Not just a mp3 file. any media you have purchased can be format shifted by you for archive/personal purposes. regardless of DRM/copy protections. What is illegal is redistribution (thus the copyright).

Again: ianal. But this is kind of a fundamental right. If you own something, it's yours to do with privately as you wish. If you don't own the copyright, then you can't redistribute.

The DMCA makes breaking DRM illegal, even when done for fair use purposes, if it doesn't fall into a small number of tightly-defined exceptions. And they can go after tools that enable people to do this, as well (think of DeCSS for example).