Comments on: Reverse Engineering Android: Disassembling Hello World

By: stanto

stanto — Sat, 14 Sep 2013 09:25:22 +0000

what functions do .local vx / .end local vx and .restart local vx have? Can u give me some advices!

By: Nick Abbott

Nick Abbott — Thu, 29 Aug 2013 13:09:17 +0000

I’m trying to understand some smali and you say this: “overwrite both of our parameter registers. Given we won’t be using either of those registers after setContentView(), this number is appropriate.” BUT, what if you did want to re-use your registers? Would you do:

.line 18
invoke-virtual {p1}, Lcom/test/helloworld/HelloWorldActivity;->getApplicationContext()Landroid/content/Context;

move-result-object v4

const-string v5, “Hacked!”

const/4 v6, 0x0

invoke-static {v4, v5, v6}, Landroid/widget/Toast;->makeText(Landroid/content/Context;Ljava/lang/CharSequence;I)Landroid/widget/Toast;

move-result-object v4

invoke-virtual {v4}, Landroid/widget/Toast;->show()V

Then set .locals to 4 (as we’re using new registers). I think I tried this on something myself and it caused an APK crash!

By: Andy B

Andy B — Mon, 29 Jul 2013 15:04:08 +0000

very cool reverse engineering tut!

By: Java Android Reverse Engineering | Ranjan Kumar

Java Android Reverse Engineering | Ranjan Kumar — Thu, 25 Jul 2013 08:30:29 +0000

[…] Drew following conversion diagram for Java Android reverse engineering. Ref: Smali smali Guide smali syntax highlighting for notepad++ ASM ASMDEX http://jasmin.sourceforge.net http://code.google.com/p/dex2jar/ Reverse Engineering Android: Disassembling Hello World […]

By: Girish

Girish — Mon, 29 Apr 2013 06:17:08 +0000

I want an app which use this reverse enginering concept

By: subha

subha — Fri, 05 Apr 2013 09:18:04 +0000

While trying to re-compile, application shows below error..any idea

C:apktool>apktool b C:HelloWorld
I: Checking whether sources has changed…
I: Smaling…
Exception in thread “main” java.lang.NullPointerException
at org.jf.util.PathUtil.getRelativeFile(PathUtil.java:44)
at org.jf.smali.smaliFlexLexer.getSourceName(smaliFlexLexer.java:2922)
at org.antlr.runtime.CommonTokenStream.getSourceName(CommonTokenStream.j
ava:345)
at org.antlr.runtime.Parser.getSourceName(Parser.java:88)
at org.jf.smali.smaliParser.getErrorHeader(smaliParser.java:358)
at org.antlr.runtime.BaseRecognizer.displayRecognitionError(BaseRecogniz
er.java:192)
at org.antlr.runtime.BaseRecognizer.reportError(BaseRecognizer.java:186)

at org.jf.smali.smaliParser.smali_file(smaliParser.java:736)
at brut.androlib.mod.SmaliMod.assembleSmaliFile(SmaliMod.java:71)
at brut.androlib.src.DexFileBuilder.addSmaliFile(DexFileBuilder.java:43)

at brut.androlib.src.DexFileBuilder.addSmaliFile(DexFileBuilder.java:33)

at brut.androlib.src.SmaliBuilder.buildFile(SmaliBuilder.java:64)
at brut.androlib.src.SmaliBuilder.build(SmaliBuilder.java:48)
at brut.androlib.src.SmaliBuilder.build(SmaliBuilder.java:35)
at brut.androlib.Androlib.buildSourcesSmali(Androlib.java:222)
at brut.androlib.Androlib.buildSources(Androlib.java:179)
at brut.androlib.Androlib.build(Androlib.java:170)
at brut.androlib.Androlib.build(Androlib.java:154)
at brut.apktool.Main.cmdBuild(Main.java:182)
at brut.apktool.Main.main(Main.java:67)

By: AsRaj

AsRaj — Tue, 19 Mar 2013 11:17:41 +0000

For reading out java source take a look at here..
http://stackoverflow.com/questions/1249973/decompiling-dex-into-java-sourcecode

Impressive results with dex2jar and jd-gui!.

By: Abhishek Maurya

Abhishek Maurya — Thu, 14 Feb 2013 15:31:29 +0000

(unable to access apktool.jar) in cmd plz help me

By: CoboltForge

CoboltForge — Sat, 02 Feb 2013 23:28:21 +0000

Nice stuff and the first good writeup of how to read smali we found on the web!

By: shubhangiverma

shubhangiverma — Fri, 23 Nov 2012 10:22:10 +0000

thanks for sharing such a nice tutorial on reverse engineering android