Support address allow/deny lists on source subnet

[cam-schultz]

Context and scope
Relayers are configurable to relay Warp messages created via different messaging protocols, e.g. Teleporter. However, relayer operators may wish to only relay messages sent by a specific set of addresses, for instance if they want to tie relayer gas expenditure due to message delivery to transactions initiated by known addresses. Relayers may also be liable for compliance violations if they deliver messages sent by a sanctioned address.

We should add configuration options on the sending subnet to allow relayers to apply filters at the address level.

Open Questions

• The contract that calls the warp precompile to send the message is the address listed in the Warp AddressedCall payload type. For example, this is the TeleporterMessenger contract address for Teleporter messages. How would we get the original transaction sender in the relayer? Is that included in the message logs/receipt?
• There are two addresses to consider: the EOA that initiates the transaction on the source blockchain, and the address that calls Teleporter (or another messaging protocol). It makes sense to filter on both, but they may need to be treated differently.

[Nuttymoon]

Hi, is there a timeline for this issue? This is a hard requirement to go to mainnet IMO.

[cam-schultz]

Added to the current milestone. Agreed this is a feature we should implement soon.

[cam-schultz]

It will most likely make the most sense to implement #80 alongside this, as the source and destination addresses take on a different role with #240