Research On Debugging Android Application Without Source Code Technology

Android system is an embedded operating system used in mobile phone. It is developed and promoted by the U.S. company Google, because of its open source, free, powerful function, it is popular in the world. While the android software is becoming rich, its virus, Trojans, malware is also spreading, the analysis of no source software becomes more and more important. But the no source dynamic analysis software debugging techniques which is the most convenient and practical technology in Windows, Linux systems, is just begin in the Android platform.This paper studies the Android applications without source code dynamic debugging technical, the work is divided into Android java layer no source debugging technology research and Android native layer no source debugging technical research parts.First part, in the java layer debugging, this article aims at the weakness of the offical tools which not supports no source debugging. It studied Android SDK and evey ADT debugging command’s source code, analysed dex file format. It presents a way to combine the JPDA(Java Platform Debugger Architecture) and the dalvik bytes code to debug Android software on the dalvik bytes code. The common personal computer’s dynamic debugging techniques will be ported to Anroid platform with the realization of disassemble, breakpoints, code positioning, set up watchpoints, show registers and other debug features.Second part, in the native layer debugging, this article aims at the problem of the offical ndk which not supports no source debugging. It studied elf file format, jni call, gdbserver working theory, comes up with a way to simulate the environment of native jni call, builds the relation between gdb and so file. It expanded the function of gdb by adding jni rule modify, so file loader, expanded breakpoint. It resolves the problem of loading debugged file, building connecttion, disassembling, making breakpoint, locating source code, controlling jni calls.Compared with dalvikvm terminal debugging, this article’s debug target is apk file, no jar file and dex file; It supports debugging activity not just a terminal program; It supports debugging so file which needs jni call; It needs no compile a new system image, so it is more versatility, can be applied to mobile phones in the market.