Android: Proguard configuration to obfuscate class names and methods

Question

As I know there are some classes which should not be obfuscated and also their names must persisted like 'Activities'. However I want other classes and packages inside my code be renamed. here is build.gradle inside app folder: apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.3"

    defaultConfig {
        applicationId "apt.eve.good.morning"
        minSdkVersion 14
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled true
            shrinkResources true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }


}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:support-v4:23.4.0'
    compile 'com.android.support:appcompat-v7:23.4.0'
    compile 'com.android.support:design:23.4.0'
}

I use this proguard configuration for my application (app\proguard-rules.pro):

-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-useuniqueclassmembernames
-verbose

-keepattributes *Annotation*
-keep public class com.google.vending.licensing.ILicensingService
-keep public class com.android.vending.licensing.ILicensingService

# For native methods, see http://proguard.sourceforge.net/manual/examples.html#native
-keepclasseswithmembernames class * {
    native <methods>;
}

# keep setters in Views so that animations can still work.
# see http://proguard.sourceforge.net/manual/examples.html#beans
-keepclassmembers public class * extends android.view.View {
   void set*(***);
   *** get*();
}
-allowobfuscations class *
# We want to keep methods in Activity that could be used in the XML attribute onClick
-keepclassmembers class * extends android.app.Activity {

   public void *(android.view.View);
}

# For enumeration classes, see http://proguard.sourceforge.net/manual/examples.html#enumerations
-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keepclassmembers class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator CREATOR;
}

-keepclassmembers class **.R$* {
    public static <fields>;
}

# The support library contains references to newer platform versions.
# Don't warn about those in case this app is linking against an older
# platform version.  We know about them, and they are safe.
-dontwarn android.support.**

# Understand the @Keep support annotation.
-keep class android.support.annotation.Keep

-keep @android.support.annotation.Keep class * {*;}

-keepclasseswithmembers class * {
    @android.support.annotation.Keep <methods>;
}

-keepclasseswithmembers class * {
    @android.support.annotation.Keep <fields>;
}

-keepclasseswithmembers class * {
    @android.support.annotation.Keep <init>(...);
}

It do optimization but as I checked inside my classses.dex all class names remained unchanged. So I want to know what I missed in my configuration file which is not obfuscating class/method names?

P.S.1 I have searched several questions but I can't imagine what's wrong here.

P.S.2 I have properly configured my android studio and changes on proguard configuration applies without no problem on my released .apk file.

Answer 1

Based on your gradle file (minifyEnabled=true) and proguard config. You appear to be in good shape already.

To quickly confirm that your app obfuscating your classes, check the resulting mapping.txt file when you make release builds. This file "provides a translation between the original and obfuscated class, method, and field names."

Here is an example of a mapping.txt that obsfucates a hockeyapp library :

net.hockeyapp.android.tasks.AttachmentDownloader -> net.hockeyapp.android.d.a:
    java.util.Queue queue -> a
    boolean downloadRunning -> b
    67:67:net.hockeyapp.android.tasks.AttachmentDownloader getInstance() -> a

Lots more info can be found in the "Shrink Your Code and Resources" article here : https://developer.android.com/studio/build/shrink-code.html

Answer 2

Make sure you check the obfuscated .dex files.

With common gradle build script the build/** folders may contain several unobfuscated versions of .dex/.class files.

Ultimately the resulting .apk/.aar should be obfuscated, so if you are unzipping that one, and the the classes are not obfuscated, then something doesn't work as expected.

As OP noted, it's also important to verify your [disassembly] tools work correctly.

Viewing binary form of .dex from .apk is usually enough to spot [un]obfuscated symbols (try with unobfuscated .class, the symbols are easily readable even in text editor, in obfuscated .dex the chain of symbols like "aa", "ab", ... is often well visible too).

Also running gradle proguard task manually with verbose option on may help to identify if the proguard was run and upon what files.

Answer 3

Do you already changed

minifyEnabled=true

Inside app -> build.gradle?

 buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }