Content related to computer security., i.e. content about policies, mechanisms, etc. needed make sure data is not leaked or corrupted and services available in all circumstances.

learn more… | top users | synonyms

3
votes
1answer
210 views

Is there a standard way to configure what policy iptables loads on startup under Debian?

I've just started playing with Debian 6.0 (Squeeze) in a VPS environment, as a way to learn more about system administration. One thing I'd like to configure is a default packet filtering policy. ...
6
votes
2answers
4k views

Write to a file without redirection?

I am writing a regular compiled application that needs to create a special file and write a magic cookie into it. I can’t write the file directly from the application, the system security model ...
4
votes
1answer
132 views

How can I run keychain in a way that only has the first shell prompt for keys on startup?

I open multiple shell tabs when I start KDE, and I've just added keychain to my ~/.shellrc the problem is that all the tabs prompt for key passwords when I login. This is quite annoying to do this. Is ...
1
vote
2answers
131 views

How would you create a user with the HOME_DIR field in /etc/passwd completely blank?

Closest I can come is: useradd --home / -r --shell /sbin/nologin someuser But this creates an entry into /etc/htpasswd that looks something like this: someuser:x:100:100::/:/sbin/nologin I want ...
6
votes
2answers
884 views

I/O-overhead of dm-encrypted device?

What would be the Read-/Write-overhead when using dm-crypt (LUKS) as full disk-encryption (including root partition) on a Linux-Desktop (Ubuntu)? I plan to stack it like so: LUKS > LVM > ext4 The CPU ...
1
vote
5answers
408 views

Does verifying packages enhance security and/or stability of a system?

RedHat/CentOS and Ubuntu both provide packages to verify the contents of a package. CentOS uses rpm -V. Ubuntu uses debsums. I've spoken to admins who run these tools to verify the packages on their ...
9
votes
2answers
1k views

What encryption does vim -x use?

I read man vim, :h -x and :h encryption none of this actually says what algorithm it's encrypted with.
2
votes
1answer
842 views

How to restore GnuPG key after reinstall?

I know that GnuPG is all about security, thus it's not giving many chance of retrieve private keys (otherwise anyone could do it) but I've got a private key, and my own rev.asc file. I had to ...
4
votes
1answer
236 views

What's the best way to configure shared filesystem directories? (beyond standard unix perms)

I have multiple users on my system. I'd like to have shared directories like music, video. pictures etc. The problems is that I want users to be able to write any new files to any directory, but not ...
5
votes
4answers
336 views

Is it possible to use pendrive as key for Linux system

I want to give high security for my linux box. So i planed to use my pen drive as key for my linux box. How can i do it ?
4
votes
3answers
266 views

Randomise or shred memory of an application

Is it possible to randomise or shred memory of a particular application just after its life ends, or better, whenever it deallocates some memory? A command-line utility like this would be perfect: ...
6
votes
2answers
269 views

Lock some accounts during some time periods

Is it possible to lock some accounts in order to be accessible only during specific time periods? For instance the account joe should only be accessible during office hours.
2
votes
1answer
492 views

How to update gnome keyring password?

Last weak I updated my password on my laptop. Then every time when I logged in, it would prompt for my old password to open the keyring for network manager. To fix this in a terminal I use rm ...
3
votes
1answer
336 views

Learning about iptables: Is this Slicehost example any good?

In preparation to eventually launch my first website, I've been playing with Ubuntu Lucid Server in a VM on my WinXP machine. I've been alternating between the Linode and Slicehost tutorials/articles ...