如果证书是从特定的自签名CA签名的,请检查WebViewClient的onReceivedSslError()方法

Question

我想覆盖onReceivedSslError()一个WebViewClient.在这里,我想检查error.getCertificate()证书是否是从自签名CA签名的,只有在这种情况下,才能调用handler.proceed().在伪代码中:

@Override
public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
    SslCertificate serverCertificate = error.getCertificate();

    if (/* signed from my self-signed CA */) {
        handler.proceed();
    }
    else {
        super.onReceivedSslError(view, handler, error);
    }
}

我的CA的公钥保存在名为的BouncyCastle资源中rootca.bks.我能怎么做？

Answer 1

我想你可以尝试如下:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    try {
        WebView webView = (WebView) findViewById(R.id.webView);
        if (webView != null) {
            // Get cert from raw resource...
            CertificateFactory cf = CertificateFactory.getInstance("X.509");
            InputStream caInput = getResources().openRawResource(R.raw.rootca); // stored at \app\src\main\res\raw
            final Certificate certificate = cf.generateCertificate(caInput);
            caInput.close();

            String url = "https://www.yourserver.com";
            webView.setWebViewClient(new WebViewClient() {                    
                @Override
                public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
                    // Get cert from SslError
                    SslCertificate sslCertificate = error.getCertificate();
                    Certificate cert = getX509Certificate(sslCertificate);
                    if (cert != null && certificate != null){
                        try {
                            // Reference: https://developer.android.com/reference/java/security/cert/Certificate.html#verify(java.security.PublicKey)
                            cert.verify(certificate.getPublicKey()); // Verify here...
                            handler.proceed();
                        } catch (CertificateException | NoSuchAlgorithmException | InvalidKeyException | NoSuchProviderException | SignatureException e) {
                            super.onReceivedSslError(view, handler, error);
                            e.printStackTrace();
                        }
                    } else {
                        super.onReceivedSslError(view, handler, error);
                    }
                }
            });

            webView.loadUrl(url);
        }
    } catch (Exception e){
        e.printStackTrace();
    }
}

// credits to @Heath Borders at http://stackoverflow.com/questions/20228800/how-do-i-validate-an-android-net-http-sslcertificate-with-an-x509trustmanager
private Certificate getX509Certificate(SslCertificate sslCertificate){
    Bundle bundle = SslCertificate.saveState(sslCertificate);
    byte[] bytes = bundle.getByteArray("x509-certificate");
    if (bytes == null) {
        return null;
    } else {
        try {
            CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
            return certFactory.generateCertificate(new ByteArrayInputStream(bytes));
        } catch (CertificateException e) {
            return null;
        }
    }
}

如果验证失败,logcat将会有一些信息,例如 java.security.SignatureException: Signature was not verified...

如果成功,这是一个截图:

Answer 2

我认为这应该有效（SSL_IDMISMATCH意思是“主机名不匹配”）。

@Override
public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
    SslCertificate serverCertificate = error.getCertificate();

    if (error.hasError(SSL_UNTRUSTED)) {
        // Check if Cert-Domain equals the Uri-Domain
        String certDomain = serverCertificate.getIssuedTo().getCName();
        if(certDomain.equals(new URL(error.getUrl()).getHost())) {
          handler.proceed();
        }
    }
    else {
        super.onReceivedSslError(view, handler, error);
    }
}

如果“hasError()”不起作用，请尝试 error.getPrimaryError() == SSL_IDMISMATCH

检查所有错误类型的 SslError 文档。

编辑：我在自己的自证书服务器（它是 Xampp）上测试了该功能，但出现错误 #3。这意味着您必须检查error.hasError(SslError.SSL_UNTRUSTED)自签名证书。

Answer 3

基于文档：

getIssuedBy().getDName()您是否尝试过使用SslCertificate 类的方法？此方法返回一个表示“颁发此证书的实体”的字符串。

看看这里：http://developer.android.com/reference/android/net/http/SslCertificate.html#getIssuedBy()

然后您只需要知道自签名时返回的字符串即可。

编辑：我认为如果它是自签名的，那么应该返回空字符串，如果不是，它将返回实体

问候