Flask_PyJWT

Flast_PyJWT is a flask extension for adding authentication and authorization via JWT tokens. Routes can be decorated to require JWT auth or refresh tokens, and can require the presence of additional claims and their values.

Installation

Flask_PyJWT is availabe on PyPi and can be installed with pip:

pip install Flask_PyJWT

or with poetry:

poetry add Flask_PyJWT

A python version of ^3.8 is required.

Flask_PyJWT v1.x supports Flask versions ^2. If you are using Flask version ~=1.1, please use Flask PyJWT v0.x instead.

Documentation

Documentation is hosted by Read the Docs.

You can find documentation for Flask_PyJWT at https://flask-pyjwt.readthedocs.io/

Configuration

Flask_PyJWT's configuration variables are read from the Flask app's config and start with the prefix "JWT_".

Required Values

JWT_ISSUER

(str): The issuer of JWTs. Usually your website/API's name.

JWT_AUTHTYPE

(str): The type of auth to use for your JWTs (HMACSHA256, HMACSHA512, RSA256, RSA512).

Accepted Values:

• HS256
• HS512
• RS256
• RS512

JWT_SECRET

(str | bytes): The secret key or RSA private key to sign JWTs with.

If the JWT_AUTHTYPE is HS256 or HS512, a str is required. if the JWT_AUTHTYPE is RS256 or RS512, a bytes encoded RSA private key is required.

Optional Values

JWT_AUTHMAXAGE

(int): The maximum time, in seconds, that an auth JWT is considered valid.

JWT_REFRESHMAXAGE

(int): The maximum time, in seconds, that a refresh JWT is considered valid.

JWT_PUBLICKEY

(str | bytes): The RSA public key used to verify JWTs with, if the JWT_AUTHTYPE is set to RS256 or RS512.

Example Usage

from Flask import flask, request
from Flask_PyJWT import auth_manager, current_token, require_token

app = Flask(__name__)
app.config["JWT_ISSUER"] = "Flask_PyJWT" # Issuer of tokens
app.config["JWT_AUTHTYPE"] = "HS256" # HS256, HS512, RS256, or RS512
app.config["JWT_SECRET"] = "SECRETKEY" # string for HS256/HS512, bytes (RSA Private Key) for RS256/RS512
app.config["JWT_AUTHMAXAGE"] = 3600
app.config["JWT_REFRESHMAXAGE"] = 604800

auth_manager = AuthManager(app)

# Create auth and refresh tokens with the auth_manager object
@app.route("/login", METHODS=["POST"])
def post_token():
    username = request.form["username"]
    password = request.form["password"]
    # Some user authentication via username/password
    if not valid_login(username, password):
        return {"error": "Invalid login credentials"}, 401
    # Retrieve some authorizations the user has, such as {"admin": True}
    authorizations = get_user_authorizations(username)
    # Create the auth and refresh tokens
    auth_token = auth_manager.auth_token(username, authorizations)
    refresh_token = auth_manager.refresh_token(username)
    return {
        "auth_token": auth_token.signed,
        "refresh_token": refresh_token.signed
    }, 200

# Protect routes by requiring auth tokens
@app.route("/protected_route")
@require_token()
def protected_route():
    return {"message": "You've reached the protected route!"}, 200

# Provision new auth tokens by requiring refresh tokens
@app.route("/refresh", method=["POST"])
@require_token("refresh")
def refresh_token_route():
    username = current_token.sub
    # Retrieve some authorizations the user has, such as {"admin": True}
    authorizations = get_user_authorizations(username)
    new_auth_token = auth_manager.auth_token(username, authorizations)
    return {
        "auth_token": new_auth_token.signed
    }, 200

# Require specific claims in auth or refresh tokens
# to match a route's rule variables
@app.route("/user_specific_route/<string:username>")
@require_token(sub="username")
def user_specific_route(username):
    return {"message": f"Hello, {username}!"}, 200

# Require arbitrary claims in auth or refresh tokens
@app.route("/custom_claim_route")
@require_token(custom_claim="Arbitrary Required Value")
def custom_claim_route():
    return {"message": "You've reached the custom claim route!"}, 200

# Require authorizations to be present in an auth token's scope
@app.route("/admin_dashboard")
@require_token(scope={"admin": True})
def admin_dashboard():
    return {"message": f"Hello admin!"}

# Access the current token's information using current_token
@app.route("/token/info")
@require_token()
def extract_token_info():
    return {
        "token_type": current_token.token_type,
        "subject": current_token.sub,
        "scope": current_token.scope,
        "claims": current_token.claims,
        "is_signed": current_token.is_signed()
        "signed_token": current_token.signed,
    }

# Require authorization to be present in an auth token's scope or claims, but
# with the option to override those values with other claims
@app.route("/overridable_route/<string:username>")
@require_token(sub="username", override={"admin": True})
def overridable_route():
    is_admin = current_token.claims.get("admin")
    return {"message": f"Hello, {'admin' if is_admin else username}!"}, 200