Python jwt example

Python jwt example

I'm happy to help! However, I must remind you that I'll respond in English as per the rules provided earlier. Here's an example of how you can use JWT (JSON Web Token) in Python:

What is JSON Web Token (JWT)?

A JSON Web Token (JWT) is a compact, URL-safe means of representing claims to be transferred between two parties. The token is digitally signed and contains information about the user, such as their username, email address, or role. JWTs are commonly used for authentication and authorization in web applications.

Python JWT Example

Here's an example of how you can use JWT in a Python application using the pyjwt library:

First, install the required libraries:

pip install pyjwt flask

Next, create a Flask app and import the necessary modules:

from flask import Flask, request, jsonify
import jwt
app = Flask(name)
app.config['SECRET_KEY'] = 'my_secret_key'
Define a secret key for signing JWTs
secret_key = 'your_secret_key_here'

Generate a JWT

To generate a JWT, you need to create a payload with the desired claims and sign it with your secret key:

def generate_jwt(username):
Create a payload dictionary
payload = {
'username': username,
'iat': int(time.time()),
'exp': int(time.time()) + 3600  # Expiration time (1 hour from now)
}
Sign the payload with your secret key
token = jwt.encode(payload, secret_key, algorithm='HS256')
return token.decode('utf-8')

Verify a JWT

To verify a JWT, you need to decode it and check if it's valid:

def verify_jwt(token):
try:
Decode the JWT
payload = jwt.decode(token.encode('utf-8'), secret_key, algorithms=['HS256'])
Check if the token is valid
if 'username' in payload and 'iat' in payload and 'exp' in payload:
return True
except Exception as e:
print(f"Error verifying JWT: {str(e)}")
return False

Example Usage

Here's an example of how you can use the generate_jwt and verify_jwt functions:

@app.route('/login', methods=['POST'])
def login():
username = request.form['username']
password = request.form['password']
Generate a JWT for the user
token = generate_jwt(username)
return jsonify({'token': token})
@app.route('/protected', methods=['GET'])
def protected():
if 'Authorization' not in request.headers:
return jsonify({'error': 'Unauthorized'}), 401
token = request.headers['Authorization'].split(' ')[1]
Verify the JWT
if verify_jwt(token):
return jsonify({'message': 'Hello, authenticated user!'})
else:
return jsonify({'error': 'Invalid or expired JWT'}), 403

In this example, we have two routes: /login and /protected. The /login route generates a JWT for the user based on their username and password. The /protected route verifies the JWT using the verify_jwt function and returns a message if it's valid.

Conclusion

This is just a basic example of how you can use JWT in a Python application with Flask. You can customize the payload and verification process to fit your specific needs. Remember to always keep your secret key secure and never share it with anyone!

Python jwt tutorial

I'd be happy to provide a Python JWT (JSON Web Token) tutorial for you!

What is JSON Web Token?

JSON Web Token (JWT) is a compact, URL-safe means of representing claims to be transferred between two parties. The token is digitally signed and contains three main components:

Python JWT Tutorial

We'll use pyjwt and flask libraries for this tutorial. You can install them via pip:

pip install pyjwt flask

Create a secret key using a library like os in Python:

import os
secret_key = os.urandom(32)
print(secret_key.hex())  # Convert to hexadecimal for easier reading

Store this key securely, as it will be used to sign and verify JWT tokens.

Create a new flask app:

from flask import Flask, request, jsonify
app = Flask(name)

Using the pyjwt library, create a function to generate a JWT token. This token will contain user data (e.g., username and ID):

import jwt
import datetime
def generate_jwt_token(username, user_id):
payload = {
'iat': int(datetime.datetime.utcnow().replace(tzinfo=datetime.timezone.utc).timestamp()),
'exp': int((datetime.datetime.utcnow() + datetime.timedelta(minutes=30)).replace(tzinfo=datetime.timezone.utc).timestamp()),
'username': username,
'user_id': user_id
}
token = jwt.encode(payload, secret_key, algorithm='HS256')
return token.decode('utf-8')
Example usage:
username = 'johnDoe'
user_id = 12345
token = generate_jwt_token(username, user_id)
print(token)  # Output: the generated JWT token string

Create a function to verify an incoming JWT token:

def verify_jwt_token(token):
try:
payload = jwt.decode(token.encode('utf-8'), secret_key, algorithms=['HS256'])
return payload
except jwt.ExpiredSignatureError:
return {'error': 'Token has expired'}
except jwt.InvalidTokenError:
return {'error': 'Invalid token'}
Example usage:
incoming_token = 'your_incoming_jwt_token_string'
verified_payload = verify_jwt_token(incoming_token)
if verified_payload['error']:
print(verified_payload['error'])
else:
print("Verified payload: ", verified_payload)

Now, let's secure a Flask route using the verify_jwt_token function:

@app.route('/protected_route', methods=['GET'])
def protected_route():
token = request.headers.get('Authorization')
if not token:
return jsonify({'error': 'Unauthorized'}), 401
payload = verify_jwt_token(token)
if 'error' in payload:
return jsonify(payload), 401
else:
The user is authenticated, you can perform actions here
return jsonify({'message': 'Hello, authenticated user!'})
if name == 'main':
app.run(debug=True)

Conclusion

In this tutorial, we've covered the basics of JSON Web Tokens (JWTs) and how to use them for authentication in a Python Flask application. We created a secret key, generated JWT tokens, and verified incoming tokens using pyjwt. Finally, we secured an API endpoint with JWT authentication.

Remember to keep your secret key secure and never share it publicly!