WhatsApp Desktop Client Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

class Func
{
    public static bool isShort(string value)
    {
        return value.Length < 256;
    }

    public static int strlen_wa(string str)
    {
        int len = str.Length;
        if (len >= 256)
            len = len & 0xFF00 >> 8;
        return len;
    }

    public static string _hex(int val)
    {
        return (val.ToString("X").Length % 2 == 0) ? val.ToString("X") : ("0" + val.ToString("X"));
    }

    public static string random_uuid()
    {
        var mt_rand = new Random();
        return string.Format("{0}{1}-{2}-{3}-{4}-{5}{6}{7}",
                                mt_rand.Next(0, 0xffff), mt_rand.Next(0, 0xffff),
                                mt_rand.Next(0, 0xffff),
                                mt_rand.Next(0, 0x0fff) | 0x4000,
                                mt_rand.Next(0, 0x3fff) | 0x8000,
                                mt_rand.Next(0, 0xffff), mt_rand.Next(0, 0xffff), mt_rand.Next(0, 0xffff)
            );
    }

    public static string strtohex(string str)
    {
        string hex = "0x";
        for (int i = 0; i < str.Length; i++)
            hex += ((int)str[i]).ToString("x");
        return hex;
    }

    public static string HexString2Ascii(string hexString)
    {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i <= hexString.Length - 2; i += 2)
        {
            sb.Append(Convert.ToString(Convert.ToChar(Int32.Parse(hexString.Substring(i, 2), System.Globalization.NumberStyles.HexNumber))));
        }
        return sb.ToString();
    }

    public static long GetUnixTimestamp(DateTime value)
    {
        TimeSpan span = (value - new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc));
        return (long)span.TotalSeconds;
    }
    public static long GetNowUnixTimestamp()
    {
        return GetUnixTimestamp(DateTime.UtcNow);
    }

    public static bool ArrayEqual(byte[] b1, byte[] b2)
    {
        int len = b1.Length;
        if (b1.Length != b2.Length)
            return false;
        for (int i = 0; i < len; i++)
        {
            if (b1[i] != b2[i])
                return false;
        }
        return true;
    }
}