Calculate CRC checksums, verify CRC checksum, predefined CRC configurations, custom CRC configurations
- Documentation: https://nicoretti.github.io/crc
- Source Code: https://github.com/Nicoretti/crc
For convenience various frequently used crc configurations ship with the library out of the box.
| CRC8 | CRC16 | CRC32 | CRC64 |
|---|---|---|---|
| CCITT | XMODEM | CRC32 | CRC64 |
| AUTOSAR | GSM | AUTOSAR | |
| SAEJ1850 | PROFIBUS | BZIP2 | |
| SAEJ1850_ZERO | MODBUS | POSIX | |
| BLUETOOTH | IBM-3740 | ||
| MAXIM-DOW | KERMIT |
If you find yourself in the position, where having a new configuration available out of the box would be desirable, feel free to create a PR or file an issue.
If you want to create a custom configuration, you should have the following information available:
🗒 Note:
This library currently only supports bit widths of full bytes 8, 16, 24, 32, ...
- width
- polynom
- init value
- final xor value
- reversed input
- reversed output
In case you only have a name of a specific crc configuration/algorithm and you are unsure what are the specific parameters of it, a look into this crc-catalogue might help.
pip install crcfrom crc import Calculator, Crc8
calculator = Calculator(Crc8.CCITT)from crc import Calculator, Configuration
config = Configuration(
width=8,
polynomial=0x07,
init_value=0x00,
final_xor_value=0x00,
reverse_input=False,
reverse_output=False,
)
calculator = Calculator(config)from crc import Calculator, Crc8
expected = 0xBC
data = bytes([0, 1, 2, 3, 4, 5])
calculator = Calculator(Crc8.CCITT)
assert expected == calculator.checksum(data)from crc import Calculator, Crc8
expected = 0xBC
data = bytes([0, 1, 2, 3, 4, 5])
calculator = Calculator(Crc8.CCITT, optimized=True)
assert expected == calculator.checksum(data)from crc import Calculator, Crc8
expected = 0xBC
data = bytes([0, 1, 2, 3, 4, 5])
calculator = Calculator(Crc8.CCITT)
assert calculator.verify(data, expected)from crc import Calculator, Crc8
expected = 0xBC
data = bytes([0, 1, 2, 3, 4, 5])
calculator = Calculator(Crc8.CCITT, optimized=True)
assert calculator.verify(data, expected)from crc import Crc8, Register
expected = 0xBC
data = bytes([0, 1, 2, 3, 4, 5])
register = Register(Crc8.CCITT)
register.init()
register.update(data)
assert expected == register.digest()from crc import Crc8, TableBasedRegister
expected = 0xBC
data = bytes([0, 1, 2, 3, 4, 5])
register = TableBasedRegister(Crc8.CCITT)
register.init()
register.update(data)
assert expected == register.digest()
