SSH_ASKPASS

$ man ssh

...

SSH_ASKPASS

If ssh needs a passphrase, it will read the

passphrase from the current terminal if it was run

from a terminal. If ssh does not have a terminal

associated with it but DISPLAY and SSH_ASKPASS are

set, it will execute the program specified by

SSH_ASKPASS and open an X11 window to read the

passphrase. This is particularly useful when call‐

ing ssh from a .xsession or related script. (Note

that on some machines it may be necessary to redi‐

rect the input from /dev/null to make this work.)

...

Keep in mind that ssh stands for secure shell, and if you store your user, host and password in plain text files you are misleading the tool an creating a possible security gap

$ cat ~/echo_pass

echo toor

$

$ cat ssh_session

export SSH_ASKPASS='~/echo_pass'

setsid ssh root@127.0.0.1

$ chmod u+x echo_pass

$ chmod u+x ssh_session

 ./ssh_session

$ ./ssh_session

Welcome to Ubuntu 18.04.5 LTS (GNU/Linux 4.15.0-121-generic x86_64)

operator@server:~$

https://stackoverflow.com/questions/1340366/how-to-make-ssh-receive-the-password-from-stdin

SSH_ASKPASS

 

#!/bin/bash

hostname="127.0.0.1"

username="u"

password="p"

command='ls -l'

ask="/tmp/ask"

echo "echo $password" > $ask

chmod +x $ask

SSH_OPTIONS='-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null'

SSH_ASKPASS=$ask

DISPLAY=localhost:0.0

export DISPLAY

export SSH_ASKPASS

setsid ssh $SSH_OPTIONS $username@$hostname $command && echo '\n SSH OK\n' || echo '\nSSH PROBLEM\n'

Python SSHClient invoke interactive shell

...

import threading, paramiko

class ssh:

shell = None

client = None

transport = None

def __init__(self, address, username, password):

print("Connecting to server on ip", str(address) + ".")

self.client = paramiko.client.SSHClient()

self.client.set_missing_host_key_policy(paramiko.client.AutoAddPolicy())

self.client.connect(address, username=username, password=password, look_for_keys=False)

self.transport = paramiko.Transport((address, 22))

self.transport.connect(username=username, password=password)

thread = threading.Thread(target=self.process)

thread.daemon = True

thread.start()

def closeConnection(self):

if(self.client != None):

self.client.close()

self.transport.close()

def openShell(self):

self.shell = self.client.invoke_shell()

def sendShell(self, command):

if(self.shell):

self.shell.send(command + "\n")

else:

print("Shell not opened.")

def process(self):

global connection

while True:

# Print data when available

if self.shell != None and self.shell.recv_ready():

alldata = self.shell.recv(1024)

while self.shell.recv_ready():

alldata += self.shell.recv(1024)

strdata = str(alldata, "utf8")

strdata.replace('\r', '')

print(strdata, end = "")

if(strdata.endswith("$ ")):

print("\n$ ", end = "")

sshUsername = ''

sshPassword = ''

sshServer = ''

connection = ssh(sshServer, sshUsername, sshPassword)

connection.openShell()

while True:

connection.sendShell('./script.sh')

command = input('$ ')

if command.startswith(" "):

command = command[1:]

connection.sendShell(command)

https://daanlenaerts.com/blog/2016/07/01/python-and-ssh-paramiko-shell/

Python, paramiko, SSHClient, invoke_shell() in bytes

from paramiko import SSHClient, AutoAddPolicy

hostname = '127.0.0.1'

username = 'admin'

password = 'password'

client = SSHClient()

client.set_missing_host_key_policy(AutoAddPolicy())

client.connect(hostname, port = 22,

username = username,

password = password,

look_for_keys = False,

allow_agent = False)

device_access = client.invoke_shell()

device_access.send(b'ls -lh\n')

output = device_access.recv(65000)

print(output.decode('ascii'))

client.close

Alpine Linux

1. Download

https://alpinelinux.org/downloads/

2. Login with root

3. Change the password

passwd

4. Set temporary IP (static or dhcp)

ifconfig eth0 10.1.1.1

or

udhcpc -i eth0

5. Install the openssh package

apk add openssh

5. View/change SSH config

/etc/ssh/sshd_config

6. Start SSH service

/etc/init.d/sshd start