Bluesky users occasionally get created without AP keys

[snarfed]

Not common, only seeing one of these every couple weeks or so, but still weird. What's happening here?

https://console.cloud.google.com/errors/detail/CKXLrIb56cr0zQE;locations=global;time=P30D?project=bridgy-federated&invt=AbuwZw

GET https://bsky.brid.gy/ap/did:plc:65isvpdvlh7ttv5tyk5jir4t 

ValueError: Invalid RSA public exponent 
at .construct ( /layers/google.python.pip/pip/lib/python3.12/site-packages/Crypto/PublicKey/RSA.py:647 )
at .public_pem ( /workspace/models.py:708 )
at .postprocess_as2_actor ( /workspace/activitypub.py:1014 )
at ._convert ( /workspace/activitypub.py:447 )
at .convert ( /workspace/protocol.py:603 )
at .actor ( /workspace/activitypub.py:1083 )
at .decorated ( /layers/google.python.pip/pip/lib/python3.12/site-packages/oauth_dropins/webutil/flask_util.py:366 )
at .dispatch_request ( /layers/google.python.pip/pip/lib/python3.12/site-packages/flask/app.py:902 )
at .full_dispatch_request ( /layers/google.python.pip/pip/lib/python3.12/site-packages/flask/app.py:917 )
at .handle_exception ( /layers/google.python.pip/pip/lib/python3.12/site-packages/oauth_dropins/webutil/flask_util.py:252 )
at .handle_user_exception ( /layers/google.python.pip/pip/lib/python3.12/site-packages/flask/app.py:809 )
at .full_dispatch_request ( /layers/google.python.pip/pip/lib/python3.12/site-packages/flask/app.py:919 )
at .wsgi_app ( /layers/google.python.pip/pip/lib/python3.12/site-packages/flask/app.py:1511 )

We generate AP keys in get_or_create:

bridgy-fed/models.py

Lines 390 to 402 in fe51b1f

	# generate keys for all protocols _except_ our own
	#
	# these can use urandom() and do nontrivial math, so they can take time
	# depending on the amount of randomness available and compute needed.
	if cls.LABEL != 'activitypub':
	if (not user.public_exponent or not user.private_exponent or not user.mod):
	assert (not user.public_exponent and not user.private_exponent
	and not user.mod), id
	key = RSA.generate(KEY_BITS,
	randfunc=random.randbytes if DEBUG else None)
	user.mod = long_to_base64(key.n)
	user.public_exponent = long_to_base64(key.e)
	user.private_exponent = long_to_base64(key.d)

[snarfed]

Aha, this happens when we've already created a user before they enable the bridge. In User.get_or_create, we return the existing user and never create AP keys or do other network-specific setup.

Should be a straightforward fix.

[snarfed]

Had to revert 9f9ecce since it may have caused #1929. 😕