Generate RSA private and public key in Python on memory for JWT tokens

jwt_generator.py

from datetime import datetime, timedelta, timezone

from jose import jwt  # or import jwt
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.backends import default_backend


#  --- Generate private and public key ---
key = rsa.generate_private_key(
    backend=default_backend(),
    public_exponent=65537,
    key_size=2048
)

private_key = key.private_bytes(
    encoding=serialization.Encoding.PEM,
    format=serialization.PrivateFormat.PKCS8,
    encryption_algorithm=serialization.NoEncryption()
).decode()

public_key = key.public_key().public_bytes(
    encoding=serialization.Encoding.PEM,
    format=serialization.PublicFormat.SubjectPublicKeyInfo
).decode()

# --- Generate encoded JWT token ---

claims = {
    "sub": "Subject of the payload",
    "exp": datetime.now(tz=timezone.utc) + timedelta(hours=1)  # expire in 1 hour, f.e.
}
encoded = jwt.encode(
    claims=claims,
    algorithm="RS256",
    key=private_key
)

# --- Verify token ---

decoded = jwt.decode(
      token=encoded, key=public_key, algorithms="RS256"
)

# Enjoy! :)

I use it in Pytest fixtures and is useful 👍