java IllegalBlockSizeException：使用填充密码解密时，输入长度必须是8的倍数

Question

我有以下方法：

public String decrypt(String strToBeDecrypted) {
    try {
        strToBeDecrypted = URLDecoder.decode(strToBeDecrypted, "UTF-8");
        DESKeySpec desKeySpec = new DESKeySpec(key);
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey skey = keyFactory.generateSecret(desKeySpec);

        IvParameterSpec ivSpec = new IvParameterSpec(iv);

        cipher.init(Cipher.DECRYPT_MODE, skey, ivSpec);

        byte[] keyByteArray = new BASE64Decoder().decodeBuffer(strToBeDecrypted);

        byte[] original = cipher.doFinal(keyByteArray);

        return new String(original, "UTF-8");
    } catch (Exception e) {
        logger.error(ExceptionUtil.getDetailedMessage(e));
    }
    return "";
}

这是投掷

"name=javax.crypto.IllegalBlockSizeException;message=Input length must be multiple of 8 when decrypting with padded cipher;"

在下面一行：

 byte[] original = cipher.doFinal(keyByteArray);

谁能告诉我这里有什么问题吗

Answer 1

请用这个。这对我有用

public String decrypt(String message) throws Exception {
    final MessageDigest md = MessageDigest.getInstance("md5");
    final byte[] digestOfPassword = md.digest("HG58YZ3CR9"
            .getBytes("utf-8"));
    final byte[] keyBytes = Arrays.copyOf(digestOfPassword, 24);
    for (int j = 0, k = 16; j < 8;) {
        keyBytes[k++] = keyBytes[j++];
    }

    final SecretKey key = new SecretKeySpec(keyBytes, "DESede");
    final IvParameterSpec iv = new IvParameterSpec(new byte[8]);
    final Cipher decipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");
    decipher.init(Cipher.DECRYPT_MODE, key, iv);

    final byte[] encData = new sun.misc.BASE64Decoder().decodeBuffer(message);
    final byte[] plainText = decipher.doFinal(encData);

    return new String(plainText, "UTF-8");
}