Ability to specify which addresses to request messages on behalf of

[martinhpedersen]

Initial discussion: https://groups.google.com/g/pat-users/c/5G1JIEyFXe4 (ping @bseidenberg).

The B2F protocol allows for specifying which addresses to request messages on behalf of through the ;FW command. This is not limited to tactical addresses, and there is nothing in the protocol specifying that the local station's primary address must be included. As a result, the protocol and Winlink CMS allows to request messages on behalf of arbitrary addresses as long as the user can provide the correct credentials ("secure login" password).

It's not yet clear to me how to wrap this up as an intuitive feature, but if done properly I think this might be very powerful in some scenarios.

Some use cases that comes to mind:

• Request messages for tactical address(es) only. (ref initial discussion)
• Request messages on behalf of a third party's account, while using the operator's callsign to identify the station "on air".
• P2P relaying. Being able to receive someone else's traffic with the intent to forward it to the final recipient. E.g. "man in the middle" relays.

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To get started with some experimentation, I'm going to add an environment variable (FW_AUX_ONLY_EXPERIMENT=1) limiting message reception to the auxiliary addresses defined in the config. This will hopefully give us some insights as to how it behaves in the real world.

[martinhpedersen]

@bseidenberg - I've pushed this to the develop branch now, and it will also be included in the next release (v0.15.1) 🙂 I don't think we need to rush this, so take your time testing with the experimental env variable. Please share your experience along the way 😄

[bseidenberg]

@martinhpedersen Will do, and thank you! I plan on picking this up soon-ish.