Knot HTTP Requests Signer

Library used to sign the HTTP request as defined in https://tools.ietf.org/html/draft-cavage-http-signatures-12.
More info on why we use it can be found here.

Installation

This project is written in TypeScript using Node.js 12 and targeting es2017.
It MAY work for older versions of Node.js.

Install using npm:
``



npm install @knotcity/http-request-signer





Usage



You have a client and server example in the

example/

 folder.

Import the module in the same way as you do normally.



// JavaScript

const hrs = require('@knotcity/http-request-signer');

// TypeScript

import hrs = require('@knotcity/http-request-signer');





Generating a key



You can use the crypto module from Node.js to generate a key pair or the utility function in the package to generate an ec

secp521r1

 curve.



const keyPair = hrs.generateECKeyPair();

// Public key

keyPair.publicKey;

// Private key

keyPair.privateKey;





Signing a request



To sign a request you need to add the

Authorization header with the value given by the generateAuthorization

 function.



import http = require('http');



// Make a request using node's HTTP module, but you can also use other modules like axios

const req = http.request(...);



// Fetch the private key from somewhere safe

const privKey = "...";



// Generate the signature

const auth = hrs.generateAuthorization({

    headers: req.getHeaders(),

    method: req.method,

    path: req.path

}, {

    headers: ['date', '(request-target)', 'content-length'], // List of header to use in the signature

    privateKey: privKey, // Private key

    hash: 'sha256', // Hash to use

    algorithm: 'ecdsa', // Algorithm used for the key

    keyId: 'keyn1' // The key identifier (this is defined by you, to allow to find the public key matching the private key)

});



// Add signature to request

req.setHeader('authorization', auth);





Verifying a signature



The verification process is similar to the signature process as we collect the same info, but using the public key instead of the private key (as the server does not know the private key).



try

{

    // Extract all components of the Authorization header

    const components = hrs.parseAuthorizationHeader(req.headers.authorization);

    

    // Here you would get the keyId from the components and fetch the matching public key

    const pubKey = "...";



    const valid = verifyAuthorization(components, {

            headers: req.headers,

            method: req.method || '',

            path: req.url || ''

        }, pubKey);

}

catch(err)

{

    // Throws if the header cannot be parsed

}