/* 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();

// Remove the comments below to improve spam resistance! 
// email addresses: 
if(!addresses) var addresses = new Array();
addresses.push("10919 10909 7551 812 478 10051 9290 355 9719 7551 812 7282 7691 7483 8689 10080 478 7282 7691 8539 8689 10080 478 5534 10080 6654 2875 355 6654 10080 7691");  // [0] m
addresses.push("10919 10909 7551 812 478 10051 9290 355 9719 7691 812 8539 7483 8689 10080 478 7282 7691 8539 8689 10080 478 5534 10080 6654 2875 355 6654 10080 7691");  // [1] k

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;
}


