使用 proguard 的 Android 混淆应用程序会不断混淆库 jar - 或者是这样？

Question

我是使用 Proguard 的新手，所以我可能犯了一个新手错误。我有一个应用程序，在运行发布版本（使用 Proguard 进行混淆）后，它很快就会崩溃。我相信我已经将范围缩小到了这样一个事实：它似乎混淆了我的参考库。就我而言，我的参考库用于定义我用来使用 Google Protobuffers 与另一个设备进行通信的消息类。我正在使用 ant release 进行构建。 我的 proguard 配置是：

-optimizationpasses 5
-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-dontpreverify
-verbose
-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*

-keep public class * extends android.app.Activity
-keep public class * extends android.app.Application
-keep public class * extends android.app.Service
-keep public class * extends android.content.BroadcastReceiver
-keep public class * extends android.content.ContentProvider
-keep public class * extends android.app.backup.BackupAgentHelper
-keep public class * extends android.preference.Preference
-keep public class com.android.vending.licensing.ILicensingService

-keepclasseswithmembernames class * 
 {
    native <methods>;
 }

-keepclasseswithmembernames class * 
 {
    public <init>(android.content.Context, android.util.AttributeSet);
 }

-keepclasseswithmembernames class * 
 {
    public <init>(android.content.Context, android.util.AttributeSet, int);
 }

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

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

在我的 ant build.xml 文件中，我定义了以下内容：

<target name="-obfuscate" unless="do.not.compile">
    <if condition="${proguard.enabled}">
        <then>
            <property name="obfuscate.absolute.dir" location="${out.absolute.dir}/proguard" />
            <property name="preobfuscate.jar.file"  value="${obfuscate.absolute.dir}/original.jar" />
            <property name="obfuscated.jar.file"    value="${obfuscate.absolute.dir}/obfuscated.jar" />

             <!-- input for dex will be proguard's output -->
            <property name="out.dex.input.absolute.dir" value="${obfuscated.jar.file}" />

            <!-- Add Proguard Tasks -->
            <property name="proguard.jar" location="${android.tools.dir}/proguard/lib/proguard.jar" />
            <taskdef name="proguard" classname="proguard.ant.ProGuardTask" classpath="${proguard.jar}" />

            <!-- Set the android classpath Path object into a single property. It'll be
                 all the jar files separated by a platform path-separator.
            -->
            <property name="android.libraryjars" refid="android.target.classpath"/>

            <!-- Build a path object with all the jar files that must be obfuscated.
                 This include the project compiled source code and any 3rd party jar
                 files. 
            -->
            <path id="project.jars.ref">
                <pathelement location="${preobfuscate.jar.file}" />
                <path refid="jar.libs.ref" />
            </path>

            <!-- Set the project jar files Path object into a single property. It'll be
                 all the jar files separated by a platform path-separator.
            -->
            <property name="project.jars" refid="project.jars.ref" />

            <mkdir  dir="${obfuscate.absolute.dir}" />
            <delete file="${preobfuscate.jar.file}" />
            <delete file="${obfuscated.jar.file}"   />
            <jar basedir="${out.classes.dir}" destfile="${preobfuscate.jar.file}" />
            <proguard>
                @${proguard.config}
                -injars ${project.jars}
                -outjars ${obfuscated.jar.file}
                -libraryjars ${android.libraryjars}
                -dump ${obfuscate.absolute.dir}/dump.txt
                -printseeds ${obfuscate.absolute.dir}/seeds.txt
                -printusage ${obfuscate.absolute.dir}/usage.txt
                -printmapping ${obfuscate.absolute.dir}/mapping.txt
            </proguard>
        </then>
    </if>
</target>

<!-- Converts this project's .class files into .dex files -->
<target name="-dex" depends="compile, -post-compile, -obfuscate"
        unless="do.not.compile">
    <if condition="${manifest.hasCode}">
        <then>
            <dex-helper />
        </then>
        <else>
            <echo>hasCode = false. Skipping...</echo>
        </else>
    </if>
</target>

<!-- Puts the project's resources into the output package file
     This actually can create multiple resource package in case
     Some custom apk with specific configuration have been
     declared in default.properties.
     -->
<target name="-package-resources">
    <echo>Packaging resources</echo>
    <aapt executable="${aapt}"
            command="package"
            versioncode="${version.code}"
            debug="${build.packaging.debug}"
            manifest="AndroidManifest.xml"
            assets="${asset.absolute.dir}"
            androidjar="${android.jar}"
            apkfolder="${out.absolute.dir}"
            resourcefilename="${resource.package.file.name}"
            resourcefilter="${aapt.resource.filter}">
        <res path="${resource.absolute.dir}" />
        <!-- <nocompress /> forces no compression on any files in assets or res/raw -->
        <!-- <nocompress extension="xml" /> forces no compression on specific file extensions in assets and res/raw -->
    </aapt>
</target>

<!-- Packages the application and sign it with a debug key. -->
<target name="-package-debug-sign" depends="-dex, -package-resources">
    <package-helper
            output.filepath="${out.debug.unaligned.file}" />
</target>

<!-- Packages the application without signing it. -->
<target name="-package-release" depends="-dex, -package-resources">
    <package-helper
            output.filepath="${out.unsigned.file}"/>
</target>
    <target name="-set-release-mode">
        <!-- release mode is only valid if the manifest does not explicitly
             set debuggable to true. default is false.
             We actually store build.packaging.debug, not build.release -->
        <xpath input="AndroidManifest.xml" expression="/manifest/application/@android:debuggable"
               output="build.packaging.debug" default="false"/>

        <!-- Enable proguard -->
        <property name="proguard.enabled" value="true"/>
        <property name="proguard.config" value="proguard.cfg"/>

        <!-- signing mode: release -->
        <property name="build.signing.debug" value="false" />

        <if condition="${build.packaging.debug}">
            <then>
                <echo>*************************************************</echo>
                <echo>****  Android Manifest has debuggable=true   ****</echo>
                <echo>**** Doing DEBUG packaging with RELEASE keys ****</echo>
                <echo>*************************************************</echo>
            </then>
            <else>
                <!-- property only set in release mode.
                     Useful for if/unless attributes in target node
                     when using Ant before 1.8 -->
                <property name="build.mode.release" value="true"/>
            </else>
        </if>
    </target>

    <target name="release"
            depends="-set-release-mode, -release-obfuscation-check, -package-release, -release-prompt-for-password, -release-nosign"
                if="has.keystore"
                description="Builds the application. The generated apk file must be signed before
                            it is published.">
        <!-- Signs the APK -->
        <echo>Signing final apk...</echo>
        <signjar
                jar="${out.unsigned.file}"
                signedjar="${out.unaligned.file}"
                keystore="${key.store}"
                storepass="${key.store.password}"
                alias="${key.alias}"
                keypass="${key.alias.password}"
                verbose="${verbose}" />

        <!-- Zip aligns the APK -->
        <zipalign-helper in.package="${out.unaligned.file}"
                                   out.package="${out.release.file}" />
        <echo>Release Package: ${out.release.file}</echo>
    </target>

如果有任何想法，我将不胜感激。我从在线模板中复制了大部分构建和 proguard 配置，我怀疑我实际上是在指示 Proguard 混淆库 jar，或者我配置了一些东西。 在构建结束时，我在 cmd 窗口中看到以下输出：

[proguard] Writing output...
[proguard] Preparing output jar [C:\Workspace\UI\MyApp\build\proguard\obfuscated.jar]
[proguard]   Copying resources from program jar [C:\Workspace\UI\MyApp\build\proguard\original.jar]
[proguard]   Copying resources from program jar [C:\Workspace\UI\MyApp\libs\libmessaging.jar]
[proguard] Warning: can't write resource [META-INF/MANIFEST.MF] (Duplicate zip entry [libmessaging.jar:META-INF/MANIFEST.MF])
[proguard]   Copying resources from program jar [C:\Workspace\UI\MyApp\libs\protobuf-2.3.0.jar]
[proguard] Warning: can't write resource [META-INF/MANIFEST.MF] (Duplicate zip entry [protobuf-2.3.0.jar:META-INF/MANIFEST.MF])
[proguard] Printing classes to [C:\Workspace\Riptide1_1_ptr_74\WPG_HAWKSBILL\UI\MyApp\build\proguard\dump.txt]...

谢谢！

Answer 1

您已在 Proguard 配置中注释了您的库 jar 指令。
将：更改

# -libraryjars /libs/protobuf-2.3.0.jar
# -libraryjars /libs/libmessaging.jar

为：（

-libraryjars /libs/protobuf-2.3.0.jar
-libraryjars /libs/libmessaging.jar

然后不必在 build.xml 中定义库 jar）

编辑：
我发现另一种让 Proguard 单独保留库 jar 的方法是要求它保留它们的包名称，例如：

-keep class javax.** { *; }
-keep class org.** { *; }
-keep class twitter4j.** { *; }

Answer 2

当 proGuard 加密 jsoup 库时，我遇到了类似的问题。我通过将以下内容添加到我的 proguard-rules.txt 中来修复此问题：

-keep class org.jsoup** {
    *;
}

因此 build.gradle 最终将包含以下部分：

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