Authentication is hard. And that's exactly why you should never have to be writing your own auth code, but rather, use existing frameworks.
There's so many tiny details and edge cases that can have such catastrophic results, it's too much of a risk to do it yourself. Unless writing auth frameworks is your job, for course.
There's so many tiny details and edge cases that can have such catastrophic results, it's too much of a risk to do it yourself. Unless writing auth frameworks is your job, for course.