pburggraf / crc

Cyclic redundancy checker class

CRC

This is an implementation of the CRC RevEng Catalogue in PHP 7.x

How to use

<?php

// Autoloading via Composer
require __DIR__ . '/vendor/autoload.php';

$crc8 = new \PBurggraf\CRC\CRC8\CRC8();
var_dump(dechex($crc8->calculate('123456789'))); // string(2) "f4"

$crc16AugCcitt = new \PBurggraf\CRC\CRC16\AugCcitt();
var_dump(dechex($crc16AugCcitt->calculate('123456789'))); // string(4) "e5cc"

$crc24 = new \PBurggraf\CRC\CRC24\CRC24();
var_dump(dechex($crc24->calculate('123456789'))); // string(6) "21cf02"

$crc32 = new \PBurggraf\CRC\CRC32\CRC32();
var_dump(dechex($crc32->calculate('123456789'))); // string(8) "cbf43926"

Test

This project uses phpunit to test the validation of crc calculations.

Currently implemented

8bit CRC

AUTOSAR, BLUETOOTH, CDMA2000, DARC, DVB-S2, GSM-A, GSM-B, I-432-1 (ITU), I-CODE, LTE, MAXIM-DOW (MAXIM, DOW-CRC), MIFARE-MAD, NRSC-5, OPENSAFETY, ROHC, SAE-J1850, SMBUS (CRC-8), TECH-3250 (AES, EBU)

16bit CRC

ARC (CRC-16, LHA, CRC-IBM), CDMA2000, CMS, DDS-110, DECT-R (R-CRC-16), DECT-X (X-CRC-16), DNP, EN-13757, GENIBUS (DARC, EPC, EPC-C1G2, I-CODE), GSM, IBM-3740 (AUTOSAR, CCITT-FALSE), IBM-SDLC (ISO-HDLC, ISO-IEC-14443-3-B, X-25, CRC-B), ISO-IEC-14443-3-A (CRC-A), KERMIT (CCITT, CCITT-TRUE, V-41-LSB, KERMIT), LJ1200, MAXIM-DOW (MAXIM), MCRF4XX, MODBUS, NRSC-5, OPENSAFETY-A OPENSAFETY-B, PROFIBUS (IEC-61158-2), RIELLO, SPI-FUJITSU (AUG-CCITT), T10-DIF, TELEDISK, TMS37157, UMTS (BUYPASS, VERIFONE), USB, XMODEM (ACORN, LTE, V-41-MSB, ZMODEM)

24bit CRC

BLE, FLEXRAY-A, FLEXRAY-B, INTERLAKEN, LTE-A, LTE-B, OPENPGP (CRC-24)

32bit CRC

AIXM (CRC-32Q), AUTOSAR, BASE91-D (CRC-32D), BZIP2 (AAL5, DECT-B, B-CRC-32), CD-ROM-EDC, CKSUM (POSIX), ISCSI (BASE91-C, CASTAGNOLI, INTERLAKEN, CRC-32C), ISO-HDLC (CRC-32, ADCCP, V-42, XZ, PKZIP), JAMCRC, MPEG-2, XFER

crc's Issues

Integrating PHP-CS-Fixer coding style tool

See this issue.

Integrating phpstan/phpstan during Travis CI build

See this issue.

Package gets identified as phpstan-extension

I am using phpstan/extension-installer to autoload all phpstan extensions. It tries to find a phpstan extension file in this package:

./vendor/bin/phpstan analyse
Note: Using configuration file /path/to/project/phpstan.neon.
Config file /path/to/project/vendor/pburggraf/crc/extension.neon does not exist or isn't readable

According to https://github.com/phpstan/extension-installer#instructions-for-extension-developers I think, you should remove the following part from your composer.json:

 "extra": {
    "phpstan": {
      "includes": [
        "extension.neon"
      ]
    }
  }

Multiple performance issues in the library

There is some serious performance issues in the library

1. The lookup table is generated in the constructor, this slows down the instantiation of a class, the constructor should not have heavy logic and it would be much better to use dependency injection and pass the lookup table as an argument.
2. The lookup table is never used (!), there is a table generation for literally nothing as we don't rely on the lookup table at all to generate CRCs

Those issues make the library way slower than it should be, for nothing. Either the lookup table should be removed from the constructor, either it should be used later on (but I dislike the idea of generating a table to then use it, it doesn't make sense) or better: we can inject the lookup table to speed up calculation, if not it will rely on the current implementation.

Ho i can compute crc by hex?

Ho i can compute crc by hex?

Like this https://crccalc.com/?crc=011A9461005900&method=crc8&datatype=hex

(Radio button hex checked)

@pburggraf ?