defword cipher
    3 ref as cipher.byte
    2 get as cipher.password
    1 get as cipher.len
    0 get as cipher.pos
    cipher.pos @ cipher.password + @ cipher.byte @ xor cipher.byte !
    cipher.pos @ 1 + cipher.pos !
    cipher.pos @ cipher.len = if 0 cipher.pos ! fi
    drop drop drop
exit