I want to at least prevent normal users to download my flash video.
What's the best way to do it?
Create a httphandler, add a token (e.g. timeid), set the cache control to no-cache so that only the users with correct token can view the correct video. Is that feasible?
It is the requirement from client that the video should not be downloaded by users and should be watched only in the particular website.
I want to know if this works:
http://www.somesite.com/video.swf?time=1248319067
Server will generate a token(time in the above example) so that user can only have one request to this link. If the user wants to watch the video again, he needs to go to our website to get the token again. Is this okay to prevent novices from downloading?
I can't download this flash video by the downloadHelper firefox plugin:
http://news.bbc.co.uk/2/hi/americas/8164177.stm
Updated (13:49 pm 2009/07/23):
The above file can be downloaded using some video download software.
The video files of following Chinese sites are well protected (I can't download it using many video download software):
http://programme.tvb.com/drama/abrideforaride/video/
Do you know how it is done?
I dont think there is an easy way to stop people from getting your videos if they want them,
there are plenty of plugins for firefox that allow downloading from even youtube and many places. And i imagine those plugins would disable any attempt you made to hide your videos.
not too terribly different than taking an image from flicker, they put a clear gif image over the image that you want to view, so that when you right click and save you get "the shield" image, however can be defeated by the lowly print screen button.
if you want casual users from getting your file, use a flash control and buffer a minute or two of your videos and make that flash authenticate with the server to get those files. that seems reasonable to me
I don't think there really is an easy way to limit people from getting at it. Your sending them the video, that is how they are able to view it. Any user could just use FRAPS or a similar tool to copy the video from the screen as well.
If your worry is being copied and used elsewhere then you can watermark it or use a few other types of copy protection methods that will allow you to identify your work on other sites. If your worried about people copying it for personal use, then you really have no way of stopping it, you are sending it to them.
Edit: Due diligence would be to inform your customer of how easy it is to copy the work that they will be posting. Most clients have really no idea how easy it is.
This is how I like to tackle this issue.
This method works by creating a ticket to download the content over one http request...Another attempt to use the same ticket to download the content will fail, hence any extensions that attempt to download the content again or a user manually attempting to fail to do so, hence the flash player will be the only way to download the content. However there is one downfall for this approach, users will not be able to skip to a part of the video that has not been download...in some standard player implementation that may even stop the video from loading. Any ideas on this will be highly appreciated.
I begin by writing a PHP script that takes in a video_id, file_name, or a local path to your video file (Depending on the storage infrastructure of your video collection) in a GET request along with a unique hash value (a hard to guess and come up with probably generated with a secret key so it can be validated to be coming from our reciever (flash player), if the hacker send us a used hash or an invalid hash (does not satisfy our key), we will not send him the file). The PHP script then opens the video file and sends its content with the correct video mime type. for FLV the mime type is video/x-flv. It makes sure that once a unique hash has not been used before and is validly generated from your secret encryption key.
Then once the page with the flash player is loading we can give the .php file with the right get parameters as the video url to the video player. (If it is a prude player that only allows flv files you can always program your .htaccess file to parse .flv files as php script in the specific folder only, and rename your .php file as .flv and try your luck)...anyways...Also generate a hash key...perhaps you can take the servers current time and append it to a salt value such as another key known by both scripts, and encrypt this final concatenation with your secret key.
So once the video gateway php script will recieve a filename or hash key...it will decrypt the hash key and figure out if it is validly generated from teh sister script, and make sure not to send the video again to the same hash key...
For added security you can perhaps reset the secret key everyday using either a cronjob or bootstrap mechanism. To prevent duplicate use of hashkeys you can store them in a mysql database, file operations, or NOSQL (depending on your needs and infrastructure).
Make sure that the file is requested by the same user agent the hash key was generated for. In case the hacker trys to cURL or Wget your videos unused url before the flash player gets a chance to consume the hash key. In this case the hacker will have to imitate the browser's user agent or download the file using their command line tool as well...However please note that this is not your average champ.
It sounds like you need to add authorization and authentication.
You could put the flash video under a different folder in your ASP.Net application and add a web.config file in that folder to deny access to unauthorized users. For example:
Then you need to enable authentication for your website. The simplest method is forms authentication. A trivial example with hard coded username and password is provided here.
There is loads that you can do with the authentication framework in ASP.Net I suggest googling a bit.
The only way to do this is with a trusted client, DRM and an encrypted source.
Your player opens up a connection, the user has a connection to the stream, you perform some magic authentication with their token and then transmite the encrypted data to them.
If you don't do this then anyone can download your video and save it out.
However with all that aside, someone can run screen capture, then save your video and do it again. This is again where the DRM comes in as one of the key features of the DRM in windows clients is that the buffer cannot be sniffed as it's on the protected media pathway.
I guess its a question of how to protect your revenue but dealing with pirates is always going to be a problem for software devs no matter what their business is.
I have a solution that i'm gonna try for myself (as I have the same worries) but I know that it includes a lot of extra time and work...
Solution: using flash compress the video into an swf file. Before compressing add some AS code to the movie for authentication. suggestions for authentication:
1 test url
2 create a dedicated flash player that has handshake code checked by the video.swf
I like #2 better, and as an extra measure, you can overlay an id code over the video, so if someone captures the video using screen recording software, you'd at least be able to track the original source of the copied video.. and exact suitable retribution...
Simply you can't prevent it.
But..you can make it difficult.
Here some ideas come in my mind
1 First of all add your identifier to the video (always someone can download it)
2 The hard way... Add Ajax call back to server to check a random generated key that it will stored in the session every N seconds. After every post back clear the buffer of the player and start the video from were i was (using javascript).
Use again JavaScript prevent the video source from downloading by "view source".
3 Handle all your videos in urls like http://www.example.com/viewvideo/1 OR ../?id=1.
Add blank image overlay with transparent background.
Serve the original video and a blank video somewhere on the page with normal extension and style attribute "display:none". (will create problems to some download helpers)
4 Everytime you serve a video CHECK if the request is from a browser (ie check UserAgent)
5 Cookie with some random value combined with the id of the video. Check it client-side and server side and then serve the video.
6 On focusout event hide the video with javascript. put a resume button in the flash and leave the frame unchange (like pause but with no original video in buffer).
7 Combine those methods
these are random generated ideas,
not tested neither i say that guaranties no video downloading.
I have attempted two way to prevent the downloading but fails.
Using javascript to dynamically generate the object for flash.
Using the token idea proposed in the question.
What annoying me most is that a simple SAVE/AS from the firefox browser could easily bypass the tricks.
The only variable way so far is to using an empty swf file to load another swf file in. Combined with the token idea, it works.
in my answer you cant stop image/video theft but you can make harder for normal users but you can't make it harder for the programmers like us( i mean thiefs that knows little web programming) there are some tricks you can try:-
1.) Using flash as youtube and many others sites like http://www.funnenjoy.com does .
2.) Div overlaping or background pic setting (but users with little sense can easily save all resources by opening inspect element or other developer option).
3.) You can disable right click and specific keys like CTRL + S and others possibles with JAVASCRIPT but main drawback is that if user disable JAVASCRIPT our all tricks fail down.
4.)Save image in none online directories(if you have full access to web server) and read that files with server side languages like PHP every time when image / video is required and change image id time to time or create script that can automatically change ID after every access.
5.)Use .htaccess in apache to prevent linking of your images by others sites. you can use this site to automatically generate .htacess http://www.htaccesstools.com/hotlink-protection/
Related
Abstract: There is a page with a player that loads audio file and plays it. The player used on the web page is jwplayer. I need to find a way to determine if the audio file is being streamed to the player or not.
Background: In my research I found that if I use nginx header like X-Accel-Redirect - the file will be streamed. I have setup the web server with nginx + apache combination (nginx is reverse proxy for apache), after that I pointed jwplayer to the mp3 file - and it is working. I mean I am able to click anywhere on the audio timeline and it immediately starts playing sound. But, since I didn't set that header yet, and adding the fact that player already works - that's why I need to check my question and know for sure.
Some of my own thoughts: JwPlayer itself supports some kind of bufferring, so I have no idea whether it just downloads the mp3 file I am testing this functions on, or it receives the stream and plays it out.
Is there a way to check and know for sure? The only idea about all of this I have is to check access logs, but I don't know what to look for, or if I need a special format for the logs to see those requried data.
While I was researching the issue I got some weird download related topics and something about HTTP headers with "Ranges" in them, but I am not sure that it relates to the streaming or not.
Please advice.
From the point of view of the server, there is no difference between download and streaming. A server just send bits. What happens to those bits later is unknown. What you need is a player that sends reports to back to the server or a loging service such as mixpanel.
This is both a strategy and a technical question, I'm building a web posting mechanism and I will need to store a lot of HTML posts (discussions, comments etc.)
I'm thinking about saving all my HTML posts into database as a ZIP compressed stream (instead of plain text or XML) in order to save space and increase security by encrypting those ZIP data steams, so it will be saved to the database compressed (hopefully close to 90% smaller) and secure. (it does not need to be searchable, I'm going to create the search index myself out of the content of each post)
I want to deliver the ZIP object to the web page/cache and then have the client side unzip the stream and render the HTML that it represent.
This is a Microsoft based MVC web site (c#)
I'm trying to figure out reasons not to do it... other than performance, can anyone pinpoint any other issues with doing something like that?
Also, is there any recommended libraries or built-in ones that I should use for better performance - that both server side and client side can understand (zip and unzip with encryption key/password)?
Thanks in advance.
In normal operation, http allows to send the html in a gzipped stream. The webserver compresses the data and sets the corresponding header. The client then unzips transparently.
You simply have to make sure to set the correct header and not have the webserver zip again the already zipped stream.
I see a major drawbacks :
You cannot alter the data. That means you cannot add the code for your template nor link between the pages.
I don't think this is a good approach. Store your data as you like and decompress it on the server.
Other than HTTP PUT and POST, what other methods can a web application designer use to allow users to upload content (either files or listbox text) from a page of his web app to a remote server?
On the same topic, I was wondering what technology/APIs does a service like Google Docs or Google Drive use? The reason I ask this is: Our Sys Admin has disabled file uploading (via Squid proxy), yet I was able to create and share a document using Google Docs / Google Drive.
Many thanks in advance,
/HS
EDIT Please see the strikeout above.
This depends on the server in question - as the standard set of HTTP commands can be expanded, and some may not be configured/allowed. One of the common commands is "OPTIONS" that ask "what can I do".
But to answer more helpfully: you generally have two main options:
POST (the one you probably want to user as it's nearly always avaiable
GET. You could use GET (but I'm NOT advocating it - just saying you could you it - you should not use a GET to make changes to the server). There are problems with this approach (including size of files, manually handling the encoding etc) but it's possible if you have to go this route.
PUT it often not enabled on servers for security reasons.
More reading: http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html
Edit: if "file uploading" is prevented by proxy, have you tried encoding the POST? i.e. As opposed to sending a multipart POST, try encoding the files yourself into POST string and sending that instead? Or encode the file and split into multiple small posts and piecing them together at the other end?
Google Docs uses a mixture of POST and GET. POST for the updates. Google Drive I don't know.
I am embedding tracking images within emails that are being sent from a custom-built opt-in CRM system. The image src is an encoded .gif, such as src="12_34_675.gif". The image is served by an ASP.NET httphandler that decodes the src encoding and serves a transparent image.
Everything works fine, but some email clients request the image multiple times, creating duplicate entries. Some clients make three calls all within one second, and some seem to make tens of calls over a day or so. Mostly email clients make single calls, but these few duplicates are very perplexing. I know I can code around them, but I'd really like to understand what's going on.
I've checked the IIS log files, which show that the duplicate requests are coming from the client machines. I can't think what might be causing these duplicate http requests.
Help!
I don't think this is something you can control. What if they have an old version of outlook open (older version used to open images embedded in message by default, nice) with the preview pane and pass through your email a few time.
I am sure you are not using the tracking data directly from urchin or whatever you are using. Is there a reason the duplicate log entries for the image are a problem?
I actually have this same problem now and I'm not sure why.
in my code I redirect using mod_rewrite to a tracking script and this script basically parses the get params for which campaign and which contact list etc, then I write some data to the database.
at the end of the script, I output the image using code like
header("Content-Type: image/jpeg");
readfile($filename);
$filename is the correct file, I checked it, var_dump'd it and the script does output the correct file.
in my access logs, I get TWO hits on the script, I get TWO duplicate records in the database and all my stats are double what they should be.
The closest example I can think of is iTunes. I'm thinking about a system where a server stores loads of files, and each user only has access to those they have paid for. Using a desktop app, they can download these to their local PC where they are stored as regular files.
How might one approach this? I can see a couple of possible options, and have some initial thoughts, but would welcome feedback on these or other ideas. If you post your preferred design, people can vote on them!
1)Use HTTP requests, and the response is the file data. Then a simple servlet (or similar) can act as a control on which files are downloaded.
PROs: easy to do
CONs: seems a little hacky, how would you display a progress bar?
2)Use sockets, and a custom server app which pipes data to the server
PROs: Perhaps more performant (?), can send data in nice sized chunks
CONs: A little more work on the client side, quite a bit more to write a custom server-side app that runs 24/7
Thanks in advance. Someone please edit my tags, I can't think of the right ones!
Use HTTP requests, and the response is the file data. Then a simple servlet (or similar) can act as a control on which files are downloaded. PROs: easy to do CONs: seems a little hacky, how would you display a progress bar?
I don't see why this is hacky? Your App would authenticate using the user's user name and password (if you want it to work like iTunes) and fetch files according to permission level. A progress bar is easy to do because you will get the content-length header in the response. It's a more flexible approach than FTP - but if FTP already does everything you need, go for that.
As said, FTP is what you need. To control per user, per file permissions you can create one system user and then you can apply filesystem level ACLs. Then, a FTP server like PureFTPd will let you login with system accounts with the specified permissions.