/*
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, see
*/
/**
* High-level wallet operations that should be indepentent from the underlying
* browser extension interface.
*/
/**
* Imports.
*/
import {Checkable} from "./checkable";
import {CryptoApi} from "./crypto/cryptoApi";
import {
amountToPretty,
canonicalJson,
canonicalizeBaseUrl,
getTalerStampSec,
} from "./helpers";
import {
HttpRequestLibrary,
RequestException,
} from "./http";
import * as LibtoolVersion from "./libtoolVersion";
import {
AbortTransaction,
Index,
JoinLeftResult,
JoinResult,
QueryRoot,
Store,
} from "./query";
import {TimerGroup} from "./timer";
import {
AmountJson,
Amounts,
Auditor,
CheckPayResult,
CoinPaySig,
CoinRecord,
CoinStatus,
ConfirmPayResult,
ConfirmReserveRequest,
ContractTerms,
CreateReserveRequest,
CreateReserveResponse,
CurrencyRecord,
Denomination,
DenominationRecord,
DenominationStatus,
ExchangeHandle,
ExchangeRecord,
ExchangeWireFeesRecord,
HistoryLevel,
HistoryRecord,
Notifier,
PayCoinInfo,
PayReq,
PaybackConfirmation,
PreCoinRecord,
ProposalRecord,
QueryPaymentResult,
RefreshSessionRecord,
ReserveCreationInfo,
ReserveRecord,
ReturnCoinsRequest,
SenderWireInfos,
WalletBalance,
WalletBalanceEntry,
WireFee,
WireInfo,
RefundPermission,
PurchaseRecord,
} from "./types";
import URI = require("urijs");
/**
* Named tuple of coin and denomination.
*/
export interface CoinWithDenom {
/**
* A coin. Must have the same denomination public key as the associated
* denomination.
*/
coin: CoinRecord;
/**
* An associated denomination.
*/
denom: DenominationRecord;
}
/**
* Element of the payback list that the
* exchange gives us in /keys.
*/
@Checkable.Class()
export class Payback {
/**
* The hash of the denomination public key for which the payback is offered.
*/
@Checkable.String
h_denom_pub: string;
}
/**
* Structure that the exchange gives us in /keys.
*/
@Checkable.Class({extra: true})
export class KeysJson {
/**
* List of offered denominations.
*/
@Checkable.List(Checkable.Value(Denomination))
denoms: Denomination[];
/**
* The exchange's master public key.
*/
@Checkable.String
master_public_key: string;
/**
* The list of auditors (partially) auditing the exchange.
*/
@Checkable.List(Checkable.Value(Auditor))
auditors: Auditor[];
/**
* Timestamp when this response was issued.
*/
@Checkable.String
list_issue_date: string;
/**
* List of paybacks for compromised denominations.
*/
@Checkable.Optional(Checkable.List(Checkable.Value(Payback)))
payback?: Payback[];
/**
* Short-lived signing keys used to sign online
* responses.
*/
@Checkable.Any
signkeys: any;
/**
* Protocol version.
*/
@Checkable.Optional(Checkable.String)
version?: string;
/**
* Verify that a value matches the schema of this class and convert it into a
* member.
*/
static checked: (obj: any) => KeysJson;
}
/**
* Wire fees as anounced by the exchange.
*/
@Checkable.Class()
class WireFeesJson {
/**
* Cost of a wire transfer.
*/
@Checkable.Value(AmountJson)
wire_fee: AmountJson;
/**
* Cost of clising a reserve.
*/
@Checkable.Value(AmountJson)
closing_fee: AmountJson;
/**
* Signature made with the exchange's master key.
*/
@Checkable.String
sig: string;
/**
* Date from which the fee applies.
*/
@Checkable.String
start_date: string;
/**
* Data after which the fee doesn't apply anymore.
*/
@Checkable.String
end_date: string;
/**
* Verify that a value matches the schema of this class and convert it into a
* member.
*/
static checked: (obj: any) => WireFeesJson;
}
/**
* Information about wire transfer methods supported
* by the exchange.
*/
@Checkable.Class({extra: true})
class WireDetailJson {
/**
* Name of the wire transfer method.
*/
@Checkable.String
type: string;
/**
* Fees associated with the wire transfer method.
*/
@Checkable.List(Checkable.Value(WireFeesJson))
fees: WireFeesJson[];
/**
* Verify that a value matches the schema of this class and convert it into a
* member.
*/
static checked: (obj: any) => WireDetailJson;
}
/**
* Badge that shows activity for the wallet.
*/
export interface Badge {
/**
* Start indicating background activity.
*/
startBusy(): void;
/**
* Stop indicating background activity.
*/
stopBusy(): void;
}
/**
* Nonce record as stored in the wallet's database.
*/
export interface NonceRecord {
priv: string;
pub: string;
}
/**
* Configuration key/value entries to configure
* the wallet.
*/
export interface ConfigRecord {
key: string;
value: any;
}
/**
* Coin that we're depositing ourselves.
*/
export interface DepositCoin {
coinPaySig: CoinPaySig;
/**
* Undefined if coin not deposited, otherwise signature
* from the exchange confirming the deposit.
*/
depositedSig?: string;
}
export interface CoinsReturnRecord {
/**
* Hash of the contract for sending coins to our own bank account.
*/
contractTermsHash: string;
contractTerms: ContractTerms;
/**
* Private key where corresponding
* public key is used in the contract terms
* as merchant pub.
*/
merchantPriv: string;
coins: DepositCoin[];
/**
* Exchange base URL to deposit coins at.
*/
exchange: string;
/**
* Our own wire information for the deposit.
*/
wire: any;
}
/**
* Wallet protocol version spoken with the exchange
* and merchant.
*
* Uses libtool's current:revision:age versioning.
*/
export const WALLET_PROTOCOL_VERSION = "0:0:0";
/**
* Current database version, should be incremented
* each time we do incompatible schema changes on the database.
* In the future we might consider adding migration functions for
* each version increment.
*/
export const WALLET_DB_VERSION = 19;
const builtinCurrencies: CurrencyRecord[] = [
{
auditors: [
{
auditorPub: "BW9DC48PHQY4NH011SHHX36DZZ3Q22Y6X7FZ1VD1CMZ2PTFZ6PN0",
baseUrl: "https://auditor.demo.taler.net/",
expirationStamp: (new Date(2027, 1)).getTime(),
},
],
exchanges: [],
fractionalDigits: 2,
name: "KUDOS",
},
];
function isWithdrawableDenom(d: DenominationRecord) {
const nowSec = (new Date()).getTime() / 1000;
const stampWithdrawSec = getTalerStampSec(d.stampExpireWithdraw);
if (stampWithdrawSec === null) {
return false;
}
const stampStartSec = getTalerStampSec(d.stampStart);
if (stampStartSec === null) {
return false;
}
// Withdraw if still possible to withdraw within a minute
if ((stampWithdrawSec + 60 > nowSec) && (nowSec >= stampStartSec)) {
return true;
}
return false;
}
/**
* Result of selecting coins, contains the exchange, and selected
* coins with their denomination.
*/
export type CoinSelectionResult = {exchangeUrl: string, cds: CoinWithDenom[]}|undefined;
/**
* Select coins for a payment under the merchant's constraints.
*/
export function selectPayCoins(cds: CoinWithDenom[], paymentAmount: AmountJson,
depositFeeLimit: AmountJson): CoinWithDenom[]|undefined {
if (cds.length === 0) {
return undefined;
}
// Sort by ascending deposit fee
cds.sort((o1, o2) => Amounts.cmp(o1.denom.feeDeposit,
o2.denom.feeDeposit));
const currency = cds[0].denom.value.currency;
const cdsResult: CoinWithDenom[] = [];
let accFee: AmountJson = Amounts.getZero(currency);
let accAmount: AmountJson = Amounts.getZero(currency);
let isBelowFee = false;
let coversAmount = false;
let coversAmountWithFee = false;
for (const {coin, denom} of cds) {
if (coin.suspended) {
continue;
}
if (coin.status !== CoinStatus.Fresh) {
continue;
}
if (Amounts.cmp(denom.feeDeposit, coin.currentAmount) >= 0) {
continue;
}
cdsResult.push({coin, denom});
accFee = Amounts.add(denom.feeDeposit, accFee).amount;
accAmount = Amounts.add(coin.currentAmount, accAmount).amount;
coversAmount = Amounts.cmp(accAmount, paymentAmount) >= 0;
coversAmountWithFee = Amounts.cmp(accAmount,
Amounts.add(paymentAmount,
denom.feeDeposit).amount) >= 0;
isBelowFee = Amounts.cmp(accFee, depositFeeLimit) <= 0;
if ((coversAmount && isBelowFee) || coversAmountWithFee) {
return cdsResult;
}
}
return undefined;
}
/**
* 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: DenominationRecord[]): DenominationRecord[] {
let remaining = Amounts.copy(amountAvailable);
const ds: DenominationRecord[] = [];
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 (const d of denoms) {
const cost = Amounts.add(d.value, d.feeWithdraw).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;
}
/* tslint:disable:completed-docs */
/**
* The stores and indices for the wallet database.
*/
export namespace Stores {
class ExchangeStore extends Store {
constructor() {
super("exchanges", {keyPath: "baseUrl"});
}
pubKeyIndex = new Index(this, "pubKey", "masterPublicKey");
}
class NonceStore extends Store {
constructor() {
super("nonces", {keyPath: "pub"});
}
}
class CoinsStore extends Store {
constructor() {
super("coins", {keyPath: "coinPub"});
}
exchangeBaseUrlIndex = new Index(this, "exchangeBaseUrl", "exchangeBaseUrl");
denomPubIndex = new Index(this, "denomPub", "denomPub");
}
class HistoryStore extends Store {
constructor() {
super("history", {
autoIncrement: true,
keyPath: "id",
});
}
timestampIndex = new Index(this, "timestamp", "timestamp");
}
class ProposalsStore extends Store {
constructor() {
super("proposals", {
autoIncrement: true,
keyPath: "id",
});
}
}
class PurchasesStore extends Store {
constructor() {
super("purchases", {keyPath: "contractTermsHash"});
}
fulfillmentUrlIndex = new Index(this, "fulfillment_url", "contractTerms.fulfillment_url");
orderIdIndex = new Index(this, "order_id", "contractTerms.order_id");
}
class DenominationsStore extends Store {
constructor() {
// cast needed because of bug in type annotations
super("denominations",
{keyPath: ["exchangeBaseUrl", "denomPub"] as any as IDBKeyPath});
}
denomPubHashIndex = new Index(this, "denomPubHash", "denomPubHash");
exchangeBaseUrlIndex = new Index(this, "exchangeBaseUrl", "exchangeBaseUrl");
denomPubIndex = new Index(this, "denomPub", "denomPub");
}
class CurrenciesStore extends Store {
constructor() {
super("currencies", {keyPath: "name"});
}
}
class ConfigStore extends Store {
constructor() {
super("config", {keyPath: "key"});
}
}
class ExchangeWireFeesStore extends Store {
constructor() {
super("exchangeWireFees", {keyPath: "exchangeBaseUrl"});
}
}
export const coins = new CoinsStore();
export const coinsReturns = new Store("coinsReturns", {keyPath: "contractTermsHash"});
export const config = new ConfigStore();
export const currencies = new CurrenciesStore();
export const denominations = new DenominationsStore();
export const exchangeWireFees = new ExchangeWireFeesStore();
export const exchanges = new ExchangeStore();
export const history = new HistoryStore();
export const nonces = new NonceStore();
export const precoins = new Store("precoins", {keyPath: "coinPub"});
export const proposals = new ProposalsStore();
export const refresh = new Store("refresh", {keyPath: "meltCoinPub"});
export const reserves = new Store("reserves", {keyPath: "reserve_pub"});
export const purchases = new PurchasesStore();
}
/* tslint:enable:completed-docs */
interface CoinsForPaymentArgs {
allowedAuditors: Auditor[];
allowedExchanges: ExchangeHandle[];
depositFeeLimit: AmountJson;
paymentAmount: AmountJson;
wireFeeAmortization: number;
wireFeeLimit: AmountJson;
wireFeeTime: number;
wireMethod: string;
}
/**
* The platform-independent wallet implementation.
*/
export class Wallet {
/**
* IndexedDB database used by the wallet.
*/
db: IDBDatabase;
private http: HttpRequestLibrary;
private badge: Badge;
private notifier: Notifier;
private cryptoApi: CryptoApi;
private processPreCoinConcurrent = 0;
private processPreCoinThrottle: {[url: string]: number} = {};
private timerGroup: TimerGroup;
/**
* Set of identifiers for running operations.
*/
private runningOperations: Set = new Set();
q(): QueryRoot {
return new QueryRoot(this.db);
}
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();
this.fillDefaults();
this.resumePendingFromDb();
this.timerGroup = new TimerGroup();
this.timerGroup.every(1000 * 60 * 15, () => this.updateExchanges());
}
private async fillDefaults() {
const onTrue = (r: QueryRoot) => {
console.log("defaults already applied");
};
const onFalse = (r: QueryRoot) => {
console.log("applying defaults");
r.put(Stores.config, {key: "currencyDefaultsApplied", value: true})
.putAll(Stores.currencies, builtinCurrencies)
.finish();
};
await (
this.q()
.iter(Stores.config)
.filter((x) => x.key === "currencyDefaultsApplied")
.first()
.cond((x) => x && x.value, onTrue, onFalse)
);
}
private startOperation(operationId: string) {
this.runningOperations.add(operationId);
this.badge.startBusy();
}
private stopOperation(operationId: string) {
this.runningOperations.delete(operationId);
if (this.runningOperations.size === 0) {
this.badge.stopBusy();
}
}
async updateExchanges(): Promise {
console.log("updating exchanges");
const exchangesUrls = await this.q()
.iter(Stores.exchanges)
.map((e) => e.baseUrl)
.toArray();
for (const url of exchangesUrls) {
this.updateExchangeFromUrl(url)
.catch((e) => {
console.error("updating exchange failed", e);
});
}
}
/**
* Resume various pending operations that are pending
* by looking at the database.
*/
private resumePendingFromDb(): void {
console.log("resuming pending operations from db");
this.q()
.iter(Stores.reserves)
.reduce((reserve) => {
console.log("resuming reserve", reserve.reserve_pub);
this.processReserve(reserve);
});
this.q()
.iter(Stores.precoins)
.reduce((preCoin) => {
console.log("resuming precoin");
this.processPreCoin(preCoin);
});
this.q()
.iter(Stores.refresh)
.reduce((r: RefreshSessionRecord) => {
this.continueRefreshSession(r);
});
this.q()
.iter(Stores.coinsReturns)
.reduce((r: CoinsReturnRecord) => {
this.depositReturnedCoins(r);
});
// FIXME: optimize via index
this.q()
.iter(Stores.coins)
.reduce((c: CoinRecord) => {
if (c.status === CoinStatus.Dirty) {
console.log("resuming pending refresh for coin", c);
this.refresh(c.coinPub);
}
});
}
private async getCoinsForReturn(exchangeBaseUrl: string, amount: AmountJson): Promise {
const exchange = await this.q().get(Stores.exchanges, exchangeBaseUrl);
if (!exchange) {
throw Error(`Exchange ${exchangeBaseUrl} not known to the wallet`);
}
const coins: CoinRecord[] = await (
this.q()
.iterIndex(Stores.coins.exchangeBaseUrlIndex, exchange.baseUrl)
.toArray()
);
if (!coins || !coins.length) {
return [];
}
// Denomination of the first coin, we assume that all other
// coins have the same currency
const firstDenom = await this.q().get(Stores.denominations,
[
exchange.baseUrl,
coins[0].denomPub,
]);
if (!firstDenom) {
throw Error("db inconsistent");
}
const currency = firstDenom.value.currency;
const cds: CoinWithDenom[] = [];
for (const coin of coins) {
const denom = await this.q().get(Stores.denominations,
[exchange.baseUrl, coin.denomPub]);
if (!denom) {
throw Error("db inconsistent");
}
if (denom.value.currency !== currency) {
console.warn(`same pubkey for different currencies at exchange ${exchange.baseUrl}`);
continue;
}
if (coin.suspended) {
continue;
}
if (coin.status !== CoinStatus.Fresh) {
continue;
}
cds.push({coin, denom});
}
return selectPayCoins(cds, amount, amount);
}
/**
* Get exchanges and associated coins that are still spendable,
* but only if the sum the coins' remaining value exceeds the payment amount.
*/
private async getCoinsForPayment(args: CoinsForPaymentArgs): Promise {
const {
allowedAuditors,
allowedExchanges,
depositFeeLimit,
paymentAmount,
wireFeeAmortization,
wireFeeLimit,
wireFeeTime,
wireMethod,
} = args;
let remainingAmount = paymentAmount;
const exchanges = await this.q().iter(Stores.exchanges).toArray();
for (const exchange of exchanges) {
let isOkay: boolean = false;
// is the exchange explicitly allowed?
for (const allowedExchange of allowedExchanges) {
if (allowedExchange.master_pub === exchange.masterPublicKey) {
isOkay = true;
break;
}
}
// is the exchange allowed because of one of its auditors?
if (!isOkay) {
for (const allowedAuditor of allowedAuditors) {
for (const auditor of exchange.auditors) {
if (auditor.auditor_pub === allowedAuditor.auditor_pub) {
isOkay = true;
break;
}
}
if (isOkay) {
break;
}
}
}
if (!isOkay) {
continue;
}
const coins: CoinRecord[] = await this.q()
.iterIndex(Stores.coins.exchangeBaseUrlIndex,
exchange.baseUrl)
.toArray();
if (!coins || coins.length === 0) {
continue;
}
// Denomination of the first coin, we assume that all other
// coins have the same currency
const firstDenom = await this.q().get(Stores.denominations,
[
exchange.baseUrl,
coins[0].denomPub,
]);
if (!firstDenom) {
throw Error("db inconsistent");
}
const currency = firstDenom.value.currency;
const cds: CoinWithDenom[] = [];
for (const coin of coins) {
const denom = await this.q().get(Stores.denominations,
[exchange.baseUrl, coin.denomPub]);
if (!denom) {
throw Error("db inconsistent");
}
if (denom.value.currency !== currency) {
console.warn(`same pubkey for different currencies at exchange ${exchange.baseUrl}`);
continue;
}
if (coin.suspended) {
continue;
}
if (coin.status !== CoinStatus.Fresh) {
continue;
}
cds.push({coin, denom});
}
const fees = await this.q().get(Stores.exchangeWireFees, exchange.baseUrl);
if (!fees) {
console.error("no fees found for exchange", exchange);
continue;
}
let wireFee: AmountJson|undefined;
for (const fee of (fees.feesForType[wireMethod] || [])) {
if (fee.startStamp >= wireFeeTime && fee.endStamp <= wireFeeTime) {
wireFee = fee.wireFee;
break;
}
}
if (wireFee) {
const amortizedWireFee = Amounts.divide(wireFee, wireFeeAmortization);
if (Amounts.cmp(wireFeeLimit, amortizedWireFee) < 0) {
remainingAmount = Amounts.add(amortizedWireFee, remainingAmount).amount;
}
}
const res = selectPayCoins(cds, remainingAmount, depositFeeLimit);
if (res) {
return {
cds: res,
exchangeUrl: exchange.baseUrl,
};
}
}
return undefined;
}
/**
* Record all information that is necessary to
* pay for a proposal in the wallet's database.
*/
private async recordConfirmPay(proposal: ProposalRecord,
payCoinInfo: PayCoinInfo,
chosenExchange: string): Promise {
const payReq: PayReq = {
coins: payCoinInfo.map((x) => x.sig),
exchange: chosenExchange,
merchant_pub: proposal.contractTerms.merchant_pub,
order_id: proposal.contractTerms.order_id,
};
const t: PurchaseRecord = {
contractTerms: proposal.contractTerms,
contractTermsHash: proposal.contractTermsHash,
finished: false,
merchantSig: proposal.merchantSig,
payReq,
refundsDone: {},
refundsPending: {},
};
const historyEntry: HistoryRecord = {
detail: {
amount: proposal.contractTerms.amount,
contractTermsHash: proposal.contractTermsHash,
fulfillmentUrl: proposal.contractTerms.fulfillment_url,
merchantName: proposal.contractTerms.merchant.name,
},
level: HistoryLevel.User,
subjectId: `contract-${proposal.contractTermsHash}`,
timestamp: (new Date()).getTime(),
type: "pay",
};
await this.q()
.put(Stores.purchases, t)
.put(Stores.history, historyEntry)
.putAll(Stores.coins, payCoinInfo.map((pci) => pci.updatedCoin))
.finish();
this.notifier.notify();
}
async putHistory(historyEntry: HistoryRecord): Promise {
await this.q().put(Stores.history, historyEntry).finish();
this.notifier.notify();
}
/**
* Save a proposal in the database and return an id for it to
* retrieve it later.
*/
async saveProposal(proposal: ProposalRecord): Promise {
const id = await this.q().putWithResult(Stores.proposals, proposal);
this.notifier.notify();
if (typeof id !== "number") {
throw Error("db schema wrong");
}
return id;
}
/**
* Add a contract to the wallet and sign coins,
* but do not send them yet.
*/
async confirmPay(proposalId: number): Promise {
console.log("executing confirmPay");
const proposal: ProposalRecord|undefined = await this.q().get(Stores.proposals, proposalId);
if (!proposal) {
throw Error(`proposal with id ${proposalId} not found`);
}
const purchase = await this.q().get(Stores.purchases, proposal.contractTermsHash);
if (purchase) {
// Already payed ...
return "paid";
}
const res = await this.getCoinsForPayment({
allowedAuditors: proposal.contractTerms.auditors,
allowedExchanges: proposal.contractTerms.exchanges,
depositFeeLimit: proposal.contractTerms.max_fee,
paymentAmount: proposal.contractTerms.amount,
wireFeeAmortization: proposal.contractTerms.wire_fee_amortization || 1,
wireFeeLimit: proposal.contractTerms.max_wire_fee || Amounts.getZero(proposal.contractTerms.amount.currency),
wireFeeTime: getTalerStampSec(proposal.contractTerms.timestamp) || 0,
wireMethod: proposal.contractTerms.wire_method,
});
console.log("max_fee", proposal.contractTerms.max_fee);
console.log("coin selection result", res);
if (!res) {
console.log("not confirming payment, insufficient coins");
return "insufficient-balance";
}
const {exchangeUrl, cds} = res;
const ds = await this.cryptoApi.signDeposit(proposal.contractTerms, cds);
await this.recordConfirmPay(proposal, ds, exchangeUrl);
return "paid";
}
/**
* Check if payment for an offer is possible, or if the offer has already
* been payed for.
*/
async checkPay(proposalId: number): Promise {
const proposal = await this.q().get(Stores.proposals, proposalId);
if (!proposal) {
throw Error(`proposal with id ${proposalId} not found`);
}
// First check if we already payed for it.
const purchase = await this.q().get(Stores.purchases, proposal.contractTermsHash);
if (purchase) {
return "paid";
}
// If not already payed, check if we could pay for it.
const res = await this.getCoinsForPayment({
allowedAuditors: proposal.contractTerms.auditors,
allowedExchanges: proposal.contractTerms.exchanges,
depositFeeLimit: proposal.contractTerms.max_fee,
paymentAmount: proposal.contractTerms.amount,
wireFeeAmortization: proposal.contractTerms.wire_fee_amortization || 1,
wireFeeLimit: proposal.contractTerms.max_wire_fee || Amounts.getZero(proposal.contractTerms.amount.currency),
wireFeeTime: getTalerStampSec(proposal.contractTerms.timestamp) || 0,
wireMethod: proposal.contractTerms.wire_method,
});
if (!res) {
console.log("not confirming payment, insufficient coins");
return "insufficient-balance";
}
return "payment-possible";
}
/**
* Retrieve information required to pay for a contract, where the
* contract is identified via the fulfillment url.
*/
async queryPayment(url: string): Promise {
console.log("query for payment", url);
const t = await this.q().getIndexed(Stores.purchases.fulfillmentUrlIndex, url);
if (!t) {
console.log("query for payment failed");
return {
found: false,
};
}
console.log("query for payment succeeded:", t);
return {
contractTermsHash: t.contractTermsHash,
contractTerms: t.contractTerms,
payReq: t.payReq,
found: true,
};
}
/**
* First fetch information requred to withdraw from the reserve,
* then deplete the reserve, withdrawing coins until it is empty.
*/
private async processReserve(reserveRecord: ReserveRecord,
retryDelayMs: number = 250): Promise {
const opId = "reserve-" + reserveRecord.reserve_pub;
this.startOperation(opId);
try {
const reserve = await this.updateReserve(reserveRecord.reserve_pub);
const n = await this.depleteReserve(reserve);
if (n !== 0) {
const depleted: HistoryRecord = {
detail: {
currentAmount: reserveRecord.current_amount,
exchangeBaseUrl: reserveRecord.exchange_base_url,
requestedAmount: reserveRecord.requested_amount,
reservePub: reserveRecord.reserve_pub,
},
level: HistoryLevel.User,
subjectId: `reserve-progress-${reserveRecord.reserve_pub}`,
timestamp: (new Date()).getTime(),
type: "depleted-reserve",
};
await this.q().put(Stores.history, depleted).finish();
}
} catch (e) {
// random, exponential backoff truncated at 3 minutes
const nextDelay = Math.min(2 * retryDelayMs + retryDelayMs * Math.random(), 3000 * 60);
console.warn(`Failed to deplete reserve, trying again in ${retryDelayMs} ms`);
this.timerGroup.after(retryDelayMs, () => this.processReserve(reserveRecord, nextDelay))
} finally {
this.stopOperation(opId);
}
}
private async processPreCoin(preCoin: PreCoinRecord,
retryDelayMs = 200): Promise {
if (this.processPreCoinConcurrent >= 4 || this.processPreCoinThrottle[preCoin.exchangeBaseUrl]) {
console.log("delaying processPreCoin");
this.timerGroup.after(retryDelayMs, () => this.processPreCoin(preCoin, Math.min(retryDelayMs * 2, 5 * 60 * 1000)));
return;
}
console.log("executing processPreCoin");
this.processPreCoinConcurrent++;
try {
const exchange = await this.q().get(Stores.exchanges,
preCoin.exchangeBaseUrl);
if (!exchange) {
console.error("db inconsistend: exchange for precoin not found");
return;
}
const denom = await this.q().get(Stores.denominations,
[preCoin.exchangeBaseUrl, preCoin.denomPub]);
if (!denom) {
console.error("db inconsistent: denom for precoin not found");
return;
}
const coin = await this.withdrawExecute(preCoin);
const mutateReserve = (r: ReserveRecord) => {
console.log(`before committing coin: current ${amountToPretty(r.current_amount!)}, precoin: ${amountToPretty(
r.precoin_amount)})}`);
const x = Amounts.sub(r.precoin_amount, preCoin.coinValue, denom.feeWithdraw);
if (x.saturated) {
console.error("database inconsistent");
throw AbortTransaction;
}
r.precoin_amount = x.amount;
return r;
};
const historyEntry: HistoryRecord = {
detail: {
coinPub: coin.coinPub,
},
level: HistoryLevel.Expert,
timestamp: (new Date()).getTime(),
type: "withdraw",
};
await this.q()
.mutate(Stores.reserves, preCoin.reservePub, mutateReserve)
.delete("precoins", coin.coinPub)
.add(Stores.coins, coin)
.add(Stores.history, historyEntry)
.finish();
this.notifier.notify();
} catch (e) {
console.error("Failed to withdraw coin from precoin, retrying in",
retryDelayMs,
"ms", e);
// exponential backoff truncated at one minute
const nextRetryDelayMs = Math.min(retryDelayMs * 2, 5 * 60 * 1000);
this.timerGroup.after(retryDelayMs, () => this.processPreCoin(preCoin, nextRetryDelayMs))
const currentThrottle = this.processPreCoinThrottle[preCoin.exchangeBaseUrl] || 0;
this.processPreCoinThrottle[preCoin.exchangeBaseUrl] = currentThrottle + 1;
this.timerGroup.after(retryDelayMs, () => {this.processPreCoinThrottle[preCoin.exchangeBaseUrl]--; });
} finally {
this.processPreCoinConcurrent--;
}
}
/**
* Create a reserve, but do not flag it as confirmed yet.
*
* Adds the corresponding exchange as a trusted exchange if it is neither
* audited nor trusted already.
*/
async createReserve(req: CreateReserveRequest): Promise {
const keypair = await this.cryptoApi.createEddsaKeypair();
const now = (new Date()).getTime();
const canonExchange = canonicalizeBaseUrl(req.exchange);
const reserveRecord: ReserveRecord = {
confirmed: false,
created: now,
current_amount: null,
exchange_base_url: canonExchange,
hasPayback: false,
last_query: null,
precoin_amount: Amounts.getZero(req.amount.currency),
requested_amount: req.amount,
reserve_priv: keypair.priv,
reserve_pub: keypair.pub,
senderWire: req.senderWire,
};
const historyEntry = {
detail: {
requestedAmount: req.amount,
reservePub: reserveRecord.reserve_pub,
},
level: HistoryLevel.Expert,
subjectId: `reserve-progress-${reserveRecord.reserve_pub}`,
timestamp: now,
type: "create-reserve",
};
const exchangeInfo = await this.updateExchangeFromUrl(req.exchange);
const {isAudited, isTrusted} = await this.getExchangeTrust(exchangeInfo);
let currencyRecord = await this.q().get(Stores.currencies, exchangeInfo.currency);
if (!currencyRecord) {
currencyRecord = {
auditors: [],
exchanges: [],
fractionalDigits: 2,
name: exchangeInfo.currency,
};
}
if (!isAudited && !isTrusted) {
currencyRecord.exchanges.push({baseUrl: req.exchange, exchangePub: exchangeInfo.masterPublicKey});
}
await this.q()
.put(Stores.currencies, currencyRecord)
.put(Stores.reserves, reserveRecord)
.put(Stores.history, historyEntry)
.finish();
const 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.
*/
async confirmReserve(req: ConfirmReserveRequest): Promise {
const now = (new Date()).getTime();
const reserve: ReserveRecord|undefined = await (
this.q().get(Stores.reserves,
req.reservePub));
if (!reserve) {
console.error("Unable to confirm reserve, not found in DB");
return;
}
console.log("reserve confirmed");
const historyEntry: HistoryRecord = {
detail: {
exchangeBaseUrl: reserve.exchange_base_url,
requestedAmount: reserve.requested_amount,
reservePub: req.reservePub,
},
level: HistoryLevel.User,
subjectId: `reserve-progress-${reserve.reserve_pub}`,
timestamp: now,
type: "confirm-reserve",
};
reserve.confirmed = true;
await this.q()
.put(Stores.reserves, reserve)
.put(Stores.history, historyEntry)
.finish();
this.notifier.notify();
this.processReserve(reserve);
}
private async withdrawExecute(pc: PreCoinRecord): Promise {
const reserve = await this.q().get(Stores.reserves,
pc.reservePub);
if (!reserve) {
throw Error("db inconsistent");
}
const wd: any = {};
wd.denom_pub = pc.denomPub;
wd.reserve_pub = pc.reservePub;
wd.reserve_sig = pc.withdrawSig;
wd.coin_ev = pc.coinEv;
const reqUrl = (new URI("reserve/withdraw")).absoluteTo(reserve.exchange_base_url);
const resp = await this.http.postJson(reqUrl.href(), wd);
if (resp.status !== 200) {
throw new RequestException({
hint: "Withdrawal failed",
status: resp.status,
});
}
const r = JSON.parse(resp.responseText);
const denomSig = await this.cryptoApi.rsaUnblind(r.ev_sig,
pc.blindingKey,
pc.denomPub);
const coin: CoinRecord = {
blindingKey: pc.blindingKey,
coinPriv: pc.coinPriv,
coinPub: pc.coinPub,
currentAmount: pc.coinValue,
denomPub: pc.denomPub,
denomSig,
exchangeBaseUrl: pc.exchangeBaseUrl,
reservePub: pc.reservePub,
status: CoinStatus.Fresh,
};
return coin;
}
/**
* Withdraw coins from a reserve until it is empty.
*/
private async depleteReserve(reserve: ReserveRecord): Promise {
console.log("depleting reserve");
if (!reserve.current_amount) {
throw Error("can't withdraw when amount is unknown");
}
const withdrawAmount = reserve.current_amount;
if (!withdrawAmount) {
throw Error("can't withdraw when amount is unknown");
}
const denomsForWithdraw = await this.getVerifiedWithdrawDenomList(reserve.exchange_base_url, withdrawAmount);
console.log(`withdrawing ${denomsForWithdraw.length} coins`);
const ps = denomsForWithdraw.map(async(denom) => {
function mutateReserve(r: ReserveRecord): ReserveRecord {
const currentAmount = r.current_amount;
if (!currentAmount) {
throw Error("can't withdraw when amount is unknown");
}
r.precoin_amount = Amounts.add(r.precoin_amount,
denom.value,
denom.feeWithdraw).amount;
const result = Amounts.sub(currentAmount,
denom.value,
denom.feeWithdraw);
if (result.saturated) {
console.error("can't create precoin, saturated");
throw AbortTransaction;
}
r.current_amount = result.amount;
console.log(`after creating precoin: current ${amountToPretty(r.current_amount)}, precoin: ${amountToPretty(
r.precoin_amount)})}`);
return r;
}
const preCoin = await this.cryptoApi
.createPreCoin(denom, reserve);
await this.q()
.put(Stores.precoins, preCoin)
.mutate(Stores.reserves, reserve.reserve_pub, mutateReserve);
await this.processPreCoin(preCoin);
});
await Promise.all(ps);
return ps.length;
}
/**
* Update the information about a reserve that is stored in the wallet
* by quering the reserve's exchange.
*/
private async updateReserve(reservePub: string): Promise {
const reserve = await this.q()
.get(Stores.reserves, reservePub);
if (!reserve) {
throw Error("reserve not in db");
}
const reqUrl = new URI("reserve/status").absoluteTo(reserve.exchange_base_url);
reqUrl.query({reserve_pub: reservePub});
const resp = await this.http.get(reqUrl.href());
if (resp.status !== 200) {
throw Error();
}
const reserveInfo = JSON.parse(resp.responseText);
if (!reserveInfo) {
throw Error();
}
const oldAmount = reserve.current_amount;
const newAmount = reserveInfo.balance;
reserve.current_amount = reserveInfo.balance;
const historyEntry = {
detail: {
newAmount,
oldAmount,
requestedAmount: reserve.requested_amount,
reservePub,
},
level: HistoryLevel.Developer,
subjectId: `reserve-progress-${reserve.reserve_pub}`,
timestamp: (new Date()).getTime(),
type: "reserve-update",
};
await this.q()
.put(Stores.reserves, reserve)
.put(Stores.history, historyEntry)
.finish();
this.notifier.notify();
return reserve;
}
/**
* Get the wire information for the exchange with the given base URL.
*/
async getWireInfo(exchangeBaseUrl: string): Promise {
exchangeBaseUrl = canonicalizeBaseUrl(exchangeBaseUrl);
const reqUrl = new URI("wire").absoluteTo(exchangeBaseUrl);
const resp = await this.http.get(reqUrl.href());
if (resp.status !== 200) {
throw Error("/wire request failed");
}
const wiJson = JSON.parse(resp.responseText);
if (!wiJson) {
throw Error("/wire response malformed");
}
return wiJson;
}
async getPossibleDenoms(exchangeBaseUrl: string) {
return (
this.q().iterIndex(Stores.denominations.exchangeBaseUrlIndex,
exchangeBaseUrl)
.filter((d) => d.status === DenominationStatus.Unverified || d.status === DenominationStatus.VerifiedGood)
.toArray()
);
}
/**
* Get a list of denominations to withdraw from the given exchange for the
* given amount, making sure that all denominations' signatures are verified.
*
* Writes to the DB in order to record the result from verifying
* denominations.
*/
async getVerifiedWithdrawDenomList(exchangeBaseUrl: string,
amount: AmountJson): Promise {
const exchange = await this.q().get(Stores.exchanges, exchangeBaseUrl);
if (!exchange) {
throw Error(`exchange ${exchangeBaseUrl} not found`);
}
const possibleDenoms = await (
this.q().iterIndex(Stores.denominations.exchangeBaseUrlIndex,
exchange.baseUrl)
.filter((d) => d.status === DenominationStatus.Unverified || d.status === DenominationStatus.VerifiedGood)
.toArray()
);
let allValid = false;
let currentPossibleDenoms = possibleDenoms;
let selectedDenoms: DenominationRecord[];
do {
allValid = true;
const nextPossibleDenoms = [];
selectedDenoms = getWithdrawDenomList(amount, possibleDenoms);
for (const denom of selectedDenoms || []) {
if (denom.status === DenominationStatus.Unverified) {
console.log(`verifying denom ${denom.denomPub.substr(0, 15)}`);
const valid = await this.cryptoApi.isValidDenom(denom,
exchange.masterPublicKey);
if (!valid) {
denom.status = DenominationStatus.VerifiedBad;
allValid = false;
} else {
denom.status = DenominationStatus.VerifiedGood;
nextPossibleDenoms.push(denom);
}
await this.q().put(Stores.denominations, denom).finish();
} else {
nextPossibleDenoms.push(denom);
}
}
currentPossibleDenoms = nextPossibleDenoms;
} while (selectedDenoms.length > 0 && !allValid);
return selectedDenoms;
}
/**
* Check if and how an exchange is trusted and/or audited.
*/
async getExchangeTrust(exchangeInfo: ExchangeRecord): Promise<{isTrusted: boolean, isAudited: boolean}> {
let isTrusted = false;
let isAudited = false;
const currencyRecord = await this.q().get(Stores.currencies, exchangeInfo.currency);
if (currencyRecord) {
for (const trustedExchange of currencyRecord.exchanges) {
if (trustedExchange.exchangePub === exchangeInfo.masterPublicKey) {
isTrusted = true;
break;
}
}
for (const trustedAuditor of currencyRecord.auditors) {
for (const exchangeAuditor of exchangeInfo.auditors) {
if (trustedAuditor.auditorPub === exchangeAuditor.auditor_pub) {
isAudited = true;
break;
}
}
}
}
return {isTrusted, isAudited};
}
async getReserveCreationInfo(baseUrl: string,
amount: AmountJson): Promise {
const exchangeInfo = await this.updateExchangeFromUrl(baseUrl);
const selectedDenoms = await this.getVerifiedWithdrawDenomList(baseUrl,
amount);
let acc = Amounts.getZero(amount.currency);
for (const d of selectedDenoms) {
acc = Amounts.add(acc, d.feeWithdraw).amount;
}
const actualCoinCost = selectedDenoms
.map((d: DenominationRecord) => Amounts.add(d.value,
d.feeWithdraw).amount)
.reduce((a, b) => Amounts.add(a, b).amount);
const wireInfo = await this.getWireInfo(baseUrl);
const wireFees = await this.q().get(Stores.exchangeWireFees, baseUrl);
if (!wireFees) {
// should never happen unless DB is inconsistent
throw Error(`no wire fees found for exchange ${baseUrl}`);
}
const {isTrusted, isAudited} = await this.getExchangeTrust(exchangeInfo);
let earliestDepositExpiration = Infinity;
for (const denom of selectedDenoms) {
const expireDeposit = getTalerStampSec(denom.stampExpireDeposit)!;
if (expireDeposit < earliestDepositExpiration) {
earliestDepositExpiration = expireDeposit;
}
}
const possibleDenoms = await (
this.q().iterIndex(Stores.denominations.exchangeBaseUrlIndex, baseUrl)
.filter((d) => d.isOffered)
.toArray()
) || [];
const trustedAuditorPubs = [];
const currencyRecord = await this.q().get(Stores.currencies, amount.currency);
if (currencyRecord) {
trustedAuditorPubs.push(...currencyRecord.auditors.map((a) => a.auditorPub));
}
let versionMatch;
if (exchangeInfo.protocolVersion) {
versionMatch = LibtoolVersion.compare(WALLET_PROTOCOL_VERSION, exchangeInfo.protocolVersion);
if (versionMatch && !versionMatch.compatible && versionMatch.currentCmp == -1) {
console.log("wallet version might be outdated, checking for updates");
chrome.runtime.requestUpdateCheck((status, details) => {
console.log("update check status:", status);
});
}
}
const ret: ReserveCreationInfo = {
earliestDepositExpiration,
exchangeInfo,
isAudited,
isTrusted,
numOfferedDenoms: possibleDenoms.length,
overhead: Amounts.sub(amount, actualCoinCost).amount,
selectedDenoms,
trustedAuditorPubs,
wireFees,
wireInfo,
withdrawFee: acc,
versionMatch,
};
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.
*/
async updateExchangeFromUrl(baseUrl: string): Promise {
baseUrl = canonicalizeBaseUrl(baseUrl);
const keysUrl = new URI("keys").absoluteTo(baseUrl);
const wireUrl = new URI("wire").absoluteTo(baseUrl);
const keysResp = await this.http.get(keysUrl.href());
if (keysResp.status !== 200) {
throw Error("/keys request failed");
}
const wireResp = await this.http.get(wireUrl.href());
if (wireResp.status !== 200) {
throw Error("/wire request failed");
}
const exchangeKeysJson = KeysJson.checked(JSON.parse(keysResp.responseText));
const wireRespJson = JSON.parse(wireResp.responseText);
if (typeof wireRespJson !== "object") {
throw Error("/wire response is not an object");
}
console.log("exchange wire", wireRespJson);
const wireMethodDetails: WireDetailJson[] = [];
for (const methodName in wireRespJson) {
wireMethodDetails.push(WireDetailJson.checked(wireRespJson[methodName]));
}
return this.updateExchangeFromJson(baseUrl, exchangeKeysJson, wireMethodDetails);
}
private async suspendCoins(exchangeInfo: ExchangeRecord): Promise {
const resultSuspendedCoins = await (
this.q()
.iterIndex(Stores.coins.exchangeBaseUrlIndex, exchangeInfo.baseUrl)
.indexJoinLeft(Stores.denominations.exchangeBaseUrlIndex,
(e) => e.exchangeBaseUrl)
.reduce((cd: JoinLeftResult,
suspendedCoins: CoinRecord[]) => {
if ((!cd.right) || (!cd.right.isOffered)) {
return Array.prototype.concat(suspendedCoins, [cd.left]);
}
return Array.prototype.concat(suspendedCoins);
}, []));
const q = this.q();
resultSuspendedCoins.map((c) => {
console.log("suspending coin", c);
c.suspended = true;
q.put(Stores.coins, c);
});
await q.finish();
}
private async updateExchangeFromJson(baseUrl: string,
exchangeKeysJson: KeysJson,
wireMethodDetails: WireDetailJson[]): Promise {
// FIXME: all this should probably be commited atomically
const updateTimeSec = getTalerStampSec(exchangeKeysJson.list_issue_date);
if (updateTimeSec === null) {
throw Error("invalid update time");
}
if (exchangeKeysJson.denoms.length === 0) {
throw Error("exchange doesn't offer any denominations");
}
const r = await this.q().get(Stores.exchanges, baseUrl);
let exchangeInfo: ExchangeRecord;
if (!r) {
exchangeInfo = {
auditors: exchangeKeysJson.auditors,
baseUrl,
currency: exchangeKeysJson.denoms[0].value.currency,
lastUpdateTime: updateTimeSec,
masterPublicKey: exchangeKeysJson.master_public_key,
};
console.log("making fresh exchange");
} else {
if (updateTimeSec < r.lastUpdateTime) {
console.log("outdated /keys, not updating");
return r;
}
exchangeInfo = r;
exchangeInfo.lastUpdateTime = updateTimeSec;
console.log("updating old exchange");
}
const updatedExchangeInfo = await this.updateExchangeInfo(exchangeInfo,
exchangeKeysJson);
await this.suspendCoins(updatedExchangeInfo);
updatedExchangeInfo.protocolVersion = exchangeKeysJson.version;
await this.q()
.put(Stores.exchanges, updatedExchangeInfo)
.finish();
let oldWireFees = await this.q().get(Stores.exchangeWireFees, baseUrl);
if (!oldWireFees) {
oldWireFees = {
exchangeBaseUrl: baseUrl,
feesForType: {},
};
}
for (const detail of wireMethodDetails) {
let latestFeeStamp = 0;
const fees = oldWireFees.feesForType[detail.type] || [];
oldWireFees.feesForType[detail.type] = fees;
for (const oldFee of fees) {
if (oldFee.endStamp > latestFeeStamp) {
latestFeeStamp = oldFee.endStamp;
}
}
for (const fee of detail.fees) {
const start = getTalerStampSec(fee.start_date);
if (start === null) {
console.error("invalid start stamp in fee", fee);
continue;
}
if (start < latestFeeStamp) {
continue;
}
const end = getTalerStampSec(fee.end_date);
if (end === null) {
console.error("invalid end stamp in fee", fee);
continue;
}
const wf: WireFee = {
closingFee: fee.closing_fee,
endStamp: end,
sig: fee.sig,
startStamp: start,
wireFee: fee.wire_fee,
};
const valid: boolean = await this.cryptoApi.isValidWireFee(detail.type, wf, exchangeInfo.masterPublicKey);
if (!valid) {
console.error("fee signature invalid", fee);
throw Error("fee signature invalid");
}
fees.push(wf);
}
}
await this.q().put(Stores.exchangeWireFees, oldWireFees);
if (exchangeKeysJson.payback) {
for (const payback of exchangeKeysJson.payback) {
const denom = await this.q().getIndexed(Stores.denominations.denomPubHashIndex, payback.h_denom_pub);
if (!denom) {
continue;
}
console.log(`cashing back denom`, denom);
const coins = await this.q().iterIndex(Stores.coins.denomPubIndex, denom.denomPub).toArray();
for (const coin of coins) {
this.payback(coin.coinPub);
}
}
}
return updatedExchangeInfo;
}
private async updateExchangeInfo(exchangeInfo: ExchangeRecord,
newKeys: KeysJson): Promise {
if (exchangeInfo.masterPublicKey !== newKeys.master_public_key) {
throw Error("public keys do not match");
}
const existingDenoms: {[denomPub: string]: DenominationRecord} = await (
this.q().iterIndex(Stores.denominations.exchangeBaseUrlIndex,
exchangeInfo.baseUrl)
.reduce((x: DenominationRecord,
acc: typeof existingDenoms) => (acc[x.denomPub] = x, acc),
{})
);
const newDenoms: typeof existingDenoms = {};
const newAndUnseenDenoms: typeof existingDenoms = {};
for (const d of newKeys.denoms) {
const dr = await this.denominationRecordFromKeys(exchangeInfo.baseUrl, d);
if (!(d.denom_pub in existingDenoms)) {
newAndUnseenDenoms[dr.denomPub] = dr;
}
newDenoms[dr.denomPub] = dr;
}
for (const oldDenomPub in existingDenoms) {
if (!(oldDenomPub in newDenoms)) {
const d = existingDenoms[oldDenomPub];
d.isOffered = false;
}
}
await this.q()
.putAll(Stores.denominations,
Object.keys(newAndUnseenDenoms).map((d) => newAndUnseenDenoms[d]))
.putAll(Stores.denominations,
Object.keys(existingDenoms).map((d) => existingDenoms[d]))
.finish();
return exchangeInfo;
}
/**
* Get detailed balance information, sliced by exchange and by currency.
*/
async getBalances(): Promise {
/**
* Add amount to a balance field, both for
* the slicing by exchange and currency.
*/
function addTo(balance: WalletBalance, field: keyof WalletBalanceEntry, amount: AmountJson, exchange: string): void {
const z = Amounts.getZero(amount.currency);
const balanceIdentity = {available: z, paybackAmount: z, pendingIncoming: z, pendingPayment: z};
let entryCurr = balance.byCurrency[amount.currency];
if (!entryCurr) {
balance.byCurrency[amount.currency] = entryCurr = { ...balanceIdentity };
}
let entryEx = balance.byExchange[exchange];
if (!entryEx) {
balance.byExchange[exchange] = entryEx = { ...balanceIdentity };
}
entryCurr[field] = Amounts.add(entryCurr[field], amount).amount;
entryEx[field] = Amounts.add(entryEx[field], amount).amount;
}
function collectBalances(c: CoinRecord, balance: WalletBalance) {
if (c.suspended) {
return balance;
}
if (!(c.status === CoinStatus.Dirty || c.status === CoinStatus.Fresh)) {
return balance;
}
console.log("collecting balance");
addTo(balance, "available", c.currentAmount, c.exchangeBaseUrl);
return balance;
}
function collectPendingWithdraw(r: ReserveRecord, balance: WalletBalance) {
if (!r.confirmed) {
return balance;
}
let amount = r.current_amount;
if (!amount) {
amount = r.requested_amount;
}
amount = Amounts.add(amount, r.precoin_amount).amount;
if (Amounts.cmp(smallestWithdraw[r.exchange_base_url], amount) < 0) {
addTo(balance, "pendingIncoming", amount, r.exchange_base_url);
}
return balance;
}
function collectPaybacks(r: ReserveRecord, balance: WalletBalance) {
if (!r.hasPayback) {
return balance;
}
if (Amounts.cmp(smallestWithdraw[r.exchange_base_url], r.current_amount!) < 0) {
addTo(balance, "paybackAmount", r.current_amount!, r.exchange_base_url);
}
return balance;
}
function collectPendingRefresh(r: RefreshSessionRecord,
balance: WalletBalance) {
// Don't count finished refreshes, since the refresh already resulted
// in coins being added to the wallet.
if (r.finished) {
return balance;
}
addTo(balance, "pendingIncoming", r.valueOutput, r.exchangeBaseUrl);
return balance;
}
function collectPayments(t: PurchaseRecord, balance: WalletBalance) {
if (t.finished) {
return balance;
}
addTo(balance, "pendingIncoming", t.contractTerms.amount, t.payReq.exchange);
return balance;
}
function collectSmallestWithdraw(e: JoinResult,
sw: any) {
let min = sw[e.left.baseUrl];
const v = Amounts.add(e.right.value, e.right.feeWithdraw).amount;
if (!min) {
min = v;
} else if (Amounts.cmp(v, min) < 0) {
min = v;
}
sw[e.left.baseUrl] = min;
return sw;
}
const balance = {
byExchange: {},
byCurrency: {},
};
// Mapping from exchange pub to smallest
// possible amount we can withdraw
let smallestWithdraw: {[baseUrl: string]: AmountJson} = {};
smallestWithdraw = await (this.q()
.iter(Stores.exchanges)
.indexJoin(Stores.denominations.exchangeBaseUrlIndex,
(x) => x.baseUrl)
.reduce(collectSmallestWithdraw, {}));
const tx = this.q();
tx.iter(Stores.coins)
.reduce(collectBalances, balance);
tx.iter(Stores.refresh)
.reduce(collectPendingRefresh, balance);
tx.iter(Stores.reserves)
.reduce(collectPendingWithdraw, balance);
tx.iter(Stores.reserves)
.reduce(collectPaybacks, balance);
tx.iter(Stores.purchases)
.reduce(collectPayments, balance);
await tx.finish();
return balance;
}
async createRefreshSession(oldCoinPub: string): Promise {
const coin = await this.q().get(Stores.coins, oldCoinPub);
if (!coin) {
throw Error("coin not found");
}
if (coin.currentAmount.value === 0 && coin.currentAmount.fraction === 0) {
return undefined;
}
const exchange = await this.updateExchangeFromUrl(coin.exchangeBaseUrl);
if (!exchange) {
throw Error("db inconsistent");
}
const oldDenom = await this.q().get(Stores.denominations,
[exchange.baseUrl, coin.denomPub]);
if (!oldDenom) {
throw Error("db inconsistent");
}
const availableDenoms: DenominationRecord[] = await (
this.q()
.iterIndex(Stores.denominations.exchangeBaseUrlIndex,
exchange.baseUrl)
.toArray()
);
const availableAmount = Amounts.sub(coin.currentAmount,
oldDenom.feeRefresh).amount;
const newCoinDenoms = getWithdrawDenomList(availableAmount,
availableDenoms);
console.log("refreshing coin", coin);
console.log("refreshing into", newCoinDenoms);
if (newCoinDenoms.length === 0) {
console.log(`not refreshing, available amount ${amountToPretty(availableAmount)} too small`);
return undefined;
}
const refreshSession: RefreshSessionRecord = await (
this.cryptoApi.createRefreshSession(exchange.baseUrl,
3,
coin,
newCoinDenoms,
oldDenom.feeRefresh));
function mutateCoin(c: CoinRecord): CoinRecord {
const r = Amounts.sub(c.currentAmount,
refreshSession.valueWithFee);
if (r.saturated) {
// Something else must have written the coin value
throw AbortTransaction;
}
c.currentAmount = r.amount;
c.status = CoinStatus.Refreshed;
return c;
}
// Store refresh session and subtract refreshed amount from
// coin in the same transaction.
await this.q()
.put(Stores.refresh, refreshSession)
.mutate(Stores.coins, coin.coinPub, mutateCoin)
.finish();
return refreshSession;
}
async refresh(oldCoinPub: string): Promise {
let refreshSession: RefreshSessionRecord|undefined;
const oldSession = await this.q().get(Stores.refresh, oldCoinPub);
if (oldSession) {
console.log("got old session for", oldCoinPub);
console.log(oldSession);
refreshSession = oldSession;
} else {
refreshSession = await this.createRefreshSession(oldCoinPub);
}
if (!refreshSession) {
// refreshing not necessary
console.log("not refreshing", oldCoinPub);
return;
}
this.continueRefreshSession(refreshSession);
}
async continueRefreshSession(refreshSession: RefreshSessionRecord) {
if (refreshSession.finished) {
return;
}
if (typeof refreshSession.norevealIndex !== "number") {
const coinPub = refreshSession.meltCoinPub;
await this.refreshMelt(refreshSession);
const r = await this.q().get(Stores.refresh, coinPub);
if (!r) {
throw Error("refresh session does not exist anymore");
}
refreshSession = r;
}
await this.refreshReveal(refreshSession);
}
async refreshMelt(refreshSession: RefreshSessionRecord): Promise {
if (refreshSession.norevealIndex !== undefined) {
console.error("won't melt again");
return;
}
const coin = await this.q().get(Stores.coins,
refreshSession.meltCoinPub);
if (!coin) {
console.error("can't melt coin, it does not exist");
return;
}
const reqUrl = new URI("refresh/melt").absoluteTo(refreshSession.exchangeBaseUrl);
const meltCoin = {
coin_pub: coin.coinPub,
confirm_sig: refreshSession.confirmSig,
denom_pub: coin.denomPub,
denom_sig: coin.denomSig,
value_with_fee: refreshSession.valueWithFee,
};
const coinEvs = refreshSession.preCoinsForGammas.map((x) => x.map((y) => y.coinEv));
const req = {
coin_evs: coinEvs,
melt_coin: meltCoin,
new_denoms: refreshSession.newDenoms,
transfer_pubs: refreshSession.transferPubs,
};
console.log("melt request:", req);
const resp = await this.http.postJson(reqUrl.href(), req);
console.log("melt request:", req);
console.log("melt response:", resp.responseText);
if (resp.status !== 200) {
console.error(resp.responseText);
throw Error("refresh failed");
}
const respJson = JSON.parse(resp.responseText);
if (!respJson) {
throw Error("exchange responded with garbage");
}
const norevealIndex = respJson.noreveal_index;
if (typeof norevealIndex !== "number") {
throw Error("invalid response");
}
refreshSession.norevealIndex = norevealIndex;
await this.q().put(Stores.refresh, refreshSession).finish();
}
async refreshReveal(refreshSession: RefreshSessionRecord): Promise {
const norevealIndex = refreshSession.norevealIndex;
if (norevealIndex === undefined) {
throw Error("can't reveal without melting first");
}
const privs = Array.from(refreshSession.transferPrivs);
privs.splice(norevealIndex, 1);
const req = {
session_hash: refreshSession.hash,
transfer_privs: privs,
};
const reqUrl = new URI("refresh/reveal") .absoluteTo(refreshSession.exchangeBaseUrl);
console.log("reveal request:", req);
const resp = await this.http.postJson(reqUrl.href(), req);
console.log("session:", refreshSession);
console.log("reveal response:", resp);
if (resp.status !== 200) {
console.log("error: /refresh/reveal returned status " + resp.status);
return;
}
const respJson = JSON.parse(resp.responseText);
if (!respJson.ev_sigs || !Array.isArray(respJson.ev_sigs)) {
console.log("/refresh/reveal did not contain ev_sigs");
}
const exchange = await this.q().get(Stores.exchanges,
refreshSession.exchangeBaseUrl);
if (!exchange) {
console.error(`exchange ${refreshSession.exchangeBaseUrl} not found`);
return;
}
const coins: CoinRecord[] = [];
for (let i = 0; i < respJson.ev_sigs.length; i++) {
const denom = await (
this.q()
.get(Stores.denominations,
[
refreshSession.exchangeBaseUrl,
refreshSession.newDenoms[i],
]));
if (!denom) {
console.error("denom not found");
continue;
}
const pc = refreshSession.preCoinsForGammas[refreshSession.norevealIndex!][i];
const denomSig = await this.cryptoApi.rsaUnblind(respJson.ev_sigs[i].ev_sig,
pc.blindingKey,
denom.denomPub);
const coin: CoinRecord = {
blindingKey: pc.blindingKey,
coinPriv: pc.privateKey,
coinPub: pc.publicKey,
currentAmount: denom.value,
denomPub: denom.denomPub,
denomSig,
exchangeBaseUrl: refreshSession.exchangeBaseUrl,
reservePub: undefined,
status: CoinStatus.Fresh,
};
coins.push(coin);
}
refreshSession.finished = true;
await this.q()
.putAll(Stores.coins, coins)
.put(Stores.refresh, refreshSession)
.finish();
}
/**
* Retrive the full event history for this wallet.
*/
async getHistory(): Promise<{history: HistoryRecord[]}> {
function collect(x: any, acc: any) {
acc.push(x);
return acc;
}
const history = await (
this.q()
.iterIndex(Stores.history.timestampIndex)
.reduce(collect, []));
return {history};
}
async getDenoms(exchangeUrl: string): Promise {
const denoms = await this.q().iterIndex(Stores.denominations.exchangeBaseUrlIndex, exchangeUrl).toArray();
return denoms;
}
async getProposal(proposalId: number): Promise {
const proposal = await this.q().get(Stores.proposals, proposalId);
return proposal;
}
async getExchanges(): Promise {
return this.q()
.iter(Stores.exchanges)
.toArray();
}
async getCurrencies(): Promise {
return this.q()
.iter(Stores.currencies)
.toArray();
}
async updateCurrency(currencyRecord: CurrencyRecord): Promise {
console.log("updating currency to", currencyRecord);
await this.q()
.put(Stores.currencies, currencyRecord)
.finish();
this.notifier.notify();
}
async getReserves(exchangeBaseUrl: string): Promise {
return this.q()
.iter(Stores.reserves)
.filter((r: ReserveRecord) => r.exchange_base_url === exchangeBaseUrl)
.toArray();
}
async getCoins(exchangeBaseUrl: string): Promise {
return this.q()
.iter(Stores.coins)
.filter((c: CoinRecord) => c.exchangeBaseUrl === exchangeBaseUrl)
.toArray();
}
async getPreCoins(exchangeBaseUrl: string): Promise {
return this.q()
.iter(Stores.precoins)
.filter((c: PreCoinRecord) => c.exchangeBaseUrl === exchangeBaseUrl)
.toArray();
}
async hashContract(contract: ContractTerms): Promise {
return this.cryptoApi.hashString(canonicalJson(contract));
}
/**
* Generate a nonce in form of an EdDSA public key.
* Store the private key in our DB, so we can prove ownership.
*/
async generateNonce(): Promise {
const {priv, pub} = await this.cryptoApi.createEddsaKeypair();
await this.q()
.put(Stores.nonces, {priv, pub})
.finish();
return pub;
}
async getCurrencyRecord(currency: string): Promise {
return this.q().get(Stores.currencies, currency);
}
async paymentSucceeded(contractTermsHash: string, merchantSig: string): Promise {
const doPaymentSucceeded = async() => {
const t = await this.q().get(Stores.purchases,
contractTermsHash);
if (!t) {
console.error("contract not found");
return;
}
const merchantPub = t.contractTerms.merchant_pub;
const valid = this.cryptoApi.isValidPaymentSignature(merchantSig, contractTermsHash, merchantPub);
if (!valid) {
console.error("merchant payment signature invalid");
// FIXME: properly display error
return;
}
t.finished = true;
const modifiedCoins: CoinRecord[] = [];
for (const pc of t.payReq.coins) {
const c = await this.q().get(Stores.coins, pc.coin_pub);
if (!c) {
console.error("coin not found");
return;
}
c.status = CoinStatus.Dirty;
modifiedCoins.push(c);
}
await this.q()
.putAll(Stores.coins, modifiedCoins)
.put(Stores.purchases, t)
.finish();
for (const c of t.payReq.coins) {
this.refresh(c.coin_pub);
}
};
doPaymentSucceeded();
return;
}
async payback(coinPub: string): Promise {
let coin = await this.q().get(Stores.coins, coinPub);
if (!coin) {
throw Error(`Coin ${coinPub} not found, can't request payback`);
}
const reservePub = coin.reservePub;
if (!reservePub) {
throw Error(`Can't request payback for a refreshed coin`);
}
const reserve = await this.q().get(Stores.reserves, reservePub);
if (!reserve) {
throw Error(`Reserve of coin ${coinPub} not found`);
}
switch (coin.status) {
case CoinStatus.Refreshed:
throw Error(`Can't do payback for coin ${coinPub} since it's refreshed`);
case CoinStatus.PaybackDone:
console.log(`Coin ${coinPub} already payed back`);
return;
}
coin.status = CoinStatus.PaybackPending;
// Even if we didn't get the payback yet, we suspend withdrawal, since
// technically we might update reserve status before we get the response
// from the reserve for the payback request.
reserve.hasPayback = true;
await this.q().put(Stores.coins, coin).put(Stores.reserves, reserve);
const paybackRequest = await this.cryptoApi.createPaybackRequest(coin);
const reqUrl = new URI("payback").absoluteTo(coin.exchangeBaseUrl);
const resp = await this.http.postJson(reqUrl.href(), paybackRequest);
if (resp.status !== 200) {
throw Error();
}
const paybackConfirmation = PaybackConfirmation.checked(JSON.parse(resp.responseText));
if (paybackConfirmation.reserve_pub !== coin.reservePub) {
throw Error(`Coin's reserve doesn't match reserve on payback`);
}
coin = await this.q().get(Stores.coins, coinPub);
if (!coin) {
throw Error(`Coin ${coinPub} not found, can't confirm payback`);
}
coin.status = CoinStatus.PaybackDone;
await this.q().put(Stores.coins, coin);
await this.updateReserve(reservePub!);
}
async denominationRecordFromKeys(exchangeBaseUrl: string, denomIn: Denomination): Promise {
const denomPubHash = await this.cryptoApi.hashDenomPub(denomIn.denom_pub);
const d: DenominationRecord = {
denomPub: denomIn.denom_pub,
denomPubHash,
exchangeBaseUrl,
feeDeposit: denomIn.fee_deposit,
feeRefresh: denomIn.fee_refresh,
feeRefund: denomIn.fee_refund,
feeWithdraw: denomIn.fee_withdraw,
isOffered: true,
masterSig: denomIn.master_sig,
stampExpireDeposit: denomIn.stamp_expire_deposit,
stampExpireLegal: denomIn.stamp_expire_legal,
stampExpireWithdraw: denomIn.stamp_expire_withdraw,
stampStart: denomIn.stamp_start,
status: DenominationStatus.Unverified,
value: denomIn.value,
};
return d;
}
async withdrawPaybackReserve(reservePub: string): Promise {
const reserve = await this.q().get(Stores.reserves, reservePub);
if (!reserve) {
throw Error(`Reserve ${reservePub} does not exist`);
}
reserve.hasPayback = false;
await this.q().put(Stores.reserves, reserve);
this.depleteReserve(reserve);
}
async getPaybackReserves(): Promise {
return await this.q().iter(Stores.reserves).filter((r) => r.hasPayback).toArray();
}
/**
* Stop ongoing processing.
*/
stop() {
this.timerGroup.stopCurrentAndFutureTimers();
}
async getSenderWireInfos(): Promise {
const m: { [url: string]: Set } = {};
await this.q().iter(Stores.exchangeWireFees).map((x) => {
const s = m[x.exchangeBaseUrl] = m[x.exchangeBaseUrl] || new Set();
Object.keys(x.feesForType).map((k) => s.add(k));
}).run();
console.log(m);
const exchangeWireTypes: { [url: string]: string[] } = {};
Object.keys(m).map((e) => { exchangeWireTypes[e] = Array.from(m[e]); });
const senderWiresSet = new Set();
await this.q().iter(Stores.reserves).map((x) => {
if (x.senderWire) {
senderWiresSet.add(JSON.stringify(x.senderWire));
}
}).run();
const senderWires = Array.from(senderWiresSet).map((x) => JSON.parse(x));
return {
exchangeWireTypes,
senderWires,
};
}
/**
* Trigger paying coins back into the user's account.
*/
async returnCoins(req: ReturnCoinsRequest): Promise {
console.log("got returnCoins request", req);
const wireType = (req.senderWire as any).type;
console.log("wireType", wireType);
if (!wireType || typeof wireType !== "string") {
console.error(`wire type must be a non-empty string, not ${wireType}`);
return;
}
const stampSecNow = Math.floor((new Date()).getTime() / 1000);
const exchange = await this.q().get(Stores.exchanges, req.exchange);
if (!exchange) {
console.error(`Exchange ${req.exchange} not known to the wallet`);
return;
}
const cds = await this.getCoinsForReturn(req.exchange, req.amount);
console.log(cds);
if (!cds) {
throw Error("coin return impossible, can't select coins");
}
const { priv, pub } = await this.cryptoApi.createEddsaKeypair();
const wireHash = await this.cryptoApi.hashString(canonicalJson(req.senderWire));
const contractTerms: ContractTerms = {
H_wire: wireHash,
amount: req.amount,
auditors: [],
wire_method: wireType,
pay_deadline: `/Date(${stampSecNow + 60 * 5})/`,
locations: [],
max_fee: req.amount,
merchant: {},
merchant_pub: pub,
exchanges: [ { master_pub: exchange.masterPublicKey, url: exchange.baseUrl } ],
products: [],
refund_deadline: `/Date(${stampSecNow + 60 * 5})/`,
timestamp: `/Date(${stampSecNow})/`,
order_id: "none",
pay_url: "",
fulfillment_url: "",
extra: {},
};
const contractTermsHash = await this.cryptoApi.hashString(canonicalJson(contractTerms));
const payCoinInfo = await this.cryptoApi.signDeposit(contractTerms, cds);
console.log("pci", payCoinInfo);
const coins = payCoinInfo.map((pci) => ({ coinPaySig: pci.sig }));
const coinsReturnRecord: CoinsReturnRecord = {
coins,
exchange: exchange.baseUrl,
contractTerms,
contractTermsHash,
merchantPriv: priv,
wire: req.senderWire,
}
await this.q()
.put(Stores.coinsReturns, coinsReturnRecord)
.putAll(Stores.coins, payCoinInfo.map((pci) => pci.updatedCoin))
.finish();
this.depositReturnedCoins(coinsReturnRecord);
}
async depositReturnedCoins(coinsReturnRecord: CoinsReturnRecord): Promise {
for (const c of coinsReturnRecord.coins) {
if (c.depositedSig) {
continue;
}
const req = {
f: c.coinPaySig.f,
wire: coinsReturnRecord.wire,
H_wire: coinsReturnRecord.contractTerms.H_wire,
h_contract_terms: coinsReturnRecord.contractTermsHash,
coin_pub: c.coinPaySig.coin_pub,
denom_pub: c.coinPaySig.denom_pub,
ub_sig: c.coinPaySig.ub_sig,
timestamp: coinsReturnRecord.contractTerms.timestamp,
wire_transfer_deadline: coinsReturnRecord.contractTerms.pay_deadline,
pay_deadline: coinsReturnRecord.contractTerms.pay_deadline,
refund_deadline: coinsReturnRecord.contractTerms.refund_deadline,
merchant_pub: coinsReturnRecord.contractTerms.merchant_pub,
coin_sig: c.coinPaySig.coin_sig,
};
console.log("req", req);
const reqUrl = (new URI("deposit")).absoluteTo(coinsReturnRecord.exchange);
const resp = await this.http.postJson(reqUrl.href(), req);
if (resp.status !== 200) {
console.error("deposit failed due to status code", resp);
continue;
}
const respJson = JSON.parse(resp.responseText);
if (respJson.status !== "DEPOSIT_OK") {
console.error("deposit failed", resp);
continue;
}
if (!respJson.sig) {
console.error("invalid 'sig' field", resp);
continue;
}
// FIXME: verify signature
// For every successful deposit, we replace the old record with an updated one
const currentCrr = await this.q().get(Stores.coinsReturns, coinsReturnRecord.contractTermsHash);
if (!currentCrr) {
console.error("database inconsistent");
continue;
}
for (const nc of currentCrr.coins) {
if (nc.coinPaySig.coin_pub === c.coinPaySig.coin_pub) {
nc.depositedSig = respJson.sig;
}
}
await this.q().put(Stores.coinsReturns, currentCrr);
}
}
async acceptRefund(refundPermissions: RefundPermission[]): Promise {
if (!refundPermissions.length) {
console.warn("got empty refund list");
return;
}
const hc = refundPermissions[0].h_contract_terms;
if (!hc) {
throw Error("h_contract_terms missing in refund permission");
}
const m = refundPermissions[0].merchant_pub;
if (!hc) {
throw Error("merchant_pub missing in refund permission");
}
for (const perm of refundPermissions) {
if (perm.h_contract_terms !== hc) {
throw Error("h_contract_terms different in refund permission");
}
if (perm.merchant_pub !== m) {
throw Error("merchant_pub different in refund permission");
}
}
/**
* Add refund to purchase if not already added.
*/
function f(t: PurchaseRecord|undefined): PurchaseRecord|undefined {
if (!t) {
console.error("purchase not found, not adding refunds");
return;
}
for (const perm of refundPermissions) {
if (!t.refundsPending[perm.merchant_sig] && !t.refundsDone[perm.merchant_sig]) {
t.refundsPending[perm.merchant_sig] = perm;
}
}
return t;
}
// Add the refund permissions to the purchase within a DB transaction
await this.q().mutate(Stores.purchases, hc, f).finish();
this.notifier.notify();
// Start submitting it but don't wait for it here.
this.submitRefunds(hc);
}
async submitRefunds(contractTermsHash: string): Promise {
const purchase = await this.q().get(Stores.purchases, contractTermsHash);
if (!purchase) {
console.error("not submitting refunds, contract terms not found:", contractTermsHash);
return;
}
const pendingKeys = Object.keys(purchase.refundsPending);
if (pendingKeys.length === 0) {
return;
}
for (const pk of pendingKeys) {
const perm = purchase.refundsPending[pk];
console.log("sending refund permission", perm);
const reqUrl = (new URI("refund")).absoluteTo(purchase.payReq.exchange);
const resp = await this.http.postJson(reqUrl.href(), perm);
if (resp.status !== 200) {
console.error("refund failed", resp);
continue;
}
// Transactionally mark successful refunds as done
const transformPurchase = (t: PurchaseRecord|undefined): PurchaseRecord|undefined => {
if (!t) {
console.warn("purchase not found, not updating refund");
return;
}
if (t.refundsPending[pk]) {
t.refundsDone[pk] = t.refundsPending[pk];
delete t.refundsPending[pk];
}
return t;
};
const transformCoin = (c: CoinRecord|undefined): CoinRecord|undefined => {
if (!c) {
console.warn("coin not found, can't apply refund");
return;
}
c.status = CoinStatus.Dirty;
c.currentAmount = Amounts.add(c.currentAmount, perm.refund_amount).amount;
c.currentAmount = Amounts.sub(c.currentAmount, perm.refund_fee).amount;
return c;
};
await this.q()
.mutate(Stores.purchases, contractTermsHash, transformPurchase)
.mutate(Stores.coins, perm.coin_pub, transformCoin)
.finish();
this.refresh(perm.coin_pub);
}
this.notifier.notify();
}
async getPurchase(contractTermsHash: string): Promise {
return this.q().get(Stores.purchases, contractTermsHash);
}
}