I am developing a web application using Facelets and Entity-Controller-EJB structure. In the application, there are contents which are reachable only if you are logged. A bean checks the login state every time you click on a button/link for the restricted contents, and redirects you either to the selected page or to the login page.
I thought that this way is not safe, as you can write the link directly in the browser instead of generating it from a button that checks the bean. So what should I do? Is there a render option embeddable in each page or should I write a javascript function? In this case, what should I do? I have studied js fundamentals but don't really know how to implement this control!
Thank you for reading!
You cannot rely only on frontend to deny access to some parts of a web application.
This because all the HTML/CSS/Javascript is downloaded on users' browser, so they can read your code and your authentication mechanism, and understand how to bypass it (or just disable it).
More on this: Why are browsers allowed to display client-side source code?
What you need is implementing some security mechanism in the backed.
The simplest one is to delegate this to your webserver (here the instructions for Apache) and then use something similar to this to do login.
Another way is to have a proper backend: you send data to it (email/password) and it provides you a token that you use to access protected resources.
Or also, dinamically create your documents on server side, only if the user is authenticated.
Related
I'm need to automatically perform the login at: http://gsc.klub-modul.dk/. After I am logged in, I need to able to fetch pages from this domain, which requires me to be logged in. As far as I have gathered, the site is using ASP.NET to interact with the server. I am open to all suggestions. I'm looking for a script to do this, as I am still new to this.
What you are trying to do is botting (Automated access of site or online game),so follow these steps,
Generic steps
Monitor the HTTP request being made by the browser (I use
Fiddler,you might also find browser built-in network tool(press F12) handy)
You need to look for cookies especially.
In short you should be able to make same HTTPRequest on each event
(by event I mean first time page request ,page submit for login and
etc)
Use python for botting
use these libraries Mecanize / twill /scrapy / Beautiful Soup
Tutorials to get started
http://docs.python-guide.org/en/latest/scenarios/scrape/
http://www.pythonforbeginners.com/python-on-the-web/web-scraping-with-beautifulsoup/
http://arunrocks.com/easy-practical-web-scraping-in-python/
https://classic.scraperwiki.com/docs/python/python_intro_tutorial/
Stackoverflow links
Scraping sites that require login with Python
Scrape a web page that requires they give you a session cookie first
Fake a cookie to scrape a site in python
Python Scraping Web with Session Cookie
My Advice
I think if you haven't made a web scraper (web-bot or bot-tool) before than you should start with small things like fetching a specific information from a page which doesn't require login then move on to more complex scenarios
As usual Asp.Net uses cookies for session, authorization needs. So basically you just need to make POST request to login page with Login, Password parameters, then you need to obtain cookies from response, and then make new requests for needed pages with these cookies.
By default these cookies are named ASP.NET_SessionId and ASPXAUTH
I have worked on a similar problem but used a generic approach. I used greasemonkey addon in firefox to login on a game and save data on different db. Later I found out that I could've wrote a addon myself (mozilla ref)
Both of these technique will rely on javascript only.(example of a login script of fb in greasemonkey)
The website was on asp.net too! You just need to receive the cookies and login from javascript code. Jsoup is another approach to parse data and login.
I'm building a website that is functionally similar to Google Analytics. I'm not doing analytics, but I am trying to provide either a single line of javascript or a single line iframe that will add functionality to other websites.
Specifically, the embedded content will be a button that will popup a new window and allow the user to perform some actions. Eventually the user will finish and the window will close, at which point the button will update to a new element reflecting that the user completed the flow.
The popup window will load content from my site, but my question pertains to the embedded line of javascript (or the iframe). What's the best practice way of doing this? Google analytics and optimizely use javascript to modify the host page. Obviously an iFrame would work too.
The security concern I have is that someone will copy the embed code from one site and put it on another. Each page/site combination that implements my script/iframe is going to have a unique ID that the site's developers will generate from an authenticated account on my site. I then supply them with the appropriate embed code.
My first thought was to just use an iframe that loads a page off my site with url parameters specific to the page/site combo. If I go that route, is there a way to determine that the page is only loaded from an iframe embedded on a particular domain or url prefix? Could something similar be accomplished with javascript?
I read this post which was very helpful, but my use case is a bit different since I'm actually going to pop up content for users to interact with. The concern is that an enemy of the site hosting my embed will deceptively lure their own users to use the widget. These users will believe they are interacting with my site on behalf of the enemy site but actually be interacting on behalf of the friendly site.
If you want to keep it as a simple, client-side only widget, the simple answer is you can't do it exactly like you describe.
The two solutions that come to mind for this are as follows, the first being a compromise but simple and the second being a bit more involved (for both you and users of your widget).
Referer Check
You could validate the referer HTTP header to check that the domain matches the one expected for the particular Site ID, but keep in mind that not all browsers will send this (and most will not if the referring page is HTTPS) and that some browser privacy plugins can be configured to withhold it, in which case your widget would not work or you would need an extra, clunky, step in the user experience.
Website www.foo.com embeds your widget using say an embedded script <script src="//example.com/widget.js?siteId=1234&pageId=456"></script>
Your widget uses server side code to generate the .js file dynamically (e.g. the request for the .js file could follow a rewrite rule on your server to map to a PHP / ASPX).
The server side code checks the referer HTTP header to see if it matches the expected value in your database.
On match the widget runs as normal.
On mismatch, or if the referer is blank/missing, the widget will still run, but there will be an extra step that asks the user to confirm that they have accessed the widget from www.foo.com
In order for the confirmation to be safe from clickjacking, you must open the confirmation step in a popup window.
Server Check
Could be a bit over engineered for your purposes and runs the risk of becoming too complicated for clients who wish to embed your widget - you decide.
Website www.foo.com wants to embed your widget for the current page request it is receiving from a user.
The www.foo.com server makes an API request (passing a secret key) to an API you host, requesting a one time key for Page ID 456.
Your API validates the secret key, generates a secure one time key and passes back a value whilst recording the request in the database.
www.foo.com embeds the script as follows <script src="//example.com/widget.js?siteId=1234&oneTimeKey=231231232132197"></script>
Your widget uses server side code to generate the js file dynamically (e.g. the .js could follow a rewrite rule on your server to map to a PHP / ASPX).
The server side code checks the oneTimeKey and siteId combination to check it is valid, and if so generates the widget code and deletes the database record.
If the user reloads the page the above steps would be repeated and a new one time key would be generated. This would guard against evil.com from page scraping the embed code and parameters.
The response here is very thorough and provides lots of great information and ideas. I solved this problem by validating X-Frame-Options headers on the server-side , though the support for those is incomplete in browsers and possibly spoofable.
I know this has been asked a bunch of times, but I have only seen serverside solutions.
I'm running an iframe app that is embedded into a page as a tab. I want be test to see if the page is liked or not without prompting the user for anything.
Is there a way to do this with just JavaScript? The platoform we are building on is ASPX and I dont really have the option of going serverside.
Its not available because you need to inspect the http post parameter called signed_request and this isn't available on the client side. If the user has authenticated with your app and given you permissions to read their likes/interests, then you could then check with javascript api but I'm guessing you wouldn't want to make them approve your app just for this.
I'm having issues trying to figure out how to generate on server side a PDF from a javascript-heavy webpage that is served from Tomcat (the application is Pentaho CE). The content is a dashboard that responds to user interaction. Pentaho (the application) replaces divs dynamically with various content through AJAX calls. I'd like to export to pdf whatever state the user has the dashboard at. There are no restrictions on what I can put on the server, but I need to avoid having the client install anything.
I've taken a look at this, along with a bunch of other google-fu:
JSP/HTML Page to PDF conversion
wkhtmltopdf seems to be a popular choice; before I start banging my head against it, I have a few questions:
Can wkhtmltopdf handle going to password protected jsps where authentication is handled by the application? Would the dynamically loaded divs break it?
Is there a way to perhaps return the client view to the server for processing? I read about screen capturing...
Another option that could work out would be to automate a local access to the dashboard on the server through a server-hosted web browser and generate a PDF that way...is this possible, given the constraints of Tomcat and password protection that's handled by the application? The javascript components that Pentaho generates cannot be accessed outside of the application.
Thanks!
EDIT:
Good news! wkhtmltopdf works! Kind of. I got past the password authentication through putting the login details through a query string, and I'm getting a pdf of the correct page now. The issue is that no javascript components are showing up... (they work for pages like yahoo.com, so maybe I'm missing something here).
If you have a lot of AJAX calls you should wait for them. Use the --javascript-delay x argument, where is x is the time to wait.
I have an HTML5 app which is capable of running offline. However, I need to password protect the directory this app resides in to only allow access to authorized users. Initially I was using a PHP login page which set a cookie (outside of the app directory) then redirected to the app directory. The app (JavaScript) checks for the cookie and if it's there it lets the user run the app. If not, it redirects them back out of the app directory.
The problem with this method is that all of the files in the directory are still accessible if referenced directly (which I don't want). I do not want users to have to authenticate every time they hit the directory (it's a one-time authentication process; the cookie is there so that they never have to type their username/password again), and I also want to have a stylized login form (i.e. not using the default browser login box for http authentication).
Finally, because this is an offline HTML5 app, I can't include any PHP code in the app itself.
Any suggestions?
That doesn't sound like something you could do from Javascript. The script would need access to the file system to be able to restrict access to the folder, wouldn't it?
Unless this feature is exposed by the browser via a javascript API, I don't think it will be possible. It sounds like it would be a useful feature though.
Perhaps you could encrypt vital data, but apart from slowing down the application, I'm not sure what good it would do, since all the necessary keys would have to be stored locally as well...
Since the general rule of security on the web is that you can never ever rely on anything that happens client-side (e.g. in Javascript) without a double check on the server-side, this will of course pose a problem when the app is running offline and the server-side is not available :(
Looking at the "make Javascript redirect if the cookie exists" problem, unless I'm mistaken, it would be trivial for a malicious user to edit the Javascript, using for example Firebug, to redirect in any case.
EDIT: By the way, what level of security are you looking for? The "mom won't be able to accidentally access my account"-level (which it sounds like you already achieved), or the "no one, except maybe the NSA, should be able to hack it"-level?