I'm developing a small CMS in PHP and we're putting on social integration.
The content is changed by a single administrator who as right for publishing news, events and so on...
I'd to add this feature, when the admin publishes something it's already posted on facebook wall. I'm not very familiar with facebook php SDK, and i'm a little bit confused about it.
If (make it an example) 10 different sites are using my CMS, do I have to create 10 different facebook application? (let's assume the 10 websites are all in different domains and servers)
2nd, is there a way for authenticating with just PHP (something like sending username&password directly) so that the user does not need to be logged on facebook?
thanks
You might want to break up your question in to smaller understandable units. Its very difficult to understand what you are driving at.
My understanding of your problem could be minimal, but here goes...
1_ No you do not create 10 different facebook application. Create a single facebook application and make it a service entry point. So that all your cms sites could talk to this one site to interact with facebook. ( A REST service layer).
2_ Facebook api does not support username and password authentication. They only support oauth2.0. Although Oauth is not trivial, but since they have provided library for that, implementing authentication is pretty trivial.
Please read up on http://developers.facebook.com/docs/.
Its really easy and straight forward and well explained.
Your question is so vague and extensive that it cannot be answered well here.
If you experience any specific implementation problems, this is the right place.
However to answer atleast a part of your question:
The most powerful tool when working with facebook applications is the Graph API.
Its principle is very simple. You can do almonst any action on behalf of any user or application. You have to generate a token first that identifies the user and the proper permissions. Those tokens can be made "permanent" so you can do background tasks. Usually they are only active a very short time so you can perform actions while interacting with the user. The process of generating tokens involves the user so that he/she has to confirm the privileges you are asking for.
For websites that publish something automatically you would probably generate a permanent token one time that is active as long as you remove the app in your privacy settings.
Basically yuo can work with any application on any website. There is no limitation. However there are two ways of generating tokens. One involves on an additional request and one is done client side, which is bound to one domain oyu specifiedin your apps settings.
Addendum:
#ArtoAle
you are right about every app beeing assighend to exactly one domain. however once you obtained a valid token it doesnt matter from where or who you use it within the graph api.
let me expalin this a little bit:
it would make no sense since it is you doing the request. there is no such thing as "where the request is coming from". of course there is the "referer" header information, but it can be freely specified and is not used in any context of this.
the domain you enter in your apps settings only restricts where facebook redirects the user to.
why?
this ensures that some bad guy cannot set up a website on any domain and let the user authorize an app and get an access token with YOUR application.
so this setting ensures that the user and the access token are redirected back to YOUR site and not to another bad site.
but there is an alternative. if you use the control flow for desktop applications you don't get an access token right after the user has been redirected back. you get a temporary SESSION-TOKEN that you can EXCCHANGE for an access token. this exchange is done server side over the REST api and requires your application secret. So at this point it is ensured that it is YOU who gets the token.
This method can be done on any domain or in case of desktop applications on no domain at all.
This is a quote from the faceboo docs:
To convert sessions, send a POST
request to
https://graph.facebook.com/oauth/exchange_sessions
with a comma-separated list of
sessions you want to convert:
curl client_id=your_app_id \
-F client_secret=your_app_secret \
-F sessions=2.DbavCpzL6Yc_XGEI0Ip9GA__.3600.1271649600-12345,2.aBdC...
\
https://graph.facebook.com/oauth/exchange_sessions
The response from the request is a
JSON array of OAuth access tokens in
the same order as the sessions given:
[ {
"access_token": "...",
"expires": 1271649600, }, ... ]
However you don't need this method as its a bit more complex. For your use case i would suggest using a central point of authorization.
So you would specify your ONE domain as a redirect url. This domain is than SHARED between your websites. there you can obtain the fully valid access token and seamlessly redirect the user back to your specific project website and pass along the access token.
This way you can use the traditional easy authentication flow that is probably also more future proof.
The fact remains. Once the access token is generated you can perform any action from any domain, there is no difference as ther is literally no "domain" where the request is coming from (see above).
apart from that, if you want some nice javascript features to work - like the comments box or like button, you need to setup up open graph tags correctly.
if you have some implementation problems or as you said "domain errors" please describe them more clearly, include the steps you made and if possible an error message.
Related
This got stuck in my head from many days, can anyone help or say at-least this is not at all possible?
I'm working on developing a chat bot using dialogflow which integrates multiple applications along with google home assistant, dialogflow, actions on google and an application which i want to manage using chat or voice commands. Until now its good and got amazed of features providing by google.
But i'm expecting one more feature. Don't know whether any alternatives available for this or not, but i tried exploring and reached to desert. Below are my requirements, if others think this is really unique and useful to them as well then i can say they are improvements or add-ons i'm expecting from DialogFlow.
Let's take an example of a chat bot which is serving users through google assistant and as a web bot as well. Now while conversing, intents may trigger web-hook in fulfillments which may require an authentication like OTP(Nope if anyone thought it for payments) which means registered users or limited users only can perform actions. This is same as we use roles and groups in all the applications.
The way google is sending google prompt to the user for logging into gmail, is there any way that we can collect PIN or OTP or PASSWORD through some notification sent to the users phone as some card's or input box like and html while conversing with chatbot through web or home assistant etc..., so that it helps in adding more security.
I recently worked in a chatbot project where I had to authenticate my users. I'm writing an article about it, but I'll tell you what I did:
First of all, I'm using OAuth 2.0 protocol to authenticate my users, but if you doesn't use OAuth, there's no problem, you could do something equivalent.
I'm using Authorization Code Grand flow.
Let's see the steps:
Step 1 - Authorization Url:
My bot generates an authorization url which contains all needed data to identify the conversation in callback moment. Like this one:
https://authorization-server.com/oauth/authorize
?client_id={your-client}
&response_type=code
&state={conversation_id: 123456789}
&redirect_uri={your-callback-url}
Notice that the state parameter contains the conversation_id which identifies your conversation, this state parameter will be back when users return to your handler.
Step 2 - User Authentication
When users click in this link, they'll be redirected to your login page at your authorization server.
Step 3 - Callback
After users get authenticated, they'll be redirect back to your handler (an endpoint which will receive the authorization code from authentication server and the state parameter).
When it received this authorization code, it'll be exchanged by an access token in authorization server.
Step 4 - Store token
In the final step, you already has an access token and the conversation_id parameter, you can store it in a database, in a cache or be stateless. Your rules!
In my case, I'm using Watson Assistant with Cloudant database, and I store those access tokens in my database. So, when users request something to my bot, it could get this token from database and pass to my back-end servers.
This kind of approach, I call "magic link". And you could improve it by shortening the url as bit.ly does.
I hope it could help you, feel free to ask me if you need.
Best
You probably don't want to implement the OTP scheme yourself. While you could do this, there are other systems already in place that will do this for you.
The best is the one that you reference - Google Sign In.
Fortunately, you can leverage Google Sign In for both your website (where you would get the user to sign in and then pass this information along as you do the Dialogflow calls) and for the Assistant (where Google will pass along an ID token, indicating it has authenticated the user).
I'm new to OAuth and I would really appreciate if someone could give me a hand with my problem. I need to create a simple web application for track expenses, with some basic actions (user must be able to create an account and log in, list expenses, edit them, etc) with a REST API for each one, and the trick is that I need to be able to pass credentials to both the webpage and the API. So, after some research I've found some examples using Digest Authentication and HMAC Authentication but lot of posts also mentioned OAuth as an alternative approach, so my question is, given this scenario, would be proper to use OAuth? I mean, as far as I understand OAuth is suitable when you want to share resources with other application, which I'm not doing for this project; besides that, when you try to access the shared resource it appears a page requesting permission for the foreign application, would that page appear at some point in my application? (maybe after the login?)
Thanks in advance guys
In your current scenario it does not make sense to use OAuth. It's not what OAuth is designed for.
If your application ecosystem is going to have multiple webapps running on a single SSO (like google) then it is very helpful to have OAuth.
Suggestion: Decide based on your business/operation plan and implement accordingly.
Note: If you plan to have 10 apps in the span of the next 5 years but only have one app now it does not make sense to spend time to implement complex protocols like OAuth right now. Scale as you grow.
We intend to develop rest based api. I explored the topic but it seems, you can secure api when your client is an app (So there are many ways, public key - private key etc). What about websites / mobile website, if we are accessing rest based api in website which do not use any login for accessing contents ( login would be optional ) then how could we restrict other people from accessing rest based api ?
Does it make sense using Oauth2.0 ? I don't have clear idea of that.
More clear question could be ,How can we secure get or post request exposed over web for the website which doesn't use any login ?
If it's simple get request or post request , which will return you json data on specific input, now i have mobile website , who will access those data using get request or post request to fetch data. Well, some else can also access it , problem is i am not using Login, user can access data directly. But how can we restrict other people from accessing that data.
What do you think is the difference between securing a website that is not using REST vs one that is using REST API?
OAuth provides authorisation capabilities for your site, in a REST architecture this means a user of the mobile application will have to provide their credentials before being allowed to access the resource. The application can then decide on if that user has access to the requested resource. However you've said your website doesn't need use authorisation.
You can use certificates however good luck managing the certificate for each client. My take on it is for your explanation you don't need to secure your website because you will never be able to manage a trust relationship between the client and the server. There are some options though:
You build your own client application that you ship out to people which can verify itself with the server using a packaged certificate with the client. E.g. iOS has this kind of feature if you build for that device.
You provide a capability to download a certificate that is 'installed' in the browser and used when communicating to your REST API
Use something like a handshaking protocol so when a client wants to make the first request it says; 'hi I'm a client can we chat?' And the server responds with 'yes for the next X minutes we can however make sure you send me this key everytime you tell me something YYYYYY' (you can use something like SecureUDID or equivalent for other devices than iOS).
There are probably others but you get the basic idea. Again in my opinion if your resource doesn't need authorisation then you don't need to secure that REST API. Can I ask what kind of data are you exposing via this REST API or functionality your providing? That might help provide a better answer.
You want authorization: only some agents (mobile clients) and/or users should be allowed to access those APIs.
To solve that problem, you need identification: a way for the server to tell who is who (or what), so the right decision can be made.
There are many different way to provide some form of identification, depending how much you care about security.
The simplest is a user agent string, specific to your mobile clients. But it can be faked easily. Slightly harder to fake are client based 'secrets' - embed some kind of secret or key in your mobile client code. You can make it really complicated and secret, but as ramsinb pointed out, you can't get security this way as it would require you to be able to guarantee that the secret you're shipping with the client (wether it's code, algorithm or any other fancy construct) can't be compromised or reverse engineered. Not happening when you don't control the client.
From there, 3 choices:
Security isn't really required, don't bother
Security isn't really required, but you still want to limit access to your API to either legit users/agents or people ready to invest some time hacking your protection - go with a specific user agent or a client embedded secret - don't invest much into it as it won't block people who really want access to get it anyway
Security IS required - and then I don't think there is a way around authentication, wether it's login/password, user specific (device specific?) keys, OpenID, etc... No matter what, you'll have to add to the user burden to some extent, although you can limit that burden by allowing authentication to persist (cookies, storage....)
I have a Facebook canvas app. I am using the JS SDK to authenticate the user on the browser-side and request various information via FB.api (e.g. name, friends, etc.).
I also want to persist some additional user information (not held on Facebook) to the database on my server by making an ajax call:
{ userFavouriteColour: "Red" }
To save this on the server and associate with the correct user, I need to know the Facebook uid and this presents a problem. How do I pass the uid from the client to the server.
Option 1: Add uid to the ajax request:
{ uid: "1234567890",
userFavouriteColour: "Red" }
This is obviously no good. It would be trivial for anyone to make an ajax request to my web service using someone else's Facebook Id and change their favourite colour.
Option 2: On the server, extract the uid from a cookie:
Is this even possible? I have read that Facebook sets a cookie containing the uid and access token but do I have access to this cookie on my domain? More importantly, can I securely extract the uid form the cookie or is this open to spoofing just like option 1.
Option 3: User server-side authentication on the server:
I could use the server-side authentication to validate the user identity on my server. But will this work if I am already using client-side authentication on the browser? Will I end up with two different access tokens? I would like to make FB.api requests from the browser so I need the access token on the client (not just on the server).
This must be a very common scenario so I think I'm missing something fundamental. I have read a lot of the Facebook documentation (various authentication flows, access tokens, signed_request, etc.) and many posts on SO, but I still don't understand how client-side authentication and server-side authentication play nicely together.
In short, I want to know the user's identity on the server but still make requests to the Facebook api from the client browser?
(I am using ASP.NET and the Facebook C# SDK on the server)
EDIT: Added bounty. I was hoping to get a more deifnitive, official recommendation on how to handle this situation, or even an example. As said, I have already read a lot of the official FB docs on authentication flows but I still can't find anything definitive on how client-side and server-side authentication work together.
Option 1:
The easiest way I can think of is to include the accessToken in JS and pass it with the ajax call.
Option 2:
Using the same as option 1, but instead of sending just the accessToken, send the signedRequest.
On the server side you can decode it using (TryParseSignedRequest method) which will give you the UserID :-)
Note: signedRequest is encrypted with the application Secret. you are the only one who should know it, so you are safe on that end.
Disclaimer:
I have no coding experience in C#, but a little search in google gave me this:
Facebook C# SDK for ASP.NET
Making AJAX Requests with the Facebook C# SDK
It's very simple actually.
When the user loads you app use the server side authentication, get the access token and load the user data by issuing an api request from the server.
On the server side you'll have everything you need and it's sandboxed.
When the page renders for the user, using the js sdk get the user authentication data, you should be able to use FB.getLoginStatus since the user already went through the server side authentication.
Now on the client side you also have an access token which you can use to get the user data from the graph api.
The two tokens will be different, and will also have different expiration, but that should not be a problem, both token should work properly as you'd expect them to.
Since both sides have their own token and a way to make requests to the api, there's no need to send any fb data between them.
So the 3rd option you mentioned, to me, sounds the best, and it's really simple to implement that too.
Edit
All facebook SDKs are just wrappers for http request since the entire fb api is made on http requests.
The SDKs just give you easy and shorter access to the data with out the need to build the url yourself (with all the different possible parameters), make the request and parse the response.
To be completely honest, I think that stop providing a way for the C# SDK to support server side authentication is a very bad decision.
What's the point in providing a SDK which does not implement the entire api?
The best answer to your question, from my experience, is to use both server and client side authentication, and since the C# SDK does not support it, my advice to you is to create your own SDK.
It's not complicated at all, I already implemented it for python and java (twice), and since you'll be developing it for your own needs it can be tailored for your exact needs, unlike a public SDK which should support all possible options.
2nd Edit
There's no need to create a completely new SDK, you can just "extend" the ones you're using and add the missing parts that you need, like sever side authentication support.
I don't know if it's language specific but using both server-side and client-side authentication does no harm.
You can work on option 2 but yes, that will be also vulnerable to spoofing.
Doing option 3, you will be having a single access token for that user session, so that would be the best choice according to me since you always have chance of spoofing when passing user information from client side.
I had exactly the same question recently. It's option 2. Check this post from the Facebook blog.
To be honest I am not enough of a hacker to know if you could spoof the UID in the cookie, but this seems to be the 'official' way to do it.
EDIT: to the other question under option 2, yes, I believe you have to access this cookie on your domain.
i'm in the early stages of developing an API for my site so that third party developers can build an iPhone application for it. The API would have a limited subset of the functionality of the full site. The trouble i have is around security and authentication for the user who downloads the application. I have come up with the following options:
The user enters the same credentials they use on the site to authenticate themselves. My API would then take the credentials when accessing information specific to the user. This is my least preferred solution as the third party application could log these details and use them maliciously on the full site.
Each user generates a unique key on the site which they can then use on the app to login. My API would take the api key as an argument when accessing information specific to the user. The main problem though is that any application can do what they like to the user once they gain access to their key even if the user has not given the application permission to do so.
To overcome the above problem the third party developer would have to register their application with the site and then the user would need to generate a unique key per application they wish to use. This would then be used to login. This is my preferred solution as each key is unique per application and user i can tell which application called the api and whether the user approved it.
My final option is to implement oAuth. We are currently waiting for the 2.0 version to be finalized and do not have the time to keep updating our code as the spec may change.
This is the first API i have had to build and i was wondering if i have understood this correctly? I'm assuming in option 1 the application could log the user credentials and use them maliciously but how does twitter overcome this issue with their third party applications? Or is it simply up to the user to trust the application they are using? If this is the case then would option 2 and/or 3 be feasible in the meantime until i switch to option 4.
I'd appreciate your feedback. Thanks
OAuth 1 and OAuth 2 are both viable options. But you will come a long way with basic authentication aswell (as long as it is over SSL). Don't be scared :)
I've implemented an API provider over OAuth 1.0. And since there are so many ready made libraries for OAuth1.0 for many platforms I would not be scared of using that either, much of the work has been done already, both for you as a provider and for third party implementors.
Anyway: you can always couple basic authentication with some very simple signing of the request using an application key and secret, say for example that as a third party developer you have to call.
https://yourapi.com/?user=11111&password=232123&random_string=23123&api_key=THIRD_PARTY_KEY×tamp=1212121212signature=efefefefefef
where the API implementor has to sign perhaps the random_string, timestamp and api_key with the secret. Then you would at least have a way of shutting down malicious apps.