Firmware Verification

This document explains how to check whether your Mycelium Entropy device contains only genuine firmware.

This procedure guarantees malware detection only if the potential compomise happened before the 7th of April 2015.

  1. Hold the button down while inserting the device into your computer.

  2. The device’s LED will pulsate slowly.

  3. Your computer should detect a USB disk labelled ME-CONFIG.

  4. Download and copy verify.tsk to ME-CONFIG.

  5. Instruct your computer to eject/unmount/safely remove ME-CONFIG, like you would a regular USB flash stick.

  6. Briefly press the button on the device.

  7. The light on the device will blink rapidly for about 16 seconds.

  8. If the firmware is genuine, the two LEDs will blink alternately (not too fast, around two times a second).
    Any other indication means that your device may have been compromised.

After that, you can unplug your device.

The firmware in your device is not modified by this procedure.

This procedure does not involve re-programming of any existing firmware. The verification tool will run entirely in the volatile RAM, checking hashes and signatures of all firmware components.

This tool can also dump the actual contents of your Entropy’s firmware. After verification, the device will create a disk labelled FIRMWARE with three files on it.

Why is this procedure potentially ineffective against future compromises?

Your device’s firmware is used to run the verification tool (verify.tsk). Once this document is published, there is small risk that a clever attacker may adapt his/her forged firmware to fake the tool’s blinking and the FIRMWARE disk.

Firmware Hashes

This section is purely informational. The LED-based verification explained above is fully sufficient to determine whether your device has been compromised or not.

The firmware is stored in three sections of Mycelium Entropy flash. Two of them are slightly larger than the corresponding firmware parts. The verification tool dumps entire sections, where firmware is padded at the end (usually with FF). The hashes below take this padding into account.

The hash of the verification tool is also included. Note that it will not appear on the FIRMWARE disk.

File SHA-1 hash Description

boot.bin

6bf1a0305fe76ac81ce5f5cb5fa874312f10ca6b

Bootloader.

firmware.bin

71ac8668438594babc77b4f2d8de6f2ec0de77e5 or
d2b70565164c63890eccea183d01674574e145db or
09ea40c183a23de5ec42ea01c1f38f727815fc81

Main firmware.

bip39.bin

7f33cd6922b414f14ea4107e7ca88c18fedecf1f

BIP-39 word list, used for HD wallets.

verify.tsk

386710390f7dbeccf57df5bd1dfd81f02ffa4a5c

Firmware verification tool.

Source Code

The source code of the firmware verification tool (verify.tsk) is available in the Mycelium Entropy repository at github.com/mycelium-com/entropy/tree/master/verify.

The .tsk extension is a reference to the RSX-11M operating system, where it denotes an executable program, called a task. In Mycelium Entropy, a task is run once in the RAM until the device is unplugged, and is not stored like regular firmware.