Hairgap

Basic protocol to send files using the hairgap binary. The goal is to send random files through a unidirectionnal data-diode using UDP connections.

By default, hairgap can only send a file, without its name nor metadata. This Python library implements a basic protocol to send complete directories with checksums.

This protocol is customizable and the sender can add some attributes (a Dict[str, str]) to each transfer.

• We assume that the hairgap binary is installed and in the PATH environment variable.
• The MAC adress of the destination must be known from the sender machine. You can inject this information into the ARP cache of the sender machine:

DESTINATION_IP="the IP address of the destination machine"
DESTINATION_MAC="the MAC address of the destination machine"
arp -s ${DESTINATION_IP} ${DESTINATION_MAC}

First, you must start the receiver on the destination side:

python3 -m pip install hairgap

DESTINATION_IP="the IP address of the destination machine"
pyhairgap receive ${DESTINATION_IP} directory/

Then you can send directories:

python3 -m pip install hairgap

DESTINATION_IP="the IP address of the destination machine"
pyhairgap send ${DESTINATION_IP} directory/

Hairgap binaries

You need to compile hairgap binaires yourself since no official package exists. However, a Python package (hairgap-binaries) has been created to distribute precompiled binaries for Linux x86_64. This package is automatically detected and used.

python3 -m pip install hairgap-binaries