I have built a vb.net web application. I have tried to make it secure, with all users requiring a password to get in.
The only problem is that if anyone can guess (or detect using some kind of hacking tools) the url of the javascript file, they can download it and read it, without even having to log in first.
Is there any way that this can be prevented?
If the javascript file is not required as part of the logon process, then you can secure the file on the server so your users need to be authenticated and authorized in order to access it. This will prevent unauthorized access. Approaches to securing this file include using file system Access Control Lists (ACLs - 'Windows file permissions'), or using the "authorization" element in the ASP.NET web.config.
If the javascript file is required as part of the logon process, then you've got to give anonymous (unauthenticated) accees to the file, in which case you cannot prevent people being able to download it.
Don't serve the JS file up to people who haven't authenticated.
I don't known ASP.NET well enough to say what the best approach would be, but worst case is you stick it in a .aspx file, do the auth/authz stuff at the top, then set the right content type and serve it.
