Four: How to pretend to "client" to "server" to send us the package we need? Here we need to use a tool, which is between the client and the server side, and its work is to receive and forward the packet, which we call it a proxy. If the agent's work is simple to receive and forward, this is meaningless, but please note: All packets must be transmitted through it, and the meaning here is significant. We can analyze the received packets or forward them directly, or modify forward, or press the packets we need to send. Below we continue how to cheat the server and client at the same time, that is, modify the package and forgery packages. Through our previous analysis, we already know how to play multiple NPC package formats, then we will do it! First we have to find the package sent by the client, find the feature of the battle, is the first package of the request battle, we find "F4 44 1F 30" character, this is not changed, of course, it is necessary to decrypt. After found, it means that the client will ask the server to ask the server, we don't move this package, forward. Continue to find down, then the signature that needs to be found is not good, let's find "Da" first, this is the directive of the client to send NPC information, then there may be "Da", there is no relationship, we look The first three bytes do not have "F4 44". After finding it, our work begins! We determine the NPC number to be hit. This quantity is not very big. The reason is that the package length of the net gold is indicated by a byte. Then a package can have 255 bytes, we have analyzed it, adding an NPC to add 10 bytes, so everyone is counted. It is appropriate to play 20 NPCs. Then we have to calculate the original NPC code analysis of the client, because the added NPC code should add 100000. Calculate our increased NPC code, and combine into a new package, pay attention to the byte representing the length of the package to modify, then forward to the server, this step should pay attention to the algorithm when writing the program, do not cause a large delay. Above we deceive the server ended, the deception of the client is simple. After sending the above package, we will send it to the client according to the new NPC code construction package. The format is "F4 44 12 E9 NPC code 02 00 00 00 00 00 00 00 00", putting each new NPC Constructing such a package, sequentially send it together to the client in order, the client is also deceived, very simple. In the future, there will be other things in the battle, we will not be able to open it.
