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IFdcVerification

Interface for verifying Flare Data Connector (FDC) attestation requests.

Sourced from IFdcVerification.sol on GitHub.

Overview​

The IFdcVerification interface provides methods to verify different types of attestations from the Flare Data Connector. Smart contracts can use these verification functions to validate proofs provided by the State Connector system, ensuring the authenticity and integrity of the external data being used.

Verification Functions​

Each verification function takes a proof structure specific to the attestation type and returns a boolean indicating whether the proof is valid.

verifyAddressValidity​

Verifies a proof for an address validity attestation.

function verifyAddressValidity(
    struct IAddressValidity.Proof _proof
) external view returns (
    bool _proved
);

Parameters

  • _proof: The address validity proof structure containing the merkle proof and response data

Returns

  • _proved: Boolean indicating if the proof is valid

verifyBalanceDecreasingTransaction​

Verifies a proof for a balance decreasing transaction attestation.

function verifyBalanceDecreasingTransaction(
    struct IBalanceDecreasingTransaction.Proof _proof
) external view returns (
    bool _proved
);

Parameters

  • _proof: The balance decreasing transaction proof structure

Returns

  • _proved: Boolean indicating if the proof is valid

verifyConfirmedBlockHeightExists​

Verifies a proof that a specified block height exists and is confirmed.

function verifyConfirmedBlockHeightExists(
    struct IConfirmedBlockHeightExists.Proof _proof
) external view returns (
    bool _proved
);

Parameters

  • _proof: The confirmed block height existence proof structure

Returns

  • _proved: Boolean indicating if the proof is valid

verifyEVMTransaction​

Verifies a proof for an Ethereum Virtual Machine transaction.

function verifyEVMTransaction(
    struct IEVMTransaction.Proof _proof
) external view returns (
    bool _proved
);

Parameters

  • _proof: The EVM transaction proof structure

Returns

  • _proved: Boolean indicating if the proof is valid

verifyPayment​

Verifies a proof for a payment transaction.

function verifyPayment(
    struct IPayment.Proof _proof
) external view returns (
    bool _proved
);

Parameters

  • _proof: The payment proof structure

Returns

  • _proved: Boolean indicating if the proof is valid

verifyReferencedPaymentNonexistence​

Verifies a proof that a specific payment with reference did not occur within a given timeframe.

function verifyReferencedPaymentNonexistence(
    struct IReferencedPaymentNonexistence.Proof _proof
) external view returns (
    bool _proved
);

Parameters

  • _proof: The referenced payment nonexistence proof structure

Returns

  • _proved: Boolean indicating if the proof is valid

Usage Example​

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@flare-foundation/flare-smart-contracts-v2/contracts/userInterfaces/IFdcVerification.sol";
import "@flare-foundation/flare-smart-contracts-v2/contracts/userInterfaces/fdc/IAddressValidity.sol";

contract AddressValidator {
    IFdcVerification private fdcVerification;

    constructor(address _fdcVerificationAddress) {
        fdcVerification = IFdcVerification(_fdcVerificationAddress);
    }

    // Function to verify if an address is valid using a provided proof
    function isAddressValid(IAddressValidity.Proof memory proof) external view returns (bool isValid, string memory standardAddress) {
        bool proofVerified = fdcVerification.verifyAddressValidity(proof);

        if (proofVerified) {
            // If proof is valid, extract the response data
            isValid = proof.data.responseBody.isValid;
            standardAddress = proof.data.responseBody.standardAddress;
            return (isValid, standardAddress);
        }

        // If proof verification failed
        return (false, "");
    }
}