I wrote a SSH server with Twisted Conch. When I execute "ssh username#xx.xx.xx.xx" command on the client side. My twisted SSH server will return a prompt requesting password that like "username#xx.xx.xx.xx's password: ".
But now I want to change this password prompt that like "your codes is:". Dose anyone know how to do it?
The password prompt is part of keyboard-authentication which is part of the ssh protocol and thus cannot be changed. Technically, the prompt is actually client side. However, you can bypass security (very bad idea) and then output "your codes is"[sic] via the channel
Related
I am trying to connect a remote server using Paramiko and send some files to other remote server. I tried the code below, but it didn't work. I checked all connections, username and password parameters, they don't have any problem. Also the file which I want to transfer exist in first remote server in proper path.
The reason why I don't download files to my local computer and upload to second server is, connection speed between two remote servers is a lot faster.
Things that I tried:
I set paramiko log level to debug, but couldn't find any useful information.
I tried same scp command from first server to second server from command line, worked fine.
I tried to log by data = stdout.readlines() after stdin.flush() line but that didn't log anything.
import paramiko
s = paramiko.SSHClient()
s.set_missing_host_key_policy(paramiko.AutoAddPolicy())
s.connect("10.10.10.10", 22, username='oracle', password='oracle', timeout=4)
stdin, stdout, stderr = s.exec_command(
"scp /home/oracle/myFile.txt oracle#10.10.10.20:/home/oracle/myFile.txt")
stdin.write('password\n')
stdin.flush()
s.close()
You cannot write a password to the standard input of OpenSSH scp.
Try it in a shell, it won't work either:
echo password | scp /home/oracle/myFile.txt oracle#10.10.10.20:/home/oracle/myFile.txt
OpenSSH tools (including scp) read the password from a terminal only.
You can emulate the terminal by setting get_pty parameter of SSHClient.exec_command:
stdin, stdout, stderr = s.exec_command("scp ...", get_pty=True)
stdin.write('password\n')
stdin.flush()
Though enabling terminal emulation can bring you unwanted side effects.
A way better solution is to use a public key authentication. There also other workarounds. See How to pass password to scp? (though they internally have to do something similar to get_pty=True anyway).
Other issues:
You have to wait for the command to complete. Calling s.close() will likely terminate the transfer. Using stdout.readlines() will do in most cases. But it may hang, see Paramiko ssh die/hang with big output.
Do not use AutoAddPolicy – You are losing a protection against MITM attacks by doing so. For a correct solution, see Paramiko "Unknown Server".
In my script, I need to do an SSH to a remote system using a private key and dump the file into its directory.
The command I am using to SSH into the system is this:
ssh -i private_key localhost
Followed by the standard input:
Enter passphrase for key 'private_key'
I am trying to do this in a Python script, but am not sure about the way of writing a command and passing a passphrase as a parameter so that the whole sequence can be automated.
Please suggest me a way to achieve this via a library (Paramiko SSHClient) or a code snippet would be highly really appreciated.
SSHClient.connect can handle public key authentication with a simple call:
import paramiko
ssh = paramiko.SSHClient()
ssh.connect(hostname, username=username, key_filename=key_path, password=passphrase)
The password argument is used as a passphrase, when key_filename is provided.
Additionally, you will also have to verify the server's host key (as you must have done with ssh before). See Paramiko "Unknown Server".
I'm trying to SSH into a Raspberry Pi on a subnet via ethernet using the Fabric module but I can't figure out how to authenticate the connection.
My code so far is as follows
import fabric
c = fabric.Connection(host = "192.168.3.151", port = 22, user = "pi")
c.run("touch Desktop/new_file.txt")
Obviously I haven't put in my password, "Raspberry", anywhere in the above code to authenticate the SSH connection. I've been trying to understand the Fabric documentation but it's a little beyond me so I'm hoping someone can tell me how to input the password to authenticate the connection (and also authenticate any commands using sudo).
Thanks!
Okay, it looks like you can pass options to the Connection constructor that will be passed on to SSHClient.connect
c = fabric.Connection("192.168.3.151", port=22, user="pi", connect_kwargs={'password': 'raspberry'})
Note it's generally a bad idea to store your passwords in plain text, especially in code.
See http://docs.fabfile.org/en/2.1/concepts/authentication.html as well as http://docs.fabfile.org/en/2.1/concepts/configuration.html
This is my python script to connect to server. But when I run the script, it is asking me to keying my ssh passphrase. How could I avoid to asking my ssh passphrase key?
host = '192.168.43.3'
user = 'root'
passwd = 'ppawd'
ssh = paramiko.SSHClient()
ssh.load_system_host_keys()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect(host, username=user, password=passwd)
transport = ssh.get_transport()
channel = transport.open_session()
channel.setblocking(1)
channel.settimeout(30)
command = "ls -a"
ssh.exec_command(command)
I ran into the same issue. I don't think the other answers here realized what the question was actually for. This is an old question but I wanted to help anyone else like me who ended up here after googling.
You need to disable the ssh agent feature allow_agent=False and then it will no longer prompt you for a passphrase. Paramiko is trying to connect to the ssh agent and I assume trying to read the key. I also added look_for_keys=False, as it will disable checking for private keys to use.
Example:
client.connect(server, port=port, username=username, password=password, look_for_keys=False, allow_agent=False)
My advice would be generating a key without a passphrase - just press enter when asked for a password while creating the key.
This key should be used specifically for your script - avoid re-using keys you use for other purposes (such as your user's interactive login), since it makes key revocation and access control harder.
A passphrase-less key has some advantages compared to hardcoding the password in your script:
The presence of a passphrase-less key makes it clear to anyone that the key is compromised as soon as anyone has access to it. Separating the password from the key hides this fact without providing any additional security.
It avoids you publishing your password to source-control accidentally (separation of source code and access control credentials)
Possibly, it'll make it less tempting to re-use any existing user's ssh key with a proper passphrase.
A few security considerations:
Remember that anyone with access to that key will get access to the remote system. You may consider putting restrictive permissions on the key file, and create a separate user for your script to login into in the remote system, if it's possible at all.
If your script is single purpose, you may also consider limiting the list of shell commands available to the user on the remote system
If you have no physical security on the system that stores the key (i.e.: a laptop or desktop in a untrusted location), you may also want to use full disk encryption, block device encryption (LUKS) or file-level encryption (encfs).
I solved the problem as
ssh-copy-id root#192.168.43.133
Credit to http://sshmenu.sourceforge.net/articles/key-setup.html
You can add the fingerprint to each server's known_hosts. For a single user:
cat ~/.ssh/known_hosts
echo "$SERVER,$PORT ssh-rsa $SERVER_KEY_FINGERPRINT" >> ~/.ssh/known_hosts
add your connection host ip to known_hosts then it will not ask for any questions like
Are you sure you want to continue connecting (yes/no)?
or if u want to disable the password asking too, then check this links
http://www.linuxproblem.org/art_9.html
https://www.debian.org/devel/passwordlessssh
Is it possible to telnet to a server and from there telnet to another server in python?
Since there is a controller which I telnet into using a username and password, and from the controller command line I need to login as root to run linux command. How would I do that using python?
I use the telentlib to login into router controller but from the router controller I need to log in again to get into shell. Is this possible using python?
Thanks!
Just checked it with the hardware I have in hand & telnetlib. Saw no problem.
When you are connected to the first device just send all the necessary commands using telnet.write('cmd'). It may be sudo su\n, telnet 192.168.0.2\n or whatever else. Telnetlib keeps in mind only its own telnet connection, all secondary connections are handled by the corresponding controllers.
Have you looked into using expect (there should be a python binding); basically, what I think you want to do is:
From your python script, use telnetlib to connect to server A (pass in username/password).
Within this "socket", send the remaining commands, e.g. "telnet serverB" and use expect (or some other mechanism) to check that you get back the expected "User:" prompt; if so, send user and then password and then whatever commands, and otherwise handle errors.
This should be very much doable and is fairly common with older stuff that doesn't support a cleaner API.
You can use write() to issue the sudo command.
tn.write("sudo\n")
You could also use read_until() to help with the credentials.
tn.read_until("login: ")
tn.write(user + "\n")
if password:
tn.read_until("Password: ")
tn.write(password + "\n")