+++ title = 'Problems with apt-keys on my hotspots' summary = '''For some reasons apt wasn't able to verify the repositories signing keys on my Raspberry-Pi based hotspots and this is how I fixed it.''' date = '2023-08-05T08:36:38+02:00' lastmod = '2023-08-05T07:35:46+0000' categories = [ 'amateur-radio' ] tags = [ 'hotspot', 'pistar', 'raspberry-pi' ] +++ It is about a few times a year when something is broken on a linux system. Today (actually yesterday but I couldn't stay up much longer and I was already fed up with this sh\*\*) I upgraded my two raspberry-pi based hotspots and realized when apt couldn't verify the repositories signing keys because of missing keys. This happens usually on *any linux distribution* at least *once a year*. So it shouldn't be a big deal but it consumes time and I usually have to look into manpages and/or online help again because I already forgot how I fixed it the last time... Today, I write it down below. ## What the error looks like When running `sudo apt update`: ```console $ sudo apt update Get:1 http://httpredir.debian.org/debian bullseye-backports InRelease [49,0 kB] Get:2 http://security.debian.org/debian-security bullseye-security InRelease [48,4 kB] Get:3 http://deb.debian.org/debian bullseye-updates InRelease [44,1 kB] Hit:4 http://archive.raspberrypi.org/debian bullseye InRelease Get:5 http://raspbian.raspberrypi.org/raspbian bullseye InRelease [15,0 kB] Err:1 http://httpredir.debian.org/debian bullseye-backports InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 0E98404D386FA1D9 NO_PUBKEY 6ED0E7B82643E131 Err:2 http://security.debian.org/debian-security bullseye-security InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 112695A0E562B32A NO_PUBKEY 54404762BBB6E853 Err:3 http://deb.debian.org/debian bullseye-updates InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 0E98404D386FA1D9 NO_PUBKEY 6ED0E7B82643E131 Reading package lists... Done W: GPG error: http://httpredir.debian.org/debian bullseye-backports InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 0E98404D386FA1D9 NO_PUBKEY 6ED0E7B82643E131 E: The repository 'http://httpredir.debian.org/debian bullseye-backports InRelease' 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. W: GPG error: http://security.debian.org/debian-security bullseye-security InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 112695A0E562B32A NO_PUBKEY 54404762BBB6E853 E: The repository 'http://security.debian.org/debian-security bullseye-security InRelease' 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. W: GPG error: http://deb.debian.org/debian bullseye-updates InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 0E98404D386FA1D9 NO_PUBKEY 6ED0E7B82643E131 E: The repository 'http://deb.debian.org/debian bullseye-updates InRelease' 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. ``` ## Obtain the keys ```console $ gpg --keyserver hkps://keyserver.ubuntu.com --recv-keys 0E98404D386FA1D9 6ED0E7B82643E131 112695A0E562B32A 54404762BBB6E853 gpg: keybox '/home/pi-star/.gnupg/pubring.kbx' created gpg: /home/pi-star/.gnupg/trustdb.gpg: trustdb created gpg: key A48449044AAD5C5D: public key "Debian Security Archive Automatic Signing Key (11/bullseye) " imported gpg: key 4DFAB270CAA96DFA: public key "Debian Security Archive Automatic Signing Key (10/buster) " imported gpg: key B7C5D7D6350947F8: public key "Debian Archive Automatic Signing Key (12/bookworm) " imported gpg: key 73A4F27B8DD47936: public key "Debian Archive Automatic Signing Key (11/bullseye) " imported gpg: Total number processed: 4 gpg: imported: 4 ``` ## Import the keys This still works, though, there is a [better method](https://stackoverflow.com/a/71384057) for future encounters. ```console $ gpg -a --export 0E98404D386FA1D9 6ED0E7B82643E131 112695A0E562B32A 54404762BBB6E853 | sudo apt-key add - Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)). OK ``` ## The resulting update process ```console $ sudo apt update Get:1 http://httpredir.debian.org/debian bullseye-backports InRelease [49,0 kB] Hit:2 http://raspbian.raspberrypi.org/raspbian bullseye InRelease Get:3 http://security.debian.org/debian-security bullseye-security InRelease [48,4 kB] Get:4 http://deb.debian.org/debian bullseye-updates InRelease [44,1 kB] Hit:5 http://archive.raspberrypi.org/debian bullseye InRelease Get:6 http://httpredir.debian.org/debian bullseye-backports/main armhf Packages [415 kB] Get:7 http://httpredir.debian.org/debian bullseye-backports/main Translation-en [353 kB] Get:8 http://security.debian.org/debian-security bullseye-security/main armhf Packages [248 kB] Get:9 http://security.debian.org/debian-security bullseye-security/main Translation-en [164 kB] Get:10 http://httpredir.debian.org/debian bullseye-backports/contrib armhf Packages [4.680 B] Get:11 http://httpredir.debian.org/debian bullseye-backports/contrib Translation-en [5.984 B] Get:12 http://httpredir.debian.org/debian bullseye-backports/non-free armhf Packages [9.072 B] Get:13 http://httpredir.debian.org/debian bullseye-backports/non-free Translation-en [27,7 kB] Get:14 http://security.debian.org/debian-security bullseye-security/non-free Translation-en [464 B] Get:15 http://deb.debian.org/debian bullseye-updates/main armhf Packages [14,7 kB] Get:16 http://deb.debian.org/debian bullseye-updates/main Translation-en [9.964 B] Fetched 1.253 kB in 4s (282 kB/s) Reading package lists... Done Building dependency tree... Done Reading state information... Done All packages are up to date. ``` ## Another way (quicker) but untested This should also work like the above (until EOL of `apt-key`). ```console $ apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 0E98404D386FA1D9 6ED0E7B82643E131 112695A0E562B32A 54404762BBB6E853 ``` ## Final words I got that feeling: the next time I'd need this, `apt-key` will not work and got fully replaced by signing keys in /etc/apt/keyrings... Inspired by this post: As the default keyserver strips user-ids they cannot imported without the `--keyserver` switch.