Refactor auth flow

Reimplement some node-oauth2-server methods to remove hacky code needed by our external
login workflow

server/lib/auth/oauth.ts

@@ -0,0 +1,180 @@
+import * as express from 'express'
+import {
+  InvalidClientError,
+  InvalidGrantError,
+  InvalidRequestError,
+  Request,
+  Response,
+  UnauthorizedClientError,
+  UnsupportedGrantTypeError
+} from 'oauth2-server'
+import { randomBytesPromise, sha1 } from '@server/helpers/core-utils'
+import { MOAuthClient } from '@server/types/models'
+import { OAUTH_LIFETIME } from '../../initializers/constants'
+import { BypassLogin, getClient, getRefreshToken, getUser, revokeToken, saveToken } from './oauth-model'
+
+/**
+ *
+ * Reimplement some functions of OAuth2Server to inject external auth methods
+ *
+ */
+
+const oAuthServer = new (require('oauth2-server'))({
+  accessTokenLifetime: OAUTH_LIFETIME.ACCESS_TOKEN,
+  refreshTokenLifetime: OAUTH_LIFETIME.REFRESH_TOKEN,
+
+  // See https://github.com/oauthjs/node-oauth2-server/wiki/Model-specification for the model specifications
+  model: require('./oauth-model')
+})
+
+// ---------------------------------------------------------------------------
+
+async function handleOAuthToken (req: express.Request, options: { refreshTokenAuthName?: string, bypassLogin?: BypassLogin }) {
+  const request = new Request(req)
+  const { refreshTokenAuthName, bypassLogin } = options
+
+  if (request.method !== 'POST') {
+    throw new InvalidRequestError('Invalid request: method must be POST')
+  }
+
+  if (!request.is([ 'application/x-www-form-urlencoded' ])) {
+    throw new InvalidRequestError('Invalid request: content must be application/x-www-form-urlencoded')
+  }
+
+  const clientId = request.body.client_id
+  const clientSecret = request.body.client_secret
+
+  if (!clientId || !clientSecret) {
+    throw new InvalidClientError('Invalid client: cannot retrieve client credentials')
+  }
+
+  const client = await getClient(clientId, clientSecret)
+  if (!client) {
+    throw new InvalidClientError('Invalid client: client is invalid')
+  }
+
+  const grantType = request.body.grant_type
+  if (!grantType) {
+    throw new InvalidRequestError('Missing parameter: `grant_type`')
+  }
+
+  if (![ 'password', 'refresh_token' ].includes(grantType)) {
+    throw new UnsupportedGrantTypeError('Unsupported grant type: `grant_type` is invalid')
+  }
+
+  if (!client.grants.includes(grantType)) {
+    throw new UnauthorizedClientError('Unauthorized client: `grant_type` is invalid')
+  }
+
+  if (grantType === 'password') {
+    return handlePasswordGrant({
+      request,
+      client,
+      bypassLogin
+    })
+  }
+
+  return handleRefreshGrant({
+    request,
+    client,
+    refreshTokenAuthName
+  })
+}
+
+async function handleOAuthAuthenticate (
+  req: express.Request,
+  res: express.Response,
+  authenticateInQuery = false
+) {
+  const options = authenticateInQuery
+    ? { allowBearerTokensInQueryString: true }
+    : {}
+
+  return oAuthServer.authenticate(new Request(req), new Response(res), options)
+}
+
+export {
+  handleOAuthToken,
+  handleOAuthAuthenticate
+}
+
+// ---------------------------------------------------------------------------
+
+async function handlePasswordGrant (options: {
+  request: Request
+  client: MOAuthClient
+  bypassLogin?: BypassLogin
+}) {
+  const { request, client, bypassLogin } = options
+
+  if (!request.body.username) {
+    throw new InvalidRequestError('Missing parameter: `username`')
+  }
+
+  if (!bypassLogin && !request.body.password) {
+    throw new InvalidRequestError('Missing parameter: `password`')
+  }
+
+  const user = await getUser(request.body.username, request.body.password, bypassLogin)
+  if (!user) throw new InvalidGrantError('Invalid grant: user credentials are invalid')
+
+  const token = await buildToken()
+
+  return saveToken(token, client, user, { bypassLogin })
+}
+
+async function handleRefreshGrant (options: {
+  request: Request
+  client: MOAuthClient
+  refreshTokenAuthName: string
+}) {
+  const { request, client, refreshTokenAuthName } = options
+
+  if (!request.body.refresh_token) {
+    throw new InvalidRequestError('Missing parameter: `refresh_token`')
+  }
+
+  const refreshToken = await getRefreshToken(request.body.refresh_token)
+
+  if (!refreshToken) {
+    throw new InvalidGrantError('Invalid grant: refresh token is invalid')
+  }
+
+  if (refreshToken.client.id !== client.id) {
+    throw new InvalidGrantError('Invalid grant: refresh token is invalid')
+  }
+
+  if (refreshToken.refreshTokenExpiresAt && refreshToken.refreshTokenExpiresAt < new Date()) {
+    throw new InvalidGrantError('Invalid grant: refresh token has expired')
+  }
+
+  await revokeToken({ refreshToken: refreshToken.refreshToken })
+
+  const token = await buildToken()
+
+  return saveToken(token, client, refreshToken.user, { refreshTokenAuthName })
+}
+
+function generateRandomToken () {
+  return randomBytesPromise(256)
+    .then(buffer => sha1(buffer))
+}
+
+function getTokenExpiresAt (type: 'access' | 'refresh') {
+  const lifetime = type === 'access'
+    ? OAUTH_LIFETIME.ACCESS_TOKEN
+    : OAUTH_LIFETIME.REFRESH_TOKEN
+
+  return new Date(Date.now() + lifetime * 1000)
+}
+
+async function buildToken () {
+  const [ accessToken, refreshToken ] = await Promise.all([ generateRandomToken(), generateRandomToken() ])
+
+  return {
+    accessToken,
+    refreshToken,
+    accessTokenExpiresAt: getTokenExpiresAt('access'),
+    refreshTokenExpiresAt: getTokenExpiresAt('refresh')
+  }
+}