import { NextFunction, Request, Response } from 'express' import { isActorDeleteActivityValid } from '@server/helpers/custom-validators/activitypub/actor' import { getAPId } from '@server/lib/activitypub/activity' import { wrapWithSpanAndContext } from '@server/lib/opentelemetry/tracing' import { ActivityDelete, ActivityPubSignature, HttpStatusCode } from '@shared/models' import { logger } from '../helpers/logger' import { isHTTPSignatureVerified, isJsonLDSignatureVerified, parseHTTPSignature } from '../helpers/peertube-crypto' import { ACCEPT_HEADERS, ACTIVITY_PUB, HTTP_SIGNATURE } from '../initializers/constants' import { getOrCreateAPActor, loadActorUrlOrGetFromWebfinger } from '../lib/activitypub/actors' 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.status(HttpStatusCode.NO_CONTENT_204).end() } logger.warn('Error in ActivityPub signature checker.', { err }) return res.fail({ status: HttpStatusCode.FORBIDDEN_403, message: 'ActivityPub signature could not be checked' }) } } 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) { return wrapWithSpanAndContext('peertube.activitypub.checkHTTPSignature', async () => { // 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.fail({ status: HttpStatusCode.FORBIDDEN_403, message: err.message }) return false } const keyId = parsed.keyId if (!keyId) { res.fail({ status: HttpStatusCode.FORBIDDEN_403, message: 'Invalid key ID', data: { keyId } }) 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 getOrCreateAPActor(actorUrl) const verified = isHTTPSignatureVerified(parsed, actor) if (verified !== true) { logger.warn('Signature from %s is invalid', actorUrl, { parsed }) res.fail({ status: HttpStatusCode.FORBIDDEN_403, message: 'Invalid signature', data: { actorUrl } }) return false } res.locals.signature = { actor } return true }) } async function checkJsonLDSignature (req: Request, res: Response) { return wrapWithSpanAndContext('peertube.activitypub.JSONLDSignature', async () => { const signatureObject: ActivityPubSignature = req.body.signature if (!signatureObject?.creator) { res.fail({ status: HttpStatusCode.FORBIDDEN_403, message: 'Object and creator signature do not match' }) return false } const [ creator ] = signatureObject.creator.split('#') logger.debug('Checking JsonLD signature of actor %s...', creator) const actor = await getOrCreateAPActor(creator) const verified = await isJsonLDSignatureVerified(actor, req.body) if (verified !== true) { logger.warn('Signature not verified.', req.body) res.fail({ status: HttpStatusCode.FORBIDDEN_403, message: 'Signature could not be verified' }) return false } res.locals.signature = { actor } return true }) }