python AES加密 java 解密

Question

我有超过 1000 个图像和视频需要加密。没有什么比这更简单的了，我正在考虑使用 AES，但我不知道如何在我的计算机上加密然后解密设备上的项目。

我将使用 python 来加密我计算机上的所有项目。然后以按需方式使用java（Android应用程序）解密该项目

任何简单的解释都会做伪代码也很好。

我遇到的主要问题是如何使用相同的密钥进行加密和解密。我一直在生成密钥，但无法将其移植到其他设备进行解密。

感谢

Python 代码。工作加密和解密。

from Crypto.Cipher import AES
import os, random, struct

key = '0123456789abcdef'
mode = AES.MODE_CBC
chunksize = 64*1024

iv = ''.join(chr(random.randint(0,0xFF)) for i in range(16))
encryptor = AES.new(key,mode,iv)
filesize = os.path.getsize('sample.jpg')

with open('sample.jpg','rb') as infile:
    with open('sample.enc','wb') as outfile:
       outfile.write(struct.pack('<Q',filesize))
       outfile.write(iv)

    while True:
        chunk = infile.read(chunksize)
        if len(chunk) == 0:
            break
        elif len(chunk) % 16 != 0:
            chunk += ' ' * (16 - len(chunk) % 16)

        outfile.write(encryptor.encrypt(chunk))

## decrypt
with open('sample.enc', 'rb') as infile:
       origsize = struct.unpack('<Q', infile.read(struct.calcsize('Q')))[0]
       iv = infile.read(16)
       decryptor = AES.new(key, AES.MODE_CBC, iv)

       with open('sample2.jpg', 'wb') as outfile:
          while True:
            chunk = infile.read(chunksize)
            if len(chunk) == 0:
                break
            outfile.write(decryptor.decrypt(chunk))

        outfile.truncate(origsize)

我将如何在Java中完成解密部分？这是我的快速草率的java代码，它不起作用。我认为是填充弄乱了它。

  public void decryptFile(){

    String inFile = "sample.enc";
    String outFile = "sample.jpg";
    String dir = Environment.getExternalStorageDirectory() +"/Android/data/HOT/";
    InputStream is ;
    byte[] iv = new byte[16];
    try {
        is = new FileInputStream(dir+inFile);

        is.read(iv);

    } catch (FileNotFoundException e1) {
        // TODO Auto-generated catch block
        Log.d("D1","no file found");
    } catch (IOException e) {
        // TODO Auto-generated catch block
        Log.d("D-2","no file found");
        e.printStackTrace();
    }

    byte[] k = {'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};

    Key key = new SecretKeySpec(k,"AES");




    try {
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, key,new IvParameterSpec(iv));
        OutputStream outs = new FileOutputStream(dir+outFile);
        is = new FileInputStream(dir+inFile);
        while(true){
            byte[] chunk = new byte[64*1024];
            is.read(chunk);
            if(chunk.length == 0){

                break;

            }
            outs.write(cipher.doFinal(chunk));              
        }


    } catch (NoSuchAlgorithmException e) {
        // TODO Auto-generated catch block
        Log.d("D","1");

        e.printStackTrace();
    } catch (NoSuchPaddingException e) {
        // TODO Auto-generated catch block
        Log.d("D","2");
        e.printStackTrace();
    } catch (InvalidKeyException e) {
        // TODO Auto-generated catch block
        Log.d("D","3");
        e.printStackTrace();
    } catch (InvalidAlgorithmParameterException e) {
        // TODO Auto-generated catch block
        Log.d("D","4");
        e.printStackTrace();
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        Log.d("D","5");
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        Log.d("D","6");
        e.printStackTrace();
    } catch (IllegalBlockSizeException e) {
        // TODO Auto-generated catch block
        Log.d("D","7");
        e.printStackTrace();
    } catch (BadPaddingException e) {
        // TODO Auto-generated catch block
        Log.d("D","8");
        e.printStackTrace();
    }

    ImageView im = (ImageView)findViewById(R.id.imageView2);

    Bitmap mainBitmap = BitmapFactory.decodeFile(dir+outFile);

    im.setImageBitmap(mainBitmap);

}

Answer 1

在 Java 版本中，与 Python 版本不同，在读取 IV 之前，您似乎不会读取文件大小。

您还可以打开第二个 FileInputStream，然后在分块读取 Cipher 之前不要跳过文件大小和 IV。

另一件需要检查的事情是键在 Java 和 Python 中的解释是相同的，即 Python 中的字符串与 Java 中的字节数组产生相同的字节序列。