Android WebView违规获取MAC地址解决方案

左手的ㄟ右手 2022-10-06 05:49 512阅读 0赞

#### 一、需求背景 ####

最近app的合规检查特别的严格，app在同意隐私协议之前不允许获取用户的隐私信息，但是很多的隐私合规都是写在H5中的，通过webview打开h5会获取mac地址，所有要想通过合规检查就必须让webview打开h5的时候获取不到mac地址。

#### 二、解决方案 ####

##### 1.方案思路 #####

经过多种的尝试最后想到了解决方案，既然是去获取了MAC地址，必定要调用系统的API，那么只要去HOOK系统的方法在获取mac地址的时候返回空字符串就可以了。

##### 2.代码实现 #####

object HookMacAddressUtils { 
        /** * 缓存wifi信息 */
        private var cacheWifiInfo: WifiInfo? = null
    
        /** * 是否hook mac地址标示 */
        private var isHookMacAddress = true
    
        /** * hook mac地址为空字符串 * @param context 上下文 */
        @SuppressLint("PrivateApi", "WifiManagerPotentialLeak")
        fun hookMacAddress(context: Context) { 
            try { 
                isHookMacAddress = true
                val iWifiManager = Class.forName("android.net.wifi.IWifiManager")
                val serviceField = WifiManager::class.java.getDeclaredField("mService")
                serviceField.isAccessible = true
                val wifi = context.getSystemService(Context.WIFI_SERVICE) as WifiManager
                val realIwm = serviceField[wifi]
                //hook getConnectionInfo的mac地址为空字符串
                serviceField[wifi] = Proxy.newProxyInstance(iWifiManager.classLoader, arrayOf(iWifiManager), MacAddressInvocationHandler("getConnectionInfo", realIwm))
            } catch (e: Exception) { 
                e.printStackTrace()
            }
        }
    
        /** * 关闭hook mac地址 */
        fun closeHookMacAddress() { 
            isHookMacAddress = false
        }
    
    
        class MacAddressInvocationHandler(private val methodName: String, private val real: Any?) : InvocationHandler { 
    
            override fun invoke(proxy: Any, method: Method, args: Array<Any>): Any { 
                return if (isHookMacAddress && methodName == method.name) { 
                    cacheWifiInfo?.let { 
                        return it
                    }
                    var wifiInfo: WifiInfo? = null
                    try { 
                        val cls: Class<*> = WifiInfo::class.java
                        wifiInfo = cls.newInstance() as WifiInfo
                        val mMacAddressField = cls.getDeclaredField("mMacAddress")
                        mMacAddressField.isAccessible = true
                        mMacAddressField[wifiInfo] = ""
                        cacheWifiInfo = wifiInfo
                    } catch (e: Exception) { 
                        e.printStackTrace()
                    }
                    wifiInfo!!
                } else { 
                    method.invoke(real, *args)
                }
            }
        }
    }

##### 3.调用方式 #####

在隐私弹框显示的时候调用hookMacAddress()

IHHookMacAddressUtils.hookMacAddress(activity.getApplicationContext())
    IHHookMacAddressUtils.hookMacAddress(activity)

在同意隐私协议之后关闭hook

IHHookMacAddressUtils.closeHookMacAddress()