Input strings must be a multiple of 16 in length

[mattriley]

Hi. Does this code work on Windows?
I'm attempting to run it on:

• Windows 7
• Python 2.7
• PyCrypto 2.6 for Python 2.7
• A Keepass 1.24 database file

I get the following stack trace:

Traceback (most recent call last):
File "keepassc.py", line 10, in
cliobj()
File "./python\keepass\cli.py", line 78, in call
meth(cmdopts)
File "./python\keepass\cli.py", line 143, in _open
self.db = kpdb.Database(files[0],opts.masterkey)
File "./python\keepass\kpdb.py", line 29, in init
self.read(filename)
File "./python\keepass\kpdb.py", line 55, in read
self.header.encryption_iv)
File "./python\keepass\kpdb.py", line 99, in decrypt_payload
payload = self.decrypt_payload_aes_cbc(payload, finalkey, iv)
File "./python\keepass\kpdb.py", line 116, in decrypt_payload_aes_cbc
payload = cipher.decrypt(payload)
File "C:\Python27\lib\site-packages\Crypto\Cipher\blockalgo.py", line 295, in decrypt
return self._cipher.decrypt(ciphertext)
ValueError: Input strings must be a multiple of 16 in length

[brettviren]

I've not tested this on Windows. It was developed on Debian. The error you show does not look to me to be related to platform differences. It's been a while that I've used this code so maybe this multiple of 16 is a new requirement in the Crypto module(?).

Is it possible to zero-pad the ciphertext payload out to a multiple of 16 before the decrypt and recover the plaintext?

[Flumble]

Better late than never: I found the problem on Windows being that read() stops at EOF when the file is not explicitly opened in binary mode. See also http://stackoverflow.com/questions/9905874/python-does-not-read-entire-text-file
The payload of a database file must always be a multple of 16 bytes.

Opening the database with fp = open(filename, "rb") (kpdb.py:Database:read) solves the problem.