Ssh: basic but functional paramiko server

This commit is contained in:
Akemi Izuko 2024-08-25 16:33:33 -06:00
parent 1e38b26cad
commit 24760ff46d
Signed by: akemi
GPG key ID: 8DE0764E1809E9FC

View file

@ -1,81 +1,152 @@
import paramiko
import select
import socket
import threading
import subprocess
import select
import sys
import os
import pty
class CustomSSHServer(paramiko.ServerInterface):
class CustomServer(paramiko.ServerInterface):
def __init__(self, username):
self.username = username
self.event = threading.Event()
def check_auth_password(self, username, password):
# Implement your authentication logic here
# Implement proper authentication here
return paramiko.AUTH_SUCCESSFUL
if username == "user0" and password == "password0":
return paramiko.AUTH_SUCCESSFUL
elif username == "user1" and password == "password1":
return paramiko.AUTH_SUCCESSFUL
elif username == "user2" and password == "password2":
return paramiko.AUTH_SUCCESSFUL
return paramiko.AUTH_FAILED
def check_channel_request(self, kind, chanid):
return paramiko.OPEN_SUCCEEDED
if kind == "session":
return paramiko.OPEN_SUCCEEDED
return paramiko.OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED
def check_channel_pty_request(self, channel, term, width, height, pixelwidth, pixelheight, modes):
return True
def check_channel_shell_request(self, channel):
self.event.set()
return True
def check_channel_exec_request(self, channel, command):
self.event.set()
return True
def get_vm_port(username):
return 9002
user_map = {
'user0': 9000,
'user1': 9001,
'emiliko': 9002
}
return user_map.get(username)
def handle_client(client_socket, addr):
transport = paramiko.Transport(client_socket)
# transport.add_server_key(paramiko.RSAKey(filename='server.key'))
transport.add_server_key(paramiko.Ed25519Key.from_private_key_file('daemon.key'))
server = CustomSSHServer()
transport.start_server(server=server)
channel = transport.accept(20)
if channel is None:
print('*** No channel.')
return
username = transport.get_username()
vm_port = get_vm_port(username)
master, slave = pty.openpty()
channel.get_pty()
channel.invoke_shell()
ssh = subprocess.Popen(
["ssh", "-p", "9002", "root@localhost"],
shell=True,
stdin=slave,
stdout=slave,
stderr=slave,
close_fds=True
)
#ssh.wait()
# Forward data between the channel and the process
while True:
r, w, e = select.select([channel, master], [], [])
if channel in r:
data = channel.recv(1024)
if not data:
break
os.write(master, data)
if master in r:
data = os.read(master, 1024)
if not data:
break
channel.send(data)
channel.close()
ssh.terminate()
def handle_tcp_forwarding(channel, origin, destination):
try:
sock = socket.socket()
sock.connect(destination)
while True:
r, w, x = select.select([sock, channel], [], [])
if sock in r:
data = sock.recv(1024)
if len(data) == 0:
break
channel.send(data)
if channel in r:
data = channel.recv(1024)
if len(data) == 0:
break
sock.send(data)
sock.close()
channel.close()
except Exception as e:
print(f"Forwarding error: {str(e)}")
def main():
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind(('', 2222))
server_socket.listen(100)
def handle_client(client_sock):
try:
transport = paramiko.Transport(client_sock)
transport.add_server_key(paramiko.Ed25519Key.from_private_key_file('daemon.key'))
server = CustomServer(None)
transport.start_server(server=server)
# Wait for authentication to complete
server.event.wait()
username = transport.get_username()
if username is None:
print("Error: No username retrieved")
return
vm_port = get_vm_port(username)
if vm_port is None:
print(f"Error: No VM associated with user {username}")
return
channel = transport.accept(20)
if channel is None:
print("Error: Channel not established")
return
vm_transport = paramiko.Transport(("localhost", vm_port))
vm_transport.start_client()
vm_transport.auth_password('root', '')
vm_channel = vm_transport.open_session()
vm_channel.get_pty()
vm_channel.invoke_shell()
while True:
r, w, x = select.select([channel, vm_channel], [], [])
if channel in r:
data = channel.recv(1024)
if len(data) == 0:
break
vm_channel.send(data)
if vm_channel in r:
data = vm_channel.recv(1024)
if len(data) == 0:
break
channel.send(data)
channel.close()
vm_channel.close()
except paramiko.SSHException as e:
print(f"SSH error: {str(e)}")
finally:
try:
transport.close()
vm_transport.close()
except:
pass
def start_server(port=22, bind_address=''):
try:
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind((bind_address, port))
except Exception as e:
print(f"Error binding to port {port}: {str(e)}")
sys.exit(1)
while True:
client_socket, addr = server_socket.accept()
threading.Thread(target=handle_client, args=(client_socket, addr)).start()
try:
sock.listen(100)
print("Listening for connections...")
client, addr = sock.accept()
print(f"Got a connection from {addr}")
threading.Thread(target=handle_client, args=(client,)).start()
except Exception as e:
print(f"Error: {str(e)}")
if __name__ == '__main__':
main()
start_server(port=2222)