2
votes
1answer
12 views

Understanding passwd --keep-tokens

On GNU/Linux, I do have trouble understanding the meaning of the --keep-tokens option for passwd. As it doesn't seem to be much used as I am not able to find any examples and only online copies of man ...
0
votes
1answer
63 views

How does Linux verify the login password?

I would like to know how the password verification in Linux works. I know that the passwords are stored as a hash in /etc/shadow file and user information is in /etc/passwd file. My understanding ...
1
vote
1answer
48 views

How to check my account on embedded linux without “/etc/passwd”?

On some embedded linux systems, there is no /etc/passwd file and /etc directory is not writable (which means I cannot set user account and password?). Then what is my (default) account name and ...
-1
votes
1answer
42 views

Password length and complexity

I am using CentOS and I want to set the minimum password length, minimum password expiry , maximum password expiry and password complexity in my system. I have looked over some tutorials to change ...
3
votes
3answers
240 views

Changing user password through GUI app

I was making a GUI application to manage users and groups in Linux! I'm done with the part where it creates a new user, but stuck with the part where it gives the newly created user a new password. ...
5
votes
3answers
48 views

different passwords depending on plugged-in devices

I would like to have different passwords for my account(s): When (e.g.) a certain USB stick is plugged in then an easy password is to be used. The idea is: If I leave my computer then I take the stick ...
1
vote
2answers
65 views

Why does it take more time for a login to fail than to succeed? [duplicate]

When logging in to my PC, and the password is correct, the login takes place nearly instantaneously. When the password is wrong, it takes a few seconds of waiting until the hint "The password is not ...
7
votes
4answers
936 views

Will there be always a pair of same UID and GID?

I have to change file/directory's ownership using chmod .I know only owners's username but want to change default group name simultaneosly . At this stage group name is not decided so I am putting ...
2
votes
1answer
67 views

Root Password Policy and Refresh

Unfortunately the infrastructure I work in has static root passwords that are very rarely refreshed. So people leaving the company will have our root passwords and it can potentially be leaked to ...
4
votes
4answers
193 views

Login into a GNU/Linux distribution is taking too long

So, When I try to login with my username and password (in tty), and insert a wrong password, I need to wait around 5 seconds for the system to tell me that the password is wrong. Why the validating ...
1
vote
1answer
177 views

Resetting password expiry date by number of days instead of specifying date

Is there a way with either commands passwd or chage to force the password to expire 90 days from the time of command execution? I know I can do it by date, such as: chage -E "2014-07-31" userid ...
1
vote
0answers
383 views

PAM's passwd retry prompt fail

I am trying to use PAM to stop password reuse. Adding 'remember=24' to pam_unix stores the old passwords hashed with MD5 which I find unnerving. I was recommended 'pam_pwhistory' instead. Here is the ...
0
votes
2answers
104 views

Make file in linux readonly

Is there a way to make a file readonly permanently in linux. Or can I put a password to a file to make it readonly, then apply that password again to change its permission, or before they can alter ...
1
vote
1answer
253 views

How could I eliminate Kerberos for passwd?

When I issue a command to change my password like this: sudo passwd huahsin The system prompt me: Current Kerberos password: I don't know what I have done to the system configuration, how could I ...
0
votes
1answer
124 views

Change sudo and root password on Debian

I have sudo access, but I don't remember the sudo or root password; how do I change it from my limited account using sudo?
5
votes
3answers
835 views

Why is the 'sudo' password different than the 'su root' password

On my personal machine, I often type sudo in front of certain commands in order to accomplish administrative tasks. I had hoped to avoid doing this throughout the day, by typing su root and providing ...
1
vote
1answer
416 views

Reverse id command, I want the User/Group Name from the uid or gid

I know some uid and gids that I dont know who they belong to and they are not in /etc/passwd (could be LDAP or from another system). How do I get Id info from only uid or gid preferably without using ...
1
vote
2answers
726 views

Edit home directory for an LDAP user in Linux

I have an LDAP user who accesses a server based on having the appropriate LDAP host attribute via sssd. This user does not show up in /etc/passwd because he is not local. How do I modify his home ...
1
vote
3answers
459 views

How to gain root privileges for specific user if we have root password? [closed]

Can someone suggest how can I change process privileges in Linux to root ? Assume, I have a normal process running under some user-consider me. Now my script should create some users using 'useradd' ...
3
votes
1answer
1k views

Resetting password in Linux Mint when disk is encrypted

I have a system (VM, actually) with Linux Mint 15 on it. The disk is encrypted, but I remember that password -- just not the password for my account. I've tried changing the command in GRUB from ro ...
5
votes
4answers
172 views

How to log into database via script securely?

I am wondering about whether it is acceptable (security-wise) to have database login credentials (user/pass) set in an environment variable or passed in as a command-line parameter? Both of these ...
7
votes
1answer
8k views

Manually generate password for /etc/shadow [duplicate]

I need to manually edit /etc/shadow to change the root password inside of a virtual machine image. Is there a command-line tool that takes a password and generates an /etc/shadow compatiable password ...
2
votes
1answer
221 views

How to change the forgotten root password?

I am very new to Debian linux, I forgot my root password...actually I think I know what it is because it is the same password I have for pretty much everything but in the Terminal in tell me "Sorry, ...
2
votes
2answers
199 views

Equivalent of “passwd -sa” in RHEL?

I feel a little silly having to ask this, but: In Solaris you can issue a passwd -sa command which gives you (more or less) the same output as passwd -S userName does, except it prints out the status ...
1
vote
1answer
351 views

How to safely put user typed password into a file?

Is there any way to put the password typed by user into a file (either in Unix or in expect). read -s -p "enter password" input echo $input > file Is the above code safe? I want to use that ...
3
votes
2answers
3k views

Ubuntu password policy

I want to set the system-wide password policy on an Ubuntu 12.04 LTS server. Googling around, a lot of people point to this (very old) document: ...
1
vote
1answer
134 views

How do I keep KDE from asking new users for a password when I use /etc/skel to set up their enviroment?

I made this nice custom KDE setup on Arch Linux with customised settings like desktop background, panel settings, kwin settings, etc. I heard that if you copy all the hidden files from your ...
5
votes
2answers
11k views

How do I set the password of a new user after the account has already been created?

I used the 'useradd' command to create a new account, but I did so without specifying the password. Now, when the user tries to log in, it asks him for a password. If I didn't set it up initially, ...
6
votes
4answers
1k views

Is it possible to change password database file(/etc/passwd) in linux?

Is it possible to change password database file(/etc/passwd) to some other file. How does this authentication mechanism work internally ? Does it depend on pam ?
6
votes
1answer
150 views

Why do we need an expiration period?

Why is there a gap between the expiration of an account and its complete deactivation, when one can no longer log in or change his password when it became expired?
7
votes
3answers
5k views

Getting the password expire time

Let me preface this with: I do NOT have root access available. I recently got locked out of my account because I did not know the password expiration was getting close, then elapsed. I want to add a ...
2
votes
1answer
2k views

How to set a new password from bash?

I'm using busybox with a limited passwd (I don't have --stdin option) and without chpasswd and I need to change the password of an user from bash. Here is my best result: echo newpassword > ...
3
votes
2answers
2k views

Second field in /etc/shadow

If the second field of the /etc/shadow file is set to !!, does it mean that the account is disabled? Or does it mean that the account is active with no password assigned?
10
votes
4answers
18k views

How to check password with Linux?

I want to check, from the linux command line, if a given cleartext password is the same of a crypted password on a /etc/shadow (I need this to authenticate web users. I'm running an embedded linux.) ...
2
votes
4answers
610 views

sudo without password - security? [duplicate]

Possible Duplicate: What specific vulnerabilities am I creating by disabling the sudo password? I'm involved yet again in the old argument on whether sudo without password is secure enough ...
10
votes
3answers
1k views

How do I log into my Linux laptop if I have forgotten both the login and password?

How do I log into my Linux laptop if I have forgotten both the username and password?
2
votes
1answer
724 views

root password changed automatically

I have my system on dual boot (win7 and RHEL 6). I have 2 user account on RHEL 6. A normal user and a root user. I put passwords of both accounts same. It was working fine from 5 6 days. Yesterday I ...
7
votes
3answers
2k views

Why does my sudo ask for password only once but evaluate thrice?

$ sudo some_command Password: Sorry, try again. Sorry, try again. Sorry, try again. sudo: 3 incorrect password attempts $ This is what my shell prints when I enter a wrong password to a sudoed ...
7
votes
5answers
17k views

Program for decrypt linux shadow file

Is there any program or script available for decrypt Linux shadow file ?
1
vote
1answer
1k views

How to reset Linux root and grub passwords?

If we forget our Linux root password, we can change it by changing grub's boot options. But in this case, we also set a grub password and forgot both passwords. How can we recover both?
4
votes
3answers
239 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: ...