I was wondering why the base64 string is 43 characters long for a 32byte Ed25519 key. 32*8/6=42
That is because tor drops trailing '=' from base64 encoded values within descriptors. Some fields indicate this within the spec, others don't.
https://gitweb.torproject.org/stem.git/tree/stem/util/str_tools.py#n98
I'd like to use "ed25519 identity" or even just "identity" here going forward.
Gotcha. The name of 'identity' makes me wonder how this relates to relay fingerprints, which are the canonical identifier we use.
Regardless, the more we can standardize the terminology we use the less confusing these fields will be.
Cheers! -Damian