这个是我/etc/apt/sources.list的更新源：
1 deb http://http.kali.org/kali kali-rolling main contrib non-free 2 deb http://old.kali.org/kali sana main non-free contrib
配置好之后apt-get update报错如下：
1 root@kali:~# apt-get update 2 Get:1 http://old.kali.org/kali sana InRelease [20.3 kB] 3 Get:2 http://mirrors.neusoft.edu.cn/kali kali-rolling InRelease [30.5 kB] 4 Err:1 http://old.kali.org/kali sana InRelease 5 The following signatures were invalid: EXPKEYSIG ED444FF07D8D0BF6 Kali Linux Repository <devel@kali.org> 6 Err:2 http://mirrors.neusoft.edu.cn/kali kali-rolling InRelease 7 The following signatures were invalid: EXPKEYSIG ED444FF07D8D0BF6 Kali Linux Repository <devel@kali.org> 8 Reading package lists... Done 9 W: GPG error: http://old.kali.org/kali sana InRelease: The following signatures were invalid: EXPKEYSIG ED444FF07D8D0BF6 Kali Linux Repository <devel@kali.org> 10 E: The repository 'http://old.kali.org/kali sana InRelease' is not signed. 11 N: Updating from such a repository can't be done securely, and is therefore disabled by default. 12 N: See apt-secure(8) manpage for repository creation and user configuration details. 13 W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.neusoft.edu.cn/kali kali-rolling InRelease: The following signatures were invalid: EXPKEYSIG ED444FF07D8D0BF6 Kali Linux Repository <devel@kali.org>
经google查找解决方式，得到国外大佬给出的解决方案：
https://forums.kali.org/showthread.php?38858-apt-get-update-GPG-error-key-expired
1 apt-key adv --keyserver hkp://keys.gnupg.net --recv-keys 7D8D0BF6
再次apt-get update就没问题了