Comment 18 for bug 206129

I have thoroughly read this thread in an effort to find a solution to this issue for my machine as well. I have discovered something that it probably obvious to most but clearly wasn't to me. If you are intent on aliasing sha265 to something like sha256_generic, but sure you do not blacklist both sha256 and sha256_generic! This is a sure way to lock you our of your encrypted partitions.

Fortunately I did not encrypt my root partition (something I highly recommend you don't do!) and was able to de-blacklist sha256. This seemed to fix my issue with not being able to decrypt the partition.