Flow•6mo ago

Bohao | Flow (2024-05-02)

I also have a question about Account Linking. For a Public Account (accout reference by getAccount) in a contract (that means unable to use specialized methods like getAuthAccount in script), is it possible to determine whether it has an existing linked Account Capability? (The OwnedAccountPublic Capability can indeed be queried using forEachPublic, but using the link Account Capability does not mean using HybridCustody.) Purpose: Determine if this address is under third-party control.

30 Replies

Needle•6mo ago

I've created a thread for your message. Please continue any relevant discussion in this thread. You can rename this thread using /title <new title> If this is a technical question that others may benefit from, considering also asking it on Stackoverflow: https://stackoverflow.com/questions/ask?tags=onflow-cadence

Bohao•6mo ago

cc @Austin | flowty.io @Bastian | Cadence @Giovanni S | Flow

Unknown User•6mo ago

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Bohao•6mo ago

No, my goal is just the last sentence. As long as this goal is achieved, it's fine. But this must be in the contract, it is a utility method in the contract. This is a judgment of security requirements, Sometimes you may want to know if the address is fully controlled by oneself.

Unknown User•6mo ago

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Bohao•6mo ago

It's exactly what I'm worried about... I can only determine whether it holds OwnedAccountPublic at most.

Unknown User•6mo ago

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Bohao•6mo ago

Because it is a utility method in a contract...

Unknown User•6mo ago

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Bohao•6mo ago

Yeah, making branch decisions based on the result of this judgment. This is obviously a view fun.

Unknown User•6mo ago

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Bohao•6mo ago

Yeah... The current limit is knowing whether HC is being used. It is not possible to determine from the perspective of the Contract method whether the address is being used by a third party. (That means whether some account capabilities exist)

turbolent•6mo ago

Do you want to be able to check this for any account, without it needing to be prepared for that check? Or is it sufficient that the owner of the account deployed a contract to their account that you can then use to check that account?

Unknown User•6mo ago

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Bohao•6mo ago

Obviously we need to consider C1.0...

Unknown User•6mo ago

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Bohao•6mo ago

I think it should be any account... This is obviously a view fun type of query... and it is mainly used to determine the security status of the account... Some DeFi-like business behaviors may require judging whether self.owner has been controlled by a third party in resources to ensure security. My use case here is that I hope this address is complete without keys and uncontrollable (in a completely uncontrollable state).

Unknown User•6mo ago

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Bohao•6mo ago

Yeah This judgment needs to be completed in the contract. It must be uncontrollable.

Unknown User•6mo ago

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Bohao•6mo ago

This is a very common declaration of no control in other public chains. You can understand it this way, this resource is safe at this address because the address cannot be controllable, so you can play freely.

turbolent•6mo ago

For now you need to deploy a contract to the account, but we could also consider exposing this as a built-in, it seems valuable

Unknown User•6mo ago

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turbolent•6mo ago

Sorry, what do you mean? It could be part of the larger discussion around the functionality for locking down accounts more. For example, currently you can make contracts only immutable if you remove all keys. But with account capability controllers, there’s still a way to add back keys or change contracts

Bohao•6mo ago

I'll put it in a different way. This is more common in scenarios similar to memecoin on some other public chains. For example, I issued an asset and then moved all ownership or something like that. Here corresponds to an address in Cadence where this resource is in a completely uncontrollable state. In fact, it is only judged in the Resource contract whether the address (self.owner) is uncontrollable. This address also can be just a user address, but yeah, it is more about determining the service account and there may not be a contract deployed in it (Just need to have resources in the address). This is where it differs from other public chains. As long as there are resources in the address, any address can become a service address. I found that this is also an advantage of Cadence compared to other public chains 😆 Other public chains require the address with deployed contracts to become a service address, but we can easily create a three-party service model. Platform -> Building Contract -> Service Platform Creator / Devs -> Use platform -> Setup Service Resource in an Account -> Act a Service provider User -> use Service

Giovanni S•6mo ago

Good callout, anyone should be able to identify if an account can be controlled whether by key or account capability

Unknown User•6mo ago

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Giovanni S•6mo ago

True. Still the pattern that currently exists for checking if an account cap exists has no analogue in 1.0. Might be worth adding a method on Capabilities like

access(all) struct Capabilities {
  // Strawman syntax
  access(all) view fun hasActiveAccount(): Bool {
    return self.account.controllers.length > 0
  }
}

access(all) struct Capabilities {
  // Strawman syntax
  access(all) view fun hasActiveAccount(): Bool {
    return self.account.controllers.length > 0
  }
}

which should be possible to call on an unentitled account

turbolent•6mo ago

@Bohao | Flow could you please open a feature request issue for this in the Cadence GitHub repo? I think it’s difficult to implement a truly complete solution for this, because even when knowing that there are no controllers, there still might be a contract in the account that provides equivalent functions

Bohao•6mo ago

https://github.com/onflow/cadence/issues/3312 Created

GitHub

Add an unentitled way to identify if an account be controlled by ac...

Issue to be solved The current exposed interface of the account cannot allow anyone to know whether the address has an Account Capability. This will make it impossible to implement some logic that ...

Gaming

Programming

Bohao | Flow (2024-05-02)