PeerTube/server/middlewares/activitypub.ts

131 lines
4.0 KiB
TypeScript

import { NextFunction, Request, Response } from 'express'
import { ActivityDelete, ActivityPubSignature } from '../../shared'
import { logger } from '../helpers/logger'
import { isHTTPSignatureVerified, isJsonLDSignatureVerified, parseHTTPSignature } from '../helpers/peertube-crypto'
import { ACCEPT_HEADERS, ACTIVITY_PUB, HTTP_SIGNATURE } from '../initializers/constants'
import { getOrCreateActorAndServerAndModel } from '../lib/activitypub/actor'
import { loadActorUrlOrGetFromWebfinger } from '../helpers/webfinger'
import { isActorDeleteActivityValid } from '@server/helpers/custom-validators/activitypub/actor'
import { getAPId } from '@server/helpers/activitypub'
async function checkSignature (req: Request, res: Response, next: NextFunction) {
try {
const httpSignatureChecked = await checkHttpSignature(req, res)
if (httpSignatureChecked !== true) return
const actor = res.locals.signature.actor
// Forwarded activity
const bodyActor = req.body.actor
const bodyActorId = getAPId(bodyActor)
if (bodyActorId && bodyActorId !== actor.url) {
const jsonLDSignatureChecked = await checkJsonLDSignature(req, res)
if (jsonLDSignatureChecked !== true) return
}
return next()
} catch (err) {
const activity: ActivityDelete = req.body
if (isActorDeleteActivityValid(activity) && activity.object === activity.actor) {
logger.debug('Handling signature error on actor delete activity', { err })
return res.sendStatus(204)
}
logger.warn('Error in ActivityPub signature checker.', { err })
return res.sendStatus(403)
}
}
function executeIfActivityPub (req: Request, res: Response, next: NextFunction) {
const accepted = req.accepts(ACCEPT_HEADERS)
if (accepted === false || ACTIVITY_PUB.POTENTIAL_ACCEPT_HEADERS.includes(accepted) === false) {
// Bypass this route
return next('route')
}
logger.debug('ActivityPub request for %s.', req.url)
return next()
}
// ---------------------------------------------------------------------------
export {
checkSignature,
executeIfActivityPub,
checkHttpSignature
}
// ---------------------------------------------------------------------------
async function checkHttpSignature (req: Request, res: Response) {
// FIXME: compatibility with http-signature < v1.3
const sig = req.headers[HTTP_SIGNATURE.HEADER_NAME] as string
if (sig && sig.startsWith('Signature ') === true) req.headers[HTTP_SIGNATURE.HEADER_NAME] = sig.replace(/^Signature /, '')
let parsed: any
try {
parsed = parseHTTPSignature(req, HTTP_SIGNATURE.CLOCK_SKEW_SECONDS)
} catch (err) {
logger.warn('Invalid signature because of exception in signature parser', { reqBody: req.body, err })
res.status(403).json({ error: err.message })
return false
}
const keyId = parsed.keyId
if (!keyId) {
res.sendStatus(403)
return false
}
logger.debug('Checking HTTP signature of actor %s...', keyId)
let [ actorUrl ] = keyId.split('#')
if (actorUrl.startsWith('acct:')) {
actorUrl = await loadActorUrlOrGetFromWebfinger(actorUrl.replace(/^acct:/, ''))
}
const actor = await getOrCreateActorAndServerAndModel(actorUrl)
const verified = isHTTPSignatureVerified(parsed, actor)
if (verified !== true) {
logger.warn('Signature from %s is invalid', actorUrl, { parsed })
res.sendStatus(403)
return false
}
res.locals.signature = { actor }
return true
}
async function checkJsonLDSignature (req: Request, res: Response) {
const signatureObject: ActivityPubSignature = req.body.signature
if (!signatureObject || !signatureObject.creator) {
res.sendStatus(403)
return false
}
const [ creator ] = signatureObject.creator.split('#')
logger.debug('Checking JsonLD signature of actor %s...', creator)
const actor = await getOrCreateActorAndServerAndModel(creator)
const verified = await isJsonLDSignatureVerified(actor, req.body)
if (verified !== true) {
logger.warn('Signature not verified.', req.body)
res.sendStatus(403)
return false
}
res.locals.signature = { actor }
return true
}