/* EMAIL ENCRYPTION SCRIPT */

// This script is (c) copyright 2008 by Dan Appleman under the
// GNU General Public License (http://www.gnu.org/licenses/gpl.html)
// This script is modified from an original script by Jim Tucek
// For more information, visit www.danappleman.com 
// Leave the above comments alone!
// see encryption_instructions.txt for explanation of usage

var decryption_cache = new Array();

function decrypt_string(crypted_string,n,decryption_key,just_email_address) {
    var cache_index = "'"+crypted_string+","+just_email_address+"'";

    if(decryption_cache[cache_index])// If this string has already been decrypted, just
	return decryption_cache[cache_index];// return the cached version.

    if(addresses[crypted_string])// Is crypted_string an index into the addresses array
	var crypted_string = addresses[crypted_string];// or an actual string of numbers?

    if(!crypted_string.length)// Make sure the string is actually a string
	return "Error, not a valid index.";

    if(n == 0 || decryption_key == 0) {// If the decryption key and n are not passed to the
	var numbers = crypted_string.split(' ');// function, assume they are stored as the first two
	n = numbers[0];decryption_key = numbers[1];// numbers in crypted string.
	numbers[0] = ""; numbers[1] = "";// Remove them from the crypted string and continue
	crypted_string = numbers.join(" ").substr(2);
    }

    var decrypted_string = '';
    var crypted_characters = crypted_string.split(' ');

    for(var i in crypted_characters) {
	var current_character = crypted_characters[i];
	var decrypted_character = exponentialModulo(current_character,n,decryption_key);
	if(just_email_address && i < 7)// Skip 'mailto:' part
	    continue;
	if(just_email_address && decrypted_character == 63)// Stop at '?subject=....'
	    break;
	decrypted_string += String.fromCharCode(decrypted_character);
    }
    decryption_cache[cache_index] = decrypted_string;// Cache this string for any future calls

    return decrypted_string;
}

function decrypt_and_email(crypted_string,n,decryption_key) {
    if(!n || !decryption_key) { n = 0; decryption_key = 0; }
    if(!crypted_string) crypted_string = 0;

    var decrypted_string = decrypt_string(crypted_string,n,decryption_key,false);
    parent.location = decrypted_string;
}

function decrypt_and_echo(crypted_string,n,decryption_key) {
    if(!n || !decryption_key) { n = 0; decryption_key = 0; }
    if(!crypted_string) crypted_string = 0;

    var decrypted_string = decrypt_string(crypted_string,n,decryption_key,true);
    document.write(decrypted_string);
    return true;
}

// Finds base^exponent % y for large values of (base^exponent)
function exponentialModulo(base,exponent,y) {
    if (y % 2 == 0) {
	answer = 1;
	for(var i = 1; i <= y/2; i++) {
	    temp = (base*base) % exponent;
	    answer = (temp*answer) % exponent;
	}
    } else {
	answer = base;
	for(var i = 1; i <= y/2; i++) {
	    temp = (base*base) % exponent;
	    answer = (temp*answer) % exponent;
	}
    }
    return answer;
}

// Remove the comments below to improve spam resistance! 
// email addresses: 

if(!addresses) var addresses = new Array();
addresses.push("31099 31091 18621 15750 861 3902 2752 5193 3130 2752 861 18621 9498 26006 5193 28890 861 11704 4556 15750 21295 81 28996 26006 20534 24216 20534 28996 26006 20534 9498 19654 20534 9498 20534 15750");  // [0] tim.robishaw - at - nrc-cnrc.gc.ca