const ObservableStore = require('obs-store') const SafeEventEmitter = require('safe-event-emitter') const createAsyncMiddleware = require('json-rpc-engine/src/createAsyncMiddleware') /** * A controller that services user-approved requests for a full Ethereum provider API */ class ProviderApprovalController extends SafeEventEmitter { /** * Determines if caching is enabled */ caching = true /** * Creates a ProviderApprovalController * * @param {Object} [config] - Options to configure controller */ constructor ({ closePopup, keyringController, openPopup, preferencesController } = {}) { super() this.approvedOrigins = {} this.closePopup = closePopup this.keyringController = keyringController this.openPopup = openPopup this.preferencesController = preferencesController this.store = new ObservableStore({ providerRequests: [], }) } /** * Called when a user approves access to a full Ethereum provider API * * @param {object} opts - opts for the middleware contains the origin for the middleware */ createMiddleware ({ origin, getSiteMetadata }) { return createAsyncMiddleware(async (req, res, next) => { // only handle requestAccounts if (req.method !== 'eth_requestAccounts') return next() // if already approved or privacy mode disabled, return early if (this.shouldExposeAccounts(origin)) { res.result = [this.preferencesController.getSelectedAddress()] return } // register the provider request const metadata = await getSiteMetadata(origin) this._handleProviderRequest(origin, metadata.name, metadata.icon, false, null) // wait for resolution of request const approved = await new Promise(resolve => this.once(`resolvedRequest:${origin}`, ({ approved }) => resolve(approved))) if (approved) { res.result = [this.preferencesController.getSelectedAddress()] } else { throw new Error('User denied account authorization') } }) } /** * Called when a tab requests access to a full Ethereum provider API * * @param {string} origin - Origin of the window requesting full provider access * @param {string} siteTitle - The title of the document requesting full provider access * @param {string} siteImage - The icon of the window requesting full provider access */ _handleProviderRequest (origin, siteTitle, siteImage, force, tabID) { this.store.updateState({ providerRequests: [{ origin, siteTitle, siteImage, tabID }] }) const isUnlocked = this.keyringController.memStore.getState().isUnlocked if (!force && this.approvedOrigins[origin] && this.caching && isUnlocked) { return } this.openPopup && this.openPopup() } /** * Called when a user approves access to a full Ethereum provider API * * @param {string} origin - origin of the domain that had provider access approved */ approveProviderRequestByOrigin (origin) { this.closePopup && this.closePopup() const requests = this.store.getState().providerRequests const providerRequests = requests.filter(request => request.origin !== origin) this.store.updateState({ providerRequests }) this.approvedOrigins[origin] = true this.emit(`resolvedRequest:${origin}`, { approved: true }) } /** * Called when a tab rejects access to a full Ethereum provider API * * @param {string} origin - origin of the domain that had provider access approved */ rejectProviderRequestByOrigin (origin) { this.closePopup && this.closePopup() const requests = this.store.getState().providerRequests const providerRequests = requests.filter(request => request.origin !== origin) this.store.updateState({ providerRequests }) delete this.approvedOrigins[origin] this.emit(`resolvedRequest:${origin}`, { approved: false }) } /** * Clears any cached approvals for user-approved origins */ clearApprovedOrigins () { this.approvedOrigins = {} } /** * Determines if a given origin should have accounts exposed * * @param {string} origin - Domain origin to check for approval status * @returns {boolean} - True if the origin has been approved */ shouldExposeAccounts (origin) { const privacyMode = this.preferencesController.getFeatureFlags().privacyMode const result = !privacyMode || Boolean(this.approvedOrigins[origin]) return result } } module.exports = ProviderApprovalController