oauth2.py

from authlib.integrations.flask_oauth2 import (
    AuthorizationServer,
    ResourceProtector,
)
from authlib.integrations.sqla_oauth2 import (
    create_query_client_func,
    create_save_token_func,
    create_revocation_endpoint,
    create_bearer_token_validator,
)
from authlib.oauth2.rfc6749 import grants, OAuth2Request
from authlib.oauth2.rfc7636 import CodeChallenge
from models import db, User
from models import OAuth2Client, OAuth2AuthorizationCode, OAuth2Token
import vuln_protection_config

class AuthorizationCodeGrant(grants.AuthorizationCodeGrant):
    TOKEN_ENDPOINT_AUTH_METHODS = [
        'client_secret_basic',
        'client_secret_post',
        'none',
    ]

    def save_authorization_code(self, code, request):
        auth_code = OAuth2AuthorizationCode(
            code=code,
            client_id=request.client.client_id,
            redirect_uri=request.redirect_uri,
            scope=request.scope,
            user_id=request.user.id,
        )
        db.session.add(auth_code)
        db.session.commit()
        return auth_code

    def query_authorization_code(self, code, client):
        auth_code = OAuth2AuthorizationCode.query.filter_by(
            code=code, client_id=client.client_id).first()
        if auth_code and not auth_code.is_expired():
            return auth_code

    def delete_authorization_code(self, authorization_code):
        db.session.delete(authorization_code)
        db.session.commit()

    def authenticate_user(self, authorization_code):
        return User.query.get(authorization_code.user_id)

    # This overriding is to enable URI Redirect atacks
    @staticmethod
    def validate_authorization_redirect_uri(request: OAuth2Request, client):
        if not vuln_protection_config.REDIRECT_URI:
            return request.redirect_uri
        return super(AuthorizationCodeGrant,AuthorizationCodeGrant).validate_authorization_redirect_uri(request, client)


query_client = create_query_client_func(db.session, OAuth2Client)
save_token = create_save_token_func(db.session, OAuth2Token)
authorization = AuthorizationServer(
    query_client=query_client,
    save_token=save_token,
)
require_oauth = ResourceProtector()


def config_oauth(app):
    authorization.init_app(app)

    # support all grants
    authorization.register_grant(AuthorizationCodeGrant)

    # support revocation
    revocation_cls = create_revocation_endpoint(db.session, OAuth2Token)
    authorization.register_endpoint(revocation_cls)

    # protect resource
    bearer_cls = create_bearer_token_validator(db.session, OAuth2Token)
    require_oauth.register_token_validator(bearer_cls())