Multer: Stop/Prevent file upload if user not authorized

[lorenzotsi]

I'm looking for a way to prevent upload in case of not authenticated user

I'm using Express which is configured to use passport as auth middelware.

I thought to use onFileUploadStart to reject the file, but I cannot find a link with "request" object, with which it would be possible to match the user.

Thanks
Lorenzo

[hacksparrow]

Load the auth middleware before multer.

[lorenzotsi]

...
// Multipart file upload
app.use(multer(
{
  dest: wwwroot + path.sep + 'uploaded' + path.sep, 
  onFileUploadStart: function (file) {
    //TODO : apply security check : user auth, file size, number...
    console.log(file.fieldname + ' is starting ...')
},
onFileUploadComplete: function (file) {
    console.log(file.fieldname + ' uploaded to  ' + file.path)
}
}));
...
app.use(passport.auth.initialize());
app.use(passport.auth.session());

I've tried to put the last 2 lines before multer init, but no way. Is it some other middleware for security you're referring to? Or Is there a way to access request object inside onFileUploadStart()? In that case I would be able to check the user.

Thanks

[lorenzotsi]

@hacksparrow Could you give me advice, please? I can't catch if it is a limit of express, of multer , both, a versions uncompliancy or myself in making mistake with the config, Thanks

[sigurdga]

@lorenzotsi You can do the auth check on the route that receives the files. I use passportjs and get a req.user I can do checks on.

[lorenzotsi]

@sigurdga Thanks for your support, but that can be applied after. I mean, first the file is uploaded (that is what I'm trying to prevent), in the route I could then cancel the just uploaded file in case user not logged in. I hoped in a better solution.

[jpidelatorre]

@lorenzotsi You need to use multer per route instead of globally. (https://github.com/jpfluger/multer/blob/examples/multer-upload-files-to-different-directories.md)

Then you can add an auth middleware before multer like this:

router.post('/uploads', function (req, res, next) {
    if (!authorized) {
        res.send(403);
    } else {
        next();
    }
},
multer({ dest: '/uploads/' }),
function (req, res, next) {
   // whatever you were planning to do.
});

I know it's late, but I hope it ends up helping someone.

[hailq]

But what happen if i need to parser the form data to get the authentication value? What should i do in this case?