NO_PUBKEY 793FEB8BB69735B2. Vivaldi repository GPG error. The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 793FEB8BB69735B2

Debian Bullseye 11 and Ubuntu 22.04 will no longer use apt-key (apt-key deprecated) to manage the list of keys used by apt to authenticate packages. Therefore if you are using debian 10 testing (Bullseye) the standard procedure to import the Vivaldi specific repository key using apt-key will inevitably lead to the title warning.

# Import the Vivaldi repository signing key:
wget -qO- https://repo.vivaldi.com/stable/linux_signing_key.pub | sudo apt-key add -

To avoid the warning we can take the repository key in plain text format, convert it into binary gpg format and add it to the specific apt directory /etc/apt/trusted.gpg.d

curl -fsSL https://repo.vivaldi.com/stable/linux_signing_key.pub | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/bullseye-vivaldi pgdg.gpg > /dev/null


we can split the command into several lines for a better reading: :

curl -fsSL https://repo.vivaldi.com/stable/linux_signing_key.pub | 
gpg --dearmor | 
sudo tee /etc/apt/trusted.gpg.d/bullseye-vivaldi.gpg > 
/dev/null 
  • curl downloads the pub key ( plain text type ) of the Vivaldi apt repository
  • gpg –dearmor create a bynary gpg key
  • tee reads the standard input and writes it both as standard output and to the file ( /etc/apt/trusted.gpg.d/bullseye-vivaldi.gpg )
  • /dev/null avoid displaying the binary key on standard output

The Vivaldi keyring file in the trusted.gpg.d directory ( as desidered )

You can also use wget to download the key

wget --quiet -O - https://repo.vivaldi.com/stable/linux_signing_key.pub | 
gpg --dearmor | 
sudo tee /etc/apt/trusted.gpg.d/bullseye-pgdg.gpg > 
/dev/null 

To view the key in plain text just use the first part of the command:

wget -O- https://repo.vivaldi.com/stable/linux_signing_key.pub

-----BEGIN PGP PUBLIC KEY BLOCK----- mQINBF3Kxh8BEACWWRSZLDXqxs+iqzdFv/rNOaHMmOm740ZLa1rovnJXhJ6ygcyp dP+FNGjqz1s+FfKhrUuhnr8jKzAsIXZrEN/bD3M4qdKmb+I8UCvJqOWoDSXm2Ksl uTgI5AOwgloxYFZ6SIOHe6Du1NDJh5XR/tx+ts8WZ8OstjrqCLADxmh+hGIIzJ+G 
...
...

below it is the warning about Vivaldi’s apt repository in debian bullseys (debian 10 testing) using apt-key. The warning that occurs when launching apt update is reported in full..

...
...
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://repo.vivaldi.com/stable/deb stable Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 793FEB8BB69735B2
W: Failed to fetch http://repo.vivaldi.com/stable/deb/dists/stable/Release.gpg  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 793FEB8BB69735B2
W: Some index files failed to download. They have been ignored, or old ones used instead.
...
...

The warning is also preceded by the following error line :

Err:11 The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 793FEB8BB69735B2

Risorse:

Come determinare il tipo di Web Server in esecuzione su Linux o Windows

[aggiornamento 2012]

In linux è presente il comando curl ( client for URL ) che permette di evidenziare il tipo di web server su cui è in esecuzione un sito web.

$ curl -I  webserver-domain  o ip-number
~$ curl -I www.microsoft.com
HTTP/1.1 200 OK
Cache-Control: private
Content-Length: 0
Server: Microsoft-IIS/8.0
P3P: CP="ALL IND DSP COR ADM CONo CUR CUSo IVAo IVDo PSA PSD TAI TELo OUR SAMo CNT COM INT NAV ONL PHY PRE PUR UNI"
X-AspNet-Version: 2.0.50727
VTag: 791648643500000000
X-Powered-By: ASP.NET
X-Powered-By: ARR/2.5
X-Powered-By: ASP.NET
Date: Sat, 05 Jan 2013 23:01:28 GMT

oppure

~$ curl -I https://mauriziosiagri.wordpress.com/
HTTP/1.1 200 OK
Server: nginx
Date: Sat, 05 Jan 2013 23:09:36 GMT
Content-Type: text/html; charset=UTF-8
Connection: keep-alive
Vary: Accept-Encoding
Vary: Cookie
X-hacker: If you're reading this, you should visit automattic.com/jobs and apply to join the fun, mention this header.
X-Pingback: https://mauriziosiagri.wordpress.com/xmlrpc.php
Link: <http://wp.me/1zOaP>; rel=shortlink

ancora

~$ curl -I http://www.bluehost.com/
HTTP/1.1 200 OK
Date: Sat, 05 Jan 2013 23:13:17 GMT
Server: Apache/2.2.23 (CentOS)
Set-Cookie: r=house%5ENOAFFILIATE%5E-; path=/; expires=Thu, 04-Jul-2013 23:13:17 GMT
Set-Cookie: custid=C840094986302; domain=.bluehost.com; path=/; HttpOnly
Content-length: 19496
Last-Modified: Wed, 02 Jan 2013 22:06:09 GMT
Vary: Accept-Encoding
Content-Type: text/html; charset=ISO-8859-1

.

curl è un client per ottenere  documenti/files da un web server o per mandare documenti ad un server utilizzando diversi protocolli (HTTP, HTTPS, FTP, GOPHER, DICT, TELNET, LDAP or FILE). Non è di tipo interattivo.

– oltre al tradferimento di files
– può comprendere cookies, certificati SSL, proxies
– …