android - 在 Android 上使用 RNCryptor

Question

我有一些使用 RNCryptor 加密的图像文件，我想解密它们并将它们用作 Framelayout 的背景。 我浏览了示例文件，但我的应用程序在一段时间后关闭并且没有显示任何图像。 我用 JNCryptor library

我将加密图像放入原始文件夹中，如下所示:

这是我的 Activity 中的代码:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    FrameLayout img = (FrameLayout) findViewById(R.id.scrollView);

    final String password = "myPasswordString";

    JNCryptor cryptor = new AES256JNCryptor();

    Resources res = getResources();
    InputStream in_s = res.openRawResource(R.raw.troodon_ph);
    byte[] b = null;
    byte[] data = null;
    try {
        b = new byte[in_s.available()];
        in_s.read(b);
    } catch (IOException e) {
        Log.i("decrypt error", e.toString());
    }

    try {
        data = cryptor.decryptData(b, password.toCharArray());
    } catch (InvalidHMACException e) {
        Log.i("decrypt error", e.toString());
    } catch (CryptorException e) {
        Log.i("decrypt error", e.toString());
    }

    Bitmap mBitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
    BitmapDrawable bDrawable = new BitmapDrawable(res, mBitmap);

    img.setBackgroundDrawable(bDrawable);
}

此文件在 iOS 上运行良好，代码如下:

NSString  *imagePath = [[NSBundle mainBundle] pathForResource:getName ofType:@"wod"];
NSData *encryptedData = [NSData dataWithContentsOfFile:imagePath];
NSData *decryptedData = [RNDecryptor decryptData:encryptedData
                                    withPassword:PASSWORD
                                           error:&error];

UIImage*  bgImage = [UIImage imageWithData:decryptedData];
UIImageView * movingImageView = [[UIImageView alloc]initWithImage:bgImage];

这是 logcat 输出:

08-28 19:52:11.720: E/AndroidRuntime(1063): FATAL EXCEPTION: main 08-28 19:52:11.720: E/AndroidRuntime(1063): java.lang.RuntimeException: Unable to start activity ComponentInfo{net.appersian.android.wod/net.appersian.android.wod.MainActivity}: java.lang.NullPointerException 08-28 19:52:11.720: E/AndroidRuntime(1063): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059) 08-28 19:52:11.720: E/AndroidRuntime(1063): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084) 08-28 19:52:11.720: E/AndroidRuntime(1063): at android.app.ActivityThread.access$600(ActivityThread.java:130) 08-28 19:52:11.720: E/AndroidRuntime(1063): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195) 08-28 19:52:11.720: E/AndroidRuntime(1063): at android.os.Handler.dispatchMessage(Handler.java:99) 08-28 19:52:11.720: E/AndroidRuntime(1063): at android.os.Looper.loop(Looper.java:137) 08-28 19:52:11.720: E/AndroidRuntime(1063): at android.app.ActivityThread.main(ActivityThread.java:4745) 08-28 19:52:11.720: E/AndroidRuntime(1063): at java.lang.reflect.Method.invokeNative(Native Method) 08-28 19:52:11.720: E/AndroidRuntime(1063): at java.lang.reflect.Method.invoke(Method.java:511) 08-28 19:52:11.720: E/AndroidRuntime(1063): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 08-28 19:52:11.720: E/AndroidRuntime(1063): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 08-28 19:52:11.720: E/AndroidRuntime(1063): at dalvik.system.NativeStart.main(Native Method) 08-28 19:52:11.720: E/AndroidRuntime(1063): Caused by: java.lang.NullPointerException 08-28 19:52:11.720: E/AndroidRuntime(1063): at net.appersian.android.wod.MainActivity.onCreate(MainActivity.java:54) 08-28 19:52:11.720: E/AndroidRuntime(1063): at android.app.Activity.performCreate(Activity.java:5008) 08-28 19:52:11.720: E/AndroidRuntime(1063): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079) 08-28 19:52:11.720: E/AndroidRuntime(1063): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023) 08-28 19:52:11.720: E/AndroidRuntime(1063): ... 11 more

解密文件时我做错了什么？

更新: 我将 e.printStackTrace() 添加到 try/catch，这是我的新 logcat:

08-28 20:54:10.496: W/System.err(1487): org.cryptonode.jncryptor.InvalidHMACException: Incorrect HMAC value. 08-28 20:54:10.496: W/System.err(1487): at org.cryptonode.jncryptor.AES256JNCryptor.decryptV3Data(AES256JNCryptor.java:244) 08-28 20:54:10.496: W/System.err(1487): at org.cryptonode.jncryptor.AES256JNCryptor.decryptV3Data(AES256JNCryptor.java:319) 08-28 20:54:10.496: W/System.err(1487): at org.cryptonode.jncryptor.AES256JNCryptor.decryptData(AES256JNCryptor.java:276) 08-28 20:54:10.496: W/System.err(1487): at net.appersian.android.wod.MainActivity.onCreate(MainActivity.java:50) 08-28 20:54:10.496: W/System.err(1487): at android.app.Activity.performCreate(Activity.java:5008) 08-28 20:54:10.496: W/System.err(1487): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079) 08-28 20:54:10.496: W/System.err(1487): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023) 08-28 20:54:10.496: W/System.err(1487): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084) 08-28 20:54:10.496: W/System.err(1487): at android.app.ActivityThread.access$600(ActivityThread.java:130) 08-28 20:54:10.496: W/System.err(1487): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195) 08-28 20:54:10.496: W/System.err(1487): at android.os.Handler.dispatchMessage(Handler.java:99) 08-28 20:54:10.496: W/System.err(1487): at android.os.Looper.loop(Looper.java:137) 08-28 20:54:10.496: W/System.err(1487): at android.app.ActivityThread.main(ActivityThread.java:4745) 08-28 20:54:10.496: W/System.err(1487): at java.lang.reflect.Method.invokeNative(Native Method) 08-28 20:54:10.496: W/System.err(1487): at java.lang.reflect.Method.invoke(Method.java:511) 08-28 20:54:10.496: W/System.err(1487): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 08-28 20:54:10.496: W/System.err(1487): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 08-28 20:54:10.496: W/System.err(1487): at dalvik.system.NativeStart.main(Native Method)

Answer 1

第一:

http://docs.oracle.com/javase/7/docs/api/java/io/InputStream.html#available%28%29

http://docs.oracle.com/javase/8/docs/technotes/guides/io/troubleshooting.html

请注意，虽然 InputStream 的某些实现将返回流中的字节总数，但许多实现不会返回。使用此方法的返回值来分配用于保存此流中所有数据的缓冲区是不正确的

我不确定这些会产生任何问题，但让我们尝试一下:

    InputStream is = getResources().openRawResource(R.raw.troodon_ph);
    BufferedInputStream bis = new BufferedInputStream(is);
    ByteArrayBuffer baf = new ByteArrayBuffer(50);
    int current = 0;
    try {
        while ((current = bis.read()) != -1) {

            baf.append((byte) current);

        }
    } catch (IOException e) {
        e.printStackTrace();
    }
    byte[] data = baf.toByteArray();

我希望它有效，但请告诉我!!

最后，如果它不起作用，请确保您的文件已正确加密。