Android OkHttp中Https的处理

在android的开发过程中，我们目前常用到的网络请求框架基本都是基于Okhttp，而Https网络通信在APP的开发中也被应用的越来越多，Okhttp默认是支持https网络请求的，但是支持的Https网站必须是CA机构认证了的，对于自签名的网址，还是不能访问的，访问直接抛出如下异常信息：

onFailure: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.

针对https的处理，目前主要有两种方式：

• 客户端默认信任全部证书
• 对自签名网址进行证书的单独处理

客户端默认信任全部证书

这个方式实现起来简单，但是因为信任了全部证书，会有一定的风险！使用者需注意，下面了解一下具体的实现：

1.新建MyTrustManager实现X509TrustManager接口：

public class MyTrustManager implements X509TrustManager {
    @Override
    public void checkClientTrusted(X509Certificate[] chain, String authType) {}

    @Override
    public void checkServerTrusted(X509Certificate[] chain, String authType) {}

    @Override
    public X509Certificate[] getAcceptedIssuers() {return new X509Certificate[0];}
}

2.创建一个方法，用于获取SSLSocketFactory：

private static SSLSocketFactory createSSLSocketFactory() {
        SSLSocketFactory ssfFactory = null;
        try {
            SSLContext sc = SSLContext.getInstance("SSL");
            sc.init(null, new TrustManager[]{new MyTrustManager()}, new SecureRandom());
            ssfFactory = sc.getSocketFactory();
        } catch (Exception e) {
            e.printStackTrace();
        }

        return ssfFactory;
    }

3.OKhttpClient的配置：

static {
     OkHttpClient.Builder builder = new OkHttpClient.Builder();
     builder.connectTimeout(30, TimeUnit.SECONDS);
     builder.sslSocketFactory(createSSLSocketFactory());
     builder.hostnameVerifier(new HostnameVerifier() {
         @Override
         public boolean verify(String hostname, SSLSession session) {
             return true;
         }
     });

     mOkHttpClient = builder.build();
 }

将其封装到Okhttp工具类中，完整代码如下所示：

public class OkhttpUtil {
    public static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");
    public static final MediaType JSON2 = MediaType.parse("application/x-www-form-urlencoded; charset=utf-8");
    private static OkHttpClient mOkHttpClient = new OkHttpClient();

    private static SSLSocketFactory createSSLSocketFactory() {
        SSLSocketFactory ssfFactory = null;
        try {
            SSLContext sc = SSLContext.getInstance("TLS");
            sc.init(null, new TrustManager[]{new MyTrustManager()}, new SecureRandom());
            ssfFactory = sc.getSocketFactory();
        } catch (Exception e) {
            e.printStackTrace();
        }

        return ssfFactory;
    }

    static {
        OkHttpClient.Builder builder = new OkHttpClient.Builder();
        builder.connectTimeout(30, TimeUnit.SECONDS);
        builder.sslSocketFactory(createSSLSocketFactory());
        builder.hostnameVerifier(new HostnameVerifier() {
            @Override
            public boolean verify(String hostname, SSLSession session) {
                return true;
            }
        });

        mOkHttpClient = builder.build();
    }

    public static Response execute(Request request) throws IOException {
        return mOkHttpClient.newCall(request).execute();
    }

    public static void enqueue(Request request, Callback responseCallback) {
        mOkHttpClient.newCall(request).enqueue(responseCallback);
    }

    public static void enqueue(Request request) {
        mOkHttpClient.newCall(request).enqueue(new Callback() {

            @Override
            public void onFailure(Call call, IOException e) {

            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {

            }
        });
    }

    public static String getStringFromServer(String url) throws IOException {
        Request request = new Request.Builder().url(url).build();
        Response response = execute(request);
        if (response.isSuccessful()) {
            String responseUrl = response.body().string();
            return responseUrl;
        } else {
            throw new IOException("Unexpected code " + response);
        }
    }

    private static final String CHARSET_NAME = "UTF-8";

    public static String formatParams(List params) {
        return URLEncodedUtils.format(params, CHARSET_NAME);
    }

    public static String attachHttpGetParams(String url, List params) {
        return url + "?" + formatParams(params);
    }

    public static String attachHttpGetParam(String url, String name, String value) {
        return url + "?" + name + "=" + value;
    }

    public static String post(String url, FormBody body) throws IOException {
        Request request = new Request.Builder()
                .url(url)
                .post(body)
                .build();
        Response response = mOkHttpClient.newCall(request).execute();
        if (response.isSuccessful()) {
            return response.body().string();
        } else {
            throw new IOException("Unexpected code " + response);
        }
    }

    public static String post(String url, JSONObject jsonObject) throws IOException {
        RequestBody body = RequestBody.create(JSON, jsonObject.toString());
        Request request = new Request.Builder()
                .url(url)
                .post(body)
                .build();
        Response response = mOkHttpClient.newCall(request).execute();
        if (response.isSuccessful()) {
            return response.body().string();
        } else {
            throw new IOException("Unexpected code " + response);
        }
    }

    public static String postFrom2Json(String url, JSONObject jsonObject) throws IOException {
        RequestBody body = RequestBody.create(JSON2, jsonObject.toString());
        Request request = new Request.Builder()
                .url(url)
                .post(body)
                .build();
        Response response = mOkHttpClient.newCall(request).execute();
        if (response.isSuccessful()) {
            return response.body().string();
        } else {
            throw new IOException("Unexpected code " + response);
        }
    }

    /**
     * get 方式请求  异步线程中执行
     *
     * @param url 请求地址
     * @return 请求结果
     */
    public static String get(String url) throws IOException {
        Request request = new Request.Builder().url(url).build();
        Response response = mOkHttpClient.newCall(request).execute();
        if (response.isSuccessful()) {
            return response.body().string();
        } else {
            throw new IOException("Unexpected code " + response);
        }
    }

    /**
     * get 方式请求  异步线程中执行
     *
     * @param url 请求地址
     * @return 请求结果
     */
    public static void get(String url, Callback responseCallback) {
        Request request = new Request.Builder().url(url).build();
        mOkHttpClient.newCall(request).enqueue(responseCallback);
    }
}

至此，客户端默认信任全部证书的实现方式就基本实现了。
##WebView中Https的处理
当前很多应用都使用webview加载H5页面，如果服务端采用的是可信CA颁发的证书，在 webView.setWebViewClient(webviewClient) 时重载 WebViewClient的onReceivedSslError() ，如果出现证书错误，直接调用handler.proceed()会忽略错误继续加载证书有问题的页面；如果调用handler.cancel()可以终止加载证书有问题的页面；证书出现问题了，可以提示用户风险，让用户选择加载与否，如果是需要安全级别比较高，可以直接终止页面加载，提示用户网络环境有风险。handler.proceed方法是接受所有的证书，和上文所说的一样当然也是不安全的一种方法。

@Override
    public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
          handler.proceed();
          view.getSettings().setJavaScriptEnabled(true);
     }
            

对自签名网站进行处理

对自签名网站进行处理网络上有较多的介绍，这里推荐鸿洋的Https相关完全解析 当OkHttp遇到Https 文中对处理的方式有详细的介绍，本文不再做单独的说明处理。