frida如何抓apk网络包

一 . 埋头分析踩坑路

从系统的角度去寻找hook点，而不是为了抓包而抓包。

1.okhttp调用流程

public static final MediaType JSON= MediaType.get("application/json; charset=utf-8");OkHttpClient client = new OkHttpClient();String post(String url, String json) throws IOException {RequestBody body = RequestBody.create(json, JSON);Request request = new Request.Builder().url(url).post(body).build();try (Response response = client.newCall(request).execute()) {return response.body().string();}}

上面是okhttp官网的一个demo，关键代码就在client.newCall。从此处接口调用开始，终会调用至okhttp框架, okhttp本是sdk，后来aosp已经集成至系统，所以可以归类至框架层。

框架层不详述，主要就是这几个java类:

com.android.okhttp.internal.huc.HttpURLConnectionImplcom.android.okhttp.internal.http.HttpEnginecom.android.okhttp.internal.http.RetryableSinkcom.android.okhttp.internal.http.CacheStrategy$Factory

其实client.newCall终会通过URL获取一个connection

HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();

这里的urlConnection其实就是HttpURLConnectionImpl的实例，该类有getInputStream getOutputStream方法，内部分别会调用HttpEngine的getBufferedRequestBody，getResponse。刚开始我尝试hook过这两个接口，比如hook getResponse后，可以将response打印出来.

之后我发现Request只能打印header，并不能打印body。所以又埋头继续分析，getBufferedRequestBody这个函数刚好可以入手，获取一个sink，最后以RetryableSink为突破点，比如hook 其write函数就可以将body打印出来。write函数对应于app层面的urlConnection.getOutputStream().write。

后来发现一个Request,调用getBufferedReuqestBody函数可能不止一次，所以会有数据重复的问题，后来我又寻找到了CacheStrategy$Factory.get点进行Hook，发现还是有数据重复。发现以上hook均有弊端

• 数据重复

• 非okhttp调用无法抓取

接着又继续从native层的send,sendmsg,write,recv,read打印调用栈。最后折腾了三天，决定放弃治疗，还是采取工具吧。

okhttp流程：sdk接口->okhttp框架->native(libc)

2.分析过程中frida踩到的坑(重点都在注释中)

1. android.util.Log不打印

   var Logd = function Logd(tag, msg) {Java.use("android.util.Log").d(tag, msg);};Logd('http-body-', '11111111111111');//该log不打印Logd('http-body', '11111111111111');//该log打印

2. 匿名内部类获取成员需要反射

   var printRequest = function(request) {var Buffer = Java.use("com.android.okhttp.okio.Buffer");var bodyField = request.getClass().getDeclaredField('body');bodyField.setAccessible(true);if (request == null) return;Logd('http', 'printRequest: request' + request);//var requestBody = request.body();//gadget直接报错var requestBody = bodyField.get(request);var requestBodyClass = requestBody.getClass();var ClassInstanceArray = Java.array('java.lang.Class', []);//var contentLengthMethod = requestBodyClass.getMethod("contentLength");//gadget直接报错var contentLengthMethod = requestBodyClass.getMethod("contentLength", ClassInstanceArray);contentLengthMethod.setAccessible(true);var ObjectInstanceArray = Java.array('java.lang.Object', []);var contentLength = requestBody ? contentLengthMethod.invoke(requestBody, ObjectInstanceArray) : 0;//if (contentLength == 0) contentLength = contentLen;Logd('http', 'printRequest contentLength: ' + contentLength);if (contentLength > 0) {var BufferObj = Buffer.$new();requestBody.writeTo(BufferObj);Logd(TAG, "\nrequest body :\n" + BufferObj.readString() + "\n");}};

3. android.os.Bundle打印，需要将Bundle unparcel

   var printIntentAndExtras = function printIntentAndExtras(intentObj) {if (intentObj == null) return;var Intent = Java.use("android.content.Intent");var Bundle = Java.use("android.os.Bundle");var bundleObj = Intent.getExtras.call(intentObj);if (bundleObj != null) {Bundle.getSize.call(bundleObj, null);//调用getSize即可反序列化}Logd(TAG, ‘printIntentAndExtras ’ + bundleObj);};

踩到的坑其实不只上面的，刚开始也百度过一些frida网络拦截的方案，还仔细的研究了okhttp的Interceptor方案，最后发现app也是用了拦截器，所以就发生冲突，导致无法使用该方案。

也纯粹的分析过app的smali，寻找调用栈以及网络请求，最后，只有几个比较小的收获，可能对读者没有用处，不过记录一下，方便自己以后回忆。

1. java.net.URL拦截

   var URLHook = function() {var URL = Java.use('java.net.URL');URL.openConnection.overload().implementation = function() {var retval = this.openConnection();Logd('URL', openConnection' + retval);return retval;};};//URL.openConnection调用概率比较大，但是不一定对网络进行请求

2. 拦截app调用http请求前使用json的地方，这只是其中之一

   var jsonHook = function() {var xx = Java.use('e.h.a.a');//app smalivar xxa_method = xx.a.overload('org.json.JSONObject', 'java.lang.String', 'java.lang.String');xxa_method.implementation = function(jsonObj, str1, str2) {Logd("json", jsonObj + " str1: " + str1 + " str2" + str2);xxa_method.call(this, jsonObj, str1, str2);}}

3. trace http相关class

   var traceAllHttpClass = function() {Java.perform(function() {Java.enumerateLoadedClasses({onMatch: function(name, handle) {/*"e.h.a.a$a",起初也拦截过app的该混淆类*/if (name.indexOf("com.android.okhttp.Http") != -1 || name.indexOf("com.android.okhttp.Request") != -1|| name.indexOf("com.android.okhttp.internal") != -1) {traceClass(name);//对这三个class进行trace}},onComplete: function() {}});});};

4. Request$Builder拦截

   var BuilderClass = Java.use('com.android.okhttp.Request$Builder')BuilderClass.build.implementation = function () {//LOG('com.android.okhttp.HttpUrl$Builder.build overload', { c: Color.Light.Cyan });//printBacktrace();var retval = this.build();Logd(TAG, "retval:" + retval);printRequest(retval);return retval;}

5. property_get拦截

   var nativePropertyGetAddr = Module.findExportByName(null, '__system_property_get');Interceptor.attach(nativePropertyGetAddr, {onEnter: function onEnter(args) {this._name = args[0].readCString();this._value = args[1];},onLeave: function onLeave(retval) {if (this._name.indexOf("ro.build.id") != -1) {var virtualDevice = getVirtualDevice();if (DEBUG_PROP) Logd(TAG, "__system_property_get fake " + this._name + "=>to " + virtualDevice.build_id);this._value.writeUtf8String(virtualDevice.build_id);}var strFilter = /^ro\./g;if (DEBUG_PROP && this._name.match(strFilter) != null) Logd(TAG, "__system_property_get " + this._name);}});

二 . 设备android_id导致用户过期的处理

var DEBUG_PROP = false;var DEVICE_CONFIG = "/sdcard/.device";function getVirtualDevice() {var nativeOpen = new NativeFunction(Module.findExportByName(‘libc.so’, 'open'), 'int', ['pointer', 'int']);var nativeRead = new NativeFunction(Module.findExportByName('libc.so', 'read'), 'int', ['int', 'pointer', 'int']);var fd = nativeOpen(Memory.allocUtf8String(DEVICE_CONFIG), 0);var mem = Memory.alloc(1024);var readLen = nativeRead(fd, mem, 1024);var json = JSON.parse(mem.readCString(readLen));return json;}Secure.getString.implementation = function () {var retval = this.getString(arguments[0], arguments[1]);if (DEBUG_PROP) Logd(TAG, "Settings.Secure get " + arguments[1] + " val " + retval);if (arguments[1].indexOf("android_id") != -1) {var virtualDevice = getVirtualDevice();return virtualDevice.android_id;}return retval;};

三 . 使用抓包工具fiddle抓包脱坑

1.fiddle代理设置OK，app却无法登陆

分析adb log,进程有 java.security.cert.CertPathValidatorException的打印，之前也看过一些frida拦截抓包绕过证书的帖子。先试一把暴力搜索：

Java.perform(function(){const groups = Java.enumerateMethods('*!verify/u');var classes = null;for(var i in groups){var classes = groups[i]['classes'];for(var i in classes){Java.use(classes[i]['name']).verify.overload('java.lang.String', 'javax.net.ssl.SSLSession').implementation = function() {printBacktrace();LOG("[+] invoke verify", { c: Color.Red });return true;}}}});

调用verify直接暴力返回true，依然无法登陆，报错是同样的ssl问题。百度搜索后找到了答案。apktool解包，然后修改

res/xml/network_security_config.xml<?xml version="1.0" encoding="utf-8"?><network-security-config><base-config cleartextTrafficPermitted="true"><trust-anchors><certificates src="system" /><!--添加fiddle证书可信任<certificates src="user" />--></trust-anchors></base-config></network-security-config>

重打包签名后运行一把，fiddle抓到了包，app也能正常登陆了，这次也是运气好吧，app的ssl校验只有单向app校验，服务器并没有进行校验。

四.结束

从周二下午一直折腾到周五，最后从系统层面的HttpEngine寻找hook点并不是很好的方法，弊端也已明了。所以趁着周日的时间，再试一下各种百度到的方法—-抓包工具，然后一步步将遇到的问题pass掉。

下面是抓到的两个包：

HTTP/1.1 200 OKDate: Sun, 16 Aug 2020 06:27:34 GMTContent-Type: application/jsonContent-Length: 101Connection: keep-aliveGrpc-Metadata-Content-Type: application/grpcVary: OriginVary: Accept-Encoding{"result":{"errno":"OK","errmsg":"成功"},"data":{"version":"xxxxxxxx-351e-40cf-aaa9-3177d6df9b7f"}}-----------------------------------HTTP/1.1 200 OKDate: Sun, 16 Aug 2020 06:27:34 GMTContent-Type: application/jsonContent-Length: 99Connection: keep-aliveGrpc-Metadata-Content-Type: application/grpcVary: OriginVary: Accept-Encoding{"result":{"errno":"OK","errmsg":"成功"},"data":{"nodeToken":"xxxxxxxc24d79f55c0b07beaf50cb566"}}

POST https://tap-xxxxxxx.xxxxxx.com/api/v2/Android/analytics/basic HTTP/1.1Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cjbcjdsabcjvbXVCJ9.eyJ1aWQiOjE4ODMzMDEsInNlY3JldCI6IjAzNzE0M2Y3LTExMTUtNGY2Yi1iNzQxLWUyMjc5ZDM3MGY3MCIsImV4cCI6MTU5NzgxNjQ0MiwiaXNzIjoiZ3Vlc3QgbG9naW4ifQ.W3SiO0-afbhxPITjRinnhyWhZLy1bzZhYexm5VCWklIX-Device-ID: 9xxxxxxx84d4542eX-Loc: ["China","Shanghai","Shanghai","","ChinaUnicom","31.224349","121.4767528","Asia/Shanghai","UTC+8","310000","86","CN","AP","xxx.166.xxx.xxx"]X-App-Version: 2.2.0Content-Type: application/json; charset=utf-8Content-Length: 208Host: xx-xxxx.xxxxxx.comConnection: Keep-AliveAccept-Encoding: gzipUser-Agent: okhttp/4.7.2{"deviceID":"9xxxxxxx84d4542e","model":"V1813BA","systemVersion":"9","version":"2.2.0","location":{"latitude":xx.x99x990990991,"longitude":xxx.26689769073256},"network":{"g2":0,"g3":0,"g4":4,"g5":0,"wifi":4}}-----------------------------------HTTP/1.1 200 OKDate: Sun, 16 Aug 2020 06:27:35 GMTContent-Type: application/jsonContent-Length: 43Connection: keep-aliveGrpc-Metadata-Content-Type: application/grpcVary: OriginVary: Accept-Encoding{"result":{"errno":"OK","errmsg":"成功"}}

以上就是frida如何抓apk网络包的全部内容了，更多与frida如何抓apk网络包相关的内容可以搜索亿速云之前的文章或者浏览下面的文章进行学习哈！相信小编会给大家增添更多知识,希望大家能够支持一下亿速云！