crc-full

---

Description

The crc-full module is used to calculate any kind of CRC setting parameters such as length, polynomial and others. It's completely written in typescript for node js.

How to use

Use is very simple. Just add the module to project.

Install dependencies:
The only one dependency is typescript compiler

npm install -g typescript

Import in node js

After typescript is installed, simple run:

npm install crc-full

Use in your project

First of all import the module in your project files, then create an instance of the class whith all parameters of the CRC algorithm you need. After the instance is create you can compute the CRC of your data passing an array of byte or simply a buffer object.

For typescript use:

import {CRC} from 'crc-full'
...
let crc =  new CRC("CRC16", 16, 0x8005, 0x0000, 0x0000, false, false);
crc.compute([0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64, 0x21]);
let computed_crc = crc.compute(Buffer.from("Hello world!","ascii"))

For javascript use:

const CRC = require('crc-full').CRC;
var crc = new CRC("CRC16", 16, 0x8005, 0x0000, 0x0000, false, false);
crc.compute([0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64, 0x21]);
var computed_crc = crc.compute(Buffer.from("Hello world!", "ascii"))

Where the parameters in the constructor are:

• Length: the Length of CRC in bit (8,16,32)
• Name: friendly name for the configuration
• Polinomial: the polinomial used to compute CRC
• InitialValue: initial value of CRC
• FinalXorValue: final value of CRC
• InputReflected: boolen that indicate if need to reflect input
• OutputReflected: boolen that indicate if need to reflect input

Presets

Invoking the static getter defaults is possible to use the internal preconfigurated CRC algorithms. An array of instantiated object is returned back

The algorithms are:

Length	Name	Polinomial	Initial value	Final value	Input reflected	Output reflected
8	CRC8	0x07	0x00	0x00	false	false)
8	CRC8_SAE_J1850	0x1D	0xFF	0xFF	false	false)
8	CRC8_SAE_J1850_ZERO	0x1D	0x00	0x00	false	false)
8	CRC8_8H2F	0x2F	0xFF	0xFF	false	false)
8	CRC8_CDMA2000	0x9B	0xFF	0x00	false	false)
8	CRC8_DARC	0x39	0x00	0x00	true	true)
8	CRC8_DVB_S2	0xD5	0x00	0x00	false	false)
8	CRC8_EBU	0x1D	0xFF	0x00	true	true)
8	CRC8_ICODE	0x1D	0xFD	0x00	false	false)
8	CRC8_ITU	0x07	0x00	0x55	false	false
8	CRC8_MAXIM	0x31	0x00	0x00	true	true
8	CRC8_ROHC	0x07	0xFF	0x00	true	true
8	CRC8_WCDMA	0x9B	0x00	0x00	true	true
16	CRC16_CCIT_ZERO	0x1021	0x0000	0x0000	false	false
16	CRC16_ARC	0x8005	0x0000	0x0000	true	true
16	CRC16_AUG_CCITT	0x1021	0x1D0F	0x0000	false	false
16	CRC16_BUYPASS	0x8005	0x0000	0x0000	false	false
16	CRC16_CCITT_FALSE	0x1021	0xFFFF	0x0000	false	false
16	CRC16_CDMA2000	0xC867	0xFFFF	0x0000	false	false
16	CRC16_DDS_110	0x8005	0x800D	0x0000	false	false
16	CRC16_DECT_R	0x0589	0x0000	0x0001	false	false
16	CRC16_DECT_X	0x0589	0x0000	0x0000	false	false
16	CRC16_DNP	0x3D65	0x0000	0xFFFF	true	true
16	CRC16_EN_13757	0x3D65	0x0000	0xFFFF	false	false
16	CRC16_GENIBUS	0x1021	0xFFFF	0xFFFF	false	false
16	CRC16_MAXIM	0x8005	0x0000	0xFFFF	true	true
16	CRC16_MCRF4XX	0x1021	0xFFFF	0x0000	true	true
16	CRC16_RIELLO	0x1021	0xB2AA	0x0000	true	true
16	CRC16_T10_DIF	0x8BB7	0x0000	0x0000	false	false
16	CRC16_TELEDISK	0xA097	0x0000	0x0000	false	false
16	CRC16_TMS37157	0x1021	0x89EC	0x0000	true	true
16	CRC16_USB	0x8005	0xFFFF	0xFFFF	true	true
16	CRC16_A	0x1021	0xC6C6	0x0000	true	true
16	CRC16_KERMIT	0x1021	0x0000	0x0000	true	true
16	CRC16_MODBUS	0x8005	0xFFFF	0x0000	true	true
16	CRC16_X_25	0x1021	0xFFFF	0xFFFF	true	true
16	CRC16_XMODEM	0x1021	0x0000	0x0000	false	false
32	CRC32	0x04C11DB7	0xFFFFFFFF	0xFFFFFFFF	true	true
32	CRC32_BZIP2	0x04C11DB7	0xFFFFFFFF	0xFFFFFFFF	false	false
32	CRC32_C	0x1EDC6F41	0xFFFFFFFF	0xFFFFFFFF	true	true
32	CRC32_D	0xA833982B	0xFFFFFFFF	0xFFFFFFFF	true	true
32	CRC32_MPEG2	0x04C11DB7	0xFFFFFFFF	0x00000000	false	false
32	CRC32_POSIX	0x04C11DB7	0x00000000	0xFFFFFFFF	false	false
32	CRC32_Q	0x814141AB	0x00000000	0x00000000	false	false
32	CRC32_JAMCRC	0x04C11DB7	0xFFFFFFFF	0x00000000	true	true
32	CRC32_XFER	0x000000AF	0x00000000	0x00000000	false	false

Is possible to use one of above CRC preset using the method default(name) where parameter name is the name of chosen preset.

Typescript users can use:

import {CRC} from 'crc-full'
let crc = CRC.default("CRC16_CCIT_ZERO");
let computed_crc = crc.compute(Buffer.from("Hello world!","ascii"))

Typescript users can use:

const CRC = require('crc-full').CRC;
var crc = CRC.default("CRC16_CCIT_ZERO");
var computed_crc = crc.compute(Buffer.from("Hello world!","ascii"))

Advanced

The module also support advanced methods to calculate CRC tables and export them as byte arrays:

...
crc.makeCrcTable();
crc.makeCrcTableReversed();
var table = crc.table;
...

Notes

The method compute take a byte array (or Buffer) as input and returns a number.
If you need to convert a string you have to pass it as a byte array.
If you need to read the CRC result in hex format string use .toString(16)