Android Plus Shell native implementation

Source: Internet
Author: User

This example runs through the Android2.3 simulator only, assuming it is suitable for other models. Please do your own research, but here.

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In the Android apk reinforcement (shell) principle analysis and implementation, the article shelling code is written in the Java layer is very easy to be recognized. A lot of requirements need to transfer the shelling process to the native layer, in fact the idea of transfer is very simple, that is, in the native layer through the JNI call Java layer code.

Before executing, first put the forceapkobj.apk in the /sdcard/payload_odex/folder.

The code has been uploaded to GitHub with the address Https://github.com/jltxgcy/AndroidNativeShell.


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    public class Proxyapplication extends application {@Overrideprotected void Attachbasecontext (Context base) { Super.attachbasecontext (Base);D exloader.load ("Com.jltxgcy.dynamicdex");} @Overridepublic void OnCreate () {Dexloader.run ();}}
Remember the original two methods have a lot of code, here only one line of code to be done.

We look at the Dexloader class again.

public class Dexloader {static {system.loadlibrary ("Dexloader");} public static native void load (String path);p ublic static native void run ();}

The original core shelling code is placed in the native layer.

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The implementation of the JNI is as follows. You can see that essentially the Java layer code is transferred to the native layer via JNI.

static void loadapk (JNIENV * env, Jclass clazz, jstring package) {Jclass Activitythreadclazz;jmethodid currentactivitythr Eadmethodid;jobject activitythreadobject;const Char *packagename;const char *classname;const char *methodName;int Codeoff;jfieldid mpackagesfieldid;jobject mpackagesjobject;jclass Mpackagesclazz;jmethodid getMethodID;jobject Weakreferencejobject;jclass Weakreferencejclazz;jmethodid Getweakmethodid;jobject LoadedApkJObject;jclass Loadedapkjclazz;jfieldid mclassloaderfieldid;jobject mclassloaderjobject;jstring dexPath;jstring dexOptPath;jclass Dexclassloaderclazz;jmethodid Initdexloadermethod;jobject Dexclassloaderjobject;activitythreadclazz = env-> Findclass ("Android/app/activitythread"); Currentactivitythreadmethodid = Env->getstaticmethodid ( Activitythreadclazz, "Currentactivitythread", "() landroid/app/activitythread;"); Activitythreadobject = Env->callstaticobjectmethod (Activitythreadclazz, Currentactivitythreadmethodid); PackageName = Env->getstrIngutfchars (package, jni_false); mpackagesfieldid = Env->getfieldid (Activitythreadclazz, "Mpackages", "Ljava/util /hashmap; "); Mpackagesjobject = Env->getobjectfield (Activitythreadobject, mpackagesfieldid); mpackagesclazz = env-> Getobjectclass (mpackagesjobject); getmethodid = Env->getmethodid (Mpackagesclazz, "Get", "(Ljava/lang/object;) Ljava/lang/object; "); Weakreferencejobject = Env->callobjectmethod (Mpackagesjobject, Getmethodid, package); Weakreferencejclazz = env- >getobjectclass (weakreferencejobject); getweakmethodid = Env->getmethodid (Weakreferencejclazz, "Get", "() L Java/lang/object; "); Loadedapkjobject = Env->callobjectmethod (Weakreferencejobject, getweakmethodid); loadedApkJClazz = env-> Getobjectclass (loadedapkjobject); mclassloaderfieldid = Env->getfieldid (Loadedapkjclazz, "MClassLoader", "Ljava/ Lang/classloader; "); Mclassloaderjobject = Env->getobjectfield (Loadedapkjobject, mclassloaderfieldid);d Expath = Env->NewStringUTF ( "/sdcard/payload_odex/forceapkobj.apk ");d Exoptpath = Env->newstringutf ("/sdcard/payload_odex/");d Exclassloaderclazz = Env->findclass ("Dalvik/system/dexclassloader"); Initdexloadermethod = Env->getmethodid (DexClassLoaderClazz, "<init>", "(ljava/lang/string; ljava/lang/string; ljava/lang/string; Ljava/lang/classloader;) V ");d Exclassloaderjobject = Env->newobject (Dexclassloaderclazz,initdexloadermethod, Dexpath, Dexoptpath, NULL, Mclassloaderjobject); Env->setobjectfield (Loadedapkjobject, Mclassloaderfieldid, Dexclassloaderjobject); ALOGD ("packagename:%s", PackageName);} static void Run (JNIENV * env, Jclass clazz) {jclass Activitythreadclazz;jmethodid currentactivitythreadmethodid;jobject Activitythreadobject;jfieldid Mboundapplicationfieldid;jobject Mboundapplicationjobject;jclass Mboundapplicationclazz;jfieldid minfofieldid;jobject minfojobject;jclass Minfoclazz;jfieldid MApplicationFieldID; Jobject Mapplicationjobject;jfieldid Minitialapplicationfieldid;jobject MinitialapplicationjobJect;jfieldid Mallapplicationsfieldid;jobject Mallapplicationsjobject;jclass Mallapplicationsclazz;jmethodid Removemethodid;jfieldid mapplicationinfofieldid;jobject Mapplicationinfojobject;jclass MApplicationInfoClazz; Jfieldid mbindapplicationinfofieldid;jobject Mbindapplicationinfojobject;jclass MBindApplicationInfoClazz; Jfieldid classnamefieldid;jfieldid mbindclassnamefieldid;jstring Applicationname;jmethodid MakeApplicationMethodID ; Jobject applicationjobject;jclass Applicationclazz;jmethodid oncreatemethodid;activitythreadclazz = env-> Findclass ("Android/app/activitythread"); Currentactivitythreadmethodid = Env->getstaticmethodid ( Activitythreadclazz, "Currentactivitythread", "() landroid/app/activitythread;"); Activitythreadobject = Env->callstaticobjectmethod (Activitythreadclazz, Currentactivitythreadmethodid); Mboundapplicationfieldid = Env->getfieldid (Activitythreadclazz, "mboundapplication", "Landroid/app/ Activitythread$appbinddata; "); Mboundapplicationjobject = Env->getobjectfield (Activitythreadobject, mboundapplicationfieldid); mboundapplicationclazz = env-> Getobjectclass (mboundapplicationjobject); minfofieldid = Env->getfieldid (mboundapplicationclazz, "info", " landroid/app/loadedapk; "); Minfojobject = Env->getobjectfield (Mboundapplicationjobject, minfofieldid); minfoclazz = Env->GetObjectClass ( Minfojobject); mapplicationfieldid = Env->getfieldid (Minfoclazz, "mapplication", "landroid/app/application;"); Mapplicationjobject = Env->getobjectfield (Minfojobject, Mapplicationfieldid); Env->setobjectfield ( Minfojobject, Mapplicationfieldid, NULL); minitialapplicationfieldid = Env->getfieldid (ActivityThreadClazz, " Minitialapplication "," landroid/app/application; "); Minitialapplicationjobject = Env->getobjectfield (Activitythreadobject, Minitialapplicationfieldid); Mallapplicationsfieldid = Env->getfieldid (Activitythreadclazz, "mallapplications", "Ljava/util/ArrayList;"); Mallapplicationsjobject = Env->getobjectfield (activityThreadobject, mallapplicationsfieldid); mallapplicationsclazz = Env->getobjectclass (MAllApplicationsJObject); Removemethodid = Env->getmethodid (Mallapplicationsclazz, "Remove", "(Ljava/lang/object;) Z"); Jboolean isTrue = Env->callbooleanmethod (Mallapplicationsjobject, Removemethodid, Minitialapplicationjobject); Mapplicationinfofieldid = Env->getfieldid (Minfoclazz, "Mapplicationinfo", "landroid/content/pm/applicationinfo;"); Mapplicationinfojobject = Env->getobjectfield (Minfojobject, mapplicationinfofieldid); MApplicationInfoClazz = Env->getobjectclass (mapplicationinfojobject); mbindapplicationinfofieldid = Env->getfieldid ( Mboundapplicationclazz, "AppInfo", "landroid/content/pm/applicationinfo;"); Mbindapplicationinfojobject = Env->getobjectfield (Mboundapplicationjobject, Mbindapplicationinfofieldid); Mbindapplicationinfoclazz = Env->getobjectclass (mbindapplicationinfojobject); classnamefieldid = env-> Getfieldid (Mapplicationinfoclazz, "ClassName", "ljava/lang/string; "); Mbindclassnamefieldid = Env->getfieldid (Mbindapplicationinfoclazz, "ClassName", "ljava/lang/string;"); ApplicationName = Env->newstringutf ("com.example.forceapkobj.MyApplication"); Env->setobjectfield ( Mapplicationinfojobject, Classnamefieldid, ApplicationName); Env->setobjectfield (MBindApplicationInfoJObject, Mbindclassnamefieldid, applicationname); makeapplicationmethodid = Env->getmethodid (MInfoClazz, "makeApplication "," (zlandroid/app/instrumentation;) landroid/app/application; "); Applicationjobject = Env->callobjectmethod (Minfojobject, Makeapplicationmethodid, JNI_FALSE, NULL);env-> Setobjectfield (Activitythreadobject, Minitialapplicationfieldid, Applicationjobject); Applicationclazz = Env->getobjectclass (applicationjobject); oncreatemethodid = Env->getmethodid ( Applicationclazz, "OnCreate", "() V"); Env->callvoidmethod (Applicationjobject, oncreatemethodid);} Jniexport void Jnicall java_com_jltxgcy_dynamicdex_dexloader_load (jnienv * env, Jclass Clazz, jstring PackageName) {loadapk (env, Clazz, PackageName); ALOGD ("Java_com_jltxgcy_dynamicdex_dexloader_load");} Jniexport void Jnicall Java_com_jltxgcy_dynamicdex_dexloader_run (jnienv * env, Jclass clazz) {run (env, clazz); ALOGD ("Java_com_jltxgcy_dynamicdex_dexloader_run");}

Android Plus Shell native implementation

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