P2P Micropaymet System

Compiled by L.C.

This project is attempting to build a command line interface supporting P2P micropay.

How to run the program

First, you need to run makefile by

make

Run client program by

./client

Run server program by

./server

The program runs under the environment of Ubuntu 18.04. with g++ installed.

System structure

There are two programs, server.cpp, srv.h/srv.cpp to support the server function.

server.cpp served as the backbone for server function.
srv.cpp/.h are all the specific handling functions' definition and implementation.

Here are some helper functions and data structures.

void SendMsg(int& sock,const char* msg);
void ReadMsg(int& sock, char* msg, bool print);
void *client(thread_arg* arg);

Send and Read message is used for sending and receiving message from socket.
The client function is used to handle the incoming connection.

Now, we will dive into srv implementation.

struct User{
    string Name = "", Ip = "", Port = "";
    int balance = 10000;
    bool isOnline;
};

class Server {
    private:
        map<string, User*> Users;
    public:
        status RegisterClient(string name);
        status GoOnline(string name, string port, string ip);
        status GoOffline(string name);
        void GetClientList(string name, stringstream &out);
};

Using map as storing structure is to speed up the time needed for searching, inserting, and deletion.
RegisterClient will register clients into the Users map data structure. Before registering the client name, it will first lookup the existence in Users. If it exists, it will return a register fail status message to client.
GoOnline takes the client's name, incoming IP, and port. Update the state of user having name. If it doesn't exist, it will return an 210 fail to client.
GoOffline, it will search for the clients name, and make isOnline=false.
GetClientList, searches for user name and output the string to stringstream out. This out variable is then converted to character array and sent.

Reference for generating the RSA key pair. https://stackoverflow.com/questions/5927164/how-to-generate-rsa-private-key-using-openssl

Encrypt, decrypt http://hayageek.com/rsa-encryption-decryption-openssl-c/

lewiechiu/P2PMicropay

P2P Micropaymet System

Compiled by L.C.

How to run the program

System structure