internal static byte[] FromHexString(string s)
        {
            if ((s != null) ? ((s.Length % 2) > 0) : true)            
                return null;
            
            List<byte> list = new List<byte>();
            for (int i = 0; i < s.Length; i += 2)
            {
                byte num2;
                if (byte.TryParse(s.Substring(i, 2), NumberStyles.HexNumber, (IFormatProvider)null, out num2))
                {
                    list.Add(num2);
                }
            }
            return list.ToArray();
        }

        internal static bool Validate(string email, string unlockCode)
        {            
            email = email.ToLower();
            byte[] buffer = FromHexString(unlockCode); //将unlockCode转为byte数组
            if ((buffer == null) || (buffer.Length <= 2))
            {
                return false;
            }
            List<byte> source = new List<byte>();
            for (int j = 0; j < (buffer.Length - 2); j++)
            {
                source.Add(buffer[j]); //把unlockCode放入source
            }
            source.AddRange(MD5.Create().ComputeHash(Encoding.ASCII.GetBytes($"{email}@2016"))); //把计算email的哈希放入source
            //然后将source中的行序号与value相乘后全部累加  再与unlockCode比较是否相等
            return (((ushort)(source.Select<byte, int>((t, i) => ((i + 1) * t)).Sum() & 0xffff)) == BitConverter.ToUInt16(buffer, buffer.Length - 2));
        }

[培训]《安卓高级研修班(网课)》月薪三万计划，掌握调试、分析还原ollvm、vmp的方法，定制art虚拟机自动化脱壳的方法