TigerEmu/Security/HabboEncryption.cs

using Tiger.Utils;

namespace Tiger.Security;

public static class HabboEncryption
{
    public static string GenerateKey()
    {
        var key = string.Empty;
        for (var i = 0; i < 4; i++)
        {
            key += SafeRandomizer.Between(0, 255).ToString("X");
        }

        return key;
    }

    public static int DecodeKey(string key)
    {
        var tTable = key[..(key.Length / 2)];
        var tKey = key[(key.Length / 2)..];
        var checksum = 0;

        for (var i = 0; i < tTable.Length; i++)
        {
            var a = tTable.IndexOf(tKey[i]);

            if (a % 2 == 0)
            {
                a *= 2;
            }

            if (i % 3 == 0)
            {
                a *= 3;
            }

            if (a < 0)
            {
                a = tTable.Length % 2;
            }

            checksum += a;
            checksum ^= a << (i % 3) * 8;
        }
            
        return checksum;
    }
}