KeePass is an open source password manager. The passwords are stored in a database with the .kdbx extension. The database can be on your local file system or on a web server. If you put the database on an IIS webserver, you can access it from KeePass, but if you try to save, you get a 404 error.This is because the StaticFile HTTP handler in IIS only supports the GET method and KeePass requires PUT, MOVE and DELETE, in addition to GET.

To add support for this, a custom HTTP handler has to be added to the webserver. The HTTP handler is a C# library project with a class that implements IHttpHandler. A reference to System.Web needs to be added.

To add the handler, put the following in web.config:

Put the library DLL in a folder named "bin" on the web site.

Now, you should be able to save your KeePass database!