OoAmosoO / AndResGuard

proguard resource for Android by wechat team

AndResGuard

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AndResGuard is a tooling for reducing your apk size, it works like the ProGuard for Java source code, but only aim at the resource files. It changes res/drawable/wechat to r/d/a, and renames the resource file wechat.png to a.png. Finally, it repackages the apk with 7zip, which can reduce the package size obviously.

AndResGuard is fast, and it does NOT need the source codes. Input an Android apk, then we can get a 'ResGuard' apk in a few seconds.

Some uses of AndResGuard are:

1. Obfuscate android resources. It contains all the resource type(such as drawable、layout、string...). It can prevent your apk from being reversed by Apktool.

2. Shrinking the apk size. It can reduce the resources.arsc and the package size obviously.

3. Repackage with 7zip. It supports repackage apk with 7zip, and we can specify the compression method for each file.

AndResGuard is a command-line tool, it supports Windows, Linux and Mac. We suggest you to use 7zip in Linux or Mac platform for a higher compression ratio.

Note: Signature schemeV2 will make 7zip compressing invalid. If you really care about your APK size, please disable v2Signing in your signingConfigs

How to use

With Gradle

This has been released on Bintray

apply plugin: 'AndResGuard'

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.tencent.mm:AndResGuard-gradle-plugin:1.2.9'
    }
}

andResGuard {
    // mappingFile = file("./resource_mapping.txt")
    mappingFile = null
    // It will be invalid when you sign apk with schemeV2
    use7zip = true
    useSign = true
    // it will keep the origin path of your resources when it's true
    keepRoot = false

    whiteList = [
        // your icon
        "R.drawable.icon",
        // for fabric
        "R.string.com.crashlytics.*",
        // for google-services
        "R.string.google_app_id",
        "R.string.gcm_defaultSenderId",
        "R.string.default_web_client_id",
        "R.string.ga_trackingId",
        "R.string.firebase_database_url",
        "R.string.google_api_key",
        "R.string.google_crash_reporting_api_key"
    ]
    compressFilePattern = [
        "*.png",
        "*.jpg",
        "*.jpeg",
        "*.gif",
        "resources.arsc"
    ]
    sevenzip {
        artifact = 'com.tencent.mm:SevenZip:1.2.9'
        //path = "/usr/local/bin/7za"
    }

    /**
    * Optional: if finalApkBackupPath is null, AndResGuard will overwrite final apk
    * to the path which assemble[Task] write to
    **/
    // finalApkBackupPath = "${project.rootDir}/final.apk"

    /**
    * Optional: Specifies the name of the message digest algorithm to user when digesting the entries of JAR file
    * Only works in V1signing, default value is "SHA-1"
    **/
    // digestalg = "SHA-256"
}

The whiteList and compressFilePattern support wildcard include ? * +.

?	Zero or one character
*	Zero or more of character
+	One or more of character

If you are using Android Studio, you can find the generate task option in andresguard group. Or alternatively, you run ./gradlew resguard[BuildType | Flavor] in your terminal. The format of task name is as same as assemble.

The sevenzip can be set by path or artifact. Mutiple assignments are allowed, but the winner is always path.

The outputted apk will be stored in {App}/build/output/apk/AndResGuard_{apk_name}/{apk_name}_signed_7zip_aligned.apk.

You can find more whitsList configs of third-part SDK in white_list.md. Welcome PR your configs which is not included in white_list.md

The whiteList only works on the specsName of resources, it wouldn't keep the path of resource. If you wanna keeping the path, please use mappingFile to implement it.

For example, we wanna keeping the path of icon, we need add below into our mappingFile.

res path mapping:
    res/mipmap-hdpi-v4 -> res/mipmap-hdpi-v4
    res/mipmap-mdpi-v4 -> res/mipmap-mdpi-v4
    res/mipmap-xhdpi-v4 -> res/mipmap-xhdpi-v4
    res/mipmap-xxhdpi-v4 -> res/mipmap-xxhdpi-v4
    res/mipmap-xxxhdpi-v4 -> res/mipmap-xxxhdpi-v4

Looking for more detail

Known Issue

1. The first element of list which returned by AssetManager#list(String path) is empty string when you're using the APK which is compressed by 7zip. #162

Thanks

Apktool Connor Tumbleson

v2sig @jonyChina162