遇到的问题
由于Android7以后google更改了安全策略，用户添加的CA证书不能再用于安全连接，意思就是你自己安装的Charles的证书也没有卵用了。当我们抓HTTPS的包时候会出现下面的问题
2019-02-11 14:27:12.232 8913-8954/? W/System.err: javax.net.ssl.SSLHandshakeException: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.
2019-02-11 14:27:12.232 8913-8954/? W/System.err: at com.android.org.conscrypt.OpenSSLSocketImpl.startHandshake(OpenSSLSocketImpl.java:361)
2019-02-11 14:27:12.232 8913-8954/? W/System.err: at com.android.okhttp.Connection.connectTls(Connection.java:235)
2019-02-11 14:27:12.232 8913-8954/? W/System.err: at com.android.okhttp.Connection.connectSocket(Connection.java:199)
2019-02-11 14:27:12.233 8913-8954/? W/System.err: at com.android.okhttp.Connection.connect(Connection.java:172)
2019-02-11 14:27:12.233 8913-8954/? W/System.err: at com.android.okhttp.Connection.connectAndSetOwner(Connection.java:367)
2019-02-11 14:27:12.233 8913-8954/? W/System.err: at com.android.okhttp.OkHttpClient$1.connectAndSetOwner(OkHttpClient.java:130)
2019-02-11 14:27:12.233 8913-8954/? W/System.err: at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:329)
2019-02-11 14:27:12.233 8913-8954/? W/System.err: at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:246)
2019-02-11 14:27:12.233 8913-8954/? W/System.err: at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:457)
2019-02-11 14:27:12.233 8913-8954/? W/System.err: at com.android.okhttp.internal.huc.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:126)
2019-02-11 14:27:12.233 8913-8954/? W/System.err: at com.android.okhttp.internal.huc.DelegatingHttpsURLConnection.connect(DelegatingHttpsURLConnection.java:89)
2019-02-11 14:27:12.233 8913-8954/? W/System.err: at com.android.okhttp.internal.huc.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java)
2019-02-11 14:27:12.233 8913-8954/? W/System.err: at com.example.android.sdk.http.HttpRequest.execute(HttpRequest.java:73)
2019-02-11 14:27:12.233 8913-8954/? W/System.err: at com.example.android.sdk.http.HttpRequest$1.run(HttpRequest.java:110)
2019-02-11 14:27:12.233 8913-8954/? W/System.err: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
2019-02-11 14:27:12.233 8913-8954/? W/System.err: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
2019-02-11 14:27:12.233 8913-8954/? W/System.err: at java.lang.Thread.run(Thread.java:761)
2019-02-11 14:27:12.235 8913-8954/? W/System.err: Caused by: java.security.cert.CertificateException: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.
2019-02-11 14:27:12.235 8913-8954/? W/System.err: at com.android.org.conscrypt.TrustManagerImpl.verifyChain(TrustManagerImpl.java:563)
2019-02-11 14:27:12.235 8913-8954/? W/System.err: at com.android.org.conscrypt.TrustManagerImpl.checkTrustedRecursive(TrustManagerImpl.java:444)
2019-02-11 14:27:12.235 8913-8954/? W/System.err: at com.android.org.conscrypt.TrustManagerImpl.checkTrustedRecursive(TrustManagerImpl.java:508)
2019-02-11 14:27:12.235 8913-8954/? W/System.err: at com.android.org.conscrypt.TrustManagerImpl.checkTrusted(TrustManagerImpl.java:401)
2019-02-11 14:27:12.235 8913-8954/? W/System.err: at com.android.org.conscrypt.TrustManagerImpl.checkTrusted(TrustManagerImpl.java:375)
2019-02-11 14:27:12.235 8913-8954/? W/System.err: at com.android.org.conscrypt.TrustManagerImpl.getTrustedChainForServer(TrustManagerImpl.java:304)
2019-02-11 14:27:12.235 8913-8954/? W/System.err: at android.security.net.config.NetworkSecurityTrustManager.checkServerTrusted(NetworkSecurityTrustManager.java:94)
2019-02-11 14:27:12.235 8913-8954/? W/System.err: at android.security.net.config.RootTrustManager.checkServerTrusted(RootTrustManager.java:88)
2019-02-11 14:27:12.236 8913-8954/? W/System.err: at com.android.org.conscrypt.Platform.checkServerTrusted(Platform.java:178)
2019-02-11 14:27:12.236 8913-8954/? W/System.err: at com.android.org.conscrypt.OpenSSLSocketImpl.verifyCertificateChain(OpenSSLSocketImpl.java:596)
2019-02-11 14:27:12.236 8913-8954/? W/System.err: at com.android.org.conscrypt.NativeCrypto.SSL_do_handshake(Native Method)
2019-02-11 14:27:12.236 8913-8954/? W/System.err: at com.android.org.conscrypt.OpenSSLSocketImpl.startHandshake(OpenSSLSocketImpl.java:357)
2019-02-11 14:27:12.236 8913-8954/? W/System.err: ... 16 more
2019-02-11 14:27:12.236 8913-8954/? W/System.err: Caused by: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.
2019-02-11 14:27:12.236 8913-8954/? W/System.err: ... 28 more
解决办法一
该方法针对未Root的设备，直接参看Android官方的文档developer.android.com/training/ar… 但是这个办法有个局限就是只能抓取自己APP的包，无法抓取第三方APP，而且操作麻烦。
解决办法二
本文章主要讲的是该方法，一个一劳永逸的方法，就是将Charles的证书安装为系统证书。
1. 确保手机已经Root
至于Root的方法我就不再累述
2. 下载证书
根据Charles的help浏览chls.pro/ssl下载证书，你可以在设备上下载后adb pull到电脑上，也可以直接用电脑浏览器下载。
3. 重命名证书
系统证书在目录/system/etc/security/cacerts/下，我们看到
<Certificate_Hash>.<Number>,文件名是一个Hash值，而后缀是一个数字。后缀名的数字是为了防止文件名冲突的，比如如果两个证书算出的Hash值是一样的话，那么一个证书的后缀名数字可以设置成0，而另一个证书的后缀名数字可以设置成1.
我们用下面的命令计算出证书文件的Hash值
openssl x509 -subject_hash_old -in <Certificate_File>
4. 上传证书
我们将重命名好的证书adb push到/sdcard/Download，然后将其复制到/system/etc/security/cacerts/文件夹。
mount -o rw,remount /system命令将system分区挂在为可读写。还是失败请依次执行下面命名：
adb root
adb disable-verity
adb reboot
adb remount
adb shell
mount -o rw,remount /system
复制好后将文件权限更改为644，并重启设备
5. 验证结果
设置》安全》信任的凭证，我们可以看到
