Giovannetti, Mark wrote:
From: Dmitry Vasiliev [mailto:[EMAIL PROTECTED]
Slices doesn't wrap around.


Right, this was what I was seeing/thinking about:

for i in range(41): print i, "'" + "password"[:i-40] + "'"
[skip]
Can't really call it wrap around, I guess.
Anyway:
    def checkPassword(self, storedPassword, password):
        salt = storedPassword[:max(0, len(storedPassword)-40)]
        return storedPassword == self.encodePassword(password, salt)
With Python you can do things as simply as possible. :-) The expression
storedPassword[:-40] (which is equivalent to
storedPassword[:len(storedPassword)-40]) does exactly what you want:

 >>> "password"[:-40]
''

Keeping it simple is often the best way.  Given the above, in order
to ensure a blank salt with a password less than 40 characters,
keeping it simple may not suffice.

I think in the example above you're testing for wrong use case since we use constant slice index, the following example explains what I mean:

>>> hash = "123456789"
>>> while hash:
...     print (hash[:-4], hash[-4:])
...     hash = hash[1:]
...
('12345', '6789')
('2345', '6789')
('345', '6789')
('45', '6789')
('5', '6789')
('', '6789')
('', '789')
('', '89')
('', '9')

--
Dmitry Vasiliev <dima at hlabs.spb.ru>
http://hlabs.spb.ru
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