status-im/status-go

package ens

import (
    "bytes"
    "context"
    "crypto/elliptic"
    "encoding/hex"
    "math/big"
    "time"

    ens "github.com/wealdtech/go-ens/v3"
    "go.uber.org/zap"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/ethclient"

    "github.com/status-im/status-go/eth-node/crypto"
    enstypes "github.com/status-im/status-go/eth-node/types/ens"
)

const (
    contractQueryTimeout = 5000 * time.Millisecond
)

type Verifier struct {
    logger *zap.Logger
}

// NewVerifier returns a Verifier attached to the specified logger
func NewVerifier(logger *zap.Logger) *Verifier {
    return &Verifier{logger: logger}
}

func (m *Verifier) ReverseResolve(address common.Address, rpcEndpoint string) (string, error) {
    ctx, cancel := context.WithTimeout(context.Background(), contractQueryTimeout)
    defer cancel()

    ethClient, err := ethclient.DialContext(ctx, rpcEndpoint)
    if err != nil {
        return "", err
    }
    return ens.ReverseResolve(ethClient, address)
}

func (m *Verifier) verifyENSName(ensInfo enstypes.ENSDetails, ethclient *ethclient.Client) enstypes.ENSResponse {
    publicKeyStr := ensInfo.PublicKeyString
    ensName := ensInfo.Name
    m.logger.Info("Resolving ENS name", zap.String("name", ensName), zap.String("publicKey", publicKeyStr))
    response := enstypes.ENSResponse{
        Name:            ensName,
        PublicKeyString: publicKeyStr,
        VerifiedAt:      time.Now().Unix(),
    }

    expectedPubKeyBytes, err := hex.DecodeString(publicKeyStr)
    if err != nil {
        response.Error = err
        return response
    }

    publicKey, err := crypto.UnmarshalPubkey(expectedPubKeyBytes)
    if err != nil {
        response.Error = err
        return response
    }

    // Resolve ensName
    resolver, err := ens.NewResolver(ethclient, ensName)
    if err != nil {
        m.logger.Error("error while creating ENS name resolver", zap.String("ensName", ensName), zap.Error(err))
        response.Error = err
        return response
    }
    x, y, err := resolver.PubKey()
    if err != nil {
        m.logger.Error("error while resolving public key from ENS name", zap.String("ensName", ensName), zap.Error(err))
        response.Error = err
        return response
    }

    // Assemble the bytes returned for the pubkey
    pubKeyBytes := elliptic.Marshal(crypto.S256(), new(big.Int).SetBytes(x[:]), new(big.Int).SetBytes(y[:]))

    response.PublicKey = publicKey
    response.Verified = bytes.Equal(pubKeyBytes, expectedPubKeyBytes)
    return response
}

// CheckBatch verifies that a registered ENS name matches the expected public key
func (m *Verifier) CheckBatch(ensDetails []enstypes.ENSDetails, rpcEndpoint, contractAddress string) (map[string]enstypes.ENSResponse, error) {
    ctx, cancel := context.WithTimeout(context.Background(), contractQueryTimeout)
    defer cancel()

    ch := make(chan enstypes.ENSResponse)
    response := make(map[string]enstypes.ENSResponse)

    ethclient, err := ethclient.DialContext(ctx, rpcEndpoint)
    if err != nil {
        return nil, err
    }

    for _, ensInfo := range ensDetails {
        go func(info enstypes.ENSDetails) { ch <- m.verifyENSName(info, ethclient) }(ensInfo)
    }

    for range ensDetails {
        r := <-ch
        response[r.PublicKeyString] = r
    }
    close(ch)

    return response, nil
}