This Gist contains the way to get current wifi SSID and Password from a Mac OS X terminal

password.sh

#!/bin/bash

# Usage ./password Name_Of_The_Wi-Fi_Network
# This script returns the password of the wireless SSID in input
echo "Wi-Fi SSID: $1"
ESCAPED=$(echo $1 | sed "s/'/\\\'/g" | sed "s/[ ]/\\\\ /g")
sudo security find-generic-password -ga ${ESCAPED} | sed -n -e 's/^.password: //p'

ssid.sh

#!/bin/bash

# This line returns the current SSID to which we are connected to

/System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport -I | sed -n -e 's/^.[ \t]*SSID: //p'