Android逆向之路---Faceu的登录功能真的只提交了用户名和密码吗

问题

几乎99%的软件都有登录功能，而登录这一个动作真的将我们的用户名和密码上传到了服务器吗，会不会有个人隐私呢。根据我们这个问题，我们用FaceU这个软件，逆向来看看他的登录功能到底都传了什么数据。

准备工作

首先下载faceu的APK，具体下载地址大家可以去各大应用市场，我下载的版本是v2.2.6。

需要的工具

apktool (拆包APK用)
dex2jar (反编译dex文件用)

需要的工具下载地址：github.com/hanhan12312…

拆包

首先，我们利用apktool拆包apk，执行命令

apktool d faceu.apk
复制代码

这样在当前文件夹就得到了一个faceu的文件夹。

定位代码

我们打开Faceu软件，点击下面的已有账号在此登录，然后弹出来登录界面，如图所示

我们利用字符串搜索法，这个页面的注册的EditText的hint字为"Faceu号/手机号"，我们搜索res文件夹内所有文件的内容，搜索此关键字找到两处，位置都在res/values/strings.xml文件内

strings.xml

<string name="str_account_hint">Faceu号 / 手机号</string>
<string name="str_search_user">Faceu号/手机号</string>复制代码

根据name我们也能知道，account_hint是账号的输入框，而另一个是用于搜索的。我们知道一个布局文件肯定有用到过这个值。所以我们在工程内搜索"str_account_hint"，可是结果却发现只有两处引用到，如图

看来faceu的程序员们是没有在布局中引用，那就有可能在java代码内引用到，那就去看看"str_account_hint"在代码对应的值是多少。
紧接着我们顺着str_account_hint这个名字在res/values/public.xml文件内搜索"str_account_hint"，public.xml是在编译期间生成的文字对应编译后资源的id。
public.xml

<public type="string" name="str_account_hint" id="0x7f070047" />
复制代码

由此我们可以看出在java代码内对应的是0x7f070047。因此我们再次在代码里面搜索0x7f070047试试。找到了引用到这个常量的地方。

在文件com/lemon/faceu/login/b内

    const v2, 0x7f070047 invoke-virtual {v1, v2}, Landroid/content/res/Resources;->getString(I)Ljava/lang/String; move-result-object v1 invoke-virtual {v0, v1}, Lcom/lemon/faceu/uimodule/view/AccountEditText->setHintText(Ljava/lang/String;)V复制代码

熟悉smali语法的话，我们能够读懂，这个翻译成Java代码其实就是

    String v1 = context.getString(0x7f070047);editText.setHintText(v1);
复制代码

目的是找到到这个字符串。

到此为止我们分析一下当前的类是个什么类，是个Activity?Fragment?还是自定义View。

我们找到当前页面网上翻几行，看看还有没有用到什么别的资源id,找到了如下代码

 const v0, 0x7f0e026e invoke-virtual {p1, v0}, Landroid/view/View;->findViewById(I)Landroid/view/View; move-result-object v0 check-cast v0, Lcom/lemon/faceu/uimodule/view/PasswordEditText; iput-object v0, p0, Lcom/lemon/faceu/login/b;->bpP:Lcom/lemon/faceu/uimodule/view/PasswordEditText;复制代码

很明显，这个凭借PasswordEditText名称我们也能发现他就是密码输入的EditText
翻译成java代码

    PasswordEditText v0 = (PasswordEditText)this.findViewById(0x7f0e026e);this.bpP = v0;
复制代码

根据这一句话我们在public.xml里面找到对应的xml

<public type="id" name="cet_login_password" id="0x7f0e026e" />
复制代码

然后我们再看看有没有布局文件引用到了cet_login_password，于是找到了4处

我们进入fragment_login.xml发现他只有登录页面的上半部分。却没有下面的取消和确认按钮。可以猜测他并不是Activity,Fragment，因为没有标志性的onCreate方法，父类最终也没有找到Activity，Fragment等。很可能是一个负责处理业务的类。

但是我们知道了当前的成员变量bpP就是对应的密码的EditText了，那么看看都哪里调用这个bpP了。
通过对当前类分析，我最终找到了Lu方法里面对应到了登录按钮的。

逆向登录代码，查看传递参数

经过一番努力总算找到了登录界面，登录代码，现在我们进行分析，并且加入一段我们自己的代码，进行二次打包。
下面是分析详解

Lcom/lemon/faceu/login/b;

  .method Lu()V
    .locals 4    .prologue
    .line 216 invoke-virtual {p0}, Lcom/lemon/faceu/login/b;->Ls()Z#检测用户名是否合法 move-result v0#如果不合法就返回 if-eqz v0, :cond_0 invoke-virtual {p0}, Lcom/lemon/faceu/login/b;->Lt()Z#检测密码是否合法 move-result v0#如果不合法就返回 if-nez v0, :cond_1    .line 241 :cond_0 :goto_0 return-void

    .line 220 :cond_1 invoke-virtual {p0}, Lcom/lemon/faceu/login/b;->Uv()V    .line 222 const-string v0, "LoginFragment" const-string v1, "startLogin" invoke-static {v0, v1}, Lcom/lemon/faceu/sdk/utils/c;->i(Ljava/lang/String;Ljava/lang/String;)V#调用Faceu自己的统计打点方法    .line 223 iget-object v0, p0, Lcom/lemon/faceu/login/b;->bpO:Lcom/lemon/faceu/uimodule/view/AccountEditText; invoke-virtual {v0}, Lcom/lemon/faceu/uimodule/view/AccountEditText;->getAccount()Ljava/lang/String; move-result-object v0#调用AccountEditText的getAccount方法，并将用户户名存入v0  iput-object v0, p0, Lcom/lemon/faceu/login/b;->aAS:Ljava/lang/String;#将aAs赋值为用户名    .line 224 iget-object v0, p0, Lcom/lemon/faceu/login/b;->bpP:Lcom/lemon/faceu/uimodule/view/PasswordEditText; invoke-virtual {v0}, Lcom/lemon/faceu/uimodule/view/PasswordEditText;->getEditText()Landroid/widget/EditText; move-result-object v0 invoke-virtual {v0}, Landroid/widget/EditText;->getText()Landroid/text/Editable; move-result-object v0 invoke-virtual {v0}, Ljava/lang/Object;->toString()Ljava/lang/String; move-result-object v0#将密码从bpP取出来，并取出String类型的密码复制给v0    .line 227 invoke-static {}, Lcom/lemon/faceu/common/e/a;->xJ()Lcom/lemon/faceu/common/e/a; move-result-object v1 iget-object v2, p0, Lcom/lemon/faceu/login/b;->aAS:Ljava/lang/String; invoke-virtual {v1, v2}, Lcom/lemon/faceu/common/e/a;->setAccount(Ljava/lang/String;)V#将现在的用户名存入sharedprefence，以便于记住用户名下次直接显示    .line 229 new-instance v1, Ljava/util/HashMap;#new一个HashMap存储进v1 invoke-direct {v1}, Ljava/util/HashMap;-><init>()V#初始化v1    .line 230 const-string v2, "account" iget-object v3, p0, Lcom/lemon/faceu/login/b;->aAS:Ljava/lang/String; invoke-interface {v1, v2, v3}, Ljava/util/Map;->put(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;#将用户名存入HashMap    .line 231 const-string v2, "pwd" invoke-static {v0}, Lcom/lemon/faceu/common/i/g;->bS(Ljava/lang/String;)Ljava/lang/String; move-result-object v0 invoke-interface {v1, v2, v0}, Ljava/util/Map;->put(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;#将密码调用bS方法加密并且存入map    .line 232 const-string v0, "councode" const-string v2, "86" invoke-interface {v1, v0, v2}, Ljava/util/Map;->put(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;#国家编号86，存入map    .line 233 const-string v0, "manufacture" sget-object v2, Landroid/os/Build;->MANUFACTURER:Ljava/lang/String; invoke-interface {v1, v0, v2}, Ljava/util/Map;->put(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;#将厂商信息存入map    .line 234 const-string v0, "model" sget-object v2, Landroid/os/Build;->MODEL:Ljava/lang/String; invoke-interface {v1, v0, v2}, Ljava/util/Map;->put(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;#将model信息存入map    .line 235 const-string v0, "version" sget v2, Lcom/lemon/faceu/common/d/b;->aAL:I invoke-static {v2}, Ljava/lang/String;->valueOf(I)Ljava/lang/String; move-result-object v2 invoke-interface {v1, v0, v2}, Ljava/util/Map;->put(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;#将软件版本信息存入map    .line 236 const-string v0, "deviceinfo" invoke-static {}, Lcom/lemon/faceu/common/b/a;->xt()Lorg/json/JSONObject; move-result-object v2#将调用com.lemon.faceu.common.b.a->xt()方法，取回JsonObject并且赋值给v2 invoke-interface {v1, v0, v2}, Ljava/util/Map;->put(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;#将JSONObject存入map    .line 238 new-instance v0, Lcom/lemon/faceu/common/t/a; sget-object v2, Lcom/lemon/faceu/common/d/a;->azO:Ljava/lang/String; invoke-static {}, Landroid/os/Looper;->getMainLooper()Landroid/os/Looper; move-result-object v3 invoke-direct {v0, v2, v1, v3}, Lcom/lemon/faceu/common/t/a;-><init>(Ljava/lang/String;Ljava/util/Map;Landroid/os/Looper;)V    .line 239 iget-object v1, p0, Lcom/lemon/faceu/login/b;->aKe:Lcom/lemon/faceu/common/t/a$a; invoke-virtual {v0, v1}, Lcom/lemon/faceu/common/t/a;->a(Lcom/lemon/faceu/common/t/a$a;)V    .line 240 const-string v1, "login" invoke-static {v0, v1}, Lcom/lemon/faceu/sdk/i/b;->a(Ljava/lang/Runnable;Ljava/lang/String;)V goto :goto_0
.end method  #此方法主要校验用户名是否合法，错误的话输出错误信息，返回值为boolean
.method Ls()Z
    .locals 5    .prologue const/4 v1, 0x0 #使v0寄存器为0
    .line 177 iget-object v0, p0, Lcom/lemon/faceu/login/b;->bpO:Lcom/lemon/faceu/uimodule/view/AccountEditText;#将成员变量bpO赋值给v0，此时v0就是用户名 invoke-virtual {v0}, Lcom/lemon/faceu/uimodule/view/AccountEditText;->getAccount()Ljava/lang/String; move-result-object v2#调用AccountEditText的getAccount方法，并将返回值存入v2    .line 178 invoke-virtual {v2}, Ljava/lang/String;->length()I#取出用户名长度 move-result v0#v0 = 用户名长度 if-lez v0, :cond_0 invoke-virtual {v2, v1}, Ljava/lang/String;->charAt(I)C move-result v0 invoke-static {v0}, Ljava/lang/Character;->isDigit(C)Z move-result v0 if-eqz v0, :cond_0    .line 180 invoke-static {v2}, Lcom/lemon/faceu/common/u/t;->dz(Ljava/lang/String;)Z move-result v0 if-nez v0, :cond_4    .line 181 iget-object v0, p0, Lcom/lemon/faceu/login/b;->bpO:Lcom/lemon/faceu/uimodule/view/AccountEditText; const v2, 0x7f0700ae invoke-virtual {p0, v2}, Lcom/lemon/faceu/login/b;->getString(I)Ljava/lang/String; move-result-object v2 invoke-virtual {v0, v2}, Lcom/lemon/faceu/uimodule/view/AccountEditText;->setTips(Ljava/lang/String;)V    .line 202 :goto_0 return v1    .line 185 :cond_0 invoke-virtual {v2}, Ljava/lang/String;->length()I move-result v0 const/16 v3, 0x14 if-le v0, v3, :cond_1    .line 186 iget-object v0, p0, Lcom/lemon/faceu/login/b;->bpO:Lcom/lemon/faceu/uimodule/view/AccountEditText; const v2, 0x7f070087 invoke-virtual {p0, v2}, Lcom/lemon/faceu/login/b;->getString(I)Ljava/lang/String; move-result-object v2 invoke-virtual {v0, v2}, Lcom/lemon/faceu/uimodule/view/AccountEditText;->setTips(Ljava/lang/String;)V goto :goto_0    .line 188 :cond_1 invoke-virtual {v2}, Ljava/lang/String;->length()I move-result v0 if-lez v0, :cond_2 invoke-virtual {v2, v1}, Ljava/lang/String;->charAt(I)C move-result v0 invoke-static {v0}, Lcom/lemon/faceu/sdk/utils/h;->u(C)Z move-result v0 if-nez v0, :cond_2    .line 189 iget-object v0, p0, Lcom/lemon/faceu/login/b;->bpO:Lcom/lemon/faceu/uimodule/view/AccountEditText; const v2, 0x7f070086 invoke-virtual {p0, v2}, Lcom/lemon/faceu/login/b;->getString(I)Ljava/lang/String; move-result-object v2 invoke-virtual {v0, v2}, Lcom/lemon/faceu/uimodule/view/AccountEditText;->setTips(Ljava/lang/String;)V goto :goto_0 :cond_2 move v0, v1    .line 192 :goto_1 invoke-virtual {v2}, Ljava/lang/String;->length()I move-result v3 if-ge v0, v3, :cond_4    .line 193 invoke-virtual {v2, v0}, Ljava/lang/String;->charAt(I)C move-result v3    .line 194 const/16 v4, 0x5f if-eq v3, v4, :cond_3 invoke-static {v3}, Ljava/lang/Character;->isDigit(C)Z move-result v4 if-nez v4, :cond_3 invoke-static {v3}, Lcom/lemon/faceu/sdk/utils/h;->u(C)Z move-result v3 if-nez v3, :cond_3    .line 195 iget-object v0, p0, Lcom/lemon/faceu/login/b;->bpO:Lcom/lemon/faceu/uimodule/view/AccountEditText; const v2, 0x7f070085 invoke-virtual {p0, v2}, Lcom/lemon/faceu/login/b;->getString(I)Ljava/lang/String; move-result-object v2 invoke-virtual {v0, v2}, Lcom/lemon/faceu/uimodule/view/AccountEditText;->setTips(Ljava/lang/String;)V goto :goto_0    .line 192 :cond_3 add-int/lit8 v0, v0, 0x1 goto :goto_1    .line 202 :cond_4 const/4 v1, 0x1 goto :goto_0
.end method
#此方法主要校验密码是否合法，错误的话输出错误信息，做一些动画之类，正确返回true
.method Lt()Z
    .locals 2    .prologue
    .line 206 iget-object v0, p0, Lcom/lemon/faceu/login/b;->bpP:Lcom/lemon/faceu/uimodule/view/PasswordEditText; invoke-virtual {v0}, Lcom/lemon/faceu/uimodule/view/PasswordEditText;->getEditText()Landroid/widget/EditText; move-result-object v0 invoke-virtual {v0}, Landroid/widget/EditText;->getText()Landroid/text/Editable; move-result-object v0 invoke-virtual {v0}, Ljava/lang/Object;->toString()Ljava/lang/String; move-result-object v0 invoke-virtual {v0}, Ljava/lang/String;->length()I move-result v0    .line 207 const/4 v1, 0x6 if-lt v0, v1, :cond_0 const/16 v1, 0x10 if-le v0, v1, :cond_1    .line 208 :cond_0 iget-object v0, p0, Lcom/lemon/faceu/login/b;->bpP:Lcom/lemon/faceu/uimodule/view/PasswordEditText; const v1, 0x7f0700b5 invoke-virtual {p0, v1}, Lcom/lemon/faceu/login/b;->getString(I)Ljava/lang/String; move-result-object v1 invoke-virtual {v0, v1}, Lcom/lemon/faceu/uimodule/view/PasswordEditText;->setTips(Ljava/lang/String;)V    .line 209 const/4 v0, 0x0    .line 211 :goto_0 return v0 :cond_1 const/4 v0, 0x1 goto :goto_0
.end method复制代码

我们主要看Lu方法里面的以下几行，他调用了com.lemon.faceu.common.b.a->xt()方法，这个主要是用于窃取我们的手机型号，系统，厂商等信息，我们进入方法看看

    const-string v0, "deviceinfo" invoke-static {}, Lcom/lemon/faceu/common/b/a;->xt()Lorg/json/JSONObject; move-result-object v2#将调用com.lemon.faceu.common.b.a->xt()方法，取回JsonObject并且赋值给v2复制代码

我们进入方法看看


.method public static xt()Lorg/json/JSONObject;
    .locals 5    .prologue
    .line 34 new-instance v1, Lorg/json/JSONObject; invoke-direct {v1}, Lorg/json/JSONObject;-><init>()V    .line 36 :try_start_0 const-string v0, "cpu" invoke-static {}, Lcom/lemon/faceu/common/b/a;->xv()Ljava/lang/String; move-result-object v2 invoke-virtual {v1, v0, v2}, Lorg/json/JSONObject;->put(Ljava/lang/String;Ljava/lang/Object;)Lorg/json/JSONObject;#取出你的cpu信息放入json    .line 37 const-string v0, "radio" invoke-static {}, Lcom/lemon/faceu/common/b/a;->xx()Ljava/lang/String; move-result-object v2 invoke-virtual {v1, v0, v2}, Lorg/json/JSONObject;->put(Ljava/lang/String;Ljava/lang/Object;)Lorg/json/JSONObject;#机型的RADIO信息存入json    .line 38 const-string v0, "os_version" sget v2, Landroid/os/Build$VERSION;->SDK_INT:I invoke-virtual {v1, v0, v2}, Lorg/json/JSONObject;->put(Ljava/lang/String;I)Lorg/json/JSONObject;#取出你系统版本    .line 39 const-string v0, "imei" invoke-static {}, Lcom/lemon/faceu/common/e/a;->xJ()Lcom/lemon/faceu/common/e/a; move-result-object v2#取出IMEI号 invoke-virtual {v2}, Lcom/lemon/faceu/common/e/a;->getContext()Landroid/content/Context; move-result-object v2 invoke-static {v2}, Lcom/lemon/faceu/common/b/a;->bd(Landroid/content/Context;)Ljava/lang/String; move-result-object v2 invoke-virtual {v1, v0, v2}, Lorg/json/JSONObject;->put(Ljava/lang/String;Ljava/lang/Object;)Lorg/json/JSONObject;    .line 40 const-string v0, "imsi" invoke-static {}, Lcom/lemon/faceu/common/b/a;->xy()Ljava/lang/String; move-result-object v2 invoke-virtual {v1, v0, v2}, Lorg/json/JSONObject;->put(Ljava/lang/String;Ljava/lang/Object;)Lorg/json/JSONObject;    .line 41 const-string v0, "iccid" invoke-static {}, Lcom/lemon/faceu/common/b/a;->xz()Ljava/lang/String; move-result-object v2 invoke-virtual {v1, v0, v2}, Lorg/json/JSONObject;->put(Ljava/lang/String;Ljava/lang/Object;)Lorg/json/JSONObject;    .line 42 const-string v0, "android_id" invoke-static {}, Lcom/lemon/faceu/common/b/a;->xw()Ljava/lang/String; move-result-object v2 invoke-virtual {v1, v0, v2}, Lorg/json/JSONObject;->put(Ljava/lang/String;Ljava/lang/Object;)Lorg/json/JSONObject;    .line 43 const-string v0, "model" sget-object v2, Landroid/os/Build;->MODEL:Ljava/lang/String; invoke-virtual {v1, v0, v2}, Lorg/json/JSONObject;->put(Ljava/lang/String;Ljava/lang/Object;)Lorg/json/JSONObject;    .line 44 const-string v0, "core_count" invoke-static {}, Lcom/lemon/faceu/common/b/a;->xA()I move-result v2 invoke-virtual {v1, v0, v2}, Lorg/json/JSONObject;->put(Ljava/lang/String;I)Lorg/json/JSONObject;    .line 45 const-string v0, "wifi" invoke-static {}, Lcom/lemon/faceu/common/b/a;->xu()Ljava/lang/String; move-result-object v2 invoke-virtual {v1, v0, v2}, Lorg/json/JSONObject;->put(Ljava/lang/String;Ljava/lang/Object;)Lorg/json/JSONObject; :try_end_0
    .catch Lorg/json/JSONException; {:try_start_0 .. :try_end_0} :catch_0    .line 49 :goto_0 return-object v1    .line 46 :catch_0 move-exception v0    .line 47 const-string v2, "DeviceInfo" new-instance v3, Ljava/lang/StringBuilder; invoke-direct {v3}, Ljava/lang/StringBuilder;-><init>()V const-string v4, "jsonexception, " invoke-virtual {v3, v4}, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder; move-result-object v3 invoke-virtual {v0}, Lorg/json/JSONException;->getMessage()Ljava/lang/String; move-result-object v0 invoke-virtual {v3, v0}, Ljava/lang/StringBuilder;->append(Ljava/lang/String;)Ljava/lang/StringBuilder; move-result-object v0 invoke-virtual {v0}, Ljava/lang/StringBuilder;->toString()Ljava/lang/String; move-result-object v0 invoke-static {v2, v0}, Lcom/lemon/faceu/sdk/utils/c;->e(Ljava/lang/String;Ljava/lang/String;)V goto :goto_0
.end method复制代码

我们能看到他获取了我们的cpu，radio，os_version(系统版本),imei，MODEL,cpu_count,mac地址。看了半天代码，我们加入一些我们的代码，让程序自己把提交的信息打印出来吧。

 const-string v0, "MartinHan--map" invoke-virtual {v1}, Ljava/util/HashMap;->toString()Ljava/lang/String; move-result-object v3 invoke-static {v0, v3}, Landroid/util/Log;->v(Ljava/lang/String;Ljava/lang/String;)I const-string v3, "MartinHan---url" invoke-static {v3, v2}, Landroid/util/Log;->v(Ljava/lang/String;Ljava/lang/String;)I复制代码

然后我们执行代码

apktool d faceu
cd faceu/disk
#签名 生成文件明为_signed.apk
jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -keystore "MartinHan.jks" -signedjar "_signed.apk" "faceu.apk" "111111" << EOF
111111adb install _signed.apk复制代码

这样的流程走下来，我们的二次打包apk就安装到手机上啦，看看我们输入我们帐号，点击登录。会打印出log信息。
如下所示

03-13 14:17:15.269 10240-10240/com.lemon.faceu V/MartinHan--map: {account=159xxxxxxxx, deviceinfo={"android_id":"62fjdhu42d070400","wifi":"08:33:61:cc:b9:fc","model":"HUAWEI G630-U00","imei":"81338398767854654","iccid":"","cpu":"ARMv7 Processor rev 3 (v7l) ","radio":"203040,203040","imsi":"","core_count":4,"os_version":18}, model=HUAWEI G630-U00, pwd=4d259481d57ffc1c6b4b68cd73dbd301, councode=86, manufacture=HUAWEI, version=270540806}03-13 14:17:15.269 10240-10240/com.lemon.faceu V/MartinHan---url: https://api2.faceu.mobi/faceu/v3/login.php
复制代码

如上诉代码所示，我们在faceu登录一次，faceu会上传我们的很多个人信息
mac地址，手机型号，imei，cpu信息，radio，系统版本，国家代码，并且找到了faceu登录的地址是https://api2.faceu.mobi/faceu/v3/login.php

以上就是我的所有思路，从问题开始，一直找代码，最后动态的打log实现在https加密前就让app自己吐出数据。

写在最后

其实我想不仅faceu，像是其他的厂商也会收集我们的个人信息，完成统计。并且通过大数据分析使用软件的人群，手机型号。
希望所有喜欢逆向的朋友们一起探讨，多多交流。

注：如有侵权，请联系我

关于我

个人博客：MartinHan的小站

博客网站：hanhan12312的专栏

知乎：MartinHan01