Duo Unix Package Debian 9 - apt update failed

#1

Hello,

In order to install DUO UNIX with packages for Debian 9, I followed the information given in Duo Unix - 2FA for SSH with PAM Support (pam_duo) | Duo Security
But when you try to run apt update, the following errors appear:

# apt-key list
pub dsa1024 2013-09-05 [SC] [expire : 2020-08-22]
30BF E024 2B19 592E B122 211D 1CC9 1FC6 15D3 2EFC
uid [ inconnue] Duo Security Package Signing dev@duosecurity.com
sub elg4096 2013-09-05 [E] [expire : 2020-08-22]

# apt update

Ign :9 http://pkg.duosecurity.com/Debian stretch InRelease
Réception de :11 http://pkg.duosecurity.com/Debian stretch Release [2 046 B]
Réception de :12 http://pkg.duosecurity.com/Debian stretch Release.gpg [72 B]
Ign :12 http://pkg.duosecurity.com/Debian stretch Release.gpg
W: Erreur de GPG : http://pkg.duosecurity.com/Debian stretch Release : Detached signature file ‘/var/lib/■■■■_Debian_dists_stretch_Release.gpg’ is in unsupported binary format
E: Repository http://pkg.duosecurity.com/Debian stretch Release is not signed.

Has anyone ever had a similar issue?
If so, how did you fix it?
Thank you for your help in solving this problem.

#2

I just ran a quick test of this and it worked okay for me so my hunch is it might be something going on locally.
The expiration looks good on your key as well, but maybe running
curl -s https://duo.com/APT-GPG-KEY-DUO | sudo apt-key add -
followed by a sudo apt-get update
would be worthwhile just to double check.

#3

Thank you for your answer,
but i retry and same issue:

curl -s https://duo.com/APT-GPG-KEY-DUO | sudo apt-key add -
OK

# apt-key list
/etc/apt/trusted.gpg
--------------------
pub   dsa1024 2013-09-05 [SC] [expire : 2020-08-22]
      30BF E024 2B19 592E B122  211D 1CC9 1FC6 15D3 2EFC
uid          [ inconnue] Duo Security Package Signing <dev@duosecurity.com>
sub   elg4096 2013-09-05 [E] [expire : 2020-08-22]

# apt-get update
W: Erreur de GPG : http://pkg.duosecurity.com/Debian stretch Release : Detached signature file '/var/lib/■■■■_Debian_dists_stretch_Release.gpg' is in unsupported binary format
E: Le dépôt http://pkg.duosecurity.com/Debian stretch Release n'est pas signé.

Perhaps because i used Debian “Buster” and not “Stretch”?
I don’t really understood why that’s failed.

If no idea then I will try with source files and compilation.