I am trying to run shell comment through PHP scripts.
I want to first su into a user then run a sudo command. I tried:
echo mypassword | (su -c "sudo reboot" user2)
It doesn't work because it requires two password and I only passed one password. I checked many other posts, the solution below doesn't work for me because I don't have the sudo password for the current user. I need to change the user a first then do a sudo. Can I get some help?
echo mypassword | sudo -s ... Not work...
I know this is a bad practice. I just need it to restart server as the port 22 is closed accidentally. I can't ssh into the server to do any operations..
This is ONE time use to reboot the server from PHP side as I am not able to reach the admin to reboot the server right now. I fully understand the disadvantages... Please DO NOT suggest the disadvantages.
Since it's an one time thing, try to use the following. It spawns a sudo environment (for the current user) in which sudo reboot is called.
#! /bin/bash
read -sp "pass? " pass
expect 2>&1 <<-EOF
spawn sudo reboot
expect "*: " { send "${pass}\r" }
expect eof
catch wait result
exit [lindex \$result 3]
EOF
exit $?
You can call it as follows to automate stuff.
$ ./test.sh <<-EOF
notreallymypassword
EOF
Note: Although I think it works, I haven't tested it yet.
Related
I'm trying to write a PowerShell script to test user permissions through SSH, the idea is to connect to a distant machine through ssh, then do su to another user and test if we have the permission to do so. I managed to connect to ssh, and send a su command, but the problem is that when I su, I no longer in control with session, so I get stuck into the su user, my question is there a way to solve this issue ?
Regards
Well, you could use the su command with the -c option, which will run a single command and then return (pick a simple command, like hostname). Thereafter you could check the $? variable. If 0, it worked. If non-zero, it failed.
However, if su prompts for a password, then your script is going to get stuck.
sudo, on the other hand, has both a "command" parameter and a "non interactive" parameter. Would sudo work for you?
# -n = Non Interactive
# -u = Username
# -s = Command to run
sudo -n -u root -s hostname
if [ $? == 0 ]; then echo "It worked"; else echo "No good"; fi
I need to remotely start bash scripts that perform sudo tasks, such as chmod and ntpdate and echoing to gpio.
A cron job might be the best solution for some of this, but cron is giving me headaches. I'd like to pass on this venue if I can...
I've confirmed that my scripts work locally (I can ssh into the machine and run them without a hiccup.)
However, If I try to run them remotely like so: (this is within a C++ system call)
ssh user#pc 'bash -s' < /home/user/myScript.sh
Commands with sudo fail.
sudo chmod fails with: no tty present and no askpass program specified
echo to gpio fails with: write error: Device or resource busy
sudo ntpdate fails with: no tty present and no askpass program specified
Can anyone help explain, or help me determine whats happening here?
I'm open to band-aids and different approaches, thanks!
You already found the problem yourself:
sudo chmod fails with: no tty present and no askpass program specified
If you run you shell script via ssh and the script wants to run the command sudo, sudo itself will ask for the users password. But the ssh session is not a tty! How should sudo now prompt for a password and how to get your password?
You can do it if you provide the password in the script ( what makes it very dangerous if someone else can read that script! )
script.sh:
echo "your passwd" | sudo -S
As alternative solution you can run the ssh session with a more privileged user.
ssh privileged_user#pc 'bash -s' < /home/user/myScript.sh
All that comes with some danger. Running all commands from the cript with a more privileged user can also be dangerous!
I have the following bash script to restart the network manager in Debian. The script works as is it should, but not as I would like it to. When the script asks for the sudo password I am able to pass it along using echo, but it displays the password in terminal while the script executes, making it less asthetically pleasing than I would like. Is there anyway to have the script enter the password, but not display the password text while the script calls for the sudo password?
I have tried as many suggestions on Stack Overflow as i could find, well as Stack Exchange before submitting this question.
Script is as follows:
#!/bin/bash
clear
echo "Restarting service Network Manager"
echo""
sleep 1
echo -e "\033[0;31m......................................\033[0m"
echo -e "\033[0;31m......................................\033[0m"
sleep 1
echo""
sudo service network-manager restart
sleep 2
echo <Password>
sleep 2
echo "Service Network Manager Restarted"
sleep 1
echo ""
echo "Relinquishing control of terminal to user..."
sleep 7
clear
Remove the echo <Password> line? I am pretty sure it does nothing other than display the password, as sudo apparently (through an appropriate entry in /etc/sudoers) works without you having to give a password. (What you write to terminal with echo does not get passed to any other process.)
Generally speaking, you can use sudo -S to make sudo expect the password on stdin. But also generally speaking, if you have to hardcode a password in a script, you're doing it wrong in some way.
Is there anyway to have the script enter the password
Putting password in script is not a good idea. First, from security point of view, password may be recovered from script from anyone with access to script. Second, from maintenance view, once you change your password, scripts suddenly stop working and you have to update them all.
Fortunately, as you are already using sudo there is better solution. You can configure sudo to allow running certain command without password, by using NOPASSWD rule in /etc/sudoers.
myuser ALL=(ALL) NOPASSWD: service network-manager restart
See:
How do I run specific sudo commands without a password?
How to run a specific program as root without a password prompt?
Warning: Always edit /etc/sudoers with visudo, never directly. It prevents you from breaking /etc/sudoers. Once you break your /etc/sudoers, you won't be able to use sudo, including using sudo to fix /etc/sudoers.
try this /bin/echo -e "password\n" | sudo apt-get update
or see this Use sudo with password as parameter
I am creating a simple automated script. here is the code
#!/bin/sh
echo "testing expect"
/usr/bin/expect <<delim
expect "password for teamer:"
send "itsme\r"
expect eof
delim
sudo apt-get update
I refer to various documents and blogs they are using spawn. So I have question: is it necessary to use spawn every time? I am executing the update on my local machine.
Not using spawn I get this error:
send: spawn id exp0 not open while executing
or am I missing something?
expect's expect command is watching the IO channels of the spawned process waiting for the pattern to specify. If you don't give it something to watch, it will just sit there until it times out and then send the password to nothing.
This is what you need to do:
#!/bin/sh
echo "testing expect"
/usr/bin/expect <<delim
exp_internal 1 ;# remove this when your satisfied it's working
spawn sudo apt-get update
expect "password for teamer:"
send "itsme\r"
expect eof
delim
Be careful that you do not have any leading or trailing whitespace on the line with the heredoc delimiter.
If you don't care that your password is in plain text (you should), you don't need to use expect:
#!/bin/sh
echo "itsme" | sudo -S apt-get update
What you ought to do is to edit the sudoers file to allow yourself to sudo apt-get without having to supply your password, then:
#!/bin/sh
sudo apt-get update
Read the sudoers man page on your system.
In Linux how can I enter the password for one of the commands in a chain of commands which requires a sudo. One example which I can think of is when after running a long compile job, I want to shutdown the machine.
make ; sudo init 0
I want the shutdown command to run only after make finishes, but would like to enter the password right away, because I won't be there when the first command is done. Also, I don't want to run "make" with super user privileges. So switching to root and running the commands is also out of the question.
Thanks!
sudo sh -c "su -c 'make' $USER && init 0"
Change your uid early and often. That's the Chicago way!
You can run sudo -v to update the sudo timestamp - this means you won't need to enter a password for x minutes (default is 5). You can change the timeout by editing the timestamp_timeout in the sudoers file.
You also might want to change your command to
make && sudo init 0
which will only shut down if make completes successfully.
One possibility is to use Expect
to automate the password input.
Here's a simple HOW-TO for expect and passwords: http://www.linux.com/archive/feed/56066
Another possibility is to edit your /etc/sudoers and set your user to be able to use sudo without password. if you check the file it will be explained in the comments there.
Why not pipe the password into sudo?
make; echo 'password' | sudo -S init 0
Change the timeout for sudo to something long enough to cover your usage, then run something like sudo echo to authenticate, then run your other commands. As long as the password timeout hasn't been reached, it should execute without asking again.
You can add that to your sudoers file
username ALL = NOPASSWD: /sbin/init
where username is the username you want to allow.