package require Tk

set answer {}

set yesno 0

set rc 255

if {$argc < 1} {

set prompt "Enter your OpenSSH passphrase:"

} else {

set prompt [join $argv " "]

if {[regexp -nocase {\(yes\/no\)\?\s*$} $prompt]} {

set yesno 1

}

}

message .m -text $prompt -justify center -aspect 4000

pack .m -side top -fill x -padx 20 -pady 20 -expand 1

entry .e -textvariable answer -width 50

pack .e -side top -fill x -padx 10 -pady 10

if {!$yesno} {

.e configure -show "*"

}

frame .b

button .b.ok -text OK -command finish

button .b.cancel -text Cancel -command cancel

pack .b.ok -side left -expand 1

pack .b.cancel -side right -expand 1

pack .b -side bottom -fill x -padx 10 -pady 10

bind . <Visibility> {focus -force .e}

bind . <Key-Return> [list .b.ok invoke]

bind . <Key-Escape> [list .b.cancel invoke]

bind . <Destroy> {set rc $rc}

proc cancel {} {

set ::rc 255

}

proc finish {} {

if {$::yesno} {

if {$::answer ne "yes" && $::answer ne "no"} {

tk_messageBox -icon error -title "Error" -type ok \

-message "Only 'yes' or 'no' input allowed."

return

}

}

puts $::answer

set ::rc 0

}

wm title . "OpenSSH"

tk::PlaceWindow .

vwait rc

exit $rc