CharizHard

A cutting-edge hardware solution designed to secure data exchanges and protect devices from hardware-based threats.

Features

This USB dongle features dual interfaces:

• USB Interface: The laptop detects the dongle as an Ethernet device, ensuring that the laptop’s internal network hardware remains isolated and protected.

• Wi-Fi Baseband Interface: This interface connects the laptop to a Wi-Fi network, while the dongle transparently manages a VPN connection to a secure VPN server, ensuring that all communications are encrypted and secure.

The primary goals of CharizHard are to:

• Secure communications: Encrypt and protect all data exchanged between the laptop and the VPN server, typically managed by the user’s company.

• Prevent hardware attacks: Shield the laptop’s hardware network interface, reducing exposure to physical attacks and vulnerabilities.

With CharizHard, users can trust that their data and devices are secure, providing peace of mind in an increasingly connected world.

Requirements

This project uses the esp-idf version v5.2.3 for the standard esp32.

Drivers for the esp32 can be found on the esp-idf website.

This project requires Rust, Python and the standard C toolchain. The standard C toolchain as well as git are assumed to already be installed by the user. If not, the user is likely on Windows and following the msys2 tutorial here should make everything work out of the box: Install msys2.

Installing git can then be done using the following command in a ucrt64 shell.

pacman -Syu && pacman -S git

The C:\msys64\ucrt64\bin folder must be added to the PATH environment variable.

Windows

Installing Rust:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Installing Python:

https://www.python.org/downloads/release/python-3125/

Linux

Installing Rust:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Installing Python: Using your favorite package manager, install python3.12 python3-pip or python312 and python-pip depending on distribution.

Ensure the version is 3.12.5 as more recent versions have proved unstable.

Installing

On windows, this project needs to be cloned in your root directory, as the esp32 build process cannot handle long paths.

cd /

Install espup to get the esp toolchain required to compile on the xtensa-esp32-espidf architecture.

cargo install espup

Install the toolchain and follow any additional instruction written to the standard output.

Do not forget to run the export.bat on Windows or ./export.sh on Linux situated in .embuild/esp-idf/v5.2.3/. Otherwise you will not have access to espefuse and espsecure

espup install

Clone the repository then cd inside. Note that the name of the folder must be short and located at the root of your filesystem if you are on a Windows distribution. Here, we use chhard.

git clone https://github.com/indexds/charizhard chhard && cd chhard

Install the cargo-make binary to make the build process less of a chore. If not possible, the project can be compiled by running the commands found in Makefile.toml manually.

You're also going to need espflash and ldproxy as dependencies.

cargo install cargo-make cargo-espflash ldproxy

Then you're gonna need:

pip install esptool

All that remains is to install all remaining dependencies, build the project and flash the esp32 with:

cargo [flash|f]

Monitoring

To get logs to stdout, use:

cargo [monitor|m]

Menuconfig

The menuconfig tool is used to modify the sdkconfig file which dictates what is and isn't compiled into the final binary.

To access the menuconfig tool, install the following dependencies:

cargo install cargo-pio

pip install --upgrade platformio

Then, run:

cargo pio installpio

You can now access the menuconfig tool using:

cargo [pio espidf menuconfig | c]

The tool will first download the xtensa-esp-elf toolchain which may take a while.

Troubleshooting

• If the compilation process fails to find libclang.dll or clang.dll, create an environment variable LIBCLANG_PATH with the path to your libclang.dll as such:

Linux

~/.rustup/toolchains/esp/xtensa-esp32-elf-clang/esp-clang/bin/

Windows

%USERPROFILE%\.rustup\toolchains\esp\xtensa-esp32-elf-clang\esp-clang\bin\

• If the program fails to connect to the esp32 upon flashing, the esp32 must be rebooted (by grounding then releasing the EN pin) while the BOOT pin is grounded. This puts the esp32 in bootloader mode. Firmware should then start flashing.

• If the program fails for any reason related to Python, check that the version used by the program is a 3.12.x as Python >=3.13 is not currently supported.

• Should the program have multiple dependency failures, try running cargo clean then rebuilding the project properly with cargo [flash|f].

• If you cannot move the selection while in menuconfig inside an integrated terminal like the one provided by vscode, the correct bindings are J/K.

License

GNU GPL-3.0