Use of companion devices with HAIP #248
Description
As posted by Martijn we may need to be clearer on how companion devices work in HAIP, e.g. the requirement to support haip:// for credential offers might not work well.
My interpretation of the mdoc issuance profile as proposed in this PR is that it mandates support for supporting the same-device and cross-device flow for credential offers. However it's not well-defined what that means. VCI says the following for same-device and cross-device:
"The End-User may receive the Credential Offer from the Credential Issuer either on the same device as the device the Wallet resides on, or through any other means, such as another device or postal mail, so that the Credential Offer can be communicated to the Wallet."
So this would mean that as long as the credential offer can be received "through any other means" there is compliance to the cross-device flow requirement. I don't think that in itself provides any interoperability benefits.
For the same-device scenario, how does the same-device requirement apply to companion devices. Does this means that in order to be HAIP-compliant, the companion device must be able to handle all requirements in HAIP on its own, i.e. to effectively act as a stand-alone device.
One option would be to recommend support for the different flows, but if we mandate them it should be clear what it means to be compliant to these requirements and how that works for companion devices.
Originally posted by @martijnharing in #228 (comment)