[GLLUG] Question about software updater problem

Christopher Hunter cehunter at gb-x.org
Mon Apr 25 18:47:32 UTC 2016


Hi Jackie

I use Ubuntu pretty much exclusively, so if you have questions, I've 
probably got the answers.  Feel free to drop me a line directly if you like.

Ubuntu is slightly different to some other Linux Distributions in the 
way that it handles passwords.  I'll explain:

As you're probably aware, Linux is based on Unix (at least in the way 
that it works and the commands it accepts).  Unix was a 1970s operating 
system developed at Bell Laboratories (the phone company) in the 
'States.  It was originally written to do billing, but quickly grew to 
control the telephone exchanges themselves.  It left its 
telecommunications roots quite quickly, and ended up at IBM as the 
default "mini-computer" operating system of choice.

In the late 80s, Linus Torvalds wanted to be able to run Unix on a home 
PC.  There was a commercial option - "Minix" - but it was very 
expensive.  That's why Linus set about writing his own "Little Unix"....

Linux retains its Unix roots, and part of those is the way that Linux 
handles Users and Passwords.  In the Linux world, there are basically 
two kinds of Users - the ordinary "Jackie" or "Chris" who want to do 
day-to-day computing and "Administrators"  who have the right to alter 
anything on the system.  This gives rise to the Linux security that 
we're all so proud of, and entirely prevents Linux being affected by the 
craziness of viruses and other malicious software.

So - on a Linux system, you have Users and an Administrator.  He's 
called "Root" or the "Super-User" in Linux-speak, and has his own, very 
secure, password.  The Users - Chris, Jackie, Bob and Jenny - each have 
their own user names and individual passwords.  Bob can store his own 
work on the computer, and it's secure (unless he chooses to share it).  
The other users will be able to see that Bob has created a file and may 
be able to see its name, but they can't look inside it!

Root has the right to look at anything, and can change the permissions 
of Users.  If (for example) Root decides that Jenny's not allowed to 
print or connect to the Internet, he can change her permissions so that 
if she tries, she'll get an error message (telling her that printing or 
external connections are denied).....

That's just a trivial example of the way in which a Linux system can be 
administered, and is standard across most Linux Distributions - in fact 
this idea of Permissions is fundamental to the security of a Linux system.

Ubuntu is - slightly - different.  It's aimed at making it much easier 
to use, and reduces security (a bit) to allow that to happen.  Instead 
of having a "Root" user, it grants some of the Users the right to 
administer the system.  The higher level of access is gained by using an 
additional text command called "sudo". This command is used at the 
beginning of an instruction to tell the system to treat the following 
command as if it came from "Root". Incidentally, "su" and "sudo" are 
named for the Super User.

Important administrative stuff - like adding or updating software - is 
always done by the Super User (Root).  On Ubuntu, you should log in in 
the normal way - entering your username and password - then, when you 
want to issue a system-altering command, you preface your command with 
"sudo".  When you hit Enter, the system will ask you for your password - 
the one you normally log-in with - then will do the command when you've 
replied.

This isn't quite as secure as the traditional Unix / Linux way, but it 
does confirm that it's not some viral nasty trying to install itself!

Users and passwords are fundamental to Linux, and it's good to have an 
understanding of who can do what...!  The people on a system who are 
allowed to use the "sudo" command are called "sudoers" - and Users can 
be prevented from having this right, by removing their Username from the 
list of "sudoers".

You can see that this is a huge topic, and I hope that I've explained it 
reasonably well.  If you have questions - drop me a line.  The range of 
commands available in Linux is astonishingly big, but there are really 
good on-line manuals.  Visit www.linux.org for pointers to just some of 
the on-line resources freely available to you

Good luck with your endeavours

Chris























On 25/04/16 17:32, jackie menon wrote:
> Hi Steve
> Thanks for your advice. I can get as far as typing in the new password 
> but when I type no charachters are coming up on the screen and I get 
> the message "sorry, try again".
> Jackie
>
> On Monday, 25 April 2016, Steve Parker <steve at steve-parker.org 
> <mailto:steve at steve-parker.org>> wrote:
>
>     Hi Jackie,
>
>     When you first installed the PC, it should have asked you to
>     choose a username and password (along with a name for the PC
>     itself, and a few other questions). It is that password which you
>     need to enter.
>
>     If you are not sure of the password, you reset it quite easily:
>
>     1) open a terminal (just type "Terminal" in the dash bar).
>
>     2) Then run this command in the terminal window, followed by
>     pressing the RETURN key:
>       sudo passwd $USER
>
>     You should be prompted to enter a new password for your user. You
>     can choose a new password, and this will now be the password to
>     use for the system updates, too.
>
>     Steve
>
>     -----Original Message-----
>     From: "jackie menon" <jacqueline.menon at gmail.com
>     <javascript:_e(%7B%7D,'cvml','jacqueline.menon at gmail.com');>>
>     Sent: Monday, April 25, 2016 2:32pm
>     To: "GLLUG at mailman.lug.org.uk
>     <javascript:_e(%7B%7D,'cvml','GLLUG at mailman.lug.org.uk');>"
>     <GLLUG at mailman.lug.org.uk
>     <javascript:_e(%7B%7D,'cvml','GLLUG at mailman.lug.org.uk');>>
>     Subject: [GLLUG] Question about software updater problem
>
>     Hi there
>
>     I am still a novice with regards to Ubuntu.
>     I am trying to do my software update. I get the message that
>     software is available to update and am asked if I want to install
>     it. I click install now and get a box which says "to install or
>     remove software, you need to authenticate" and asks for a password.
>     I am not sure which password is required. I have also read on some
>     forum pages that this is a bug and I should just press the escape
>     key. This does not work.
>     I would welcome any suggestions of how to proceed.
>     Regards
>     Jackie
>
>
>
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