jwt authentication python flask

To implement JWT authentication in a Flask application using Python, you can follow these steps:

  1. Import the required modules:
from flask import Flask, request
from flask_jwt_extended import JWTManager, jwt_required, create_access_token
  • Here, we import the Flask module for creating the application and handling HTTP requests.

  • We also import the JWTManager module from the flask_jwt_extended package, which provides JWT authentication functionality.

  • Create the Flask application:

app = Flask(__name__)

  • This creates a Flask application object.

  • Configure the JWT secret key:

app.config['JWT_SECRET_KEY'] = 'your-secret-key'

  • The JWT secret key is used to encrypt and decrypt the JWT tokens. Replace 'your-secret-key' with your own secret key.

  • Initialize the JWTManager:

jwt = JWTManager(app)

  • This initializes the JWTManager with the Flask application object.

  • Define a route for user login:

@app.route('/login', methods=['POST'])
def login():
    username = request.json.get('username', None)
    password = request.json.get('password', None)

    # Validate the username and password (you can use your own logic here)
    if username != 'admin' or password != 'password':
        return {'message': 'Invalid credentials'}, 401

    # Generate an access token
    access_token = create_access_token(identity=username)

    # Return the access token
    return {'access_token': access_token}, 200
  • This route handles the user login functionality.
  • It expects a POST request with a JSON payload containing the username and password.
  • You can add your own validation logic for the username and password.
  • If the credentials are valid, it generates an access token using the create_access_token function from the flask_jwt_extended module.

  • The access token is returned as a JSON response.

  • Protect a route with JWT authentication:

@app.route('/protected', methods=['GET'])
@jwt_required()
def protected():
    # Access token is valid, perform protected actions
    return {'message': 'This is a protected route'}, 200
  • This route is protected with JWT authentication using the @jwt_required() decorator.

  • Only requests that include a valid access token in the Authorization header will be allowed to access this route.

  • Run the application:

if __name__ == '__main__':
    app.run()
  • This runs the Flask application.

Make sure to install the necessary dependencies by running pip install Flask flask_jwt_extended.

These steps outline how to implement JWT authentication in a Flask application using Python. By following these steps, you can add secure authentication to your application by leveraging JWT tokens.