由于android本身機(jī)制船惨,系統(tǒng)應(yīng)用禁止使用webview功能,webview容易使JS注入漏洞味滞,從而輕易獲取到app的系統(tǒng)權(quán)限。
解決辦法:
1钮呀、驗(yàn)證webview的url,必須是配置過(guò)的host才允許訪問(wèn)爽醋。
2、繞過(guò)系統(tǒng)檢測(cè)蚂四,通過(guò)提前實(shí)例化安檢provider
/**
* 解決系統(tǒng)應(yīng)用不能訪問(wèn)webview的方法光戈,先hook拿到系統(tǒng)sProviderInstance實(shí)例
*/
public void hookWebView(){
int sdkInt = Build.VERSION.SDK_INT;
try {
Class<?> factoryClass = Class.forName("android.webkit.WebViewFactory");
Field field = factoryClass.getDeclaredField("sProviderInstance");
field.setAccessible(true);
Object sProviderInstance = field.get(null);
if (sProviderInstance != null) {
Log.i(TAG,"sProviderInstance isn't null");
return;
}
Method getProviderClassMethod;
if (sdkInt > 22) {
getProviderClassMethod = factoryClass.getDeclaredMethod("getProviderClass");
} else if (sdkInt == 22) {
getProviderClassMethod = factoryClass.getDeclaredMethod("getFactoryClass");
} else {
Log.i(TAG,"Don't need to Hook WebView");
return;
}
getProviderClassMethod.setAccessible(true);
Class<?> factoryProviderClass = (Class<?>) getProviderClassMethod.invoke(factoryClass);
Class<?> delegateClass = Class.forName("android.webkit.WebViewDelegate");
Constructor<?> delegateConstructor = delegateClass.getDeclaredConstructor();
delegateConstructor.setAccessible(true);
if(sdkInt < 26){//低于Android O版本
Constructor<?> providerConstructor = factoryProviderClass.getConstructor(delegateClass);
if (providerConstructor != null) {
providerConstructor.setAccessible(true);
sProviderInstance = providerConstructor.newInstance(delegateConstructor.newInstance());
}
} else {
Field chromiumMethodName = factoryClass.getDeclaredField("CHROMIUM_WEBVIEW_FACTORY_METHOD");
chromiumMethodName.setAccessible(true);
String chromiumMethodNameStr = (String)chromiumMethodName.get(null);
if (chromiumMethodNameStr == null) {
chromiumMethodNameStr = "create";
}
Method staticFactory = factoryProviderClass.getMethod(chromiumMethodNameStr, delegateClass);
if (staticFactory!=null){
sProviderInstance = staticFactory.invoke(null, delegateConstructor.newInstance());
}
}
if (sProviderInstance != null){
field.set("sProviderInstance", sProviderInstance);
Log.i(TAG,"Hook success!");
} else {
Log.i(TAG,"Hook failed!");
}
} catch (Throwable e) {
Log.w(TAG,e);
}
}