[🚀 | Feature request]: Port: Shamir-based shared recovery device

[mmmarcos]

Shamir-based shared recovery device is described in RFC 1000.

It was implemented for the V2 branch in the following PRs:

• Implementation of shamir-based shared recovery device  #4504
• Decouple get_shamir_recovery_share_data from ShamirRecoveryGreetInitialCtx #4929
• Add missing serde tests for shamir recovery certificates #5946

It must be ported to the V3 branch (master).

NOTE: V2 implementation was CLI-based, so the GUI part (#8671) is out of scope for the moment.

Task List

• [Shamir port] server side shared_recovery_device_info #7362
• [Shamir port] server side list_shared_recovery_devices #7360 (edit: it's already in get_certificates)
• Shamir port: server side route create_shared_recovery_device #7357
• Infinite loop when using Client::shamir_setup_create #8206
• [Shamir port] server side: invite_new_shamir_recovery #7359
• [Shamir port] implement client side  #7363
• [Shamir port] Implement greeting procedure #8841
• [Shamir port] implement postgresql version #7358
• [Shamir port] CLI commands #8672
• [Shamir port] Certificate deletion  #7364
• [Shamir port] server side remove_shared_recovery_device #7361
• [CLI] Implement shared recovery invitation process  #9180
• Should we replace sharks with blahaj ? #8990

The GUI would not be implemented right now, so we can leave the following issue for later:

• [Shamir port] add GUI bindings #8998

Test protocol

Setup

TODO: Describe how to local setup for testing this feature (testbed ? local server ? ...)

Tests

TODO: List some test cases to be performed when reviewing the feature.

[AureliaDolo]

With @vxgmichel we discussed the possibility of adding a few checks that are technically valid but make the shamir questionable:

• if a recipient has strictly more than threshold (exactly threshold will have the same behavior)
• if a recipient can use the setup on their own (ex: only one recipient, one recipient has threshold shares)

[mmmarcos]

@vxgmichel I've added a Test protocol section to the issue description. Please complete so we can use it to test the feature when its finished.

[AureliaDolo]

Before closing, we should add the corresponding newsfragment (see #9232 (comment))