how to install debian package from unsigned repository

Question

Trying to install Debian package to Debian 9 from unsigned repository:

# apt-get --allow-unauthenticated update
Get:1 http://files.freeswitch.org/repo/deb/freeswitch-1.8 stretch InRelease [3,196 B]
Hit:2 http://security.debian.org/debian-security stretch/updates InRelease
Ign:1 http://files.freeswitch.org/repo/deb/freeswitch-1.8 stretch InRelease
Ign:3 http://debianmirror.nkn.in/debian stretch InRelease
Hit:4 http://debianmirror.nkn.in/debian stretch Release
Fetched 3,196 B in 1s (1,940 B/s)
Reading package lists... Done
W: GPG error: http://files.freeswitch.org/repo/deb/freeswitch-1.8 stretch InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY BD3189F5A2B57698
W: The repository 'http://files.freeswitch.org/repo/deb/freeswitch-1.8 stretch InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.

But I need it. How can I do it? Thanx!

Answer 1

In the sources.list entry for the untrusted repository, you can add "[trusted=yes]" (with the square brackets) between the first two elements of the entry, as in deb [trusted=yes] http://...

This will turn the error into a warning, as it has been default in past Debian releases, without having to completely disable signature verification