Nasty New Car Attacks, Automobile Hacks

Carmakers these days are clearly seduced by the power automotive electronics have to help sell their cars.  At wolfSSL, we`re seeing more and more connected auto devices getting designed (and secured by CyaSSL) in recent years.  All of the carmakers and their suppliers we deal with are quite cognizant of the security risks their connected devices pose, and the need for high quality small footprint SSL/TLS and encryption in their cars to battle man in the middle attacks.  That said, given the state of flux of the `connected car`, the inexperience of many automotive electronics engineers with security considerations, hacks will happen.  Today we note a great article on the topic.  

Charlie Miller and Chris Valasek will be presenting a fresh round of Automobile Hacks at Defcon next month, and a well written teaser article on their work is available here from Andy Greenberg of Forbes:
(this article is no longer accessible on the forbes website as of Aug. 7, 2018)

If you`re at Black Hat or Defcon in the coming weeks, and want to discuss mitigating MITM automotive attacks with SSL, we`ll be available.  We`ve been helping automakers secure their electronics for 8 years now, and can share some of our experiences.  Just flag us down through

SSL and Cryptography in Software Defined Networks

Hi!  If you follow the networking market, you probably know that Software Defined Networks (SDN) represent a potential tectonic shift in how we think about and design network environments.  The concept has been around since 2005, but has gained significant momentum in the last couple of years, to the point where it is not just the talk of networking industry insiders, but has reached the mainstream financial press.  For a backgrounder on SDN, see

Our interest in SDN at wolfSSL is specific to the security aspects, and even more specifically to the SSL/TLS.  From our vantage point, there are a lot of things to think about, including SDN languages like Frenetic, standards like OpenFlow and vendors like IpInfusion and their ZebOS.  

Currently, we believe that hardware cryptography is critical to the successful rollout of SDN, primarily for performance reasons.  As such, we are actively integrating performant support for a variety of hardware crypto solutions.  Recent examples include support for Cavium, AES-NI, STMicroelectronics, and Freescale.  

It is still the early days for SDN, so we recognize that there are additional considerations for us beyond just hardware crypto.  We`d like your feedback.  If you have commentary on CyaSSL for SDN, then let us know at

Simon and Speck Lightweight Block Ciphers in wolfCrypt and wolfSSL

Last month the NSA released a paper on Simon and Speck, which are lightweight block ciphers that appear to be applicable to a large part of our embedded user base.  The paper can be found here:

Our users who have a keen interest in small size and low power consumption will find this paper particularly interesting.  

We are considering the possibility of implementing Simon and Speck in wolfSSL and WolfCrypt.  Does this sound interesting to you?  If your answer is yes, then let us know your thoughts at

wolfSSL 2013 First Half Report

wolfSSL has made considerable progress in the first half of 2013, including a company name change to wolfSSL,  improvements to the CyaSSL lightweight SSL library, initiation of our FIPS 140-2 certification, and the introduction of our wolfCrypt cryptography library.  Being an open source company, we like to keep our users, customers, and followers up to date on our progress.  As such, we have compiled an overview of wolfSSL`s steady development in the first half of 2013.

Business and Company Progress

– Successfully participated in the following events: CES 2013, RSA USA 2013, DESIGN West 2013, and Interop 2013.  
– Name change that better reflects our company and culture.  To us the wolf represents us well as it is a creature that communicates effectively, works well in groups, and shares with the pack.
– Added more developers to the team
– Increased activity in onsite consulting to help customers design and validate their security architectures
– Dramatic increase in design wins for wolfCrypt
– Added many more high profile customers
– On track to double our business again this year
– We continue to actively support the open source community

CyaSSL Technical Progress

– Timely fix for Lucky13 attack
– BLAKE2 (SHA-3 candidate) hash function support
– Memory/stack tracking with examples
– IPv6 example support including link local addresses
– Alignment support at the SSL layer for hardware devices that require it
– New configure switches per algorithm
– Wildcard domain name match check including Subject altnames
– Ability to unload certs/keys for lower memory use
– SNI (Server Name Indication) support
– DTLS 1.2 support including AEAD ciphers
– DTLS reliability enhancements
– SHA-384 cipher suites
– AES-CCM-8 crypto and cipher suites
– Camellia crypto and cipher suites
– Updated API documentation
– Added LeanPSK build option able to get size down to 20k

CyaSSL Porting Progress

– Cavium NITROX support
– Updated ThreadX/NetX support
– KEIL MDK-ARM project files
– Updated Xcode project file
– HP/UX support
– Microchip PIC32 support
– Microchip MPLAB X project files for PIC32 Ethernet Starter Kit
– STM32F2 support including hardware crypto and RNG


– Gearman now support CyaSSL

Team wolfSSL is looking forward to continued growth and development in the second half of 2013!  Stay tuned to our blog or social media streams to stay up-to-date on new developments.

Feedback Requested on Supported ECC Curves

The wolfSSL lightweight SSL library has supported ECC (Elliptic curve cryptography) since version 2.4.6 in December of 2012. Currently wolfSSL supports the most common ECC curve type at each bit strength defined by the standard, including the following.

  (also called PRIME192V1)
  (also called PRIME256V1)

wolfSSL defaults to SECP256R1, as is suggested, and as other SSL implementations do. We would like to get our users’ and readers’ feedback on these supported ECC curves. Are there additional curves you would like to see added to wolfSSL? If so, please let us know at

Some Notes on Testing wolfSSL

We are often asked about how we test wolfSSL.  At this point, we believe we have testing that is quite robust, but we acknowledge that there is no such thing as perfect testing.  With that knowledge in mind, we have the goal of incrementally improving and automating our testing rigs over time.  Our overriding goal in testing is to have the most advanced and robust and ever improving testing that we can, subject to our resources.

We used to think of our testing plans in terms of a hierarchy, but we`ve improved on that thinking over time.  We currently represent our testing as a series of concentric universes, with each successively larger universe being vastly larger and more complex than the smaller one inside of it.  We`ll post some pictures in upcoming blog posts.  For now, here`s a rough representation of our testing universes in order of sequence:  

1.  Build options:  We have an extremely large number of build option combinations.  So our most basic test universe is to build successfully with every possible combination of options.

2.  API testing:  We test every available call in a particular build.

3.  Connection testing and data passing variables:  We start with simple connection tests with limited data transmitted and then gradually dial up complexity.

4.  Interop:  We test for interoperability with the other open source TLS implementations, including OpenSSL and GnuTLS.

5.  We then connect to unknown servers in the real world.

6.  We then build with a series of `real` applications, like cURL, wget, pppd, etc.  For some of our customers with top level support, we build the new release with their application.

7.  Finally, we engage in another ever expanding universe of benchmark testing, where we look at sizing, transmission rates, connection speeds, etc.  More to come on that topic, as it is quite popular!

Much of our effort is automated by Jenkins (hat tip to that project!).  Thanks for listening.  If you have specific questions about how we test, please contact us at

Reduce Packet Data Overhead in M2M applications with wolfSSL

Many of our customers use the wolfSSL lightweight SSL/TLS package in M2M applications where usage is charged based on data transfer.  As such, it becomes important to minimize data transfer rates when running SSL.  Here are a few thoughts on how wolfSSL M2M users can minimize data packet overhead when implementing our embedded SSL:

1) Use a stream cipher like RC4, HC-128, or RABBIT.  Stream ciphers don`t require padding, this will save at least half the cipher`s block size per message.

2) Use session resumption as much as possible.  TLS session resumption uses less round trips and about 1/3 of the data compared to a full handshake, depending on certificate sizes and the certificate chain length mainly.  wolfSSL now has a built-in client session cache so using session resumption no longer places a burden on the application developer to map remote servers with session instances.

3) Only sending the peer certificate instead of certificate chains can greatly reduce the data usage of a full TLS handshake.  This will require the receiver to know about the root CAs and intermediate CAs ahead of time but it can often be worth it.

4) Use the shortest MAC you can, but still with good security.  This is probably SHA1 for now.  As more implementations begin to support truncated HMAC you could have the best of both.  SHA-384 for example, but truncated to 10 bytes.

5) Group output messages.  wolfSSL has the ability to send each TLS record individually or to send each group as flight.  This is a small savings, mainly in IP/TCP/TLS record headers but it adds up over time.

6) Use compression at the TLS level if you`re not doing it at the application level.  No sense in doing it twice though.