android獲取https證書

最近碰到一個問題， 有朋友問android這邊能不能拿到服務器下發的證書，意思就是   自簽名證書的https接口，在請求的時候，也沒有添加自簽名證書進信任列表，直接去發https請求，按照正常https步驟去理解，服務器會返回一個證書，這個證書由於客戶端沒有添加進信任列表，會導致https請求失敗，提示沒有找到信任的證書。  朋友疑問： 在服務器返回證書的時候，能不能強行信任呢？ 

 

針對這個問題， 我在這邊做了測試：

1，由ca簽發的ssl證書，部署一個服務

　　不設置請求的SSLSocketFactory，直接進行https請求

　　　　驗證結果：ok

 

2，自簽名的ssl證書，部署一個服務

　不設置請求的SSLSocketFactory，直接進行https請求

　　　　驗證結果：error，報錯信息   java.security.cert.CertPathValidatorException: Trust anchor for certification path not found，大體意思是沒有找打信任的證書，也就是說這個證書沒有被當前的請求對象所信任。

 

看報錯信息是android系統已經封裝好的證書校驗規則。

 

但是如果不想本地預埋自簽名證書，也不想讓后台暴露證書下載的接口，該怎么辦呢？

我這邊提供一個比較簡陋的方法，通過webview訪問目標https地址，通過webview的onReceivedSslError方法，拿到SslError中的SslCertificate，然后再根據SslCertificate中的saveState方法獲取Bundle，從bundle中拿到"x509-certificate"的字節數組，作為字節流讀取流，通過通用的httpsutils，設置請求對象的sslsocketfactory。

代碼如下：

package com.example.ajaxhttpsdemo;

import android.content.Context;
import android.net.http.SslCertificate;
import android.net.http.SslError;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.webkit.SslErrorHandler;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.KeyManagementException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;

import javax.net.ssl.KeyManager;
import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLException;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
import javax.net.ssl.TrustManagerFactory;
import javax.net.ssl.X509TrustManager;

public class HttpsGetSSLSocketFactory {
    private static SslCertificate sslCertificate;
    public static class SSLParams {
        public SSLSocketFactory sSLSocketFactory;
        public X509TrustManager trustManager;
    }

    public interface Callback{
        void onSuccess(SSLParams sslParams);
        void onError(Exception e);
    }

    public static class MySSLException extends Exception{
        public MySSLException(String str) {
            super(str);
        }
    }

    public static void getSslSocketFactoryOnMainThread(Context context, String httpsUrl, final Callback callback){
        WebView webView = new WebView(context);
        webView.setWebViewClient(new WebViewClient(){
            @Override
            public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
                sslCertificate = error.getCertificate();
                handler.proceed();
                if (sslCertificate!=null){
                    Bundle bundle = SslCertificate.saveState(sslCertificate);
                    byte[] byteArray = bundle.getByteArray("x509-certificate");//從bundle中拿出寫入的x509證書
//                    byte[] byteArray = "123456".getBytes();//測試錯誤證書
                   if (byteArray!=null && byteArray.length>0){
                       try {
                           callback.onSuccess(getSslSocketFactory(new ByteArrayInputStream(byteArray)));
                       } catch (Exception e) {
                           callback.onError(e);
                       }
                   }
                }else {
                    callback.onError(new MySSLException("沒有獲取到服務器證書"));
                }
            }
        });
        webView.getSettings().setJavaScriptEnabled(true);
        webView.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);
        webView.loadUrl(httpsUrl);
    }

    private static SSLParams getSslSocketFactory(InputStream... certificates) throws Exception {
        SSLParams sslParams = new SSLParams();
        try {
            TrustManager[] trustManagers = prepareTrustManager(certificates);
            KeyManager[] keyManagers = prepareKeyManager(null, null);
            SSLContext sslContext = SSLContext.getInstance("TLS");
            X509TrustManager trustManager;
            if (trustManagers != null) {
                trustManager = new MyTrustManager(
                        chooseTrustManager(trustManagers));
            } else {
                throw new Exception("證書錯誤");
            }
            sslContext.init(keyManagers,
                    new TrustManager[]{trustManager}, null);
            sslParams.sSLSocketFactory = sslContext.getSocketFactory();
            sslParams.trustManager = trustManager;
            return sslParams;
        } catch (NoSuchAlgorithmException e) {
            throw new AssertionError(e);
        } catch (KeyManagementException e) {
            throw new AssertionError(e);
        } catch (KeyStoreException e) {
            throw new AssertionError(e);
        } catch (Exception e) {
            throw e;
        }
    }
    private static X509TrustManager chooseTrustManager(
            TrustManager[] trustManagers) {
        for (TrustManager trustManager : trustManagers) {
            if (trustManager instanceof X509TrustManager) {
                return (X509TrustManager) trustManager;
            }
        }
        return null;
    }
    private static TrustManager[] prepareTrustManager(
            InputStream... certificates) {
        if (certificates == null || certificates.length <= 0)
            return null;
        try {
            CertificateFactory certificateFactory = CertificateFactory
                    .getInstance("X.509");
            KeyStore keyStore = KeyStore.getInstance(KeyStore
                    .getDefaultType());
            keyStore.load(null);
            int index = 0;
            for (InputStream certificate : certificates) {
                String certificateAlias = Integer.toString(index++);
                keyStore.setCertificateEntry(certificateAlias,
                        certificateFactory.generateCertificate(certificate));
                try {
                    if (certificate != null)
                        certificate.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            TrustManagerFactory trustManagerFactory;
            trustManagerFactory = TrustManagerFactory
                    .getInstance(TrustManagerFactory.getDefaultAlgorithm());
            trustManagerFactory.init(keyStore);
            return trustManagerFactory.getTrustManagers();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
    private static KeyManager[] prepareKeyManager(InputStream bksFile,
                                                  String password) {
        try {
            if (bksFile == null || password == null)
                return null;
            KeyStore clientKeyStore = KeyStore.getInstance("PKCS12");
            clientKeyStore.load(bksFile, password.toCharArray());
            KeyManagerFactory keyManagerFactory = KeyManagerFactory
                    .getInstance(KeyManagerFactory.getDefaultAlgorithm());
            keyManagerFactory.init(clientKeyStore, password.toCharArray());
            return keyManagerFactory.getKeyManagers();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    private static class MyTrustManager implements X509TrustManager {
        private X509TrustManager defaultTrustManager;
        private X509TrustManager localTrustManager;

        public MyTrustManager(X509TrustManager localTrustManager)
                throws NoSuchAlgorithmException, KeyStoreException {
            TrustManagerFactory var4 = TrustManagerFactory
                    .getInstance(TrustManagerFactory.getDefaultAlgorithm());
            var4.init((KeyStore) null);
            defaultTrustManager = chooseTrustManager(var4
                    .getTrustManagers());
            this.localTrustManager = localTrustManager;
        }

        @Override
        public void checkClientTrusted(X509Certificate[] chain,
                                       String authType) throws CertificateException {
        }

        @Override
        public void checkServerTrusted(X509Certificate[] chain,
                                       String authType) throws CertificateException {
            try {
                defaultTrustManager.checkServerTrusted(chain, authType);
            } catch (CertificateException ce) {
                localTrustManager.checkServerTrusted(chain, authType);
            }
        }

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

　　

留作備用，有錯誤再更正