Dir permissions to hide it from other users

vargadanis · 08-28-2007, 11:12 AM

Hi!

In school we have a server and all users have their own folder in the home dir. But I can read theirs and they can read mine. I would like to remove the read and search attribs but if I do that the httpd wont be able to read the content of the www dir in it. So is there any way to grant certain rights to a dir in general and then make exceptions such as this and this dir can be read and accessed by the nobody group?
thx

bigrigdriver · 08-28-2007, 12:56 PM

If I'm not mistaken, the execute permission on a directory allows one to enter that directory; read permission allows one to read files in that directory; write permission allows one to write to that directory.

So, remove execute permission for everyone but the student to whom the directory is assigned, and only that student has access.

It should go without saying that root still has access.

win32sux · 08-28-2007, 01:14 PM

I think I managed to achieve what you are after by making sure "other" permissions on the user's home dir are set to only execute. In other words, looking like: drwxr-x--x

Code:

win32sux@candystore:~$ sudo groupadd eraseme
win32sux@candystore:~$ sudo useradd -g eraseme -m -s /bin/bash eraseme
win32sux@candystore:~$ sudo mkdir /home/eraseme/www
win32sux@candystore:~$ sudo touch /home/eraseme/secret.txt
win32sux@candystore:~$ sudo touch /home/eraseme/www/public.txt
win32sux@candystore:~$ sudo chown -R eraseme:eraseme /home/eraseme
win32sux@candystore:~$ sudo chmod 751 /home/eraseme
win32sux@candystore:~$ sudo chmod 755 /home/eraseme/www
win32sux@candystore:~$ ls /home/eraseme
ls: /home/eraseme: Permission denied
win32sux@candystore:~$ ls /home/eraseme/www
public.txt

Notice that the commands in bold were executed as non-root.

Just my

stickman · 08-28-2007, 04:05 PM

setfacl, getfacl,...

vargadanis · 09-02-2007, 03:03 AM

Quote:

Originally Posted by win32sux

I think I managed to achieve what you are after by making sure "other" permissions on the user's home dir are set to only execute. In other words, looking like: drwxr-x--x

Code:

win32sux@candystore:~$ sudo groupadd eraseme
win32sux@candystore:~$ sudo useradd -g eraseme -m -s /bin/bash eraseme
win32sux@candystore:~$ sudo mkdir /home/eraseme/www
win32sux@candystore:~$ sudo touch /home/eraseme/secret.txt
win32sux@candystore:~$ sudo touch /home/eraseme/www/public.txt
win32sux@candystore:~$ sudo chown -R eraseme:eraseme /home/eraseme
win32sux@candystore:~$ sudo chmod 751 /home/eraseme
win32sux@candystore:~$ sudo chmod 755 /home/eraseme/www
win32sux@candystore:~$ ls /home/eraseme
ls: /home/eraseme: Permission denied
win32sux@candystore:~$ ls /home/eraseme/www
public.txt

Notice that the commands in bold were executed as non-root.

Just my

That is awesome! thanx man... it helped me a lot. Now I have not feeling tht anybody can read anything I put on the server.

win32sux · 09-02-2007, 10:08 PM

Quote:

Originally Posted by vargadanis

That is awesome! thanx man... it helped me a lot. Now I have not feeling tht anybody can read anything I put on the server.

You're very welcome. BTW, when I was doing the test I forgot that in the OP you mentioned you wanted /home/*/www to be readable by the nobody group. Even though my example works (/home/eraseme/www is readable by anyone), I should have probably tightened it up like:

Code:

sudo chmod 750 /home/eraseme/www
sudo chown eraseme:nobody /home/eraseme/www

A very minor detail, perhaps I should get checked for OCD.

vargadanis · 09-03-2007, 11:35 PM

What is OCD?

win32sux · 09-03-2007, 11:37 PM

Quote:

Originally Posted by vargadanis

What is OCD?

It's Obsessive-compulsive disorder.