buf.writeByte(RdpConstants.RDP_NEG_REQ_TYPE_NEG_REQ);
// RDP_NEG_REQ::flags (0)
buf.writeByte(RdpConstants.RDP_NEG_REQ_FLAGS);
// RDP_NEG_REQ::length (constant: 8) short int in LE format
buf.writeByte(0x08);
buf.writeByte(0x00);
// RDP_NEG_REQ: Requested protocols: PROTOCOL_SSL
buf.writeIntLE(protocol);
// Calculate length of packet and prepend it to buffer