How to get user's public key by address account?

[biryusal]

Hi guys!
I've already searched all the APIs, but I still couldn't find — how do I get a user's public key, having only his address?

I want to do this in order to be able to verify a message signed by a user — without referring to his smart contract.

Because, as I understand it, when creating a wallet, the creation of a smart contract occurs only after you have an "enabled account" - and for this you need to make a transaction yourself or receive it (at least, my experiments have shown exactly this)

I have found only those APIs that allow you to get a public key over a private one — but this does not suit me, because I cannot take the user's private key in any way

[ivpavici]

Afaik it is not possible without referring to his smart contract! Addresses are hashes of the public key + some more params like account class hash, deployer address and callData:

const OZcontractAddress = hash.calculateContractAddressFromHash( starkKeyPub, OZaccountClassHash, OZaccountConstructorCallData, 0 );

cc @PhilippeR26 correct me if I'm wrong please!

[PhilippeR26]

You have to query Starknet.

const publicKey = await contractAccount.getPublicKey() ;

An example : https://github.com/PhilippeR26/starknet.js-workshop-typescript/blob/a7b4fe558022d030a1236e9f9df8f05d157f882c/src/scripts/signature/13.signerV5.ts#L65