesn't offer the advantages described above and won't be discussed here.
  2. Any business-level validation should be performed in the model, and the controller should be limited to semantic validation (correct length, type, acceptable character set). For instance, in the Validator plug-in you might ensure a credit card number is the right format, but you'd ensure it's a valid card in the business logic.
Here's how the Validator plug-in works:

1.  User input is encapsulated in one of the ValidatorForm classes (which extend ActionForm classes):

public class UserValidatorForm extends org.apache.struts.validator.ValidatorForm {
      public String firstName;
      public String lastName;
      public String phoneNumber;
      public String userId;
      ...
}

2.  Validation functions (several standard ones come pre-baked) are defined in validator-rules.xml. This rule calls a validation method from a custom class:

<validator name="userId"
classname="com.jdjexample.validator.UserIdValidator"
method="validateUserId"
      methodParams="java.lang.Object,
      org.apache.commons.validator.ValidatorAction,
      org.apache.commons.validator.Field,
      org.apache.struts.action.ActionErrors,
      javax.servlet.http.HttpServletRequest"
    msg="errors.userid">
...
</validator>

3.  Validation.xml maps which fields have to be validated by which rules:

<form-validation>
  <formset>
     <form name="userForm">
       <field property="firstName" depends="required">
        <arg0 key="firstName.displayName"/>
      </field>
       <field property="lastName" depends="required ">
         <arg0 key="lastName.displayName"/>
       </field>
<field property="phoneNumber" depends="required, mask">
<arg0 key="phoneNumber.mask"/>
<var>
     <var-name>mask</var-name>
     <var-value>
     ^\D?(\d{3})\D?\D?(\d{3})\D?(\d{4})$
     </var-value>
</var>
</field>
</field>
     <field property="userId" depends="required, userId">
     <arg0 key="phoneNumber.mask"/>
     </field>
    </form>
   </formset>
</form-validation>

More Stories By Alex Smolen

Alex Smolen is a Software Security Consultant at Foundstone, where he provides security consulting services to clients to help find, fix, and prevent security vulnerabilities in enterprise software. His duties include threat modeling, code review, penetration testing and secure software development lifecycle (S-SDLC) design and implementation. Alex’s speaking engagements include Enterprise Architect Summit 2005 where he spoke on emerging trends in enterprise security as well as Better Software Conference 2005. Alex graduated from the University of California, Berkeley, with a BS in electrical engineering and computer science.

Comments (2) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


Most Recent Comments
SYS-CON Belgium News Desk 03/19/06 01:48:20 PM EST

Imagine building a house starting with only a pile of timber and a lump of iron, or making a bowl of spaghetti from a sack of wheat and a bag of tomatoes. The importance of having the right materials makes the idea of building products from scratch seem absurd. Similarly, any software project that doesn't take advantage of the numerous frameworks available for any manner of development activity could be wasting valuable resources and ignoring established best practices.

SYS-CON India News Desk 03/19/06 10:15:48 AM EST

Imagine building a house starting with only a pile of timber and a lump of iron, or making a bowl of spaghetti from a sack of wheat and a bag of tomatoes. The importance of having the right materials makes the idea of building products from scratch seem absurd. Similarly, any software project that doesn't take advantage of the numerous frameworks available for any manner of development activity could be wasting valuable resources and ignoring established best practices.

@ThingsExpo Stories
In his session at @ThingsExpo, Arvind Radhakrishnen discussed how IoT offers new business models in banking and financial services organizations with the capability to revolutionize products, payments, channels, business processes and asset management built on strong architectural foundation. The following topics were covered: How IoT stands to impact various business parameters including customer experience, cost and risk management within BFS organizations.
Internet of @ThingsExpo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 21st Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devic...
The question before companies today is not whether to become intelligent, it’s a question of how and how fast. The key is to adopt and deploy an intelligent application strategy while simultaneously preparing to scale that intelligence. In her session at 21st Cloud Expo, Sangeeta Chakraborty, Chief Customer Officer at Ayasdi, will provide a tactical framework to become a truly intelligent enterprise, including how to identify the right applications for AI, how to build a Center of Excellence to ...
SYS-CON Events announced today that Elastifile will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Elastifile Cloud File System (ECFS) is software-defined data infrastructure designed for seamless and efficient management of dynamic workloads across heterogeneous environments. Elastifile provides the architecture needed to optimize your hybrid cloud environment, by facilitating efficient...
There is only one world-class Cloud event on earth, and that is Cloud Expo – which returns to Silicon Valley for the 21st Cloud Expo at the Santa Clara Convention Center, October 31 - November 2, 2017. Every Global 2000 enterprise in the world is now integrating cloud computing in some form into its IT development and operations. Midsize and small businesses are also migrating to the cloud in increasing numbers. Companies are each developing their unique mix of cloud technologies and service...
SYS-CON Events announced today that Golden Gate University will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Since 1901, non-profit Golden Gate University (GGU) has been helping adults achieve their professional goals by providing high quality, practice-based undergraduate and graduate educational programs in law, taxation, business and related professions. Many of its courses are taug...
SYS-CON Events announced today that Grape Up will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct. 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Grape Up is a software company specializing in cloud native application development and professional services related to Cloud Foundry PaaS. With five expert teams that operate in various sectors of the market across the U.S. and Europe, Grape Up works with a variety of customers from emergi...
SYS-CON Events announced today that DXWorldExpo has been named “Global Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Digital Transformation is the key issue driving the global enterprise IT business. Digital Transformation is most prominent among Global 2000 enterprises and government institutions.
From 2013, NTT Communications has been providing cPaaS service, SkyWay. Its customer’s expectations for leveraging WebRTC technology are not only typical real-time communication use cases such as Web conference, remote education, but also IoT use cases such as remote camera monitoring, smart-glass, and robotic. Because of this, NTT Communications has numerous IoT business use-cases that its customers are developing on top of PaaS. WebRTC will lead IoT businesses to be more innovative and address...
21st International Cloud Expo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy. Me...
Recently, WebRTC has a lot of eyes from market. The use cases of WebRTC are expanding - video chat, online education, online health care etc. Not only for human-to-human communication, but also IoT use cases such as machine to human use cases can be seen recently. One of the typical use-case is remote camera monitoring. With WebRTC, people can have interoperability and flexibility for deploying monitoring service. However, the benefit of WebRTC for IoT is not only its convenience and interopera...
When shopping for a new data processing platform for IoT solutions, many development teams want to be able to test-drive options before making a choice. Yet when evaluating an IoT solution, it’s simply not feasible to do so at scale with physical devices. Building a sensor simulator is the next best choice; however, generating a realistic simulation at very high TPS with ease of configurability is a formidable challenge. When dealing with multiple application or transport protocols, you would be...
SYS-CON Events announced today that Secure Channels, a cybersecurity firm, will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Secure Channels, Inc. offers several products and solutions to its many clients, helping them protect critical data from being compromised and access to computer networks from the unauthorized. The company develops comprehensive data encryption security strategie...
An increasing number of companies are creating products that combine data with analytical capabilities. Running interactive queries on Big Data requires complex architectures to store and query data effectively, typically involving data streams, an choosing efficient file format/database and multiple independent systems that are tied together through custom-engineered pipelines. In his session at @BigDataExpo at @ThingsExpo, Tomer Levi, a senior software engineer at Intel’s Advanced Analytics ...
WebRTC is great technology to build your own communication tools. It will be even more exciting experience it with advanced devices, such as a 360 Camera, 360 microphone, and a depth sensor camera. In his session at @ThingsExpo, Masashi Ganeko, a manager at INFOCOM Corporation, will introduce two experimental projects from his team and what they learned from them. "Shotoku Tamago" uses the robot audition software HARK to track speakers in 360 video of a remote party. "Virtual Teleport" uses a...
SYS-CON Events announced today that App2Cloud will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct. 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. App2Cloud is an online Platform, specializing in migrating legacy applications to any Cloud Providers (AWS, Azure, Google Cloud).
When shopping for a new data processing platform for IoT solutions, many development teams want to be able to test-drive options before making a choice. Yet when evaluating an IoT solution, it’s simply not feasible to do so at scale with physical devices. Building a sensor simulator is the next best choice; however, generating a realistic simulation at very high TPS with ease of configurability is a formidable challenge. When dealing with multiple application or transport protocols, you would be...
Internet-of-Things discussions can end up either going down the consumer gadget rabbit hole or focused on the sort of data logging that industrial manufacturers have been doing forever. However, in fact, companies today are already using IoT data both to optimize their operational technology and to improve the experience of customer interactions in novel ways. In his session at @ThingsExpo, Gordon Haff, Red Hat Technology Evangelist, shared examples from a wide range of industries – including en...
Detecting internal user threats in the Big Data eco-system is challenging and cumbersome. Many organizations monitor internal usage of the Big Data eco-system using a set of alerts. This is not a scalable process given the increase in the number of alerts with the accelerating growth in data volume and user base. Organizations are increasingly leveraging machine learning to monitor only those data elements that are sensitive and critical, autonomously establish monitoring policies, and to detect...
To get the most out of their data, successful companies are not focusing on queries and data lakes, they are actively integrating analytics into their operations with a data-first application development approach. Real-time adjustments to improve revenues, reduce costs, or mitigate risk rely on applications that minimize latency on a variety of data sources. Jack Norris reviews best practices to show how companies develop, deploy, and dynamically update these applications and how this data-first...