View source for Secure Shell - auto login ssh

The OpenSSH ssh utility doesn't accept a password on the command line or on its standard input.  The nanny mentality whereby the developer protects us from ourselves by preventing us from doing something that compromises security, even though the result may be worse.

OPTIONS FOR SSH AUTOMATED
# Use an SSH key for authentication, instead of a password.
# Use sshpass, expect, or a similar tool to automate responding to the password prompt.
# Use the SSH_ASKPASS feature to get ssh to get the password by running another program.
# Use the insecure host-based authentication, sometimes common on private networks.
# Use a custom or modified ssh client adapted from source code, or one that allows for stored password.

=== sshpass ===
Install the sshpass utility so that you can automate ssh login including password.
 apt install sshpass
Now you can automate the login process
 sshpass -p "mysecretpass" ssh -o StrictHostKeyChecking=no nicolep@192.168.100.10
Custom port example:
 sshpass -p "mysecretpass" ssh -o StrictHostKeyChecking=no nicolep@192.168.100.10:9600

=== public key authentication ===
BEFORE MAKING NEW KEY PAIRS: ''Try to Find an Existing Secure Shell Key Pair. See if you already have a .ssh under your home directory.  If you already have a key pair then you should not need to make a new key pair.''

In the source host run this only once:
 ssh-keygen -t rsa 
Now you've generated the public key.  It needs to be copied onto the remote host.  
 ssh-copy-id -i ~/.ssh/id_rsa.pub nicolep@192.168.100.10
add identities to the ssh-agent – the authentication agent on the local host.
 ssh-add
now press ENTER to every field
 ssh-copy-id nicolep@192.168.100.10

=== expect ===
Example script
 #!/usr/bin/expect
 
 set timeout 15
 
 set cmd [lrange $argv 1 end]
 set password [lindex $argv 0]
 
 eval spawn $cmd
 expect "assword:"
 send "$password\r";
 interact

Another example
 #!/usr/bin/expect -f
 #  ./ssh.exp password 192.168.100.10 id
 set pass [lrange $argv 0 0]
 set server [lrange $argv 1 1]
 set name [lrange $argv 2 2]
 
 spawn ssh $name@$server
 match_max 100000
 expect "*?assword:*"
 send -- "$pass\r"
 send -- "\r"
 interact

And finally, a more elaborate example can be found here:
* http://www.techpaste.com/2016/02/ssh-login-with-password/