I'm creating an ASP.NET web application to schedule tasks on our server from a remote location using a .NET Wrapper for Scheduled Tasks. However, I'm stuck.
The user needs to be able to browse the file system on the server to retrieve a "file to run" for the new task that the user's creating in this application. I need to get the filepath/filename and pass it into the .NET wrapper.
I've tried using HTMLInputFile, but I haven't found a way to make that work for me.
Any help is appreciated.
Thanks
Update:
For this project, we've decided to simply list the executables in a dropdown box that would be available to users since they don't really need total access to the file system, just for security's sake.
HTMLInputFile is used to browse the client's file system and upload a file to the server. It isn't used to browse the server's file system.
You will need something quite different. You will need some server side code to display the server side folder structure to the user via the browser.
There is an example of a basic implementation of this here.
Update:
With that sample, the path that you replace "yourfolderHere" with needs to be a virtual path, rather than an absolute path. So for example "C:\Inetpub\wwwroot\uploads" won't work, but "uploads" will work.
I hope it goes without saying that there are serious security issues to think about when implementing something like this.
The HTMLInputFile will only work on the client-side machine.
You need to write a filesystem browser in ASPX/HTML that browses on the server-side.
Shouldn't be that hard to do.
You can't use the <input type="file" tag
This brings up a client-side dialog that browses the client machine.
As far as I am aware you need to create your own 'browser'.
eg You could use the My.Computer.Filesystem classes to retrieve a list of files in a folder and show those on the webpage. The user then selects the relevant file and posts a response back to the server.
You can use System.IO.Directory to get directories and files. These can be displayed in a number of ways. A simple browser / file selection should be possible in less than 50 lines of code.
Also be aware that you may need to grant extra permissions to the user that your web app runs as so the file system is accessible.
There are also various security implications around this, so don't grant access to everything unless you really need this.
Related
As the title says, how would I go about doing this? I want to check a value stored in a file.
This is impossible and has nothing to do with ASP .NET. The browser is responsible for rendering the page to the client, and browsers, for obvious reasons (security), don't have access to the user's file system. The only thing a browser can do, is read cookies (essentially text files) sent to the user from the same domain the website belongs to.
HTML5 has a new feature called local storage but you still won't be able to access ANY file on the user's computer.
Using Javascript with ASP.Net applications can work quite well, I've done it for a couple of sites I've done. If you just want to run some code on the client when a checkbox is ticked for instance, try this...
replace the myFunction() portion out with whatever client side code you want to write.
If you unfamiliar with Javascript as a language, check this out... http://www.w3schools.com/js/default.asp
You can do that using ActiveX control or SilverLight
Some are saying it's not possible, and that is true for the Internet. However, I have done this before on an Intranet system. The server knew the users computer name and could access a local configuration file, no ActiveX, no Silverlight.
I have a hyperlink to an executable like so: Run Now
I'm trying to make the download dialog box appear without the save function as it is to only run only on the user's computer.
Is there any way to manipulate the file download dialog box?
FYI: Running on Windows Server '03' - IIS.
Please no suggestions for a WCF program.
Okay I found it for anyone stumbling upon this conundrum in the future.
Add the following tag to your head section: <meta name="DownloadOptions" content="nosave" /> and the file download dialog box will not display the "save" option.
For the user to not open/run but save replace "nosave" with "noopen"
Not unless you have some control over a user's machine. If your application can run on limited resources, you might want to consider doing it in Silverlight.
IMO, having a website launching an executable is a pretty bad idea.... even worst if that website is open to the general public (not on intranet). I don't know what that app is doing but it sure is NOT, 1) cross browser, 2) cross platform, and 3) safe for your users.
If you are on intranet, you might get away with giving the full server path (on a shared drive) to the executable and change security settings on your in-house machines.
Other than that, you won't succeed in a open environment such as the Internet.
From your comments, if the user downloading the file is the issue, then there's no way to get around it, as they have to download the file in order to be able to run it.
There's any number of ways to get around whatever you could manage in browser, from proxies like Fiddler intercepting the data, or lower level things like packet sniffing. Or even simply going into the browser's temp/cache folder and copying the file out once it's running.
You could probably get around most laymen by having a program that they can download that registers a file extension with Windows. Then the file downloaded from this site would have the URL of the actual data obfuscated somehow (crypto/encoding/ROT-13/etc). The app would then go and grab the file. The initial program could even have whatever functionality provided by what you want to download, but it needs the downloaded key.
But this is moving into the area of DRM and security by obscurity. If an attacker wants your file, and it's on the Internet, they will get the file.
Is there a way to programmatically set the name of a file to be uploaded from a web page? I suspect that browser security restrictions make this impossible, but I'm hoping someone will prove me wrong.
I have a web application that needs to let the administrator upload HTML. The admin selects the HTML file, then the app uploads that file, plus figures out all the supporting files (images, stylesheet, etc) and uploads them too. There doesn't seem to be a way to programmatically upload the supporting files from a web page, since the user has to specify each file explicitly.
Currently I have a separate Windows app to do this, but it would be ideal to have this functionality integrated with the rest of the app. My back end is ASP.NET with C#.
There is no way to programatically grab files from a user's computer via the browser. This would be a security violation if a website could just grab things.
Yes you can (in modern browsers)...
You can get and set the value of HTMLInputElement.files.
See this answer.
No, you cannot do this without a client-side application or special plug-in.
Browser security doesn't allow the server to obtain information about the hard drive contents of the client.
You may be able to do this using some form of browser plug-in. This is more work for you (and there are potential security implications for this beyond those found when you just have users run your app). However, it may prevent a more integrated experience for your users. I'd hesitate to eliminate the application completely, though. Browser compatibility issues are common.
Let's say we have a web site with a CF app that was written in-house.
Assume that:
Server 2003 IIS6 or 2008 IIS7 will be used
ColdFusion 8 will be used
Directory browsing is denied
SSL is required to connect
The account login process is secure (yeah I know that is a whole other
ball of wax but that concept is discussed ad nauseum on the web).
Say I have a file at https://domain.com/folder1/folder2/ with a name like picture92352.ext imagine it as a jpg or pdf or whatever. The entire path between the domain name and the file varies widely in naming structure, depth, etc. Files are not all lumped together in one folder.
The app restricts links by user such that a user would have to have access to that file to find it in the first place but as it stands now if a person knew the full URL to that file they could retrieve it without logging in to the app. It's the classic security by obscurity situation. A random person isn't likely to find a file they shouldn't get to but once someone is given access they know how to access it from another PC where their actions might not be traced back to them.
How do I restrict access to these files before someone logs in and still make them accessible to outside users after they log in? Is there a way to do it with permissions only or is the only answer to have code dynamically moving files around at the time of the request or is there some obvious step I'm not even thinking of?
Let me clarify this slightly. No matter how the file is presented on a page a user can use the browser IE, Firefox, etc to examine the URL the file comes from. If the image is a link there is always copy shortcut in the right click menu for IE and the same functionality in FF is called copy link location. If the image is displayed inline as part of the page an IE user can right click and choose properties to see the URL, in FF the same functionality is present to see properties but there is an even quicker more convenient option labeled copy image location. Once a user knows the URL to a file if the location or file name doesn't change they can use that URL without authenticating in the CF app.
If I change the NTFS/share permissions so that IUSR can't see the content then my CF app and IIS can't push it. What strategy do I use to provide the file in the CF app that doesn't leave this hole open?
You could write a CFM page that serves up the images. Then you just make sure they are authenticated inside the CFM.
<!-- something like this -->
http://localhost/GetFile.cfm?file=foobar.jpg
In GetFile.cfm, you would do something like:
<!-- the filename part is what the browser will pre-popualate the file name in the download dialog as -->
<CFHEADER name="Content-disposition" value="attachment;filename=picture92352.ext">
<CFCONTENT type="text/plain" file="\\fileserver\folder1\folder2\picture92352.ext">
Take a look at the various MIME types.
If you wanted to do something similar but keep a more natural URL, I think you would need to leverage the Java servlet underpinnings of ColdFusion to create a handler for any URL matching a certain pattern.
I am trying to find out how to upload a file from a web user to a server using an ASP page. The displayed page has an Input tag of type "File" like this:
<input type="file" name="uploadfile">
And a submit button that passes the Form info to another .ASP page. This page must take the path it gets from the Input control and use it to somehow save the file to the server.
I keep thinking there must be a common way to do this, since I see this kind of thing on a number of websites, but how is it done? Is there some sort of server object that can be called for it?
This script will help you.
Also, you may google for "asp upload file" - there are tons of results.
If you are doing any serious uploading or have a commercial product you really need to use a COM component in classic asp. Check out SA-FileUp. It has been the defacto standard for this since like forever.
If your hosting service doesn't allow you to install components, you may also want to look at this script:
http://chris.brimson-read.com.au/index.php?option=com_content&view=article&id=6&Itemid=7
I've seen a wide variety of upload scripts floating around, and they ... vary ... in quality. I've not used the script in the selected answer, but its worth trying a few different options.
I can recommend SA-FileUp and Dundas Upload. They both are easy to install and have good tutorials on how to implement.