Android混淆笔记

概述

module的build.gradle中有以下内容
buildTypes {
release {
minifyEnabled true
proguardFiles getDefaultProguardFile(‘proguard-android.txt’), ‘proguard-rules.pro’
}
}
其中：
- minifyEnabled表示是否在生成release版本时混淆代码
- getDefaultProguardFile(‘proguard-android.txt’) 方法可从 Android SDK tools/proguard/ 文件夹获取默认的 ProGuard 设置。
- proguard-rules.pro 文件用于添加自定义 ProGuard规则。默认情况下，该文件位于模块根目录（build.gradle 文件旁）
每次构建时 ProGuard 都会输出下列文件：
- dump.txt 说明 APK 中所有类文件的内部结构。
- mapping.txt 提供原始与混淆过的类、方法和字段名称之间的转换。
- seeds.txt 列出未进行混淆的类和成员。
- usage.txt 列出从 APK 移除的代码。
这些文件保存在 /build/outputs/mapping/release/ 中。

混淆配置相关

SDK中有一个默认的配置文件存放在android-sdk-windows\tools\proguard，内容如下：

# This is a configuration file for ProGuard.# http://proguard.sourceforge.net/index.html#manual/usage.html-dontusemixedcaseclassnames-dontskipnonpubliclibraryclasses-verbose# Optimization is turned off by default. Dex does not like code run# through the ProGuard optimize and preverify steps (and performs some# of these optimizations on its own).-dontoptimize-dontpreverify# Note that if you want to enable optimization, you cannot just# include optimization flags in your own project configuration file;# instead you will need to point to the# "proguard-android-optimize.txt" file instead of this one from your# project.properties file.-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*();}# 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>(...);}

一点点看上面内容
-dontusemixedcaseclassnames #是否使用大小写混合
-dontskipnonpubliclibraryclasses #非公开类也会被混淆
-verbose #打印混淆日志

-dontoptimize#关闭优化
-dontpreverify#混淆时是否做预校验

-keepattributes Annotation#指定混淆是采用的算法

-keep public class com.google.vending.licensing.ILicensingService-keep public class com.android.vending.licensing.ILicensingService

keep表示不混淆，上边就是不混淆上述两个类

-keepclasseswithmembernames class * {    native <methods>;}

保留所有的本地native方法不被混淆

-keepclassmembers public class * extends android.view.View {   void set*(***);   *** get*();}

不混淆所有继承android.view.View的类的set个get方法

-keepclassmembers class * extends android.app.Activity {   public void *(android.view.View);}

不混淆Activity里参数为View的方法，比如在layout中设置view的onclick就会出错

-keepclassmembers enum * {    public static **[] values();    public static ** valueOf(java.lang.String);}

不混淆enum类的values和valueOf方法

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

不混淆Parcelable的CREATOR字段

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

不混淆所有R文件静态字段，混淆会影响资源的id

-dontwarn android.support.**

忽略这个包下面的警告

# 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>(...);}

keep注解可以作用于包、类、接口、注解类型、构造器、方法、字段上，哪个地方加上@keep哪个地方就不会混淆。

  -dontwarn com.squareup.retrofit2.**  -keep class com.squareup.retrofit2.** { *;}

对于第三方依赖的库加上以上说明就可以了