@aws-crypto/crc32c

What is @aws-crypto/crc32c?

The @aws-crypto/crc32c package is designed for calculating CRC32C (Cyclic Redundancy Check) checksums. This is particularly useful for verifying the integrity of data, such as files or network packets, to ensure they have not been altered during transmission or storage. The CRC32C algorithm is known for its efficiency and error-detection capabilities, making it a popular choice for error-checking applications.

What are @aws-crypto/crc32c's main functionalities?

Calculate CRC32C checksum from a string

This feature allows you to calculate the CRC32C checksum of a given string. The input string is first converted to a Buffer, and then the `crc32c` function is used to calculate the checksum. The result is a number that represents the checksum, which can be converted to a hexadecimal string for easier reading or comparison.

"use strict";
const { crc32c } = require('@aws-crypto/crc32c');

const input = Buffer.from('Hello World');
const checksum = crc32c(input);
console.log(`CRC32C Checksum: ${checksum.toString(16)}`);

Calculate CRC32C checksum from a file

This feature demonstrates how to calculate the CRC32C checksum of a file. The file is read into a Buffer using Node.js's `fs.readFileSync` method, and then the `crc32c` function is applied to this Buffer to compute the checksum. This is useful for verifying the integrity of files.

"use strict";
const fs = require('fs');
const { crc32c } = require('@aws-crypto/crc32c');

const fileBuffer = fs.readFileSync('path/to/your/file.txt');
const checksum = crc32c(fileBuffer);
console.log(`CRC32C Checksum of the file: ${checksum.toString(16)}`);

Other packages similar to @aws-crypto/crc32c

fast-crc32c

The 'fast-crc32c' package is another Node.js module for computing CRC32C checksums. It offers similar functionality to '@aws-crypto/crc32c' but focuses on performance optimizations for Node.js environments. It uses native bindings to Google's Snappy project for faster computation, making it a good alternative for performance-critical applications.

buffer-crc32

While 'buffer-crc32' computes CRC32 checksums rather than CRC32C, it serves a similar purpose in verifying data integrity. The main difference lies in the algorithm used for the checksum calculation. 'buffer-crc32' might be preferred in scenarios where CRC32 is the required standard, but '@aws-crypto/crc32c' is specifically tailored for CRC32C computations.

README

@aws-crypto/crc32c

Pure JS implementation of CRC32-C https://en.wikipedia.org/wiki/Cyclic_redundancy_check

Usage

import { Crc32c } from '@aws-crypto/crc32c';

const crc32Digest = (new Crc32c).update(buffer).digest()

Test

npm test

Changelog

2.0.2 (2022-09-07)

Bug Fixes

• #337: update @aws-sdk/types (#373) (b26a811), closes #337
• docs: update README for packages/util (#382) (f3e650e)