尝试将debian软件包从未签名的存储库中安装到debian 9：
# 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.
但是我需要它。我该怎么做？thanx！
在"不信任存储库"的列表条目中，您可以在该条目的前两个元素之间添加" [trusted = yes]"（带有方括号）（带有方括号），例如deb [trusted=yes] http://...中
这将使错误变成警告，因为在过去的Debian发行中默认情况下，不必完全禁用签名验证
如果这可以帮助某人，您可以从命令行安装deb文件：
sudo dpkg -i {filename}