Question

加密工作最佳，看起来文本在查看文件时似乎是加密的。我虽然坚持解密过程并且有错误：

＆＃34;线程中的异常＆＃34; main＆＃34;显示java.lang.NullPointerException 在java.util.Arrays.copyOfRange（Arrays.java:3521）＆＃34;

我用这个方法调用方法：

char [] password;
byte [] encrypted;
decrypt(input, new File(outFile),encrypted,password);

//解密方法

public void decrypt(File inputFile, File outputFile , byte [] encrypted, char [] password) throws Exception {

    byte[] iv = Arrays.copyOfRange(encrypted, 0, IV_SIZE_IN_BITS / 8);
     byte[] ciphertext = Arrays.copyOfRange(encrypted, iv.length, encrypted.length);



      Cipher cipher = initCipher(Cipher.DECRYPT_MODE, password,iv);
       FileOutputStream fos = null;
       CipherInputStream cis = null;
       FileInputStream fis = null;
       try {
           fis = new FileInputStream(inputFile);
           cis = new CipherInputStream(fis, cipher);
           fos = new FileOutputStream(outputFile);
           byte[] data = new byte[1024];
           int read = cis.read(data);
           while (read != -1) {
           fos.write(data, 0, read);
           read = cis.read(data);
           System.out.println(new String(data, "UTF-8").trim());
           }
       } finally {
           cis.close();
           fos.close();
           fis.close();
       }
}

NEW ---------

 private static final String KEY_DERIVATION_FUNCTION = "PBKDF2WithHmacSHA256";
  private static final String ENCRYPTION_ALGORITHM    = "AES";
  private static final String TRANSFORMATION          = "AES/GCM/NoPadding";
  private static final String GENERATOR_ALGORITHM     = "SHA1PRNG";

  private static final int KEY_SIZE_IN_BITS = 128;
  private static final int  IV_SIZE_IN_BITS = 128;
  private static final int TAG_SIZE_IN_BITS = 128;
  private static final int ITERATION_COUNT  = 200_000;





private static Cipher initCipher(int mode,char [] password, byte[] iv) {

    GCMParameterSpec gcmSpec = new GCMParameterSpec(TAG_SIZE_IN_BITS, iv);

    SecretKey key = deriveKey(password, iv);
    try {

      Cipher cipher = Cipher.getInstance(TRANSFORMATION);
      cipher.init(mode, key, gcmSpec);
      return cipher;
    }

    catch (
      NoSuchAlgorithmException |
      NoSuchPaddingException   |
      InvalidKeyException      |
      InvalidAlgorithmParameterException ex
    ) {
      throw new AssertionError(ex);
    }
 }

Answer 1

如果您真的使用此代码调用解密方法：

char [] password;
byte [] encrypted;
decrypt(input, new File(outFile),encrypted,password);

然后您的password和encrypted变量尚未初始化，并且均为空，因此为NullPointerException。您必须将变量设置为引用包含加密数据和密码的实际数组。

Answer 2

您没有使用以下命令指定加密算法，模式或填充：

Cipher cipher = initCipher(Cipher.DECRYPT_MODE, password,iv);

似乎它是默认的AES以外的算法，你想用什么算法？

始终准确指定您需要的内容，不要依赖默认值。我怀疑在你的情况下你需要算法：AES，模式：CBC，填充：PKCS＃7（有时指定PKCS＃5）。但这些必须与加密完全匹配。还为密钥和iv提供所需的精确长度，密钥长度使用128位，192位或256位（16字节24字节或32字节）和iv 16字节。

错误javax.crypto.AEADBadTagException表示：

当以AEAD模式运行的密码（例如GCM / CCM）无法验证提供的身份验证标记时，抛出此异常。

Answer 3

来自Java文档Java.util.Arrays.copyOfRange()的错误import csv, sympy import sympy as sym fw = open('polyexp.csv', "w") fr = open('polyval.csv', "r") a,b,c, d, e= sympy.symbols("a b c d e") formula = (a+b+c+d+e) ** 3 poly = str(formula.expand()) ls = poly.split('+') for i in range(len(ls)): ls_val[i] = sym.sympify(ls[i]) for line in fr: tup = line.split(",") csvrow = list() for key in range(len(ls_val)): new = ls_val[key].subs([(a, tup[0]),(b,tup[1]),(c,tup[2]),(d,tup[3]),(e,tup[4])]) csvrow.append(new) print >> fw, csvrow：

NullPointerException - 如果original为null。

检查实际数据长度与请求的范围。同时验证java.lang.NullPointerException，IV_SIZE_IN_BITS和iv.length的值。

AES解密错误

3 个答案: