trusona/trusona-server-sdk-js

const HmacSignatureGenerator = require('./security/HmacSignatureGenerator')
const ResponseHmacMessage = require('./security/ResponseHmacMessage')
const RequestHmacMessage = require('./security/RequestHmacMessage')
const TrusonaError = require('../../resources/error/TrusonaError')
const camelcase = require('./camelcase')

class RequestHelper {

  constructor(token, secret, endpoint) {
    this.token = token
    this.secret = secret
    this.baseUrl = endpoint
  }

  getSignedRequest(options) {
    options.baseUrl = this.baseUrl
    options.headers = this.getHeaders(options)
    options.json = false
    options.body = JSON.stringify(options.body)

    let originalTransform = options.transform
    const signatureGenerator = new HmacSignatureGenerator()

    if (!originalTransform) {
      originalTransform = (body, response, resolveWithFullResponse) => {
        return body
      }
    }

    options.transform = (body, response, resolveWithFullResponse) => {

      if(response.statusCode.toString().startsWith('2')) {
        const responseHmacMessage = new ResponseHmacMessage(response)
        const signature = signatureGenerator.getSignature(responseHmacMessage, this.secret)

        if (response.headers['x-signature'] === signature) {
          const parsedBody = body ? JSON.parse(body) : body
          return originalTransform(camelcase(parsedBody), response, resolveWithFullResponse)
        } else {
          throw new TrusonaError('The response signature failed validation')
        }
      }
    }

    const requestHmacMessage = new RequestHmacMessage(options)
    const signature = signatureGenerator.getSignature(requestHmacMessage, this.secret)

    options.headers['authorization'] = `TRUSONA ${this.token}:${signature}`
    return options
  }

  getHeaders(options) {
    const date = new Date().toUTCString()
    let headers = {
      'user-agent': 'TrusonaServerSdk/1.0',
      'x-date' : date,
      'date' : date
    }

    if (options.body) {
      headers['content-type'] = 'application/json'
      headers['accept'] = 'application/json'
    }
    return headers
  }
}

module.exports = RequestHelper