Home > Articles > Operating Systems, Server > Linux/UNIX/Open Source

Security on a Dime: Low-Cost Alternatives to SSH

Need good security but short on spare change? IT guru and Open Source expert John Tränkenschuh discusses not-so-expensive technical architectures that offer the most basic SSH features across all platforms — not just Windows.
Like this article? We recommend

Like this article? We recommend

Production codes: - Title Page

I think all of us in the IT world are acclimated to the need to work with multiple platforms. Without a doubt, SSH’s ability to accommodate so many platforms, with commercial and Open Source alternatives, is great. That said, there is one platform best handled by the commercial versions: Windows. This is one very important platform, one whose servers tend to be in high numbers. This means a commercial solution can be an expensive option to achieve the goal of cross-platform interoperability.

This article discusses other technical architectures that can reproduce the most basic SSH features across all platforms.

Before that, let me openly discuss why the thought of implementing many Open Source SSH alternatives onto Windows sends me to commercial versions. To be sure, the commercial alternatives have a good security history. I really enjoy the great way SSH Communications has the essential SSH abilities in an easy-to-use software package. The issue is one of cost for many companies. So let’s begin by talking about SSH on Windows.

OpenSSH for Windows: Is Cygwin Good Enough?

The OpenSSH group does not code for Windows. Its website lists several excellent Windows clients, but we’re hunting servers... This has you stumbling about the Internet looking for a version others have created.

Stop.

This is a security tool, a part of your organization’s security architecture. One-guy, one-off tools are unacceptable if your information is truly confidential and needs security. Don’t try one of these projects unless there are several people and, hopefully, an organization providing support. My last Internet sampling showed too many dated projects, most of which used old versions of OpenSSH and Cygwin.

Stop.

Dated software can be unsafe software. Don’t install a free software package without looking into the details, such as version risks and intended use. What does Cygwin state about the intended use of its products?

In the past, Cygwin project leaders wrote about shared memory use possibly becoming security issues. Consider this posting at http://www.cygwin.com/ml/cygwin/2005-12/msg00077.html. I really respect Cygwin’s, um, Open discussion of possible issues. This is typical of the group’s honesty and integrity.

What are the challenges faced when attempting to map UNIX security attributes with Windows? Here again, the Cygwin group provides great information in http://www.cygwin.com/cygwin-ug-net/ntsec.html.

The Cygwin group’s stance regarding security is also repeated by the Apache HTTP Server Project group. Many people want to run Apache on Cygwin, itself running on Windows, to provide a UNIX layer that is familiar to UNIX administrators. In response, the Apache HTTP Server Project group states:

"...The Cygwin port may suffer from gaps in security or reliability due to the interaction of the Cygwin compatibility layer with the native Windows API."

The risks are stated plainly when comparing the Cygwin port with the Apache group’s own Win32 port:

"The Win32 port should be considered the more secure of the two at this time."

So let’s have no criticism of any Open Source project if you are hacked when using Cygwin and companion daemons in a security-sensitive context.

Consider the big differences in the security models for Windows and UNIX. Consider file permissions between the two operating systems. Mapping Windows’ many permission privileges into the UNIX 3×3 Factorial of user-group-"other" and read, write, execute/traverse directory is not easily done. Those who insist on using products that do this mapping with highly confidential information have only themselves to blame when hacked. I’m writing this in defense of any Cygwin, Apache, Samba, and other issues you may bring on yourself. Additionally, while no one has confirmed that the use of the shared memory in Cygwin may be a security risk, I look forward to an organization that takes up Corinna Vinschen’s offer of a support contract with Red Hat, to do a full security analysis.

So right now, you’re left needing a method to invoke shared processing across many platforms, potentially moving or gathering files. You need a technology that has deep support from the actual vendor and deep integration with the native security model for the platform, to avoid permission bit logical holes. You also want good memory management—one that doesn’t provide a common "info-kettle" from which others might fetch valuable data. Is there anything that can do this?

There sure is! Let’s go to the web.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020