arrispwgen.js

/*
 * Arris TM602A password of the day generator
 * 
 * Author: Raul Pedro Fernandes Santos
 * Project homepage: http://www.borfast.com/projects/arrispwgen
 * 
 * This software is distributed under the Simplified BSD License.
 * 
 * Copyright 2011 Raul Pedro Fernandes Santos. All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 */

// TODO: Add some unit testing, just for fun.

function GenArrisPasswords(startdate, enddate) {
	"use strict";
	
	var password_count = 0;
	var one_day_in_milliseconds = 24 * 60 * 60 * 1000; // 1 day in milliseconds

	// Check how many passwords we're going to generate.
	if (arguments.length === 2) {
		password_count = Math.ceil((enddate - startdate + 1) / one_day_in_milliseconds);
	} else if (arguments.length === 1) {
		password_count = 1;
	}

	// See if we have a valid number of passwords
	if ((password_count < 1) || (password_count > 365)) {
		throw 'Invalid dates. I need dates that span a year at most';
	}
  
  
	var seed = 'MPSJKMDHAI';
	var seedeight = seed.substr(0, 8);
	var seedten = seed;

	var table1 = [
		[15, 15, 24, 20, 24],
		[13, 14, 27, 32, 10],
		[29, 14, 32, 29, 24],
		[23, 32, 24, 29, 29],
		[14, 29, 10, 21, 29],
		[34, 27, 16, 23, 30],
		[14, 22, 24, 17, 13]
	];

	var table2 = [
		[0, 1, 2, 9, 3, 4, 5, 6, 7, 8],
		[1, 4, 3, 9, 0, 7, 8, 2, 5, 6],
		[7, 2, 8, 9, 4, 1, 6, 0, 3, 5],
		[6, 3, 5, 9, 1, 8, 2, 7, 4, 0],
		[4, 7, 0, 9, 5, 2, 3, 1, 8, 6],
		[5, 6, 1, 9, 8, 0, 4, 3, 2, 7]
	];

	var alphanum = [
		'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
		'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R',
		'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
	];

	var list1 = [];
	var list2 = [];
	var list3 = [];
	var list4 = [];
	var list5 = [];    
	var year;
	var month;
	var day_of_month;
	var day_of_week;
	var iter, i;
	var date;

	// Now let's generate one password for each day
	var password_list = {};
	for (iter = 0; iter < password_count; iter++) {
		// For each iteration advance the date one day
		date = new Date(startdate + (iter * one_day_in_milliseconds));

		// Last two digits of the year
		year = parseInt(date.getFullYear().toString(10).substr(2, 2), 10);

		// Number of the month (no leading zero; January == 0)
		month = date.getMonth() + 1;

		// Day of the month
		day_of_month = date.getDate();

		// Day of the week. Normally 0 would be Sunday but we need it to be Monday.
		day_of_week = date.getDay() - 1;
		if (day_of_week < 0) {
			day_of_week = 6;
		}
		

		// Now build the lists that will be used by each other.

		// list1
		for (i = 0; i <= 4; i++) {
			list1[i] = table1[day_of_week][i];
		}
		list1[5] = day_of_month;
		if (((year + month) - day_of_month) < 0) {
			list1[6] = (((year + month) - day_of_month) + 36) % 36;
		} else {
			list1[6] = ((year + month) - day_of_month) % 36;
		}
		list1[7] = (((3 + ((year + month) % 12)) * day_of_month) % 37) % 36;

		// list2
		for (i = 0; i <= 7; i++) {
			list2[i] = (seedeight.substr(i, 1).charCodeAt(0)) % 36;
		}

		// list3
		for (i = 0; i <= 7; i++) {
			list3[i] = (((list1[i] + list2[i])) % 36);
		}
		list3[8] = (list3[0] + list3[1] + list3[2] + list3[3] + list3[4] +
		list3[5] + list3[6] + list3[7]) % 36;
		var num8 = (list3[8] % 6);
		list3[9] = Math.round(Math.pow(num8, 2));

		// list4
		for (i = 0; i <= 9; i++) {
			list4[i] = list3[table2[num8][i]];
		}

		// list5
		for (i = 0; i <= 9; i++) {
			list5[i] = ((seedten.substr(i, 1).charCodeAt(0)) + list4[i]) % 36;
		}


		// Finally, build the password of the day.
		var password_of_the_day = [];
		var len = list5.length;
		for (i = 0; i < len; i++) {
			password_of_the_day[i] = alphanum[list5[i]];
		}
		password_list[date.getTime()] = password_of_the_day.join('');
	}

	return password_list;
}