Multiuse invitations: Agent unable to respond to messages

[antoncuranz]

Hello, I recently encountered a bug concerning the use of multiuse invitations:

Let's consider the following scenario involving two Agents, Alice and Bob:

Alice creates a multi-use invitation and sends it to Bob.

After the connection was established, Alice has two connection entries:
1: An active one representing the just established connection to Bob
2: A second one in state „invitation“ for the multi-use invitation

Bob only has one active connection to Alice.

If Bob now sends a message (e.g. a discover-features v2.0 query) to Alice, Alice’s agent complains that the connection is not active and does not reply.

I only used public DIDs for the connections (did:sov:xyz).

As far as I understand, this is due to the connection caching in connections/base_manager.py:

aries-cloudagent-python/aries_cloudagent/connections/base_manager.py

Lines 969 to 990 in 2d2106e

	cache = self._profile.inject_or(BaseCache)
	if cache:
	async with cache.acquire(cache_key) as entry:
	if entry.result:
	cached = entry.result
	receipt.sender_did = cached["sender_did"]
	receipt.recipient_did_public = cached["recipient_did_public"]
	receipt.recipient_did = cached["recipient_did"]
	async with self._profile.session() as session:
	connection = await ConnRecord.retrieve_by_id(
	session, cached["id"]
	)
	else:
	connection = await self.resolve_inbound_connection(receipt)
	if connection:
	cache_val = {
	"id": connection.connection_id,
	"sender_did": receipt.sender_did,
	"recipient_did": receipt.recipient_did,
	"recipient_did_public": receipt.recipient_did_public,
	}
	await entry.set_result(cache_val, 3600)

In find_inbound_connection, Alice caches the invitation connection while connecting to Bob.
Once the connection is established, the cache still returns the same result even though there is now an active connection.

I applied a quick fix by only caching the connection if it is not in state "invitation“, which solves this problem.

if connection.state != ConnRecord.State.INVITATION:
    await entry.set_result(cache_val, 3600)

But it would probably be better if the cache entry is updated as soon as the connection is established.