Using wolfSSL with .NET Core

.NET Core is a .NET implementation that is preferred in situations where cross platform portability is important. Including use in containers and running on environments such as macOS and Linux. wolfSSL has a C# wrapper written for the .NET framework that is fully capable of performing TLS/DTLS connections while using the optimized C code with hardware acceleration. Easy to use examples for a quick start are also bundled with the wolfSSL C# wrapper which can be seen in the directory wolfssl-4.5.0/wrapper/CSharp/ after downloading wolfSSL.

Using Microsoft’s “.NET portability tester” tool to evaluate wolfSSL’s C# implementation resulted in a rating of 95.6% compatible for transitioning over to .NET Core. Showing that the implementation is close, as is, to being able to be used with .NET Core. If using the progressive wolfSSL C# wrapper with .NET Core is something you are interested in, contact us at for more information.

What’s New in FIPS 140-3?

There are a few significant changes coming with FIPS 140-3. Over the years with many specification updates, a few things got a little inconsistent, so these inconsistencies have been brought back in line. wolfSSL is prepared to deliver the first and best implementation of FIPS 140-3, so get ready:

  • The power-on self-test is changing. It now takes two sets of tests: the Pre-operational Self-Test (POST) and the Conditional Algorithm Self-Test (CAST).
  • The old Known Answer Tests used as a part of the old test are not required to run at startup. They are now conditional tests that must be run right before use of an algorithm. If you don’t use an algorithm, you don’t need to test it. The tests will run automatically on calling any API for an algorithm.
  • The pre-operational self-test is now purely an integrity test of the executable in memory. The algorithms used for this test must be tested first. In our case, HMAC-SHA-256’s CAST is run automatically, then the POST. The POST will be run automatically as wolfCrypt’s default entry point in the code.
  • All the tests may be and should be run periodically during run time. We will provide an API to run tests as desired. In an embedded application, you can run your CAST early before any algorithms are used as some CASTs do take time.

wolfSSL has a long history in FIPS 140-2, starting with wolfCrypt FIPS 140-2 Level 1 Certificate #2425 and surviving Certificate #3389. wolfSSL is helping customers move from Certificate #2425 as NIST is sending it into sunset next year. For those who will be impacted, contact us to get your new cert!

wolfSSL is currently the leader in embedded FIPS certificates. Stay tuned as we support you with the best in FIPS 140-3. Be sure to join us for an upcoming webinar on this topic, details forthcoming! 


Additional Resources 

For more information on FIPS or to write to us about your FIPS requirements, please send a note to

Check out the wolfSSL embedded SSL/TLS library, star us on Github, and learn more about the latest TLS 1.3 is available in wolfSSL. 

wolfSSL-NXP Partnership Roundup

NXP® Semiconductors N.V. is one of the wolfSSL partner network members. wolfSSL ships with support for offloading cryptographic operations onto several NXP devices (such as the Coldfire and Kinetis) that include hardware cryptography modules. Examples of these operations include utilizing the Crypto Acceleration Unit (CAU), Memory-Mapped Crypto Acceleration Unit (mmCAU), LP Trusted Crypto (LTC), and more.

Using these hardware cryptography modules leads to increased performance when compared to performing hardware cryptography within software only. These speedups increase algorithm performance greatly, and can range from 1.2 times as fast to 14.5 times as fast! In an embedded and connected world, these speedups can make all the difference for an online device or network application. Additionally, these performance increases are available when wolfSSL is being used to manage TLS 1.3 connections, giving your embedded SSL/TLS application the ability to greatly increase performance and use the most up-to-date versions of the TLS protocol.

Benchmark numbers showing the comparison of hardware crypto vs. software crypto can be viewed on the wolfSSL benchmark page, here: This page also includes sample benchmark data for the NXP i.MX6, and the TWR-K70F120M devices. More benchmarks, and details about wolfSSL and NXP can be viewed on the wolfSSL website:


More News on wolfSSL Support for NXP

wolfSSL develops a full suite of products supporting NXP designs. Learn about wolfBoot secure boot and TLS 1.3 firmware update with FreeRTOS and wolfSSL on NXP Freedom Board K64 here. And as with every release cycle, 4.2.0 improved support for crypto hardware performance, now on NXP mmCAU (download the latest wolfSSL version 4.5.0 here!) 

wolfSSL also provisions surviving FIPS certificates that can be leveraged for your i.MX8, i.MX7 and i.MX8 CAAM projects. Stay tuned for upcoming FIPS 140-3 support. Also on the roadmap, upcoming support for NXP’s SE050 hardware security chip. This is an external I2C crypto co-processor chip that supports RSA key sizes up to 4096-bit, ECC curves up to 521 bit and ED25519/Curve25519. If your target is missing, tell us!

Write to us at so we can learn more about your NXP projects! 



NXP Semiconductors:

TLS 1.3:


Upcoming Partner Webinar with iWave

We are thrilled to announce a partner webinar with iWave!

wolfSSL and iWave have partnered together to enable embedded TLS in the iWave portfolio of embedded solutions. iWave is a global embedded solution provider that offers a wide array of rugged and high-performance System on Modules (SoMs) and Single Board Computers (SBCs) build on NXP i.MX6, i.MX8 series of Processors and INTEL FPGA series. This partnership allows iWave to strengthen their product offerings by utilizing the wolfSSL embedded SSL/TLS library and hardware crypto support, including CAAM, onto the System on Modules and embedded solutions.

Join us for this special session on:

Oct 8, 2020 07:00 AM Pacific Time (US and Canada)

Watch the webinar here: iWave Security IP Suite Enabled with WolfSSL

About Our Partner

iWave Systems Technologies Pvt. Ltd., established in the year 1999, focuses on product engineering services involving embedded hardware design and development, software development and FPGA services. iWave is a global leader in design and manufacturing of System on Modules based on NXP, Xilinx and INTEL chipsets.

Read More

Blackhat Asia 2020

wolfSSL will be attending Black Hat Asia! This event will be held virtually in the Singapore Time Zone from September 29-October 2. During this week, information security experts will teach interactive, online Trainings, innovative research will be presented at Briefings, the latest open-source tools will be showcased at Arsenal, and the Business Hall will feature top-tier security solutions and service providers, plus ample networking events and opportunities.

Who We Are

wolfSSL focuses on providing lightweight and embedded security solutions with an emphasis on speed, size, portability, features, and standards compliance, such as FIPS 140-2 and 140-3, RTCA DO-178C level A certification, and support for MISRA-C capabilities. wolfSSL supports industry standards up to the current TLS 1.3 and DTLS 1.2, is up to 20 times smaller than OpenSSL, offers a simple API, an OpenSSL compatibility layer, is backed by the robust wolfCrypt cryptography library, and much more. Our products are open source, giving customers the freedom to look under the hood.

See you there!

Contact Us 

Please contact us at with any questions about the webinar. For technical support, please contact or view our FAQ page. As always, there will be a Q&A session following the live presentation. 

Additional Resources 

In the meanwhile, check out the wolfSSL embedded SSL/TLS library, star us on Github, and learn more about the latest TLS 1.3 is available in wolfSSL. 

Upcoming Webinar: wolfSSL for STM32CubeMXv6

We are excited to announce our upcoming webinar: wolfSSL for STM32CubeMXv6! Join us for a 1-hour webinar to learn how wolfSSL & ST can easily integrate in STM32CubeMX projects.

You will learn:

  • New features of the latest STM32CubeMX tool from ST
  • How wolfSSL embedded security features set users ahead of the pack with speed, portability and feature set
  • How to easily integrate wolfSSL into your project using the STM32CubeMX tool

There will be a live Q&A session at the end of the webinar where ST and wolfSSL’s experienced engineers will be available to answer your questions.

By registering for this webinar, you submit your information to STMicroelectronics and wolfSSL and their distributors, who will use it to communicate with you regarding this event and their other services.

Latest updates on STMicroelectronics and wolfSSL: 

wolfSSL, an ST Authorized Partner, now offers support for STM32Cube pack for STM32, adding on to previous support for the STM32 Standard Peripheral Library as well as the STM32Cube HAL (Hardware Abstraction Layer). wolfSSL also maintains and makes available an STM32Cube Expansion Package for wolfSSL to make it easy for users to pull wolfSSL directly into STM32CubeMX and STM32CubeIDE projects.

The wolfSSL embedded SSL/TLS library has support for several of the STM32 microcontrollers and for the hardware-based cryptography and random number generator offered by them as well. Our most recent update is that wolfSSL now offers support for Cube pack for STM32, adding on to previous support for the STM32 Standard Peripheral Library as well as the Cube HAL (Hardware Abstraction Layer). wolfSSL also maintains and makes available an STM32Cube Expansion Package for wolfSSL to make it easy for users to pull wolfSSL directly into STM32CubeMX and STM32CubeIDE projects. 

A full list of STM32 benchmarks can be found here:

About STMicroelectronics 

STMicroelectronics is a global leader in the semiconductor market serving customers across the spectrum of sense and power and automotive products and embedded processing solutions. From energy management and savings to trust and data security, from healthcare and wellness to smart consumer devices, in the home, car and office, at work and at play, ST is found everywhere microelectronics make a positive and innovative contribution to people’s life. By getting more from technology to get more from life, ST stands for life.augmented.


Read our latest blog post about how the Cube pack for STM32 is now available! – wolfSSL

Check out the wolfSSL embedded SSL/TLS library, star us on Github, and learn more about the latest TLS 1.3 is available in wolfSSL.

Raccoon Attacks

If our little meme didn’t already convince you otherwise, raccoon attacks are not a big deal when it comes to wolfSSL, read more on our internal review of raccoon attacks here:!

To learn more about us, checkout the wolfSSL embedded SSL/TLS library, star us on GitHub, and find out more about using TLS 1.3 on wolfSSL! Contact us at with any questions and for technical support, email!

wolfSSL + Tenasys INTime RTOS

Did you know that wolfSSL includes a port to the Tenasys INTime RTOS? You can read more in our original press release from Tenasys here: Secured INtime system traffic!  Tenasys is using wolfSSL to secure their networked real-time systems and wolfSSL is happy to be integrated into the INTime networking stack which allows us to provide world renowned security to INTime SDK consumers.

wolfSSL also provides a FIPS 140-2 (and soon to be FIPS 140-3!) validated version of wolfCrypt! We also provide a “FIPS Ready” version of wolfSSL which is not associated with a FIPS validation, but includes FIPS-specific code. For users who may need a FIPS validated cryptography library in the future, FIPS Ready can be a good choice to make the transition as easy as possible.

If you have any questions, contact wolfSSL at


User-Generated Performance Advisory for Cortex M – Newlib vs Newlib-Nano

A big thank you to who has shared results for their own project in hopes of further helping fellow users when building on an embedded Cortex M platform.

“I had a working project build with Segger Embedded Studio for a Nordic NRF52840 (64MHz Cortex M). We switched our build tooling to use cmake/ninja along with the newlib-nano libraries packaged with ARM GCC tools. One thing I noticed is that our TLS handshake in our application went from 3 seconds to about 16 seconds.

Using the built in wolf test functions, I was able to track down the issue.

While Segger Embedded Studio uses GCC, they have their own builds of the C standard libraries.The wolfcrypt ECC routines are very sensitive to how the C libraries are built.



I could eventually get “better” performance than the SES custom library but had to use NewLib and not NewLib-nano. This results in a larger binary but the performance is much better.   


wolf Test Time 

Segger Embedded Studio w/ custom std libs: 208 seconds

ARM GCC Embedded w/ Newlib-Nano:  608 seconds

ARM GCC Embedded w/ Newlib:  202 seconds

ARM GCC Embedded w/ Newlib &WOLFSSL_SP_ARM_CORTEX_M_ASM :  175 seconds


In addition to using Newlib, I found the macro WOLFSSL_SP_ARM_CORTEX_M_ASM helped quite a bit.  (Appears it has hand tuned ASM routines for SP math).

Apparently, newlib is built with speed optimizations and newlib-nano is built with size optimizations. I was surprised at the stark difference. I have other math heavy routines and the difference in execution speed is only 5% between -03 and -Os.  It seems that the ECC SP routines have some sensitivity to the C library.

Hope this is helpful to anyone building for a Cortex M MCU.” 


To read the original forum post:

Thank you for sharing these findings. We hope others on the Cortex M will see this. The SP WOLFSSL_SP_ARM_CORTEX_M_ASM option is quite impressive for RSA/DH/ECC math speedups because it uses hand written assembly. At wolfSSL, we love to hear your findings and projects, so please feel free to reach out and keep us posted! 


Additional Resources 

Check out Eli’s article series for NXP on LPC55S69 and stay tuned for an upcoming set on cellular IoT and cloud connectivity. 

Please contact us at for any general questions and for technical support, please contact or view our FAQ page

Check out the wolfSSL embedded SSL/TLS library, star us on Github, and learn more about the latest TLS 1.3 is available in wolfSSL. 



This post has been cross posted from Daniel Stenberg’s blog – originally posted here.

We have started the work on extending wolfSSL to provide the necessary API calls to power QUIC and HTTP/3 implementations!

Small, fast and FIPS

The TLS library known as wolfSSL is already very often a top choice when users are looking for a small and yet very fast TLS stack that supports all the latest protocol features; including TLS 1.3 support – open source with commercial support available.

As manufacturers of IoT devices and other systems with memory, CPU and footprint constraints are looking forward to following the Internet development and switching over to upcoming QUIC and HTTP/3 protocols, wolfSSL is here to help users take that step.

A QUIC reminder

In case you have forgot, here’s a schematic view of HTTPS stacks, old vs new. On the right side you can see HTTP/3, QUIC and the little TLS 1.3 box there within QUIC.


There are no plans to write a full QUIC stack. There are already plenty of those. We’re talking about adjustments and extensions of the existing TLS library API set to make sure wolfSSL can be used as the TLS component in a QUIC stack.

One of the leading QUIC stacks and so far the only one I know of that does this, ngtcp2 is written to be TLS library agnostic and allows different TLS libraries to be plugged in as different backends. I believe it makes perfect sense to make such a plugin for wolfSSL to be a sensible step as soon as there’s code to try out.

A neat effect of that, would be that once wolfSSL works as a backend to ngtcp2, it should be possible to do full-fledged HTTP/3 transfers using curl powered by ngtcp2+wolfSSL. Contact us with other ideas for QUIC stacks you would like us to test wolfSSL with!

FIPS 140-2

We expect wolfSSL to be the first FIPS-based implementation to add support for QUIC. I hear this is valuable to a number of users.


This work begins now and this is just a blog post of our intentions. We and I will of course love to get your feedback on this and whatever else that is related. We’re also interested to get in touch with people and companies who want to be early testers of our implementation. You know where to find us!

I can promise you that the more interest we can sense to exist for this effort, the sooner we will see the first code to test out.

It seems likely that we’re not going to support any older TLS drafts for QUIC than draft-29.

wolfSSL offers commercial support packages and consulting for cURL and tiny-curl!  Contact us at to learn more.

wolfSSL supports Infineon AURIX Boards

Three years ago, wolfSSL partnered with Infineon, making it easier to ensure security on Infineon-based projects. Today wolfSSL continues to foster our relationship with Infineon, including support for the latest AURIX boards.  

AURIX (Automotive Real Time Integrated Next Generation Architecture) is a 32- bit Infineon microcontroller family targeting the automotive industry in terms of performance and safety. AURIX’s multicore architecture is based on up to three independent 32-bit TriCore CPUs.



Infineon designs, develops, manufactures and markets a broad range of semiconductors and system solutions. The focus of its activities is on automotive electronics, industrial electronics, mobile devices and chip card-based security. Combining entrepreneurial success with responsible action, Infineon addresses some of the most critical challenges of society: Efficient use of energy, environmentally friendly mobility and security in a connected world.

The wolfSSL embedded SSL/TLS library is a perfect fit for securing lightweight, resource-constrained devices. wolfSSL has a footprint size of 20-100kB, offers protocol support up to TLS 1.3 and DTLS 1.2, progressive algorithm support, hardware crypto support, and more.

Read more about our partnership with Infineon:


For more information regarding wolfSSL or any additional questions, please contact

In the meanwhile, check out the wolfSSLembedded SSL/TLS library, star us on GitHub, and learn more about the latestTLS 1.3 is available in wolfSSL.


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