ValueError: Input strings must be a multiple of 16 in length

[daxdebor1]

Hello,
I am a bit noob here, but trying to use pywallet to decrypt wallet.dat.
Password is right, I know, checked in corecrypto.
But when trying to dumpwallet with passphrase:
Traceback (most recent call last):
File "pywallet.py", line 3592, in
read_wallet(json_db, db_env, wallet_name, True, True, "", options.dumpbalanc
e is not None)
File "pywallet.py", line 2555, in read_wallet
secret = crypter.Decrypt(ckey)
File "pywallet.py", line 739, in Decrypt
return AES.new(self.chKey,AES.MODE_CBC,self.chIV).decrypt(data)[0:32]
File "D:\Bitcoin\Python\lib\site-packages\Crypto\Cipher\blockalgo.py", line 29
5, in decrypt
return self._cipher.decrypt(ciphertext)
ValueError: Input strings must be a multiple of 16 in length

I am running the python 2.7 with pycrypto and last pywallet from jackjack.
I know, the problem is probably not with pywallet, but AES, but any advice is very welcome.

p.s. running on windows.

Thanks! Dax

[jackjack-jj]

Hi, what is the version of your wallet? Is it bitcoin-core?
Could you send me a new, empty wallet that triggers the bug?

[daxdebor1]

Hi JackJack,
yes, its bitcoin-core, various versions, tried as well fixwallet.py etc.
The passphrase is correct, when I write a wrong1 into pywallet.py, it says encrypted and pass incorrect.
when I write the correct, it writes mentioned ValueError. I do not have the new, empty that triggers the bug.
Edit: I tried as well several Pywallets. Most of them have the same Error. Just Pywallet SSL wrote "NameError: global name 'ctypes' is not defined" and Pywallet Crypter pure wrote "IndexError: list index out of range"
Any ideas? Sorry for spamming. :)
Thanks, Dax.

[jackjack-jj]

Sorry, didn't get the notification
FWIW I just pushed a version with a bit less stupid crypter loading
Now for your problem, I get a segfault with the SSL crypter so let's focus on the 2 other ones

For pycrypto, I don't get where the problem is as the data is padded using append_PKCS7_padding
You could replace it with that though to see what you get:

def append_PKCS7_padding(s):
	"""return s padded to a multiple of 16-bytes by PKCS7 padding"""
	numpads = 16 - (len(s)%16)
	r = s + numpads*chr(numpads)
	print(repr(r))
	return r

Does the string has a size of a multiple of 16? It sounds like a Windows encoding-related bug but that's strange I never heard of that before
I'll try that on Windows when I have a chance

Can you post the entire traceback of the crypto pure error?

[daxdebor1]

Hello JackJack,
thanks for your reply.
I downloaded your last version of pywallet.py (updated ca 2 days ago).
I changed the padding as your recommendation.
the message same as following:
Traceback (most recent call last):
File "D:\Bitcoin\Python\pywalletpo.py", line 3923, in
read_wallet(json_db, db_env, wallet_name, True, True, "", not(options.dumpba
lance is None))
File "D:\Bitcoin\Python\pywalletpo.py", line 2775, in read_wallet
secret = crypter.Decrypt(ckey)
File "D:\Bitcoin\Python\pywalletpo.py", line 908, in Decrypt
return AES.new(self.chKey,AES.MODE_CBC,self.chIV).decrypt(data)[0:32]
File "D:\bitcoin\Python\lib\site-packages\Crypto\Cipher\blockalgo.py", line 29
5, in decrypt
return self._cipher.decrypt(ciphertext)
ValueError: Input strings must be a multiple of 16 in length

To be honest, I am not that skilled, not sure, how to check the padding.
I do have the Python 2.7. and pycrypto-2.6.win-amd64-py2.7.
A bit strange, the mentioned blockalgo.py and overall Crypto Cipher is from 2012. Not sure if there might be a newer version?
I really appreciate your support.
If you prefer, please, do not hesitate to contact me on my e-mail: daxdebor@gmail.com and we could discuss faster and in more details.
Thanks.
Dax