java - Java 如何验证证书是否为 EV 证书？

Question

考虑以下示例代码，它使用 TrustManager 记录传出连接是否使用了有效证书(但在所有情况下都接受连接):

import java.security.*;
import java.security.cert.*;
import javax.net.ssl.*;

public class CertChecker implements X509TrustManager {

    private final X509TrustManager defaultTM;

    public CertChecker() throws GeneralSecurityException {
        TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
        tmf.init((KeyStore)null);
        defaultTM = (X509TrustManager) tmf.getTrustManagers()[0];
    }

    public void checkServerTrusted(X509Certificate[] certs, String authType) {
        if (defaultTM != null) {
            try {
                defaultTM.checkServerTrusted(certs, authType);
                System.out.println("Certificate valid");
            } catch (CertificateException ex) {
                System.out.println("Certificate invalid: " + ex.getMessage());
            }
        }
    }

    public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {}
    public X509Certificate[] getAcceptedIssuers() { return null;}

    public static void main(String[] args) throws Exception {
        SSLContext sc = SSLContext.getInstance("SSL");
        sc.init(null, new TrustManager[] {new CertChecker()}, new SecureRandom());
        SSLSocketFactory ssf = (SSLSocketFactory) sc.getSocketFactory();
        ((SSLSocket)ssf.createSocket(args[0], 443)).startHandshake();
    }
}

我必须在 checkClientTrusted 方法中做什么来检查该证书是扩展验证证书(现代浏览器中的绿色地址栏)还是普通证书(黄色地址栏)？

编辑:

我正在尝试让 CertPathValidator 工作，但不知何故我只得到关于证书不是 CA 证书的异常...有什么想法吗？

edit2: 使用 PKIXParameters 而不是 PKIXBuilderParameters

private boolean isEVCertificate(X509Certificate[] certs, String authType) {
    try {
        CertPath cp = new X509CertPath(Arrays.asList(certs));
        KeyStore ks = KeyStore.getInstance("JKS");
        ks.load(new FileInputStream(new File(System.getProperty("java.home"), "lib/security/cacerts")), null);
        PKIXParameters cpp = new PKIXParameters(ks);
        cpp.setRevocationEnabled(false);
        CertPathValidator cpv = CertPathValidator.getInstance("PKIX");          
        PKIXCertPathValidatorResult res = (PKIXCertPathValidatorResult) cpv.validate(cp, cpp);
        System.out.println(res.getTrustAnchor().getCAName());
        System.out.println(res.getPolicyTree().getValidPolicy());
        System.out.println(cp);
        return false;
    } catch (Exception ex) {
        ex.printStackTrace();
        return false;
    }
}

我正在针对真实世界的 EV 证书进行测试。该代码现在适用于 www.paypal.com(从某种意义上说它不会抛出异常)，但不适用于 banking.dkb.de。 :-(

但即使使用 Paypal.com，信任 anchor getCAName 也会返回 null，所以我如何知道它是针对哪个 CA 进行验证的，以便我可以查找正确的 EV 策略？

Answer 1

首先，您需要一张发行人名称及其对应的 EV 保单标识符表。

当 CA 颁发证书时，他们可以记录颁发证书所依据的策略。发行人为此政策分配的标识符，因此您需要一份发行人及其 EV 政策列表。

然后您需要从服务器证书中获取策略。 Refer to RFC 5280, § 4.1.2.4详细了解一般政策及其运作方式。

您需要验证证书链以获得 PKIXCertPathValidatorResult。 结果的一部分是 policy tree.您可以浏览策略树以确定它是否包含目标证书颁发者的 EV 策略。

---

下面是检查证书路径结果的详细示例。

private static final Map<X500Principal, String> policies = new HashMap<X500Principal, String>();

static {
  /* 
   * It would make sense to populate this map from Properties loaded through 
   * Class.getResourceAsStream().
   */
  policies.put(
    new X500Principal("OU=Class 3 Public Primary Certification Authority,O=VeriSign\\, Inc.,C=US"), 
    "2.16.840.1.113733.1.7.23.6"
  );
  // ...
}

static boolean isEV(PKIXCertPathValidatorResult result)
{
  /* Determine the policy to look for. */
  X500Principal root = result.getTrustAnchor().getTrustedCert().getSubjectX500Principal();
  String policy = policies.get(root);
  if (policy == null)
    /* The EV policy for this issuer is unknown (or there is none). */
    return false;
  /* Traverse the tree, looking at its "leaves" to see if the end-entity 
   * certificate was issued under the corresponding EV policy. */
  PolicyNode tree = result.getPolicyTree();
  Deque<PolicyNode> stack = new ArrayDeque<PolicyNode>();
  stack.push(tree);
  while (!stack.isEmpty()) {
    PolicyNode current = stack.pop();
    Iterator<? extends PolicyNode> children = current.getChildren();
    int leaf = stack.size();
    while (children.hasNext())
      stack.push(children.next());
    if (stack.size() == leaf) {
      /* If the stack didn't grow, there were no "children". I.e., the 
       * current node is a "leaf" node of the policy tree. */
      if (current.getValidPolicy().equals(policy))
        return true;
    }
  }
  /* The certificate wasn't issued under the authority's EV policy. */
  return false;
}