CRCx 0.0.4

Extensive CRC

CRCx

Extensive Cyclic Redundancy Check

Work in progress…

Examples

import crc_rc3 as crc
import crc_rc3.catalog
import crc_rc3.engines.generic
import crc_rc3.engines.tableized
import crc_rc3.tables
import zlib


data = b"123456789"
data_a = b"12345"
data_b = b"6789"
check = 0xcbf43926  # crc from crc32 algorithm for the str '123456789


"""
simple usage
        select cataloged algorithm
        parse your input data
"""
calc = crc.create(crc.catalog.crc_32())
hash_a = calc.calc(data)


"""
calculate from multiple strings of input
        via instantiate object from the calculator class
"""
calc = crc.create(crc.catalog.crc_32())
inst = calc()
inst.process(data_a)  # process, update
hash_b = inst.final()  # you can check the result halfway through the calculation
inst.process(data_b)
hash_c = inst.final()  # result, final


# todo check if is big endian
"""
if you need the hash in bytes
        big endian
"""
# hash_d = calc.calc_bytes(data)
# or
# hash_e = inst.final_bytes()


"""
create the crc table manually
"""
# table for crc32
table = crc.tables.new_lsbf(0x04c11db7, 32)
# repr it so you can put in your own code
print(crc.tables.table_repr(32, 80)(table))


"""
define your own parameters
        option to select engine algorithm
"""
# params for crc32
params = crc.new(
        # required
        width=32,
        poly=0x04c11db7,
        init=0xffffffff,
        xorout=0xffffffff,
        refin=True,
        refout=True,
        # optional
        name="crc32",
        aliases=("alias_1", "alias_2"),
        desc="description",
        table=table,  # you can manually insert table here to avoid it being
        #  calculated automatically every time your program starts
)
calc = crc.create(params)
hash_f = calc.calc(data)


"""
use a different engine
        tableized is fastest engine but creates a table of 256 values
                this is the default
        generic doesn't create a table, but is slower
"""
# engine = crc.engines.generic
engine = crc.engines.tableized
calc = crc.create(params, engine)
hash_g = calc.calc(data)


"""
use the engine directly
        no 'convenience objects'
"""
# NotImplemented


"""
test
"""
hashes = check, zlib.crc32(data), hash_a, hash_c, hash_f, hash_g
assert all(h == check for h in hashes)
print(hashes)


if __name__ == '__main__':
        pass

Features

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Other featues:

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License

CRCx is licensed under Mozilla Public License.