NETWORK

Working on a custom implementation of FTP server

Current implementation

Just a basic challenge security auth using openssl and some back and forth signal receiving in a traditional CS arch

-> Allows for one file download from server (directory is hardcoded atm)

SSL security

We are using openssl for a more safer socket connection and transmission

To generate server key and certificate: (RUN IN YOUR SERVER(PC) AND SEND IT TO YOUR PHONE)

# Give the Common name as your server's IP addr, email is not necessary
openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout server_key.pem -out server_cert.pem

Make sure that the following files are sent over to your phone using this command:

# You will have to also send over the servers' certificate:- server_cert.pem file to your phone
mkdir inLimbo_client
cd inLimbo_client/
curl -L -o client.cpp https://raw.githubusercontent.com/nots1dd/inLimbo/main/src/network/client.cpp
curl -L -o protocols.h https://raw.githubusercontent.com/nots1dd/inLimbo/main/src/network/protocols.h

Note

You will need to have termux installed and configured in order to compile client code in your phone

IOS users sadly cannot use this feature

MAKE SURE THAT YOU SETUP TERMUX IN YOUR PHONE BY RUNNING termux-setup-storage

This is to get access to the Internal Storage of your android phone in termux itself

# To install compiler and compiling client.cpp in your phone (android only)
pkg install clang libllvm
clang++ client.cpp -lcrypto -lssl -o client
./client # make sure you have server_cert.pem in your phone already

CAUTION: If client refuses to connect and you are sure that everything is done as explained,

-> Consider changing the SERVER_IP macro in protocols.h to the server's ip address (you can find it out in linux using ip a)

In code it should look something like this:

#define SERVER_IP "127.0.0.1" // by default it is set to loopback addr, set this to the actual servers ip

I will come up with a more dynamic way of setting this in the future but right now it is pretty rigid.

-> The server will have access to the password hash that you will give in config.toml file

-> The client will input the password and compute the sha256 hash of salt+password and raise a challenge with the server's hash

-> If they match, we autheticate successfully, else it fails

-> Needless to say, the client also needs the server_cert.pem file as well else client can never connect

The above forms a baseline security and safety of your connection with the FTP server, it may not be the most secure nor the ideal process to go about securing a FTP server, but it works.

If it is not obvious enough, the default password is password.

Note

TO CHANGE YOUR PASSWORD:

It is simple enough actually, follow these steps:

1. Change salt if you want to, upon choosing give it in your config.toml file AND your client.cpp code!
2. Get a password of your choosing and concatenate salt and password (salt + password -> in this order)
3. Get its SHA256 hash of the concatenated string (can go to an online alternative) or just use openssl or other binaries to find its hash
4. Put the hash in config.toml under password_hash field
   
   You are all done!
   
   

Currently SALT and USERNAME are hardcoded and tedious to change, but this will change in the future

Goal

The goal of this server is to easily transfer your local songs directory from your PC to phone without a hassle