I'm developping a backend REST API for a mobile app and I am now looking to implement token-based authentication for it to avoid having to prompt the user to login on every run of the app ..
the user will have a token for a certain time before being obligated to give the username and password again, it's like managing sessions that have limited among of time, anyway I've gone through the APIs that provides this kind of Authentication mechanism and notice that OAuth is highly rated but haven't found any exemple that suits my cas ..
I do't know if this is the good way to ensure authentication for app or there's other mechanisms ..
if you have any suggestions, ideas or any sort of help, feel free to comment ..
Related
I have a website and my own server and database, I also have an native Android app. I need to allow users to be able to sign-in with their account from the website inside the app in order to sync information and other things they need to use. I've been stuck for a couple of days trying to figure out how to do that. I've found a lot of content regarding OAuth and AppAuth but they are focused on using an OAuth API to the job. Back on my server, I use Hybridauth for social login, but users can also register directly on the site. How would be the proper way to allow my users to sign-in to their website account through the Android app?
You're overthinking it. OAuth isn't meant for users to log in, it's meant to enable external services to access data on behalf of a user.
To make a user log in? Create a POST endpoint on your webservice named login. It should take two parameters- username and password. The body of the login service should salt and hash the password, then check if the hash equals the hash stored in the db for the same user. If so, you're logged in and you return a success packet with a unique token to authenticate you for later requests. If not, you return a failure. The Android app would ask the user for their data, then send a request to the endpoint. On success it saves the token and sends it in all future requests to authenticate yourself, either as a parameter or as a header.
This is of course the simplest possible version. More advanced features would include expiring of login tokens, refresh tokens, possible lockout if you have too many bad requests, etc. But the above is the basic idea. Although really I'd look for an open source solution you can take, as there's quite a lot of complexity when you get into all the stuff mentioned above, and its a place where a mistake that leads to a vulnerability is probably the most dangerous.
I am trying to write an external Java application that collects posts from Yammer using its REST API and I am experiencing issues with the authentication part.
To extract the data I want a regular yammer user (I do not have admin permissions) to be authenticated automatically from the Java application without any prompts. Does anyone know whether this is feasible and moreover - whether it is feasible in a SSO-enabled network? If yes, what kind of authentication libraries should I use? Is there some documentation/sample code snippet describing how to log in to Yammer via Java and not via a Yammer app?
I've seen that there are similar questions here, but are still unanswered.
I will appreciate any know-how on the topic!
Thanks!
The only way to authenticate to yammer without any prompt is to pass a persistent oauth token as an authorization bearer token in your request header. The caveat is, users cannot be dynamic.
It is pretty simple to generate the access token. For that you need client Id and client Secret.Steps are available in https://developer.yammer.com/v1.0/docs/test-token.
But if you don't have that information, go to https://developer.yammer.com and log on with the credentials and try some Rest API(Try It Out section) in the developer site. Copy the Authorization code from the Request Headers and you can use it in your application.
Note: Access Tokens for users are long lived, expiring when users are suspended, change their Yammer password (non-SSO networks only), or users manually revoke them
I know that CAS is a single sign-on protocol for the web. Its purpose is to permit a user to access multiple applications while providing their credentials (such as userid and password) only once. It also allows web applications to authenticate users without gaining access to a user's security credentials, such as a password.
So, How can i use Jasig CAS server for android mobile applications ? some guidelines would be very useful!
Actually there exist two ways of doing this, each of them has some drawbacks.
1) Expose the REST interface (here you'll find a simple JAVA client that consumes them and a iOS sample how to use it on a mobile)
The problem here is that if somebody downloads your application from the store and checks the network traffic in it (or simply decomposes it) he'll find the calls you make. With this he could create an APP that does the same as you do, and log the passwords entered by the users (like a man-in-the-middle attack)
2) Open the real website in a web view inside your APP
You'll need to create a modle login page, or a responsive one on your CAS server so that it looks nice. Obviously even here somebody could theoretically copy your APP and the Website on your CAS fake both to look like your APP grab the username and password and send it in background to your CAS to give to the user the impression that everything went right but it is much more complex.
However even here u'll need to tweak the CAS; CAS is designed to accept a login for a service to which it would redirect after successful login. Therefore in this case you'll need to add a fake service to the CAS configuration and check if the webview will redirect to it. when that happens u'll find the TGT in the CASTGC cookie.
In our first APPs we used the REST version, but then as we use our CAS for websites too we wanted to restrict the REST access only to other servers in the facility, so we came up with the second solution which seems to fit better, but overall CAS seems not to be prepared for mobile APPs
You can set up CAS in order to expose REST service, this allow to validate credentials.
Documentation: https://wiki.jasig.org/display/casum/restful+api
My company is building a RESTful API that will return moderately sensitive information (i.e. financial information, but not account numbers). I have control over the RESTful API code/server and also am building the Android app. I've setup the API to use OAuth 2 with authorization code grant flow (with client ID and secret), and I auto-approve users without them having to approve the client since we own both client and provider. We use CAS for SSO and I am using this for the Authorization server as part of the OAuth 2 process when the user logs in to retrieve the token.
I am contemplating various ways to secure the data on the Android app. I've concluded that storing the client id and secret on the device is definitely not going to happen, but am thinking that storing the auth token might work, since it is only risk to the individual user (and really only if they happen to have a rooted phone).
Here are two options I have thought of. They both require me to have a sort of proxy server that is CAS protected, does the dance with the API server, and returns the auth token. This gets rid of the need for storing the client id and secret in the app code.
Here are what I've come up with:
1) Require the user to enter their password to access data each time they startup the App. This is definitely the most foolproof method. If this were done, I'd probably want to save the userID for convenience, but in that case couldn't use the CAS login (since it's web-based). I might be able to use a headless browser on the backend to log the user into CAS and retrieve the token based on what they enter in the Android form, but this seems hacky. Saving the userID is similar to what the Chase app does (if you happen to use this one) - it saves the userID but not your password between sessions.
2) Store the auth token on the Android device. This is a little less secure, but almost foolproof. When the user starts the app for the first time, open the webpage to the CAS login of the proxy server that returns the token (similar to https://developers.google.com/accounts/docs/MobileApps). After the user logs in and the token is returned to the app, encrypt it and store it private to the application. Also, use ProGuard to obfuscate the code, making the encryption algorithm more difficult to reverse engineer. I could also work in a token refresh, but I think this would be more of a false sense of security.
3) Don't use CAS but come up with another way to get an auth token for the service.
Any advice of how others have implemented similar scenarios (if it's been done)?
Thanks.
Well the reason why standards like OAuth are developed is that not everyone has to rethink the same attack vectors again and again. So most often it is your best choice to stick to something already available instead of baking your own thing.
The first problem with clients that are not capable of secretly storing data is that the user's data could be accessed by some attacker. As it is technically not possible to prevent this (code obfuscation won't help you against an expert attacker), the access token in OAuth 2 typically expires after short time and doesn't give an attacker full access (bounded by scope). Certainly you shouldn't store any refresh token on such a device.
The second problem is client impersonation. An attacker could steal your client secret and access your API in his own (maybe malicious) app. The user would still have to login there himself. The OAuth draft there requires the server to do everything it can to prevent this, but it is really hard.
The authorization server MUST authenticate the client whenever possible. If the authorization server cannot authenticate the client due to the client's nature, the authorization server MUST require the registration of any redirection URI used for receiving authorization responses, and SHOULD utilize other means to protect resource owners from such potentially malicious clients. For example, the authorization server can engage the resource owner to assist in identifying the client and its origin.
I think Google are the first to try another approach to authenticate a client on such devices, by checking the signature of the application, but they are not yet ready for prime time. If you want more insight into that approach, see my answer here.
For now, your best bet is to stay on the OAuth way, i.e. having the access token, client ID and client secrect (when using the authorization code grant flow) on the device, and configure your server to do additional checks. If you feel more secure obfuscating these, just do it, but always think of it as if these values were publicly available.
This is related to OpenId authentication.
I have implemented the google and yahoo openId auth with java in struts2
but it is achieved through page redirection to openId provider auth page and then back to my own success web-page.
But what i wanted was same as facebook auth. were in json object is passed from fb and fb authentication is done in a pop-up. so that redirection can be avoided.
Plz help me out.
I have somewhat implemented which is mentioned in this post part1-part4: http://javadeveloperjournal.blogspot.in/2011/08/integrating-openid-into-my-struts-2-app.html
First, i will not suggest to use OpenID for Facebook and Facebook do not provides its own implementation for the OpenID but rely on certain third party implimentations.
Best way to go with OAuth which is quite similar to what OpenID is with only differences in the level of security and authentication.
While Constructing a URL to the OAuth Dialog, you can specify a parameter namely display indicating if you want a page redirect or pop-up, by default the value of this parameter is set to page
Please go through Facebook documentation for implementing OAuth
oauth using Facebook
That redirection is an mandatory part of the OpenID specification. Anyhow to authenticate users in that manner, whoever the OpenID Provider should support it. But facebook does't as far as I know. Use Oauth, facebook supports it and it is an open standard, so it is always better to go with open standards.
Well as the other answers have indicated, that passing you to the OpenID provider to login is part of the specification. Also in agreement with Umesh above, Facebook provides Facebook Connect, which isn't OpenId, but allows you to authenticate users using this method.
See: Is Facebook an OpenID provider?
What I do want to add however is clarification that you don't just run off and create an OAuth based authentication system because OpenID isn't what you want to use. OAuth provides you with more than just login authentication, there's more power in there - which strangely users are unaware of. OpenId passes along your credentials and OAuth passes along access to your data. So with OpenId the website can authenticate me, with OAuth the website can authenticate me and possibly have access to all my email or my documents in Google Drive. The good thing is that you the user has to explicitly allow this access.
But erring on the side of privacy you'd want to build a compelling case for an application that needs the power of OAuth. Like the picture in the article below, one's the different between asking for a notarized letter to prove your identity, and asking for a valet key to prove your identity.
A valet is OAuth, I need them to take my car and park it in the parking lot, so I give them a valet key. It can't open the glove compartment or the trunk, but they can open the driver's side door and start the ignition - which is all I need them to do, and no more. However I don't give the cashier at the grocery my valet key when I'm paying with a personal check, she just needs to see a photo ID, any gov't issued ID will work. Technically my valet key which will allow her to open my car and read my VIN and possibly authenticate it against a DMV database should also work, but that's probably overkill.
There are good uses for OpenId, OAuth and Federated logins, but as developers we need to understand when and where we should use each of them.
http://en.wikipedia.org/wiki/OAuth#OpenID_vs._pseudo-authentication_using_OAuth