from google.appengine.ext.webapp.template import render, register_template_library
from google.appengine.ext import ndb
from google.appengine.api import users, memcache
from googleapiclient.errors import HttpError
from urlparse import urlparse
import logging
import webapp2
import config
import gsuite
from third_party import xsrfutil
register_template_library('third_party.xsrfutil')
class Link(ndb.Model):
url = ndb.StringProperty()
owner_id = ndb.StringProperty()
owner_name = ndb.StringProperty()
viewcount = ndb.IntegerProperty()
public = ndb.BooleanProperty()
visibility = ndb.TextProperty()
def errorPage(response, code, message):
context = {'code': code, 'message': message, 'corpname': config.CORP_NAME}
response.write(render('template/error.html', context))
response.set_status(code)
def check_redirect(func):
def decorate(self, *args, **kwargs):
if config.ALWAYS_REDIRECT_TO_FQDN and self.request.host != config.GOLINKS_FQDN:
url = self.request.url.replace(self.request.host, config.GOLINKS_FQDN, 1)
return self.redirect(url)
return func(self, *args, **kwargs)
return decorate
def isValidUrl(url):
o = urlparse(url)
return o.scheme in config.URL_ALLOWED_SCHEMAS
class ShowLinks(webapp2.RequestHandler):
@check_redirect
def get(self, param):
user = users.get_current_user()
if not user:
self.redirect(users.create_login_url(self.request.path))
return
sign_out_link = users.create_logout_url('/')
is_admin = users.is_current_user_admin()
if param == "all" and is_admin:
links = Link.query().fetch()
else:
links = Link.query(Link.owner_id == user.user_id()).fetch()
context = {
"links": links,
"is_admin": is_admin,
"sign_out_link": sign_out_link,
"fqdn": config.GOLINKS_FQDN,
"hostname": config.GOLINKS_HOSTNAME
}
self.response.write(render("template/list.html", context))
class DeleteLink(webapp2.RequestHandler):
@check_redirect
@xsrfutil.xsrf_protect
def post(self, link):
user = users.get_current_user()
if not user:
self.redirect(users.create_login_url(self.request.path))
return
key = link.rstrip("/")
l = Link.get_by_id(key)
if l.owner_id:
if l.owner_id != user.user_id() and not users.is_current_user_admin():
logging.info("%s tried to delete /%s but doesn't have permission" %
(user.email(), key))
errorPage(self.response, 403, "Access denied")
return
l.key.delete()
logging.info("%s deleted /%s" % (user.email(), key))
self.redirect("/links/my")
class EditLink(webapp2.RequestHandler):
@check_redirect
@xsrfutil.xsrf_protect
def post(self, link):
user = users.get_current_user()
if not user:
self.redirect(users.create_login_url(self.request.path))
return
key = self.request.get("key", "").rstrip("/")
url = self.request.get("url", None)
public = self.request.get("public", 0)
visibility = self.request.get("visibility", "")
if not key:
errorPage(self.response, 400, "Shortened URL required")
return
blacklist = ["edit", "links", "delete"]
for word in blacklist:
if key.startswith(word + '/') or key == word:
logging.info("%s tried to add forbidden URL /%s" % (user.email(), key))
errorPage(self.response, 400, "Shortened URL forbidden")
return
if link:
if key != link:
logging.info(
"%s tried to change /%s to %s but such request is forbidden" %
(user.email(), link, key))
errorPage(self.response, 400, "Cannot change shortened URL")
return
if not isValidUrl(url):
logging.info("%s tried to set /%s to illegal URL: %s" %
(user.email(), key, url))
errorPage(self.response, 400, "URL Illegal")
return
l = Link.get_or_insert(key)
if l.owner_id:
if not link:
logging.info("%s tried to overwrite /%s" % (user.email(), key))
errorPage(
self.response, 500,
"Link already exists... Please update existing one or change url.")
return
if l.owner_id != user.user_id() and not users.is_current_user_admin():
logging.info("%s tried to modify /%s but doesn't have permission" %
(user.email(), key))
errorPage(self.response, 403, "Access denied")
return
else:
l.owner_id = user.user_id()
l.owner_name = user.nickname()
if config.ENABLE_GOOGLE_GROUPS_INTEGRATION:
groups = map(lambda x: x.strip(), visibility.split(';'))
for group in groups:
if group:
try:
logging.info("Checking if %s is a valid group" % group)
gsuite.directory_service.groups().get(groupKey=group).execute()
except HttpError:
logging.info("%s tried to add invalid group %s to /%s" %
(user.email(), group, key))
errorPage(self.response, 400, "Invalid group: " + group)
return
l.visibility = visibility
l.url = url
if public:
l.public = True
else:
l.public = False
if not l.viewcount:
l.viewcount = 0
l.put()
logging.info("%s created or updated /%s to %s" % (user.email(), key, url))
self.redirect("/edit/" + key)
@check_redirect
def get(self, link):
user = users.get_current_user()
if not user:
self.redirect(users.create_login_url(self.request.path))
return
sign_out_link = users.create_logout_url('/')
is_admin = users.is_current_user_admin()
context = {
"sign_out_link": sign_out_link,
"is_admin": is_admin,
"show_visibility": config.ENABLE_GOOGLE_GROUPS_INTEGRATION,
'hostname': config.GOLINKS_HOSTNAME
}
if link:
link = link.rstrip("/")
context.update({'key': link})
l = Link.get_by_id(link)
if l:
if l.owner_id:
if l.owner_id != user.user_id() and not is_admin:
logging.info(
"%s tried to check details page of /%s but doesn't have permission"
% (user.email(), link))
errorPage(self.response, 403, "Access denied")
return
context.update({
'url': l.url,
'viewcount': l.viewcount,
'public': l.public,
'visibility': l.visibility or '',
'can_delete': 1,
'owner': l.owner_name
})
logging.info("%s checked details page of /%s" % (user.email(), link))
self.response.write(render("template/edit.html", context))
class RedirectLink(webapp2.RequestHandler):
@check_redirect
def get(self, link):
user = users.get_current_user()
if link:
link = link.rstrip("/")
l = Link.get_by_id(link)
if l:
if l.public:
username = "public-user"
else:
if not user:
self.redirect(users.create_login_url(self.request.path))
return
username = user.email()
if l.visibility:
if config.ENABLE_GOOGLE_GROUPS_INTEGRATION:
memcacheKey = "v_%s_%s" % (user.user_id(), link)
if not config.USE_MEMCACHE or not memcache.get(memcacheKey):
groups = map(lambda x: x.strip(), l.visibility.split(';'))
no_access = True
for group in groups:
if group:
try:
# NOTES: this does support nested group members but doesn't support external users
# even though we don't currently allow external users to log in, this is worth
# noting if we decide to support
logging.info("Checking if %s is a member of %s" %
(username, group))
if gsuite.directory_service.members().hasMember(
groupKey=group,
memberKey=user.email()).execute()['isMember']:
no_access = False
break
except HttpError:
pass
if no_access:
# no caching for 403 so that user can gain access immediately
logging.info(
"%s tried to access /%s but failed visibilitty check" %
(username, link))
errorPage(self.response, 403,
"You do not have access to the requested resource")
return
if config.USE_MEMCACHE:
memcache.set(memcacheKey, 1, config.MEMCACHE_TTL)
else:
logging.info("%s has access to /%s by cache" % (username, link))
l.viewcount += 1
l.put()
logging.info("%s accessed /%s and redirected to %s" %
(username, link, str(l.url)))
self.redirect(str(l.url))
return
if not user: # we don't want external to know if url exists
self.redirect(users.create_login_url(self.request.path))
return
if not link:
self.redirect('/links/my')
return
logging.info("%s accessed non-existent URL /%s" % (user.email(), link))
errorPage(self.response, 404, "Not Found!")
app = webapp2.WSGIApplication([
('/edit/([-\/\w]*)', EditLink),
('/delete/([-\/\w]+)', DeleteLink),
('/links/(\w*)', ShowLinks),
('/([-\/\w]*)', RedirectLink),
],
debug=True)
