JohnServerAPI 0.0.1

This is a module to interact with Server and Client

Socket and SSL

Create crt and key files for server and client

Here are the steps to create a self-signed SSL/TLS certificate and private key for a server:

Generate a private key for the server:

openssl genrsa -out server.key 2048

Generate a certificate signing request (CSR) for the server:

openssl req -new -key server.key -out server.csr

Generate a self-signed SSL/TLS certificate for the server:

openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt

Here are the steps to create a self-signed SSL/TLS certificate and private key for a client: Generate a private key for the client:

openssl genrsa -out client.key 2048

Generate a certificate signing request (CSR) for the client:

openssl req -new -key client.key -out client.csr

Generate a self-signed SSL/TLS certificate for the client:

openssl x509 -req -days 365 -in client.csr -signkey client.key -out client.crt```


## share certificate files between the server and client
Sure, here are the codes for each step:

Create a new file called chain.pem and open it in a text editor:

with open('chain.pem', 'w') as f: pass ``` Copy the contents of the client's SSL/TLS certificate (client.crt) into the chain.pem file:

with open('client.crt', 'r') as client_cert_file, open('chain.pem', 'a') as chain_file:
    client_cert_contents = client_cert_file.read()
    chain_file.write(client_cert_contents)

Copy the contents of the server's SSL/TLS certificate (server.crt) into the chain.pem file, below the client's certificate:

with open('server.crt', 'r') as server_cert_file, open('chain.pem', 'a') as chain_file:
    server_cert_contents = server_cert_file.read()
    chain_file.write(server_cert_contents)

Save and close the chain.pem file:

Note that you can combine steps 2 and 3 into a single block of code, like this:

with open('client.crt', 'r') as client_cert_file, open('server.crt', 'r') as server_cert_file, open('chain.pem', 'w') as chain_file:
    client_cert_contents = client_cert_file.read()
    server_cert_contents = server_cert_file.read()
    chain_file.write(client_cert_contents + server_cert_contents)

This code block opens both the client.crt and server.crt files, reads their contents, and writes them to the chain.pem file.

codes for server and client

For Server:

import ssl

# Create an SSL context and load the server's certificate and private key
ssl_context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
ssl_context.load_cert_chain(certfile='server.crt', keyfile='server.key')

# Load the certificate chain file
ssl_context.load_verify_locations(cafile='chain.pem')

For Client

import ssl

# Create an SSL context and load the client's certificate and private key
ssl_context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
ssl_context.load_cert_chain(certfile='client.crt', keyfile='client.key')

# Load the CA file as a trusted root CA
ssl_context.load_verify_locations(cafile='ca.crt')

# Create a socket and connect to the server
ssl_sock = ssl_context.wrap_socket(socket.socket(socket.AF_INET, socket.SOCK_STREAM))
ssl_sock.connect((HOST, PORT))

# Perform the SSL/TLS handshake and send data
ssl_sock.sendall(b'Hello, server!')
data = ssl_sock.recv(1024)

# Close the SSL/TLS connection
ssl_sock.close()