def Crc32(frame) -> int:
#CRC32
polynomial = 0x104c11db6
crc = Crc(width=32,
poly=polynomial,
reflect_in=True,
xor_in=(1 << 32) - 1,
reflect_out=True,
xor_out=0x00)
crc_calc = crc.bit_by_bit(frame)
return crc_calc
def check_string(opt):
"""
Return the calculated CRC sum of a string.
"""
error = False
if opt.undefined_crc_parameters:
sys.stderr.write(
"{0:s}: error: undefined parameters\n".format(progname))
sys.exit(1)
if opt.algorithm == 0:
opt.algorithm = opt.algo_bit_by_bit | opt.algo_bit_by_bit_fast | opt.algo_table_driven
alg = Crc(width=opt.width,
poly=opt.poly,
reflect_in=opt.reflect_in,
xor_in=opt.xor_in,
reflect_out=opt.reflect_out,
xor_out=opt.xor_out,
table_idx_width=opt.tbl_idx_width)
crc = None
if opt.algorithm & opt.algo_bit_by_bit:
bbb_crc = alg.bit_by_bit(opt.check_string)
if crc != None and bbb_crc != crc:
error = True
crc = bbb_crc
if opt.algorithm & opt.algo_bit_by_bit_fast:
bbf_crc = alg.bit_by_bit_fast(opt.check_string)
if crc != None and bbf_crc != crc:
error = True
crc = bbf_crc
if opt.algorithm & opt.algo_table_driven:
# no point making the python implementation slower by using less than 8 bits as index.
opt.tbl_idx_width = 8
tbl_crc = alg.table_driven(opt.check_string)
if crc != None and tbl_crc != crc:
error = True
crc = tbl_crc
if error:
sys.stderr.write(
"{0:s}: error: different checksums!\n".format(progname))
if opt.algorithm & opt.algo_bit_by_bit:
sys.stderr.write(
" bit-by-bit: {0:#x}\n".format(bbb_crc))
if opt.algorithm & opt.algo_bit_by_bit_fast:
sys.stderr.write(
" bit-by-bit-fast: {0:#x}\n".format(bbf_crc))
if opt.algorithm & opt.algo_table_driven:
sys.stderr.write(
" table_driven: {0:#x}\n".format(tbl_crc))
sys.exit(1)
return crc
class CrcEncoder(object):
def __init__(self, model='dallas-1-wire'):
self.params = CrcModels().get_params(model)
self.encoder = Crc(self.params['width'],
self.params['poly'],
self.params['reflect_in'],
self.params['xor_in'],
self.params['reflect_out'],
self.params['xor_out'])
def encode(self, msg):
crc_hex = self.encoder.bit_by_bit(msg)
return chr(crc_hex) + msg
def __get_crc(self, model, check_str='123456789', expected_crc=None):
"""
Get the CRC for a set of parameters from the Python reference implementation.
"""
if self.verbose:
out_str = 'Crc(width = {width:d}, poly = {poly:#x}, reflect_in = {reflect_in}, xor_in = {xor_in:#x}, reflect_out = {reflect_out}, xor_out = {xor_out:#x})'.format(
**model)
if expected_crc is not None:
out_str += ' [check = {0:#x}]'.format(expected_crc)
print(out_str)
alg = Crc(width=model['width'],
poly=model['poly'],
reflect_in=model['reflect_in'],
xor_in=model['xor_in'],
reflect_out=model['reflect_out'],
xor_out=model['xor_out'])
error = False
crc = expected_crc
if self.use_algo_bit_by_bit:
bbb_crc = alg.bit_by_bit(check_str)
if crc is None:
crc = bbb_crc
error = error or bbb_crc != crc
if self.use_algo_bit_by_bit_fast:
bbf_crc = alg.bit_by_bit_fast(check_str)
if crc is None:
crc = bbf_crc
error = error or bbf_crc != crc
if self.use_algo_table_driven:
tbl_crc = alg.table_driven(check_str)
if crc is None:
crc = tbl_crc
error = error or tbl_crc != crc
if error:
print('error: different checksums!')
if expected_crc is not None:
print(' check: {0:#x}'.format(expected_crc))
if self.use_algo_bit_by_bit:
print(' bit-by-bit: {0:#x}'.format(bbb_crc))
if self.use_algo_bit_by_bit_fast:
print(' bit-by-bit-fast: {0:#x}'.format(bbf_crc))
if self.use_algo_table_driven:
print(' table_driven: {0:#x}'.format(tbl_crc))
return None
return crc
def check_string(opt):
"""
Return the calculated CRC sum of a string.
"""
error = False
if opt.undefined_crc_parameters:
sys.stderr.write("{0:s}: error: undefined parameters\n".format(progname))
sys.exit(1)
if opt.algorithm == 0:
opt.algorithm = opt.algo_bit_by_bit | opt.algo_bit_by_bit_fast | opt.algo_table_driven
alg = Crc(
width=opt.width, poly=opt.poly,
reflect_in=opt.reflect_in, xor_in=opt.xor_in,
reflect_out=opt.reflect_out, xor_out=opt.xor_out,
table_idx_width=opt.tbl_idx_width)
crc = None
if opt.algorithm & opt.algo_bit_by_bit:
bbb_crc = alg.bit_by_bit(opt.check_string)
if crc != None and bbb_crc != crc:
error = True
crc = bbb_crc
if opt.algorithm & opt.algo_bit_by_bit_fast:
bbf_crc = alg.bit_by_bit_fast(opt.check_string)
if crc != None and bbf_crc != crc:
error = True
crc = bbf_crc
if opt.algorithm & opt.algo_table_driven:
# no point making the python implementation slower by using less than 8 bits as index.
opt.tbl_idx_width = 8
tbl_crc = alg.table_driven(opt.check_string)
if crc != None and tbl_crc != crc:
error = True
crc = tbl_crc
if error:
sys.stderr.write("{0:s}: error: different checksums!\n".format(progname))
if opt.algorithm & opt.algo_bit_by_bit:
sys.stderr.write(" bit-by-bit: {0:#x}\n".format(bbb_crc))
if opt.algorithm & opt.algo_bit_by_bit_fast:
sys.stderr.write(" bit-by-bit-fast: {0:#x}\n".format(bbf_crc))
if opt.algorithm & opt.algo_table_driven:
sys.stderr.write(" table_driven: {0:#x}\n".format(tbl_crc))
sys.exit(1)
return crc
def __get_crc(self, model, check_str = '123456789', expected_crc = None):
"""
Get the CRC for a set of parameters from the Python reference implementation.
"""
if self.verbose:
out_str = 'Crc(width = {width:d}, poly = {poly:#x}, reflect_in = {reflect_in}, xor_in = {xor_in:#x}, reflect_out = {reflect_out}, xor_out = {xor_out:#x})'.format(**model)
if expected_crc is not None:
out_str += ' [check = {0:#x}]'.format(expected_crc)
print(out_str)
alg = Crc(width = model['width'], poly = model['poly'],
reflect_in = model['reflect_in'], xor_in = model['xor_in'],
reflect_out = model['reflect_out'], xor_out = model['xor_out'])
error = False
crc = expected_crc
if self.use_algo_bit_by_bit:
bbb_crc = alg.bit_by_bit(check_str)
if crc is None:
crc = bbb_crc
error = error or bbb_crc != crc
if self.use_algo_bit_by_bit_fast:
bbf_crc = alg.bit_by_bit_fast(check_str)
if crc is None:
crc = bbf_crc
error = error or bbf_crc != crc
if self.use_algo_table_driven:
tbl_crc = alg.table_driven(check_str)
if crc is None:
crc = tbl_crc
error = error or tbl_crc != crc
if error:
print('error: different checksums!')
if expected_crc is not None:
print(' check: {0:#x}'.format(expected_crc))
if self.use_algo_bit_by_bit:
print(' bit-by-bit: {0:#x}'.format(bbb_crc))
if self.use_algo_bit_by_bit_fast:
print(' bit-by-bit-fast: {0:#x}'.format(bbf_crc))
if self.use_algo_table_driven:
print(' table_driven: {0:#x}'.format(tbl_crc))
return None
return crc