/* This file is part of TALER (C) 2015 GNUnet e.V. TALER is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. TALER is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with TALER; see the file COPYING. If not, If not, see */ /** * High-level wallet operations that should be indepentent from the underlying * browser extension interface. * @module Wallet * @author Florian Dold */ import {AmountJson, CreateReserveResponse, IExchangeInfo, Denomination, Notifier} from "./types"; import {HttpResponse, RequestException} from "./http"; import {Query} from "./query"; import {Checkable} from "./checkable"; import {canonicalizeBaseUrl} from "./helpers"; import {ReserveCreationInfo, Amounts} from "./types"; import {PreCoin} from "./types"; import {Reserve} from "./types"; import {CryptoApi} from "./cryptoApi"; import {Coin} from "./types"; import {PayCoinInfo} from "./types"; import {CheckRepurchaseResult} from "./types"; import {Contract} from "./types"; import {ExchangeHandle} from "./types"; "use strict"; export interface CoinWithDenom { coin: Coin; denom: Denomination; } @Checkable.Class export class KeysJson { @Checkable.List(Checkable.Value(Denomination)) denoms: Denomination[]; @Checkable.String master_public_key: string; @Checkable.Any auditors: any[]; @Checkable.String list_issue_date: string; @Checkable.Any signkeys: any; @Checkable.String eddsa_pub: string; @Checkable.String eddsa_sig: string; static checked: (obj: any) => KeysJson; } class ExchangeInfo implements IExchangeInfo { baseUrl: string; masterPublicKey: string; denoms: Denomination[]; constructor(obj: {baseUrl: string} & any) { this.baseUrl = obj.baseUrl; if (obj.denoms) { this.denoms = Array.from(obj.denoms); } else { this.denoms = []; } if (typeof obj.masterPublicKey === "string") { this.masterPublicKey = obj.masterPublicKey; } } static fresh(baseUrl: string): ExchangeInfo { return new ExchangeInfo({baseUrl}); } /** * Merge new key information into the exchange info. * If the new key information is invalid (missing fields, * invalid signatures), an exception is thrown, but the * exchange info is updated with the new information up until * the first error. */ mergeKeys(newKeys: KeysJson, cryptoApi: CryptoApi): Promise { if (!this.masterPublicKey) { this.masterPublicKey = newKeys.master_public_key; } if (this.masterPublicKey != newKeys.master_public_key) { throw Error("public keys do not match"); } let ps = newKeys.denoms.map((newDenom) => { let found = false; for (let oldDenom of this.denoms) { if (oldDenom.denom_pub === newDenom.denom_pub) { let a = Object.assign({}, oldDenom); let b = Object.assign({}, newDenom); // pub hash is only there for convenience in the wallet delete a["pub_hash"]; delete b["pub_hash"]; if (!deepEquals(a, b)) { console.log("old/new:"); console.dir(a); console.dir(b); throw Error("denomination modified"); } found = true; break; } } if (found) { return Promise.resolve(); } return cryptoApi .isValidDenom(newDenom, this.masterPublicKey) .then((valid) => { if (!valid) { throw Error("signature on denomination invalid"); } return cryptoApi.hashRsaPub(newDenom.denom_pub); }) .then((h) => { this.denoms.push(Object.assign({}, newDenom, {pub_hash: h})); }); }); return Promise.all(ps).then(() => void 0); } } @Checkable.Class export class CreateReserveRequest { /** * The initial amount for the reserve. */ @Checkable.Value(AmountJson) amount: AmountJson; /** * Exchange URL where the bank should create the reserve. */ @Checkable.String exchange: string; static checked: (obj: any) => CreateReserveRequest; } @Checkable.Class export class ConfirmReserveRequest { /** * Public key of then reserve that should be marked * as confirmed. */ @Checkable.String reservePub: string; static checked: (obj: any) => ConfirmReserveRequest; } @Checkable.Class export class Offer { @Checkable.Value(Contract) contract: Contract; @Checkable.String merchant_sig: string; @Checkable.String H_contract: string; static checked: (obj: any) => Offer; } interface ConfirmPayRequest { offer: Offer; } interface ExchangeCoins { [exchangeUrl: string]: CoinWithDenom[]; } interface CoinPaySig { coin_sig: string; coin_pub: string; ub_sig: string; denom_pub: string; f: AmountJson; } interface Transaction { contractHash: string; contract: Contract; payReq: any; merchantSig: string; } export interface Badge { setText(s: string): void; setColor(c: string): void; } function deepEquals(x, y) { if (x === y) { return true; } if (Array.isArray(x) && x.length !== y.length) { return false; } var p = Object.keys(x); return Object.keys(y).every((i) => p.indexOf(i) !== -1) && p.every((i) => deepEquals(x[i], y[i])); } function getTalerStampSec(stamp: string) { const m = stamp.match(/\/?Date\(([0-9]*)\)\/?/); if (!m) { return null; } return parseInt(m[1]); } function isWithdrawableDenom(d: Denomination) { const now_sec = (new Date).getTime() / 1000; const stamp_withdraw_sec = getTalerStampSec(d.stamp_expire_withdraw); // Withdraw if still possible to withdraw within a minute if (stamp_withdraw_sec + 60 > now_sec) { return true; } return false; } interface HttpRequestLibrary { req(method: string, url: string|uri.URI, options?: any): Promise; get(url: string|uri.URI): Promise; postJson(url: string|uri.URI, body): Promise; postForm(url: string|uri.URI, form): Promise; } function copy(o) { return JSON.parse(JSON.stringify(o)); } /** * Get a list of denominations (with repetitions possible) * whose total value is as close as possible to the available * amount, but never larger. */ function getWithdrawDenomList(amountAvailable: AmountJson, denoms: Denomination[]): Denomination[] { let remaining = Amounts.copy(amountAvailable); let ds: Denomination[] = []; denoms = denoms.filter(isWithdrawableDenom); denoms.sort((d1, d2) => Amounts.cmp(d2.value, d1.value)); // This is an arbitrary number of coins // we can withdraw in one go. It's not clear if this limit // is useful ... for (let i = 0; i < 1000; i++) { let found = false; for (let d of denoms) { let cost = Amounts.add(d.value, d.fee_withdraw).amount; if (Amounts.cmp(remaining, cost) < 0) { continue; } found = true; remaining = Amounts.sub(remaining, cost).amount; ds.push(d); break; } if (!found) { break; } } return ds; } export class Wallet { private db: IDBDatabase; private http: HttpRequestLibrary; private badge: Badge; private notifier: Notifier; public cryptoApi: CryptoApi; constructor(db: IDBDatabase, http: HttpRequestLibrary, badge: Badge, notifier: Notifier) { this.db = db; this.http = http; this.badge = badge; this.notifier = notifier; this.cryptoApi = new CryptoApi(); } /** * Get exchanges and associated coins that are still spendable, * but only if the sum the coins' remaining value exceeds the payment amount. */ private getPossibleExchangeCoins(paymentAmount: AmountJson, depositFeeLimit: AmountJson, allowedExchanges: ExchangeHandle[]): Promise { // Mapping from exchange base URL to list of coins together with their // denomination let m: ExchangeCoins = {}; function storeExchangeCoin(mc, url) { let exchange: IExchangeInfo = mc[0]; console.log("got coin for exchange", url); let coin: Coin = mc[1]; let cd = { coin: coin, denom: exchange.denoms.find((e) => e.denom_pub === coin.denomPub) }; if (!cd.denom) { throw Error("denom not found (database inconsistent)"); } if (cd.denom.value.currency !== paymentAmount.currency) { console.warn("same pubkey for different currencies"); return; } let x = m[url]; if (!x) { m[url] = [cd]; } else { x.push(cd); } } // Make sure that we don't look up coins // for the same URL twice ... let handledExchanges = new Set(); let ps = allowedExchanges.map((info: ExchangeHandle) => { if (handledExchanges.has(info.url)) { return; } handledExchanges.add(info.url); console.log("Checking for merchant's exchange", JSON.stringify(info)); return Query(this.db) .iter("exchanges", {indexName: "pubKey", only: info.master_pub}) .indexJoin("coins", "exchangeBaseUrl", (exchange) => exchange.baseUrl) .reduce((x) => storeExchangeCoin(x, info.url)); }); return Promise.all(ps).then(() => { let ret: ExchangeCoins = {}; if (Object.keys(m).length == 0) { console.log("not suitable exchanges found"); } console.dir(m); // We try to find the first exchange where we have // enough coins to cover the paymentAmount with fees // under depositFeeLimit nextExchange: for (let key in m) { let coins = m[key]; console.log("trying coins"); console.log(coins); // Sort by ascending deposit fee coins.sort((o1, o2) => Amounts.cmp(o1.denom.fee_deposit, o2.denom.fee_deposit)); let maxFee = Amounts.copy(depositFeeLimit); let minAmount = Amounts.copy(paymentAmount); let accFee = Amounts.copy(coins[0].denom.fee_deposit); let accAmount = Amounts.getZero(coins[0].coin.currentAmount.currency); let usableCoins: CoinWithDenom[] = []; nextCoin: for (let i = 0; i < coins.length; i++) { let coinAmount = Amounts.copy(coins[i].coin.currentAmount); let coinFee = coins[i].denom.fee_deposit; if (Amounts.cmp(coinAmount, coinFee) <= 0) { continue nextCoin; } accFee = Amounts.add(accFee, coinFee).amount; accAmount = Amounts.add(accAmount, coinAmount).amount; if (Amounts.cmp(accFee, maxFee) >= 0) { // FIXME: if the fees are too high, we have // to cover them ourselves .... console.log("too much fees"); continue nextExchange; } usableCoins.push(coins[i]); if (Amounts.cmp(accAmount, minAmount) >= 0) { ret[key] = usableCoins; continue nextExchange; } } } return ret; }); } /** * Record all information that is necessary to * pay for a contract in the wallet's database. */ private recordConfirmPay(offer: Offer, payCoinInfo: PayCoinInfo, chosenExchange: string): Promise { let payReq = {}; payReq["amount"] = offer.contract.amount; payReq["coins"] = payCoinInfo.map((x) => x.sig); payReq["H_contract"] = offer.H_contract; payReq["max_fee"] = offer.contract.max_fee; payReq["merchant_sig"] = offer.merchant_sig; payReq["exchange"] = URI(chosenExchange).href(); payReq["refund_deadline"] = offer.contract.refund_deadline; payReq["timestamp"] = offer.contract.timestamp; payReq["transaction_id"] = offer.contract.transaction_id; let t: Transaction = { contractHash: offer.H_contract, contract: offer.contract, payReq: payReq, merchantSig: offer.merchant_sig, }; console.log("pay request"); console.dir(payReq); let historyEntry = { type: "pay", timestamp: (new Date).getTime(), detail: { merchantName: offer.contract.merchant.name, amount: offer.contract.amount, contractHash: offer.H_contract, fulfillmentUrl: offer.contract.fulfillment_url } }; return Query(this.db) .put("transactions", t) .put("history", historyEntry) .putAll("coins", payCoinInfo.map((pci) => pci.updatedCoin)) .finish() .then(() => { this.notifier.notify(); }); } /** * Add a contract to the wallet and sign coins, * but do not send them yet. */ confirmPay(offer: Offer): Promise { console.log("executing confirmPay"); return Promise.resolve().then(() => { return this.getPossibleExchangeCoins(offer.contract.amount, offer.contract.max_fee, offer.contract.exchanges) }).then((mcs) => { if (Object.keys(mcs).length == 0) { console.log("not confirming payment, insufficient coins"); return { error: "coins-insufficient", }; } let exchangeUrl = Object.keys(mcs)[0]; return this.cryptoApi.signDeposit(offer, mcs[exchangeUrl]) .then((ds) => this.recordConfirmPay(offer, ds, exchangeUrl)) .then(() => ({})); }); } /** * Retrieve all necessary information for looking up the contract * with the given hash. */ executePayment(H_contract): Promise { return Promise.resolve().then(() => { return Query(this.db) .get("transactions", H_contract) .then((t) => { if (!t) { return { success: false, contractFound: false, } } let resp = { success: true, payReq: t.payReq, contract: t.contract, }; return resp; }); }); } /** * First fetch information requred to withdraw from the reserve, * then deplete the reserve, withdrawing coins until it is empty. */ private initReserve(reserveRecord) { this.updateExchangeFromUrl(reserveRecord.exchange_base_url) .then((exchange) => this.updateReserve(reserveRecord.reserve_pub, exchange) .then((reserve) => this.depleteReserve(reserve, exchange))) .then(() => { let depleted = { type: "depleted-reserve", timestamp: (new Date).getTime(), detail: { reservePub: reserveRecord.reserve_pub, } }; return Query(this.db).put("history", depleted).finish(); }) .catch((e) => { console.error("Failed to deplete reserve"); console.error(e); }); } /** * Create a reserve, but do not flag it as confirmed yet. */ createReserve(req: CreateReserveRequest): Promise { return this.cryptoApi.createEddsaKeypair().then((keypair) => { const now = (new Date).getTime(); const canonExchange = canonicalizeBaseUrl(req.exchange); const reserveRecord = { reserve_pub: keypair.pub, reserve_priv: keypair.priv, exchange_base_url: canonExchange, created: now, last_query: null, current_amount: null, requested_amount: req.amount, confirmed: false, }; const historyEntry = { type: "create-reserve", timestamp: now, detail: { requestedAmount: req.amount, reservePub: reserveRecord.reserve_pub, } }; return Query(this.db) .put("reserves", reserveRecord) .put("history", historyEntry) .finish() .then(() => { let r: CreateReserveResponse = { exchange: canonExchange, reservePub: keypair.pub, }; return r; }); }); } /** * Mark an existing reserve as confirmed. The wallet will start trying * to withdraw from that reserve. This may not immediately succeed, * since the exchange might not know about the reserve yet, even though the * bank confirmed its creation. * * A confirmed reserve should be shown to the user in the UI, while * an unconfirmed reserve should be hidden. */ confirmReserve(req: ConfirmReserveRequest): Promise { const now = (new Date).getTime(); const historyEntry = { type: "confirm-reserve", timestamp: now, detail: { reservePub: req.reservePub, } }; return Query(this.db) .get("reserves", req.reservePub) .then((r) => { r.confirmed = true; return Query(this.db) .put("reserves", r) .put("history", historyEntry) .finish() .then(() => { // Do this in the background this.initReserve(r); }); }); } private withdrawExecute(pc: PreCoin): Promise { return Query(this.db) .get("reserves", pc.reservePub) .then((r) => { let wd: any = {}; wd.denom_pub = pc.denomPub; wd.reserve_pub = pc.reservePub; wd.reserve_sig = pc.withdrawSig; wd.coin_ev = pc.coinEv; let reqUrl = URI("reserve/withdraw").absoluteTo(r.exchange_base_url); return this.http.postJson(reqUrl, wd); }) .then(resp => { if (resp.status != 200) { throw new RequestException({ hint: "Withdrawal failed", status: resp.status }); } let r = JSON.parse(resp.responseText); return this.cryptoApi.rsaUnblind(r.ev_sig, pc.blindingKey, pc.denomPub) .then((denomSig) => { let coin: Coin = { coinPub: pc.coinPub, coinPriv: pc.coinPriv, denomPub: pc.denomPub, denomSig: denomSig, currentAmount: pc.coinValue, exchangeBaseUrl: pc.exchangeBaseUrl, }; return coin; }); }); } storeCoin(coin: Coin): Promise { let historyEntry = { type: "withdraw", timestamp: (new Date).getTime(), detail: { coinPub: coin.coinPub, } }; return Query(this.db) .delete("precoins", coin.coinPub) .add("coins", coin) .add("history", historyEntry) .finish() .then(() => { this.notifier.notify(); }); } /** * Withdraw one coins of the given denomination from the given reserve. */ private withdraw(denom: Denomination, reserve: Reserve): Promise { console.log("creating pre coin at", new Date()); return this.cryptoApi .createPreCoin(denom, reserve) .then((preCoin) => { return Query(this.db) .put("precoins", preCoin) .finish() .then(() => this.withdrawExecute(preCoin)) .then((c) => this.storeCoin(c)); }); } /** * Withdraw coins from a reserve until it is empty. */ private depleteReserve(reserve, exchange: ExchangeInfo): Promise { let denomsAvailable: Denomination[] = copy(exchange.denoms); let denomsForWithdraw = getWithdrawDenomList(reserve.current_amount, denomsAvailable); let ps = denomsForWithdraw.map((denom) => { console.log("withdrawing", JSON.stringify(denom)); // Do the withdraw asynchronously, so crypto is interleaved // with requests return this.withdraw(denom, reserve); }); return Promise.all(ps).then(() => void 0); } /** * Update the information about a reserve that is stored in the wallet * by quering the reserve's exchange. */ private updateReserve(reservePub: string, exchange: ExchangeInfo): Promise { return Query(this.db) .get("reserves", reservePub) .then((reserve) => { let reqUrl = URI("reserve/status").absoluteTo(exchange.baseUrl); reqUrl.query({'reserve_pub': reservePub}); return this.http.get(reqUrl).then(resp => { if (resp.status != 200) { throw Error(); } let reserveInfo = JSON.parse(resp.responseText); if (!reserveInfo) { throw Error(); } let oldAmount = reserve.current_amount; let newAmount = reserveInfo.balance; reserve.current_amount = reserveInfo.balance; let historyEntry = { type: "reserve-update", timestamp: (new Date).getTime(), detail: { reservePub, oldAmount, newAmount } }; return Query(this.db) .put("reserves", reserve) .finish() .then(() => reserve); }); }); } getReserveCreationInfo(baseUrl: string, amount: AmountJson): Promise { return this.updateExchangeFromUrl(baseUrl) .then((exchangeInfo: IExchangeInfo) => { let selectedDenoms = getWithdrawDenomList(amount, exchangeInfo.denoms); let acc = Amounts.getZero(amount.currency); for (let d of selectedDenoms) { acc = Amounts.add(acc, d.fee_withdraw).amount; } let actualCoinCost = selectedDenoms .map((d: Denomination) => Amounts.add(d.value, d.fee_withdraw).amount) .reduce((a, b) => Amounts.add(a, b).amount); let ret: ReserveCreationInfo = { exchangeInfo, selectedDenoms, withdrawFee: acc, overhead: Amounts.sub(amount, actualCoinCost).amount, }; return ret; }); } /** * Update or add exchange DB entry by fetching the /keys information. * Optionally link the reserve entry to the new or existing * exchange entry in then DB. */ updateExchangeFromUrl(baseUrl): Promise { baseUrl = canonicalizeBaseUrl(baseUrl); let reqUrl = URI("keys").absoluteTo(baseUrl); return this.http.get(reqUrl).then((resp) => { if (resp.status != 200) { throw Error("/keys request failed"); } let exchangeKeysJson = KeysJson.checked(JSON.parse(resp.responseText)); return Query(this.db).get("exchanges", baseUrl).then((r) => { let exchangeInfo; console.dir(r); if (!r) { exchangeInfo = ExchangeInfo.fresh(baseUrl); console.log("making fresh exchange"); } else { exchangeInfo = new ExchangeInfo(r); console.log("using old exchange"); } return exchangeInfo.mergeKeys(exchangeKeysJson, this.cryptoApi) .then(() => { return Query(this.db) .put("exchanges", exchangeInfo) .finish() .then(() => exchangeInfo); }); }); }); } /** * Retrieve a mapping from currency name to the amount * that is currenctly available for spending in the wallet. */ getBalances(): Promise { function collectBalances(c: Coin, byCurrency) { let acc: AmountJson = byCurrency[c.currentAmount.currency]; if (!acc) { acc = Amounts.getZero(c.currentAmount.currency); } byCurrency[c.currentAmount.currency] = Amounts.add(c.currentAmount, acc).amount; return byCurrency; } return Query(this.db) .iter("coins") .reduce(collectBalances, {}) .then(byCurrency => { return {balances: byCurrency}; }); } /** * Retrive the full event history for this wallet. */ getHistory(): Promise { function collect(x, acc) { acc.push(x); return acc; } return Query(this.db) .iter("history", {indexName: "timestamp"}) .reduce(collect, []) .then(acc => ({history: acc})); } checkRepurchase(contract: Contract): Promise { if (!contract.repurchase_correlation_id) { console.log("no repurchase: no correlation id"); return Promise.resolve({isRepurchase: false}); } return Query(this.db) .getIndexed("transactions", "repurchase", [contract.merchant_pub, contract.repurchase_correlation_id]) .then((result: Transaction) => { console.log("db result", result); let isRepurchase; if (result) { console.assert(result.contract.repurchase_correlation_id == contract.repurchase_correlation_id); return { isRepurchase: true, existingContractHash: result.contractHash, existingFulfillmentUrl: result.contract.fulfillment_url, }; } else { return {isRepurchase: false}; } }); } }