Automatically enter SSH password with script

Question

I need to create a script that automatically inputs a password to OpenSSH ssh client.

Let's say I need to SSH into myname@somehost with the password a1234b.

I've already tried...

#~/bin/myssh.sh
ssh myname@somehost
a1234b

...but this does not work.

How can I get this functionality into a script?

Demagoguery

Answer 1

First you need to install sshpass.

• Ubuntu/Debian: apt-get install sshpass
• Fedora/CentOS: yum install sshpass
• Arch: pacman -S sshpass

---

Example:

sshpass -p "YOUR_PASSWORD" ssh -o StrictHostKeyChecking=no YOUR_USERNAME@SOME_SITE.COM

Custom port example:

sshpass -p "YOUR_PASSWORD" ssh -o StrictHostKeyChecking=no YOUR_USERNAME@SOME_SITE.COM:2400

Notes:

• sshpass can also read a password from a file when the -f flag is passed.
  • Using -f prevents the password from being visible if the ps command is executed.
  • The file that the password is stored in should have secure permissions.

Weismann

just be aware that while sshpass blocks your password from commands like ps -aux, you shouldn't normally run commands by typing your password because other users on the same computer may be able to see the password by running ps -aux. if practical, you also want to use public key authentication instead, as mentioned in the other answer. this allows you to separate authentication info from your script so you can share your script with others worry-free, and later decide to enable encryption on your ~/.ssh folder without also encrypting your script. – Gollin

Unfortunately this isn't working for me on a server with a custom ssh port...why can't ssh just give us the option to insert the password in the command line? – Cornwallis

Is there something equivalent for cryptsetup luksAddKey /path/to/key, which prompts Enter a passphrase: ? – Hornpipe

for custom port to work add "-p port-number" at the end of command – Ftc

Worth noting that there's still a brief window of time during which the password can be nabbed from /proc. It's still better to not use sshpass in this way. If possible, you want to pass passwords via files with strong permissions or (better yet) environment variables. – Ichthyoid

@Weismann How to do this with ssh-add instead of ssh, in order to add a key? – Endoplasm

I've added an answer with a more secure usage of sshpass. – Cholera

Good enough solution for Jenkins pipelines. – Ermina

sshpass has an option, -f, to read the password from a file. Thus, it won't be visible when using ps, and if the file has appropriate permissions in one's own home directory, it should be safe. – Timaru

@Per Mejdal Rasmussen maybe its better than using expect but as long that you don't know what is the exact situation of the OP, you cannot state that as a fact. Not everyone is living in the same environment as you are used to. For my use case expect is the solution, all the other 'better' solutions won't work in my case. – Huckaby

Not available on Windows git bash – Malherbe

why we need to pass StrictHostKeyChecking=no – Homophile

Mac OS is fun: trying brew install sshpass and got "Error: No available formula with the name "sshpass". We won't add sshpass because it makes it too easy for novice SSH users to ruin SSH's security." – Boyette

@Vladmir For Mac OS you could try installing the unofficial package. https://gist.github.com/arunoda/7790979#installing-with-homebrew – Weismann

I tried sshpass -p "nvidia" ssh -o StrictHostKeyChecking=no nvidia@"$x" "kill `pgrep ads2`" . However it didn't work. ?? – Shiller

ssshpass work well on scp too – Warrantor

Answer 2

After looking for an answer to the question for months, I finally found a better solution: writing a simple script.

#!/usr/bin/expect

set timeout 20

set cmd [lrange $argv 1 end]
set password [lindex $argv 0]

eval spawn $cmd
expect "password:"
send "$password\r";
interact

Put it to /usr/bin/exp, So you can use:

• exp <password> ssh <anything>
• exp <password> scp <anysrc> <anydst>

Done!

Infallible

This answer should get more votes imo, it is a great wrapper. Just tried a few common operations like rsyncing with various flags and remote command execution and it worked every time. Added to my toolbox of useful scripts, Thanks @damn_c! – Houle

I used this to get around having to type in a password every time I ran an Ansible script on a new server instance that did not yet have my key in ~/.ssh/authorized_keys. exp <password> ansible-playbook set-user-remove-password-login.yml -k To my great pleasure, the password was typed in when ansible prompted me with the SSH password: – Nissa

The reason why this is IMO not a very good answer is because the password is written in the script which is by far the least secure method... – Millur

@PierreE the password is specified on the command line, not in the script. – Petersburg

The password will be visible by anyone who runs ps on the machine. – Poise

Lets say you entered the wrong password using this script. Then Terminal will ask for another password a few times before your script can continue. Is there some way the script can abort entering a password if it was not correct? – Ierna

This is an extremely useful solution for non-standard ssh servers which don't work with sshpass – Firebreak

i've added log_user 0 to skip some unrequired logs – Tuesday

This answer is the best way, simple but malleable. Keep in mind you'll need to install the expect package first. Also I don't see the purpose of the timeout at the start... – Horripilate

This solution has a downside: It will break if you use SSH control sockets. In this case, you are only asked for the password if you don't already have an active connection to the server. If that connection is already there, then this expect script will sit waiting for the password prompt. IMO sshpass is a better solution for this reason alone. – Lissie

Answer 3

Use public key authentication: https://help.ubuntu.com/community/SSH/OpenSSH/Keys

In the source host run this only once:

ssh-keygen -t rsa # ENTER to every field
ssh-copy-id myname@somehost

That's all, after that you'll be able to do ssh without password.

Predella

I see. But I am REQUIRED to ssh with password. This is because, "I" may have the script on a thumb drive and need to run it from any computer; while not disabling the need for password. – Demagoguery

You can also store the private key on the said thumb drive. – Bloodthirsty

@user1467855, I think you need to better explain your requirements. Nobody is suggesting that you have an unsecure network. In the public-key approach, it would still be possible for users to log in with the password. But you would copy the private key onto your thumb drive, which means the thumb drive would be the only thing that can log in without a password. – Rolandorolandson

Unfortunately, I am in OP situation, because the sysadmin disallows authentication by rsa/dsa keys and requires passwors. What are you gonna do. – Academicism

I agree with @KarelBílek. The other options requires more skill, Python coding, expect. There is no easy option I think. – Predella

While I would normally COMPLETELY agree about using keyauth, my school's IT department is dumb and doesn't have keyauth enabled on their servers. – Navy

Thanks for demonstrating "ssh-copy-id". I was adding the IDs with the cumbersome way cat ~/.ssh/id_rsa.pub | ssh user@host "cat - >> ~/.ssh/authorized_keys". This is so much easier! – Alrzc

A quick note to anyone who found this question from Googling like I did: Try this first, if you run into some sort of signing error, try using ssh-add on your machine. That fixed my issue. – Nierman

Downvoted because this doesn't even try to answer the actual question asked. – Ichthyoid

This still prompts for the first login and cannot be used in a script! – Relapse

Using passwordless keys (you didn't even mention that is what happens when just pressing enter in response to all prompts) has the disadvantage that a major source of security leaks is accidentally backing up and exporting unencrypted key files. Obviously sometimes some critical files have to live unencrypted - one way to handle that is keep those under etc and back etc up separately from main backup. – Ammoniac

I am trying now to get this working since 10-12 hours. No luck: For another user its working but not for the one I need. Is there any solution on providing a pass in a script? – Afghani

Answer 4

You could use an expects script. I have not written one in quite some time but it should look like below. You will need to head the script with #!/usr/bin/expect

#!/usr/bin/expect -f
spawn ssh HOSTNAME
expect "login:" 
send "username\r"
expect "Password:"
send "password\r"
interact

Enclave

I did as you suggested but get the following errors: /bin/myssh.sh: 2: spawn: not found /bin/myssh.sh: 3: expect: not found /bin/myssh.sh: 4: send: not found /bin/myssh.sh: 5: expect: not found /bin/myssh.sh: 6: send: not found – Demagoguery

Thanks Aaron for modifying my answer to be correct. You may need to run the below command to find the correct path to put in for expect.which expect – Enclave

You can also use this shebang line: #!/usr/bin/env expect – Woofer

I added interact to the end so the ssh session is actually interactive – Academicism

-1 for the huge security risk of keeping a plain text password in a script. – Abreast

@AaronDigulla, how is this any less secure than any alternatives, for example the private key is also readable? Perhaps we should suggest that the script be readable only by the user? – Rolandorolandson

@AaronMcDaid Making the script only readable to a user makes it better. But root can still read it and most attackers try to get root access. Private keys are useless without passwords to unlock them. Which creates a loop since OP wanted to know how to avoid entering the password. But if he puts this script on a thumb drive, he's adding a lot of risk because thumb drives get lost or can be stolen and then, someone has access. – Abreast

Answer 5

Variant I

sshpass -p PASSWORD ssh USER@SERVER

Variant II

#!/usr/bin/expect -f
spawn ssh USERNAME@SERVER "touch /home/user/ssh_example"
expect "assword:"
send "PASSWORD\r"
interact

Chanel

No. sshpass is not ssh. SYNOPSIS sshpass [-ffilename|-dnum|-ppassword|-e] [options] command arguments – Chanel

In order to run sshpass in Linux CentOS you must yum -y install epel-release and then yum -y install sshpass – Keeshakeeshond

In this context of this data can be ignored – Chanel

While I know this is an old post it's worth noting that the Variant II method would leave the password given to the session vulnerable in the bash history, making it highly inadvisable. – Bushtit

Answer 6

sshpass with better security

I stumbled on this thread while looking for a way to ssh into a bogged-down server -- it took over a minute to process the SSH connection attempt, and timed out before I could enter a password. In this case, I wanted to be able to supply my password immediately when the prompt was available.

(And if it's not painfully clear: with a server in this state, it's far too late to set up a public key login.)

sshpass to the rescue. However, there are better ways to go about this than sshpass -p.

My implementation skips directly to the interactive password prompt (no time wasted seeing if public key exchange can happen), and never reveals the password as plain text.

#!/bin/sh
# preempt-ssh.sh
# usage: same arguments that you'd pass to ssh normally
echo "You're going to run (with our additions) ssh $@"

# Read password interactively and save it to the environment
read -s -p "Password to use: " SSHPASS 
export SSHPASS

# have sshpass load the password from the environment, and skip public key auth
# all other args come directly from the input
sshpass -e ssh -o PreferredAuthentications=keyboard-interactive -o PubkeyAuthentication=no "$@"

# clear the exported variable containing the password
unset SSHPASS

Cholera

note to self: update script to use trap to prevent ctrl-C from leaking the SSHPASS variable – Cholera

I found that PreferredAuthentications=keyboard-interactive didn't work, but replacing it with PreferredAuthentications=password worked. – Welford

I'm running ssh inside the remote machine again, with the same password. Right now I'm exporting SSHPASS into the remote machine with export SSHPASS=$SSHPASS. Is there a safer way? To provide some context, I ssh into a cluster of machines, set up ssh keys, and then distribute them into other computers in the cluster. All of that runs from a script in a single computer. So I need 2 levels of ssh. – Jankowski

This solution is only for the case where you don't have prior access to the machine to set up a key-based login. I would look at key forwarding dev.to/levivm/… – Cholera

Answer 7

sshpass + autossh

One nice bonus of the already-mentioned sshpass is that you can use it with autossh, eliminating even more of the interactive inefficiency.

sshpass -p mypassword autossh -M0 -t [email protected]

This will allow autoreconnect if, e.g. your wifi is interrupted by closing your laptop.

With a jump host

sshpass -p `cat ~/.sshpass` autossh -M0 -Y -tt -J [email protected]:22223 -p 222 [email protected]

Horsehair

Note that you can't add option -f to autossh in this combination, because when used with autossh, ssh will be *unable* to ask for passwords or passphrases. harding.motd.ca/autossh/README.txt also superuser.com/questions/1278583/… – Hygro

This seems to work at first, but since the -M0 flag disables monitoring my connection fails after a while without autossh realizing it; if I omit the flag then it also works until the connection fails, at which point my password is rejected by the server – Stilly

Note that with this solution, anyone who logs into your system can see the password using ps -ef or some such command. – Cavicorn

Answer 8

I don't think I saw anyone suggest this and the OP just said "script" so...

I needed to solve the same problem and my most comfortable language is Python.

I used the paramiko library. Furthermore, I also needed to issue commands for which I would need escalated permissions using sudo. It turns out sudo can accept its password via stdin via the "-S" flag! See below:

import paramiko

ssh_client = paramiko.SSHClient()

# To avoid an "unknown hosts" error. Solve this differently if you must...
ssh_client.set_missing_host_key_policy(paramiko.AutoAddPolicy())

# This mechanism uses a private key.
pkey = paramiko.RSAKey.from_private_key_file(PKEY_PATH)

# This mechanism uses a password.
# Get it from cli args or a file or hard code it, whatever works best for you
password = "password"

ssh_client.connect(hostname="my.host.name.com",
                       username="username",
                       # Uncomment one of the following...
                       # password=password
                       # pkey=pkey
                       )

# do something restricted
# If you don't need escalated permissions, omit everything before "mkdir"
command = "echo {} | sudo -S mkdir /var/log/test_dir 2>/dev/null".format(password)

# In order to inspect the exit code
# you need go under paramiko's hood a bit
# rather than just using "ssh_client.exec_command()"
chan = ssh_client.get_transport().open_session()
chan.exec_command(command)

exit_status = chan.recv_exit_status()

if exit_status != 0:
    stderr = chan.recv_stderr(5000)

# Note that sudo's "-S" flag will send the password prompt to stderr
# so you will see that string here too, as well as the actual error.
# It was because of this behavior that we needed access to the exit code
# to assert success.

    logger.error("Uh oh")
    logger.error(stderr)
else:
    logger.info("Successful!")

Hope this helps someone. My use case was creating directories, sending and untarring files and starting programs on ~300 servers as a time. As such, automation was paramount. I tried sshpass, expect, and then came up with this.

Peak

Answer 9

# create a file that echo's out your password .. you may need to get crazy with escape chars or for extra credit put ASCII in your password...
echo "echo YerPasswordhere" > /tmp/1
chmod 777 /tmp/1

# sets some vars for ssh to play nice with something to do with GUI but here we are using it to pass creds.
export SSH_ASKPASS="/tmp/1"
export DISPLAY=YOURDOINGITWRONG
setsid ssh [email protected] -p 22

reference: https://www.linkedin.com/pulse/youre-doing-wrong-ssh-plain-text-credentials-robert-mccurdy?trk=mp-reader-card

Ovalle

I think this article is just being sarcastic! – Thomson

sarcastic maybe? but this fine if trying to automate against systems with their default admin if you are in the process of provisioning them – Antedate

No this does not require 'expect' or 'sshpass' ... this being one of the ONLY ways to ssh with just native Debian install ... so this works without root @Antedate Also note 90% of these are just using non native programing, expect or sshpass all being the same 'answer' mine is the best ... so there ;P – Ovalle

I agree that it does not require expect / sshpass. @Ovalle didn't notice you linked your pwn article, so yeah you would know if you were sarcastic or not - but on that front I was referring to the prior comment by Yan. Personally I would try to abstain from clear text and opt for ssh keys but there is the issue of bootstrapping virgin systems - where i think this is a good option if seeding the right public keys is not an option. – Antedate

Answer 10

This is how I login to my servers.

ssp <server_ip>

• alias ssp='/home/myuser/Documents/ssh_script.sh'
• cat /home/myuser/Documents/ssh_script.sh

#!/bin/bash
sshpass -p mypassword ssh root@$1

And therefore...

ssp server_ip

Elidaelidad

It seems all of your servers have same password – Bobo

and the password is written in clear text in a script. Unsecure. – Ibex

Answer 11

I am using below solution but for that you have to install sshpass If its not already installed, install it using sudo apt install sshpass

Now you can do this,

sshpass -p *YourPassword* ssh root@IP

You can create a bash alias as well so that you don't have to run the whole command again and again. Follow below steps

cd ~

sudo nano .bash_profile

at the end of the file add below code

mymachine() { sshpass -p *YourPassword* ssh root@IP }

source .bash_profile

Now just run mymachine command from terminal and you'll enter your machine without password prompt.

Note:

1. mymachine can be any command of your choice.
2. If security doesn't matter for you here in this task and you just want to automate the work you can use this method.

Cass

Note that .bash_profile is quite often word-readable. So putting your password there is not a good idea. – Counterforce

Thank you @MartinPrikryl for addressing the issue, I have updated the note at the end so anyone who is using this solution, is also aware that password is easily readable. – Cass

Should not need sudo to edit your own .bash_profile... :/ – Luteolin

Answer 12

This is basically an extension of abbotto's answer, with some additional steps (aimed at beginners) to make starting up your server, from your linux host, very easy:

1. Write a simple bash script, e.g.:

#!/bin/bash

sshpass -p "YOUR_PASSWORD" ssh -o StrictHostKeyChecking=no <YOUR_USERNAME>@<SEVER_IP>

2. Save the file, e.g. 'startMyServer', then make the file executable by running this in your terminal:

sudo chmod +x startMyServer

3. Move the file to a folder which is in your 'PATH' variable (run 'echo $PATH' in your terminal to see those folders). So for example move it to '/usr/bin/'.

And voila, now you are able to get into your server by typing 'startMyServer' into your terminal.

P.S. (1) this is not very secure, look into ssh keys for better security.

P.S. (2) SMshrimant answer is quite similar and might be more elegant to some. But I personally prefer to work in bash scripts.

Gherardo

Answer 13

If you are doing this on a Windows system, you can use Plink (part of PuTTY).

plink your_username@yourhost -pw your_password

Mcclendon

For automatic script, don't forget the option "-no-antispoof" or the console will waiting with a message "Access granted. Press Return to begin session.". The command to be executed should be placed at the end: plink your_username@yourhost -pw your_password -no-antispoof your_command – Maintopmast

The best answer for Windows user so far. – Dislocate

PuTTY have GUI options to store password, do not need cli anymore – Bobo

Answer 14

This works:

#!/usr/bin/expect -f
spawn ssh USERNAME@SERVER "touch /home/user/ssh_example"
expect "assword:"
send "PASSWORD\r"
interact

BUT!!! If you have an error like below, just start your script with expect, but not bash, as shown here: expect myssh.sh instead of bash myssh.sh

/bin/myssh.sh: 2: spawn: not found /bin/myssh.sh: 3: expect: not found /bin/myssh.sh: 4: send: not found /bin/myssh.sh: 5: expect: not found /bin/myssh.sh: 6: send: not found

Norty

Answer 15

I got this working as follows

.ssh/config was modified to eliminate the yes/no prompt - I'm behind a firewall so I'm not worried about spoofed ssh keys

host *
     StrictHostKeyChecking no

Create a response file for expect i.e. answer.expect

set timeout 20
set node [lindex $argv 0]
spawn ssh root@node service hadoop-hdfs-datanode restart

expect  "*?assword {
      send "password\r"   <- your password here.

interact

Create your bash script and just call expect in the file

#!/bin/bash
i=1
while [$i -lt 129]    # a few nodes here
  
  expect answer.expect hadoopslave$i

  i=[$i + 1]
  sleep 5

done

Gets 128 hadoop datanodes refreshed with new config - assuming you are using a NFS mount for the hadoop/conf files

Hope this helps someone - I'm a Windows numpty and this took me about 5 hours to figure out!

Godesberg

"I'm behind a firewall so I'm not worried about spoofed ssh keys". A firewall does exactly nothing in this case. The HostKeyCheck is so you can verify the host on the other end is not a trojan Host. I.e. one that's just pretending to be where you want to connect to. If you connect to an unknown host, and do something sensitive, like write a file that has credentials or a token or enter a password, that information is now effectively public knowledge. You being behind a firewall is irrelevant. – Cereus

Answer 16

I have a better solution that inclueds login with your account than changing to root user. It is a bash script

http://felipeferreira.net/index.php/2011/09/ssh-automatic-login/

Scare

The link is broken – Luteolin

Answer 17

The answer of @abbotto did not work for me, had to do some things differently:

1. yum install sshpass changed to - rpm -ivh http://dl.fedoraproject.org/pub/epel/6/x86_64/sshpass-1.05-1.el6.x86_64.rpm
2. the command to use sshpass changed to - sshpass -p "pass" ssh user@mysite -p 2122

Phototransistor

Answer 18

Solution1：use sshpass

#~/bin/myssh.sh
sshpass -p a1234b ssh myname@somehost

You can install by

# Ubuntu/Debian
$ sudo apt-get install sshpass

# Red Hat/Fedora/CentOS
$ sudo yum install sshpass

# Arch Linux
$ sudo pacman -S sshpass

#OS X
brew install https://raw.githubusercontent.com/kadwanev/bigboybrew/master/Library/Formula/sshpass.rb

or download the Source Code from here, then

tar xvzf sshpass-1.08.tar.gz 
cd sshpass-1.08.tar.gz 
./configure
sudo make install

Solution2：Set SSH passwordless login

Let's say you need to SSH into [email protected](Remote server B) with the password 2b2b2b from [email protected](Client server A).

Generate the public key(.ssh/id_rsa.pub) and private key(.ssh/id_rsa) in A with the following commands

ssh-keygen -t rsa
[Press enter key]
[Press enter key]
[Press enter key]

Use the following command to distribute the generated public key(.ssh/id_rsa.pub) to server B under bbb‘s .ssh directory as a file name authorized_keys

ssh-copy-id [email protected]

You need to enter a password for the first ssh login, and it will be logged in automatically in the future, no need to enter it again!

ssh [email protected] [Enter]
2b2b2b

And then your script can be

#~/bin/myssh.sh
ssh myname@somehost

Shoreward

Answer 19

I managed to get it working with that:

SSH_ASKPASS="echo \"my-pass-here\""
ssh -tt remotehost -l myusername

Chancy

Answer 20

In the example bellow I'll write the solution that I used:

The scenario: I want to copy file from a server using sh script:

#!/usr/bin/expect
$PASSWORD=password
my_script=$(expect -c "spawn scp userName@server-name:path/file.txt /home/Amine/Bureau/trash/test/
expect \"password:\"
send \"$PASSWORD\r\"
expect \"#\"
send \"exit \r\"
")

echo "$my_script"

Tenon

Answer 21

What i did here is

1. ssh-keygen - generate ssh key
2. copy the public key to the remote server. You can use ssh-copy-id or you can do it manually like this cat ~/.ssh/id_rsa.pub | ssh root@ip 'cat >> ~/.ssh/authorized_keys'
3. Test it ssh root@ip

After that I add it on my .zshrc for easy use

sy-login(){
    ssh root@ip
} 

References

https://www.ssh.com/academy/ssh/copy-id

https://www.makeuseof.com/tag/beginners-guide-setting-ssh-linux-testing-setup/

Anthropologist

This is what at least two existing answers how already (and technically, it's not an answer to the question, at least not without some explanation). – Counterforce

Answer 22

Use this script tossh within script, First argument is the hostname and second will be the password.

#!/usr/bin/expect
set pass [lindex $argv 1]
set host [lindex $argv 0]
spawn ssh -t root@$host echo Hello
expect "*assword: " 
send "$pass\n";
interact"

Forepart

What does this show on top of the existing answers? Particularly those by damn_c, Lipongo or RemiZOffAlex and others... – Counterforce

script execution along with ssh #!/usr/bin/expect set pass [lindex $argv 1] set host [lindex $argv 0] spawn ssh -t root@$host sh /tmp/anyscript.sh expect "*assword: " send "$pass\n"; interact" – Forepart

Answer 23

To connect remote machine through shell scripts , use below command:

sshpass -p PASSWORD ssh -o StrictHostKeyChecking=no USERNAME@IPADDRESS

where IPADDRESS, USERNAME and PASSWORD are input values which need to provide in script, or if we want to provide in runtime use "read" command.

Witchery

What does this answer show on top of existing answers? + Never ever suggest anyone to use StrictHostKeyChecking=no without explaining the consequences. – Counterforce

Answer 24

This should help in most of the cases (you need to install sshpass first!):

#!/usr/bin/bash
read -p 'Enter Your Username: ' UserName;
read -p 'Enter Your Password: ' Password;
read -p 'Enter Your Domain Name: ' Domain;

sshpass -p "$Password" ssh -o StrictHostKeyChecking=no $UserName@$Domain

Hyponitrite

What does this show what other existing answers don't already? + Never suggest anyone to use StrictHostKeyChecking=no without explaining the security consequences. – Counterforce

I do not see any "quick and dirty" in the OP. – Counterforce

Answer 25

In linux/ubuntu

ssh username@server_ip_address -p port_number

Press enter and then enter your server password

if you are not a root user then add sudo in starting of command

Skirret