Click here to close now.

Welcome!

Java Authors: Pat Romanski, Liz McMillan, Elizabeth White, Carmen Gonzalez, Plutora Blog

Related Topics: Java

Java: Article

Using Self-Signed Certificates for Web Service Security

How to compete with trusted certificate authorities

One of the great things about the Java programming language is the Open Source community that provides great applications at little or no cost. An example of this is Apache Tomcat, which provides a solid Web server for development using servlet or JSP technology. Now that Web Service technology is maturing there's a potential for a whole scenario of applications to take advantage of a Swing feature-rich thin client on the front-end coupled to the data verification and business logic already developed in the Web or ejb tier. Such applications are only viable if they can be secure, however, security doesn't have to come at a great cost. The purpose of this article is to demonstrate how Web Service clients can use self-signed security certificates over the secure HTTPS protocol.

The Problem with Using Self-Signed Certificates
HTTPS typically works seamlessly with the non-secure HTTP protocol and doesn't interrupt the user's experience. This is because SSL certificates are designed to be verified and signed by a trusted third party. Verisign is a popular certificate authority. If a Web application requires secure communication, you can pay Verisign to sign your SSL certificate. Once Verisign does that, users on your Web site can switch between HTTP and HTTPS without interruption because all major Web browsers trust certificates signed by Verisign. Verisign is not the only option for getting certificates signed. To save operating costs, or for personal use, you can self-sign your own certificate. However, self-signing your certificate will interrupt your Web site user's experience. Typically the Web browser will display a dialog box asking if you want to trust a certificate you signed.

Web browsers are nice because when they get a certificate signed by an unknown certificate authority there's an option to proceed. When developing Web Service clients for communication over HTTPS it's not so easy. When running Java code there's no dialog box asking about trusting a distrusted certificate authority. The JRE will throw an exception trying to connect over HTTPS to a Web site with a distrusted certificate:

Caused by: sun.security.validator.ValidatorException: No trusted certificate found

There's no way to catch this exception and continue. To get the Web Service to work with a self-signed certificate the JRE has to somehow trust you as a certificate authority.

Solution Outline
To demonstrate a solution to this problem I'll do the following:

  1. Generate and self-sign my own certificate
  2. Configure Tomcat for SSL and make it use that certificate
  3. Create an example Web Service to be called over HTTPS
  4. Generate Web Service client code from WSDL
  5. Demonstrate a client using a custom keystore solution
Generating a Self-Signed Certificate
The JDK comes with a tool, keytool.exe, that is used to mange SSL public/private keys. Keys are added and removed from a binary file on the file system. The default keystore file is JAVA_HOME\jre\lib\security\cacerts. This file contains the list of certificate authorities that the JRE will trust. A list of well-known trusted companies like Verisign is already in the keystore. To see this list, execute with password "changeit":

D:\>keytool -list -rfc -keystore JAVA_HOME\jre\lib\security\cacerts

The keytool application can be used to edit this file. However, just in case something goes wrong it's better to create a new file. If keytool isn't told which file to use it creates HOME/.keystore by default.

To generate your own self-signed certificate execute:

D:\>keytool.exe -genkey -alias Tomcat -keyalg RSA -storepass bigsecret -keypass bigsecret -dname "cn=localhost"

After executing this command there will be a .keystore file in your HOME directory. Here's what the switches mean.

  • genkey: Tells the keytool applica-tion to generate new public/private key pair.
  • alias: The name used to refer to the keys. Remember, the .keystore file can contain many keys.
  • keyalg: Generates public/private keys using the RSA algorithm.
  • storepass: What password is needed to access the .keystore file.
  • keypass: What password is needed to manage the keys.
  • dname: This value is very important. I used "localhost" because this example is designed to run locally. If a Web application is registered as http://www.myserver.com then this value must be www.myserver.com. If the names don't match the certificate will automatically be rejected.
Once the keytool application creates a new public/private key pair it automatically self-signs the key. You have just generated your own self-signed certificate, which can be used for HTTPS communications. You only need to extract the self-signed public key. I'll show how to do this later.

Configuring Tomcat for SSL
Now you have to configure Tomcat to use your self-signed certificate. I used Tomcat 5.0.30. Edit the TOMCAT/conf/server.xml file. Search the file for "8443" and uncomment the <Connector.../> bound to that port. Then you'll have to add the following property to the <Connector.../>:

keystorePass="bigsecret"

When the JRE starts, it will automatically find the HOME/.keystore file and Tomcat will try to access it using the password "bigsecret." When Tomcat starts there should be output to the console that looks similar to:

Feb 4, 2006 3:11:23 PM org.apache.coyote.http11.Http11Protocol start
INFO: Starting Coyote HTTP/1.1 on http-8443

This means the <Connector.../> successfully read the .keystore file and you can now do secure HTTPS connections over the 8443 port. Open a Web browser and try https://localhost:8443/. Because the certificate is self-signed the Web browser will display a dialog box asking about trusting the connection. If accepted, all communications will be secure over HTTPS.

Creating the Web Service
I'm going to use the Apache Axis project to create a very simple Web Service. The Web Service will simulate checking for new e-mail messages. A Web Service client passes a token uniquely identifying a user. The Web Service returns a list of new e-mail messages (see Listing 1).

To get the Web Service deployed, follow these steps:

  1. Cut and paste the code from Listing 1 into a file named Email.jws in Webapp's root directory.
  2. Edit the Web.xml file, adding the Axis servlet and a *.jws mapping (Listing 2).
  3. Put the Axis jar files in WEB-INF/lib. See References at the end of this article for the Axis project URL.
After deploying this article's accompanying WAR file (and configuring Tomcat for SSL), the Web Service is accessible securely over HTTPS at the following URL:

https://localhost:8443/JDJArticleWebService/Email.jws

Using WSDL2Java
The Axis project provides a tool named WSDL2Java that takes a Web Service WSDL and automatically create the Java source code needed to use the Web Service. See Listing 3 for the command line used to generate code for the Email.jws Web Service.

Notice the URL in Listing 3 used to access the WSDL. It's the non-secure HTTP protocol over port 8080. Why not use HTTPS over port 8443? Because of the self-signed certificate, the WSDL2Java tool will encounter the same exact certificate problem this article is trying to provide a solution for. So for now the non-secure protocol must be used. This means the generated code must be altered slightly replacing "http" and "8080" references with "https" and "8443." This article's accompanying client zip file contains the altered code.

Client with a Custom Keystore
The JRE's default keystore is JAVA_HOME\jre\lib\security\cacerts. Java applications will throw an exception whenever they are presented with your self-signed certificate because your certificate isn't in this keystore. Therefore, when developing a client there are two options. The first option is to put your self-signed certificate into the JRE's default keystore. Although this would work it's not a very good solution because customization is required on every client machine. The second option is to generate a custom keystore, put your self-signed certificate into it, and distribute the custom keystore as part of your application (typically inside a jar file).

To create a custom keystore for your client the following has to be done:

  1. Export the self-signed public key from HOME/.keystore.
  2. Import the self-signed public key into a new keystore for you client.
To export the self-signed public key from HOME/.keystore execute the following:

D:\>keytool.exe -export -rfc -alias Tomcat -file Tomcat.cer -storepass bigsecret -keypass bigsecret

Now create the custom keystore for the client by importing Tomcat.cer:

D:>keytool.exe -import -noprompt -trustcacerts -alias Tomcat -file Tomcat.cer -keystore CustomKeystore -storepass littlesecret

Using the switch "-keystore CustomKeystore" will create a new keystore file called "CustomKeystore" in the present working directory. You'll find the CustomKeystore file in the /classpath/resources/keystore directory of this article's client zip file. Replace this one with the file just generated.

Now all that's left to do is to create a client that uses this custom keystore. I'll demonstrate two ways to do this.

The first is to use the Java system properties javax.net.ssl.trustStore and javax.net.ssl.trustStorePassword to point to the CustomKeystore file and provide the password to access it. My example Web Service client in the jdj.wsclient.truststore package takes this approach (see Listing 4). The main() method sets the system properties then creates the objects to use the Web Service. When the JRE needs to access a keystore it looks for the "classpath/resources/keystore/CustomKeystore" file on the file system. Although this is a simple solution it's problematic because the keystore file must be on the file system and the client code must know where to look for it.

The second is a more portable solution that keeps resources inside the jar file and avoids the file system issues. The client code is responsible for reading the CustomKeystore file and somehow using it to create a secure connection to the server. My example Web Service client in the jdj.wsclient.socketfactory package takes this approach (see Listing 5). Listing 5 shows how to read the CustomKeystore file as a resource and use it to create a javax.net.ssl.SSLSocketFactory. Configuring the Axis pluggable architecture, the MySocketFactory class can be then used to create secure Socket objects from this factory.

Conclusion
This article started with a simple problem: I wanted to secure Web Service communications over HTTPS using my own self-signed certificates. By default, the JRE will reject my application's self-signed certificate because I am not a trusted certificate authority. To get secure communications to work I had to get the Web Service client JRE to trust my self-signed certificate. To achieve this, I used the keytool application and generated a new public/private key pair, extracted the self-signed public key, and then created a new keystore and imported this self-signed certificate. I then created a totally self-contained Web Service client that doesn't require any client-side configuration.

References

More Stories By Michael Remijan

Michael J. Remijan is a research programmer at the National Center for Supercomputing Applicaitons (NCSA). His chief responsibilities include data miming and access to terabyte-sized astronomy data sets. Michael received a BS in mathematics and computer science from the University of Illinois and is currently working on an MBA in technology management.

Comments (5) 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
Devs 07/26/06 03:20:28 PM EDT

Hello,
I read your article. I am trying to use your approach mentioned in Listing 5(putting keytore on the jar file ). How do I go about doing it. I create MySSLFactory using Listing 5. Now what do I have to confiugre in axis. How do I tell axis to use the MySSLFactory.

Thanks
Deval

Faizan Raza 06/21/06 02:46:05 AM EDT

Nice article and very precise.
Helped me a lot in sorting out the problems i had with the self signed certificate.

thanks
Faizan

Philip Rallings 06/18/06 04:15:00 PM EDT

excellent article that explains everyting clearly

Is it possibe to have a cope of the zip file that accompanied the article.

Many Thanks
Phi

Ismael 06/02/06 07:06:48 AM EDT

I have followed your article, it is very clear, congratulations.

But I am having some problems with my testings, I am trying to use your thid approach (putting keytore on the jar file as you detail on listing 5).

I know that I should use MySocketFactory, but the listing code contains only a method, it is not a class.

What should I do:

-Create a class (which interfaces should it implement o which classes to extend). How should I configure Axis to use it.

-Put this method on a class and call it on the startup (code has a reference to factory not solved on the method)

Maybe I should get the default factory (I do not know which method should I use) and set the new one on the code published.

It would be great to have all the complete code used to make the article. This way I could find out how to apply them to my code.

Regards,
Ismael

SYS-CON Media News Desk 05/26/06 10:44:51 AM EDT

One of the great things about the Java programming language is the Open Source community that provides great applications at little or no cost. An example of this is Apache Tomcat, which provides a solid Web server for development using servlet or JSP technology. Now that Web Service technology is maturing there's a potential for a whole scenario of applications to take advantage of a Swing feature-rich thin client on the front-end coupled to the data verification and business logic already developed in the Web or ejb tier. Such applications are only viable if they can be secure, however, security doesn't have to come at a great cost. The purpose of this article is to demonstrate how Web Service clients can use self-signed security certificates over the secure HTTPS protocol.

@ThingsExpo Stories
One of the biggest impacts of the Internet of Things is and will continue to be on data; specifically data volume, management and usage. Companies are scrambling to adapt to this new and unpredictable data reality with legacy infrastructure that cannot handle the speed and volume of data. In his session at @ThingsExpo, Don DeLoach, CEO and president of Infobright, will discuss how companies need to rethink their data infrastructure to participate in the IoT, including: Data storage: Understanding the kinds of data: structured, unstructured, big/small? Analytics: What kinds and how responsiv...
Since 2008 and for the first time in history, more than half of humans live in urban areas, urging cities to become “smart.” Today, cities can leverage the wide availability of smartphones combined with new technologies such as Beacons or NFC to connect their urban furniture and environment to create citizen-first services that improve transportation, way-finding and information delivery. In her session at @ThingsExpo, Laetitia Gazel-Anthoine, CEO of Connecthings, will focus on successful use cases.
The Workspace-as-a-Service (WaaS) market will grow to $6.4B by 2018. In his session at 16th Cloud Expo, Seth Bostock, CEO of IndependenceIT, will begin by walking the audience through the evolution of Workspace as-a-Service, where it is now vs. where it going. To look beyond the desktop we must understand exactly what WaaS is, who the users are, and where it is going in the future. IT departments, ISVs and service providers must look to workflow and automation capabilities to adapt to growing demand and the rapidly changing workspace model.
Sensor-enabled things are becoming more commonplace, precursors to a larger and more complex framework that most consider the ultimate promise of the IoT: things connecting, interacting, sharing, storing, and over time perhaps learning and predicting based on habits, behaviors, location, preferences, purchases and more. In his session at @ThingsExpo, Tom Wesselman, Director of Communications Ecosystem Architecture at Plantronics, will examine the still nascent IoT as it is coalescing, including what it is today, what it might ultimately be, the role of wearable tech, and technology gaps stil...
Almost everyone sees the potential of Internet of Things but how can businesses truly unlock that potential. The key will be in the ability to discover business insight in the midst of an ocean of Big Data generated from billions of embedded devices via Systems of Discover. Businesses will also need to ensure that they can sustain that insight by leveraging the cloud for global reach, scale and elasticity.
The Internet of Things (IoT) promises to evolve the way the world does business; however, understanding how to apply it to your company can be a mystery. Most people struggle with understanding the potential business uses or tend to get caught up in the technology, resulting in solutions that fail to meet even minimum business goals. In his session at @ThingsExpo, Jesse Shiah, CEO / President / Co-Founder of AgilePoint Inc., showed what is needed to leverage the IoT to transform your business. He discussed opportunities and challenges ahead for the IoT from a market and technical point of vie...
IoT is still a vague buzzword for many people. In his session at @ThingsExpo, Mike Kavis, Vice President & Principal Cloud Architect at Cloud Technology Partners, discussed the business value of IoT that goes far beyond the general public's perception that IoT is all about wearables and home consumer services. He also discussed how IoT is perceived by investors and how venture capitalist access this space. Other topics discussed were barriers to success, what is new, what is old, and what the future may hold. Mike Kavis is Vice President & Principal Cloud Architect at Cloud Technology Pa...
Hadoop as a Service (as offered by handful of niche vendors now) is a cloud computing solution that makes medium and large-scale data processing accessible, easy, fast and inexpensive. In his session at Big Data Expo, Kumar Ramamurthy, Vice President and Chief Technologist, EIM & Big Data, at Virtusa, will discuss how this is achieved by eliminating the operational challenges of running Hadoop, so one can focus on business growth. The fragmented Hadoop distribution world and various PaaS solutions that provide a Hadoop flavor either make choices for customers very flexible in the name of opti...
The true value of the Internet of Things (IoT) lies not just in the data, but through the services that protect the data, perform the analysis and present findings in a usable way. With many IoT elements rooted in traditional IT components, Big Data and IoT isn’t just a play for enterprise. In fact, the IoT presents SMBs with the prospect of launching entirely new activities and exploring innovative areas. CompTIA research identifies several areas where IoT is expected to have the greatest impact.
Advanced Persistent Threats (APTs) are increasing at an unprecedented rate. The threat landscape of today is drastically different than just a few years ago. Attacks are much more organized and sophisticated. They are harder to detect and even harder to anticipate. In the foreseeable future it's going to get a whole lot harder. Everything you know today will change. Keeping up with this changing landscape is already a daunting task. Your organization needs to use the latest tools, methods and expertise to guard against those threats. But will that be enough? In the foreseeable future attacks w...
Disruptive macro trends in technology are impacting and dramatically changing the "art of the possible" relative to supply chain management practices through the innovative use of IoT, cloud, machine learning and Big Data to enable connected ecosystems of engagement. Enterprise informatics can now move beyond point solutions that merely monitor the past and implement integrated enterprise fabrics that enable end-to-end supply chain visibility to improve customer service delivery and optimize supplier management. Learn about enterprise architecture strategies for designing connected systems tha...
Dale Kim is the Director of Industry Solutions at MapR. His background includes a variety of technical and management roles at information technology companies. While his experience includes work with relational databases, much of his career pertains to non-relational data in the areas of search, content management, and NoSQL, and includes senior roles in technical marketing, sales engineering, and support engineering. Dale holds an MBA from Santa Clara University, and a BA in Computer Science from the University of California, Berkeley.
Wearable devices have come of age. The primary applications of wearables so far have been "the Quantified Self" or the tracking of one's fitness and health status. We propose the evolution of wearables into social and emotional communication devices. Our BE(tm) sensor uses light to visualize the skin conductance response. Our sensors are very inexpensive and can be massively distributed to audiences or groups of any size, in order to gauge reactions to performances, video, or any kind of presentation. In her session at @ThingsExpo, Jocelyn Scheirer, CEO & Founder of Bionolux, will discuss ho...
The cloud is now a fact of life but generating recurring revenues that are driven by solutions and services on a consumption model have been hard to implement, until now. In their session at 16th Cloud Expo, Ermanno Bonifazi, CEO & Founder of Solgenia, and Ian Khan, Global Strategic Positioning & Brand Manager at Solgenia, will discuss how a top European telco has leveraged the innovative recurring revenue generating capability of the consumption cloud to enable a unique cloud monetization model to drive results.
As organizations shift toward IT-as-a-service models, the need for managing and protecting data residing across physical, virtual, and now cloud environments grows with it. CommVault can ensure protection &E-Discovery of your data – whether in a private cloud, a Service Provider delivered public cloud, or a hybrid cloud environment – across the heterogeneous enterprise. In his session at 16th Cloud Expo, Randy De Meno, Chief Technologist - Windows Products and Microsoft Partnerships, will discuss how to cut costs, scale easily, and unleash insight with CommVault Simpana software, the only si...
Analytics is the foundation of smart data and now, with the ability to run Hadoop directly on smart storage systems like Cloudian HyperStore, enterprises will gain huge business advantages in terms of scalability, efficiency and cost savings as they move closer to realizing the potential of the Internet of Things. In his session at 16th Cloud Expo, Paul Turner, technology evangelist and CMO at Cloudian, Inc., will discuss the revolutionary notion that the storage world is transitioning from mere Big Data to smart data. He will argue that today’s hybrid cloud storage solutions, with commodity...
Every innovation or invention was originally a daydream. You like to imagine a “what-if” scenario. And with all the attention being paid to the so-called Internet of Things (IoT) you don’t have to stretch the imagination too much to see how this may impact commercial and homeowners insurance. We’re beyond the point of accepting this as a leap of faith. The groundwork is laid. Now it’s just a matter of time. We can thank the inventors of smart thermostats for developing a practical business application that everyone can relate to. Gone are the salad days of smart home apps, the early chalkb...
Cloud data governance was previously an avoided function when cloud deployments were relatively small. With the rapid adoption in public cloud – both rogue and sanctioned, it’s not uncommon to find regulated data dumped into public cloud and unprotected. This is why enterprises and cloud providers alike need to embrace a cloud data governance function and map policies, processes and technology controls accordingly. In her session at 15th Cloud Expo, Evelyn de Souza, Data Privacy and Compliance Strategy Leader at Cisco Systems, will focus on how to set up a cloud data governance program and s...
Roberto Medrano, Executive Vice President at SOA Software, had reached 30,000 page views on his home page - http://RobertoMedrano.SYS-CON.com/ - on the SYS-CON family of online magazines, which includes Cloud Computing Journal, Internet of Things Journal, Big Data Journal, and SOA World Magazine. He is a recognized executive in the information technology fields of SOA, internet security, governance, and compliance. He has extensive experience with both start-ups and large companies, having been involved at the beginning of four IT industries: EDA, Open Systems, Computer Security and now SOA.
The industrial software market has treated data with the mentality of “collect everything now, worry about how to use it later.” We now find ourselves buried in data, with the pervasive connectivity of the (Industrial) Internet of Things only piling on more numbers. There’s too much data and not enough information. In his session at @ThingsExpo, Bob Gates, Global Marketing Director, GE’s Intelligent Platforms business, to discuss how realizing the power of IoT, software developers are now focused on understanding how industrial data can create intelligence for industrial operations. Imagine ...