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/*
This file is part of GNU Taler
(C) 2019 GNUnet e.V.
GNU 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.
GNU 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
GNU Taler; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
import { InternalWalletState } from "./state";
import { WALLET_CACHE_BREAKER_CLIENT_VERSION } from "../wallet";
import {
KeysJson,
Denomination,
ExchangeWireJson,
} from "../talerTypes";
import { getTimestampNow, OperationError } from "../walletTypes";
import {
ExchangeRecord,
ExchangeUpdateStatus,
Stores,
DenominationRecord,
DenominationStatus,
WireFee,
} from "../dbTypes";
import {
canonicalizeBaseUrl,
extractTalerStamp,
extractTalerStampOrThrow,
} from "../util/helpers";
import {
oneShotGet,
oneShotPut,
runWithWriteTransaction,
oneShotMutate,
} from "../util/query";
import * as Amounts from "../util/amounts";
import { parsePaytoUri } from "../util/payto";
import {
OperationFailedAndReportedError,
guardOperationException,
} from "./errors";
async function denominationRecordFromKeys(
ws: InternalWalletState,
exchangeBaseUrl: string,
denomIn: Denomination,
): Promise<DenominationRecord> {
const denomPubHash = await ws.cryptoApi.hashDenomPub(denomIn.denom_pub);
const d: DenominationRecord = {
denomPub: denomIn.denom_pub,
denomPubHash,
exchangeBaseUrl,
feeDeposit: Amounts.parseOrThrow(denomIn.fee_deposit),
feeRefresh: Amounts.parseOrThrow(denomIn.fee_refresh),
feeRefund: Amounts.parseOrThrow(denomIn.fee_refund),
feeWithdraw: Amounts.parseOrThrow(denomIn.fee_withdraw),
isOffered: true,
masterSig: denomIn.master_sig,
stampExpireDeposit: extractTalerStampOrThrow(denomIn.stamp_expire_deposit),
stampExpireLegal: extractTalerStampOrThrow(denomIn.stamp_expire_legal),
stampExpireWithdraw: extractTalerStampOrThrow(
denomIn.stamp_expire_withdraw,
),
stampStart: extractTalerStampOrThrow(denomIn.stamp_start),
status: DenominationStatus.Unverified,
value: Amounts.parseOrThrow(denomIn.value),
};
return d;
}
async function setExchangeError(
ws: InternalWalletState,
baseUrl: string,
err: OperationError,
): Promise<void> {
const mut = (exchange: ExchangeRecord) => {
exchange.lastError = err;
return exchange;
};
await oneShotMutate(ws.db, Stores.exchanges, baseUrl, mut);
}
/**
* Fetch the exchange's /keys and update our database accordingly.
*
* Exceptions thrown in this method must be caught and reported
* in the pending operations.
*/
async function updateExchangeWithKeys(
ws: InternalWalletState,
baseUrl: string,
): Promise<void> {
const existingExchangeRecord = await oneShotGet(
ws.db,
Stores.exchanges,
baseUrl,
);
if (existingExchangeRecord?.updateStatus != ExchangeUpdateStatus.FETCH_KEYS) {
return;
}
const keysUrl = new URL("keys", baseUrl);
keysUrl.searchParams.set("cacheBreaker", WALLET_CACHE_BREAKER_CLIENT_VERSION);
let keysResp;
try {
keysResp = await ws.http.get(keysUrl.href);
} catch (e) {
const m = `Fetching keys failed: ${e.message}`;
await setExchangeError(ws, baseUrl, {
type: "network",
details: {
requestUrl: e.config?.url,
},
message: m,
});
throw new OperationFailedAndReportedError(m);
}
let exchangeKeysJson: KeysJson;
try {
exchangeKeysJson = KeysJson.checked(keysResp.responseJson);
} catch (e) {
const m = `Parsing /keys response failed: ${e.message}`;
await setExchangeError(ws, baseUrl, {
type: "protocol-violation",
details: {},
message: m,
});
throw new OperationFailedAndReportedError(m);
}
const lastUpdateTimestamp = extractTalerStamp(
exchangeKeysJson.list_issue_date,
);
if (!lastUpdateTimestamp) {
const m = `Parsing /keys response failed: invalid list_issue_date.`;
await setExchangeError(ws, baseUrl, {
type: "protocol-violation",
details: {},
message: m,
});
throw new OperationFailedAndReportedError(m);
}
if (exchangeKeysJson.denoms.length === 0) {
const m = "exchange doesn't offer any denominations";
await setExchangeError(ws, baseUrl, {
type: "protocol-violation",
details: {},
message: m,
});
throw new OperationFailedAndReportedError(m);
}
const protocolVersion = exchangeKeysJson.version;
if (!protocolVersion) {
const m = "outdate exchange, no version in /keys response";
await setExchangeError(ws, baseUrl, {
type: "protocol-violation",
details: {},
message: m,
});
throw new OperationFailedAndReportedError(m);
}
const currency = Amounts.parseOrThrow(exchangeKeysJson.denoms[0].value)
.currency;
const newDenominations = await Promise.all(
exchangeKeysJson.denoms.map(d =>
denominationRecordFromKeys(ws, baseUrl, d),
),
);
await runWithWriteTransaction(
ws.db,
[Stores.exchanges, Stores.denominations],
async tx => {
const r = await tx.get(Stores.exchanges, baseUrl);
if (!r) {
console.warn(`exchange ${baseUrl} no longer present`);
return;
}
if (r.details) {
// FIXME: We need to do some consistency checks!
}
r.details = {
auditors: exchangeKeysJson.auditors,
currency: currency,
lastUpdateTime: lastUpdateTimestamp,
masterPublicKey: exchangeKeysJson.master_public_key,
protocolVersion: protocolVersion,
};
r.updateStatus = ExchangeUpdateStatus.FETCH_WIRE;
r.lastError = undefined;
await tx.put(Stores.exchanges, r);
for (const newDenom of newDenominations) {
const oldDenom = await tx.get(Stores.denominations, [
baseUrl,
newDenom.denomPub,
]);
if (oldDenom) {
// FIXME: Do consistency check
} else {
await tx.put(Stores.denominations, newDenom);
}
}
},
);
}
/**
* Fetch wire information for an exchange and store it in the database.
*
* @param exchangeBaseUrl Exchange base URL, assumed to be already normalized.
*/
async function updateExchangeWithWireInfo(
ws: InternalWalletState,
exchangeBaseUrl: string,
) {
const exchange = await oneShotGet(ws.db, Stores.exchanges, exchangeBaseUrl);
if (!exchange) {
return;
}
if (exchange.updateStatus != ExchangeUpdateStatus.FETCH_WIRE) {
return;
}
const details = exchange.details;
if (!details) {
throw Error("invalid exchange state");
}
const reqUrl = new URL("wire", exchangeBaseUrl);
reqUrl.searchParams.set("cacheBreaker", WALLET_CACHE_BREAKER_CLIENT_VERSION);
const resp = await ws.http.get(reqUrl.href);
const wiJson = resp.responseJson;
if (!wiJson) {
throw Error("/wire response malformed");
}
const wireInfo = ExchangeWireJson.checked(wiJson);
for (const a of wireInfo.accounts) {
console.log("validating exchange acct");
const isValid = await ws.cryptoApi.isValidWireAccount(
a.url,
a.master_sig,
details.masterPublicKey,
);
if (!isValid) {
throw Error("exchange acct signature invalid");
}
}
const feesForType: { [wireMethod: string]: WireFee[] } = {};
for (const wireMethod of Object.keys(wireInfo.fees)) {
const feeList: WireFee[] = [];
for (const x of wireInfo.fees[wireMethod]) {
const startStamp = extractTalerStamp(x.start_date);
if (!startStamp) {
throw Error("wrong date format");
}
const endStamp = extractTalerStamp(x.end_date);
if (!endStamp) {
throw Error("wrong date format");
}
const fee: WireFee = {
closingFee: Amounts.parseOrThrow(x.closing_fee),
endStamp,
sig: x.sig,
startStamp,
wireFee: Amounts.parseOrThrow(x.wire_fee),
};
const isValid = await ws.cryptoApi.isValidWireFee(
wireMethod,
fee,
details.masterPublicKey,
);
if (!isValid) {
throw Error("exchange wire fee signature invalid");
}
feeList.push(fee);
}
feesForType[wireMethod] = feeList;
}
await runWithWriteTransaction(ws.db, [Stores.exchanges], async tx => {
const r = await tx.get(Stores.exchanges, exchangeBaseUrl);
if (!r) {
return;
}
if (r.updateStatus != ExchangeUpdateStatus.FETCH_WIRE) {
return;
}
r.wireInfo = {
accounts: wireInfo.accounts,
feesForType: feesForType,
};
r.updateStatus = ExchangeUpdateStatus.FINISHED;
r.lastError = undefined;
await tx.put(Stores.exchanges, r);
});
}
export async function updateExchangeFromUrl(
ws: InternalWalletState,
baseUrl: string,
forceNow: boolean = false,
): Promise<ExchangeRecord> {
const onOpErr = (e: OperationError) => setExchangeError(ws, baseUrl, e);
return await guardOperationException(
() => updateExchangeFromUrlImpl(ws, baseUrl, forceNow),
onOpErr,
);
}
/**
* Update or add exchange DB entry by fetching the /keys and /wire information.
* Optionally link the reserve entry to the new or existing
* exchange entry in then DB.
*/
async function updateExchangeFromUrlImpl(
ws: InternalWalletState,
baseUrl: string,
forceNow: boolean = false,
): Promise<ExchangeRecord> {
const now = getTimestampNow();
baseUrl = canonicalizeBaseUrl(baseUrl);
const r = await oneShotGet(ws.db, Stores.exchanges, baseUrl);
if (!r) {
const newExchangeRecord: ExchangeRecord = {
baseUrl: baseUrl,
details: undefined,
wireInfo: undefined,
updateStatus: ExchangeUpdateStatus.FETCH_KEYS,
updateStarted: now,
updateReason: "initial",
timestampAdded: getTimestampNow(),
};
await oneShotPut(ws.db, Stores.exchanges, newExchangeRecord);
} else {
await runWithWriteTransaction(ws.db, [Stores.exchanges], async t => {
const rec = await t.get(Stores.exchanges, baseUrl);
if (!rec) {
return;
}
if (rec.updateStatus != ExchangeUpdateStatus.FETCH_KEYS && !forceNow) {
return;
}
if (rec.updateStatus != ExchangeUpdateStatus.FETCH_KEYS && forceNow) {
rec.updateReason = "forced";
}
rec.updateStarted = now;
rec.updateStatus = ExchangeUpdateStatus.FETCH_KEYS;
rec.lastError = undefined;
t.put(Stores.exchanges, rec);
});
}
await updateExchangeWithKeys(ws, baseUrl);
await updateExchangeWithWireInfo(ws, baseUrl);
const updatedExchange = await oneShotGet(ws.db, Stores.exchanges, baseUrl);
if (!updatedExchange) {
// This should practically never happen
throw Error("exchange not found");
}
return updatedExchange;
}
/**
* Check if and how an exchange is trusted and/or audited.
*/
export async function getExchangeTrust(
ws: InternalWalletState,
exchangeInfo: ExchangeRecord,
): Promise<{ isTrusted: boolean; isAudited: boolean }> {
let isTrusted = false;
let isAudited = false;
const exchangeDetails = exchangeInfo.details;
if (!exchangeDetails) {
throw Error(`exchange ${exchangeInfo.baseUrl} details not available`);
}
const currencyRecord = await oneShotGet(
ws.db,
Stores.currencies,
exchangeDetails.currency,
);
if (currencyRecord) {
for (const trustedExchange of currencyRecord.exchanges) {
if (trustedExchange.exchangePub === exchangeDetails.masterPublicKey) {
isTrusted = true;
break;
}
}
for (const trustedAuditor of currencyRecord.auditors) {
for (const exchangeAuditor of exchangeDetails.auditors) {
if (trustedAuditor.auditorPub === exchangeAuditor.auditor_pub) {
isAudited = true;
break;
}
}
}
}
return { isTrusted, isAudited };
}
export async function getExchangePaytoUri(
ws: InternalWalletState,
exchangeBaseUrl: string,
supportedTargetTypes: string[],
): Promise<string> {
// We do the update here, since the exchange might not even exist
// yet in our database.
const exchangeRecord = await updateExchangeFromUrl(ws, exchangeBaseUrl);
if (!exchangeRecord) {
throw Error(`Exchange '${exchangeBaseUrl}' not found.`);
}
const exchangeWireInfo = exchangeRecord.wireInfo;
if (!exchangeWireInfo) {
throw Error(`Exchange wire info for '${exchangeBaseUrl}' not found.`);
}
for (let account of exchangeWireInfo.accounts) {
const res = parsePaytoUri(account.url);
if (!res) {
continue;
}
if (supportedTargetTypes.includes(res.targetType)) {
return account.url;
}
}
throw Error("no matching exchange account found");
}
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