import { NextFunction, Request, Response } from 'express' import { 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' import { loadActorUrlOrGetFromWebfinger } from '../helpers/webfinger' 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 = bodyActor && bodyActor.id ? bodyActor.id : bodyActor if (bodyActorId && bodyActorId !== actor.url) { const jsonLDSignatureChecked = await checkJsonLDSignature(req, res) if (jsonLDSignatureChecked !== true) return } return next() } catch (err) { logger.error('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.indexOf(accepted) === -1) { // 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: mastodon does not include the Signature scheme const sig = req.headers[HTTP_SIGNATURE.HEADER_NAME] as string if (sig && sig.startsWith('Signature ') === false) req.headers[HTTP_SIGNATURE.HEADER_NAME] = 'Signature ' + sig const parsed = parseHTTPSignature(req) 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) { res.sendStatus(403) return false } res.locals.signature = { actor } return true }