AES解密错误：android pad块已损坏

Question

-IV是相同的，因为目前它是静态变量，用于测试目的。

-密码设置为AES/CBC/PKCS5Padding

-键设置为AES

    SharedPreferences sharedPreferences = context.getSharedPreferences(GENERATED_KEY, Context.MODE_PRIVATE);
    String keyStr = sharedPreferences.getString(GENERATED_KEY, null);
    if (keyStr == null) {
        final int outputKeyLength = 128;
        SecureRandom secureRandom = new SecureRandom();
        KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
        keyGenerator.init(outputKeyLength, secureRandom);
        SecretKey key = keyGenerator.generateKey();
        byte[] bytes = key.getEncoded();
        keyStr = Base64.encodeToString(bytes, Base64.DEFAULT);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.putString(GENERATED_KEY, keyStr);
        editor.commit();
        return key.toString();
    }  else {
        return keyStr;
    }

    connection = (HttpURLConnection) url.openConnection();
    connection.connect();
    SecretKey secretKey = getSecretKey(context);
    SecretKeySpec secretKeySpec = new SecretKeySpec(secretKey.getEncoded(), "AES");
    Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
    spec = generateIv(cipher.getBlockSize());
    cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, spec);

    input = connection.getInputStream();
    cis = new CipherInputStream(input, cipher);

    String FILEPATH = context.getFilesDir().getParentFile().getPath();
    File file = new File(FILEPATH, "/download/" + id + "/");
       if (!file.exists()) {
    file.mkdirs();
    }

    xmlFile = new File(FILEPATH + "/download/" + id + "/", "xmldata.xml");
    output = new FileOutputStream(xmlFile);
    cos = new CipherOutputStream(output, cipher);
    byte data[] = new byte[4096];
    int count;
    while ((count = cis.read(data)) != -1) {
       if (isCancelled()) throw new TaskCanceledException();
          cos.write(data, 0, count);
          progress = -1;
          publishProgress();
    }
    if (isCancelled()) throw new TaskCanceledException();

public String decryptXml() {
    String data = null;
    File file = new File(context.getFilesDir().getParentFile().getPath() + "/download/" + id + "/xmldata.xml");
    int size = (int) file.length();
    byte[] bytes = new byte[size];
 try {
        SecretKeySpec secretKeySpec = new SecretKeySpec(getSecretKey(context).getEncoded(), "AES");
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, DownloadBookAsyncTask.spec);
        BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));
        bis.read(bytes, 0, bytes.length);
        bis.close();
        byte[] decrypted = cipher.doFinal(bytes);
    }

public SecretKey getSecretKey(Context context){
    SharedPreferences sharedPreferences = context.getSharedPreferences(DashboardFragment.GENERATED_KEY, Context.MODE_PRIVATE);
    String stringKey = sharedPreferences.getString(DashboardFragment.GENERATED_KEY, null);
    byte[] encodedKey = Base64.decode(stringKey, Base64.DEFAULT);
    return new SecretKeySpec(encodedKey, 0, encodedKey.length, "AES");
}

编辑

添加IV发生器方法

public AlgorithmParameterSpec generateIv(int size) throws NoSuchAlgorithmException {
    AlgorithmParameterSpec ivspec;
    byte[] iv = new byte[size];
    new SecureRandom().nextBytes(iv);
    ivspec = new IvParameterSpec(iv);
    return ivspec;
}

Answer 1

好的，我找到问题了。我的代码不能工作的原因是我在加密中使用了CipherInputStream，我不应该这样做。我还重做了整个解密方法，现在看起来是这样的：

  byte[] wholeFileByte = null;
    Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
    cipher.init(Cipher.DECRYPT_MODE, key, DownloadBookAsyncTask.ivspec);
    File file = new File(context.getFilesDir().getParentFile().getPath() + "/download/" + id + "/xmldata.xml");
    FileInputStream fis = new FileInputStream(file);
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    CipherInputStream cis = new CipherInputStream(fis, cipher);
    byte data[] = new byte[4096];
    int count;
    while ((count = cis.read(data)) != -1) {
        bos.write(data, 0, count);
    }

    if(cis != null)
        cis.close();
    if(bos != null)
        bos.close();
    if(fis != null)
        fis.close();

    wholeFileByte = bos.toByteArray();
    String kk = new String(wholeFileByte, "UTF-8");

我认为我犯的另一个错误是，我在解密时使用了doFinal，即使密码已经完成了解密，这也是我的一些错误的来源。

感谢@Garibn，因为你让我走上了正确的道路，当我的代表允许我的时候，你会投你的赞成票：）