hswaw/lib: add flask_spaceauth

Change-Id: I3bb47bb65e739eaf27f54c07f03df18e79b398e0

hswaw/lib/flask_spaceauth/.gitignore

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+*.py[co]

hswaw/lib/flask_spaceauth/BUILD

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+py_binary(
+    name = "example",
+    srcs = ["example.py"],
+    deps = [
+        "//hswaw/lib/flask_spaceauth/spaceauth",
+        "@pydeps//flask",
+    ]
+)

hswaw/lib/flask_spaceauth/README.md

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+Flask-SpaceAuth
+===============
+
+Simple wrapper around Flask-OAuthlib & Flask-Login for quick and dirty
+integration of random services with [Warsaw Hackerspace Single
+Sign-On](https://sso.hackerspace.pl).

hswaw/lib/flask_spaceauth/example.py

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+from flask import Flask, request, url_for, Markup
+
+from hswaw.lib.flask_spaceauth.spaceauth import SpaceAuth, login_required, \
+    cap_required, current_user
+
+app = Flask('spaceauth-example')
+app.config['SECRET_KEY'] = 'testing'
+app.config['SPACEAUTH_CONSUMER_KEY'] = 'testing'
+app.config['SPACEAUTH_CONSUMER_SECRET'] = 'asdTasdfhwqweryrewegfdsfJIxkGc'
+auth = SpaceAuth(app)
+
+@app.route('/')
+def index():
+    return Markup('Hey! <a href="%s">Login with spaceauth</a> / %r') % (
+            url_for('spaceauth.login'), current_user)
+
+@app.route('/profile')
+@login_required
+def profile():
+    return Markup('Hey {}!').format(spaceauth.current_user)
+
+@app.route('/staff')
+@cap_required('staff')
+def staff_only():
+    return 'This is staff-only zone!'
+
+
+if __name__ == "__main__":
+    app.run()

hswaw/lib/flask_spaceauth/spaceauth/BUILD

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+py_library(
+    name = "spaceauth",
+    srcs = [
+        "__init__.py",
+        "caps.py",
+    ],
+    visibility = ["//visibility:public"],
+    deps = [
+        "@pydeps//blinker",
+        "@pydeps//flask_login",
+        "@pydeps//flask_oauthlib",
+    ],
+)

hswaw/lib/flask_spaceauth/spaceauth/__init__.py

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+from flask import Blueprint, request, url_for, session, redirect, abort, flash
+from flask_oauthlib.client import OAuth, OAuthException
+from flask_login import LoginManager, login_user, logout_user, current_user, login_required, UserMixin
+
+from .caps import cap_required
+
+
+class SpaceAuth(LoginManager):
+    def __init__(self, app=None, *args, **kwargs):
+        self.oauth = OAuth()
+        self.remote = self.oauth.remote_app(
+            'spaceauth',
+            base_url='https://sso.hackerspace.pl/api/',
+            access_token_url='https://sso.hackerspace.pl/oauth/token',
+            authorize_url='https://sso.hackerspace.pl/oauth/authorize',
+            request_token_params={'scope': 'profile:read'},
+            app_key='SPACEAUTH')
+        self.remote.tokengetter(self.tokengetter)
+
+        bp = Blueprint('spaceauth', __name__)
+        bp.add_url_rule('/login', 'login', self.login_view_handler)
+        bp.add_url_rule('/logout', 'logout', self.logout_view_handler)
+        bp.add_url_rule('/callback', 'callback', self.callback_view_handler)
+        self.blueprint = bp
+
+        super(SpaceAuth, self).__init__()
+        self.refresh_view = 'spaceauth.login'
+        self.login_view = 'spaceauth.login'
+        self.user_loader(self.user_loader_handler)
+
+        if app:
+            self.init_app(app, *args, **kwargs)
+
+    def init_app(self, app, url_prefix='/oauth'):
+        self.oauth.init_app(app)
+        super(SpaceAuth, self).init_app(app)
+        app.register_blueprint(self.blueprint, url_prefix=url_prefix)
+
+        @app.errorhandler(OAuthException)
+        def errorhandler(err):
+            flash('OAuth error occured', 'error')
+            return redirect('/')
+
+    def login_view_handler(self):
+        session['spaceauth_next'] = request.args.get('next') or request.referrer
+        return self.remote.authorize(
+            callback=url_for('spaceauth.callback', _external=True)
+            )
+
+    def logout_view_handler(self):
+        # TODO revoke token
+        session.pop('spaceauth_token', None)
+        session.pop('spaceauth_next', None)
+        logout_user()
+        return redirect('/')
+
+    def callback_view_handler(self):
+        resp = self.remote.authorized_response()
+        if resp is None:
+            raise OAuthException(
+                'Access denied', type=request.args.get('error'))
+
+        # TODO encrypt token...?
+        session['spaceauth_token'] = resp['access_token']
+        profile = self.remote.get('profile').data
+
+        login_user(self.user_loader_handler(profile['username'], profile))
+        return redirect(session.pop('spaceauth_next', None) or '/')
+
+    def tokengetter(self):
+        return (session.get('spaceauth_token'), '')
+
+    def user_loader_handler(self, uid, profile=None):
+        """
+        Default user loader just to differentiate authenticated user from
+        anonymous.
+        """
+
+        user = UserMixin()
+        user.id = uid
+        return user
+
+    def user_profile(self):
+        return self.remote.get('profile').data

hswaw/lib/flask_spaceauth/spaceauth/caps.py

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+from flask import abort, session, current_app
+from flask_login import current_user
+from flask_login.signals import user_logged_out
+import requests
+import functools
+import time
+
+
+def cap_check(capability, user=None):
+    '''Checks if specified user (or current user) has desired capacifier
+    capability'''
+    if not user and not current_user.is_authenticated:
+        return False
+
+    user = user or current_user.get_id()
+
+    cache_key = '{}-{}'.format(user, capability)
+    cached_cap = session.get('_caps', {}).get(cache_key, (False, 0))
+
+    if cached_cap[1] > time.time():
+        return cached_cap[0]
+
+    allowed = requests.get(
+        'https://capacifier.hackerspace.pl/%s/%s' % (capability, user)
+        ).status_code == 200
+
+    if '_caps' not in session:
+        session['_caps'] = {}
+
+    session['_caps'][cache_key] = \
+        (allowed, time.time() + current_app.config.get('CAP_TTL', 3600))
+
+    return allowed
+
+
+@user_logged_out.connect
+def caps_cleanup(app, user):
+    # Cleanup caps cache
+    session.pop('_caps', None)
+
+
+def cap_required(capability):
+    '''Decorator to check if user has desired capacifier capability, returns
+    403 otherwise'''
+
+    def inner(func):
+        @functools.wraps(func)
+        def wrapped(*args, **kwargs):
+            if not cap_check(capability):
+                abort(403)
+
+            return func(*args, **kwargs)
+
+        return wrapped
+    return inner