5
votes
1answer
75 views

Require private key for sudo

For added security, I would like to require a private key to use sudo on my Ubuntu Server box. I've added private key authentication for sudo as described at ...
1
vote
0answers
55 views

Ulimits and pam modules

Can you explain me the relation of ulimit setting on a proccess and line session required pam_limits.so in pam module. In wich modules i really require this line? I have this line in pam.d/su ...
2
votes
1answer
505 views

Securest way to authenticate users against /etc/shadow using PHP?

This question became important to me, since I'm setting up a Horde environment and want to use the system accounts. Doing some search I found mainly 4 ways of doing that, which all seem to have some ...
2
votes
2answers
3k views

Avoid “Authentication token manipulation error” on password change

I'm implementing a security policy that will force the users to introduce stricter passwords when they change their own: The /etc/pam.d/passwd configuration file is: #%PAM-1.0 auth include ...
0
votes
1answer
46 views

Let pam module use hostname -s

Our hostname command gives back the servername.domain. This is in conflict with our authentication mechanism with our Active Directory. Is it possible to let the pam module use hostname -s (the ...
4
votes
3answers
1k views

Restrict ssh login from LDAP to users who have a /home directory

I have an Apache server (RHEL 6) hosting multiple user web pages which currently is connected to my Active Directory environment to authenticate users. The server is used to automatically host content ...
6
votes
2answers
11k views

Effect of entries in /etc/securetty

By default on RHEL 5.5 I have [deuberger@saleen trunk]$ sudo cat /etc/securetty console vc/1 vc/2 vc/3 vc/4 vc/5 vc/6 vc/7 vc/8 vc/9 vc/10 vc/11 tty1 tty2 tty3 tty4 tty5 tty6 tty7 tty8 tty9 tty10 ...
2
votes
4answers
12k views

vsftpd fails pam authentication

Moving a tried-and-true vsftpd configuration onto a new server with Fedora 16, I ran into a problem. All seems to go as it should, but user authentication fails. I cannot find any entry in any log ...
6
votes
4answers
2k views

SSH authentication: either SSH keys or one time password

I have an Ubuntu 10.04 Linux server that I normally ssh into (from my home machine) using ssh key authentication. However, sometimes I need to ssh remotely from potentially insecure machines (like ...
4
votes
1answer
248 views

Confused about PAM configuration stanza and the roles of the control-flag parameters

I just begun studying for the RHCE. While on the topic of PAM configuration, I was a little perplexed with this stanza from /etc/pam.d/system-auth: auth required pam_env.so auth ...
5
votes
1answer
551 views

Custom PAM modules and security considerations

I am writing my own PAM module that will be part of an application that I am developing, but I'm not sure exactly where to put it. My module basically does network-level authentication (with other ...
4
votes
2answers
4k views

Can I create a local only guest account?

Is it possible to create a "guest" account in Linux? by "guest" account I mean an account that does not require a password to log in graphically. I want this account for when people come over and are ...
5
votes
1answer
3k views

What happens when your password expires and you're using key authentication?

on one of the boxes I don't control at work I use ssh keys to log in. Our passwords are set to expire after a few months. What happens if I don't reset my password and it expires? will I still be able ...
43
votes
2answers
11k views

Why is there a big delay after entering a wrong password?

I notice a weird (well, according to me) thing about passwords. For example, if I type an incorrect password during login, there will be a few seconds' delay before the system tells me so. When I try ...
7
votes
4answers
1k views

How to set up two-factor authentication with OTP on FreeBSD?

I have a FreeBSD hosted server that I like to be able to get to from anywhere. Normally I use SSH publickey to log in, or if I don't have my SSH private key available then I might use regular password ...