Python jwt token

Helena 175 Published: 06/22/2024

Python jwt token

Here's a comprehensive guide on using Python to generate and verify JSON Web Tokens (JWTs):

What is JWT?

JSON Web Token (JWT) is a compact, URL-safe means of representing claims to be transferred between two parties. The tokens are digitally signed and can be verified by the recipient. JWTs have become popular for authentication and authorization purposes due to their simplicity and flexibility.

How to Generate JWT with Python using Pyjwt library?

To generate a JWT token in Python, you'll need the pyjwt library. Here's an example of how to use it:

Install pyjwt: 
   pip install pyjwt
Import pyjwt and create a dictionary containing your claims (e.g., username, email): 
   import jwt

payload = {


"user": "username",


"email": "[email protected]"


}
Create an RSA key pair or use a public one: 
   private_key = """-----BEGIN RSA PRIVATE KEY-----

MIICXAIBAAKBgQCf3o6+Yn3T+GxWm5KXw2e0LzBkF1NcY9ZJ8o9A=


-----END RSA PRIVATE KEY-----"""


public_key = """-----BEGIN PUBLIC KEY-----


MFkwEwYHKoZIhvcNAwQEQgCgAEAAp5jG3Hn8sFzUeKmD6Y8i


-----END PUBLIC KEY-----"""
Create a JWT token using the payload and public key: 
   token = jwt.encode(payload=payload, key=public_key.encode(), algorithm="RS256")

Verify a JWT Token with Python

Import pyjwt again and the public key: 
   import jwt

public_key = """-----BEGIN PUBLIC KEY-----


MFkwEwYHKoZIhvcNAwQEQgCgAEAAp5jG3Hn8sFzUeKmD6Y8i


-----END PUBLIC KEY-----"""
Verify the JWT token using the payload and public key: 
   try:

decoded = jwt.decode(token, key=public_key.encode(), algorithms=["RS256"], max_age_seconds=3600)


except jwt.ExpiredSignatureError as e:


print(f"Token has expired: {e}")


except jwt.InvalidTokenError as e:


print(f"Invalid token: {e}")
If the verification is successful, you can access the decoded payload: 
   if 'user' in decoded and 'email' in decoded:

username = decoded['user']


email = decoded['email']


else:


print("Decoded Payload Missing")

Conclusion

In this guide, we've covered how to generate a JSON Web Token (JWT) using Python with the pyjwt library. Additionally, we explored how to verify a JWT token in Python using the same library. This knowledge can be used for authentication and authorization purposes in your web applications.

Python jwt decode

I'd be happy to help you with that! Python's JWT (JSON Web Token) decoding is a straightforward process. Let me walk you through it.

What is JSON Web Token (JWT)?

A JSON Web Token is a compact, URL-safe means of representing claims to be transferred between two parties. The token is digitally signed and contains the issuer's identity and the payload. It's commonly used for authentication and authorization purposes in web applications.

Python JWT Decoding: A Step-by-Step Guide

To decode a JSON Web Token in Python using PyJWT library, you'll need to follow these steps:

Install PyJWT Library: First, install the required library by running pip install pyjwt in your terminal. Import the Required Modules: In your Python script, import the necessary modules: import jwt and from datetime import datetime. Load the JWT Token: Load the JSON Web Token as a string from a file, database, or any other storage medium.

Here's an example of how to load the token:

with open('jwt_token.txt', 'r') as f:

token = f.read()
Decode the JWT Token: Use the jwt.decode() method to decode the token and extract its payload. 
decoded_payload = jwt.decode(token, key='your_secret_key', algorithms=['HS256'])

print(decoded_payload)

In this example:

token is the JSON Web Token string. key is your secret key used for decryption (keep it safe!). algorithms specifies the algorithm used to sign the token. In this case, it's HS256 (HMAC SHA256).

The decoded payload will contain the original data that was encoded in the JWT. This might include user information, roles, permissions, or any other relevant details.

Error Handling

When decoding a JSON Web Token, you should always handle potential errors:

Invalid token: If the token is malformed or tampered with, the jwt.decode() method will raise an error. Expired token: Check if the token has expired by verifying its timestamp. If it's invalid, reject the request.

Here's an example of how to handle errors:

try:

decoded_payload = jwt.decode(token, key='your_secret_key', algorithms=['HS256'])


except jwt.ExpiredSignatureError as e:


print(f"Token {token} is expired: {e}")


except jwt.InvalidTokenError as e:


print(f"Invalid token: {e}")


if not decoded_payload:

Handle the case where the token is invalid or has expired

print("Authentication failed!")

Conclusion

In this guide, we've covered the basics of JSON Web Token decoding in Python using PyJWT. By following these steps and handling potential errors, you'll be able to securely verify and extract information from JWT tokens in your web application.

Remember to keep your secret key safe and secure!

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