There should be a primitive for repository keys

[5nafu]

Adding a normal repository (i.e. not a ppa ) add-apt-repository will not install the repository key:

REPOSITORY can be either a line that can be added directly to sources.list(5), in the form ppa:/ for adding Personal Package Archives, [...]

In the first form, REPOSITORY will just be appended to /etc/apt/sources.list.

In the second form, ppa:/ will be expanded to the full deb line of the PPA and added into a new file in the /etc/apt/sources.list.d/ directory. The GPG public key of the newly added PPA will also be downloaded and added to apt's keyring.

(emphasis from me)

If we use aptfile to add a repository, there should be an option to add the appropriate key as well.

I would suggest three distinct ways to install a key:

1. installing from a local file
2. installing from an URL (starting with http(s)://)
3. installing with only a keyid (starting with "0x"?)

This probably would be needed for #4 as well.

[josegonzalez]

Sounds good, pull requests welcome!