Using expect to pass a password to ssh

Malfist_12243 0
Viewed 62904

How can I use expect to send a password to an ssh connection.

say the password was p@ssword and the ssh command was ssh me@127.0.0.1

What would I do with expect to a make it input the password when it says

me@127.0.0.1's password:
?

The proper action of using an SSH key pair isn't an option because I would have to use ssh (scp) to put the key on the server, which would ask for a password.

expect cygwin ssh
6 Answers

I always used the "proper" solution, but I used expect in other situations.

Here I found following suggestion:

#!/usr/local/bin/expect
spawn  sftp  -b cmdFile user@yourserver.com
expect "password:"
send "shhh!\n";
interact
user_494070

Would it not be easier to use public key authentication and use a key with no passphrase?

As the user on the source machine do this to make an RSA key

ssh-keygen -t rsa

Now copy ~/.ssh/id_rsa.pub to the target machine and append it to the authorized_keys file of the target user

Paul_Dixon_65210

Your quickest way forward (unless you want to become a Tcl expert, which would be... unusual... in 2009) is probably to use autoexpect. Here's the man page:

http://expect.nist.gov/example/autoexpect.man.html

In short, fire up autoexpect, run your ssh session, finish up what you need to do, stop autoexpecting and then beat your keyboard over the resulting mess until it works :) I'm assuming you don't need anything more than a quick hack to get your keys sorted out and then, well it sounds like you know the score already with that.

And there's this question which already contains an example close to what you seek.

user_394430

I'm pretty sure it is not possible to do what you're trying to do. Most *nix applications that prompt for a password read from the TTY directly, not stdin, so you can't pipe the password in. You can, as others have mentioned, configure SSH to not prompt for a password, as explained here.

After I was downvoted for no apparent reason, I went and did a little more research on the expect command and discovered that it has a send_tty command that sends to /dev/tty instead of stdin, which might actually do what you want... I was previously unaware of this feature. I still recommend putting the key on the server, however.

rmeador_108610
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