Somehow I managed to really mess up my debian installation and I will have to reinstall it. However I have some data on the partition that I really want to save. Is there any way to access the data on the linux partition through OSX? The linux partition is encrypted...
If it's encrypted, and I assume that you know your own password, you can try something like
rescatux or more simply
gparted which will allow you to manually mount your disk. Chances are high that they share the same encryption libraries since they are all Debian-based distros. So they may offer to decrypt on mount.
More distros that offer full suites of rescue tools may be found here.
For example, Kali Linux is more robust and feature-rich. Also Debian-based to help with your scenario.
OSX will not play well.
Your best bet is to hook up an external drive and use dd to clone the drive - make sure your external drive is formatted. dd will take a long time so you will need to be patient. After the disk is copied you can mount the drive and use encryptfs commands (along with your password) to access the contents. If it is critical data then you will also need nerves of steel :).