从Android FIDO2 SDK v1.1.0开始，safetynet attestation格式已被弃用。相反，Google建议使用Tink库来对FIDO2 attestation进行验证。以下是一个简单的示例代码，展示如何使用Tink验证FIDO2 attestation：

import com.google.crypto.tink.subtle.CommonValidator;
import com.google.crypto.tink.proto.Empty;
import com.google.crypto.tink.proto.TinkPublicKey;
import com.google.crypto.tink.subtle.Validators;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertPath;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class Fido2Verifier {
  // 定义待验证的FIDO2 attestation
  private JSONObject attestation;

  public Fido2Verifier(String base64Attestation) throws JSONException {
    this.attestation = new JSONObject(base64Attestation);
  }

  // 根据Tink库来验证FIDO2 attestation
  public boolean verify() throws Exception {
    // 获取attestation statement
    JSONObject attStmt = attestation.getJSONObject("attStmt");

    // 获取签名算法
    String sigAlg = attStmt.getString("alg");

    // 获取签名数据
    byte[] sigData = Base64.decode(attStmt.getString("sig"));

    // 获取证书链
    JSONArray x5cArray = attStmt.getJSONArray("x5c");
    X509Certificate[] certChain = new X509Certificate[x5cArray.length()];
    CertificateFactory cf = CertificateFactory.getInstance("X.509");
    for (int i = 0; i < x5cArray.length(); i++) {
      byte[] encodedCert = Base64.decode(x5cArray.getString(i));
      certChain[i] = (X509Certificate) cf.generateCertificate(
        new ByteArrayInputStream(encodedCert));
    }

    // 验证证书链
    CertPath certPath  = cf.generateCertPath(Arrays.asList(certChain));
    Validator validator = new SimpleValidator(certPath);
    validator.validate();

    // 从证书中获取公钥
    byte[] publicKeyDer = certChain[0].getPublicKey().getEncoded();
    TinkPublicKey publicKeyProto = TinkPublicKey.newBuilder()
      .setDerPublicKey(ByteString.copyFrom(publicKeyDer))
      .build();

    // 验证签名
    CommonValidator.validateSignature(
      sigData,
      publicKeyProto,
      KeyType.UNKNOWN_PREFIX,
      sigAlg,
      Empty.getDefaultInstance());

    return true;
  }

  //