I live in Egypt. we have a country specific server here. I used to download everything from there. but when I got to download encryptfs, synaptic said the package could not be authenticated, so I changed the apt mirror to default ubuntu server and the packages could now be authenticated.  Due to the fact that we live in a country with mass surveillance and no laws to protect privacy or human rights, I have been thinking that maybe backdoors were placed in the unauthenticated package. so I have decided to re-download all the unsigned packages from the main ubuntu server, however this doesn't seem to be addressed anywhere.  So, in this regard, how to re-install packages?
1926
Any install that I'm trying through the Software Center is telling me:  Requires installation of untrusted packages: The action would require the installation of packages from not authenticated sources.  I did an apt-get update from the command line, then removed the software sources that the keys were bad from (PPAs I added myself), and unchecked them in the software sources for software center, but to no avail.  I can't install anything from software center anymore - only&gt; from the command line with apt-get. Is uninstalling/installing the only option?  I don't want to break other PPAs that I have. Additional information: Here's a paste from apt-get update: Reading package lists... Done W: GPG error: http://ppa.launchpad.net oneiric Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B725097B3ACC3965 W: GPG error: http://us.archive.ubuntu.com oneiric Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key &lt;ftpmaster@ubuntu.com&gt;  I've tried apt-key update, and there was no effect (two keys unchanged). The output of apt-get update and apt-get upgrade, and the contents of /etc/apt/sources.list, can be found in .
42223
So I am on my college network which requires me to sign in to the browser before I start using the internet. I do so succesfully but on a clean install of Ubuntu, when I try to do sudo apt update, I get the following output:  $ sudo apt update Get:1 http://in.archive.ubuntu.com/ubuntu xenial InRelease [2,847 B] Err:1 http://in.archive.ubuntu.com/ubuntu xenial InRelease                     Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?) Get:2 http://security.ubuntu.com/ubuntu xenial-security InRelease [2,854 B]     Err:2 http://security.ubuntu.com/ubuntu xenial-security InRelease              ... Get:3 http://in.archive.ubuntu.com/ubuntu xenial-updates InRelease [2,855 B]    Err:3 http://in.archive.ubuntu.com/ubuntu xenial-updates InRelease ... Get:4 http://in.archive.ubuntu.com/ubuntu xenial-backports InRelease [2,857 B] Err:4 http://in.archive.ubuntu.com/ubuntu xenial-backports InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?) Fetched 11.4 kB in 0s (18.3 kB/s) Reading package lists... Done E: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/xenial/InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?) ... E: Some index files failed to download. They have been ignored, or old ones used instead.   But when I do wget http://in.archive.ubuntu.com/ubuntu/dists/xenial/InRelease, I get this output success:  2017-04-01 05:34:57  http://in.archive.ubuntu.com/ubuntu/dists/xenial/InRelease Resolving in.archive.ubuntu.com (in.archive.ubuntu.com)... 91.189.88.162, 91.189.88.149, 91.189.88.152, ... Connecting to in.archive.ubuntu.com (in.archive.ubuntu.com)|91.189.88.162|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 246846 (241K) Saving to: ‘InRelease.3’  InRelease.3         100%[===================&gt;] 241.06K   110KB/s    in 2.2s      2017-04-01 05:35:00 (110 KB/s) - ‘InRelease.3’ saved [246846/246846]   Clearly I have internet access from my browser and on wget but when I do sudo apt (or apt-get) update I get this error.  PS: This question is not similar to other threads as their solutions do not seem to work on mine        As I have found out, this problem is happening only to me, not others on the college network. Despite setting up the network according to instructions, this still happens. Any more help would be appreciated  EDIT: So as it turns out, 50% of us in the college are facing this issue, while 50% aren't despite having no issues with the hardware and sudo apt update before the last week. Thanks to @David Foerster for helping me throughout all this time.  As it stands, the issue has been raised to our college's networking department :)
30269
I should begin by mentioning that I am very new to Ubuntu and I am in the process of getting used to it.  Every time I try to update it gives me back an error. I have put it here in my question. Please tell me what to do.   Ign http://archive.ubuntu.com trusty/main Translation-en_IE                     Ign http://archive.ubuntu.com trusty/multiverse Translation-en_IE               Ign http://archive.ubuntu.com trusty/restricted Translation-en_IE               Ign http://archive.ubuntu.com trusty/universe Translation-en_IE                 Err https://download.01.org trusty/main amd64 Packages                            server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none Err https://download.01.org trusty/main i386 Packages   server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none Ign https://download.01.org trusty/main Translation-en_IE Ign https://download.01.org trusty/main Translation-en W: Failed to fetch https://download.01.org/gfx/ubuntu/14.04/main/dists/trusty/main/binary-amd64/Packages  server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none  W: Failed to fetch https://download.01.org/gfx/ubuntu/14.04/main/dists/trusty/main/binary-i386/Packages  server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none  E: Some index files failed to download. They have been ignored, or old ones used instead.
123285
What happens if there is a security problem in a package in the universe repository four years after the 12.04 LTS release; will the package be updated from upstream, patched, or left alone?  It's my understanding that the "5 years of support &amp; security updates" applies only to the core of Ubuntu -- anything in Main repository.  Not for things in the Universe repository.    For a more specific example -- if I install Ruby now, and want to use it for the next several years on 12.04 and it has a security vulnerability; while this might be patched in the upstream (so I could always download the latest from their website and compile it myself or use a PPA), will this upstream fix be migrated into the precise package repositories? What about backports?
10540
When I log into my web server via SSH I see the information:  88 packages can be updated. 80 updates are security updates   I tried apt-get update then apt-get upgrade but each time I log in I still see the message about updates. How do I install them?
2858
Does apt-get use https or any kind of encryption? Is there a way to configure it to use it?
75758
Say you're running a server and you don't want to upgrade to Testing (Squeeze) from Stable (Lenny) to just install a required package or two.  What's the best way of installing only certain packages from Testing?
115008
I have tried put in apt config Acquire::http::proxy, and in Network>Network proxy with and without user:password@server:port and using environment variables http_proxy and https_proxy. Nothing seems to work, not even a single proxy authentication popup window.  The only proxy configuration working is within Firefox Edit> Preferences> Advanced> Network> Connection> Settings> Manual Proxy Configuration.   Using gconf to manually set the proxy doesn't work   Using Synaptic in previous Ubuntu versions was too simple.
75953
I have 20 to 3o computers on my network and I have a copy of the debian packages on /var/cache/apt/archives but when I take this downloaded copy to any other machine I need to hit an "apt-get update" , How do I avoid this ? Where is the list of packages which is updated by that command stored. I need to copy them as well, and use it on a computer which is completely offline.
110035
I normally download all .deb packages and just copy the packages from /var/cache/apt/archives directory to the rest of the computers, saving me to have to download all the updates and programs again. But since Ubuntu 11.04, the directory keeps deleting the oldest file or some kind of delete method that literally resets the amount of packages there. So then I need to download them again on the rest of the PCs. The files stay there for a couple of days, but then "magically" it's not there anymore after some days.   So what do I need to do to tell Ubuntu NOT to eliminate any files from /var/cache/apt/archives, not even the previous versions of the same package? I do not want it to delete anything from there.  Just to add, I install packages using aptitude or synaptic.
13589
I'm unsure what the current procedure for package security for Ubuntu is.  When something ends up in the Ubuntu package repositories, are the package audited by a central, trusted team and if so what level of auditing takes place?  I'm interested on whether packages are checked for:   Regular matching against known vulnerabilities/CVEs (as in, package maintainers are notified in realtime of CVE releases, and packages with unpatched (by vendors) CVEs removed). Obvious malicious code (eg reverse shells, random shell code, trojans) Poor code quality (eg unintended command injection vulnerabilities) Full security audit of all code for vulnerabilities
100364
I usually prefer to fix a Linux system than to reinstall from scratch. My computers have seen many distribution upgrades and a list of PPAs or third-party repositories. APT usually makes sure that everything works in the end. However, the fact that the package manager thinks that all required packages are 'installed' does not guarantee that all the files are present on the file system.  Such a such situation may occur if you have to work-around dependency problems with dpkg --force-*. One could also reproduce such a situation by deleting a file from /usr as root.  Is there a simple way to verify whether all files belonging to an installed package are present?  If a such a problem package is found, aptitude reinstall fixes the problem.
98475
I'm migrating a Debian server to Ubuntu 16.04. One of the packages on the Debian server is scponly which acts as a shell and permits ssh connections for scp purposes only (not login or running anything other than the scp binary). Details can be found . This package has been on the Debian through at least 2 physical server upgrades already, countless OS upgrades, and probably dates from about 2007.  scponly is not in any 16.04 repository, and isn't compiled on launchpad. Whilst I am quite capable of installing it from source, this got me wondering whether in the last 10+ years there is a better way of configuring ssh to permit scp commands only, that is more Ubuntu 16.04 friendly, and less based in the dim and distant past. Any ideas?
124145
I don't like installing apps outside my distro's official repositories. Linux's security relies a lot on having a repository meticulously curated and tested for library compatibility with current distro version, stability and security. Once I installed, from outside repos, a fancy terminal emulator that mimicked retro green/amber phosphor monitors. This app wreaked havoc in my system and I had to reinstall Ubuntu. I hesitate a lot about using PPAs as well. I only trust very few external sources, PPAs or packages downloaded from websites. But now Snap and  seems to be all the rage in Ubuntu-specialized sites.  Is it safe to install Snap apps or Flatpak apps? Are there official repos for such? How is stability taken cared of with this non-apt stuff?
120532
Imagine that, I have a fresh Ubuntu 18.04 installed. But there are some default packages or services that connects to the Internet without my consent. How to get rid of them completely or make them offline in an effective way?  As far as I now, they are:  popularity-contest - The Ubuntu Popularity Contest (or popcon, in short) gathers statistics determining which packages are the most popular with Ubuntu users.  unattended-upgrades - Automatically upgrades computer with the latest security updates.   apt-daily - Updates apt index every day automatically.   snapd - Updates snap packages automatically.  update-manager - Checks for release updates.  I could be missing something. Please post if you know...  The purpose: I want to have full control over the Internet, as in my case, Internet is limited. So, I wish to update or upgrade manually rather than automatically.
17070
I have 12.10 ubuntu and when I try to remove / install programs I get notification :      Software can't be installed or removed because the authentication service is not available.    (org.freedesktop.PolicyKit.Error.Failed: ('system-bus-name', {'name':  ':1.104'}): org.debian.apt.install-or-remove-packages   When I log in as root user (instead of user account that I regulary use) i have no problems.
118106
Are all Ubuntu download servers an exact copy of the main server? Can a software be on a server but not be on another server? Can the version of a software be different on different servers? Where is the main server?