Let's say I've created a mobile application named 'Foo'(iOS). This app talks to a Java-running backend at 'java.com' and works perfectly. Now, I'm trying to create the website 'Foo.com' to let users enjoy the 'same' service on a browser/computer. So far, I've found that almost all calls needed to the API from the website can be done in JavaScript directly to the backend at 'java.com', including a login-function.
On the backend, I've implemented the standard 'doPost'-method to handle the login, and I create a Cookie to attach to the request.
The problem, I think, is that the users get the JavaScript from 'Foo.com', and the JavaScript tries to log in by using an AJAX-call to 'java.com', thus the cookie will be 'stamped' by www.java.com', not by 'www.foo.com', and the user will never receive the cookie. (At least, I don't receive a cookie now)
I've been trying to find a way to accept cookies from 'api.com' into the application, but it doesn't look good. Honestly, I'm not even sure this is the actual problem causing me to not receive a cookie, but I've read several places that cross-domain-cookies aren't allowed. So I ask the general question, how should I proceed?
I've been toying with the idea to add a .php-page to the server-side of the website 'foo.com', and from there handle the requests from client to API, hopefully causing the cookies to be 'stamped' as 'foo.com' instead of 'java.com'. (In that case, I'd also wonder if the .php can forward the information in the cookie or something similar).
But I really want to avoid as much traffic on the webhost as possible. An all-script-website would be optimal, but I don't really see how cookies can work with that.
Is there anything else I can do to handle this? If I simply want a persistent login-function from a client of 'foo.com' handled at 'java.com', are there any options, with or without the use of cookies?
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I want to make an application which logs into a web site by filling form, perform basic operations such as button click etc and finally log out. What package / external jars are available for this?
You need to look at java.net.URL, java.net.HttpURLConnection, and java.net.Authenticator.
In general you need to open an HTTP connection,
get the form (using GET method),
and fill in the details, and POST probably perform a POST of the login data.
Bare in mind that most sites provide some security, such as SSL , or other mechanism, you will have to deal with this in your application (the same way browser knows how to handle this).
I'm building an app to let users export data from a university system. Currently, they can log in and see the data in HTML, but I would like to let people download it as CSV.
I have an app where users supply their username and password. I would like to log in to the university system and HTML scrape the resulting page. How can I do this?
I'm building a GWT app. I could either do this in Java-transliterated-JS on the client, or Java on the server.
Update: Selenium might be nice, but it looks like overkill.
You're going to have to do this from the server unless the domains are the same. You'd need to determine what the POST transaction used by the other server for the login step looks like - parameter names etc. Then you'd perform that operation and do whatever you want with what comes back. If you need to see multiple pages, you need to maintain the appropriate session cookie too so that the server knows you're still logged in on the subsequent HTTP requests.
If you have to hit another site to validate the credentials, then I'm not so sure that people should feel comfortable providing those credentials to you. That is, if you don't have rights to check the credentials directly, why are you trustworthy to receive them? I know sometimes people need to integrate with a system they don't own, so this is just a question.
First, this has to be done server-side because of the limitations on client scripting due to the same origin policy.
The typical way of handling the "screen scraping" you mention is to treat the web page as if it was an XML service. First, examine the source code of the page, then using an internet/HTTP stack, craft a POST to the correct URL and read the response using a standard XML library. It will take some ingenuity to come up with a good way to dig into the XML to find the piece you need that will be as insulated as possible from changes to the page. Keep in mind that your system can break any time that the owners of the site change their page.
Sometimes, you can't just send the POST but have to request the blank page initially in order to get hidden form values that need to be returned in the POST. You'll have to experiment to find out what it requires.
Additionally, you probably have to handle cookies as well, since they usually are an integral part of the web site's authentication and session management (though you might get lucky that the session doesn't matter between the initial POST and the first response).
Last, you may be unlucky enough that the site uses javascript to do part of the authentication work, which may require additional digging to understand how the credentials are posted to the site.
There are other potential barriers such as the site checking to see that the referrer is their own site, possible use of SSL (HTTPS) and so on.
I'm pretty sure that the protection against cross-site scripting in web browsers will mean that you can't log in to the university's app using javascript running in the web browser. So the part of your program that fetches data from the university will need to run on your server. Once you have the data, you can process it either on your server or in javascript in the browser, but I think it would be easier to do it on the server.
See http://en.wikipedia.org/wiki/Same_origin_policy
I'm not too sure about GWT, but in general, you would take the form data submitted by the user, check it against a database of username and hashed passwords. If the database checks out, set a session cookie that says the user is logged in.
In your pages, check if the session cookie say the user is logged in. If not, redirect to login page, otherwise allow them to view the pagfe.
I a deveveloping a web site that comunicates with a custom made webserver by me in Java. The web site is made in PHP/JavaScript/JQuery running on Apache and i made a simple second webserver in Java to support some designed features by me, and this server runs under another port XXXXX. The problem is, i want to make requests in jQuery to second server the domain is diferent, the page runs on domain and the $.getJSON function calls domain:XXXXX wich is not allowed. I thought user $.getJSONP but im concerning concerned issues. The connections between two points is authed (i was think by passing a token beyond the callback generated by jquery). The two poins are supported by. Is there safe in this case use $.getJSONP or exists other alternatives thinking in browsers support(IE7+ and FF3+).
Sorry for my english :)
Best regards lealoureiro
JSONP should work for your needs, however your other option would be to have a proxy service on your second server that would make the request server side. Your client-side code could then access all the data natively via json instead of jsonp.
This question is more towards Design and Architecture and I want to know SO Readers think on my scenario.
I have a requirement where in my Application should provide other application interface when the user logs in to my application.
For example, lets say my application is www.gmail.com and other application is www.stackoverflow.com so what am trying to accomplish is that when the user log's in gmail account he should see his home page of stackoverflow and a particular questions.
From technology point of view, we have to use Java and so am not sure of what design and architecture consideration would go in to implement the requirement.
One Approach, am thinking on is that when the user logs in to gmail than I will populate the request object with all the login credential parameters for stackoverflow website and also question_id which would be passed in as parameter and then on Stackoverflow side, I would parse the request object and authenticate the user credentials and depending upon request parameter, I would render the question_id which I received from request.
I want to know what would be best approach and issues encountered in designing such an system.
Edit
After seeing all the answer, I would like to add little update to my question. What I am looking for is to get the feel of issues and challenges what I would have to face while trying to accomplish my task, also I am using Java and am not sure how can I accomplish my goal using Java as we do not have something like OLE which we have in Microsoft Technology stack to achieve the task.
Hope I am making some sense here.
I can think of three ways you could solve this.
Implement single sing-on. You log-in to all enterprise applications, and once logged all of them use the same authentication credentials (I think this is the best option. you don't need a full-fledge SSO, at least for these two application you could use the same credential validation mechanism)
You could also do what your are proposing creating the authentication credential for the user (i.e a cookie) and then do a redirect. Keep in mind that both application will need to be in the same sub-domain in order to work.
As mentioned before, you could also expose through your application the data/services you want to consume from the other application.
In my company we have what we call "Graphical Services", which are managed by a central server which also do credential validation, if the credentials are right it display a user interface for the user (generally in a Pop-up or an iframe).
Hope it helps.
You can't definitely do that at client side or java script as it will lead to cross site scripting issues. Or you can use iframes (which isdeprecated).
The other way of doing it would be to have your own interface/UI for the application and use only the service layer from your back end (java/j2ee in your case) which you may end up duplicating all the front end again (on the positive side, you will get your own branding of the site).
Regarding credentialing all most all the sites now used "OAuth" or similar and it should not be that difficult for authorizing
If both applications are web-based in-house applications, you could write a master login component, independent of either application, that will perform the user authentication, load any useful data it can at login time, and send the user's browser to the correct URL, making sure to pass any relevant information to the target app (as part of the forwarding request or behind the scenes in some distributed shared memory). Just a thought.
I keep on facing this question from my manager how SSO will work if client disable cookies but I don't have any answer. We are currently using JOSSO for single sign on. Do we have any open source framework which support single sign on without using cooking mechanism.
In the absence of cookies, you're going to have to embed some parameter in each url request. e.g. after logging in you assign some arbitrary id to a user and embed that in every link such as http://mydomain.com/main?sessionid=123422234235235. It could get pretty messy since every link would have to be fixed up before it went out the door which slows down your content. It also has security, logging and session history implications which are not such a huge deal when the state is in a cookie.
It may be simpler to do a simple cookie test on logged in users and send them off to an error page if they do not have cookies enabled.
The CAS project passes a "ticket" from the sign on server to the consuming application as a url query parameter, the consuming app then makes a back channel request back to the sign on server to validate the ticket's authenticity. This negates the need for cookies and therefore works across domains however it is a bit "chatty"
Another arguably more robust solution is to use a product based on SAML which is an industry standard for cross domain single sign on. There are a couple of open source products out there which use SAML and CAS itself has a SAML extension however they are typically quite complex to setup. Cloudseal is also based on SAML and is much simpler to use. The Cloudseal platform itself is delivered as a managed service but all the client libraries are open source
Of course with all these solutions you are simply passing a security context from one server to another, the consuming application will no doubt create it's own local session so you would then need to use URL rewriting instead of cookies
Disclaimer: I work for Cloudseal :)