SSH into google colab

Google Colab SSH

#CODE

#Generate root password
import random, string
password = ''.join(random.choice(string.ascii_letters + string.digits) for i in range(20))

#Download ngrok
! wget -q -c -nc https://bin.equinox.io/c/4VmDzA7iaHb/ngrok-stable-linux-amd64.zip
! unzip -qq -n ngrok-stable-linux-amd64.zip
#Setup sshd
! apt-get install -qq -o=Dpkg::Use-Pty=0 openssh-server pwgen > /dev/null
#Set root password
! echo root:$password | chpasswd
! mkdir -p /var/run/sshd
! echo "PermitRootLogin yes" >> /etc/ssh/sshd_config
! echo "PasswordAuthentication yes" >> /etc/ssh/sshd_config
! echo "LD_LIBRARY_PATH=/usr/lib64-nvidia" >> /root/.bashrc
! echo "export LD_LIBRARY_PATH" >> /root/.bashrc

#Run sshd
get_ipython().system_raw('/usr/sbin/sshd -D &')

#Ask token
print("Copy authtoken from https://dashboard.ngrok.com/auth")
import getpass
authtoken = getpass.getpass()

#Create tunnel
get_ipython().system_raw('./ngrok authtoken $authtoken && ./ngrok tcp 22 &')
#Print root password
print("Root password: {}".format(password))
#Get public address
! curl -s http://localhost:4040/api/tunnels | python3 -c \
    "import sys, json; print(json.load(sys.stdin)['tunnels'][0]['public_url'])"
    
    
    
    
#Copy authentication token after authenticating your ID using google or github and 
###./ngrok authtoken 616pgtVvEMKxN6C********************************************

Password will be generated 

How to SSH ? 
ssh [email protected] -p 10965 <-- port number dictated in colab output
passord : In colab output

You can use reverse shell method to get a shell on Colab:

1. Getting reverse shell

On local machine terminal 1, run:

$ ngrok tcp 8000

On local machine terminal 2, run:

$ nc -lvnp 8000

nc or ncat or netcat must be installed on your machine

On Colab, run:

! bash -i >& /dev/tcp/<NGROK_HOSTNAME>/<NGROK_PORT> 0>&1

2. Upgrading shell to fully interactive TTYs (recommend)

If you are on Mac and using ZSH shell, please switch to BASH shell first before running nc -lvnp 8000

On local machine terminal 2 (this terminal now should be a shell of Colab), run:

# python -c 'import pty; pty.spawn("/bin/bash")'

Press Ctrl-Z (you are now back to shell on your machine) then run:

$ stty raw -echo
$ fg

You are now back to Colab shell. if you see nothing, run:

reset

All Done!! You also can update these env variables if you want.

# export TERM=xterm-256color
# stty rows <num> columns <cols>

any idea why reverse shell exits after some time when I've switched windows?

import secrets, json, re, pathlib, getpass

This script is not fully made by me!

Parts were copied from other people.

Installing SSH server

!apt-get update > /dev/null
!apt-get install -qq -o=Dpkg::Use-Pty=0 openssh-server > /dev/null

Installing ngrok

!wget -nv -nc https://bin.equinox.io/c/4VmDzA7iaHb/ngrok-stable-linux-amd64.zip
!unzip -n ngrok-stable-linux-amd64.zip

Creating user accounts

root_password = secrets.token_urlsafe()
user_password = secrets.token_urlsafe()
user_name = "colab"
!useradd -s /bin/bash -m $user_name
!echo root:$root_password | chpasswd
!echo $user_name:$user_password | chpasswd
!usermod -aG sudo $user_name
!mkdir -p /run/sshd
!service ssh restart

Installing VNC related stuff

libjpeg_ver = "2.0.4"
virtualGL_ver = "2.6.3"
turboVNC_ver = "2.2.5"

libjpeg_url = "https://iweb.dl.sourceforge.net/project/libjpeg-turbo/{0}/libjpeg-turbo-official_{0}_amd64.deb".format(libjpeg_ver)
virtualGL_url = "https://iweb.dl.sourceforge.net/project/virtualgl/{0}/virtualgl_{0}_amd64.deb".format(virtualGL_ver)
turboVNC_url = "https://iweb.dl.sourceforge.net/project/turbovnc/{0}/turbovnc_{0}_amd64.deb".format(turboVNC_ver)

!curl -fsSL -O $libjpeg_url
!curl -fsSL -O $virtualGL_url
!curl -fsSL -O $turboVNC_url
!dpkg -i *.deb

Installing the desktop environment and some additional software

!add-apt-repository ppa:x2go/stable -y
!apt-get update
!apt-get -qq install xfce4 xfce4-terminal xfce4-taskmanager htop leafpad chromium-browser x2goserver x2goserver-xsession > /dev/null

Setting up TurboVNC

vnc_sec_conf_p = pathlib.Path("/etc/turbovncserver-security.conf")
vnc_sec_conf_p.write_text("""
no-remote-connections
no-httpd
no-x11-tcp-connections
""")

Installing Nvidia drivers

!wget -nv -nc http://us.download.nvidia.com/tesla/410.104/NVIDIA-Linux-x86_64-410.104.run
!chmod +x NVIDIA-Linux-x86_64-410.104.run
!echo 1 | ./NVIDIA-Linux-x86_64-410.104.run --no-kernel-module --ui=none

Make sure GPU is indeed working

!export LD_PRELOAD=/usr/lib64-nvidia/libnvidia-ml.so
!nvidia-smi -L

Creating a headless screen

!nvidia-xconfig -a --allow-empty-initial-configuration --virtual=1920x1080 --busid PCI:0:4:0

Edit xorg.conf so that Nvidia driver is loaded on seat-1.

with open("/etc/X11/xorg.conf", "r") as f:
conf = f.read()
conf = re.sub('(Section "Device".*?)(EndSection)', '\1 MatchSeat "seat-1"\n\2', conf, 1, re.DOTALL)

with open("/etc/X11/xorg.conf", "w") as f:
f.write(conf)

!/opt/VirtualGL/bin/vglserver_config -config +s +f

Setting up ngrok

if not pathlib.Path('/root/.ngrok2/ngrok.yml').exists():
print("---")
print("Copy and paste your tunnel authtoken from https://dashboard.ngrok.com/auth")
print("(You need to sign up for ngrok and login)")
ngrok_token = getpass.getpass()
!./ngrok authtoken $ngrok_token

print("Select your ngrok region:")
print("us - United States (Ohio)")
print("eu - Europe (Frankfurt)")
print("ap - Asia/Pacific (Singapore)")
print("au - Australia (Sydney)")
region = input()

get_ipython().system_raw("./ngrok tcp -region {} 22 &".format(region))
!sleep 1
tunnels = !curl -s http://localhost:4040/api/tunnels
url = json.loads(tunnels[0])["tunnels"][0]["public_url"]
m = re.match("tcp://(.+):(\d+)", url)
hostname = m.group(1)
port = m.group(2)
ssh_common_options = "-o UserKnownHostsFile=/dev/null -o ServerAliveInterval=60"

Give the user login credentials etc.

print("✂️"*24)
print("root password: {}".format(root_password))
print("{} password: {}".format(user_name, user_password))
print("✂️"*24)
print("---")
print("Command to connect to the ssh server:")
print("✂️"*24)
print("ssh {} -p {} {}@{}".format(ssh_common_options, port, user_name, hostname))
print("✂️"*24)
print("---")
print("If you use X2Go:")
print("✂️"*24)
print("ssh {} -L 2222:localhost:22 -p {} {}@{}".format(ssh_common_options, port, user_name, hostname))
print("✂️"*24)
print("---")
print("If you use VNC:")
print("✂️"*24)
print("ssh {} -L 5901:localhost:5901 -p {} {}@{}".format(ssh_common_options, port, user_name, hostname))
print("✂️"*24)

And finally run the Xorg server

get_ipython().system_raw("Xorg -seat seat-1 -allowMouseOpenFail -novtswitch -nolisten tcp &")

vncrun_py = pathlib.Path("vncrun.py")
vncrun_py.write_text("""
import subprocess, secrets, pathlib

vnc_passwd = secrets.token_urlsafe()[:8]
vnc_viewonly_passwd = secrets.token_urlsafe()[:8]
print("✂️"*24)
print("VNC password: {}".format(vnc_passwd))
print("VNC view only password: {}".format(vnc_viewonly_passwd))
print("✂️"*24)
vncpasswd_input = "{0}\n{1}".format(vnc_passwd, vnc_viewonly_passwd)
vnc_user_dir = pathlib.Path.home().joinpath(".vnc")
vnc_user_dir.mkdir(exist_ok=True)
vnc_user_passwd = vnc_user_dir.joinpath("passwd")
with vnc_user_passwd.open('wb') as f:
subprocess.run(
["/opt/TurboVNC/bin/vncpasswd", "-f"],
stdout=f,
input=vncpasswd_input,
universal_newlines=True)
vnc_user_passwd.chmod(0o600)

subprocess.run(
["/opt/TurboVNC/bin/vncserver"]
)
""")

!su -c'python3 vncrun.py' $user_name