This Python package provides a Flask decorator which adds local and remote OAuth2 (RFC-6749) validation for self-encoded JWT (RFC-7519) based Bearer (RFC-6750) access tokens.

It only covers validation logic required by resource servers (APIs) and does not provide any implementation of OAuth2 flows (e.g. authorization code flow).

• The authorization server has to support Authorization Server Metadata (RFC-8414).
• The JWT access tokens should follow the JSON Web Token (JWT) Profile for OAuth 2.0 Access Tokens (RFC-9068).

The minimal configuration expects the OAUTH2_ISSUER attribute being set which points to the issuer:

app.config['OAUTH2_ISSUER'] = 'https://<your-issuer>/oauth2'

This would perform local token validation after downloading the public keys (RFC-7517) from the authorization server (RFC-7800).

In case you also need to perform remote token validation (RFC-7662) an OAUTH2_CLIENT_ID and OAUTH2_CLIENT_SECRET need to be configured:

app.config['OAUTH2_CLIENT_ID'] = 'your-client-id'
app.config['OAUTH2_CLIENT_SECRET'] = 'your-client-secret'

In case your authorization server uses rotating public keys an OAUTH2_JWKS_UPDATE_INTERVAL (in seconds) could be configured to regularly download the latest public keys from the authorization server:

app.config['OAUTH2_JWKS_UPDATE_INTERVAL'] = 3600

For a more strict validation it is recommended to configure an OAUTH2_AUDIENCE to verify the token against:

app.config['OAUTH2_AUDIENCE'] = 'api://default'

To provide OAuth2 token validation to your endpoints simply add the OAuth2Decorator:

from flask_oauth2_validation import OAuth2Decorator

oauth2 = OAuth2Decorator(app)

@oauth2.requires_token()
@app.route('/protected')
def protected():
    pass

This would perform local token validation, only. To enable remote token validation you need to provide the introspect=True argument:

@oauth2.requires_token(introspect=True)
@app.route('/protected')
def protected():
    pass

In case you require one or multiple scopes to allow execution, add the scopes=[...] argument:

@oauth2.requires_token(scopes=['profile', 'email'])
@app.route('/protected')
def protected():
    pass

To use the token from within your method you can access it via the OAuth2Decorator object like:

@oauth2.requires_token()
@app.route('/protected')
def protected():
    token: dict = oauth2.token
    pass

MIT License

Copyright (c) 2021 Henrik Sachse

Permission is hereby granted, free of charge, to any person obtaining a copy
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