Proguard & R8 Dictionaries Generator

Gradle Plugin that generates randomized dictionaries for proguard

Tested on Android Gradle Plugin version 3.5.0 and 3.6.0-alpha10

How to add

Add to your root project's build.gradle:

For Groovy

buildscript {
    repositories {
        maven { 
            url "https://plugins.gradle.org/m2/" 
        }
    }

    dependencies {
        classpath "gradle.plugin.ru.cleverpumpkin.proguard-dictionaries-generator:plugin:1.0.8"
    }
}

For Kotlin DSL

buildscript {
    repositories {
        maven {
            url = uri("https://plugins.gradle.org/m2/")
        }
    }
    dependencies {
        classpath("gradle.plugin.ru.cleverpumpkin.proguard-dictionaries-generator:plugin:1.0.8")
    }
}

Simple configuration

Add to your app module's build.gradle:

For Groovy

apply plugin: "ru.cleverpumpkin.proguard-dictionaries-generator"

proguardDictionaries {
    dictionaryNames = [
        "build/class-dictionary",
        "build/package-dictionary",
        "build/obfuscation-dictionary"
    ]
}

For Kotlin DSL

plugins {
    id("ru.cleverpumpkin.proguard-dictionaries-generator")
}

proguardDictionaries {
    dictionaryNames = listOf(
         "build/class-dictionary",
         "build/package-dictionary",
         "build/obfuscation-dictionary"
      )
}

This setup will generate files class-dictionary.txt, package-dictionary.txt and obfuscation-dictionary.txt in build subdirectory of the module to which the plugin is applied. You can specify any directory relatively to your module's root.

These files will be generated from scratch on every build, so you'll have different dictionaries for each build.

Advanced configuration

For Groovy

proguardDictionaries {
    dictionaryNames = [ "any", "files, "you", "want" ]
    minLineLength 20  // Default value: 10
    maxLineLength 50  // Default value: 30
    linesCountInDictionary 50000  // Default value: 30000
}

For Kotlin DSL

proguardDictionaries {
    dictionaryNames = listOf("any", "files, "you", "want")
    minLineLength = 20  // Default value: 10
    maxLineLength = 50  // Default value: 30
    linesCountInDictionary = 50000  // Default value: 30000
}

How to use plugin output result

Add to your proguard-rules.pro file:

-obfuscationdictionary build/obfuscation-dictionary.txt
-classobfuscationdictionary build/class-dictionary.txt
-packageobfuscationdictionary build/package-dictionary.txt

Program classes number issue

Important: if the final number of classes in *.apk after code shrinking exceeds the linesCountInDictionary value, then all remaining classes will be named by default – starting with first alphabet letters.

Thus, the linesCountInDictionary value must be greater than a number of program classes after code shrinking.

The default size of the dictionary is 30000 lines.

You can find the number of classes in your *.apk by following next steps:

1. While performing build in Android Studio, find the last Optimizing step in the console, e. g. "Optimizing (Step 5/5)".
2. Check the value in line "Final number of program classes".

Or:

1. Drag-n-drop an *.apk file into Android Studio (or open it via menu Build -> Analyze APK...).
2. In APK Analyzer window select classes.dex file. Check the value in the line "This dex file defines X classes..."
3. If more *.dex files present in APK, select each of them and sum up all classes numbers.

Finally, set the value of linesCountInDictionary slightly greater than the resulting number of program classes to keep an extra space for application grow (e. g. if program contains 9802 classes, you can set the value 12000).

Proguard and R8 support

Plugin runs automatically when android plugin executes Proguard or R8 task:

• transformClassesAndResourcesWithR8For{BuiltFlavor}{BuiltType}
• transformClassesAndResourcesWithProguardFor{BuiltFlavor}{BuiltType}

You don't have to specify anything special to get it work.

Dictionary alphabet

Whitespaces, punctuation characters, duplicate words, and comments after a # sign are ignored in dictionaries by Proguard. So generated file could contains any symbols except listed above.

https://www.guardsquare.com/en/products/proguard/manual/usage#obfuscationoptions

Contribution

You need to test plugin locally, right? To build plugin locally uploadArchives gradle task is used that puts plugin into PROJECT_DIR/plugin/pluginRepo folder. Plugin should be added to project's buildscript. First time after cloning the project there's no locally built plugin so plugin should be downloaded from Gradle Plugin portal thus artifactId is gradle.plugin.ru.cleverpumpkin.proguard-dictionaries-generator:plugin After project sync upload plugin locally and set artifactId to ru.cleverpumpkin.proguard-dictionaries-generator:plugin. You can find artifactId here

Authors

Developed by Sergey Chuprin (gregamer@gmail.com)
Supported by Ruslan Arslanov (arslanov.r.f@gmail.com)