Update: spelling
Greetings
First if you need directions you are going to have to give us more informations:
When you say log in, what kind of login do you mean,

• Login with ssh?
• Login on a web service?

Those are the two kinds I can think of in your case, the approach will vary wildly depending on the kind of login.
In the ssh case it could be as simple as displaying in the terminal a list of files and one time download links or just copy the selected files in the user's home folder...
If you want a web service then you are going to need to set up a server that will give content to users, a database for the login to take place.
If the files in question should not be modified by the users , catalyst as a plugin, Static::Simple iirc that can be used just for that. Type the url, the file name and voila it will start downloading
A precise answer to a vague question requires mind reading, I have not upgraded my brain to that stage yet ;)