Story: Modify connection protocol to use DID Resolver component

[dbluhm]

As an ACA-Py user, I want to receive connection invitations with public DIDs from multiple ledgers, so that I can connect with agents rooted in multiple ledgers.

Replace current Indy ledger resolution of public DIDs with usage of new DID Resolver component.

Acceptance Criteria

• [x] Tests
• [x] No regression in functionality of Connections protocol
• [x] Dependence on BaseLedger in connections protocol invitation acceptance removed
• [x] Receive connection invitation with public DID from multiple ledgers
  • i.e. Indicio, Sovrin, etc.. Each are Indy so no dependencies introduced between this and the next phase.

[Luis-GA]

I have been a while trying to figurate out what I have to do. After a global view and a specific view, I guess that I have to do some changes in the files “manager.py” and “base_manager.py”.

I have some questions:

• “BaseLedger” should be replaced by the resolver/base “BaseDIDResolver”?

• I am totally lost with the “Receive connection invitation with public DID from multiple ledgers” This is something to be approached editing the “conn_record.py”? From my understanding this function is agnostic, isn’t it?

[dbluhm]

If you haven't already, read the following Aries RFCS, paying particular attention to anywhere the phrase "public DID" is used:

• https://github.com/hyperledger/aries-rfcs/blob/master/features/0160-connection-protocol/README.md
• https://github.com/hyperledger/aries-rfcs/blob/master/features/0023-did-exchange/README.md

ACA-Py uses a "Ledger" (really an Indy ledger) to resolve a info that it subsequently uses to send a connection request. In the connection/DID exchange managers, you'll find instances of the calls ledger.get_key_for_did and ledger.get_endpoint_for_did. These should be replaced with something that looks like:

resolver = session.inject(DIDResolver)
doc = await resolver.resolve(did)
didcomm_service = doc.dereference(...)
# ... use service to form connection target

It may be useful for us to implement a ConnectionTarget.from_service or similar to make using the service more straightforward. Looking through usages of ConnectionTarget may be informative.

[dbluhm]

A DIDDoc.get_service_by_type may also be useful in retrieving the registered didcomm services from the doc in priority order.