joe petrowski
c79b234b3b
The goal of this PR is to migrate Identity deposits from the Relay Chain to a system parachain. The problem I want to solve is that `IdentityOf` and `SubsOf` both store an amount that's held in reserve as a storage deposit. When migrating to a parachain, we can take a snapshot of the actual `IdentityInfo` and sub-account mappings, but should migrate (off chain) the `deposit`s to zero, since the chain (and by extension, accounts) won't have any funds at genesis. The good news is that we expect parachain deposits to be significantly lower (possibly 100x) on the parachain. That is, a deposit of 21 DOT on the Relay Chain would need 0.21 DOT on a parachain. This PR proposes to migrate the deposits in the following way: 1. Introduces a new pallet with two extrinsics: - `reap_identity`: Has a configurable `ReapOrigin`, which would be set to `EnsureSigned` on the Relay Chain (i.e. callable by anyone) and `EnsureRoot` on the parachain (we don't want identities reaped from there). - `poke_deposit`: Checks what deposit the pallet holds (at genesis, zero) and attempts to update the amount based on the calculated deposit for storage data. 2. `reap_identity` clears all storage data for a `target` account and unreserves their deposit. 3. A `ReapIdentityHandler` teleports the necessary DOT to the parachain and calls `poke_deposit`. Since the parachain deposit is much lower, and was just unreserved, we know we have enough. One awkwardness I ran into was that the XCMv3 instruction set does not provide a way for the system to teleport assets without a fee being deducted on reception. Users shouldn't have to pay a fee for the system to migrate their info to a more efficient location. So I wrote my own program and did the `InitiateTeleport` accounting on my own to send a program with `UnpaidExecution`. Have discussed an `InitiateUnpaidTeleport` instruction with @franciscoaguirre . Obviously any chain executing this would have to pass a `Barrier` for free execution. TODO: - [x] Confirm People Chain ParaId - [x] Confirm People Chain deposit rates (determined in https://github.com/paritytech/polkadot-sdk/pull/2281) - [x] Add pallet to Westend --------- Co-authored-by: Bastian Köcher <git@kchr.de>
Identity Module
Overview
A federated naming system, allowing for multiple registrars to be added from a specified origin.
Registrars can set a fee to provide identity-verification service. Anyone can put forth a
proposed identity for a fixed deposit and ask for review by any number of registrars (paying
each of their fees). Registrar judgements are given as an enum, allowing for sophisticated,
multi-tier opinions.
Some judgements are identified as sticky, which means they cannot be removed except by complete removal of the identity, or by the registrar. Judgements are allowed to represent a portion of funds that have been reserved for the registrar.
A super-user can remove accounts and in doing so, slash the deposit.
All accounts may also have a limited number of sub-accounts which may be specified by the owner; by definition, these have equivalent ownership and each has an individual name.
The number of registrars should be limited, and the deposit made sufficiently large, to ensure no state-bloat attack is viable.
Interface
Dispatchable Functions
For general users
set_identity- Set the associated identity of an account; a small deposit is reserved if not already taken.clear_identity- Remove an account's associated identity; the deposit is returned.request_judgement- Request a judgement from a registrar, paying a fee.cancel_request- Cancel the previous request for a judgement.
For general users with sub-identities
set_subs- Set the sub-accounts of an identity.add_sub- Add a sub-identity to an identity.remove_sub- Remove a sub-identity of an identity.rename_sub- Rename a sub-identity of an identity.quit_sub- Remove a sub-identity of an identity (called by the sub-identity).
For registrars
set_fee- Set the fee required to be paid for a judgement to be given by the registrar.set_fields- Set the fields that a registrar cares about in their judgements.provide_judgement- Provide a judgement to an identity.
For super-users
add_registrar- Add a new registrar to the system.kill_identity- Forcibly remove the associated identity; the deposit is lost.
License: Apache-2.0