Question

我正在尝试使用AES加密和解密字符串，但收到错误我不知道如何解决。这是代码：

public class EncryptionTest{

public static void main(String[] args) {        
    String encrypt = new String(encrypt("1234567890123456"));
    System.out.println("decrypted value:" + (decrypt("ThisIsASecretKey",encrypt)));
}

public static String encrypt(String value) {
    try {
        byte[] raw = new byte[]{'T', 'h', 'i', 's', 'I', 's', 'A', 'S', 'e', 'c', 'r', 'e', 't', 'K', 'e', 'y'};
        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
        byte[] encrypted = cipher.doFinal(value.getBytes());
        System.out.println("encrypted string:" + (new String(encrypted)));
        return new String(skeySpec.getEncoded());
    } catch (Exception ex) {
        ex.printStackTrace();
    }
    return null;
}

public static String decrypt(String key, String encrypted) {
    try {
        SecretKeySpec skeySpec = new SecretKeySpec(Base64.decodeBase64(key), "AES");
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(skeySpec.getEncoded(),"AES"));
            (*)
        byte[] original = cipher.doFinal(Base64.decodeBase64(encrypted));
        original.toString();
    } catch (Exception ex) {
        ex.printStackTrace();
    }
    return null;
}  
}

当我运行它时，“decription”值为null。它在（***）!!

之前失败了

它给了我一个例外：

java.security.InvalidKeyException: Parameters missing
    at com.sun.crypto.provider.CipherCore.init(CipherCore.java:388)
    at com.sun.crypto.provider.AESCipher.engineInit(AESCipher.java:186)
    at javax.crypto.Cipher.implInit(Cipher.java:787)
    at javax.crypto.Cipher.chooseProvider(Cipher.java:849)
    at javax.crypto.Cipher.init(Cipher.java:1213)
    at javax.crypto.Cipher.init(Cipher.java:1153)
    at firma.XmlEncryptionTest.decrypt(EncryptionTest.java:63)
    at firma.XmlEncryptionTest.main(EncryptionTest.java:41)

其中第63行是之前的（***）。我不知道我做错了什么以及如何解决。我在互联网上环顾四周，但没有发现什么可能是缺少参数

Answer 1

代码中的主要问题是由于未能指定IV值。您必须在执行CBC模式加密时指定IV值，并在执行CBC模式解密时使用相同的值。

另一个问题是从字节数组和base64编码创建字符串的混合和匹配。您每次都会从解密方法返回null。即使您的意思是return original.toString();，这仍然是错误的（因为toString()不能按照您希望的那样在字节数组上执行。）

以下是代码的改进版本。它远非最佳，但它编译和工作。你需要改进这个以使用随机IV。 此外，如果您计划从密码派生密钥，请不要只获取字节，使用派生函数，如PBKDF2 。您可以在JNCryptor source中看到使用PBKDF2的示例。

public class EncryptionTest {

  public static void main(String[] args) {
    try {

      String key = "ThisIsASecretKey";
      byte[] ciphertext = encrypt(key, "1234567890123456");
      System.out.println("decrypted value:" + (decrypt(key, ciphertext)));

    } catch (GeneralSecurityException e) {
      e.printStackTrace();
    }
  }

  public static byte[] encrypt(String key, String value)
      throws GeneralSecurityException {

    byte[] raw = key.getBytes(Charset.forName("UTF-8"));
    if (raw.length != 16) {
      throw new IllegalArgumentException("Invalid key size.");
    }

    SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
    Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
    cipher.init(Cipher.ENCRYPT_MODE, skeySpec,
        new IvParameterSpec(new byte[16]));
    return cipher.doFinal(value.getBytes(Charset.forName("UTF-8")));
  }

  public static String decrypt(String key, byte[] encrypted)
      throws GeneralSecurityException {

    byte[] raw = key.getBytes(Charset.forName("UTF-8"));
    if (raw.length != 16) {
      throw new IllegalArgumentException("Invalid key size.");
    }
    SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");

    Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
    cipher.init(Cipher.DECRYPT_MODE, skeySpec,
        new IvParameterSpec(new byte[16]));
    byte[] original = cipher.doFinal(encrypted);

    return new String(original, Charset.forName("UTF-8"));
  }
}

Answer 2

如果您使用像CBC这样的块链接模式，您还需要为Cipher提供IvParameterSpec。

public class EncryptionTest {

static byte[] raw = new byte[]{'T', 'h', 'i', 's', 'I', 's', 'A', 'S', 'e', 'c', 'r', 'e', 't', 'K', 'e', 'y'};

static SecureRandom rnd = new SecureRandom();

static IvParameterSpec iv = new IvParameterSpec(rnd.generateSeed(16));

public static void main(String[] args) {
    String encrypt = encrypt("1234567890123456");
    System.out.println("decrypted value:" + (decrypt("ThisIsASecretKey", encrypt)));
}

public static String encrypt(String value) {
    try {

        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec,iv);
        byte[] encrypted = cipher.doFinal(value.getBytes());
        System.out.println("encrypted string:" + Base64.encodeBase64String(encrypted));
        return Base64.encodeBase64String(encrypted);
    } catch (Exception ex) {
        ex.printStackTrace();
    }
    return null;
}

public static String decrypt(String key, String encrypted) {
    try {
        SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes(), "AES");
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
        cipher.init(Cipher.DECRYPT_MODE, skeySpec,iv);
        byte[] original = cipher.doFinal(Base64.decodeBase64(encrypted));

        return new String(original);
    } catch (Exception ex) {
        ex.printStackTrace();
    }
    return null;
}

}

Answer 3

尽管为时已晚，但我仍在为其他人提供解决方案。请参考以下工作代码加密和解密数据。

public static byte[] encrypt(String value) {
        byte[] encrypted = null;
        try {

            byte[] raw = new byte[]{'T', 'h', 'i', 's', 'I', 's', 'A', 'S', 'e', 'c', 'r', 'e', 't', 'K', 'e', 'y'};
            Key skeySpec = new SecretKeySpec(raw, "AES");
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            byte[] iv = new byte[cipher.getBlockSize()];

            IvParameterSpec ivParams = new IvParameterSpec(iv);
            cipher.init(Cipher.ENCRYPT_MODE, skeySpec,ivParams);
            encrypted  = cipher.doFinal(value.getBytes());
            System.out.println("encrypted string:" + encrypted.length);

        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return encrypted;
    }

    public static  byte[]  decrypt(byte[] encrypted) {
         byte[] original = null;
         Cipher cipher = null;
        try {
            byte[] raw = new byte[]{'T', 'h', 'i', 's', 'I', 's', 'A', 'S', 'e', 'c', 'r', 'e', 't', 'K', 'e', 'y'};
            Key key = new SecretKeySpec(raw, "AES");
            cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            //the block size (in bytes), or 0 if the underlying algorithm is not a block cipher
            byte[] ivByte = new byte[cipher.getBlockSize()];
            //This class specifies an initialization vector (IV). Examples which use
            //IVs are ciphers in feedback mode, e.g., DES in CBC mode and RSA ciphers with OAEP encoding operation.
            IvParameterSpec ivParamsSpec = new IvParameterSpec(ivByte);
            cipher.init(Cipher.DECRYPT_MODE, key, ivParamsSpec);
            original= cipher.doFinal(encrypted);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return original;
    }

导致错误的原因＆＃34; java.security.InvalidKeyException：缺少参数＆＃34;？

3 个答案: