Java AES加密，Python解密不起作用

Question

I have tried multiple ways to do this, for three days now and many hours. I have gotten NO WHERE. I am using Java to encrypt certain data using AES/CBC/PKCS7Padding, and trying to decrypt using the same in Python but it just won't work. I am using this Python aes.py library http://anh.cs.luc.edu/331/code/aes.py
I am getting this error:

  File "/root/ascend/aes.py", line 384, in decrypt
  block[(i+(j*4))] = iput[(i*4)+j]
  exceptions.IndexError: list index out of range

Here is the Java Aes code:

    public String aesEncrypt(String key, String data) throws InvalidKeyException, BadPaddingException, IllegalBlockSizeException, NoSuchPaddingException, NoSuchAlgorithmException, UnsupportedEncodingException, InvalidAlgorithmParameterException {
          SecretKey secKey = new SecretKeySpec(key.getBytes(), "AES");
          KeyGenerator KeyGen = KeyGenerator.getInstance("AES");
          KeyGen.init(256);
          Cipher AesCipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
          AesCipher.init(Cipher.ENCRYPT_MODE, secKey, new IvParameterSpec(IV.getBytes("UTF-8")));
          byte[] byteCipherText = AesCipher.doFinal(data.getBytes());
          return Base64.encodeToString(byteCipherText, 0).trim();
    }

Here is the Java key gen which provides the key for python to use as well:

        public String genAESKey() {
          String uuid = UUID.randomUUID().toString();
          return uuid.replace("-","");
        }

And here is the python code to decrypt:

self.data = aes.decryptData(user.aes_key, base64.b64decode(self.data))
#Where user.aes_key is the 256bit Aes key generated by java.

Can someone please take a look and explain what is wrong with this? They are both using the same aes 256 key, pkcs7 padding, and CBC. If anyone knows of a better library that works with such java code please do show.

Edit: Just to clarify things, Aes decryption works in Java just not in python and Python encryption using that aes key works and so does python decryption. Just not java -> python. And self.data is the java encrypted aes data.

Edit #2: Just tried to do this with PyCrypto as well. Same exact error is occuring.

    return self._cipher.decrypt(ciphertext)
    exceptions.ValueError: Input strings must be a multiple of 16 in length

Answer 1

The problem was that for some reason Java was padding the first byte of the resulting String. Why? I don't have the slightest clue but after stripping it off in Python all was well. Both the PyCrypto code and the Aes.py code work fine.