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First Secure CANcrypt CAN FD Bootloader available

July 19th, 2017 No comments

Today, the Embedded Systems Academy announces the availability of its secure CANcrypt CAN FD bootloader for the NXP LPC54618 microcontroller. The binary version is available as free download and may be used without limitations. For programming, the FlashMagic software ( and a PEAK PCAN-USB FD interface ( is required.

The security system is based on two symmetric keys, separating the code protection (happening at the manufacturer) from the download process done by a system integrator or service technician. The code file is AES-GCM (128-bit key) protected, offering both encryption and authentication. The local CAN FD connection (between service host and bootloader) is CANcrypt protected (128-bit key, authentication and partial encryption).

On the host side, the update process is fully integrated into the existing FlashMagic software that handles Flash programming for all NXP LPC microcontroller families.

Secure Bootloader Components

The figure illustrates the components of the system. The bootloader and the initial two keys (code protection, connection) are programmed into the LPC54618 device in a trustworthy manufacturer environment.

For a code update, the manufacturer creates a secure update file based on the first, code protection key. The file is encrypted and can be passed to the service technician through an unsecured channel such as email or web download. FlashMagic includes a minimal CANcrypt configurator, allowing the technician to initiate the code update using the second, CANcrypt connection key.

The secure bootloader does not by default disable the on-chip bootloaders and debug access by SWD to ensure that the default implementation can not accidentally lock a device. However, if all of these recovery methods are disabled, either during production or through a programmed application, then the secure bootloader remains the only method for code updates. In this configuration, once the CANcrypt connection key is lost, no further updates will ever be possible.

In addition to this free binary loader, ESAcademy offers a commercial version including all sources. This version offers more configuration options, such as customizing the CAN-FD bit rates (default is 500kbps/2000kbps) and security methods.

The security experts at MathEmbedded are in the process of reviewing the project. Once completed, we will publish the results here.

Download link:

MD5: 28a896e17a9a57b938337095fbd35372
SHA256: eb6d22e9390e0d1a79f04a81f926bcd98d496dd65f03535298e1ebf050e4729c

Secure CANcrypt CAN FD Bootloader for NXP LPC546xx

June 15th, 2017 No comments

Together with NXP, the Embedded Systems Academy implements a secure CAN FD bootloader based on the CANcrypt security protocols. The bootloader will be available to users of the LPC546xx as free download. It is a “secondary bootloader”, meaning that it only provides security for the added bootloading channel, in this case the CAN FD interface. Someone with physical access to the LPC546xx will always be able to use the primary, on-chip bootloader to re-flash the device with any code.

The security system of the bootloader uses two security levels, each based on a symmetric key (default 128bit, up to 1024bit optional).

  1. On the CAN FD communication level, the CANcrypt protocol ( is used to ensure that only an authorized communication partner can activate the bootloader, erase the flash memory and send new code to the LPC546xx. The CANcrypt connection key used for this level is generated by the system builder or integrator that initially assembles the entire system.
  2. On the file transfer level, the file containing the new code to be loaded is encrypted using an encryption and authentication method based on a code protection key that gets programmed into the LPC546xx at the same time when the bootloader is installed (typically at manufacturer end-of-line assembly and test).
Secure bootloader security levels

Figure: Secure bootloader security levels

These two levels ensure a separation of the security features between manufacturer and system integrator/builder or service technician. Only an authorized technician will be able to connect his diagnostic device or software to the bootloader. But at this security level alone it will not be possible to generate authorized firmware, that requires an additional key only known to the manufacturer.

If you want to learn more about this bootloader, register now for the webinar (Thursday, June 29, 5:00 PM – 6:00 PM CEST) on the NXP website at:

The version for free download is a binary only and will use a pre-selected cipher algorithms, fixed default configuration for parameters like CAN FD bit rates, CAN IDs and timings and timeouts used. The full source code is available from Embedded Systems Academy, giving users full control over all configurations and cipher algorithms used.

What CAN you accomplish with CAN-FD? – A Two-Part Webinar Series

May 17th, 2017 No comments

NXP offers a Two-Part Webinar based on the LPC54000 series about CAN-FD and secure bootloaders.

Part I: “An intro to CAN-FD” will be held on Thursday, May 25, 5:00 PM – 6:00 PM CEST.
In this webinar CAN bus expert Andy Ayre from Embedded Systems Academy will give you a technical overview of the improvements and benefits of CAN-FD over classic CAN, and how to specifically leverage this new technology on the LPC54618 MCU.

Part II: “CAN stack porting and secure bootloaders” will be held on Thursday, June 29, 5:00 PM – 6:00 PM CEST.
Experts from Embedded Systems Academy explain the requirements for an implementation of secure and non-secure bootloaders in CAN and CAN-FD systems – leveraging the LPC546xx MCU family as an example.

Register now for these events on the NXP website at:


Impressions from the international CAN Conference iCC 2015

October 28th, 2015 No comments

The 15th international CAN Conference took place in Vienna on October 27th and 28th 2015. On two days, a total of 23 papers were presented. Topics included current application examples, security and IoT (Internet of Things)  issues and “everything” CAN FD (Flexible Data Rate) related. CAN FD with its increased data rate was the major topic of this conference, many papers were directly related to it.

As CAN FD is not backward compatible to CAN, one of the session topics was migration from CAN to CAN FD. Mixing CAN and CAN FD controllers is only possible if the CAN FD messages are hidden from the CAN controllers as they would generate error frames upon reception. One approach is using partial networking transceivers where traditional CAN controllers are put to sleep during CAN FD communication. After seeing a specific sleep message, transceivers for partial networking can keep the connected CAN controller in sleep mode until a specific wake up message is received – no other message on the network causes a wake-up.

NXP presented a paper about their “FD Shield” transceiver. This transceiver is used to connect legacy CAN controllers to a CAN FD network. The CAN FD traffic is somewhat “shielded” from the CAN controller, only regular CAN traffic passes through but CAN FD messages are blocked as soon as they can be detected. However, there is a side effect: Each CAN FD frame on the network causes a local, not propagated receive error at the CAN controller side. As a result the CAN controller may go error passive. However, as transmits works fine, it will not go bus off and can still be used. Although not perfect, this is a quick and easy solution during a migration phase from CAN to CAN FD.

Another way to quickly connect to CAN FD networks is using Microchips external CAN FD controller using an SPI connection to the host controller. Here designers need to carefully choose the clock rate used on the serial interface side; depending on the CAN FD data rate used the SPI clock might need to be 10 or even 16Mhz. If a CAN FD data rate of 8Mbps is used, then a 10Mhz clock rate on the SPI side is sufficient to handle 100% bus load. However, the host controller of course needs to be able to handle the 10Mhz SPI traffic, too.

Other papers showed how CAN FD can be used in Linux systems, AUTOSAR and J1939, In general, the physical layout for CAN FD networks is not as flexible as it is with regular CAN. With faster bit rates ringing and reflections become more of a problem as they used to be. As usual, if an application tries to get close to the physical limits that a technology provides, more care must be taken when determining the physical layout and terminations.

With more and more CAN networks also getting some “remote access” option or even a gateway/firewall to the Internet, security of CAN networks suddenly becomes more important. In the past, CAN networks could be regarded as “closed” (inside a machinery, no remote access) so no precautions were taken in regards to security. Once a CAN network goes “online”, even if it is by the means of some firewall and even if it is only part-time, the entire security concept needs to be re-evaluated. Recent car hacks have shown that once hackers are past the firewall, they can do “anything” because there is no security layer in the CAN network.

Papers from Robert Bosch GmbH and the CiA showed some possible options to add encryption also to CAN communication, however, that directly has an impact on debugging and testing. If communication between two ECUs is secure, how do we monitor or debug it? So the debugger/tester/logger needs to part of this equation, too. It will be interesting to see where this goes, will at some point security be added to all CAN communication or will it be limit to “relevant” transmissions like commands that actually do something to the system?

Once the papers are added to the CiA’s server system, they will be available for download.

Categories: CAN, CANopen Tags: , ,

Impressions from the Embedded World 2015

March 2nd, 2015 No comments

With about 900 exhibitors the Embedded World reached a size where it is impossible to “see it all”. Yes, you can still walk by all booths in a day, but you might easily miss hidden highlights. It was quite obvious that IoT – the Internet of Things – is a current hype. To me this is quite astonishing as already some 10+ years ago we built an “Embedded Internet Demo” – at that time based on a Philips 8051 with a dial-up modem connected. The main difference between now and then is that now smart phones are widely spread and we are “always online” and now can access our embedded devices “at any time”. Among the visitors one could recognize a lot of skepticism for what exactly we really need the IoT, other then it being hip and cool to be able to control “everything” with our smart phone.

An unusual approach to get remote access to embedded applications was shown by Raisonance ( – they have a miniature NFC or Bluetooth module that connect to the JTAG/SWD debug port of an application. So it can be added to any application with debug port, sometimes even without the need to re-compile the code, if you have the knowledge where in memory the variables are that you want to have remote access to. A great tool to get started with IoT without requiring a re-design of existing hardware.

At the CiA (CAN in Automation) booth a CAN FD demo integrated devices and tools from multiple vendors. CAN FD (Flexible Data) allows higher bit rates and longer contents (up to 64 bytes) of the data frame. Especially bootloader applications and other software update features benefit from the higher data throughput. For such applications it seems to be possible to increase the effective data throughout 8 fold easily, potentially even more.

We at ESAcademy further enhanced our portfolio of CANopen Diag products. There is now a second hardware, based on PEAK’s mini Display, that offers a subset of the diagnostic features provided at a price point of well below 1000 Euro. The CANopen Test Machine System part of the CANopen Diag now allows to create tests based on MS Visio graphs. The transitions in a state diagram can be used to transmit or receive a CAN/CANopen message or to influence/set/test/query variables or timers. More details and examples will be published shortly.