Android去掉/混淆Log,反編譯都看不到
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來源丨proguard官方
https://www.guardsquare.com/en/proguard/manual/examples#logging
出發點:
當然是由於編程習慣太好,打了一堆中文log,其實只是想給測試看。然而如果包被反編譯,看log基本都能理解流程了,有點尷尬。所以此文主要探究proguard配置,以去除log。
以下過程示例,來自於這段代碼。
public class MainActivity extends AppCompatActivity
{
private
static
final
String TAG ="MainActivity"
;private
String a ="a"
;private
String b ="b"
;@Override
protected
void
onCreate
(Bundle savedInstanceState)
{super
.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Log.d(TAG,"This is"
+ a + b); }}啥都不配置的情況下,反編譯的smali代碼如下:
# virtual methods method public
onCreate
(Landroid/os/Bundle;
)V .locals 2 invoke-super {p0, p1}, Landroid/support/v7/app/c;->onCreate(Landroid/os/Bundle;)Vconst
p1,0x7f09001b
invoke-virtual
{p0, p1}, Lcom/rentee/logremove/MainActivity;->setContentView(I)Vconst
-string
p1,"MainActivity"
new
-instance v0, Ljava/lang/StringBuilder;
const
-string
v1,"This is"
invoke-direct {v0, v1}, Ljava/lang/StringBuilder;->(Ljava/lang/String;)V iget-object
v1, p0, Lcom/rentee/logremove/MainActivity;->m:Ljava/lang/String; invoke-virtual
{v0, v1}, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder; iget-object
v1, p0, Lcom/rentee/logremove/MainActivity;->n:Ljava/lang/String; invoke-virtual
{v0, v1}, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder; invoke-virtual
{v0}, Ljava/lang/StringBuilder;->toString()Ljava/lang/String; move-result-object
v0 invoke-static
{p1, v0}, Landroid/util/Log;->d(Ljava/lang/String;Ljava/lang/String;)I
return
-void
.end method很明顯,整條字元串拼接過程是由StringBuilder完成的。
1.在build.gradle配置proguard-android-optimize.txt,因為默認的proguard-android.txt優化開關是關了的,而proguard的assumenosideeffects、assumenoexternalsideeffects配置是需要開啟優化開關的。
buildTypes release minifyEnabled true "proguard-android-optimize.txt" "proguard-rules.pro"
} }
在proguard-rules.pro文件中配置assumenosideeffects。這是網上的通用大解。
class android util Log-assumenosideeffects
public
static
boolean
isLoggable
(java.lang.String,
int
);public
static
int
v
(...)
;public
static
int
i
(...)
;public
static
int
w
(...)
;public
static
int
d
(...)
;public
static
int
e
(...)
;}不過也的確存在一個問題,就是去除不幹凈,反編譯後,smail如下:
# virtual methods method public onCreate Landroid/os/Bundle;
const
p1,0x7f09001b
invoke-virtual
{p0, p1}, Lcom/rentee/logremove/MainActivity;->setContentView(I)Vnew
-instance p1, Ljava/lang/StringBuilder;const
-string
v0,"This is"
invoke-direct {p1, v0}, Ljava/lang/StringBuilder;->(Ljava/lang/String;)V iget-object
v0, p0, Lcom/rentee/logremove/MainActivity;->m:Ljava/lang/String; invoke-virtual
{p1, v0}, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder; iget-object
v0, p0, Lcom/rentee/logremove/MainActivity;->n:Ljava/lang/String; invoke-virtual
{p1, v0}, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder;return
-void
.end methodLog的相關代碼沒了,但是還是有StringBuilder的拼接過程在,這個從根本上解決不了問題。
2.進化版,proguard 6.0以上版本新增了assumenoexternalsideeffects和assumenoexternalreturnvalues,這兩個屬性6.0才引入,Android自帶proguard-gradle插件並沒有這麼新,所以要在工程項目根目錄配置如下strategy,強制將progurad指定到6.0以上版本。
"net.sf.proguard:proguard-gradle:6.0.3"buildscript { configurations.all { resolutionStrategy { force
然後在progaurd-rules.txt文件中增加如下配置:
class java lang StringBuilder-assumenoexternalsideeffects
public
java.lang.StringBuilder();public
java.lang.StringBuilder(int
);public
java.lang.StringBuilder(java.lang.String);public
java.lang.StringBuilder
append
(java.lang.Object)
;public
java.lang.StringBuilder
append
(java.lang.String)
;public
java.lang.StringBuilder
append
(java.lang.StringBuffer)
;public
java.lang.StringBuilder
append
(
char
[]);public
java.lang.StringBuilder
append
(
char
[],int
,int
);public
java.lang.StringBuilder
append
(
boolean
);public
java.lang.StringBuilder
append
(
char
);public
java.lang.StringBuilder
append
(
int
);public
java.lang.StringBuilder
append
(
long
);public
java.lang.StringBuilder
append
(
float
);public
java.lang.StringBuilder
append
(
double
);public
java.lang.String
toString
()
;}-assumenoexternalreturnvaluespublic
final
class
java
.lang
.StringBuilder
{public
java.lang.StringBuilder
append
(java.lang.Object)
;public
java.lang.StringBuilder
append
(java.lang.String)
;public
java.lang.StringBuilder
append
(java.lang.StringBuffer)
;public
java.lang.StringBuilder
append
(
char
[]);public
java.lang.StringBuilder
append
(
char
[],int
,int
);public
java.lang.StringBuilder
append
(
boolean
);public
java.lang.StringBuilder
append
(
char
);public
java.lang.StringBuilder
append
(
int
);public
java.lang.StringBuilder
append
(
long
);public
java.lang.StringBuilder
append
(
float
);public
java.lang.StringBuilder
append
(
double
);}這段配置的作用是,去除返回值無用的StringBuilder的相關操作,由於在第2點配置後,Log相關代碼被去除,所以Log中的字元串拼接也是無用的,會被去除。配置後smali代碼是:
# virtual methods method public onCreate Landroid/os/Bundle;
const
p1,0x7f09001b
invoke-virtual
{p0, p1}, Lcom/rentee/logremove/MainActivity;->setContentView(I)Vreturn
-void
.end method是的,一句都沒有了,乾乾淨淨,爽!
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