126 lines
3.9 KiB
Python
126 lines
3.9 KiB
Python
###############################################################################
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#
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# The MIT License (MIT)
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#
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# Copyright (c) Crossbar.io Technologies GmbH
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#
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# Permission is hereby granted, free of charge, to any person obtaining a copy
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# of this software and associated documentation files (the "Software"), to deal
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# in the Software without restriction, including without limitation the rights
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# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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# copies of the Software, and to permit persons to whom the Software is
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# furnished to do so, subject to the following conditions:
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#
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# The above copyright notice and this permission notice shall be included in
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# all copies or substantial portions of the Software.
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#
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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# THE SOFTWARE.
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#
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###############################################################################
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try:
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# use Cython implementation of XorMasker validator if available
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from wsaccel.xormask import XorMaskerNull
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# noinspection PyUnresolvedReferences
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from wsaccel.xormask import createXorMasker
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create_xor_masker = createXorMasker
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except ImportError:
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# fallback to pure Python implementation (this is faster on PyPy than above!)
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# http://stackoverflow.com/questions/15014310/python3-xrange-lack-hurts
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try:
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# noinspection PyUnresolvedReferences
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xrange
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except NameError:
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# Python 3
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# noinspection PyShadowingBuiltins
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xrange = range
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from array import array
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class XorMaskerNull(object):
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__slots__ = ('_ptr',)
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# noinspection PyUnusedLocal
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def __init__(self, mask=None):
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self._ptr = 0
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def pointer(self):
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return self._ptr
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def reset(self):
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self._ptr = 0
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def process(self, data):
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self._ptr += len(data)
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return data
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class XorMaskerSimple(object):
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__slots__ = ('_ptr', '_msk')
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def __init__(self, mask):
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assert len(mask) == 4
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self._ptr = 0
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self._msk = array('B', mask)
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def pointer(self):
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return self._ptr
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def reset(self):
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self._ptr = 0
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def process(self, data):
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dlen = len(data)
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payload = array('B', data)
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for k in xrange(dlen):
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payload[k] ^= self._msk[self._ptr & 3]
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self._ptr += 1
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return payload.tobytes()
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class XorMaskerShifted1(object):
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__slots__ = ('_ptr', '_mskarray')
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def __init__(self, mask):
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assert len(mask) == 4
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self._ptr = 0
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self._mskarray = [array('B'), array('B'), array('B'), array('B')]
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for j in xrange(4):
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self._mskarray[0].append(mask[j & 3])
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self._mskarray[1].append(mask[(j + 1) & 3])
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self._mskarray[2].append(mask[(j + 2) & 3])
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self._mskarray[3].append(mask[(j + 3) & 3])
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def pointer(self):
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return self._ptr
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def reset(self):
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self._ptr = 0
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def process(self, data):
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dlen = len(data)
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payload = array('B', data)
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msk = self._mskarray[self._ptr & 3]
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for k in xrange(dlen):
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payload[k] ^= msk[k & 3]
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self._ptr += dlen
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return payload.tobytes()
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def create_xor_masker(mask, length=None):
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if length is None or length < 128:
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return XorMaskerSimple(mask)
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else:
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return XorMaskerShifted1(mask)
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