How do I fix the GPG error “NO_PUBKEY”?

Question

I added some extra repositories with the Software Sources program. But when I reload the package database, I get an error like the following:

GPG error [...] NO_PUBKEY [...]

I know I can fix it using apt-key in a terminal, according to the official Ubuntu documentation. But I would have liked to do it graphically. Is there a mean not to open a terminal?

Answer 1

You need to get and import the key.

To get the key from a PPA, visit the PPA's Launchpad page. On every PPA page at Launchpad you will find this link (2), after clicking on 'Technical details about this PPA' (1):

Follow it and click on the key ID link (3):

Save the page, this is your key file.

---

Now it's time to import it:

• Applications > Sofware Center,
• Edit > Sofware sources...,
• Enter your password,
• Go to the 'Authentication' tab and click on 'Import Key File...', finally
• Select the saved key file and click on 'Ok'.

That's it.

Answer 2

Execute the following commands in terminal

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 8BAF9A6F

and then update

sudo apt-get update

Answer 3

There is a tiny script packaged in the WebUpd8 PPA which I'll link as a single .deb download so you don't have to add the whole PPA - which automatically imports all missing GPG keys.

Download and install Launchpad-getkeys (ignore the ~natty in its version, it works with all Ubuntu versions from Karmic all the way to Oneiric). Once installed, open a terminal and type:

sudo launchpad-getkeys

If you're behind a proxy, things are a bit more complicated so see this for more info

Answer 4

It happens because you don't have a suitable public key for a repository.

To solve this problem use this command:

gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv 9BDB3D89CE49EC21

Which retrieves the key from ubuntu key server and then this:

gpg --export --armor 9BDB3D89CE49EC21 | sudo apt-key add -

Which adds the key to apt trusted keys. This will solve you problem.

The solution can be found here & here.

Answer 5

More generally, the following method should work for every repository. First of all search, with eventual help of a search engine, for a text on the program provider's website looking like the following:

-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.4.1 (GNU/Linux)
[...]
-----END PGP PUBLIC KEY BLOCK-----

Such a text is for example displayed on http://deb.opera.com. Copy the passage, paste it in an empty file that you create on your desktop. This results in the key file.

Then continue with the importation of the key:

• Applications > Sofware Center
• Edit > Sofware sources..., enter password
• Authentication tab, click on 'Import Key File...'
• Select the saved key file and click on 'Ok'.

You may now remove the previously created key file.