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私はOAuthのは、Facebookのキャンバスのアプリのためにも推奨されていることを見て、私が持っていたコードは動作しませんでした、それはsigned_requestを使用しようとしたが、すべての時間が私はリロードをしなければならなかったセッションを変更：Facebook Canvasアプリに署名されたリクエストが必要ですか？
class Facebook(object):
"""Wraps the Facebook specific logic"""
def __init__(self, app_id=conf.FACEBOOK_APP_ID,
app_secret=conf.FACEBOOK_APP_SECRET):
self.app_id = app_id
self.app_secret = app_secret
self.user_id = None
self.access_token = None
self.signed_request = {}
def api(self, path, params=None, method=u'GET', domain=u'graph'):
"""Make API calls"""
if not params:
params = {}
params[u'method'] = method
if u'access_token' not in params and self.access_token:
params[u'access_token'] = self.access_token
result = json.loads(urlfetch.fetch(
url=u'https://' + domain + u'.facebook.com' + path,
payload=urllib.urlencode(params),
method=urlfetch.POST,
headers={
u'Content-Type': u'application/x-www-form-urlencoded'})
.content)
if isinstance(result, dict) and u'error' in result:
raise FacebookApiError(result)
return result
def load_signed_request(self, signed_request):
"""Load the user state from a signed_request value"""
try:
sig, payload = signed_request.split(u'.', 1)
sig = self.base64_url_decode(sig)
data = json.loads(self.base64_url_decode(payload))
expected_sig = hmac.new(
self.app_secret, msg=payload, digestmod=hashlib.sha256).digest()
# allow the signed_request to function for upto 1 day
if sig == expected_sig and \
data[u'issued_at'] > (time.time() - 86400):
self.signed_request = data
self.user_id = data.get(u'user_id')
self.access_token = data.get(u'oauth_token')
except ValueError, ex:
pass # ignore if can't split on dot
@property
def user_cookie(self):
"""Generate a signed_request value based on current state"""
if not self.user_id:
return
payload = self.base64_url_encode(json.dumps({
u'user_id': self.user_id,
u'issued_at': str(int(time.time())),
}))
sig = self.base64_url_encode(hmac.new(
self.app_secret, msg=payload, digestmod=hashlib.sha256).digest())
return sig + '.' + payload
@staticmethod
def base64_url_decode(data):
data = data.encode(u'ascii')
data += '=' * (4 - (len(data) % 4))
return base64.urlsafe_b64decode(data)
@staticmethod
def base64_url_encode(data):
return base64.urlsafe_b64encode(data).rstrip('=')
class CsrfException(Exception):
pass
class BaseHandler(webapp.RequestHandler):
facebook = None
user = None
csrf_protect = True
def initialize(self, request, response):
"""General initialization for every request"""
super(BaseHandler, self).initialize(request, response)
try:
self.init_facebook()
self.init_csrf()
self.response.headers[u'P3P'] = u'CP=HONK' # iframe cookies in IE
except Exception, ex:
self.log_exception(ex)
raise
def handle_exception(self, ex, debug_mode):
"""Invoked for unhandled exceptions by webapp"""
self.log_exception(ex)
self.render(u'error',
trace=traceback.format_exc(), debug_mode=debug_mode)
def log_exception(self, ex):
"""Internal logging handler to reduce some App Engine noise in errors"""
msg = ((str(ex) or ex.__class__.__name__) +
u': \n' + traceback.format_exc())
if isinstance(ex, urlfetch.DownloadError) or \
isinstance(ex, DeadlineExceededError) or \
isinstance(ex, CsrfException) or \
isinstance(ex, taskqueue.TransientError):
logging.warn(msg)
else:
logging.error(msg)
def set_cookie(self, name, value, expires=None):
"""Set a cookie"""
if value is None:
value = 'deleted'
expires = datetime.timedelta(minutes=-50000)
jar = Cookie.SimpleCookie()
jar[name] = value
jar[name]['path'] = u'/'
if expires:
if isinstance(expires, datetime.timedelta):
expires = datetime.datetime.now() + expires
if isinstance(expires, datetime.datetime):
expires = expires.strftime('%a, %d %b %Y %H:%M:%S')
jar[name]['expires'] = expires
self.response.headers.add_header(*jar.output().split(u': ', 1))
def render(self, name, **data):
"""Render a template"""
if not data:
data = {}
data[u'js_conf'] = json.dumps({
u'appId': conf.FACEBOOK_APP_ID,
u'canvasName': conf.FACEBOOK_CANVAS_NAME,
u'userIdOnServer': self.user.user_id if self.user else None,
})
data[u'logged_in_user'] = self.user
data[u'message'] = self.get_message()
data[u'csrf_token'] = self.csrf_token
data[u'canvas_name'] = conf.FACEBOOK_CANVAS_NAME
self.response.out.write(template.render(
os.path.join(
os.path.dirname(__file__), 'templates', name + '.html'),
data))
def init_facebook(self):
"""Sets up the request specific Facebook and User instance"""
facebook = Facebook()
user = None
# initial facebook request comes in as a POST with a signed_request
if u'signed_request' in self.request.POST:
facebook.load_signed_request(self.request.get('signed_request'))
# we reset the method to GET because a request from facebook with a
# signed_request uses POST for security reasons, despite it
# actually being a GET. in webapp causes loss of request.POST data.
self.request.method = u'GET'
self.set_cookie(
'u', facebook.user_cookie, datetime.timedelta(minutes=1440))
elif 'u' in self.request.cookies:
facebook.load_signed_request(self.request.cookies.get('u'))
# try to load or create a user object
if facebook.user_id:
user = User.get_by_key_name(facebook.user_id)
if user:
# update stored access_token
if facebook.access_token and \
facebook.access_token != user.access_token:
user.access_token = facebook.access_token
user.put()
# refresh data if we failed in doing so after a realtime ping
if user.dirty:
user.refresh_data()
# restore stored access_token if necessary
if not facebook.access_token:
facebook.access_token = user.access_token
if not user and facebook.access_token:
me = facebook.api(u'/me', {u'fields': _USER_FIELDS})
try:
friends = [user[u'id'] for user in me[u'friends'][u'data']]
user = User(key_name=facebook.user_id,
user_id=facebook.user_id, friends=friends,
access_token=facebook.access_token, name=me[u'name'],
email=me.get(u'email'), picture=me[u'picture'])
user.put()
except KeyError, ex:
pass # ignore if can't get the minimum fields
self.facebook = facebook
self.user = user
def init_csrf(self):
"""Issue and handle CSRF token as necessary"""
self.csrf_token = self.request.cookies.get(u'c')
if not self.csrf_token:
self.csrf_token = str(uuid4())[:8]
self.set_cookie('c', self.csrf_token)
if self.request.method == u'POST' and self.csrf_protect and \
self.csrf_token != self.request.POST.get(u'_csrf_token'):
raise CsrfException(u'Missing or invalid CSRF token.')
def set_message(self, **obj):
"""Simple message support"""
self.set_cookie('m', base64.b64encode(json.dumps(obj)) if obj else None)
def get_message(self):
"""Get and clear the current message"""
message = self.request.cookies.get(u'm')
if message:
self.set_message() # clear the current cookie
return json.loads(base64.b64decode(message))
上のコードをキャンバスアプリのOAuthサーバーサイドに変更して、アプリを私が望むように動作させることができました。しかし、OAuth 2.0を使用すると、本当にsigned_requestが必要になりますか？ OAuthを使用すると、signed_requestは不必要と思われ、OAuthはそれをすべて実行できます。私はむしろ多くの機能init_facebookを変更：
def init_facebook(self):
facebook = Facebook()
user = None
# initial facebook request comes in as a POST with a signed_request
if 'signed_request' in self.request.POST:
fbdata= parse_signed_request(self.request.get('signed_request'), facebookconf.FACEBOOK_APP_SECRET)
facebook.signed_request = fbdata
facebook.user_id = fbdata.get('user_id')
facebook.access_token = fbdata.get('oauth_token')
if facebook.user_id:
graph = GraphAPI(facebook.access_token)
user = graph.get_object("me") #write the access_token to the datastore
fbuser = FBUser.get_by_key_name(user["id"])
#logging.debug("fbuser "+fbuser.name)
self.user = fbuser
if not fbuser:
fbuser = FBUser(key_name=str(user["id"]),
id=str(user["id"]),
name=user["name"],
profile_url=user["link"],
access_token=facebook.access_token)
fbuser.put()
elif fbuser.access_token != facebook.access_token:
fbuser.access_token = facebook.access_token
fbuser.put()
# try to load or create a user object
if facebook.user_id:
logging.debug("loading facebook.user_id")
user = FBUser.get_by_key_name(facebook.user_id)
if user:
# update stored access_token
if facebook.access_token and \
facebook.access_token != user.access_token:
user.access_token = facebook.access_token
user.put()
# refresh data if we failed in doing so after a realtime ping
if user.dirty:
user.refresh_data()
# restore stored access_token if necessary
if not facebook.access_token:
facebook.access_token = user.access_token
if not user and facebook.access_token:
me = facebook.api('/me', {'fields': _USER_FIELDS})
try:
friends = [user['id'] for user in me['friends']['data']]
user = FBUser(key_name=facebook.user_id,
id=facebook.user_id, friends=friends,
access_token=facebook.access_token, name=me['name'],
email=me.get('email'), picture=me['picture'])
user.put()
except KeyError, ex:
pass # ignore if can't get the minimum fields
self.facebook = facebook
self.user = user
は、今ではそれがとにかくしなければならなかった理由は、私がunderstodd決してGETにPOSTから方法を変更するのではなく、OAuthのを使用しています。私はもっとコードを持っているかもしれませんが、もし私がこれを間違っていると言えば、すでに基本的な例に戻るべきです。
は、例えば、私は、ユーザーがログアウトするいくつかの問題を抱えていたと私は、カスタム・ログアウト・ハンドラを記述する必要がありました：
class FBLogoutHandler(webapp2.RequestHandler):
def get(self):
logging.debug('in fblogout')
current_user = main.get_user_from_cookie(self.request.cookies, facebookconf.FACEBOOK_APP_ID, facebookconf.FACEBOOK_APP_SECRET)
if current_user:
graph = main.GraphAPI(current_user["access_token"])
profile = graph.get_object("me")
accessed_token = current_user["access_token"]
logging.debug('setting cookie')
self.set_cookie("fbsr_" + facebookconf.FACEBOOK_APP_ID, None, expires=time.time() - 86400)
logging.debug('redirecting with token '+str(accessed_token))
self.redirect('https://www.facebook.com/logout.php?next=http://www.facebook.com&access_token=%s' % accessed_token)
def set_cookie(self, name, value, expires=None):
if value is None:
value = 'deleted'
expires = datetime.timedelta(minutes=-50000)
jar = Cookie.SimpleCookie()
jar[name] = value
jar[name]['path'] = '/'
if expires:
if isinstance(expires, datetime.timedelta):
expires = datetime.datetime.now() + expires
if isinstance(expires, datetime.datetime):
expires = expires.strftime('%a, %d %b %Y %H:%M:%S')
jar[name]['expires'] = expires
self.response.headers.add_header(*jar.output().split(': ', 1))
def get_host(self):
return os.environ.get('HTTP_HOST', os.environ['SERVER_NAME'])
このソリューションでは、私は私のキャンバスアプリのためにそこにあるかの選択肢だろう最善ではないかもしれませんか？
おかげ