Nested Ssh Using Python Paramiko

Nested SSH using Python Paramiko

Try the following edited code, it should work:

#!/usr/bin/python
#
# Paramiko
#
import paramiko
import sys
import subprocess
#
# we instantiate a new object referencing paramiko's SSHClient class
#
vm = paramiko.SSHClient()
vm.set_missing_host_key_policy(paramiko.AutoAddPolicy())
vm.connect('192.168.115.103', username='osmanl', password='xxxxxx')
#
vmtransport = vm.get_transport()
dest_addr = ('10.103.53.26', 22) #edited#
local_addr = ('192.168.115.103', 22) #edited#
vmchannel = vmtransport.open_channel("direct-tcpip", dest_addr, local_addr)
#
jhost = paramiko.SSHClient()
jhost.set_missing_host_key_policy(paramiko.AutoAddPolicy())
#jhost.load_host_keys('/home/osmanl/.ssh/known_hosts') #disabled#
jhost.connect('10.103.53.26', username='latiu', password='xxxx', sock=vmchannel)
#
stdin, stdout, stderr = jhost.exec_command("show version | no-more") #edited#
#
print stdout.read() #edited#
#
jhost.close()
vm.close()
# End

Nested SSH session with Paramiko

I managed to find a solution, but it requires a little manual work. If anyone have a better solution, please tell me.

ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect('first.com', username='luser', password='secret')

chan = ssh.invoke_shell()

# Ssh and wait for the password prompt.
chan.send('ssh second.com\n')
buff = ''
while not buff.endswith('\'s password: '):
    resp = chan.recv(9999)
    buff += resp

# Send the password and wait for a prompt.
chan.send('secret\n')
buff = ''
while not buff.endswith('some-prompt$ '):
    resp = chan.recv(9999)
    buff += resp

# Execute whatever command and wait for a prompt again.
chan.send('ls\n')
buff = ''
while not buff.endswith('some-prompt$ '):
    resp = chan.recv(9999)
    buff += resp

# Now buff has the data I need.
print 'buff', buff

ssh.close()

The thing to note is that instead of this

t = ssh.get_transport()
chan = t.open_session()
chan.get_pty()

...you want this

chan = ssh.invoke_shell()

It reminds me of when I tried to write a TradeWars script when I was a kid and gave up coding for ten years. :)

Nested SSH with Paramiko and RSA key file

You cannot use port forwarding to implement the jump, if you need to use a private key stored on the jump server.

• Either download the key to the local machine. If you do not want to physically store the key on the local machine, you can download it to memory in your Python code only. See Loading key from an SSH jumphost using Paramiko.

• Otherwise you would have to implement the jump by running ssh client on the jump server, which will pick up the private key stored there (what is normally a lame solution):

  ssh.exec_command("ssh root@Y pwd")
  

Nested SSH using Python Paramiko

Try the following edited code, it should work:

#!/usr/bin/python
#
# Paramiko
#
import paramiko
import sys
import subprocess
#
# we instantiate a new object referencing paramiko's SSHClient class
#
vm = paramiko.SSHClient()
vm.set_missing_host_key_policy(paramiko.AutoAddPolicy())
vm.connect('192.168.115.103', username='osmanl', password='xxxxxx')
#
vmtransport = vm.get_transport()
dest_addr = ('10.103.53.26', 22) #edited#
local_addr = ('192.168.115.103', 22) #edited#
vmchannel = vmtransport.open_channel("direct-tcpip", dest_addr, local_addr)
#
jhost = paramiko.SSHClient()
jhost.set_missing_host_key_policy(paramiko.AutoAddPolicy())
#jhost.load_host_keys('/home/osmanl/.ssh/known_hosts') #disabled#
jhost.connect('10.103.53.26', username='latiu', password='xxxx', sock=vmchannel)
#
stdin, stdout, stderr = jhost.exec_command("show version | no-more") #edited#
#
print stdout.read() #edited#
#
jhost.close()
vm.close()
# End

Loading key from an SSH jumphost using Paramiko

Yes. You have to have all credentials locally. The port forwarding alone does not make credentials stored on the intermediate hosts available for authentication.

Of course, you can use SFTP to access/download the files/keys, like:

sftp3 = ssh3.open_sftp()

with sftp3.open(".ssh/id_rsa") as key_file:
    pkey = RSAKey.from_private_key(key_file)

ssh4.connect(host4, username=host4_username, sock=vmchannel, pkey=pkey)

---

Related Topics