Better living... through (mostly)
Harmless Hacking
Unix Edition
Jan. 25, 2000
_______________________________________________________________________
See the Happy Hacker web site at http://www.happyhacker.org
Firewall gives you problems? Try http://happyhacker.org
_______________________________________________________________________
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*** Editor's Comments
***********************************************************************
Hmm... one week late. My motherboard kinda had a fit this
past week... my
IDE controller wasn't working... and most of your emails were
on my hard
drive.... well... here's the digest, better late than never.
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*** Readers' Submissions
***********************************************************************
b2329@gateway.net asks:
I am new to the world of Linux; Unix. I do have some experience
programming
in C, C++ etc. But I have been becoming increasingly interested
in Linux. My
place of employment is getting rid of several old PCs and I have
first dibs
on a few, which I plan to install Linux to play around with.
Can you suggest
a version of Linux for beginners? Also are there any good tutorials
out
there? What are they? I am interested in learning from the ground
up, unlike
some people I know who like shortcuts and don't know a bit of
programming.
Can you also suggest an extreme version of Linux? I tend to
learn things I'm
interested in extremely fast and will no doubt be ready in a
couple of
months.
You can probably guess what my intentions are for learning
Linux since I am
addressing this to you instead of some Tech person, please keep
this in mind
when making your suggestions.
7hanks [sic] in advance for any response!
[Editor: I'm not sure what exactly you mean by an "extreme"
version of
linux. And since we're not tech people here (at least, you say
we're not), I
can only guess at what your last paragraph means. As far as Linux
distro's... I put out a collection of some of the responses to
the question:
"what's your favorite *nix and why?". CNet had a nice
summary a while
back... check them... and if you really are interested in learning
from the
ground up, it won't matter what distro you have... you can get
sent to jail
from any of them :)]
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Andy Garner <siliconmonk@hotmail.com> asks:
I was wondering what books that you would suggest for a person
just starting
in Unix with a basic programing backround? I subscribe to your
newsletter
and I often find myself with basic questions regarding Unix itself.
If you
could suggest some texts I would be much appreciative.
Thanks
Andrew
[Editor: Anything by O'Reilly (the ones with the animals on
the cover). The
have books for everyone from the advanced beginner to true wizards.
If you
need something more basic... you can try the more mainstream
(read: watered
down) titles from SAM's, Que, etc... just remember two things:
fat does not
equal lots of info, and the content is inversely proportional
to the colors
on the front cover. I'd get a copy of "Essential System
Administration"
(O'Reilly), and work your way through it... that's probabaly
your best
route.]
-----------------------------------------------------------------------
Ktinga <ktinga@unm.edu> sent:
Hello,
I have a csh prompt (which will work with tcsh). I use it
everwhere and is my favorite
set shost=`basename $HOST .your.domain`
set prompt = $shost"$cwd> "
alias cd 'set old=$cwd; chdir \!*; set prompt=$shost"$cwd>
"'
Basename will strip off a string of text that you specify
from the
end of another string of text you give it. In this case, .your.domain
is
stripped off from the $HOST enviroment variable, which will include
said
smaller string of text.
The second line will set the prompt to the machine name and the
Current Working Directory (cwd) enviornment variable. I find
this helpful
for admining and keeping track of wher I am on the filesystem.
The third line is also important and ensures that the prompt
is
kept up to date. You can configure the prompt to do all kinds
of things,
like display the time and date, even read a fortune. However,
prompts can
get sort of long after a while.
I am not certain who wrote the above three lines of code. This
code appeared in a .login file that was freely passed among students
at a
up and coming research university in the southwest. I do not
know who
originally coded this. However, suffice it to say, it was not
me.
As for the gentlemen (I suppose) with the radio lan...I too
have a
small LAN inside my home and found that just using BIND v.8 worked
just
fine using standard ethernet over normal 10/100 cabeling and
hubs
(switches are too expensive for me). You may also wish to consider
that,
too. You can use a certain range of IP numbers that have been
designated
for private use only and are not used on the internet at all.
I believe
that they fall within the range of 171 to 191 or something like
that. I'm
sure it's included in an RFC somewhere.
You can retrieve the BIND software at
http://www.isc.org/products/BIND/
O'Rielly's _DNS and BIND_ by Albitz and Liu is an excellent
resource. There are also numerous FAQ's at
http://www.linux.org/
As for radio ethernet, you'll find that the speed gets to
be
annoyingly slow and that the security is pretty bad. RF signals
are
relatively easy to intercept, especially since they can be intercepted
without the transmitter or reciever realizing that the interception
is
occuring. All you need is a scanner. A common feature of radio
ethernet is
to use frequency-hopping. This technique varries the transmission
frequency rapidly; this makes it difficult for someone to listen
in. Most
vendors also offer encryption options, like DES. However, it
can slow down
the transmission speed for the process of encryption/decryption.
[Editor: Thanks for the multiple posts. The most useful unassigned
IP's are
the Class C's in the 192.168.x.x range. There's also an unassigned
class B,
and I think even a class A, but I'm not certain about that. As
far as
snooping on RF ethernet... does anyone have any knowledge of
such a task?
I'm sure a scanner should do it... or is it more complex. Do
they run trunks
(like many PD + FD's do these days)? It might be an interesting
topic to
explore... maybe on the antionline mailing list directly.]
-----------------------------------------------------------------------
And then he continuted:
Bah! This is what I get for not reading the question correctly
and
in it's entireity -I'm just a potato with arms, legs and a head.
For setting up a file server, the best way to go for Windows
is to
setup the Samba system or go NFS. You can find more information
about SAMBA (the software package)
http://www.samba.org/
Nfs resources can be had at
http://www.linuxdoc.org/LDP/nag/nag.html
http://metalab.unc.edu/LDP/HOWTO/NFS-HOWTO.html
O'Rielly's _Managing NFs and NIS_ by Stern is also an excellent
Guide. I can't think of any Samba books off hand, but they are
definately
out there.
There is a good comparison of the two at
http://www.zdnet.com/pcweek/reviews/1117/17smb.html
In case you are wondering while reading the above article,
the
difference between UDP and TCP is that TCP tries to assure that
packets
get to their destination, which takes longer while UDP does not.
They are
referred to as connectionless and connection oriented protocols,
respectively. O'Rielly is a good publisher of mostly good books.
If you are
serious about this home networking project, you can be quite
skilled and
in high demand if your designs should follow that way. Armed
with the
right literature, equipment and attitude, you should do well.
[Editor: I left your original article as well. More knowledge
is always
good.]
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zee180@lebhost.com.lb <zee180@lebhost.com.lb> says:
> pyromaniac <pyromanic@kmfms.com> sent in:
......
> what I don't really understand is what do I have to do for
the linux
> machine to act as a server, how do i connect to it from
one of the win
> machines, and what setup do i have to do in linux ?
There's a great tutorial dealing with IP masquerading here
:
http://blacksun.box.sk/tutorials.html
It's a step-by-step guide to configuring a server using Linux.
z.
[Editor: There's also the IP Masquerading minihowto. Together,
you should be
fine.]
-----------------------------------------------------------------------
Fatal Error <lazerus001@juno.com> begs:
Maybe you can help me. I'm looking for a free distro of linux
that'll run on
my PS/2 77i. It has MCA bus, 24 megs RAM, 2 gig HD, and a 486
DX/4 133mhz AMD CPU. I was hoping to breath some life into my
comp before I result in getting a new one. Can you help me out?
[Editor: Anything. www.linux.org]
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FREDIE MEZUI <mezuif@usa.net> asks:
Hi Mike,
Happy new year and many greetings for the new millennium.
I want to make you note just one thing concerning the teaching
of the
Unix/Linux file system.
they tell the Dummie how to make:
boot disk
root disk
partitioning
select what to install( Problems are begining here because as
it is a new
thing for a generical dummie, he can not know what is essential
for the
system, and after the installation where those $%&/£"£
files had been
copied)
To the poor dummie( for example ME..), they tell how to set
up Xwindows,
how to set up the root password, but they do not teach you how
the file system
is organized. i know that the Unix file system is fully customizable
so it
could change from user to user or from a corporate to another
one, but
for example what is the difference between /usr/bin and s/bin...
nobody
tells you where to find the thing.
Another example, they tell to the dummie how to set up the
DNS, so they
throw you to a file on the path /somtehing/another_thing/file.
but what about the TSR called daemons and where to find them
and what is there purpose. You could do it by following the instructions,
wich are sometimes lightly buggy but working.
When it works but you remain with a missing segment in "you
knowledge
chain"
/;).
to summarize, What i need is:
in Winodws systems , the file system is mainly on
C:\ C:\windows\system C:\windows\system32 and C:\windows...
it easy but with the unix things are quite differents.
So my question is : are there books or web site that can teach
you the
structured of the unix file system and how to navigate on it
?
Probably you have already explained it in your digest, but
i do hope you
gonna answer to me or better to al the Dummies like me. :-)))
thanks you very much.
Fredie M
Note: The english is not me native idiome so i could have made
some mistake
/:-(
[Editor: Flattery never hurts :). Seriously, as far as file
systems go, there are two main organizations... depending on
the variety of *nix, it'll vary. For the life of me, I never
remember which are which. I do remember seeing a good book on
the difference between System V and the other one (whatever it's
called :) ). Do a web search, see what you can find. As far as
bin vs. sbin... sbin is for system binaries, bin is for regular.
A couple good commands to run a "man" on... which,
find, where.]
---------------------------------------
Jacob <jratkiew@cs.iusb.edu> wrote:
I actively use tcsh. The shell prompt is configurable; look
up prompt in the
tcsh man page for the full list of options (quite long). (If
you don't have
the man pages, surf to http://linux.com.hk/man/)
For a usage example, here's my configuration:
# this is in the .tcshrc file.
set prompt="%B%m%b %~ %% "
this gives me the hostname in bold, followed by my current
working
directory, followed by a % and a space. Another prompt I use
is:
set prompt="[ %B%m%b %c2 ]# "
which is similar to the above except that it shows only the
last two terms
of the current working directory.
cheers
jacob.
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Cyanide84@aol.com <Cyanide84@aol.com>
>matt morgan <neptune2002@hotmail.com> wrote:
>
>I would like to know whether a tcsh prompt is configurable
>and how to configure it
>
>I have been told that a "set prompt=" in .cshrc
might work
>but I am having no luck finding someone that actively uses
tcsh
>
>also there are no man pages for tcsh on my computer
This is easy to do. Under my tcsh, I put my prompt settings
under ".login".
Just fire up vi, or your fav. editor and open .login, at the
end type in
"set prompt = "(minus the quotes) and put the variables
in after that. Easy as
pie, n'est pas?
-Icepik
"Just because your paranoid, doesn't mean they're not after
you!"
[Editor: "Even paranoids have enemies" (Henry Kissenger)]
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Martijn Linssen <email@withheld.com> asks
Hi Happy Hacker,
I've read all your documentation, and enjoyed it! Thank you
for sharing
your knowledge, I've learned a lot.
I encountered a UNIX (HP-UX) funnybunny when I had changed my
password
the other day (I have experience with mainframes (ICL-Open VME),
midiframes (AS/400 4.2), and lots of OS (DOS x.x, Win 95, 98,
NT, OS/2,
but this one startled me): I use the "same" password
for every system
I'm working on, since this is a matter of weeks or months, and
passwd'd
the password on UNIX, as I'm used to do.
I couldn't log on the next day, untill I tried my usual routine,
which
is CAPS LOCK "password" CAPS LOCK TAB
Apparently UNIX counts the TAB as being part of your password,
although
it doesn't show anything due to the -echo option, but anyhow:
just
change your password to "password" + TAB, and I think
that it will be
really hard to crack it ;-}
FYI: this is my first real UNIX, so it takes some time getting
acquainted to.
I'd like to be subscribed to your Happy Hacker List, but couldn't
find
it. Does it still exist?
Kind regards,
Martijn Linssen
[Editor: Nifty idea. Has anyone tried this... does it work
on different
systems? BTW, I suppose you don't want to hear the lecture on
using the same
password... the HH Digest still exists (you're reading it now
:) ) I
presume, because of the antispam instructions on your email addr,
you didn't
want it posted, correct?]
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John Kurt <enrique_1970@yahoo.com> asks
Hello,
First of all, thank you very much for all the
information you make available, this has saved me from
being bored at night.
I have a question and I have been unable to find the
answer to this:
Several weeks ago I was in a chat room spending some
time with some hackers and it seems that someone
didn't like my presence there, somehow I was "nuked".
I didn't understand how they did it, but I came back
to the same chat room, this second time one of them
displayed my IP number on screen, I made a netstat -a,
but all I could see was port 1025 and the chat server
port 8002 connecting stablished.
How could this hacker find out my IP ?, How can I
protect myself in the future ?, I was using Netscape
Comunicator 4.6.
Please, any info or advice will be greatly
appreciatted.
[Editor: Hmmm. Sure this is a unix question? I think nuking
is a topic
that's been beaten to death already... basically, it's a Denial
of Service
attack. If you're not familiar with the idea... imagine giving
someone a
nervous breakdown by calling their housing non-stop... on all
10 of their
lines... for a week... with a shrill ringing sound played when
they answer.
Oh, and they need to let legit calls get through. That's a DOS.
if you were
on IRC, your IP addr is easy to find (/whois + /who). If you
were on a java
based chat... it'd depend. Basically... there are mean people
out there. If
you're running windows <insert flame here>, and download
NukeNabber. For
Unix... you should be safe.]
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Adam asks:
KingLou says: A little linux help...
...for a confused schumck like myself. Well, let me start off
by saying
that your page has gotten me very interested in obtaining some
form of
linux. Even though have yet to retain any concrete knowledge
of this so
called "hacking" that you speak of, I am interested
nonetheless. Since I
can't really run around looking for places to purchase linux
(because I must
do everything from the privacy of the dark pit of mystery that
is my room),
I did some research into the different linux distributions that
are
available for free download on the internet. I came up with two
possibilities that seemed promising, and I wondered what kind,
if any,
knowledge you had of these particular distributions. The ones
that caught
my eye were armed linux and winlinux 2000. Both claim to be compatible
with
windows 95, which is exactly what I'm looking for because I don't
want a
whole new operating system taking over where windows used to
be, because I
don't want to be throwing up too many red flags for my snoopy
parents to
see. I was wondering if you knew anything about these programs
and if my
understanding of them is accurate (my understanding being that
I can use
windows to run these applications rather than having them take
over as my
main operating system)? Any help and/or suggestions you could
offer would
be greatly appreciated.
[Editor: I knew this for dummies/idiots/schmuck (the m is
before the u)
thing was going too far... anyway... I know nothing about either
app. Hey,
you can always convince your parents to give you money to buy
a 486... or
get a job :) ]
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Eric Korman <eok86@mail.com> wonders:
Hi, I'm a newbie at hacking, I would like to become a white
hat hacker. I
have read numerous webpages, like yours, that tell all the wannabees
to get
Linux. So, I did what it said and bought Linux, had trouble installing
it,
but installed and was able to access the internet. But I am not
able to
understand why Linux is a better operating system for hakcing
than Windows.
To me, the internet veiwing seems the same, and that I could
do all that on
Windows with IE and telnet. If you could please reply to this
e-mail, it
would be highly apreciated.
[Editor: Hmm. I don't think hacking is about viewing the internet.
That's
called "viewing the internet". I guess it depends what
you mean by
hacking... let's just say that Linux gives the low-level access
that windows
doesn't. Plus there's more code for Linux. That's basically it
in a
nutshell.]
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This is a list devoted to *legal* hacking! If anyone plans
to use any
information in this Digest or at our Web site to commit crime,
go away! We
like to put computer criminals behind bars where they belong!