I was wondering if it's possible to capture a screenshot and/or record my computer screen(s) via a website?
If it is possible, what languages would I need to learn/code? I already have intermediate knowledge of HTML, CSS, JavaScript, jQuery, and PHP.
In other words: I want to have the ability to capture/record my screen (not the website) via using a website (not an application).
Thanks!
This is not possible. Web sites are very deliberately given only restricted access to your computer for security reasons. Imagine the havoc that could result if a malicious web site were able to see and capture what was on your screen--banking information, your confidential e-mails, etc. Even if the user had to give permission for this level of access, it would still be way too easy to trick a user into giving that permission.
The closest I could find/think of was http://www.screencast-o-matic.com/screen_recorder, but even then you have to download a launch plugin. I agree with #DLH. This is for your protection.
My favorite screen recorder is ScreenPresso - it is always running in background, and repurposed the PrtScn button as its launch key.
Related
I want to build a task-specific web browser. For example, when the user uses that browser, the program should give options like these:
What is your interest today? Please select from the following:
computer science
data science
web development
psychology
biology
social media
etc.
After the user selects their interest, the browser should allow the user to search or study only those selected content types, so the user cannot get diverted from their task. The purpose of this browser is to avoid time-wasting. Because whenever someone tries to study or do some professional work, they get diverted by opening social media tabs and movies.
Which programming language will be suitable for making this browser?
You could do this by making a custom version of an existing browser, as guest271314 suggested, but that would require far more effort than necessary. All you need to make is a browser extension, such as a Firefox Add-on or a Chrome Extension. Browser extensions are usually written with JavaScript, HTML, and CSS. Each browser needs to have an extension made individually, but you can usually share a lot of the code between them. Read the linked documentation for help creating an extension for each browser.
There are already existing browser extensions like you describe that prevent you from visiting sites that you put on a list ahead of time, such as StayFocusd and WasteNoTime. Maybe you just want to use one of those extensions instead of writing a new one.
We have a .Net application that is used for editing/rendering customized HTML documents. It is hosted in IE using the AxSHDocVw.AxWebBrowser controls. We proceed with navigating to "about:blank" page initially then we change the Document by writing our custom values into it. The problem we are facing is the call to IHTMLTxtRange.execCommand("Copy",false,null) is failing if we don't enable the IE Security Settings in the Internet Security zone (Scripting->Allow Programmatic Access to Clipboard ).
In order to bypass the security setting ,I tried to point to a local html file initially while navigating. But this fails as soon as I modify the Document.
I want to use the IHTMLTxtRange.execCommand("Copy",false,null) command so that I can customize our Copy/Paste operations.
Is there any other way I can do this.
Please share your ideas inorder to overcome this situation.
Thanks.
Sriram
Try implement IInternetSecurityManager on your webbrowser control host, handle URLACTION_SCRIPT_PASTE in ProcessUrlAction.
Note there is a bug in earlier versions of IE that causes the webbrowser to ignore host's URLACTION_SCRIPT_PASTE handling.
As far as I know, there is no way to do that without user permission. Its a security/privacy loophole to allow access to clipboard, and its natural that browsers are protective about it.
You have already tried out ActiveX, and it doesn't work
With Flash, you can interact with system clipboard - but only if its a part of an event handler. See Flash Player 10 Security.
Javascript doesn't expose a way to access the clipboard.
Not sure about silverlight, but I am guessing it would also restrict access to clipboard.
In short, the user has to explicitly give your application/website permission to access clipboard.
Question: Is it possible to construct a web page that has a script to turn off XML data-binding in MSIE? The ideal approach would be to code an HTML page and instruct all people in the office to visit the page with a button that says "turn off data-binding".
Rationale: The desktop sysadmin is not available at this time and the goal is to create a brain-dead simple way to let people turn this feature off without having to walk them through a bunch of MSIE configuration menus.
I'm assuming you're talking about Microsoft Security Advisory (961051).
If you could disable XML data-binding using client-side script, then someone could enable it with client-side script and expose the vulnerability again. So that isn't possible.
However, if everyone is running the same version of Windows and the same bitness flavor, then just send them to a page where they can copy and paste this into Start > Run:
Regsvr32.exe /u "Program Files\Common Files\System\Ole DB\oledb32.dll"
Note that this will protect against current attacks but to comprehensively protect against the vulnerability they recommend applying another workaround. More on that here.
And encouraging your employees to go to a website in an E-mail and run something they've been told to run is probably a bad idea as it opens them up to various phishing attacks since most people won't be able to distinguish between an E-mail from their own company IT department and an E-mail sent by a malicious person.
More about the available workarounds here.
In the end, the best practice would be to push out one of the workarounds as described in the above KB article.
I know this might be a no-brainer, but please read on.
I also know it's generally not considered a good idea, maybe the worst, to let a browser run and interact with local apps, even in an intranet context.
We use Citrix for home-office, and people really like it. Now, they would like the same kind of environment at work, a nice page where every important application/document/folder is nicely arranged and classified in an orderly fashion. These folks are not particularly tech savvy; I don't even consider thinking that they could understand the difference between remote delivered applications and local ones.
So, I've been asked if it's possible. Of course, it is, with IE's good ol' ActiveX controls. And I even made a working prototype (that's where it hurts).
But now, I doubt. Isn't it madness to allow such 'dangerous' ActiveX controls, even in the 'local intranet' zone? People will use the same browser to surf the web, can I fully trust IE? Isn't there a risk that Microsoft would just disable those controls in future updates/versions? What if a website, or any kind of malware, just put another site on the trust list? With that extent of control, you could as well uninstall every protection and just run amok 'till you got hanged by the IT dept.
I'm about to confront my superiors with the fact that, even if they saw it is doable, it would be a very bad thing. So I'm desperately in need of good and strong arguments, because "let's don't" won't do it.
Of course, if there is nothing to be scared of, that'll be nice too. But I strongly doubt that.
We use Citrix for home-office, and people really like it. Now, they would like the same kind of environment at work, a nice page where every important application/document/folder is nicely arranged and classified in an orderly fashion
I haven't used Citrix very many times, but what's it got to do with executing local applications? I don't see how "People like Citrix" and "browser executing local applications" relate at all?
If the people are accessing your Citrix server from home, and want the same experience in the office, then buy a cheap PC, and run the exact same Citrix software they run on their home computers. Put this computer in the corner and tell them to go use it. They'll be overjoyed.
Isn't it madness to allow such 'dangerous' ActiveX controls, even in the 'local intranet' zone ? People will use the same browser to surf the web, can I fully trust IE ?
Put it this way. IE has built-in support for AX controls. It uses it's security mechanisms to prevent them from running unless in a trusted site. By default, no sites are trusted at all.
If you use IE at all then you're putting yourself at the mercy of these security mechanisms. Whether or not you tell it to trust the local intranet is beside the point, and isn't going to affect the operation of any other zones.
The good old security holes that require you to reboot your computer every few weeks when MS issues a patch will continue to exist and cause problems, regardless of whether you allow ActiveX in your local intranet.
Isn't there a risk that Microsoft would just disable those controls in future updates / versions ?
Since XP-SP2, Microsoft has been making it increasingly difficult to use ActiveX controls. I don't know how many scary looking warning messages and "This might destroy your computer" dialogs you have to click through these days to get them to run, but it's quite a few. This will only get worse over time.
Microsoft is walking a fine line. On one hand, they regularly send ActiveX killbits with Windows Update to remove/disable applications that have been misbehaving. On the other hand, the latest version of Sharepoint 2007 (can't speak for earlier versions) allows for Office documents to be opened by clicking a link in the browser, and edited in the local application. When the edit is finished, the changes are transmitted back to the server and the webpage (generally) is refreshed. This is only an IE thing, as Firefox will throw up an error message.
I can see the logic behind it, though. Until Microsoft gets all of their apps 'in the cloud', there are cases that need to bridge the gap between the old client-side apps and a more web-centric business environment. While there is likely a non-web workaround, more and more information workers have come to expect that a large portion of their work will be done in a browser. Anything that makes the integration with the desktop easier is not going to be opposed by anyone except the sysadmins.
The standard citrix homepage (or how we use it) is a simple web page with program icons. Click on it, and the application get's delivered to you. People want the same thing, at work, with their applications/folders/documents. And because I'm a web developer, and they asked me, I do it with a web page... Perhaps I should pass the whole thing over to the VB guy..
Ahh... I know of 2 ways to accomplish this:
You can embed internet explorer into an application, and hook into it and intercept certain kinds of URL's and so on
I saw this done a few years ago - a telephony application embedded internet explorer in itself, and loaded some specially formatted webpages.
In the webpage there was this:
Call John Smith
Normally this would be a broken URL, but when the user clicked on this link, the application containing the embedded IE got notified, and proceeded to execute it's own custom code to dial the number from the URL.
You could get your VB guy to write an application which basically just wraps IE, and has handlers for executing applications. You could then code normal webpages with links to just open applications, and the VB app would launch them. This allows you to write your own security stuff (like, only launch applications in a preset list, or so on) into the VB app, and because VB is launching them, not IE, none of the IE security issues will be involved.
The second way is with browser plug-ins.
For example, skype comes with a Firefox plug-in, which looks for phone-numbers in web-pages, and attaches special links to them. When you click on these links it invokes skype - you could conceivably do something similar for launching your citrix apps.
You'd then be tied to firefox though. Writing plugins for IE is much harder than for FF, I wouldn't go down that path unless forced to.
I want to allow my users to embed their own Flash animations in their posts. Usually the actual file is hosted on some free image hosting site. I wouldn't actually load the flash unless the user clicked a button to play (so that nothing auto-plays on page load). I know people can make some really annoying crap in flash, but I can't find any information about potential serious damage a flash app could cause to the viewer.
Is it unsafe to embed just any flash file from the internets? If so, how can I let users embed innocent animations but still keep out the harmful apps?
edit:
From what I can gather, the most obvious threat is for actionscript to redirect you to a malicious site.
Adobe says you can set allowScriptAccess=never and allowNetworking=none and the swf should have no access to anything outside of itself. Will this solve all my problems?
Flash has some neat security measures in place. Allowing users to upload swf's to your site and embedding them is unsafe, you're basically setting yourself up for an XSS attack.
However, allowing them to hotlink should not be a problem. The swf will be locked to the domain that is hosting it and is not allowed calling url's outside of that space.
It will still be open to "evil links" (i'm sure theres a proper word for them), and by that I mean having regular links to yoursite.com/admin/deleteallpages.php which it tries to load "as" you. It will not however be able to use this data in any way, it'll basically be the same as a normal link, and I'd guess modern cms' are protected from that type of attacks.
You could get the same protection by hosting your flashes on a different subdomain, since flash considers this the same as a completely different domain.
When embedding SWFs from unknown sources, it is also best practice to throw a mask on the Loader so that the loaded SWF can't take over more screen real estate than expected.
Pseudo-code to do so:
var maskSpr : Sprite = new Sprite();
maskSpr.graphics.beginFill();
maskSpr.graphics.drawRect(0,0,safeWidth,safeHeight);
maskSpr.graphics.endFill();
myLdr.mask = maskSpr;
There is actually more than one option.
To be totally safe, set allowScriptAccess=never and allowNetworking=none and the swf will have no access to anything outside of itself.
NOTE: allowNetworking is only in Flash Player 9 (it was created in response to various myspace worms), so you'll need to use SWF Object to insure that only users with the right flash player version or better have the flash loaded.
If you want to enable things like youtube videos, though, you can't set allowNetworking to "none". Fortunately, there is an intermediate level of security for this field - "internal" which lets the SWF talk to its hosted domain.
Also note that you better not have a crossdomain.xml file on your site - read more about those dangers here and other places.
Here are some other sites that are mentioned by other answers that go into more detail:
http://www.adobe.com/devnet/flashplayer/articles/secure_swf_apps_04.html
http://blogs.adobe.com/stateofsecurity/2007/07/how_to_restrict_swf_content_fr_1.html
As an example Drupal has a scenario of how allowing flash content from users could be a security concern.
Adobe says you can set allowScriptAccess=never and allowNetworking=none and the swf should have no access to anything outside of itself. Although allowNetworking is only in Flash Player 9, so users with earlier versions of Flash would still be susceptible to some exploits.
Creating more secure SWF web applications : Security Controls Within the HTML Code
How to restrict SWF content from HTML
Yes, it's unsafe.
There's no easy way of allowing it. You could have a domain whitelist that allowed YouTube, Hulu, etc. through, but whitelisting is inherently painstaking - you'd be constantly updating.