@tufjs/canonical-json

What is @tufjs/canonical-json?

The @tufjs/canonical-json npm package is designed for creating JSON strings in a canonical format. This is particularly useful in scenarios where consistent byte representations of JSON objects are necessary, such as cryptographic operations or when comparing JSON data structures without regard to non-significant differences like whitespace or key ordering.

What are @tufjs/canonical-json's main functionalities?

Canonicalization of JSON objects

This feature allows the conversion of JavaScript objects into a canonical JSON string format, ensuring consistent ordering of object keys and formatting.

const canonicalJson = require('@tufjs/canonical-json');
const obj = { b: 1, a: 2 };
const canonicalObjStr = canonicalJson.stringify(obj);
// canonicalObjStr will be '{"a":2,"b":1}'

Other packages similar to @tufjs/canonical-json

json-stable-stringify

Similar to @tufjs/canonical-json, json-stable-stringify offers functionality for producing deterministic JSON strings by sorting the keys. It allows for custom comparison functions, which provides flexibility in how the canonicalization is performed compared to @tufjs/canonical-json.

canonical-json

This package also aims to provide a way to generate canonical JSON strings. It's similar in purpose to @tufjs/canonical-json but is a different implementation. The choice between the two might come down to specific project dependencies or personal preference for one API over the other.

README

@tufjs/canonical-json

JSON canonicalization compliant with the OLPC Canonical JSON specification.

Why

If you're looking for RFC 8785 compliant JSON canonicalization there are any number of libraries to choose from. You should only select this library if you know that you specifically need support for the OLPC-style of canonicalization.

One reason you might chose OLPC compliance is for interoperability with The Update Framework which specifically calls out OLPC as the canonicalization standard for computing signatures over TUF metadata.

The canonicalized strings generated by this library are compatible with those generated by the Python-based securesystemslib library and the Go-based go-securesystemslib library.

Installation

npm install @tufjs/canonical-json

Usage

const json = require('@tufjs/canonical-json')

const obj = {
  bool: true,
  num: 42,
  ary: [1, 2, 3],
  str: "foo\\bar"
}

console.log(json.canonicalize(obj))
// output: {"ary":[1,2,3],"bool":true,"num":42,"str":"foo\\bar"}