File: //opt/gsutil/third_party/crcmod/python2/crcmod/test.py
#-----------------------------------------------------------------------------
# Copyright (c) 2010 Raymond L. Buvel
# Copyright (c) 2010 Craig McQueen
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#-----------------------------------------------------------------------------
'''Unit tests for crcmod functionality'''
import unittest
import binascii
from crcmod import mkCrcFun, Crc
try:
from crcmod.crcmod import _usingExtension
from crcmod.predefined import PredefinedCrc
from crcmod.predefined import mkPredefinedCrcFun
from crcmod.predefined import _crc_definitions as _predefined_crc_definitions
except ImportError:
from crcmod import _usingExtension
from predefined import PredefinedCrc
from predefined import mkPredefinedCrcFun
from predefined import _crc_definitions as _predefined_crc_definitions
#-----------------------------------------------------------------------------
# This polynomial was chosen because it is the product of two irreducible
# polynomials.
# g8 = (x^7+x+1)*(x+1)
g8 = 0x185
#-----------------------------------------------------------------------------
# The following reproduces all of the entries in the Numerical Recipes table.
# This is the standard CCITT polynomial.
g16 = 0x11021
#-----------------------------------------------------------------------------
g24 = 0x15D6DCB
#-----------------------------------------------------------------------------
# This is the standard AUTODIN-II polynomial which appears to be used in a
# wide variety of standards and applications.
g32 = 0x104C11DB7
#-----------------------------------------------------------------------------
# I was able to locate a couple of 64-bit polynomials on the web. To make it
# easier to input the representation, define a function that builds a
# polynomial from a list of the bits that need to be turned on.
def polyFromBits(bits):
p = 0L
for n in bits:
p = p | (1L << n)
return p
# The following is from the paper "An Improved 64-bit Cyclic Redundancy Check
# for Protein Sequences" by David T. Jones
g64a = polyFromBits([64, 63, 61, 59, 58, 56, 55, 52, 49, 48, 47, 46, 44, 41,
37, 36, 34, 32, 31, 28, 26, 23, 22, 19, 16, 13, 12, 10, 9, 6, 4,
3, 0])
# The following is from Standard ECMA-182 "Data Interchange on 12,7 mm 48-Track
# Magnetic Tape Cartridges -DLT1 Format-", December 1992.
g64b = polyFromBits([64, 62, 57, 55, 54, 53, 52, 47, 46, 45, 40, 39, 38, 37,
35, 33, 32, 31, 29, 27, 24, 23, 22, 21, 19, 17, 13, 12, 10, 9, 7,
4, 1, 0])
#-----------------------------------------------------------------------------
# This class is used to check the CRC calculations against a direct
# implementation using polynomial division.
class poly:
'''Class implementing polynomials over the field of integers mod 2'''
def __init__(self,p):
p = long(p)
if p < 0: raise ValueError('invalid polynomial')
self.p = p
def __long__(self):
return self.p
def __eq__(self,other):
return self.p == other.p
def __ne__(self,other):
return self.p != other.p
# To allow sorting of polynomials, use their long integer form for
# comparison
def __cmp__(self,other):
return cmp(self.p, other.p)
def __nonzero__(self):
return self.p != 0L
def __neg__(self):
return self # These polynomials are their own inverse under addition
def __invert__(self):
n = max(self.deg() + 1, 1)
x = (1L << n) - 1
return poly(self.p ^ x)
def __add__(self,other):
return poly(self.p ^ other.p)
def __sub__(self,other):
return poly(self.p ^ other.p)
def __mul__(self,other):
a = self.p
b = other.p
if a == 0 or b == 0: return poly(0)
x = 0L
while b:
if b&1:
x = x ^ a
a = a<<1
b = b>>1
return poly(x)
def __divmod__(self,other):
u = self.p
m = self.deg()
v = other.p
n = other.deg()
if v == 0: raise ZeroDivisionError('polynomial division by zero')
if n == 0: return (self,poly(0))
if m < n: return (poly(0),self)
k = m-n
a = 1L << m
v = v << k
q = 0L
while k > 0:
if a & u:
u = u ^ v
q = q | 1L
q = q << 1
a = a >> 1
v = v >> 1
k -= 1
if a & u:
u = u ^ v
q = q | 1L
return (poly(q),poly(u))
def __div__(self,other):
return self.__divmod__(other)[0]
def __mod__(self,other):
return self.__divmod__(other)[1]
def __repr__(self):
return 'poly(0x%XL)' % self.p
def __str__(self):
p = self.p
if p == 0: return '0'
lst = { 0:[], 1:['1'], 2:['x'], 3:['1','x'] }[p&3]
p = p>>2
n = 2
while p:
if p&1: lst.append('x^%d' % n)
p = p>>1
n += 1
lst.reverse()
return '+'.join(lst)
def deg(self):
'''return the degree of the polynomial'''
a = self.p
if a == 0: return -1
n = 0
while a >= 0x10000L:
n += 16
a = a >> 16
a = int(a)
while a > 1:
n += 1
a = a >> 1
return n
#-----------------------------------------------------------------------------
# The following functions compute the CRC using direct polynomial division.
# These functions are checked against the result of the table driven
# algorithms.
g8p = poly(g8)
x8p = poly(1L<<8)
def crc8p(d):
d = map(ord, d)
p = 0L
for i in d:
p = p*256L + i
p = poly(p)
return long(p*x8p%g8p)
g16p = poly(g16)
x16p = poly(1L<<16)
def crc16p(d):
d = map(ord, d)
p = 0L
for i in d:
p = p*256L + i
p = poly(p)
return long(p*x16p%g16p)
g24p = poly(g24)
x24p = poly(1L<<24)
def crc24p(d):
d = map(ord, d)
p = 0L
for i in d:
p = p*256L + i
p = poly(p)
return long(p*x24p%g24p)
g32p = poly(g32)
x32p = poly(1L<<32)
def crc32p(d):
d = map(ord, d)
p = 0L
for i in d:
p = p*256L + i
p = poly(p)
return long(p*x32p%g32p)
g64ap = poly(g64a)
x64p = poly(1L<<64)
def crc64ap(d):
d = map(ord, d)
p = 0L
for i in d:
p = p*256L + i
p = poly(p)
return long(p*x64p%g64ap)
g64bp = poly(g64b)
def crc64bp(d):
d = map(ord, d)
p = 0L
for i in d:
p = p*256L + i
p = poly(p)
return long(p*x64p%g64bp)
class KnownAnswerTests(unittest.TestCase):
test_messages = [
'T',
'CatMouse987654321',
]
known_answers = [
[ (g8,0,0), (0xFE, 0x9D) ],
[ (g8,-1,1), (0x4F, 0x9B) ],
[ (g8,0,1), (0xFE, 0x62) ],
[ (g16,0,0), (0x1A71, 0xE556) ],
[ (g16,-1,1), (0x1B26, 0xF56E) ],
[ (g16,0,1), (0x14A1, 0xC28D) ],
[ (g24,0,0), (0xBCC49D, 0xC4B507) ],
[ (g24,-1,1), (0x59BD0E, 0x0AAA37) ],
[ (g24,0,1), (0xD52B0F, 0x1523AB) ],
[ (g32,0,0), (0x6B93DDDB, 0x12DCA0F4) ],
[ (g32,0xFFFFFFFFL,1), (0x41FB859FL, 0xF7B400A7L) ],
[ (g32,0,1), (0x6C0695EDL, 0xC1A40EE5L) ],
[ (g32,0,1,0xFFFFFFFF), (0xBE047A60L, 0x084BFF58L) ],
]
def test_known_answers(self):
for crcfun_params, v in self.known_answers:
crcfun = mkCrcFun(*crcfun_params)
self.assertEqual(crcfun('',0), 0, "Wrong answer for CRC parameters %s, input ''" % (crcfun_params,))
for i, msg in enumerate(self.test_messages):
self.assertEqual(crcfun(msg), v[i], "Wrong answer for CRC parameters %s, input '%s'" % (crcfun_params,msg))
self.assertEqual(crcfun(msg[4:], crcfun(msg[:4])), v[i], "Wrong answer for CRC parameters %s, input '%s'" % (crcfun_params,msg))
self.assertEqual(crcfun(msg[-1:], crcfun(msg[:-1])), v[i], "Wrong answer for CRC parameters %s, input '%s'" % (crcfun_params,msg))
class CompareReferenceCrcTest(unittest.TestCase):
test_messages = [
'',
'T',
'123456789',
'CatMouse987654321',
]
test_poly_crcs = [
[ (g8,0,0), crc8p ],
[ (g16,0,0), crc16p ],
[ (g24,0,0), crc24p ],
[ (g32,0,0), crc32p ],
[ (g64a,0,0), crc64ap ],
[ (g64b,0,0), crc64bp ],
]
@staticmethod
def reference_crc32(d, crc=0):
"""This function modifies the return value of binascii.crc32
to be an unsigned 32-bit value. I.e. in the range 0 to 2**32-1."""
# Work around the future warning on constants.
if crc > 0x7FFFFFFFL:
x = int(crc & 0x7FFFFFFFL)
crc = x | -2147483648
x = binascii.crc32(d,crc)
return long(x) & 0xFFFFFFFFL
def test_compare_crc32(self):
"""The binascii module has a 32-bit CRC function that is used in a wide range
of applications including the checksum used in the ZIP file format.
This test compares the CRC-32 implementation of this crcmod module to
that of binascii.crc32."""
# The following function should produce the same result as
# self.reference_crc32 which is derived from binascii.crc32.
crc32 = mkCrcFun(g32,0,1,0xFFFFFFFF)
for msg in self.test_messages:
self.assertEqual(crc32(msg), self.reference_crc32(msg))
def test_compare_poly(self):
"""Compare various CRCs of this crcmod module to a pure
polynomial-based implementation."""
for crcfun_params, crc_poly_fun in self.test_poly_crcs:
# The following function should produce the same result as
# the associated polynomial CRC function.
crcfun = mkCrcFun(*crcfun_params)
for msg in self.test_messages:
self.assertEqual(crcfun(msg), crc_poly_fun(msg))
class CrcClassTest(unittest.TestCase):
"""Verify the Crc class"""
msg = 'CatMouse987654321'
def test_simple_crc32_class(self):
"""Verify the CRC class when not using xorOut"""
crc = Crc(g32)
str_rep = \
'''poly = 0x104C11DB7
reverse = True
initCrc = 0xFFFFFFFF
xorOut = 0x00000000
crcValue = 0xFFFFFFFF'''
self.assertEqual(str(crc), str_rep)
self.assertEqual(crc.digest(), '\xff\xff\xff\xff')
self.assertEqual(crc.hexdigest(), 'FFFFFFFF')
crc.update(self.msg)
self.assertEqual(crc.crcValue, 0xF7B400A7L)
self.assertEqual(crc.digest(), '\xf7\xb4\x00\xa7')
self.assertEqual(crc.hexdigest(), 'F7B400A7')
# Verify the .copy() method
x = crc.copy()
self.assertTrue(x is not crc)
str_rep = \
'''poly = 0x104C11DB7
reverse = True
initCrc = 0xFFFFFFFF
xorOut = 0x00000000
crcValue = 0xF7B400A7'''
self.assertEqual(str(crc), str_rep)
self.assertEqual(str(x), str_rep)
def test_full_crc32_class(self):
"""Verify the CRC class when using xorOut"""
crc = Crc(g32, initCrc=0, xorOut= ~0L)
str_rep = \
'''poly = 0x104C11DB7
reverse = True
initCrc = 0x00000000
xorOut = 0xFFFFFFFF
crcValue = 0x00000000'''
self.assertEqual(str(crc), str_rep)
self.assertEqual(crc.digest(), '\x00\x00\x00\x00')
self.assertEqual(crc.hexdigest(), '00000000')
crc.update(self.msg)
self.assertEqual(crc.crcValue, 0x84BFF58L)
self.assertEqual(crc.digest(), '\x08\x4b\xff\x58')
self.assertEqual(crc.hexdigest(), '084BFF58')
# Verify the .copy() method
x = crc.copy()
self.assertTrue(x is not crc)
str_rep = \
'''poly = 0x104C11DB7
reverse = True
initCrc = 0x00000000
xorOut = 0xFFFFFFFF
crcValue = 0x084BFF58'''
self.assertEqual(str(crc), str_rep)
self.assertEqual(str(x), str_rep)
# Verify the .new() method
y = crc.new()
self.assertTrue(y is not crc)
self.assertTrue(y is not x)
str_rep = \
'''poly = 0x104C11DB7
reverse = True
initCrc = 0x00000000
xorOut = 0xFFFFFFFF
crcValue = 0x00000000'''
self.assertEqual(str(y), str_rep)
class PredefinedCrcTest(unittest.TestCase):
"""Verify the predefined CRCs"""
test_messages_for_known_answers = [
'', # Test cases below depend on this first entry being the empty string.
'T',
'CatMouse987654321',
]
known_answers = [
[ 'crc-aug-ccitt', (0x1D0F, 0xD6ED, 0x5637) ],
[ 'x-25', (0x0000, 0xE4D9, 0x0A91) ],
[ 'crc-32', (0x00000000, 0xBE047A60, 0x084BFF58) ],
]
def test_known_answers(self):
for crcfun_name, v in self.known_answers:
crcfun = mkPredefinedCrcFun(crcfun_name)
self.assertEqual(crcfun('',0), 0, "Wrong answer for CRC '%s', input ''" % crcfun_name)
for i, msg in enumerate(self.test_messages_for_known_answers):
self.assertEqual(crcfun(msg), v[i], "Wrong answer for CRC %s, input '%s'" % (crcfun_name,msg))
self.assertEqual(crcfun(msg[4:], crcfun(msg[:4])), v[i], "Wrong answer for CRC %s, input '%s'" % (crcfun_name,msg))
self.assertEqual(crcfun(msg[-1:], crcfun(msg[:-1])), v[i], "Wrong answer for CRC %s, input '%s'" % (crcfun_name,msg))
def test_class_with_known_answers(self):
for crcfun_name, v in self.known_answers:
for i, msg in enumerate(self.test_messages_for_known_answers):
crc1 = PredefinedCrc(crcfun_name)
crc1.update(msg)
self.assertEqual(crc1.crcValue, v[i], "Wrong answer for crc1 %s, input '%s'" % (crcfun_name,msg))
crc2 = crc1.new()
# Check that crc1 maintains its same value, after .new() call.
self.assertEqual(crc1.crcValue, v[i], "Wrong state for crc1 %s, input '%s'" % (crcfun_name,msg))
# Check that the new class instance created by .new() contains the initialisation value.
# This depends on the first string in self.test_messages_for_known_answers being
# the empty string.
self.assertEqual(crc2.crcValue, v[0], "Wrong state for crc2 %s, input '%s'" % (crcfun_name,msg))
crc2.update(msg)
# Check that crc1 maintains its same value, after crc2 has called .update()
self.assertEqual(crc1.crcValue, v[i], "Wrong state for crc1 %s, input '%s'" % (crcfun_name,msg))
# Check that crc2 contains the right value after calling .update()
self.assertEqual(crc2.crcValue, v[i], "Wrong state for crc2 %s, input '%s'" % (crcfun_name,msg))
def test_function_predefined_table(self):
for table_entry in _predefined_crc_definitions:
# Check predefined function
crc_func = mkPredefinedCrcFun(table_entry['name'])
calc_value = crc_func("123456789")
self.assertEqual(calc_value, table_entry['check'], "Wrong answer for CRC '%s'" % table_entry['name'])
def test_class_predefined_table(self):
for table_entry in _predefined_crc_definitions:
# Check predefined class
crc1 = PredefinedCrc(table_entry['name'])
crc1.update("123456789")
self.assertEqual(crc1.crcValue, table_entry['check'], "Wrong answer for CRC '%s'" % table_entry['name'])
def runtests():
print "Using extension:", _usingExtension
print
unittest.main()
if __name__ == '__main__':
runtests()