updated pycrypto
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@@ -38,21 +38,16 @@ __revision__ = "$Id$"
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import math
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import struct
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import sys
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if sys.version_info[0] == 2 and sys.version_info[1] == 1:
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from Crypto.Util.py21compat import *
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from Crypto.Util.py3compat import *
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from Crypto.Hash import SHA1, HMAC, CMAC
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from Crypto.Hash import SHA as SHA1, HMAC
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from Crypto.Util.strxor import strxor
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from Crypto.Util.number import long_to_bytes, bytes_to_long
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def PBKDF1(password, salt, dkLen, count=1000, hashAlgo=None):
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"""Derive one key from a password (or passphrase).
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This function performs key derivation according an old version of
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the PKCS#5 standard (v1.5).
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This algorithm is called ``PBKDF1``. Even though it is still described
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in the latest version of the PKCS#5 standard (version 2, or RFC2898),
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newer applications should use the more secure and versatile `PBKDF2` instead.
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@@ -81,7 +76,7 @@ def PBKDF1(password, salt, dkLen, count=1000, hashAlgo=None):
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pHash = hashAlgo.new(password+salt)
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digest = pHash.digest_size
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if dkLen>digest:
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raise TypeError("Selected hash algorithm has a too short digest (%d bytes)." % digest)
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raise ValueError("Selected hash algorithm has a too short digest (%d bytes)." % digest)
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if len(salt)!=8:
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raise ValueError("Salt is not 8 bytes long.")
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for i in xrange(count-1):
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@@ -126,84 +121,3 @@ def PBKDF2(password, salt, dkLen=16, count=1000, prf=None):
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i = i + 1
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return key[:dkLen]
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class _S2V(object):
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"""String-to-vector PRF as defined in `RFC5297`_.
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This class implements a pseudorandom function family
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based on CMAC that takes as input a vector of strings.
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.. _RFC5297: http://tools.ietf.org/html/rfc5297
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"""
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def __init__(self, key, ciphermod):
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"""Initialize the S2V PRF.
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:Parameters:
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key : byte string
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A secret that can be used as key for CMACs
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based on ciphers from ``ciphermod``.
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ciphermod : module
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A block cipher module from `Crypto.Cipher`.
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"""
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self._key = key
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self._ciphermod = ciphermod
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self._last_string = self._cache = bchr(0)*ciphermod.block_size
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self._n_updates = ciphermod.block_size*8-1
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def new(key, ciphermod):
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"""Create a new S2V PRF.
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:Parameters:
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key : byte string
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A secret that can be used as key for CMACs
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based on ciphers from ``ciphermod``.
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ciphermod : module
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A block cipher module from `Crypto.Cipher`.
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"""
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return _S2V(key, ciphermod)
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new = staticmethod(new)
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def _double(self, bs):
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doubled = bytes_to_long(bs)<<1
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if bord(bs[0]) & 0x80:
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doubled ^= 0x87
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return long_to_bytes(doubled, len(bs))[-len(bs):]
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def update(self, item):
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"""Pass the next component of the vector.
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The maximum number of components you can pass is equal to the block
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length of the cipher (in bits) minus 1.
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:Parameters:
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item : byte string
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The next component of the vector.
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:Raise TypeError: when the limit on the number of components has been reached.
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:Raise ValueError: when the component is empty
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"""
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if not item:
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raise ValueError("A component cannot be empty")
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if self._n_updates==0:
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raise TypeError("Too many components passed to S2V")
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self._n_updates -= 1
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mac = CMAC.new(self._key, msg=self._last_string, ciphermod=self._ciphermod)
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self._cache = strxor(self._double(self._cache), mac.digest())
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self._last_string = item
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def derive(self):
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""""Derive a secret from the vector of components.
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:Return: a byte string, as long as the block length of the cipher.
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"""
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if len(self._last_string)>=16:
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final = self._last_string[:-16] + strxor(self._last_string[-16:], self._cache)
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else:
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padded = (self._last_string + bchr(0x80)+ bchr(0)*15)[:16]
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final = strxor(padded, self._double(self._cache))
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mac = CMAC.new(self._key, msg=final, ciphermod=self._ciphermod)
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return mac.digest()
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