crc

Module for calculating Cyclic Redundancy Check (CRC).

Features

Pure JavaScript implementation, no dependencies.
Provides CRC Tables for optimized calculations.
Provides support for the following CRC algorithms:
- CRC1 new crc.CRC1 or crc.crc1(…)
- CRC8 new crc.CRC8 or crc.crc8(…)
- CRC8 1-Wire new crc.CRC81Wire or crc.crc81wire(…)
- CRC16 new crc.CRC16 or crc.crc16(…)
- CRC16 CCITT new crc.CRC16CCITT or crc.crc16ccitt(…)
- CRC16 Modbus new crc.CRC16Modbus or crc.crc16modbus(…)
- CRC24 new crc.CRC24 or crc.crc24(…)
- CRC32 new crc.CRC32 or crc.crc32(…)

Installation

npm install crc

Running tests

$ npm install
$ npm test

Usage Example

Calculate a CRC32:

var crc = require('crc');

crc.crc32('hello');
# => "3610a686"

Calculate a CRC32 of a file:

crc.crc32(fs.readFileAsync('README.md', 'utf8'));
# => "127ad531"

Incrementally calculate a CRC32:

crc32 = new crc.CRC32()
crc32.update('one')
crc32.update('two')
crc32.update('three')
crc32.hexdigest()
# => "09e1c092"

Directly access the checksum:

crc32.checksum()
# => 165789842

Upgrading

Older version 0.3.0 was unfortunately ported from a not so reliable source and results were not matching other libraries. If you are using 3.x please continue using it.

crc8(String)             #=> Number
crcArc(String)           #=> Number
crcModbusString(string)  #=> Number
crcModbusHex(Number)     #=> Number
crc16(String)            #=> Number
crc16CCITT(String)       #=> Number
fcs16(String)            #=> Number
crc32(String)            #=> Number
hex8(Number)             #=> String
hex16(Number)            #=> String
hex32(Number)            #=> String

Thanks

This module is a direct port from Ruby's Digest CRC module. Which is in turn based on pycrc library which is able to generate C source-code for all of the CRC algorithms, including their CRC Tables.

License

The MIT License (MIT)

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.

hashrock/node-crc