逆向工程Android应用程序时Smali代码与Java源代码

Question

I'm just looking at android reverse engineering tutorials and I notice that most of them are modifying the smali code instead of the actual java source code after apk has been decompiled, is there a reason for this?

Any help is appreciated.

Thanks

Answer 1

Most of the time, what you get from decompiling is not complete/correct/compilable Java source.

It's just a hard problem to infer (Java) sourcecode from bytecode. Also, certain information from the sourcecode may just be missing from the compiled form, eg names of local variables or parameters, so there's no way to restore them through decompiling.

In comparison, translating byte codes to low level (smali) instructions (and vice versa) is trivial.