void midcrypt(unsigned char key[6], unsigned char in[16], unsigned char out[16]) {
    for (int i = 0; i < 16; ++i) {
        out[i] = in[i];
    }
    for (int k = 0; k < 6; ++k) {
        unsigned char x = key[k];
        for (int r = 0; r < 100; ++r) {
            for (int i = 0; i < 16; ++i) {
                x = x * 5 + 1;
				::global_x[k] =x;
                out[i] ^= x;
                out[i] = sbox[out[i]];
            }
            int first = out[0];
            for (int i = 0; i < 15; ++i) {
                out[i] = (out[i] << 3) ^ (out[i+1] >> 5);
            }
            out[15] = (out[15] << 3) ^ (first >> 5);
        }
    }
}

void decrypt (unsigned char key[6], unsigned char crypted[16], unsigned char decr[16]) {
	for (int i = 0; i < 16; i++) {
		decr[i] = crypted[i];
	}
	for (int k = 5; k >= 0; k--) {
		unsigned char x = ::global_x[k];
		for (int r = 0; r < 100; r++) {
			int first = decr[15];
			int i;
			for (i = 15; i > 0; i--) {
				decr[i] = (((decr[i]) >> 3) ^ (decr[i-1] << 5));
			}
			decr[0] = ((decr[0] >> 3) ^ (first << 5 )) ;
			for (int i = 0; i < 16; i++) {
				unsigned int j;
				for (j = 0; j < sizeof(sbox); j++) {
					if (decr[i] == sbox[j])
						break;
				}
				decr[i] = j;
				decr[i] ^= x;
				x = ((x - 1) * 205) % 256;
			}
		}
	}
}