YouTube API key gives 500 error when restricted to Android

Question

I am having a very difficult time querying the YouTube search API using a key that is secured for use on Android exclusively. It seems when I remove restrictions from this key,

Answer 1

After some trial and error, this appears to be caused by the format of the fingerprint sent in the x-android-cert header. Instead of accepting the same format required by the dev console (AB:CD:EF:01:23:...), it needs to be sent as a lowercased hex string (abcdef0123...). Hopefully this helps out the next soul unfortunate enough to run into this.