char cryptdatahead[] = {
magic
0x51,0xc6,0x74,0xc0,
crypted data packet
0x01,0x87,
0x01,0x1c,
unknown
0x01,0x18,
0x00,0x04,
0x00,0x00,0x00,0x00,
unknown
0x01,0x9c,
0x00,0x04,
0x00,0x00,0x00,0x02,
crypted data, size 0x108
0x01,0x88,
0x01,0x08
};

In between here comes the encrypted data. That data is, specifically the random 16 byte key encrypted using the client's public RSA key. Should be encrypted with RSA_PKCS1_PADDING. Don't forget to reverse it after encrypting it.

char cryptdatafoot[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };