do_encrypt_rc4.js

function do_encrypt_rc4(src, passwd) {
	src = $.trim(src+'');
	passwd = passwd + '';
	var i, j = 0, a = 0, b = 0, c = 0, temp;
	var plen = passwd.length,
		size = src.length;

	var key = Array(256); //int
	var sbox = Array(256); //int
	var output = Array(size); //code of data
	for (i = 0; i < 256; i++) {
        key[i] = passwd.charCodeAt(i % plen);
		sbox[i] = i;
	}
	for (i = 0; i < 256; i++) {
		j = (j + sbox[i] + key[i]) % 256;
		temp = sbox[i];
		sbox[i] = sbox[j];
		sbox[j] = temp;
	}
	for (i = 0; i < size; i++) {
		a = (a + 1) % 256;
		b = (b + sbox[a]) % 256;
		temp = sbox[a];
		sbox[a] = sbox[b];
		sbox[b] = temp;
		c = (sbox[a] + sbox[b]) % 256;
		temp = src.charCodeAt(i) ^ sbox[c]
		temp = temp.toString(16);
		if (temp.length === 1) {
			temp = '0' + temp;
		} else if (temp.length === 0) {
			temp = '00';
		}
		output[i] = temp;
	}
	return output.join('');
}