Questions regarding password-based authentication and password management

learn more… | top users | synonyms

8
votes
3answers
17k views

How to take 'password' like input in shell script? [duplicate]

Possible Duplicate: How to hide commands typed in a Linux shell? Reading passwords without showing on screen in Bash Scripts I would like to take a password as input, but I want user to ...
8
votes
2answers
14k views

How to expire a password? (For inital account creation)

I've often created temporary passwords for users for my own development machine for initial id creation. For other environments, I've seen admins have the ability to have a password show as expired ...
8
votes
3answers
319 views

Clear / erase a mistyped password in a terminal

One thing that annoys me using Linux's terminal is when I have to type a invisble password, like when you run ssh the terminal I was wondering if there's a way to clear/erase the invisible password ...
8
votes
2answers
347 views

What is most secure and simplest way to have a user-typed password on bash become part of stdin to a program?

I'm looking for the (1) most secure and (2) simplest way to have a user type a password on a bash shell prompt and to have that password become part of stdin to a program. This is what the stdin ...
8
votes
1answer
3k views

GNOME-keyring KWallet integration?

I use some GNOME apps, and some KDE apps, so some of them use G-keyring and some KWallet... What I would like to have is a single place for managing passwords. Is there a way to integrate G-keyring ...
7
votes
5answers
18k views

Can I change root password by sudo, without su?

I can sudo, but I don't have the root password so I can't su root. Using sudo, can I change the root password?
7
votes
7answers
2k views

Is there a way to store Firefox passwords in a local encrypted database in Linux?

I want Firefox to "remember" my passwords so I don't have to type them in; unfortunately, the built-in password manager stores them in plain text, which is too high a security risk. I'd like to find a ...
7
votes
3answers
693 views

Is w command safe for users?

Some applications allow to pass password as an argument. For example: mysql --user=user_name --password=your_password db_name Is it safe? Besides the fact that typed password would be saved in bash ...
7
votes
2answers
8k views

/etc/shadow : how to generate $6$ 's encrypted password?

In /etc/shadow file there are encrypted password. Encrypted password is no longer crypt(3) or md5 "type 1" format. (according to this previous answer) Now I have a ...
7
votes
1answer
1k views

SSH keeps skipping my pubkey and asking for a password

Everytime I ssh onto my remote server I need to provide the password. I copied my public key (id_dsa.pub) to the remote server using: ssh-copy-id -i id_dsa.pub user@server I checked it was ...
7
votes
3answers
884 views

Root and my password are the same

If I cat /etc/shadow I can get the encrypted passwords of root and my user. These passwords are the same (I know, bad security) for each account, but in /etc/shadow they show up as being different ...
7
votes
2answers
7k views

Why is sudo telling me my password is wrong?

I recently installed OpenBSD 4.9 in my computer, so I could learn a little bit about Unix-like operating systems. I added a new user to the system called bruno. Ok. When I use the 'sudo' command, it ...
7
votes
2answers
5k views

I try to add passwords to the “pass” password manager. But my attempts fail with “no public key” GPG errors. Why?

I am trying to install Pass: the standard Unix password manager, however, when I try to add passwords to the appliation I get these errors gpg: Kelly's Passwords: skipped: No public key gpg: [stdin]: ...
7
votes
3answers
3k 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
2answers
5k views

Why SSH is asking for my private key password each time

Since yesterday, each time I try to connect to an ssh server, I got asked for my password. What should I do to make SSH not ask for my password each time.
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 ...
6
votes
5answers
3k views

Passing root password safely in a shell script

I always boot up my GNU/Linux laptop in console mode. But sometimes I need to bring up the GUI mode. it always requires entering the root password. So I wrote the following script "gogui.sh" and put ...
6
votes
7answers
3k views

Encrypt a password the same way mysql does

I've created a user ... but forgotten the password mysql> create user 'blayo'@'%' identified by 'right'; Which Linux command line tool can encrypt the password the same way mysql 5.5 does ? ...
6
votes
3answers
5k views

How to unlock account for public key ssh authorization, but not for password authorization?

The ssh won't let me login, because account is locked. I want to unlock the user on my server for public key authorization over ssh, but do not enable password-ed login. I've tried: # passwd -u ...
6
votes
4answers
3k 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
3answers
8k 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 ...
6
votes
3answers
23k views

Lost password for a user on a Linux Server: How reset it?

On a Server an user 16040 has lost his password. I have password for root but don't have password for user 16040. How can I reset his password? With passwd 16040, unix ask me current password that I ...
6
votes
1answer
438 views

How can I prevent someone from gaining root access through the bootloader?

On Ubuntu 10.10 I can login as root without the root password by replacing ro quiet splash with rw init=/bin/bash. How can I secure my machine and disable this backdoor?
6
votes
1answer
4k views

How to reset password on an encrypted fs?

I've got a laptop which I haven't used since the last summer vacation: I did put Debian 7 on it and used Debian's feature to fully encrypt the disk, besides a tiny bootloader (or a tiny partition) I ...
6
votes
4answers
4k 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 ...
6
votes
1answer
636 views

No password to run command as root for fixed command? [duplicate]

Is it possible to define a rule in sudoers to allow one user to run one well defined command as root, without password or other authentication except being the right user? Are there alternatives to ...
6
votes
2answers
2k views

Pipe Password to Application When Asked

The following should be done in a bash script: curl --digest --user schmijos https://bitbucket.org/u/p/get/tip.zip -o tip.zip How can I automatically submit a password to curl when it asks for it? ...
6
votes
2answers
9k views

export HTTP_PROXY and special characters in passwd

Suppose for the sake of argument my password below is abc123@ I need to authenticate my linux machine through a corporate proxy to get patches and updates... normally I'd use this: export ...
6
votes
2answers
851 views

Is it possible (and a good idea) to do `pw lock root` on FreeBSD?

I have set up sudo on my FreeBSD server. As I now never want to log in as root anymore, I was wondering whether I should do sudo pw lock root. My questions are: Is this possible, without forever ...
6
votes
1answer
661 views

sudo testing for credentials

I have a working bash script, that may run from 0 to 8-9 minutes. It requires sudo if it finds a problem and needs to change permissions/ownership on a file. I do not want to wait for the sudo prompt, ...
6
votes
3answers
471 views

Passwords for newly created users?

I am fairly new to Linux and I have question regarding users. When I use the useradd command I don't specify a password. I must use the passwd command afterwards. Does this mean that the user is ...
6
votes
1answer
559 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, ...
6
votes
1answer
153 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?
6
votes
1answer
6k views

How to reset KDE wallet password in linux?

I have installed OpenSUSE on my laptop. I am trying to connect to my wifi. I entered my wifi password (correctly) and then it is asking for my KDE wallet password. I set the KDE password but forgot ...
6
votes
2answers
2k views

How to see password as we type it

In debian wheezy terminal i type su - It ask for password, which i type but it dont show anything as Password: I want to it to show at least some asterisks as the placeholder for the password ...
6
votes
2answers
6k views

Another account with same uid as root gets prompted to set new password for root, not itself

After upgrading the os from 5300-06 to 5300-11, this weird behaviour happened. My system had another unix account, let's call it "abc", purposely configured its uid to 0 for working as a root with ...
6
votes
3answers
82 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 ...
6
votes
4answers
720 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 ...
6
votes
1answer
1k views

Save password in bash script for multiple queries

I would like to know if there is a safe way to only be queried for a password once in a custom bash script, and then save it somehow to be used for later needs. At the end of the script it should be ...
6
votes
3answers
3k views

Logged on via ssh-key, can I reset my account password?

I am logged in on a server via sshkey (ssh -i /home/me/.ssh/ssh-key me@server). I got sudo rights on that server from the admin, but I can't exercise them, since I forgot my actual Unix password (or ...
6
votes
2answers
228 views

Linux graphical password dialog trick security

When we run a command by sudo, the password is asked [sudo] password for user If the sudo is not typed the password should not be asked. If asked, I would assume it as a fraud by the application. ...
6
votes
1answer
381 views

Any random password results in successful login on tty

I can login to my machine (FreeBSD 9.1-RELEASE) for any user (for example: root or operator or any that exists in /etc/passwd) with any random password that I type... I tried to reset password for ...
6
votes
1answer
263 views

epiphany plugin for password storage

I am looking for a keepass plugin for epiphany. Something like PassIFox for Firefox: PassIFox "behaves" like a new password storage for firefox - and redirects all queries (fetch/store etc..) to ...
5
votes
3answers
2k views

Stracing su and ssh shows the password. Is this a security flaw or am I missing something?

I'm currently fascinated by strace so, being new to it, I decided to play around a little. As suggested by the question title, I tried both strace su and strace ssh. Both commands displayed the ...
5
votes
3answers
5k views

chroot permission denied! But Im root!

I am trying to chroot into an old HD to change a forgotten password, but chroot says permission denied? what gives? I am root! The harddrive I am trying to chroot into is an old version of edUbuntu ...
5
votes
3answers
697 views

Does the shadow file have encrypted passwords?

man 5 shadow says this about the 2nd field: encrypted password Is that true nowadays? I think it should say "hashed password". Am I correct?
5
votes
4answers
634 views

How do I put comments in my /etc/shadow file?

I am running through some system upgrades and my package manager is showing changes between the upstream /etc/shadow and mine. I would like to put some comments in the file for next time this ...
5
votes
2answers
256 views

How is the su command masking/protecting my password from being displayed on screen? [duplicate]

Apologies if this is an abstract question - I'll try to be as specific as possible. When I'm at the bash shell and switch to a different account via su - foo, I'm prompted for a password. The ...
5
votes
2answers
11k views

Two ways to lock a password but only one to unlock

CentOS 6 Linux has two ways to lock a password: passwd -l usermod -L Today I found out, that they do something different. passwd writes two exclamation marks into the shadow file. # passwd -d ...
5
votes
3answers
2k views

Remote shell script Enter passphrase for

How can I run a script to log into a remote server and execute a remote ssh command without entering in my passphrase? For example: When I log onto a remote server and execute the git pull command I ...