Exploiting Devices Lacking SSL Protection at Toorcon

A review of the event from CNET is available here:  https://www.cnet.com/news/researchers-hack-toys-attack-iphones-at-toorcon/.

Of particular interest is Firesheep: http://codebutler.com/firesheep, a firefox browser extension for simplifying SideJacking of open wireless networks.  It is open source, courtesy of Eric Butler and Ian Gallagher.  Their stated goal for developing the tool is creating more awareness of the problem.  We think they’ll achieve their goal!

As a vendor of embedded SSL, you can probably imagine what we think about this, but repetition is the mother of learning, so we’ll repeat:  If you’re building software for embedded devices, you need to enable SSL/TLS.  The most efficient tool for doing that on an embedded environment is wolfSSL.

Need help enabling ssl your device?  Contact us at info@yassl.com

OCSP, RFC 2560 for Embedded SSL

Hi!  Do you need OCSP (Online Certificate Status Protocol) in wolfSSL?  Let us know.  We’re currently considering it for a feature addition to our next release.  Sometimes OCSP may be necessary to obtain timely information about the revocation status of a certificate.  OCSP solves that problem.  Additional status information is also available under the protocol.  More information on the protocol is available here:  http://www.ietf.org/rfc/rfc2560.txt.  This is not a big feature for us to add, but we’re weighing it against other development priorities.  So let us know what you think!  Send in your vote  for or against OCSP being a high priority for wolfSSL to info@yassl.com.

yaSSL Embedded Web Server – CGI Support

The yaSSL Open Source Embedded Web Server has support for CGI (Common Gateway Interface). Using CGI, a web server can communicate with other types of programs running on the server. Because the yaSSL Embedded Web Server by itself is only able to deal with HTML file, it can “pass off” scripts written in other languages to their specific interpreter, thus allowing the functionality of many CGI languages to be used. Some of the possible languages include: PHP, Perl, ASP, ASP.NET, Python, Ruby on Rails, and C.

To configure the yaSSL Embedded Web Server to process CGI scripts in a given language, the interpreter for that language must be installed on the server. As an example, we’ll walk through how you would enable PHP to be used with the yaSSL Embedded Web Server.

The first thing you would need to do would be to download PHP if it is not currently installed on your server. The PHP source can be downloaded from the following location: http://www.php.net/downloads.php. After it has been downloaded, it should be built and installed. From the php source directory, run the following commands:

sudo make install

On OS X, this will place the “php-cgi” program in the “/usr/local/bin” directory. Now that we have the PHP CGI interpreter, we need to let the yaSSL Web Server know where it is located. This can be done in two ways (as most options can) and be set at runtime using the -cgi_interp option, or by adding a similar line to the configuration file. We can also set the -cgi_ext option, which defines which extensions are treated as CGI scripts. Setting these option at runtime, you would start the yaSSL Embedded Web Server as follows:

./yasslEWS -cgi_ext cgi,php -cgi_interp /usr/local/bin/php-cgi

After starting the web server, you can test if PHP is working by browsing to any PHP file which is located under your web server root directory.

To download the yaSSL Embedded Web Server, or to learn more, check out http://www.yassl.com. If you have any questions, contact us at info@yassl.com.

yaSSL Embedded Web Server – Alias Support

The yaSSL Open Source Embedded Web Server supports directory aliases. Similar to Apache’s mod_alias, using aliases allows a mapping to be created between URLs and file system paths. This mapping allows content which is not under the web server Document Root to be served as part of the web document tree. In other words, URLs beginning with the url-path will be mapped to local files beginning with the directory-path.

In the yaSSL Embedded Web Server, this can be done two ways:

1) Aliases can be set at runtime by using the -aliases option
2) Aliases can be set in the config file

In the following examples, suppose we wanted to map our local video directory (/home/user/Videos) to the URL “/videos”, and we wanted to map our pictures directory (/home/user/Pictures) to the URL “/pictures”.

Using the first option (setting the aliases at runtime), would look similar to the following.

./yasslEWS -aliases /videos=/home/user/Videos,/pictures=/home/user/Pictures

Using the second option (setting the aliases through the config file), we would need to add a line to our config file, as follows:

aliases /videos=/home/user/Videos,/pictures=/home/user/Pictures

To test if the newly set-up aliases are working correctly, point your web browser to one of the two URLs, where you should see a directory listing of the local files.


If this doesn’t work, double check that your paths are correct in your alias definitions and that everything is spelled correctly. Aliases should be able to be created for any drive physically attached to your computer.

To download the yaSSL Embedded Web Server, or to learn more, check out http://www.yassl.com. If you have any questions, contact us at info@yassl.com.

yaSSL Embedded Web Server – ACL Support

The yaSSL Open Source Embedded Web Server supports Access Control Lists. An Access Control List (ACL) allows restrictions to be put on the list of IP addresses which have access to the web server. In the case of the yaSSL Embedded Web Server, the ACL is a comma separated list of IP subnets, where each subnet is prepended by either a ‘-’ or a ‘+’ sign. A plus sign means allow, where a minus sign means deny. If a subnet mask is omitted, such as “-”, this means to deny only that single IP address.

Subnet masks may vary from 0 to 32, inclusive. The default setting is to allow all, and on each request the full list is traversed – where the last match wins.

The ACL can be specified either at runtime, using the -acl option, or by using “acl” in the config file. For example, to allow only the subnet to connect, you would run the following command:

./yasslEWS -acl -,+

The ACL can also be set in the web server config file. Using the example above, the config file line would be:

# acl -,+

To learn more about subnet masks, see the Wikipedia page on Subnetwork (http://en.wikipedia.org/wiki/Subnetwork), or here (http://wiki.xtronics.com/index.php/IP_Subnet_Masks).

To download the yaSSL Embedded Web Server, or to learn more, check out http://www.yassl.com. If you have any questions, contact us at info@yassl.com.

yaSSL Embedded Web Server – SSI Support

One of the features of the yaSSL Embedded Web Server is support for Server Side Includes. Server Side Includes (SSI) is a simple interpreted server-side scripting language which is most commonly used to include the contents of a file into a web page. It can be useful when it is desirable to include a common piece of code throughout a website.

Some of the ways in which Sever Side Includes may be used include:
– Including the contents of a file (html, txt, etc) into a web page
– Include the result of running a CGI script
– Executing a program, script, or shell command on the server
– Displaying the contents of a HTTP environment variable
– Outputting a list of variables and their values (environment and user-defined)

For more information on Server Side Includes, take a look at the Wikipedia entry here: http://en.wikipedia.org/wiki/Server_Side_Includes, or a tutorial on Server Side Includes can be found here: http://http-server.carleton.ca/~dmcfet/html/ssi.html.

To download the yaSSL Embedded Web Server, or to learn more, check out http://www.yassl.com. If you have any questions, contact us at info@yassl.com.

Open Source Embedded Web Server

Have you checked out the yaSSL Embedded Web Server?  With SSL enabled, it is sized small enough to fit into resource constrained environments at under 200k in footprint.  However, it still has a useful feature set, including all of the standard web server functionality you would expect, plus features like support for CGI with your favorite language, including PHP, Perl, Python, Ruby on Rails, etc.  Check it out at www.yassl.com.

Embedded SSL in the Holiday Spirit

Team yaSSL is preparing for Halloween here in the United States with a pumpkin carving! Our embedded security products are continually evolving. We encourage you to check our our wolfSSL embedded SSL library here, or our new yaSSL Embedded Web Server, here.

As always if you have any questions, or would like more information about our products, please contact us at info@yassl.com.

Team yaSSL

Great Article on Smart Meters in EE Times

See https://www.embedded.com/design/power-optimization/4209515/Robust-design-principles-for-home-smart-grid-metering for a great discussion on smart grid metering.  There’s already wolfSSL users employing our embedded ssl to secure metering systems!  wolfSSL is useful in smart grid metering for the following areas:
1. Delivering secure firmware updates to the metering device.
2. Encrypting data between the metering device and the main data store.
3. Encrypting data on the device.
Are you building smart grid devices?  Let us know if we can help you with security concerns by contacting us at info@yassl.com.

Notes from wolfSSL at Embedded Systems Computing show in Boston

Hi!  A few notes from exhibiting at Embedded Systems Computing show in Boston.  

1. It`s always fun to hear about what people are doing with embedded systems.  We heard lots of interesting stories about the devices people are building… and securing.

2. The diversity of embedded systems is still amazing, and growing.  From pico-sensors to POS to UAV`s.

3. Team wolfSSL was lucky enough to make it out to Fenway to watch the Red Sox!  Nice to see that historic stadium and see some professional baseball players.  Check out our pictures on Facebook.

4. Feedback on the new yaSSL Embedded Web Server was fun!  Lots of people with lots of interesting ideas on where and why to put a web server on a device!

5. Kerberos Consortium:  We made time to visit the leadership of the Kerberos Consortium at MIT http://www.kerberos.org/.  More on that in a following blog post!

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