cryptography.js

/*
*	Author: Jim Harris
*	Cryptography module for PannIRC
*	Module that lets users use basic cryptography
*/

exports.convertToHex = function(number) {
	var digits = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'];
	var r = number < 0 ? '-' : '';
	var n = Math.floor(Math.abs(number));
	var mult16 = 1;
	while (mult16 * 16 <= n) {
		mult16 *= 16;
	}
	while (mult16 >= 1) {
		var count = 0;
		while (n >= mult16) {
			n -= mult16;
			count++;
		}
		r += digits[count];
		mult16 /= 16;
	}
	if (r == '') r = '0';
	return r;
}

exports.decimalToHex = function(data, args, info) {
	data.bot.say(info.channel, '0x' + exports.convertToHex(args[0]));
}

exports.stringToHex = function(data, args, info) {
	var r = '0x';
	
	for (var i = 0; i < args[0].length; i++) {
		if (args[0].charAt(i) == ' ') r += ' 0x';
		else r += exports.convertToHex(args[0].charCodeAt(i));
	}

	data.bot.say(info.channel, r);
}

exports.convertToBinary = function(number) {
	var r = number < 0 ? '-' : '';
	var n = Math.floor(Math.abs(number));
	var mult2 = 1;
	while (mult2 * 2 <= n) {
		mult2 *= 2;
	}
	while (mult2 >= 1) {
		var count = 0;
		while (n >= mult2) {
			n -= mult2;
			count++;
		}
		r += count;
		mult2 /= 2;
	}
	if (r == '') r = '0';
	return r;
}

exports.caesar = function(rot, phrase, oneChar) {
	var str = phrase;
	var key = rot%26;
	var r = "";

	for (var i = 0; i < str.length; i++) {
		var n = (str.charCodeAt(i));
		var a = n >= 65 && n <= 90 ? 65 : n >= 97 && n <= 122 ? 97 : -1;
		if (a != -1) {
			n += (key);
			if (n > a + 25) {
				n -= 26;
			}	
		}
		else if (oneChar) return 0;
		r += String.fromCharCode(n);
	}
	return r;
}

exports.sayCaesar = function(data, args, info) {
	data.bot.say(info.channel, exports.caesar(args[0], args[1], false));
}

exports.vigenere = function(data, args, info) {
	var keyword = args[0];
	var plainText = args[1];
	var r = "";

	var i = 0;

	var j = 0;

	while (j < plainText.length) {
		var k = keyword.charCodeAt(i);
		var z = (k >= 65 && k <= 90) ? 90 : (k >= 97 && k <= 122) ? 122 : k+25;
		var p = plainText.charCodeAt(j);
		//r += exports.caesar(keyword.charCodeAt(i), plainText.substring(j, j+1), false);
		if (z == 90 || z == 122) {
			//var z = keyword.charCodeAt(i) >= 65 && keyword.charCodeAt(i) <= 90 ? 90 : keyword.charCodeAt(i) >= 97 && keyword.charCodeAt(i) <= 122 ? 122 : -1;
			r += exports.caesar(26-(z-keyword.charCodeAt(i))-1, plainText.substring(j, j+1), false);
			i = i >= keyword.length-1 ? 0 : i+1;
		}
		else r += plainText.charAt(j);
		j++;
	}

	data.bot.say(info.channel, r);
}