Modern Node function for signing AWS REST HTTP request parameters with Version 2 Signature

sign.js

const crypto = require('crypto')

module.exports = (host, method, url, params, awsAccessKeyId, awsSecretAccessKey) => {
    const timestamp = (new Date()).toISOString()
    const newParams = `${params}&Timestamp=${timestamp}&AWSAccessKeyId=${awsAccessKeyId}`

    const sortedParams = newParams
        .split('&')
        .map(a => {
            const [k, v] = a.split('=')
            const param = `${k}=${encodeURIComponent(v)}`
            return { param, ascii: param.split('').map(g => g.charCodeAt()).join(',') }
        })
        .sort((a, b) => {
            return a.ascii.localeCompare(b.ascii, 'en', { numeric: true })
        })
        .map(a => a.param)
        .join('&')

    const toSign = `${method}\n${host}\n${url}\n${sortedParams}`
    const signature = crypto.createHmac('sha256', awsSecretAccessKey).update(toSign).digest('base64')
    return encodeURIComponent(signature)
}

usage.js

const signParams = require('./sign')

const AWS_ACCESS_KEY_ID = 'AKIAIOSFODNN7EXAMPLE'
const AWS_SECRET_ACCESS_KEY = '1234567890'

const params = 'SignatureVersion=2&SignatureMethod=HmacSHA256&Version=2009-04-15&Version=2009-04-15'

const signature = signParams('sdb.amazonaws.com', 'GET', '/onca/xml', params, AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY))

Correctly sorts and orders AWS REST HTTP parameters by byte value. Correctly escapes and URL-encodes parameter values.