Refactor auth flow

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

4 files changed, 696 insertions, 0 deletions

diff --git a/server/lib/auth/external-auth.ts b/server/lib/auth/external-auth.ts
new file mode 100644
index 000000000..80f5064b6
--- /dev/null
+++ b/server/lib/auth/external-auth.ts
@@ -0,0 +1,219 @@
+
+import { isUserDisplayNameValid, isUserRoleValid, isUserUsernameValid } from '@server/helpers/custom-validators/users'
+import { logger } from '@server/helpers/logger'
+import { generateRandomString } from '@server/helpers/utils'
+import { PLUGIN_EXTERNAL_AUTH_TOKEN_LIFETIME } from '@server/initializers/constants'
+import { PluginManager } from '@server/lib/plugins/plugin-manager'
+import { OAuthTokenModel } from '@server/models/oauth/oauth-token'
+import {
+  RegisterServerAuthenticatedResult,
+  RegisterServerAuthPassOptions,
+  RegisterServerExternalAuthenticatedResult
+} from '@server/types/plugins/register-server-auth.model'
+import { UserRole } from '@shared/models'
+
+// Token is the key, expiration date is the value
+const authBypassTokens = new Map<string, {
+  expires: Date
+  user: {
+    username: string
+    email: string
+    displayName: string
+    role: UserRole
+  }
+  authName: string
+  npmName: string
+}>()
+
+async function onExternalUserAuthenticated (options: {
+  npmName: string
+  authName: string
+  authResult: RegisterServerExternalAuthenticatedResult
+}) {
+  const { npmName, authName, authResult } = options
+
+  if (!authResult.req || !authResult.res) {
+    logger.error('Cannot authenticate external user for auth %s of plugin %s: no req or res are provided.', authName, npmName)
+    return
+  }
+
+  const { res } = authResult
+
+  if (!isAuthResultValid(npmName, authName, authResult)) {
+    res.redirect('/login?externalAuthError=true')
+    return
+  }
+
+  logger.info('Generating auth bypass token for %s in auth %s of plugin %s.', authResult.username, authName, npmName)
+
+  const bypassToken = await generateRandomString(32)
+
+  const expires = new Date()
+  expires.setTime(expires.getTime() + PLUGIN_EXTERNAL_AUTH_TOKEN_LIFETIME)
+
+  const user = buildUserResult(authResult)
+  authBypassTokens.set(bypassToken, {
+    expires,
+    user,
+    npmName,
+    authName
+  })
+
+  // Cleanup expired tokens
+  const now = new Date()
+  for (const [ key, value ] of authBypassTokens) {
+    if (value.expires.getTime() < now.getTime()) {
+      authBypassTokens.delete(key)
+    }
+  }
+
+  res.redirect(`/login?externalAuthToken=${bypassToken}&username=${user.username}`)
+}
+
+async function getAuthNameFromRefreshGrant (refreshToken?: string) {
+  if (!refreshToken) return undefined
+
+  const tokenModel = await OAuthTokenModel.loadByRefreshToken(refreshToken)
+
+  return tokenModel?.authName
+}
+
+async function getBypassFromPasswordGrant (username: string, password: string) {
+  const plugins = PluginManager.Instance.getIdAndPassAuths()
+  const pluginAuths: { npmName?: string, registerAuthOptions: RegisterServerAuthPassOptions }[] = []
+
+  for (const plugin of plugins) {
+    const auths = plugin.idAndPassAuths
+
+    for (const auth of auths) {
+      pluginAuths.push({
+        npmName: plugin.npmName,
+        registerAuthOptions: auth
+      })
+    }
+  }
+
+  pluginAuths.sort((a, b) => {
+    const aWeight = a.registerAuthOptions.getWeight()
+    const bWeight = b.registerAuthOptions.getWeight()
+
+    // DESC weight order
+    if (aWeight === bWeight) return 0
+    if (aWeight < bWeight) return 1
+    return -1
+  })
+
+  const loginOptions = {
+    id: username,
+    password
+  }
+
+  for (const pluginAuth of pluginAuths) {
+    const authOptions = pluginAuth.registerAuthOptions
+    const authName = authOptions.authName
+    const npmName = pluginAuth.npmName
+
+    logger.debug(
+      'Using auth method %s of plugin %s to login %s with weight %d.',
+      authName, npmName, loginOptions.id, authOptions.getWeight()
+    )
+
+    try {
+      const loginResult = await authOptions.login(loginOptions)
+
+      if (!loginResult) continue
+      if (!isAuthResultValid(pluginAuth.npmName, authOptions.authName, loginResult)) continue
+
+      logger.info(
+        'Login success with auth method %s of plugin %s for %s.',
+        authName, npmName, loginOptions.id
+      )
+
+      return {
+        bypass: true,
+        pluginName: pluginAuth.npmName,
+        authName: authOptions.authName,
+        user: buildUserResult(loginResult)
+      }
+    } catch (err) {
+      logger.error('Error in auth method %s of plugin %s', authOptions.authName, pluginAuth.npmName, { err })
+    }
+  }
+
+  return undefined
+}
+
+function getBypassFromExternalAuth (username: string, externalAuthToken: string) {
+  const obj = authBypassTokens.get(externalAuthToken)
+  if (!obj) throw new Error('Cannot authenticate user with unknown bypass token')
+
+  const { expires, user, authName, npmName } = obj
+
+  const now = new Date()
+  if (now.getTime() > expires.getTime()) {
+    throw new Error('Cannot authenticate user with an expired external auth token')
+  }
+
+  if (user.username !== username) {
+    throw new Error(`Cannot authenticate user ${user.username} with invalid username ${username}`)
+  }
+
+  logger.info(
+    'Auth success with external auth method %s of plugin %s for %s.',
+    authName, npmName, user.email
+  )
+
+  return {
+    bypass: true,
+    pluginName: npmName,
+    authName: authName,
+    user
+  }
+}
+
+function isAuthResultValid (npmName: string, authName: string, result: RegisterServerAuthenticatedResult) {
+  if (!isUserUsernameValid(result.username)) {
+    logger.error('Auth method %s of plugin %s did not provide a valid username.', authName, npmName, { username: result.username })
+    return false
+  }
+
+  if (!result.email) {
+    logger.error('Auth method %s of plugin %s did not provide a valid email.', authName, npmName, { email: result.email })
+    return false
+  }
+
+  // role is optional
+  if (result.role && !isUserRoleValid(result.role)) {
+    logger.error('Auth method %s of plugin %s did not provide a valid role.', authName, npmName, { role: result.role })
+    return false
+  }
+
+  // display name is optional
+  if (result.displayName && !isUserDisplayNameValid(result.displayName)) {
+    logger.error(
+      'Auth method %s of plugin %s did not provide a valid display name.',
+      authName, npmName, { displayName: result.displayName }
+    )
+    return false
+  }
+
+  return true
+}
+
+function buildUserResult (pluginResult: RegisterServerAuthenticatedResult) {
+  return {
+    username: pluginResult.username,
+    email: pluginResult.email,
+    role: pluginResult.role ?? UserRole.USER,
+    displayName: pluginResult.displayName || pluginResult.username
+  }
+}
+
+// ---------------------------------------------------------------------------
+
+export {
+  onExternalUserAuthenticated,
+  getBypassFromExternalAuth,
+  getAuthNameFromRefreshGrant,
+  getBypassFromPasswordGrant
+}
diff --git a/server/lib/auth/oauth-model.ts b/server/lib/auth/oauth-model.ts
new file mode 100644
index 000000000..c74869ee2
--- /dev/null
+++ b/server/lib/auth/oauth-model.ts
@@ -0,0 +1,245 @@
+import { AccessDeniedError } from 'oauth2-server'
+import { PluginManager } from '@server/lib/plugins/plugin-manager'
+import { ActorModel } from '@server/models/activitypub/actor'
+import { MOAuthClient } from '@server/types/models'
+import { MOAuthTokenUser } from '@server/types/models/oauth/oauth-token'
+import { MUser } from '@server/types/models/user/user'
+import { UserAdminFlag } from '@shared/models/users/user-flag.model'
+import { UserRole } from '@shared/models/users/user-role'
+import { logger } from '../../helpers/logger'
+import { CONFIG } from '../../initializers/config'
+import { UserModel } from '../../models/account/user'
+import { OAuthClientModel } from '../../models/oauth/oauth-client'
+import { OAuthTokenModel } from '../../models/oauth/oauth-token'
+import { createUserAccountAndChannelAndPlaylist } from '../user'
+import { TokensCache } from './tokens-cache'
+
+type TokenInfo = {
+  accessToken: string
+  refreshToken: string
+  accessTokenExpiresAt: Date
+  refreshTokenExpiresAt: Date
+}
+
+export type BypassLogin = {
+  bypass: boolean
+  pluginName: string
+  authName?: string
+  user: {
+    username: string
+    email: string
+    displayName: string
+    role: UserRole
+  }
+}
+
+async function getAccessToken (bearerToken: string) {
+  logger.debug('Getting access token (bearerToken: ' + bearerToken + ').')
+
+  if (!bearerToken) return undefined
+
+  let tokenModel: MOAuthTokenUser
+
+  if (TokensCache.Instance.hasToken(bearerToken)) {
+    tokenModel = TokensCache.Instance.getByToken(bearerToken)
+  } else {
+    tokenModel = await OAuthTokenModel.getByTokenAndPopulateUser(bearerToken)
+
+    if (tokenModel) TokensCache.Instance.setToken(tokenModel)
+  }
+
+  if (!tokenModel) return undefined
+
+  if (tokenModel.User.pluginAuth) {
+    const valid = await PluginManager.Instance.isTokenValid(tokenModel, 'access')
+
+    if (valid !== true) return undefined
+  }
+
+  return tokenModel
+}
+
+function getClient (clientId: string, clientSecret: string) {
+  logger.debug('Getting Client (clientId: ' + clientId + ', clientSecret: ' + clientSecret + ').')
+
+  return OAuthClientModel.getByIdAndSecret(clientId, clientSecret)
+}
+
+async function getRefreshToken (refreshToken: string) {
+  logger.debug('Getting RefreshToken (refreshToken: ' + refreshToken + ').')
+
+  const tokenInfo = await OAuthTokenModel.getByRefreshTokenAndPopulateClient(refreshToken)
+  if (!tokenInfo) return undefined
+
+  const tokenModel = tokenInfo.token
+
+  if (tokenModel.User.pluginAuth) {
+    const valid = await PluginManager.Instance.isTokenValid(tokenModel, 'refresh')
+
+    if (valid !== true) return undefined
+  }
+
+  return tokenInfo
+}
+
+async function getUser (usernameOrEmail?: string, password?: string, bypassLogin?: BypassLogin) {
+  // Special treatment coming from a plugin
+  if (bypassLogin && bypassLogin.bypass === true) {
+    logger.info('Bypassing oauth login by plugin %s.', bypassLogin.pluginName)
+
+    let user = await UserModel.loadByEmail(bypassLogin.user.email)
+    if (!user) user = await createUserFromExternal(bypassLogin.pluginName, bypassLogin.user)
+
+    // Cannot create a user
+    if (!user) throw new AccessDeniedError('Cannot create such user: an actor with that name already exists.')
+
+    // If the user does not belongs to a plugin, it was created before its installation
+    // Then we just go through a regular login process
+    if (user.pluginAuth !== null) {
+      // This user does not belong to this plugin, skip it
+      if (user.pluginAuth !== bypassLogin.pluginName) return null
+
+      checkUserValidityOrThrow(user)
+
+      return user
+    }
+  }
+
+  logger.debug('Getting User (username/email: ' + usernameOrEmail + ', password: ******).')
+
+  const user = await UserModel.loadByUsernameOrEmail(usernameOrEmail)
+  // If we don't find the user, or if the user belongs to a plugin
+  if (!user || user.pluginAuth !== null || !password) return null
+
+  const passwordMatch = await user.isPasswordMatch(password)
+  if (passwordMatch !== true) return null
+
+  checkUserValidityOrThrow(user)
+
+  if (CONFIG.SIGNUP.REQUIRES_EMAIL_VERIFICATION && user.emailVerified === false) {
+    throw new AccessDeniedError('User email is not verified.')
+  }
+
+  return user
+}
+
+async function revokeToken (
+  tokenInfo: { refreshToken: string },
+  explicitLogout?: boolean
+): Promise<{ success: boolean, redirectUrl?: string }> {
+  const token = await OAuthTokenModel.getByRefreshTokenAndPopulateUser(tokenInfo.refreshToken)
+
+  if (token) {
+    let redirectUrl: string
+
+    if (explicitLogout === true && token.User.pluginAuth && token.authName) {
+      redirectUrl = await PluginManager.Instance.onLogout(token.User.pluginAuth, token.authName, token.User, this.request)
+    }
+
+    TokensCache.Instance.clearCacheByToken(token.accessToken)
+
+    token.destroy()
+         .catch(err => logger.error('Cannot destroy token when revoking token.', { err }))
+
+    return { success: true, redirectUrl }
+  }
+
+  return { success: false }
+}
+
+async function saveToken (
+  token: TokenInfo,
+  client: MOAuthClient,
+  user: MUser,
+  options: {
+    refreshTokenAuthName?: string
+    bypassLogin?: BypassLogin
+  } = {}
+) {
+  const { refreshTokenAuthName, bypassLogin } = options
+  let authName: string = null
+
+  if (bypassLogin?.bypass === true) {
+    authName = bypassLogin.authName
+  } else if (refreshTokenAuthName) {
+    authName = refreshTokenAuthName
+  }
+
+  logger.debug('Saving token ' + token.accessToken + ' for client ' + client.id + ' and user ' + user.id + '.')
+
+  const tokenToCreate = {
+    accessToken: token.accessToken,
+    accessTokenExpiresAt: token.accessTokenExpiresAt,
+    refreshToken: token.refreshToken,
+    refreshTokenExpiresAt: token.refreshTokenExpiresAt,
+    authName,
+    oAuthClientId: client.id,
+    userId: user.id
+  }
+
+  const tokenCreated = await OAuthTokenModel.create(tokenToCreate)
+
+  user.lastLoginDate = new Date()
+  await user.save()
+
+  return {
+    accessToken: tokenCreated.accessToken,
+    accessTokenExpiresAt: tokenCreated.accessTokenExpiresAt,
+    refreshToken: tokenCreated.refreshToken,
+    refreshTokenExpiresAt: tokenCreated.refreshTokenExpiresAt,
+    client,
+    user,
+    accessTokenExpiresIn: buildExpiresIn(tokenCreated.accessTokenExpiresAt),
+    refreshTokenExpiresIn: buildExpiresIn(tokenCreated.refreshTokenExpiresAt)
+  }
+}
+
+export {
+  getAccessToken,
+  getClient,
+  getRefreshToken,
+  getUser,
+  revokeToken,
+  saveToken
+}
+
+// ---------------------------------------------------------------------------
+
+async function createUserFromExternal (pluginAuth: string, options: {
+  username: string
+  email: string
+  role: UserRole
+  displayName: string
+}) {
+  // Check an actor does not already exists with that name (removed user)
+  const actor = await ActorModel.loadLocalByName(options.username)
+  if (actor) return null
+
+  const userToCreate = new UserModel({
+    username: options.username,
+    password: null,
+    email: options.email,
+    nsfwPolicy: CONFIG.INSTANCE.DEFAULT_NSFW_POLICY,
+    autoPlayVideo: true,
+    role: options.role,
+    videoQuota: CONFIG.USER.VIDEO_QUOTA,
+    videoQuotaDaily: CONFIG.USER.VIDEO_QUOTA_DAILY,
+    adminFlags: UserAdminFlag.NONE,
+    pluginAuth
+  }) as MUser
+
+  const { user } = await createUserAccountAndChannelAndPlaylist({
+    userToCreate,
+    userDisplayName: options.displayName
+  })
+
+  return user
+}
+
+function checkUserValidityOrThrow (user: MUser) {
+  if (user.blocked) throw new AccessDeniedError('User is blocked.')
+}
+
+function buildExpiresIn (expiresAt: Date) {
+  return Math.floor((expiresAt.getTime() - new Date().getTime()) / 1000)
+}
diff --git a/server/lib/auth/oauth.ts b/server/lib/auth/oauth.ts
new file mode 100644
index 000000000..5b6130d56
--- /dev/null
+++ b/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')
+  }
+}
diff --git a/server/lib/auth/tokens-cache.ts b/server/lib/auth/tokens-cache.ts
new file mode 100644
index 000000000..b027ce69a
--- /dev/null
+++ b/server/lib/auth/tokens-cache.ts
@@ -0,0 +1,52 @@
+import * as LRUCache from 'lru-cache'
+import { MOAuthTokenUser } from '@server/types/models'
+import { LRU_CACHE } from '../../initializers/constants'
+
+export class TokensCache {
+
+  private static instance: TokensCache
+
+  private readonly accessTokenCache = new LRUCache<string, MOAuthTokenUser>({ max: LRU_CACHE.USER_TOKENS.MAX_SIZE })
+  private readonly userHavingToken = new LRUCache<number, string>({ max: LRU_CACHE.USER_TOKENS.MAX_SIZE })
+
+  private constructor () { }
+
+  static get Instance () {
+    return this.instance || (this.instance = new this())
+  }
+
+  hasToken (token: string) {
+    return this.accessTokenCache.has(token)
+  }
+
+  getByToken (token: string) {
+    return this.accessTokenCache.get(token)
+  }
+
+  setToken (token: MOAuthTokenUser) {
+    this.accessTokenCache.set(token.accessToken, token)
+    this.userHavingToken.set(token.userId, token.accessToken)
+  }
+
+  deleteUserToken (userId: number) {
+    this.clearCacheByUserId(userId)
+  }
+
+  clearCacheByUserId (userId: number) {
+    const token = this.userHavingToken.get(userId)
+
+    if (token !== undefined) {
+      this.accessTokenCache.del(token)
+      this.userHavingToken.del(userId)
+    }
+  }
+
+  clearCacheByToken (token: string) {
+    const tokenModel = this.accessTokenCache.get(token)
+
+    if (tokenModel !== undefined) {
+      this.userHavingToken.del(tokenModel.userId)
+      this.accessTokenCache.del(token)
+    }
+  }
+}