add Kali Linux repositories in Ubuntu

$ sudo gedit /etc/apt/sources.list
deb http://ppa.launchpad.net/wagungs/kali-linux/ubuntu raring main
deb http://ppa.launchpad.net/wagungs/kali-linux1/ubuntu raring main
deb http://ppa.launchpad.net/wagungs/kali-linux2/ubuntu raring main

$ nano kali.pgp
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: SKS 1.1.4
Comment: Hostname: keyserver.ubuntu.com

mI0ET324YwEEANbSlISrOlAGjxgFRxiN6jk0JIl/vxQ8lapRdxZ4DHDAQdXbX4AuigMBkP5e
sOxhMpDnkgMRtEVpaBMdQheA0/431pPQYqkr3jdeZw5JS5opiyJ4qr/QrcoSFHSluEkWkbZ6
RYOkA25vW31KK2FB2LQVRYk580llXAVgIUznm2ATABEBAAG0GExhdW5jaHBhZCBQUEEgZm9y
IHdhZ3VuZ4i4BBMBAgAiBQJPfbhjAhsDBgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAAKCRAb
IuuNj9/bVxabBADSGN8cp+hqkdZqwq263wdz/UGsiuB1bCrH06/HznC/ZC5rjfH3aQ1Dwwag
zYCrSD3c0cKNAqD10009N76RMlzZBH8kKL9khH3zPL/k4/lYuVP7y6NKFbBsnawEUc0mWcCa
mH4ScTdWWPXP/mOQiUUjnQ1bZhzpcbQOb+hEUAqExg==
=fJ+8
-----END PGP PUBLIC KEY BLOCK-----

$ sudo apt-key add kali.pgp

$ sudo apt-get update