install keepass2

sudo add-apt-repository ppa:jtaylor/keepass
sudo apt-get update && sudo apt-get install keepass2

install firefox addon 'kee'

• download it here
• kee doc here with linux keepass requirement.

download KeePassRPC.plgx plugin

download KeePassRPC.plgx plugin

sudo mkdir /usr/lib/keepass2/plugins
sudo cp 'KeePassRPC.plgx' '/usr/lib/keepass2/plugins/'
sudo apt-get install mono-complete

Restart keepass and firefox

you should be prompt about kee to authorize keepass