connect-to-blocto-wallet.md

description
Connecting to wallet is being called authentication or authn in FCL

Connect to Blocto Wallet

{% hint style="warning" %} Make sure you have set the configuration in Getting Started first. {% endhint %}

There are two different ways to connect wallet:

• Normal log in and retrieve user's flow account address.

import FCL_SDK

Task {
    let address = try await fcl.login()
}

• Log in with account proof data to retrieve user's flow account address along with account proof.

If dApp chooses to ask user for user's authentication in this way, and the user approves the signing of message data, it will return user's flow account address with accountProofData that can be used to prove a user controls an on-chain account.

import FCL_SDK

let accountProofData = FCLAccountProofData(
    appId: "Here you can specify your app name.",
    nonce: "75f8587e5bd5f9dcc9909d0dae1f0ac5814458b2ae129620502cb936fde7120a" // minimum 32-byte random nonce as a hex string.
)
Task {
    do {
        let address = try await fcl.authanticate(accountProofData: accountProofData)
    } catch {
        // handle error here
    }
}

fcl.authanticate is also called behide fcl.login() with accountProofData set to nil.

Both methods above store address under fcl.currentUser , to get user address just simply call as below.

if let userWalletAddress = fcl.currentUser?.address {
    // do some stuff here.
}

To get user address or account proof after user authenticated, just simply call as below.

if let accountProof = fcl.currentUser?.accountProof {
    // verify account proof here.
}

Verify account proof

Cadence has a built-in function called verify that will verify a signature against a Flow account given the account address.

FCL-Swift includes a utility function in AppUtilities, verifyAccountProof, for verifying one or more account proof signatures against an account's public key on the Flow blockchain.

import FCL_SDK

guard let accountProof = fcl.currentUser?.accountProof else {
    // handle error here
    return
}

Task {
    do {
        let valid = try await AppUtilities.verifyAccountProof(
            appIdentifier: "Here you can specify your app name.",
            accountProofData: accountProof,
            fclCryptoContract: Address(hexString: BLOCTO_FCLCRYPTO_CONTRACT_ADDRESS)
        )
    } catch {
        // handle error here
    }
}

BLOCTO_FCLCRYPTO_CONTRACT_ADDRESS can be found here

{% hint style="warning" %} input parameter appIdentifier should be exactly same with FCLAccountProofData 's appId above. They should all be a human readable string. {% endhint %}