How to restrict folder access - ruby-on-rails

I have a rails app that writes to a file in my admins view folder. It creates a new folder for each user and a text file containing sensitive information.
How do i take the root folder and make sure no one can access the files inside?
/app/views/admin/NameOfFolder
NameOfFolder is the folder I want to protect that has sensitive data. The NameOfFolder is based on the user it is made for.

You don't have to. Nobody can access anything in /app. Only files in public are directly accessible to the Internet.
That said, it's highly wrong to use flat files for data storage, and especially to contain sensitive information. It's also extremely wrong to write arbitrary data files into /app/views. That directory is for your viwes, not for data storage.

Related

ASP.NET MVC How to display Image from folder outside webroot

Individual Folder create for each user when they register on website outside the webroot folder.I am able to upload the image and store Image path in database.However,I am unable to display the Image. I am trying to get the path of Image from database using LINQ and display in VIEW but it does not work. I can view only one(from the list of Image)Image when FILESTREAM the image path and retrun using FILESTREAMRESULT
Can anyone please guide me how to achieve it? All I want to do is create folder for each respective user when they register in external folder. Upload Image and display.
Typically, I would keep files in a secure database or within the application's subfolders. But, here's what I would suggest if you really need to access a different folder on the server.
Create a folder on your server's file system ahead of time.
On the server, assign permissions to that folder so that the identity used by your application can access it.
In your code, write code to access the folder and file path.
Hope that helps!
p.s. here's another Q&A on StackOverflow (with some words of warning) in which the second part of the answer is similar to what I suggested.
ASP.NET - Reading and writing to the file-system, outside the application

Rails File Upload - Scan files; and separate folders for each user

Does Paperclip scans the files for errors, malicious software, viruses before uploading to database? If no, what are the viable solutions.
And, is it better to first create a separate folder for each user before they upload files and store in their respective folders? What are the merits and demerits of it? Is it possible to specify this with Paperclip?
Thanks
Re viruses etc, this might be useful - Rails / Heroku - How to anti-virus scan uploaded file?
Re storing each user's files in a seperate folder: the conventional way would be to store every FILE in a separate folder, and then link the files to the user via the database (eg a user_id field on the file records). As far as merits and demerits go, besides it not being conventional, one thing to bear in mind would be that if a user's files are stored in a single folder, then if they upload a two files with the same name then the second would overwrite the first (unless of course you put them in separate folders within the user's folder). This could be a good thing or bad thing depending on your requirements.
BTW - a slightly pedantic note: files aren't uploaded to the database (at least not normally) - they are uploaded to a filesystem, and a corresponding record is created in the database. The files don't go into the database (as i say, usually: it is possible to store files as blobs in the DB but it's not good practise and not usual).

File repository in ruby on rails

I would like to create a simple file repository in Ruby on Rails. Users have their accounts, and after one logs in they can upload a file or download files previously uploaded.
The issue here is the security. Files should be safe and not available to anyone but the owners.
Where, in which folder, should I store the files, to make them as safe as possible?
Does it make sense, to rename the uploaded files, store the names in a database and restore them when needed? This might help avoid name conflicts, though I'm not sure if it's a good idea.
Should the files be stored all in one folder, or should they be somewhat divided?
rename the files, for one reason, because you have no way to know if today's file "test" is supposed to replace last week's "test" or not (perhaps the user had them in different directories)
give each user their own directory, this prevents performance problems and makes it easy to migrate, archive, or delete a single user
put metadata in the database and files in the file system
look out for code injection via file name
This is an interesting question. Depending on the level of security you want to apply I would recommend the following:
Choose a folder that is only accessible by your app server (if you chose to store in the FS)
I would always recommend to rename the files to a random generated hash (or incremntally generated name like used in URL shorteners, see the open source implementation of rubyurl). However, I wouldn't store them in a database because filesystems are built for handling files, so let it do the job. You should store the meta data in the database to be able to set the right file name when the user downloads the file.
You should partition the files among multiple folders. This gives you multiple advantages. First, filesystems are not built to handle millions of files in a single folder. If you have operations that try to get all files from a folder this takes significantly more time. If you obfuscate the original file name you could create one directory for each letter in the filename and would get a fairly good distributed number of files per directory.
One last thing to consider is the possible collision of file names. A user should not be able to guess a filename from another user. So you might need some additional checks here.
Depending on the level of security you want to achieve you can apply more and more patterns.
Just don't save the files in the public folder and create a controller that will send the files.
How you want to organise from that point on is your choice. You could make a sub folder per user. There is no need to rename from a security point of view, but do try to cleanup the filename, spaces and non ascii characters make things harder.
For simple cases (where you don't want to distribute the file store):
Store the files in the tmp directory. DON'T store them in public. Then only expose these files via a route and controller where you do the authentication/authorisation checks.
I don't see any reason to rename the files; you can separate them out into sub directories based on the user ID. But if you want to allow the uploading of files with the same name then you may need to generate a unique hash or something for each file's name.
See above. You can partition them any way you see fit. But I would definitely recommend partitioning them and not lumping them in one directory.

where is the best place to save images from users upload

I have a website that shows galleries. Users can upload their own content from the web (by entering a URL) or by uploading a picture from their computer.
I am storing the URL in the database which works fine for the first use case but I need to figure out where to store the actual images if a user does a upload from their computer.
Is there any recommendation here or best practice on where I should store these?
Should I save them in the appdata or content folders? Should they not be stored with the website at all because it's user content?
You should NOT store the user uploads anywhere they can be directly accessed by a known URL within your site structure. This is a security risk as users could upload .htm file and .js files. Even a file with the correct extension can contain malicious code that can be executed in the context of your site by an authenticated user allowing server-side or client-side attacks.
See for example http://www.acunetix.com/websitesecurity/upload-forms-threat.htm and What security issues appear when users can upload their own files? which mention some of the issues you need to be aware of before you allow users to upload files and then present them for download within your site.
Don't put the files within your normal web site directory structure
Don't use the original file name the user gave you. You can add a content disposition header with the original file name so they can download it again as the same file name but the path and file name on the server shouldn't be something the user can influence.
Don't trust image files - resize them and offer only the resized version for subsequent download
Don't trust mime types or file extensions, open the file and manipulate it to make sure it's what it claims to be.
Limit the upload size and time.
Depending on the resources you have to implement something like this, it is extremely beneficial to store all this stuff in Amazon S3.
Once you get the upload you simply push it over to Amazon and pop the URL in your database as you're doing with the other images. As mentioned above it would probably be wise to open up the image and resize it before sending it over. This both checks it is actually an image and makes sure you don't accidentally present a full camera resolution image to an end user.
Doing this now will make it much, much easier if you ever have to migrate/failover your site and don't want to sync gigabytes of image assets.
One way is to store the image in a database table with a varbinary field.
Another way would be to store the image in the App_Data folder, and create a subfolder for each user (~/App_Data/[userid]/myImage.png).
For both approaches you'd need to create a separate action method that makes it possible to access the images.
While uploading images you need to verify the content of the file before uploading it. The file extension method is not trustable.
Use magic number method to verify the file content which will be an easy way.
See the stackoverflow post and see the list of magic numbers
One way of saving the file is converting it to binary format and save in our database and next method is using App_Data folder.
The storage option is based on your requirement. See this post also
Set upload limit by setting maxRequestLength property to Web.Config like this, where the size of file is specified in KB
<httpRuntime maxRequestLength="51200" executionTimeout="3600" />
You can save your trusted data just in parallel of htdocs/www folder so that any user can not access that folder. Also you can add .htaccess authentication on your trusted data (for .htaccess you should kept your .htpasswd file in parallel of htdocs/www folder) if you are using apache.

Where in the filesystem do I store app's data files?

I need to store some data files for my blackberry app. These are usually small png files that I download and store locally for performance reasons. Also I need to store an xml file locally.
My question is where are these files supposed to be saved on a blackberry? Is there such a thing as an application's home folder or settings folder in the blackberry filesystem?
What would be the path to such a folder?
This is for blackberry os 4.7 or later.
Thanks!
If it's not a huge amount of data (and by the sounds of it, it's not), take a look at the PersistentStore mechanism. You can store many types of data including native types (String, Integer, etc.) and even byte[] data (for images) using PersistentContent. The nice thing about PersistentStore is that it doesn't require any sort of filesystem access -- it doesn't leave files hanging around -- and if you include a custom class in the persistent store for your app (even a simple subclass of an existing persistible class such as Hashtable), it will automatically delete your persisted data if the app is deleted.
There's no official home folder for your application. In blackberry you can basically read/write just about anything/anywhere (well, you might get a SecurityException/IOException if you'll try do change some files).
You can write to the SDCard/Internal memory using the paths described here.
If you're worried about someone seeing and altering your data there's not much you can do except setting your files and directories as hidden using FileConnection.setHidden(true) but this is very lame since they can still be seen even from the native BlackBerry file browser if the user chooses to show hidden files from the menu.
Edit: You could of course encrypt/decrypt your data but this won't prevent someone from deleting it.

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