how to hide ssh expect user/password

Question

My Expect script shows password/user in clear text and I want to hide it.

#!/usr/local/bin/expect
###########################################################################################    ############
# Input: It will handle two arguments -> a device and a show command.
###########################################################################################    ############
# ######### Start of Script ######################
# #### Set up Timeouts - Debugging Variables
log_user 0
set timeout 10
set userid  "USER"
set password  "PASS"
# ############## Get two arguments - (1) Device (2) Command to be executed
set device  [lindex $argv 0] 
set command [lindex $argv 1]
spawn /usr/local/bin/ssh -l $userid $device
match_max [expr 32 * 1024]
expect {
    -re "RSA key fingerprint" {send "yes\r"}
    timeout {puts "Host is known"}
}
expect {
    -re "username: " {send "$userid\r"} 
    -re "(P|p)assword: " {send "$password\r"}
     -re "Warning:" {send "$password\r"}
    -re "Connection refused" {puts "Host error -> $expect_out(buffer)";exit}
    -re "Connection closed"  {puts "Host error -> $expect_out(buffer)";exit}
   -re "no address.*" {puts "Host error -> $expect_out(buffer)";exit}
    timeout {puts "Timeout error. Is device down or unreachable?? ssh_expect";exit}
}
expect {
   -re "\[#>]$" {send "term len 0\r"}
   timeout {puts "Error reading prompt -> $expect_out(buffer)";exit}
}
expect {
   -re "\[#>]$" {send "$command\r"}
   timeout {puts "Error reading prompt -> $expect_out(buffer)";exit}
}
expect -re "\[#>]$"
set output $expect_out(buffer)
send "exit\r"
puts "$output\r\n"

Answer 1

The same issue exists in any scripting language. The script can't type in your password if it doesn't know it... the easiest solution is to use passwordless ssh, using keys.

Answer 2

... and add -OUseBatchMode=Yes so that if there is a problem with your keys, ssh will fail immediately (you can verify exit code) rather than just falling back to password mode and hanging (as you are running interactively)

Answer 3

Have a look at Glenn's answer here: http://stackoverflow.com/questions/681928/how-can-i-make-an-expect-script-prompt-for-a-password

I was trying to do the same sort of thing and found this useful.