How do I add users using Python scripts on a Linux machine

[Ramdas]

How do I add users using Python scripts on a Linux machine?

Someone has a script?

[Daniel Klein]

Re: How do I add users using Python scripts on a Linux machine

On 1 Jan 2007 11:33:42 -0800, "Ramdas" <ramdaz@gmail.c omwrote:

>How do I add users using Python scripts on a Linux machine?
>
>Someone has a script?

This should be as easy as something like:

os.system("/usr/sbin/useradd -m -d /home/newuser -s /bin/ksh")

Dan

[Hari Sekhon]

Re: How do I add users using Python scripts on a Linux machine

That is shell scripting with a python layer on top. Is there a
specific reason you have to use python? Why not just use shell, that's
what it's designed for? Unless you have some complex maths/networking
requirement or something on top.

-h

On 01/01/07, Daniel Klein <danielkleinad@ gmail.comwrote:

On 1 Jan 2007 11:33:42 -0800, "Ramdas" <ramdaz@gmail.c omwrote:
>

How do I add users using Python scripts on a Linux machine?

Someone has a script?

>
This should be as easy as something like:
>
os.system("/usr/sbin/useradd -m -d /home/newuser -s /bin/ksh")
>
Dan
--

http://mail.python.org/mailman/listinfo/python-list

>

--
Hari Sekhon

[Ramdas]

Re: How do I add users using Python scripts on a Linux machine

Well,

I need to add users from a web interface for a web server, which runs
only Python. I need to add users, set quotas and in future even look at
managing ip tables to limit bandwidth.

I know os.system(), but this has to be done through a form entry
through a web interface.

Anyways thanks, do advise if there more pythonic solutions

Ramdas


Hari Sekhon wrote:

That is shell scripting with a python layer on top. Is there a
specific reason you have to use python? Why not just use shell, that's
what it's designed for? Unless you have some complex maths/networking
requirement or something on top.
>
-h
>
On 01/01/07, Daniel Klein <danielkleinad@ gmail.comwrote:

On 1 Jan 2007 11:33:42 -0800, "Ramdas" <ramdaz@gmail.c omwrote:

>How do I add users using Python scripts on a Linux machine?
>
>Someone has a script?

This should be as easy as something like:

os.system("/usr/sbin/useradd -m -d /home/newuser -s /bin/ksh")

Dan
--

http://mail.python.org/mailman/listinfo/python-list

>
>
--
Hari Sekhon

[Ivan Voras]

Re: How do I add users using Python scripts on a Linux machine

Ramdas wrote:

Well,
>
I need to add users from a web interface for a web server, which runs
only Python. I need to add users, set quotas and in future even look at
managing ip tables to limit bandwidth.
>
I know os.system(), but this has to be done through a form entry
through a web interface.
>
Anyways thanks, do advise if there more pythonic solutions

What you're looking for is actually a pretty complex thing. You *could*
in theory manage /etc/passwd (and its "shadow" file) - you can find
crypto primitives like MD5 and DES on the 'net, but note that you must
run your script under the 'root' account in order to write (and even
read!) the passwd database. The same goes for using os.system and the
built-in OS utility. Be aware of security implications if you're running
your web server under the root account.

[Ravi Teja]

Re: How do I add users using Python scripts on a Linux machine


Ivan Voras wrote:

Ramdas wrote:

Well,

I need to add users from a web interface for a web server, which runs
only Python. I need to add users, set quotas and in future even look at
managing ip tables to limit bandwidth.

I know os.system(), but this has to be done through a form entry
through a web interface.

Anyways thanks, do advise if there more pythonic solutions

>
What you're looking for is actually a pretty complex thing. You *could*
in theory manage /etc/passwd (and its "shadow" file) - you can find
crypto primitives like MD5 and DES on the 'net, but note that you must
run your script under the 'root' account in order to write (and even
read!) the passwd database. The same goes for using os.system and the
built-in OS utility. Be aware of security implications if you're running
your web server under the root account.

How about invoking scripts with SUID root set?

[Jan Dries]

Re: How do I add users using Python scripts on a Linux machine

Ivan Voras wrote:

Ramdas wrote:

>Well,
>>
>I need to add users from a web interface for a web server, which runs
>only Python. I need to add users, set quotas and in future even look at
>managing ip tables to limit bandwidth.
>>
>I know os.system(), but this has to be done through a form entry
>through a web interface.
>>
>Anyways thanks, do advise if there more pythonic solutions

>
What you're looking for is actually a pretty complex thing. You *could*
in theory manage /etc/passwd (and its "shadow" file) - you can find
crypto primitives like MD5 and DES on the 'net, but note that you must
run your script under the 'root' account in order to write (and even
read!) the passwd database. The same goes for using os.system and the
built-in OS utility. Be aware of security implications if you're running
your web server under the root account.

A solution that is both more pythonic and avoids the problems listed
above would be to migrate user management from /etc/passwd to an LDAP
(though pam_ldap). That's the approach I took in a similar situation.
Sure, it adds the overhead of setting up and running an LDAP, but
managing users and their quota through python_ldap is much cleaner and
more flexible than doing so using os.system(), certainly from within a
web application.
That doesn't alter the fact though that security must be properly
considered in any application that can add users.

Regards,
Jan

[Sebastian 'lunar' Wiesner]

Re: How do I add users using Python scripts on a Linux machine

Ravi Teja <webraviteja@gm ail.comtyped

>
Ivan Voras wrote:

>Ramdas wrote:

Well,
>
I need to add users from a web interface for a web server, which
runs only Python. I need to add users, set quotas and in future
even look at managing ip tables to limit bandwidth.
>
I know os.system(), but this has to be done through a form entry
through a web interface.
>
Anyways thanks, do advise if there more pythonic solutions

>>
>What you're looking for is actually a pretty complex thing. You
>*could* in theory manage /etc/passwd (and its "shadow" file) - you
>can find crypto primitives like MD5 and DES on the 'net, but note
>that you must run your script under the 'root' account in order to
>write (and even read!) the passwd database. The same goes for using
>os.system and the built-in OS utility. Be aware of security
>implications if you're running your web server under the root
>account.

>
How about invoking scripts with SUID root set?

Linux seems to ignore SUID bit on scripts:

[lunar@nargond]-[17:03:23] >~/test
--cat uidtest.py
#!/usr/bin/python
import os

print 'uid:', os.getuid()
print 'effective uid:', os.geteuid()
os.system('whoa mi')

[lunar@nargond]-[17:03:28] >~/test
--ls -l uidtest.py
-rwsr-xr-x 1 root root 112 2007-01-02 17:03 uidtest.py

[lunar@nargond]-[17:03:46] >~/test
--/home/lunar/test/uidtest.py
uid: 1000
effective uid: 1000
lunar

Anyway, you should definitely think about security issues. Not all
people out there are friendly...

--
Freedom is always the freedom of dissenters.
(Rosa Luxemburg)

[Carsten Haese]

Re: How do I add users using Python scripts on a Linux machine

On Tue, 2007-01-02 at 17:17 +0100, Sebastian 'lunar' Wiesner wrote:

Ravi Teja <webraviteja@gm ail.comtyped
>

Ivan Voras wrote:

Ramdas wrote:
Well,

I need to add users from a web interface for a web server, which
runs only Python. I need to add users, set quotas and in future
even look at managing ip tables to limit bandwidth.

I know os.system(), but this has to be done through a form entry
through a web interface.

Anyways thanks, do advise if there more pythonic solutions
>
What you're looking for is actually a pretty complex thing. You
*could* in theory manage /etc/passwd (and its "shadow" file) - you
can find crypto primitives like MD5 and DES on the 'net, but note
that you must run your script under the 'root' account in order to
write (and even read!) the passwd database. The same goes for using
os.system and the built-in OS utility. Be aware of security
implications if you're running your web server under the root
account.

How about invoking scripts with SUID root set?

>
Linux seems to ignore SUID bit on scripts:

I don't think that that has anything to do with Linux or not. The script
is not the actual executable, hence its suid bit is irrelevant. You'd
have to set the suid bit on the python executable, but that would affect
all python scripts, which is probably bad.

-Carsten

[Sebastian 'lunar' Wiesner]

Re: How do I add users using Python scripts on a Linux machine

Carsten Haese <carsten@uniqsy s.comtyped

On Tue, 2007-01-02 at 17:17 +0100, Sebastian 'lunar' Wiesner wrote:

>Ravi Teja <webraviteja@gm ail.comtyped
>>

>
Ivan Voras wrote:
>Ramdas wrote:
Well,
>
I need to add users from a web interface for a web server, which
runs only Python. I need to add users, set quotas and in future
even look at managing ip tables to limit bandwidth.
>
I know os.system(), but this has to be done through a form entry
through a web interface.
>
Anyways thanks, do advise if there more pythonic solutions
>>
>What you're looking for is actually a pretty complex thing. You
>*could* in theory manage /etc/passwd (and its "shadow" file) - you
>can find crypto primitives like MD5 and DES on the 'net, but note
>that you must run your script under the 'root' account in order to
>write (and even read!) the passwd database. The same goes for
>using os.system and the built-in OS utility. Be aware of security
>implications if you're running your web server under the root
>account.
>
How about invoking scripts with SUID root set?

>>
>Linux seems to ignore SUID bit on scripts:

>
I don't think that that has anything to do with Linux or not. The
script is not the actual executable, hence its suid bit is irrelevant.

I don't think so. From what I know, the script is passed as executable
to the kernel loader, which interprets the shebang and feeds the script
through the correct interpreter. So the kernel loader sees the script
itself as executable instead of the interpreter binary. I've heard of
other Unix systems, which handle this differently (meaning that the
SUID bit on scripts has an effect), but I may be wrong.

You'd have to set the suid bit on the python executable, but that
would affect all python scripts, which is probably bad.

It _is_ bad!

--
Freedom is always the freedom of dissenters.
(Rosa Luxemburg)

[Ravi Teja]

Re: How do I add users using Python scripts on a Linux machine

How about invoking scripts with SUID root set?

>
Linux seems to ignore SUID bit on scripts:

Yes. My bad. The work around was to use native launchers. I don't
remember the details. Perhaps with the interpreter embedded to launch
it in-process and to hard code the script paths (or at least a config
file/script pointing to them) for security.

Anyway, you should definitely think about security issues. Not all
people out there are friendly...

I agree. SUID is often risky.

Web applications such as webmin that do administrative functions
through a web interface require extra precautions for security such as
restricting access to specific IPs.

[Piet van Oostrum]

Re: How do I add users using Python scripts on a Linux machine

>>>>Sebastian 'lunar' Wiesner <basti.wiesner@ gmx.net(SW) wrote:

>SWLinux seems to ignore SUID bit on scripts:

The reason is that obeying SUID bits on scripts would be a security risk.
--
Piet van Oostrum <piet@cs.uu.n l>
URL: http://www.cs.uu.nl/~piet [PGP 8DAE142BE17999C 4]
Private email: piet@vanoostrum .org

[Tim Roberts]

Re: How do I add users using Python scripts on a Linux machine

"Ramdas" <ramdaz@gmail.c omwrote:

>
>I need to add users from a web interface for a web server, which runs
>only Python. I need to add users, set quotas and in future even look at
>managing ip tables to limit bandwidth.
>
>I know os.system(), but this has to be done through a form entry
>through a web interface.
>
>Anyways thanks, do advise if there more pythonic solutions

os.system is perfectly Pythonic, and can be executed from a CGI script. The
challenge is becoming root, which is necessary to do what you ask. You can
write a simple C program that is setuid root that calls your script for
you.
--
Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.

[Sebastian 'lunar' Wiesner]

Re: How do I add users using Python scripts on a Linux machine

Piet van Oostrum <piet@cs.uu.nlt yped

>>>>>Sebastia n 'lunar' Wiesner <basti.wiesner@ gmx.net(SW) wrote:

>

>>SWLinux seems to ignore SUID bit on scripts:

>
The reason is that obeying SUID bits on scripts would be a security
risk.

I don't see a problem with SUID on scripts. If you restrict write access
to the owner, modification is hardly possible.
However, if you allow world-wide write access to your binaries and
scripts, both can easily be modified...

--
Freedom is always the freedom of dissenters.
(Rosa Luxemburg)

[Ivan Voras]

Re: How do I add users using Python scripts on a Linux machine

Sebastian 'lunar' Wiesner wrote:

Carsten Haese <carsten@uniqsy s.comtyped

>I don't think that that has anything to do with Linux or not. The
>script is not the actual executable, hence its suid bit is irrelevant.

>
I don't think so. From what I know, the script is passed as executable
to the kernel loader, which interprets the shebang and feeds the script
through the correct interpreter. So the kernel loader sees the script
itself as executable instead of the interpreter binary. I've heard of
other Unix systems, which handle this differently (meaning that the
SUID bit on scripts has an effect), but I may be wrong.

Yes, the kernel parses #! but the suid-ness is still controlled by the
target interpreter (i.e. python executable). At least BSD systems also
behave this way.