Automatically enter SSH password with script

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?

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.

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!

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.

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

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

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 myusername@myserver.mydomain.com

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

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

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.

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

ssp:

#!/bin/bash

sshpass -p mypassword ssh root@$1

And therefore:

ssp server_ip

# 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

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

plink your_username@yourhost -pw your_password

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* shh 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* shh 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.

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.

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!

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/

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

I managed to get it working with that:

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

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"

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

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"

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.

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

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