I am creating an application that is transmitting images but the way basic javascript works the images can potentially be downloaded straight from the console in JS. I wanted to know if there is a solution for transmitting images that can't be downloaded from the console. I have seen topics about encrypted media extensions that are used by such as netflix. Is this a solution for what I have described? If so how do you use it with a library such as React?
I don't know if it's appropriate to answer this way, but there is not a true way of preventing images from being downloaded from the browser. For the user to see an image served by your website, it has to be loaded into the browser's memory. While there are tricks to prevent a simple right-click and "Save," your question is asking if it's possible to prevent transmitted images from being saved via console (or in general, it seems). The answer to that is "no", since its presence in memory opens it up to all manner of copying it. Could be a simple screenshot or getting it from the dev tools sources tab or via console script.
Related
We are currently looking at porting a enterprise silverlight application over to html5. The major roadblock that we have hit is the ability to open files from the user's local disk. Currently they have a document library which just links to files on their computer that they can open from within the app and view or print out. All that I read is that you can only access the local sandbox of the web app with the html5 file api's. We want to load these files from code.
Does anyone know of any workarounds to this?
Thanks
There is no way for html5 to access local file without user selection. But FSO: FileSystemObject works for IE and MAYBE could be regarded as a work around. But still there are some requirements to meet.
It is possible to use chrome's filesystem API to access files on a users local filesytem. So you'd have to be willing to make this a chrome only application.
Using java you can create a "Signed" applet which has access to the local filesystem. (if the applet is signed you can request filesystm permissions)
then there is a tutorial for accessing methods of your java code directly from javascript here: http://docs.oracle.com/javase/tutorial/deployment/applet/invokingAppletMethodsFromJavaScript.html
you should be able to perform something similar from silverlight.
There is no workaround in pure HTML5/Javascript. You need the use of plugins, such as Java or Silverlight (maybe you shouldn't port it after all). As for workarounds, HTML5 gives you an easy way drag and drop multiple files that you could transfer on the server and then display back to your users. Another workaround would be to install a custom agent (a software with only a tray icon) that would send the information about the current user "document library" to server and then again, you could display it back to the user.
Note: I've heard somewhere that browsers will eventually stop supporting plugins. http://www.howtogeek.com/179213/why-browser-plug-ins-are-going-away-and-whats-replacing-them/
Ya, I agree with Markain. However, if you were to limit your audience solely to chrome users, I daresay, you would most likely use some of your users. If Huazhihao is right, then your number of leaving customers should decrease but users who regularly use firefox won't be happy. Overall, I think that this will not work. Otherwise, there would be too many websites that trashed your hard driver (or at least wherever you have the rights to edit/delete files). I think it would be best if your product was setup to synchronize the file whenever an internet connection was detected and a change was made to the file. That way the user would not need to visit the website whenever the file was uploaded. If this is some kind of an error file, then it would be most beneficial if you were to make a link in the application that when clicked, would upload the file to the website and the website were to do whatever was necessary. If this is a purely online thing, then I don't see what business you would have looking through other peoples' files =-). Hope I helped!
I have a program where the user does some actions (i.e. clicking on several buttons). I want to record their clicks and the buttons that they click to allow the user to then download a text file with a record of their clicks when they click a separate "download" button. I looked at the File-system APIs for HTML 5, but they seemed to not have cross-browser support. I would ideally like to have this entire file generation and download scheme be entirely client-side, but I am open to server-side ideas as well.
TL;DR: Essentially I'm looking for an equivalent to Java's FileWriter, FileReader, ObjectOutputStream, and ObjectInputStream within Vanilla JS or jQuery (would like to stay away from php, but I'll use it as a last option).
Also, why don't all browsers support the filesystem api? (I'm guessing that it would make MSWord and Pages go out of business with all the open source clientside text editors that could come out.)
Unfortunately the HTML5-File-system is no longer a part of the spec, long story short FF refused to implement because they claimed everything you could do in the File-System API was doable in the HTML5 Indexeddb (which was mostly true). Please see this blog post for more on why FF didn't implement. I do not know IE's story. (I may have exagerated why FireFox didn't implement, I'm still bummed because you cannot actually do everything in indexeddb that you can do in the noew "Chrome File-system API")
Typically if two of those three browsers implement a spec, it stays in the spec. Otherwise that spec gets orphaned. However, I'm fairly certain a large reason the file-system api didn't take off is because of the IndexedDB API (caniuse IndexedDB) really took off when both specs were introduced. If you want cross browser support, check this api out.
That all said if you are still set on the file-system api some developers wrote a nice wrapper around the IndexedDB, the File-system api wouldn't actually supply you with a stream anyway. You would have to keep appending events to a given file given a fileWriter object. you'd then have to read the entire file and send to the server via an ajax request and then downloaded from the server once successfully uploaded.
The better route would be to use the IndexedDB apiwhich as stated on developer.mozilla
Open a database.
Create an object store in upgrading database.
Start a transaction and make a request to do some database operation, like adding or retrieving data.
Wait for the operation to complete by listening to the right kind of DOM event.
Do something
with the results (which can be found on the request object).
Here are a couple tutorials on the IndexedDB.
https://developer.mozilla.org/en-US/docs/Web/API/IndexedDB_API/Using_IndexedDB
http://www.html5rocks.com/en/tutorials/indexeddb/todo/
As for giving the user that file, as mentioned briefly before you would have to upload the file to the server and download upon the "download" request. Unfortunately you have to trick the user into giving them the data already on their machine. Anyway, hope this all helps.
I have created a webpage but my friends or collegues always copy the source code and copy all the data easily, so is there any way to hide page source option from browser ?
As a rule, if you are putting information on another user's computer (whether because you made a document or they viewed your webpage), you really can't control what they do with it.
This is an issue that larger companies deal with often. Have you heard of DRM? It's a mechanism that companies like to try to use to control how people can connect to their services, use their content and in general, try to exert control over their data while it's on your system.
Now, a web page is a relatively simple container for holding information. You expressed an urge to prevent your friends from copying the source code. You could try to encrypt it, but if it's using local data to decrypt itself, there still isn't going to be anything that stops them from just copying what's in the View Source window and running it again (even if they can't really read it).
I'd suggest that you don't worry about it. If what you have on your page is so important that others shouldn't be able to see it, don't put it on a webpage.
Finally, Google doesn't much care that you're able to view the source to their home page. Why not? Because the value of the search engine isn't in what the home page looks like, but in the data on the back-end that you don't have direct access to. The value is in the algorithms that execute on the server when you hit that Google Search button that queries that data and returns the information you're looking for. There's very little relative value in the generated HTML that you see in the page. Take a leaf from their book and don't stress that they copy your HTML.
No , there isnt any way to do it, however you can disable right clicking in browser via javascript, but still they can use shortkeys to open developer view (in chrome F12) and see the source. You cannot hide html or javascript from client, but maybe you can make it harder to read.
No. Your HTML output is in the user's realm. Even if there was a way to disable view source in one client, a user could use a different one
Always assume that your site's HTML is fully available to end users.
Yes and no. You can definitely make HTML and JS harder to intrepret by obfuscating your code - that is, taking your code and making it look confusing. Here is a tool that can do that: http://www.colddata.com/developers/online_tools/obfuscator.shtml
However, these things all use code, and code can be decrypted through any number of methods. If you post a song to the internet, even if they cannot find the mp3, they can simply record their speakers. If you upload an image and prevent users from downloading it, they can take a screenshot or use their camera. In order for HTML and Javascript to work, it has to be intrepreted by their computer, and even if you do find a way to disable "View Source" there are others ways, like a DOM inspector (F12 in IE/Chrome, Ctrl+Shift+K in Firefox).
As a workaround, use copyright, warn your users they will be punished if they copy your code, and put watermarks, labels and logos over any mp3s or images you don't want stolen. In the end, disabling right clicking (which is also possible, see How do I disable right click on my web page? ) or disabling selection (also possible) does nothing, because there is more than one way to get your code, like searching through temporary internet files.
However, you ask "what if I want a site where my users can log in and I need security? How can I make it so nobody can see my code then? Doesn't it have to be secure and not out in the open?"
And the answer is, yes, it needs to be secure. That's what server-side languages, like PHP, are for. PHP does all the work on the server itself so the user cannot see it. PHP is like a pre-rendered language - rather than doing it in real-time, PHP does all the work beforehand so the user's computer doesn't have to, making the code safe. The code is never put onto the user's computer, because the user's computer doesn't need it. The work is done by the website itself before the page is sent. SSL is often paired with PHP to make absolutely sure that websites have not been hacked.
But HTML and Javascript have to be done in real time on the user's computer, so you cannot disable View Source because it is useless. There are many, many ways that users could get around it, even if View Source is disabled, and even if right clicking is disabled.
If your code doesn't need to be secure, however, I'd recommend you consider keeping it open source. :)
I'm creating a personal home page, due to the fact that iGoogle will be discontinued. One of the things I'm trying to create, is a speed dial-type interface, with website thumbnails as links, and I'd like to automate this process.
I've attempted screenshot automation a few years back with linux and the webkit engine. And it's fine. But my problem is, that I want the screenshots to be from my browser, i.e. my Gmail inbox, not the login page I'd get if attempting a remote screenshot.
I thought of using html2canvas but again, I'd have to load the source of the webpages remotely using a proxy, and that's not what I want. Another attempt of mine, was to load the website in an iframe, extract the source, and pass it on to html2canvas. Unfortunately most websites like google, facebook etc don't allow embeding their websites into iframes, so I'm still stuck.
How do plugins like FoxTab, and SpeedDial make the screenshots from within the browser without popups etc? They do it "browser side" silently, is it possible to duplicate this using just JavaScript? Or is there a way I could accomplish the same in another way, perhaps with a custom addon or something?..
Have you considered using a service like http://webthumbnail.org/ ?
http://phantomjs.org/ is also a great service for that if you want to do it yourself.
Take a look at phatomjs. We use it to take screenshots of all our hosted sites periodically. Phantomjs is a headless Webkit implementation.
I want to allow a web site users to be able to download files from my site, but with the help of a client-side downloader with an ability to continue an interrupted download.
For example, I want to sent a person a file with a size of 30+ Meg. I want the user to have the best downloading experience, so I can't afford him downloading 25 Meg and then getting the download dropped due to the network problems on his side.
Therefore, I want to have a javascript downloader rendered on a download page, that will show the actual client-side file delivery, and when it is downloaded, to give an ability to a user to save the file.
Or is it not possible due to the fact that javascript won't be able to open a save file dialog and save to a file system?
I'm afraid that is not possible with JavaScript and that's why:
To continue downloading from the certain point you should send to the server the position number to start downloading from. And as JavaScript has no access to local file system, you can't get that position.
UPD: it seems that I was too hurrying with the reply.
The file size can be gotten using the HTML5 File API and after getting the file size you can pass it to the server which should support the partial downloading.
But anyway, after downloading another part of the file you should sew two pieces together in some way; standard web browser dialog will only suggest to overwrite the file.
UPD2: to work with files in some Internet Explorers you can use FileSystemObject:
var fso;
fso = new ActiveXObject("Scripting.FileSystemObject");
I'd look into making a plugin or extension. Like those DownloadThemAll extensions for firefox and Google chrome. Another alternative would be to use Flash, either alone or integrating it with javascript like hinted here: http://www.communitymx.com/content/article.cfm?cid=0922A