Is it possible to automate ssh login WITH passwd (not passphraseless ssh)

Question

Regardless of security issues, I want to automate ssh login by putting password into a script file (in form of plaintext). For example, I tried following, but without success...

echo "mypassword" | ssh -X root@remote_node_address

it still prompt with password inputs...

Edit: I am aware of setting up passphraseless ssh (and actually have done this). What my question really is is how to automate process of setting up passphraseless ssh...

Answer 1

Automate with Expect

You can use Expect to drive password authentication with SSH. For example:

#!/usr/bin/expect -f
set timeout -1
spawn ssh -o PubkeyAuthentication=no host.example.com
expect -exact "Password: "
send -- "secret\r"
expect {\$\s*} { interact }

This script is a very basic example, and not especially robust in the face of failure or when running under a non-standard remote TERM like GNU screen, but it works for the common case. You can also use /usr/bin/autoexpect from the expect-dev package to generate your own custom scripts based on a manual session.

Answer 2

you will need to use public key authentication, see

http://www.ece.uci.edu/~chou/ssh-key.html

in order to add new keys for existing hosts, you will need to automate updating of public keys in ~/.ssh/authorized_keys on remote machine

it is easy to do with

ssh-keygen -t rsa -b 1024 -f ~/.ssh/new-key -P ""
cat ~/.ssh/new-key.pub | ssh root@target-host 'cat >> ~/.ssh/authorized_keys'

then you can use new key to access host with

ssh -i ~/.ssh/new-key root@remote-host