时间:2021-08-23 09:26:31 | 栏目:Android代码 | 点击:次
前言
很多公司考虑到安全问题,项目中都采用https加密协议进行数据传输。但是一些公司又不想花一笔钱去CA申请证书,所以就采用自签名的证书。
OkHttp默认是可以访问通过CA认证的HTTPS链接,例如百度首页也是https链接(https://www.baidu.com/)。但是如果是你们公司自签名(即自己用keytool生成的证书,而不是采用通过CA认证的证书)的服务器,OkHttp是无法访问的,例如访问12306网站(https://kyfw.12306.cn/otn/),会报如下错误:
HTTPS的工作原理
HTTPS在传输数据之前需要客户端(浏览器)与服务端(网站)之间进行一次握手,在握手过程中将确立双方加密传输数据的密码信息。握手过程的简单描述如下:
握手过程中如果有任何错误,都会使加密连接断开,从而阻止了隐私信息的传输。
使用OKHTTP请求自签名的https服务器数据
以下我们使用12306网站为例
1. 首先去12306网站首页下载证书 http://www.12306.cn/
2. 将下载的证书srca.cer放到工程的assets文件夹下。
3. 添加HTTPS工具类
package com.alpha58.okhttp; import android.content.Context; import java.io.IOException; import java.io.InputStream; import java.security.GeneralSecurityException; import java.security.KeyStore; import java.security.cert.Certificate; import java.security.cert.CertificateFactory; import java.util.Arrays; import java.util.Collection; import javax.net.ssl.KeyManagerFactory; import javax.net.ssl.SSLContext; import javax.net.ssl.SSLSocketFactory; import javax.net.ssl.TrustManager; import javax.net.ssl.TrustManagerFactory; import javax.net.ssl.X509TrustManager; import okhttp3.OkHttpClient; /** * Created by admin on 2017/03/12. */ public final class HTTPSUtils { private OkHttpClient client; public Context mContext; /** * 获取OkHttpClient实例 * @return */ public OkHttpClient getInstance() { return client; } /** * 初始化HTTPS,添加信任证书 * @param context */ public HTTPSUtils(Context context) { mContext = context; X509TrustManager trustManager; SSLSocketFactory sslSocketFactory; final InputStream inputStream; try { inputStream = mContext.getAssets().open("srca.cer"); // 得到证书的输入流 try { trustManager = trustManagerForCertificates(inputStream);//以流的方式读入证书 SSLContext sslContext = SSLContext.getInstance("TLS"); sslContext.init(null, new TrustManager[]{trustManager}, null); sslSocketFactory = sslContext.getSocketFactory(); } catch (GeneralSecurityException e) { throw new RuntimeException(e); } client = new OkHttpClient.Builder() .sslSocketFactory(sslSocketFactory, trustManager) .build(); } catch (IOException e) { e.printStackTrace(); } } /** * 以流的方式添加信任证书 */ /** * Returns a trust manager that trusts {@code certificates} and none other. HTTPS services whose * certificates have not been signed by these certificates will fail with a {@code * SSLHandshakeException}. * <p> * <p>This can be used to replace the host platform's built-in trusted certificates with a custom * set. This is useful in development where certificate authority-trusted certificates aren't * available. Or in production, to avoid reliance on third-party certificate authorities. * <p> * <p> * <h3>Warning: Customizing Trusted Certificates is Dangerous!</h3> * <p> * <p>Relying on your own trusted certificates limits your server team's ability to update their * TLS certificates. By installing a specific set of trusted certificates, you take on additional * operational complexity and limit your ability to migrate between certificate authorities. Do * not use custom trusted certificates in production without the blessing of your server's TLS * administrator. */ private X509TrustManager trustManagerForCertificates(InputStream in) throws GeneralSecurityException { CertificateFactory certificateFactory = CertificateFactory.getInstance("X.509"); Collection<? extends Certificate> certificates = certificateFactory.generateCertificates(in); if (certificates.isEmpty()) { throw new IllegalArgumentException("expected non-empty set of trusted certificates"); } // Put the certificates a key store. char[] password = "password".toCharArray(); // Any password will work. KeyStore keyStore = newEmptyKeyStore(password); int index = 0; for (Certificate certificate : certificates) { String certificateAlias = Integer.toString(index++); keyStore.setCertificateEntry(certificateAlias, certificate); } // Use it to build an X509 trust manager. KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance( KeyManagerFactory.getDefaultAlgorithm()); keyManagerFactory.init(keyStore, password); TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance( TrustManagerFactory.getDefaultAlgorithm()); trustManagerFactory.init(keyStore); TrustManager[] trustManagers = trustManagerFactory.getTrustManagers(); if (trustManagers.length != 1 || !(trustManagers[0] instanceof X509TrustManager)) { throw new IllegalStateException("Unexpected default trust managers:" + Arrays.toString(trustManagers)); } return (X509TrustManager) trustManagers[0]; } /** * 添加password * @param password * @return * @throws GeneralSecurityException */ private KeyStore newEmptyKeyStore(char[] password) throws GeneralSecurityException { try { KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType()); // 这里添加自定义的密码,默认 InputStream in = null; // By convention, 'null' creates an empty key store. keyStore.load(in, password); return keyStore; } catch (IOException e) { throw new AssertionError(e); } } }
4.代码中请求
public void getHttpsHtml(View view) { Request request = new Request.Builder() .url("https://kyfw.12306.cn/otn/") .build(); HTTPSUtils httpsUtils = new HTTPSUtils(this); httpsUtils.getInstance().newCall(request).enqueue(new Callback() { @Override public void onFailure(Call call, IOException e) { System.out.println("--------------onFailure--------------" + e.toString()); } @Override public void onResponse(Call call, Response response) throws IOException { System.out.println("--------------onResponse--------------" + response.body().string()); } }); }
5. 最后能打印出这些信息就说明请求成功啦!
注意:别忘了加权限和依赖okhttp库