BASIC HTTP AUTHENTICATION

Basic Authentication is a simple HTTP authentication mechanism where a web page or resource requires a username and password to grant access. The credentials are sent in the HTTP headers encoded in Base64.

APACHE (.HTACCESS)

#Create a .htaccess file in the directory to be protected
root@engineering:~$ nano .htaccess
 AuthType Basic
 AuthName "Restricted Area"
 AuthUserFile /path/to/.htpasswd
 Require valid-user

#Create a .htpasswd file to store user credentials
root@ngineering:~$ nano .htpasswd
 htpasswd -c /path/to/.htpasswd username
 
#restart apache server
root@engineering:~$ sudo systemctl restart apache2

#Ensure the .htaccess feature is enabled in Apache by verifying the AllowOverride directive is properly configured in your Apache configuration files (e.g., /etc/apache2/sites-available/000-default.conf).
root@engineering:~$ nano /etc/apache2/sites-available/000-default.conf
 <Directory /var/www/html>
  AllowOverride All
 </Directory>

#Reload Apache after making configuration changes:
root@ngineering:~$ sudo systemctl reload apache2

#
root@engineering:~$ curl -u username:password http://www.example.com/protected-resource

NGINX

#Modify the Nginx Configuration
root@engineering:~$ nano /etc/nginx/sites-available/example.conf
 * ALT: /etc/nginx/nginx.conf
 
 server {
  listen 80;
  server_name example.com;

  location /protected/ {
   auth_basic "Restricted Area";
   auth_basic_user_file /etc/nginx/.htpasswd;
  }

  # Other server configurations...
 }

#Create the .htpasswd File
#The .htpasswd file stores the username and encrypted password for basic authentication
root@engineering:~$ sudo apt update
root@engineering:~$ sudo apt install apache2-utils
root@engineering:~$ nano .htpasswd
root@engineering:~$ sudo htpasswd -c /etc/nginx/.htpasswd username

#to add more users
root@engineering:~$ sudo htpasswd /etc/nginx/.htpasswd newuser

#test nginx configuration
root@engineering:~$ sudo nginx -t
 nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
 nginx: configuration file /etc/nginx/nginx.conf test is successful
root@engineering:~$ sudo systemctl restart nginx

root@engineering:~$ curl -u username:password http://www.example.com/protected-resource

FLASK

root@engineering:~$ 
from flask import Flask, request, Response

app = Flask(__name__)

def check_auth(username, password):
    return username == 'admin' and password == 'password'

def authenticate():
    return Response(
        'Could not verify your access level.\n', 401,
        {'WWW-Authenticate': 'Basic realm="Login Required"'})

@app.route('/protected')
def protected():
    auth = request.authorization
    if not auth or not check_auth(auth.username, auth.password):
        return authenticate()
    return "Hello, you have access!"

if __name__ == '__main__':
    app.run()