const EventEmitter = require('events') const ObservableStore = require('obs-store') const ethUtil = require('ethereumjs-util') const createId = require('./random-id') const hexRe = /^[0-9A-Fa-f]+$/g const log = require('loglevel') /** * Represents, and contains data about, an 'personal_sign' type signature request. These are created when a * signature for an personal_sign call is requested. * * @see {@link https://web3js.readthedocs.io/en/1.0/web3-eth-personal.html#sign} * * @typedef {Object} PersonalMessage * @property {number} id An id to track and identify the message object * @property {Object} msgParams The parameters to pass to the personal_sign method once the signature request is * approved. * @property {Object} msgParams.metamaskId Added to msgParams for tracking and identification within MetaMask. * @property {string} msgParams.data A hex string conversion of the raw buffer data of the signature request * @property {number} time The epoch time at which the this message was created * @property {string} status Indicates whether the signature request is 'unapproved', 'approved', 'signed' or 'rejected' * @property {string} type The json-prc signing method for which a signature request has been made. A 'Message' will * always have a 'personal_sign' type. * */ module.exports = class PersonalMessageManager extends EventEmitter { /** * Controller in charge of managing - storing, adding, removing, updating - PersonalMessage. * * @typedef {Object} PersonalMessageManager * @param {Object} opts @deprecated * @property {Object} memStore The observable store where PersonalMessage are saved with persistance. * @property {Object} memStore.unapprovedPersonalMsgs A collection of all PersonalMessages in the 'unapproved' state * @property {number} memStore.unapprovedPersonalMsgCount The count of all PersonalMessages in this.memStore.unapprobedMsgs * @property {array} messages Holds all messages that have been created by this PersonalMessageManager * */ constructor (opts) { super() this.memStore = new ObservableStore({ unapprovedPersonalMsgs: {}, unapprovedPersonalMsgCount: 0, }) this.messages = [] } /** * A getter for the number of 'unapproved' PersonalMessages in this.messages * * @returns {number} The number of 'unapproved' PersonalMessages in this.messages * */ get unapprovedPersonalMsgCount () { return Object.keys(this.getUnapprovedMsgs()).length } /** * A getter for the 'unapproved' PersonalMessages in this.messages * * @returns {Object} An index of PersonalMessage ids to PersonalMessages, for all 'unapproved' PersonalMessages in * this.messages * */ getUnapprovedMsgs () { return this.messages.filter(msg => msg.status === 'unapproved') .reduce((result, msg) => { result[msg.id] = msg; return result }, {}) } /** * Creates a new PersonalMessage with an 'unapproved' status using the passed msgParams. this.addMsg is called to add * the new PersonalMessage to this.messages, and to save the unapproved PersonalMessages from that list to * this.memStore. * * @param {Object} msgParams The params for the eth_sign call to be made after the message is approved. * @param {Object} req (optional) The original request object possibly containing the origin * @returns {promise} When the message has been signed or rejected * */ addUnapprovedMessageAsync (msgParams, req) { return new Promise((resolve, reject) => { if (!msgParams.from) { reject(new Error('MetaMask Message Signature: from field is required.')) } const msgId = this.addUnapprovedMessage(msgParams, req) this.once(`${msgId}:finished`, (data) => { switch (data.status) { case 'signed': return resolve(data.rawSig) case 'rejected': return reject(new Error('MetaMask Message Signature: User denied message signature.')) default: return reject(new Error(`MetaMask Message Signature: Unknown problem: ${JSON.stringify(msgParams)}`)) } }) }) } /** * Creates a new PersonalMessage with an 'unapproved' status using the passed msgParams. this.addMsg is called to add * the new PersonalMessage to this.messages, and to save the unapproved PersonalMessages from that list to * this.memStore. * * @param {Object} msgParams The params for the eth_sign call to be made after the message is approved. * @param {Object} req (optional) The original request object possibly containing the origin * @returns {number} The id of the newly created PersonalMessage. * */ addUnapprovedMessage (msgParams, req) { log.debug(`PersonalMessageManager addUnapprovedMessage: ${JSON.stringify(msgParams)}`) // add origin from request if (req) msgParams.origin = req.origin msgParams.data = this.normalizeMsgData(msgParams.data) // create txData obj with parameters and meta data var time = (new Date()).getTime() var msgId = createId() var msgData = { id: msgId, msgParams: msgParams, time: time, status: 'unapproved', type: 'personal_sign', } this.addMsg(msgData) // signal update this.emit('update') return msgId } /** * Adds a passed PersonalMessage to this.messages, and calls this._saveMsgList() to save the unapproved PersonalMessages from that * list to this.memStore. * * @param {Message} msg The PersonalMessage to add to this.messages * */ addMsg (msg) { this.messages.push(msg) this._saveMsgList() } /** * Returns a specified PersonalMessage. * * @param {number} msgId The id of the PersonalMessage to get * @returns {PersonalMessage|undefined} The PersonalMessage with the id that matches the passed msgId, or undefined * if no PersonalMessage has that id. * */ getMsg (msgId) { return this.messages.find(msg => msg.id === msgId) } /** * Approves a PersonalMessage. Sets the message status via a call to this.setMsgStatusApproved, and returns a promise * with any the message params modified for proper signing. * * @param {Object} msgParams The msgParams to be used when eth_sign is called, plus data added by MetaMask. * @param {Object} msgParams.metamaskId Added to msgParams for tracking and identification within MetaMask. * @returns {Promise} Promises the msgParams object with metamaskId removed. * */ approveMessage (msgParams) { this.setMsgStatusApproved(msgParams.metamaskId) return this.prepMsgForSigning(msgParams) } /** * Sets a PersonalMessage status to 'approved' via a call to this._setMsgStatus. * * @param {number} msgId The id of the PersonalMessage to approve. * */ setMsgStatusApproved (msgId) { this._setMsgStatus(msgId, 'approved') } /** * Sets a PersonalMessage status to 'signed' via a call to this._setMsgStatus and updates that PersonalMessage in * this.messages by adding the raw signature data of the signature request to the PersonalMessage * * @param {number} msgId The id of the PersonalMessage to sign. * @param {buffer} rawSig The raw data of the signature request * */ setMsgStatusSigned (msgId, rawSig) { const msg = this.getMsg(msgId) msg.rawSig = rawSig this._updateMsg(msg) this._setMsgStatus(msgId, 'signed') } /** * Removes the metamaskId property from passed msgParams and returns a promise which resolves the updated msgParams * * @param {Object} msgParams The msgParams to modify * @returns {Promise} Promises the msgParams with the metamaskId property removed * */ prepMsgForSigning (msgParams) { delete msgParams.metamaskId return Promise.resolve(msgParams) } /** * Sets a PersonalMessage status to 'rejected' via a call to this._setMsgStatus. * * @param {number} msgId The id of the PersonalMessage to reject. * */ rejectMsg (msgId) { this._setMsgStatus(msgId, 'rejected') } /** * Updates the status of a PersonalMessage in this.messages via a call to this._updateMsg * * @private * @param {number} msgId The id of the PersonalMessage to update. * @param {string} status The new status of the PersonalMessage. * @throws A 'PersonalMessageManager - PersonalMessage not found for id: "${msgId}".' if there is no PersonalMessage * in this.messages with an id equal to the passed msgId * @fires An event with a name equal to `${msgId}:${status}`. The PersonalMessage is also fired. * @fires If status is 'rejected' or 'signed', an event with a name equal to `${msgId}:finished` is fired along * with the PersonalMessage * */ _setMsgStatus (msgId, status) { const msg = this.getMsg(msgId) if (!msg) throw new Error('PersonalMessageManager - Message not found for id: "${msgId}".') msg.status = status this._updateMsg(msg) this.emit(`${msgId}:${status}`, msg) if (status === 'rejected' || status === 'signed') { this.emit(`${msgId}:finished`, msg) } } /** * Sets a PersonalMessage in this.messages to the passed PersonalMessage if the ids are equal. Then saves the * unapprovedPersonalMsgs index to storage via this._saveMsgList * * @private * @param {msg} PersonalMessage A PersonalMessage that will replace an existing PersonalMessage (with the same * id) in this.messages * */ _updateMsg (msg) { const index = this.messages.findIndex((message) => message.id === msg.id) if (index !== -1) { this.messages[index] = msg } this._saveMsgList() } /** * Saves the unapproved PersonalMessages, and their count, to this.memStore * * @private * @fires 'updateBadge' * */ _saveMsgList () { const unapprovedPersonalMsgs = this.getUnapprovedMsgs() const unapprovedPersonalMsgCount = Object.keys(unapprovedPersonalMsgs).length this.memStore.updateState({ unapprovedPersonalMsgs, unapprovedPersonalMsgCount }) this.emit('updateBadge') } /** * A helper function that converts raw buffer data to a hex, or just returns the data if it is already formatted as a hex. * * @param {any} data The buffer data to convert to a hex * @returns {string} A hex string conversion of the buffer data * */ normalizeMsgData (data) { try { const stripped = ethUtil.stripHexPrefix(data) if (stripped.match(hexRe)) { return ethUtil.addHexPrefix(stripped) } } catch (e) { log.debug(`Message was not hex encoded, interpreting as utf8.`) } return ethUtil.bufferToHex(new Buffer(data, 'utf8')) } }