server/middlewares/activitypub.ts

   1 import { eachSeries } from 'async'
   2 import { NextFunction, Request, RequestHandler, Response } from 'express'
   3 import { ActivityPubSignature } from '../../shared'
   4 import { isSignatureVerified, logger } from '../helpers'
   5 import { ACCEPT_HEADERS, ACTIVITY_PUB } from '../initializers'
   6 import { getOrCreateActorAndServerAndModel } from '../lib/activitypub'
   7 import { ActorModel } from '../models/activitypub/actor'
   8
   9 async function checkSignature (req: Request, res: Response, next: NextFunction) {
  10   const signatureObject: ActivityPubSignature = req.body.signature
  11
  12   logger.debug('Checking signature of actor %s...', signatureObject.creator)
  13
  14   let actor: ActorModel
  15   try {
  16     actor = await getOrCreateActorAndServerAndModel(signatureObject.creator)
  17   } catch (err) {
  18     logger.error('Cannot create remote actor and check signature.', err)
  19     return res.sendStatus(403)
  20   }
  21
  22   const verified = await isSignatureVerified(actor, req.body)
  23   if (verified === false) return res.sendStatus(403)
  24
  25   res.locals.signature = {
  26     actor
  27   }
  28
  29   return next()
  30 }
  31
  32 function executeIfActivityPub (fun: RequestHandler | RequestHandler[]) {
  33   return (req: Request, res: Response, next: NextFunction) => {
  34     const accepted = req.accepts(ACCEPT_HEADERS)
  35     if (accepted === false || ACTIVITY_PUB.POTENTIAL_ACCEPT_HEADERS.indexOf(accepted) === -1) {
  36       return next()
  37     }
  38
  39     logger.debug('ActivityPub request for %s.', req.url)
  40
  41     if (Array.isArray(fun) === true) {
  42       return eachSeries(fun as RequestHandler[], (f, cb) => {
  43         f(req, res, cb)
  44       }, next)
  45     }
  46
  47     return (fun as RequestHandler)(req, res, next)
  48   }
  49 }
  50
  51 // ---------------------------------------------------------------------------
  52
  53 export {
  54   checkSignature,
  55   executeIfActivityPub
  56 }