Welcome!

Microsoft Cloud Authors: Janakiram MSV, Yeshim Deniz, David H Deans, Andreas Grabner, Stackify Blog

Related Topics: Microsoft Cloud

Microsoft Cloud: Article

Securing .NET Compact Framework Solutions

Securing .NET Compact Framework Solutions

In recent times, and with good reason - as attacks by worms such as Code Red, Nimbda, and Slammer have shown - security has been pushed to the forefront of the minds of architects and developers. And just as Microsoft has rededicated itself to security through its Trustworthy Computing Initiative, your organization should be sure to design and implement its applications using secure coding practices and principles. Even though .NET Compact Framework applications may at first appear immune to such attacks, their connection to back-end systems and their portability introduce a variety of security risks that must be mitigated.

In this column we'll review what you'll need to consider to implement security at the device, application, and communication layers.

Secure the Device
The first layer of security to consider is that provided by the device itself. In addition to relying on mechanisms provided by the device manufacturer or platform (such as the Pocket PC running on Windows CE), your organization can augment the OS software with third-party solutions. Generally, the types of security that can be used to protect the device fall into the categories of authentication, antivirus protection, and lockdown.

  • Authentication: The simplest step organizations can take to protect devices on which Compact Framework applications run is to require some form of authentication. For example, Pocket PC 2002 and later devices running Windows CE support both simple and strong power-on password authentication. By enabling this feature on the device, the user must type in a simple four-character, or more complex seven-character, password at a configurable interval that defaults to one hour. If a user enters an incorrect password, an exponentially increasing time delay is enforced, making it very difficult to repeatedly guess the password. Third-party vendors, such as Trust Digital LLC through its PDASecure product, provide power-on password authentication with additional options that include locking the device after a certain number of invalid password attempts and additionally requiring a soft reset, hard reset, or even "wiping" the device of its data.

    Although this form of authentication can be quite effective, it is based on knowledge of a password that can perhaps be obtained through illegitimate means. To implement authentication based on possession of a physical item like a smart card or a cryptographic certificate located on a removable storage card, or based on user identity through biometric (e.g., fingerprint) or signature identification, third-party products are required. Vendors such as A2000 Distribution, Certicom Corporation, and Cloakware Corporation provide a variety of such solutions.

  • Antivirus Protection: Even though viruses that target mobile devices are not as prevalent as those targeting desktop computers, they are still a potential threat to any software on the device. Typically, however, devices are not damaged by viruses but rather pass them into a corporate network via e-mail attachments and documents. There are, as you might expect, a variety of antivirus packages on the market for devices such as the Pocket PC, from vendors including McAfee, Computer Associates, and F-Secure. Additionally, personal firewall products such as VPN-1 are available from vendors such as Check Point Software Technologies Ltd.

  • Lockdown: Following the accepted security principle of "reducing the attack surface," many organizations may wish to disable some features of the device. Third-party software such as PDASecure, for example, does just that by password protecting or disabling infrared communications, ActiveSync, and the voice recorder.

    Secure the Application
    The second layer to which security should be applied is the application itself. Typically, such security includes the concepts of authentication, data protection, and user input.

  • Authentication: Of course, the main way to secure an application on the device is by requiring the user to present credentials in order to be authenticated by the application. However, depending on what data source the application uses and how it creates a connection, this process can vary greatly. For example, a Compact Framework application might need to authenticate directly to SQL Server when using the SQLClient .NET Data Provider, to a Web server and SQL Server when using Remote Data Access or replication with SQL Server 2000 Windows CE Edition (SSCE), through a SOAP request when using an XML Web service, or through HTTP when using the HTTP pluggable protocol.

    In each of these cases your application must manage the credentials. In the case where multiple sets of credentials are required (for example, for a proxy and Web server in addition to SQL Server) it is a good practice to store the credentials in an encrypted database or file on the device or even on a storage card that is required to be inserted before the application can run.

  • Data protection: This concept involves two key aspects. First, any local data used by the application must be secured. This can be most easily accomplished using the built-in encryption feature of SSCE, which encrypts the database using the RC4 symmetric encryption algorithm with a key generated from an MD5 hash of the password (which implies that the strength of the encryption is dependent on the length of the password chosen). However, if local data is stored in a file it will need to be encrypted using the CryptoAPI (which supports 128-bit encryption on Pocket PC 2002 and Pocket PC 2000 with the Microsoft High Encryption Pack installed) since the System.Security. Cryptography namespace is not supported in the Compact Framework. Additionally, third-party encryption tools such as PDASecure support encryption of individual files.

  • User input: As codified in the "Don't Trust User Input" security principle, you need to secure user input. This issue is most directly relevant when accepting user input that is subsequently used to query or update data in SSCE or on a remote SQL Server. Malicious users may attempt to insert or inject additional SQL into a TextBox control, thereby causing a possibly harmful statement to run against the database. Such SQL injection attacks can be mitigated by cleansing user input with a function. In general, user input can be checked using regular expressions through the RegEx class of the System.Text.RegularExpressions namespace. One interesting use of this class is to create a derived TextBox control that uses a regular expression to validate the text entered by the user.

    Secure the Channel
    The final aspect to securing an application involves securing the transmission of data across the network. This aspect can involve a wide range of issues, including the use of Secure Sockets Layer (SSL), Virtual Private Networks (VPNs), and Wired Equivalent Privacy (WEP).

  • Secure Sockets Layer: The most fundamental way to secure the communication channel between a device and network is the use of SSL over HTTP. Simply put, SSL uses public- and private-key encryption based on the RSA algorithm, along with the use of a digital certificate to encrypt all of the communication between a client and a server. Fortunately, support for 128-bit SSL is built into both Pocket PC 2002 and 2000 devices (with the Microsoft High Encryption Pack installed). Since SSL is used over HTTP, Compact Framework applications can use it when connecting to a back-end server using SSCE connectivity, XML Web services, or the HTTP pluggable protocol.

    On the server side, the IIS server must have a digital certificate installed for the virtual directory in which the resource (the HTML page, for example) resides. The certificate may be either one obtained from a trusted certificate authority such as VeriSign or one generated internally within the organization using Microsoft Certificate Server. In the latter case the root certificate for your organization must also be installed on the device.

  • Virtual private networks: A second option for encrypting the communication channel is the use of VPNs that rely on protocols such as the Point-to-Point Tunneling Protocol (PPTP) and the IP security protocol (IPSec) to both authenticate and encrypt communications. While Pocket PC 2002 and Windows CE .NET 4.1 devices do not support IPSec, they do support PPTP when setting up connections in the Connections tab of the device Settings. After entering the address of the VPN server for the connection, the device will prompt the user for credentials when a connection is made. In order to provide VPN functionality to Pocket PC 2000 devices or to use IPSec, a number of third-party products are available from vendors, including Certicom Corporation and Check Point Software Technologies.

  • Wired Equivalent Privacy: In wireless networks, unlike in wired LANs, walls are ineffective as a means of security since radio waves are not bound by the walls used to protect the network. A first-generation technology used to protect such networks was based on the WEP security protocol. However, this protocol was found to contain flaws that left it vulnerable to attack. As a result, WEP is considered unsecure and should not be used without additional security such as VPNs or SSL.

    Although an initiative called WEP2 was developed to address the issues with WEP, many in the industry felt it too was vulnerable to attack. However, the 802.11i standard, currently in draft form, addresses many of these security issues. While the new specification is being ratified, wireless vendors have agreed on an interim solution called Wi-Fi Protected Access (WPA). WPA support is currently being rolled out in products such as Funk Software's Odyssey Client and Meetinghouse Data Communications' AEGIS Client. In the interim other organizations using server and client software primarily from Funk and Meetinghouse have gone forward and implemented the Extensible Authentication Protocol (EAP) over the competing Tunneled Transport Layer Security (TTLS) protocol developed by Funk and Certicom and the Protected Extensible Authentication Protocol (PEAP) developed by Microsoft and Cisco Systems to allow secure access to WLANs on their corporate campuses. In addition, third parties such as MobileSys, Inc., and Altarus Corporation offer wireless encryption technology.

    Security Is Key
    We hope this column has given you a framework for thinking about how to secure your .NET Compact Framework applications.

  • More Stories By Jon Box

    Jon Box is an Architect Evangelist in Developer & Platform Evangelism with the Microsoft Corporation. He coauthored Building Solutions with the Microsoft .NET Compact Framework, published by Addison-Wesley, and blogs at http://blogs.msdn.com/jonbox/default.aspx.

    Comments (0)

    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.


    @ThingsExpo Stories
    "Evatronix provides design services to companies that need to integrate the IoT technology in their products but they don't necessarily have the expertise, knowledge and design team to do so," explained Adam Morawiec, VP of Business Development at Evatronix, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
    Recently, REAN Cloud built a digital concierge for a North Carolina hospital that had observed that most patient call button questions were repetitive. In addition, the paper-based process used to measure patient health metrics was laborious, not in real-time and sometimes error-prone. In their session at 21st Cloud Expo, Sean Finnerty, Executive Director, Practice Lead, Health Care & Life Science at REAN Cloud, and Dr. S.P.T. Krishnan, Principal Architect at REAN Cloud, discussed how they built...
    No hype cycles or predictions of a gazillion things here. IoT is here. You get it. You know your business and have great ideas for a business transformation strategy. What comes next? Time to make it happen. In his session at @ThingsExpo, Jay Mason, an Associate Partner of Analytics, IoT & Cybersecurity at M&S Consulting, presented a step-by-step plan to develop your technology implementation strategy. He also discussed the evaluation of communication standards and IoT messaging protocols, data...
    With tough new regulations coming to Europe on data privacy in May 2018, Calligo will explain why in reality the effect is global and transforms how you consider critical data. EU GDPR fundamentally rewrites the rules for cloud, Big Data and IoT. In his session at 21st Cloud Expo, Adam Ryan, Vice President and General Manager EMEA at Calligo, examined the regulations and provided insight on how it affects technology, challenges the established rules and will usher in new levels of diligence arou...
    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. In his session at @BigDataExpo, Jack Norris, Senior Vice President, Data and Applications at MapR Technologies, reviewed best practices t...
    Smart cities have the potential to change our lives at so many levels for citizens: less pollution, reduced parking obstacles, better health, education and more energy savings. Real-time data streaming and the Internet of Things (IoT) possess the power to turn this vision into a reality. However, most organizations today are building their data infrastructure to focus solely on addressing immediate business needs vs. a platform capable of quickly adapting emerging technologies to address future ...
    In his Opening Keynote at 21st Cloud Expo, John Considine, General Manager of IBM Cloud Infrastructure, led attendees through the exciting evolution of the cloud. He looked at this major disruption from the perspective of technology, business models, and what this means for enterprises of all sizes. John Considine is General Manager of Cloud Infrastructure Services at IBM. In that role he is responsible for leading IBM’s public cloud infrastructure including strategy, development, and offering m...
    In his session at 21st Cloud Expo, Raju Shreewastava, founder of Big Data Trunk, provided a fun and simple way to introduce Machine Leaning to anyone and everyone. He solved a machine learning problem and demonstrated an easy way to be able to do machine learning without even coding. Raju Shreewastava is the founder of Big Data Trunk (www.BigDataTrunk.com), a Big Data Training and consulting firm with offices in the United States. He previously led the data warehouse/business intelligence and B...
    The 22nd International Cloud Expo | 1st DXWorld Expo has announced that its Call for Papers is open. Cloud Expo | DXWorld Expo, to be held June 5-7, 2018, at the Javits Center in New York, NY, brings together Cloud Computing, Digital Transformation, Big Data, Internet of Things, DevOps, Machine Learning and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding busin...
    Nordstrom is transforming the way that they do business and the cloud is the key to enabling speed and hyper personalized customer experiences. In his session at 21st Cloud Expo, Ken Schow, VP of Engineering at Nordstrom, discussed some of the key learnings and common pitfalls of large enterprises moving to the cloud. This includes strategies around choosing a cloud provider(s), architecture, and lessons learned. In addition, he covered some of the best practices for structured team migration an...
    22nd International Cloud Expo, taking place June 5-7, 2018, at the Javits Center in New York City, NY, and co-located with the 1st DXWorld Expo 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 ...
    22nd International Cloud Expo, taking place June 5-7, 2018, at the Javits Center in New York City, NY, and co-located with the 1st DXWorld Expo 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 ...
    DevOps at Cloud Expo – being held June 5-7, 2018, at the Javits Center in New York, NY – announces that its Call for Papers is open. Born out of proven success in agile development, cloud computing, and process automation, DevOps is a macro trend you cannot afford to miss. From showcase success stories from early adopters and web-scale businesses, DevOps is expanding to organizations of all sizes, including the world's largest enterprises – and delivering real results. Among the proven benefits,...
    @DevOpsSummit at Cloud Expo, taking place June 5-7, 2018, at the Javits Center in New York City, NY, is co-located with 22nd Cloud Expo | 1st DXWorld Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait...
    Cloud Expo | DXWorld Expo have announced the conference tracks for Cloud Expo 2018. Cloud Expo will be held June 5-7, 2018, at the Javits Center in New York City, and November 6-8, 2018, at the Santa Clara Convention Center, Santa Clara, CA. Digital Transformation (DX) is a major focus with the introduction of DX Expo within the program. Successful transformation requires a laser focus on being data-driven and on using all the tools available that enable transformation if they plan to survive ov...
    SYS-CON Events announced today that T-Mobile exhibited at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. As America's Un-carrier, T-Mobile US, Inc., is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to 67.4 million customers who are unwilling to compromise on qua...
    SYS-CON Events announced today that Cedexis 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. Cedexis is the leader in data-driven enterprise global traffic management. Whether optimizing traffic through datacenters, clouds, CDNs, or any combination, Cedexis solutions drive quality and cost-effectiveness. For more information, please visit https://www.cedexis.com.
    SYS-CON Events announced today that Google Cloud has been named “Keynote 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. Companies come to Google Cloud to transform their businesses. Google Cloud’s comprehensive portfolio – from infrastructure to apps to devices – helps enterprises innovate faster, scale smarter, stay secure, and do more with data than ever before.
    SYS-CON Events announced today that Vivint to exhibit at SYS-CON's 21st Cloud Expo, which will take place on October 31 through November 2nd 2017 at the Santa Clara Convention Center in Santa Clara, California. As a leading smart home technology provider, Vivint offers home security, energy management, home automation, local cloud storage, and high-speed Internet solutions to more than one million customers throughout the United States and Canada. The end result is a smart home solution that sav...
    SYS-CON Events announced today that Opsani 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. Opsani is the leading provider of deployment automation systems for running and scaling traditional enterprise applications on container infrastructure.