using System;

namespace OSBot.Cryptography
{
    public static class XorCrypto
    {
        #region Table
        private const int table_size = 499;
        private static readonly byte[] XorTable = new byte[]
        {
            0x07, 0x59, 0x69, 0x4A, 0x94, 0x11, 0x94, 0x85, 0x8C, 0x88, 0x05, 0xCB, 0xA0, 0x9E, 0xCD, 0x58,
            0x3A, 0x36, 0x5B, 0x1A, 0x6A, 0x16, 0xFE, 0xBD, 0xDF, 0x94, 0x02, 0xF8, 0x21, 0x96, 0xC8, 0xE9,
            0x9E, 0xF7, 0xBF, 0xBD, 0xCF, 0xCD, 0xB2, 0x7A, 0x00, 0x9F, 0x40, 0x22, 0xFC, 0x11, 0xF9, 0x0C,
            0x2E, 0x12, 0xFB, 0xA7, 0x74, 0x0A, 0x7D, 0x78, 0x40, 0x1E, 0x2C, 0xA0, 0x2D, 0x06, 0xCB, 0xA8,
            0xB9, 0x7E, 0xEF, 0xDE, 0x49, 0xEA, 0x4E, 0x13, 0x16, 0x16, 0x80, 0xF4, 0x3D, 0xC2, 0x9A, 0xD4,
            0x86, 0xD7, 0x94, 0x24, 0x17, 0xF4, 0xD6, 0x65, 0xBD, 0x3F, 0xDB, 0xE4, 0xE1, 0x0F, 0x50, 0xF6,
            0xEC, 0x7A, 0x9A, 0x0C, 0x27, 0x3D, 0x24, 0x66, 0xD3, 0x22, 0x68, 0x9C, 0x9A, 0x52, 0x0B, 0xE0,
            0xF9, 0xA5, 0x0B, 0x25, 0xDA, 0x80, 0x49, 0x0D, 0xFD, 0x3E, 0x77, 0xD1, 0x56, 0xA8, 0xB7, 0xF4,
            0x0F, 0x9B, 0xE8, 0x0F, 0x52, 0x47, 0xF5, 0x6F, 0x83, 0x20, 0x22, 0xDB, 0x0F, 0x0B, 0xB1, 0x43,
            0x85, 0xC1, 0xCB, 0xA4, 0x0B, 0x02, 0x19, 0xDF, 0xF0, 0x8B, 0xEC, 0xDB, 0x6C, 0x6D, 0x66, 0xAD,
            0x45, 0xBE, 0x89, 0x14, 0x7E, 0x2F, 0x89, 0x10, 0xB8, 0x93, 0x60, 0xD8, 0x60, 0xDE, 0xF6, 0xFE,
            0x6E, 0x9B, 0xCA, 0x06, 0xC1, 0x75, 0x95, 0x33, 0xCF, 0xC0, 0xB2, 0xE0, 0xCC, 0xA5, 0xCE, 0x12,
            0xF6, 0xE5, 0xB5, 0xB4, 0x26, 0xC5, 0xB2, 0x18, 0x4F, 0x2A, 0x5D, 0x26, 0x1B, 0x65, 0x4D, 0xF5,
            0x45, 0xC9, 0x84, 0x14, 0xDC, 0x7C, 0x12, 0x4B, 0x18, 0x9C, 0xC7, 0x24, 0xE7, 0x3C, 0x64, 0xFF,
            0xD6, 0x3A, 0x2C, 0xEE, 0x8C, 0x81, 0x49, 0x39, 0x6C, 0xB7, 0xDC, 0xBD, 0x94, 0xE2, 0x32, 0xF7,
            0xDD, 0x0A, 0xFC, 0x02, 0x01, 0x64, 0xEC, 0x4C, 0x94, 0x0A, 0xB1, 0x56, 0xF5, 0xC9, 0xA9, 0x34,
            0xDE, 0x0F, 0x38, 0x27, 0xBC, 0x81, 0x30, 0x0F, 0x7B, 0x38, 0x25, 0xFE, 0xE8, 0x3E, 0x29, 0xBA,
            0x55, 0x43, 0xBF, 0x6B, 0x9F, 0x1F, 0x8A, 0x49, 0x52, 0x18, 0x7F, 0x8A, 0xF8, 0x88, 0x24, 0x5C,
            0x4F, 0xE1, 0xA8, 0x30, 0x87, 0x8E, 0x50, 0x1F, 0x2F, 0xD1, 0x0C, 0xB4, 0xFD, 0x0A, 0xBC, 0xDC,
            0x12, 0x85, 0xE2, 0x52, 0xEE, 0x4A, 0x58, 0x38, 0xAB, 0xFF, 0xC6, 0x3D, 0xB9, 0x60, 0x64, 0x0A,
            0xB4, 0x50, 0xD5, 0x40, 0x89, 0x17, 0x9A, 0xD5, 0x85, 0xCF, 0xEC, 0x0D, 0x7E, 0x81, 0x7F, 0xE3,
            0xC3, 0x04, 0x01, 0x22, 0xEC, 0x27, 0xCC, 0xFA, 0x3E, 0x21, 0xA6, 0x54, 0xC8, 0xDE, 0x00, 0xB6,
            0xDF, 0x27, 0x9F, 0xF6, 0x25, 0x34, 0x07, 0x85, 0xBF, 0xA7, 0xA5, 0xA5, 0xE0, 0x83, 0x0C, 0x3D,
            0x5D, 0x20, 0x40, 0xAF, 0x60, 0xA3, 0x64, 0x56, 0xF3, 0x05, 0xC4, 0x1C, 0x7D, 0x37, 0x98, 0xC3,
            0xE8, 0x5A, 0x6E, 0x58, 0x85, 0xA4, 0x9A, 0x6B, 0x6A, 0xF4, 0xA3, 0x7B, 0x61, 0x9B, 0x09, 0x40,
            0x1E, 0x60, 0x4B, 0x32, 0xD9, 0x51, 0xA4, 0xFE, 0xF9, 0x5D, 0x4E, 0x4A, 0xFB, 0x4A, 0xD4, 0x7C,
            0x33, 0x02, 0x33, 0xD5, 0x9D, 0xCE, 0x5B, 0xAA, 0x5A, 0x7C, 0xD8, 0xF8, 0x05, 0xFA, 0x1F, 0x2B,
            0x8C, 0x72, 0x57, 0x50, 0xAE, 0x6C, 0x19, 0x89, 0xCA, 0x01, 0xFC, 0xFC, 0x29, 0x9B, 0x61, 0x12,
            0x68, 0x63, 0x65, 0x46, 0x26, 0xC4, 0x5B, 0x50, 0xAA, 0x2B, 0xBE, 0xEF, 0x9A, 0x79, 0x02, 0x23,
            0x75, 0x2C, 0x20, 0x13, 0xFD, 0xD9, 0x5A, 0x76, 0x23, 0xF1, 0x0B, 0xB5, 0xB8, 0x59, 0xF9, 0x9F,
            0x7A, 0xE6, 0x06, 0xE9, 0xA5, 0x3A, 0xB4, 0x50, 0xBF, 0x16, 0x58, 0x98, 0xB3, 0x9A, 0x6E, 0x36,
            0xEE, 0x8D, 0xEB
        };
        #endregion
        
        public static void Crypt(ref ushort XorPosition, ref byte[] Buffer, int Offset, int Len)
        {
            for (int i = 0; i < Len; i++)
            {
                //encrypt byte
                Buffer[Offset + i] ^= XorTable[XorPosition];
                
                //increase xorpos
                XorPosition++;
                if (XorPosition >= table_size)
                    XorPosition = 0;
            }
        }
    }
}