Photo gallery plug-in with password and favorites list

I am developing the site of a photographer, who would like his clients (weddings) to be able to see the photographs of his event, and be able to select his favorite photographs.

And that list of favorites, he can see it.

Even if it could be protected by password, and it is free it would be great.

There is a site called Pixieset that does this, but he would like something like that to be implemented on his site.