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86 lines
2.7 KiB
86 lines
2.7 KiB
13 years ago
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# Copyright (c) 2002-2010 Zooko Wilcox-O'Hearn
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# This file is part of pyutil; see README.rst for licensing terms.
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import warnings
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import os, random
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try:
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import hashexpand
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class SHA256Random(hashexpand.SHA256Expander, random.Random):
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def __init__(self, seed=None, deterministic=True):
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warnings.warn("deprecated", DeprecationWarning)
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if not deterministic:
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raise NotImplementedError, "SHA256Expander is always deterministic. For non-deterministic, try urandomRandom."
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hashexpand.SHA256Expander.__init__(self)
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random.Random.__init__(self, seed)
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self.seed(seed)
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def seed(self, seed=None):
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if seed is None:
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import increasing_timer
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seed = repr(increasing_timer.time())
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hashexpand.SHA256Expander.seed(self, seed)
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class SHA256Random(hashexpand.SHA256Expander, random.Random):
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def __init__(self, seed=""):
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warnings.warn("deprecated", DeprecationWarning)
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hashexpand.SHA256Expander.__init__(self)
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self.seed(seed)
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def seed(self, seed=None):
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if seed is None:
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seed = os.urandom(32)
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hashexpand.SHA256Expander.seed(self, seed)
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except ImportError, le:
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class InsecureSHA256Random:
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def __init__(self, seed=None):
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raise ImportError, le
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class SHA256Random:
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def __init__(self, seed=""):
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raise ImportError, le
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class devrandomRandom(random.Random):
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""" The problem with using this one, of course, is that it blocks. This
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is, of course, a security flaw. (On Linux and probably on other
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systems.) --Zooko 2005-03-04
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Not repeatable.
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"""
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def __init__(self):
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warnings.warn("deprecated", DeprecationWarning)
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self.dr = open("/dev/random", "r")
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def get(self, bytes):
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return self.dr.read(bytes)
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class devurandomRandom(random.Random):
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""" The problem with using this one is that it gives answers even when it
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has never been properly seeded, e.g. when you are booting from CD and have
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just started up and haven't yet gathered enough entropy to actually be
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unguessable. (On Linux and probably on other systems.) --Zooko 2005-03-04
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Not repeatable.
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"""
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def get(self, bytes):
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warnings.warn("deprecated", DeprecationWarning)
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return os.urandom(bytes)
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randobj = devurandomRandom()
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get = randobj.get
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random = randobj.random
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randrange = randobj.randrange
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shuffle = randobj.shuffle
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choice = randobj.choice
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seed = randobj.seed
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def randstr(n):
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return ''.join(map(chr, map(randrange, [0]*n, [256]*n)))
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import random as insecurerandom
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def insecurerandstr(n):
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return ''.join(map(chr, map(insecurerandom.randrange, [0]*n, [256]*n)))
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