Configure every saved WiFi connection in NetworkManager with a spoofed MAC # address, seeded from the UUID of the connection and the date

randomize-mac-addresses

#!/bin/sh

# /etc/NetworkManager/dispatcher.d/pre-up.d/randomize-mac-addresses

# Configure every saved WiFi connection in NetworkManager with a spoofed MAC
# address, seeded from the UUID of the connection and the date plus the hour eg:
# 'c31bbcc4-d6ad-11e7-9a5a-e7e1491a7e20-2017-11-20-09'

# This makes your MAC difficult to track across WiFi providers, and
# for one provider to track across days.

export PATH=$PATH:/usr/bin:/bin

LOG_FILE=/var/log/randomize-mac-addresses

echo "$(date): $*" > ${LOG_FILE}

WIFI_UUIDS=$(nmcli --fields type,name, uuid connection show | grep wifi | grep -v BYOD | awk '{print $3}')

for UUID in ${WIFI_UUIDS}
do
    UUID_HASH=$(echo "${UUID}-$(date +"%F")" | md5sum)

    OLD_RND_MAC=$(nmcli connection show uuid ${UUID} | grep cloned-mac-address | awk '{print $2}')
    NEW_RND_MAC="02:$(echo -n ${UUID_HASH} | sed 's/^\(..\)\(..\)\(..\)\(..\)\(..\).*$/\1:\2:\3:\4:\5/')"

    LOGLINE="Connection ${UUID} changed MAC from ${OLD_RND_MAC} to ${NEW_RND_MAC}"
    CMD="nmcli connection modify ${UUID} wifi.cloned-mac-address ${NEW_RND_MAC}"

    echo "$LOGLINE" >> ${LOG_FILE}
    $CMD &
done

wait