apt-get update ne fonctionne pas: erreurs de signature / vérification

Quand je cours apt-get updateje reçois

Ign:1 http://dl.google.com/linux/musicmanager/deb stable InRelease
Ign:2 http://archive-4.kali.org/kali kali-rolling InRelease                
Hit:3 http://archive-4.kali.org/kali-security sana/updates InRelease
0% [3 InRelease gpgv 11.9 kB] [Waiting for headers] [Waiting for headers]Couldn't create tempfiles for splitting up /var/lib/apt/lists/security.kali.org_kali-seErr:3 http://archive-4.kali.org/kali-security sana/updates InRelease     
  Could not execute 'apt-key' to verify signature (is gnupg installed?)
Hit:4 http://archive-4.kali.org/kali sana InRelease                      
0% [4 InRelease gpgv 20.3 kB] [Waiting for headers]Couldn't create tempfiles forErr:4 http://archive-4.kali.org/kali sana InRelease_dists_sana_InRelease
  Could not execute 'apt-key' to verify signature (is gnupg installed?)
Get:5 http://archive-4.kali.org/kali kali-rolling Release [23.7 kB]
Get:6 http://archive-4.kali.org/kali kali-rolling Release.gpg [819 B]          
0% [6 Release.gpg gpgv 23.7 kB]                                    3,846 B/s 0smktemp: failed to create directory via template '/tmp/tmp.XXXXXXXXXX': Permission denied
Err:6 http://archive-4.kali.org/kali kali-rolling Release.gpg                  
  At least one invalid signature was encountered.
Hit:7 http://dl.google.com/linux/musicmanager/deb stable Release               
80% [Release.gpg gpgv 1,345 B]mktemp: failed to create directory via template '/tmp/tmp.XXXXXXXXXX': Permission denied
Err:8 http://dl.google.com/linux/musicmanager/deb stable Release.gpg
  At least one invalid signature was encountered.
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://archive-4.kali.org/kali-security sana/updates InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://archive-4.kali.org/kali sana InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: GPG error: http://archive-4.kali.org/kali kali-rolling Release: At least one invalid signature was encountered.
E: The repository 'http://http.kali.org/kali kali-rolling Release' is no longer 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: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://dl.google.com/linux/musicmanager/deb stable Release: At least one invalid signature was encountered.

Je ne sais pas du tout comment cela s'est passé ni comment y remédier. J'ai gnupg, gnupg-agent, gnupg-pkcs11-scd, gnupg2, gnupg-curl, gnupg-pkcs11-scd-dbg installé.

Effacer le cache APT et le régénérer:

sudo apt-get clean
sudo mv /var/lib/apt/lists /tmp
sudo mkdir -p /var/lib/apt/lists/partial
sudo apt-get clean
sudo apt-get update

Peut-être y a-t-il un lien ou un fichier non valide dans le répertoire /etc/apt/trusted.gpg.d/

Vérifiez que le répertoire contient des fichiers et des liens valides, par exemple:

# ls -L /etc/apt/trusted.gpg.d/* > /dev/null
ls: cannot access '/etc/apt/trusted.gpg.d/live-net-archive-keyring.gpg': No such file or directory

Par conséquent, recherchez le package qui doit contenir le fichier

# dpkg -S /etc/apt/trusted.gpg.d/live-net-archive-keyring.gpg
live-net-archive-keyring: /etc/apt/trusted.gpg.d/live-net-archive-keyring.gpg

et prenez certaines des actions suivantes:

le réinstaller

# aptitude reinstall live-net-archive-keyring

ou réinstaller tous les trousseaux installés

# aptitude reinstall $(dpkg -l '*keyring' | awk '$1 == "ii" {print $2}')
The following packages will be REINSTALLED:
debian-archive-keyring gnome-keyring live-net-archive-keyring siduction-archive-keyring 

ou supprimer le lien ou le fichier non valide

# rm /etc/apt/trusted.gpg.d/live-net-archive-keyring.gpg 

Essayer chown root:root /tmp chmod 1777 /tmp