Read-only access to file:///var/mobile/Media/DCIM/ with Codename One - codenameone

I need to check if a given permission (access to gallery on iOS) is granted, before executing a portion of code, but I did’t find what API to use. Can you help me?
My use case is to list the content of file:///var/mobile/Media/DCIM/ directory (in particular accessing to the “APPLExxx” subdirectories) using the FileSystemStorage API, but my code fails. I suppose that I need the gallery permissions, but I don’t know how to check/require them. Thank you
Underground problem: I wrote a native interface to access the gallery content, but I hate my native code, it’s a mess and it’s bugged/unusable, that why I trying to do the same task using a simpler cleaner approach, that is to try to access to the “dcim” directory with an high level API like FileSystemStorage. I only need to read the content (photos and videos), I don’t need to write (I know that I cannot write in that directory without low level APIs).
Thank you for suggestions and code examples.

Related

Will CodenameOne ever support saving images and / or files to a place users can access outside the app?

I've read a few threads where this is discussed. Shai's response has always been that files can only be read, but not written into shared locations
Perhaps saving other type of files isn't so simple but shouldn't there be an option for saving pictures in CN1?
I haven't seen the Whatsapp Clone code, but if it truly is a clone shouldn't it have the option to share pictures (and possibly files). Or is it a simple text chat that perhaps shares pictures that can never be saved outside the app?
I also read somewhere (6 months ago) that Shai said that this should be a feature of CameraKit. Does this mean that this feature is in development? If so, that would be great. But having an ETA would also be great to align with our own devs
If it isn't being developed, can I at least know if this is something I can develop natively within CN1?
We expose the full file system so you can write to any place the native App can write to. Native apps don't have write access to the gallery directory and need to explicitly request it to put a file there. This can be accomplished easily in any external cn1lib (e.g. we could do it in camera kit) but haven't done it for camera kit or the whatsapp clone.
AFAIK there's no RFE open on this feature so I can't even tell you if it's assigned to a specific milestone.

Protecting the video files from access by third party apps from iOS sandbox

I have a requirement where my app records the video files and stores them in app's documents directory. I want no other app should access these files other that my app. I have set file sharing enabled to NO. But I see some apps like iExplorer can show the video files saved under my app's documents directory. Can I know how this can be avoided.
I have also heard that by mounting the iOS device disk to any unix/linux machine can list out all the contents of the app sandbox.
So I want to know how to prevent this happening.
I tried with adding NSFileProtectionComplete as a attribute when saving the file. But this didn't solve the problem. Please help me on this.
Thanks,
I realize this is a little old but in the hopes of helping the next person who stumbles upon this:
You're probably looking for an encryption solution, combined with the standard steps for hiding your app documents folder as you've mentioned. Encryption won't necessarily hide the files but it will make them unreadable.
NSFileProtectionComplete only encrypts files when the device is locked. See the App Programming Guide for iOS section Protecting Data Using On-Disk Encryption. Also, keep in mind that when testing this, you'll have to wait 10-20 seconds after the device is locked before trying to verify that the file is inaccessible. If you want the encryption to persist past that point you'll have to handle it yourself. Something along what's described in this SO post perhaps.

Processing.js - Listing files from sketch directory

I'm new here, so hello everyone!
I wrote a few things in Processing language and now I need to switch to Processing.js. I need to write an app that first scans the sketch folder to prepare a list of provided files. And what was straightforward in Processing is not in PJS.
I'm currently searching the web but I only found solutions for classic Processing. I know that JavaScript has restrictions and in general can't access the user-side files, but is there any way to list the sketch-itself files?
The only way that comes to my mind is to list them on server side via PHP and generate the .pde file dynamically depending on the sketch folder. But the catch is to not use any other language.
Thanks in advance for help!
Processing.js running on a website can only get information that URLs can provide it, and since there are no "dir listings" on the web, it can't grab dir listing content for a URL for you work with. However, depending on what you really want to do, there might be a way to make it work without resorting to PHP.
Assuming you have your Pjs page running on www.example.org/index.html, and you want to list content for www.example.org/sketch/, one option is to simply have a file www.example.org/sketch/list.txt containing all the filenames that the sketch can access, and simply grab that with a
String[] fileNames = loadStrings("./sketch/list.txt")
instruction.
If you can give an example of what you mean with "I need to write an app that first scans the sketch folder to prepare a list of provided files", a more specific solution is probably possible (i.e., what are the files, what does the user need them for, etc)

I need help understanding Silverlight 4 security

Does anyone else think Silverlight 4 security is a bit screwball?
Look at the following scenario:
Silverlight when set to trusted app, and run out of browser mode allows you to browse for a file using the file open dialog.
You require the name of the path of the file to open it up from any COM automation. For example (excel/word) but this could be anything.
It is impossible to get the full path of the file from the dialog because of security restrictions
You can however using COM FileSystemObject - do what ever you want to the users file system, including create folders, move and delete files.
So in other words, why all the fuss about security in Silverlight, which actually hinders real business use cases, when its possible to access any file anyways using COM?
To say it another way, if a user runs a malicious silverlight app, its unlikely they'll say - oh well it was COM at fault. The COM was afterall being called by a Silverlight app.
Here is what I mean....
User browses for file - c:\myFile.xls
Silverlight prevents you from getting the path (for security reasons)
Silverlight only lets you work with my documents
Using COM you can do what ever you want to the file system in the background anyways. Including copying that file now to my documents, if only you knew the name! But besides that you can wipe any file potentially if its not in use.
In my opinion Silverlight security model is flawed, either they should have given developers full trust and allow us to run apps as if they were running locally
or
Not allowed Silverlight to access COM.
Is it just me, or can anyone else see that its a bad implementation?
This triggers security alerts:
OpenFileDialog flDialog = new OpenFileDialog();
FileInfo fs = flDialog.File;
string fileName = fs.FullName;
This doesn't
dynamic fileSystem = AutomationFactory.CreateObject("Scripting.FileSystemObject");
fileSystem.CopyFile(anyFileName,anyDestination);
I don't agree with your point of view. The fact that you can do pretty much anything that an installed COM object will allow you to do is not a reason to modify a whole bunch of existing Silverlight code to allow you to do those same things.
Why? Because in the process of opening up that code there is also an increase chance that in some unintended way that same code could get run when the Silverlight component is not running in trusted mode. If that were to happen even once the media would all over it in a shot and Silverlight's reputation would, probably unfairly, be in tatters.
Personally I'm quite happy with the very cautious approach to security that MS are taking with Silverlight.
some Silverlight controls such as the OpenFileDialog work in both trusted and untrusted mode. These controls have been ported from previous versions of Silverlight where the new levels are elevated trust were not a consideration.
Thank you to Anthony for pointing this out.
Developers need to be aware of the definition of trust we are discussing here. Running a Silverlight application in full trust with elevated privileges IS NOT the same thing as running a local Silverlight Windows based Application. It is also far more restrictive than ActiveX.
Its possible that the trust here provided in Silverlight suits your particular business requirement. It is however likely that there are scenarios where you will find Silverlight too restrictive, its best to do your research upfront, and run code samples to ensure you can do the critical stuff, before jumping in head over heels.
Microsoft guarantees that public Silverlight API has the same behavior for both for Windows and MacOS platforms. So the functionality is many ways limited by the common denominator and technical feasibility. Please treat COM introp as a specific case addressing only Windows platform and only in full trust mode and it is not going to work the same for other platforms. So the security restrictions are valid as they are the same for both worlds in terms of API reuse.
I agree with the original poster. I think it's bad implementation. We are given a built in dialog to browse for a file, including directory structure. We can select a file and get a FileInfo object, but security prevents us from getting the FullName (directory and file name). Why? How does that improve security? What's the point of the open file dialog to begin with?
And as the original poster mentioned, with those dynamic objects, we can modify the local file system... which seems like the possible security hole.
All I want to do is read some data from an excel file... a way for my users to import excel data into the application, and the file could be saved anywhere on their machine. These are sales reps using an excel files to record orders locally until they can get to an internet connection. Who knows where they all save that file... so I'm not going to try to suggest we tell them all to store it in the same place in "my documents". I'll get laughed at if I suggest that.
It seems like it should be incredibly simple. But that "security measure" that keeps us from getting the directory the user chose from the built in open file dialog makes it so that we can't use the dialog for the purpose it was created for.
So what's the alternative? Is there a way to pick files using those dynamic objects? Do I have to write my own file selection tool using those objects that can modify the file system? Since I don't need anything but to read the file, and because I read something somewhere that we do have access to the file stream... is there a way to using the file stream to open up the file for reading using the AutomationFactory?

Whats a good way to protect a link database from automatic scrapers?

I have a large link database, that I would want to protect against others who would want to copy them. Is there anything I can do other than force people to enter a CAPTCHA before each link?
you can output the links using ROT13, and then use javascript to put them back to normal.
this way, the scrapers must support javascript in order to steal your links, which should cut down on the number of eligible scrapers
bonus points: replace ROT13 with something harder, and obfuscate your 'decode' javascript.
The javascript suggestion could work, but you would render your page inaccessible to those using assistive technologies like screen readers as well as anyone without javascript.
Another possible option would be to generate a cryptographic nonce. This technique is currently used to protect against CSRF attacks, but could also be used to ensure that the scraper would have to request a page from your site before accessing a link. This approach may not be appropriate if you support hotlinking, but if you just want to make sure that someone went to your site first, it could work.
Another somewhat ghetto option would be use referrers. These can be easily faked, but it might prevent some of the dumber scrapers. This also requires that you know where your users came from before they hit your site.
Can you let us know if you are hotlinking or if the user comes to your site before going to the protected link? We might be able to provide better advice that way.

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