KEYEXPIRED on Opensuse repository

Question

Running Ubuntu 16.04.4 LTS.

On running sudo apt update, the final lines are as follows:

W: GPG error: http://download.opensuse.org/repositories/home:/osmc/xUbuntu_16.04  Release: The following signatures were invalid: KEYEXPIRED 1482381670
E: The repository 'http://download.opensuse.org/repositories/home:/osmc/xUbuntu_16.04  Release' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

apt-key list shows one key expired:

pub   2048R/70F1BBEA 2014-10-14 [expired: 2016-12-22]
uid                  home:osmc OBS Project <home:osmc@build.opensuse.org>

(For some reason, apt-key list | grep “expired:” returns nothing however.)

Attempting to update this key does not change anything:

$ apt-key adv --keyserver keys.gnupg.net --recv-keys 70F1BBEA
Executing: /tmp/tmp.pOcDAzqSkJ/gpg.1.sh --keyserver
keys.gnupg.net
--recv-keys
70F1BBEA
gpg: requesting key 70F1BBEA from hkp server keys.gnupg.net
gpg: key 70F1BBEA: "home:osmc OBS Project <home:osmc@build.opensuse.org>" not changed
gpg: Total number processed: 1
gpg:              unchanged: 1

I also tried running Y PPA Manager and "Try to import all missing GPG keys" but the result was the same.

I'm guessing perhaps I'm running an out-of-date version of Opensuse and need to change it, but I'm uncertain of what it is and how to do this correctly.

Answer 1

After adding a third party repository to a /etc/apt/sources.list.d/* file or /etc/apt/sources.list, you need to make sure the corresponding gpg key is inserted into the apt keystore.

wget http://download.opensuse.org/repositories/home:/osmc/xUbuntu_16.04/Release.key -O - | sudo apt-key add -    
sudo apt update  

---

If that doesn't work because the key really expired, remove the error and warning messages. Open /etc/apt/sources.list.d/osmc-installer.list and add a hash character ( # ) at the beginning of the lines before deb to turn them into comments.

sudo nano /etc/apt/sources.list.d/osmc-installer.list  

Press the keyboard combination Ctrl+O and after that press Enter to save the file being edited. Press the keyboard combination Ctrl+X to exit nano.

Update your list of available software packages.

sudo apt update