Add new key to APT AKA tell APT to trust given key

2015-04-30 Linux

On one of my desktop boxes I recently got this message when I wanted to update it via apt:

Fetched 1448 B in 8s (180 B/s)
Reading package lists... Done
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used.
GPG error: http://xxxxxxx ./ Release: The following signatures couldn't be verified because
the public key is not available: NO_PUBKEY 0000000000

The solution is very straightforward, but let’s write it down here since I always forget how to do it. Here it is:

gpg --keyserver subkeys.pgp.net --recv-keys keyId
gpg -a --export keyId | sudo apt-key add -

Of course you will need to replace keyId with the real GPG key which is missing/unknown to APT.

Additional resources - SecureApt Debian wiki page

–robert