Support for AES-NI in Visual Studio

Hi!  We`ve been supporting AES-NI for a few years now.  We`ve decided to extend that support to Visual Studio users.  If you would like to use AES-NI with Visual Studio, then let us know.  Beta code will be available shortly.  Contact us at if you have questions.

wolfSSL Releases IoT Demo of CyaSSL Working with Xively and mbed

For those of you interested in how CyaSSL fits into IoT, here is an example you should take a look at!

We have prepared a demo with CyaSSL, Xively, and mbed. It runs on various mbed platforms with Ethernet connections, including NXP LPC1768 whose RAM size is as small as 32k for applications + 32k for drivers.

In the demo configuration, mbed sends sensor data every 10 seconds through SSL to the Xively server, and you can see it through the browser on your pc.

 “mbed with Sensors” –[https]–> “Xively Server” <–[https]– “Browser on PC”

Xively is a cloud IoT service. It provides both HTTP and HTTPS APIs for IoT clients, in which they highly recommend HTTPS for obvious reasons, especially for commercial applications.

The demo includes the CyaSSL-based https client class. It is forked from the standard mbed http client class. So you can find out how it can be embedded into a socket-based program as well.

To use the project, please go to our mbed site and import the demo.

For more information:



mbed HTTPClient class:

wolfSSL Enforces Stack Usage Reduction

Understanding the stack and the heap are fundamental steps for all software developers. The importance of such understanding is inversely proportional to the amount of memory available on the platform, as both compete for a piece of the total memory space available on a system.

In some cases the developer has the choice of when to use one (either the stack or heap) more than the other. In other cases, a scenario may force the developer to work with minimal use of the stack, the heap, or both.

With this in mind, wolfSSL is introducing a new build option in CyaSSL. Developers can now choose a CyaSSL build that best matches their needs of using more stack and less heap OR more heap and less stack. This process is being accomplished by the refactoring of the CyaSSL code. Currently 90% of the encryption layer has been refactored to use the new option.

Small stack usage is not enabled by default. To enable it users must use the option “–enable-small-stack” when configuring the CyaSSL build as in the following example:

./configure –enable-small-stack [other options]

For users who don`t use CyaSSL`s configure script for compilation, smaller stack usage is not enabled by default. In this case, users will need to add the compiler directive CYASSL_SMALL_STACK in config.h file or settings.h to enjoy its benefits as in the following example:




If you have any questions about stack usage with CyaSSL please let us know at

wolfSSL with TLS 1.3

Hi!  Some of you know that the IETF working group on TLS is creating the specification for TLS 1.3.  We plan to upgrade wolfSSL to the TLS 1.3 specification as soon as the spec is finalized, or even close to finalized.  We are always aggressive with implementing the new TLS specifications, because we like to supply the community with a good test bed.  We did a great job getting TLS 1.2 out right away, as well as DTLS 1.2, and the community appreciated the effort.  We plan to continue our tradition of being quick with new protocol level changes.  

If you`re interested in what TLS 1.3 thinking is so far, then look here:  If you have TLS 1.3 questions or comments, you are welcome to email us at or call us at +1 425 245 8247.

wolfSSL 3.0.0 Released

The new release of wolfSSL, v3.0.0, is now ready to download from our website.  New features include:

– FIPS release candidate
– X.509 improvements that address items reported by Suman Jana with security researchers at UT Austin and UC Davis
– Small stack size improvements, –enable-smallstack. Offloads large local variables to the heap. (Note this is not complete.)
– Updated AES-CCM-8 cipher suites to use approved suite numbers.

Please see the README and our on-line documentation for more information or feel free to contact us.