/* This file is part of GNU Taler (C) 2022 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 */ /** * Imports. */ import { AbsoluteTime, AcceptPeerPullPaymentRequest, AcceptPeerPushPaymentRequest, AmountJson, AmountLike, Amounts, AmountString, buildCodecForObject, CheckPeerPullPaymentRequest, CheckPeerPullPaymentResponse, CheckPeerPushPaymentRequest, CheckPeerPushPaymentResponse, Codec, codecForAmountString, codecForAny, codecForExchangeGetContractResponse, CoinPublicKey, constructPayPullUri, constructPayPushUri, ContractTermsUtil, decodeCrock, Duration, eddsaGetPublic, encodeCrock, ExchangePurseDeposits, ExchangePurseMergeRequest, ExchangeReservePurseRequest, getRandomBytes, InitiatePeerPullPaymentRequest, InitiatePeerPullPaymentResponse, InitiatePeerPushPaymentRequest, InitiatePeerPushPaymentResponse, j2s, Logger, parsePayPullUri, parsePayPushUri, RefreshReason, strcmp, TalerProtocolTimestamp, UnblindedSignature, WalletAccountMergeFlags, } from "@gnu-taler/taler-util"; import { CoinStatus, MergeReserveInfo, ReserveRecordStatus, WalletStoresV1, } from "../db.js"; import { readSuccessResponseJsonOrThrow } from "../util/http.js"; import { InternalWalletState } from "../internal-wallet-state.js"; import { checkDbInvariant } from "../util/invariants.js"; import { internalCreateWithdrawalGroup } from "./withdraw.js"; import { GetReadOnlyAccess } from "../util/query.js"; import { createRefreshGroup } from "./refresh.js"; import { updateExchangeFromUrl } from "./exchanges.js"; const logger = new Logger("operations/peer-to-peer.ts"); export interface PeerCoinSelection { exchangeBaseUrl: string; /** * Info of Coins that were selected. */ coins: { coinPub: string; coinPriv: string; contribution: AmountString; denomPubHash: string; denomSig: UnblindedSignature; }[]; /** * How much of the deposit fees is the customer paying? */ depositFees: AmountJson; } interface CoinInfo { /** * Public key of the coin. */ coinPub: string; coinPriv: string; /** * Deposit fee for the coin. */ feeDeposit: AmountJson; value: AmountJson; denomPubHash: string; denomSig: UnblindedSignature; } export async function selectPeerCoins( ws: InternalWalletState, tx: GetReadOnlyAccess<{ exchanges: typeof WalletStoresV1.exchanges; denominations: typeof WalletStoresV1.denominations; coins: typeof WalletStoresV1.coins; }>, instructedAmount: AmountJson, ): Promise { const exchanges = await tx.exchanges.iter().toArray(); for (const exch of exchanges) { if (exch.detailsPointer?.currency !== instructedAmount.currency) { continue; } const coins = ( await tx.coins.indexes.byBaseUrl.getAll(exch.baseUrl) ).filter((x) => x.status === CoinStatus.Fresh); const coinInfos: CoinInfo[] = []; for (const coin of coins) { const denom = await ws.getDenomInfo( ws, tx, coin.exchangeBaseUrl, coin.denomPubHash, ); if (!denom) { throw Error("denom not found"); } coinInfos.push({ coinPub: coin.coinPub, feeDeposit: denom.feeDeposit, value: denom.value, denomPubHash: denom.denomPubHash, coinPriv: coin.coinPriv, denomSig: coin.denomSig, }); } if (coinInfos.length === 0) { continue; } coinInfos.sort( (o1, o2) => -Amounts.cmp(o1.value, o2.value) || strcmp(o1.denomPubHash, o2.denomPubHash), ); let amountAcc = Amounts.getZero(instructedAmount.currency); let depositFeesAcc = Amounts.getZero(instructedAmount.currency); const resCoins: { coinPub: string; coinPriv: string; contribution: AmountString; denomPubHash: string; denomSig: UnblindedSignature; }[] = []; for (const coin of coinInfos) { if (Amounts.cmp(amountAcc, instructedAmount) >= 0) { const res: PeerCoinSelection = { exchangeBaseUrl: exch.baseUrl, coins: resCoins, depositFees: depositFeesAcc, }; return res; } const gap = Amounts.add( coin.feeDeposit, Amounts.sub(instructedAmount, amountAcc).amount, ).amount; const contrib = Amounts.min(gap, coin.value); amountAcc = Amounts.add( amountAcc, Amounts.sub(contrib, coin.feeDeposit).amount, ).amount; depositFeesAcc = Amounts.add(depositFeesAcc, coin.feeDeposit).amount; resCoins.push({ coinPriv: coin.coinPriv, coinPub: coin.coinPub, contribution: Amounts.stringify(contrib), denomPubHash: coin.denomPubHash, denomSig: coin.denomSig, }); } continue; } return undefined; } export async function initiatePeerToPeerPush( ws: InternalWalletState, req: InitiatePeerPushPaymentRequest, ): Promise { // FIXME: actually create a record for retries here! const instructedAmount = Amounts.parseOrThrow(req.amount); const coinSelRes: PeerCoinSelection | undefined = await ws.db .mktx((x) => ({ exchanges: x.exchanges, coins: x.coins, denominations: x.denominations, refreshGroups: x.refreshGroups, })) .runReadWrite(async (tx) => { const sel = await selectPeerCoins(ws, tx, instructedAmount); if (!sel) { return undefined; } const pubs: CoinPublicKey[] = []; for (const c of sel.coins) { const coin = await tx.coins.get(c.coinPub); checkDbInvariant(!!coin); coin.currentAmount = Amounts.sub( coin.currentAmount, Amounts.parseOrThrow(c.contribution), ).amount; await tx.coins.put(coin); } await createRefreshGroup(ws, tx, pubs, RefreshReason.Pay); return sel; }); logger.info(`selected p2p coins: ${j2s(coinSelRes)}`); if (!coinSelRes) { throw Error("insufficient balance"); } const pursePair = await ws.cryptoApi.createEddsaKeypair({}); const mergePair = await ws.cryptoApi.createEddsaKeypair({}); const purseExpiration: TalerProtocolTimestamp = AbsoluteTime.toTimestamp( AbsoluteTime.addDuration( AbsoluteTime.now(), Duration.fromSpec({ days: 2 }), ), ); const contractTerms = { ...req.partialContractTerms, purse_expiration: purseExpiration, amount: req.amount, }; const hContractTerms = ContractTermsUtil.hashContractTerms(contractTerms); const purseSigResp = await ws.cryptoApi.signPurseCreation({ hContractTerms, mergePub: mergePair.pub, minAge: 0, purseAmount: Amounts.stringify(instructedAmount), purseExpiration, pursePriv: pursePair.priv, }); const depositSigsResp = await ws.cryptoApi.signPurseDeposits({ exchangeBaseUrl: coinSelRes.exchangeBaseUrl, pursePub: pursePair.pub, coins: coinSelRes.coins, }); const createPurseUrl = new URL( `purses/${pursePair.pub}/create`, coinSelRes.exchangeBaseUrl, ); const econtractResp = await ws.cryptoApi.encryptContractForMerge({ contractTerms, mergePriv: mergePair.priv, pursePriv: pursePair.priv, pursePub: pursePair.pub, }); const httpResp = await ws.http.postJson(createPurseUrl.href, { amount: Amounts.stringify(instructedAmount), merge_pub: mergePair.pub, purse_sig: purseSigResp.sig, h_contract_terms: hContractTerms, purse_expiration: purseExpiration, deposits: depositSigsResp.deposits, min_age: 0, econtract: econtractResp.econtract, }); const resp = await httpResp.json(); logger.info(`resp: ${j2s(resp)}`); if (httpResp.status !== 200) { throw Error("got error response from exchange"); } return { contractPriv: econtractResp.contractPriv, mergePriv: mergePair.priv, pursePub: pursePair.pub, exchangeBaseUrl: coinSelRes.exchangeBaseUrl, talerUri: constructPayPushUri({ exchangeBaseUrl: coinSelRes.exchangeBaseUrl, contractPriv: econtractResp.contractPriv, }), }; } interface ExchangePurseStatus { balance: AmountString; } export const codecForExchangePurseStatus = (): Codec => buildCodecForObject() .property("balance", codecForAmountString()) .build("ExchangePurseStatus"); export async function checkPeerPushPayment( ws: InternalWalletState, req: CheckPeerPushPaymentRequest, ): Promise { // FIXME: Check if existing record exists! const uri = parsePayPushUri(req.talerUri); if (!uri) { throw Error("got invalid taler://pay-push URI"); } const exchangeBaseUrl = uri.exchangeBaseUrl; await updateExchangeFromUrl(ws, exchangeBaseUrl); const contractPriv = uri.contractPriv; const contractPub = encodeCrock(eddsaGetPublic(decodeCrock(contractPriv))); const getContractUrl = new URL(`contracts/${contractPub}`, exchangeBaseUrl); const contractHttpResp = await ws.http.get(getContractUrl.href); const contractResp = await readSuccessResponseJsonOrThrow( contractHttpResp, codecForExchangeGetContractResponse(), ); const pursePub = contractResp.purse_pub; const dec = await ws.cryptoApi.decryptContractForMerge({ ciphertext: contractResp.econtract, contractPriv: contractPriv, pursePub: pursePub, }); const getPurseUrl = new URL(`purses/${pursePub}/deposit`, exchangeBaseUrl); const purseHttpResp = await ws.http.get(getPurseUrl.href); const purseStatus = await readSuccessResponseJsonOrThrow( purseHttpResp, codecForExchangePurseStatus(), ); const peerPushPaymentIncomingId = encodeCrock(getRandomBytes(32)); await ws.db .mktx((x) => ({ peerPushPaymentIncoming: x.peerPushPaymentIncoming, })) .runReadWrite(async (tx) => { await tx.peerPushPaymentIncoming.add({ peerPushPaymentIncomingId, contractPriv: contractPriv, exchangeBaseUrl: exchangeBaseUrl, mergePriv: dec.mergePriv, pursePub: pursePub, timestamp: TalerProtocolTimestamp.now(), contractTerms: dec.contractTerms, }); }); return { amount: purseStatus.balance, contractTerms: dec.contractTerms, peerPushPaymentIncomingId, }; } export function talerPaytoFromExchangeReserve( exchangeBaseUrl: string, reservePub: string, ): string { const url = new URL(exchangeBaseUrl); let proto: string; if (url.protocol === "http:") { proto = "taler-reserve-http"; } else if (url.protocol === "https:") { proto = "taler-reserve"; } else { throw Error(`unsupported exchange base URL protocol (${url.protocol})`); } let path = url.pathname; if (!path.endsWith("/")) { path = path + "/"; } return `payto://${proto}/${url.host}${url.pathname}${reservePub}`; } async function getMergeReserveInfo( ws: InternalWalletState, req: { exchangeBaseUrl: string; }, ): Promise { // We have to eagerly create the key pair outside of the transaction, // due to the async crypto API. const newReservePair = await ws.cryptoApi.createEddsaKeypair({}); const mergeReserveInfo: MergeReserveInfo = await ws.db .mktx((x) => ({ exchanges: x.exchanges, withdrawalGroups: x.withdrawalGroups, })) .runReadWrite(async (tx) => { const ex = await tx.exchanges.get(req.exchangeBaseUrl); checkDbInvariant(!!ex); if (ex.currentMergeReserveInfo) { return ex.currentMergeReserveInfo; } await tx.exchanges.put(ex); ex.currentMergeReserveInfo = { reservePriv: newReservePair.priv, reservePub: newReservePair.pub, }; return ex.currentMergeReserveInfo; }); return mergeReserveInfo; } export async function acceptPeerPushPayment( ws: InternalWalletState, req: AcceptPeerPushPaymentRequest, ) { const peerInc = await ws.db .mktx((x) => ({ peerPushPaymentIncoming: x.peerPushPaymentIncoming })) .runReadOnly(async (tx) => { return tx.peerPushPaymentIncoming.get(req.peerPushPaymentIncomingId); }); if (!peerInc) { throw Error( `can't accept unknown incoming p2p push payment (${req.peerPushPaymentIncomingId})`, ); } await updateExchangeFromUrl(ws, peerInc.exchangeBaseUrl); const amount = Amounts.parseOrThrow(peerInc.contractTerms.amount); const mergeReserveInfo = await getMergeReserveInfo(ws, { exchangeBaseUrl: peerInc.exchangeBaseUrl, }); const mergeTimestamp = TalerProtocolTimestamp.now(); const reservePayto = talerPaytoFromExchangeReserve( peerInc.exchangeBaseUrl, mergeReserveInfo.reservePub, ); const sigRes = await ws.cryptoApi.signPurseMerge({ contractTermsHash: ContractTermsUtil.hashContractTerms( peerInc.contractTerms, ), flags: WalletAccountMergeFlags.MergeFullyPaidPurse, mergePriv: peerInc.mergePriv, mergeTimestamp: mergeTimestamp, purseAmount: Amounts.stringify(amount), purseExpiration: peerInc.contractTerms.purse_expiration, purseFee: Amounts.stringify(Amounts.getZero(amount.currency)), pursePub: peerInc.pursePub, reservePayto, reservePriv: mergeReserveInfo.reservePriv, }); const mergePurseUrl = new URL( `purses/${peerInc.pursePub}/merge`, peerInc.exchangeBaseUrl, ); const mergeReq: ExchangePurseMergeRequest = { payto_uri: reservePayto, merge_timestamp: mergeTimestamp, merge_sig: sigRes.mergeSig, reserve_sig: sigRes.accountSig, }; const mergeHttpReq = await ws.http.postJson(mergePurseUrl.href, mergeReq); logger.info(`merge request: ${j2s(mergeReq)}`); const res = await readSuccessResponseJsonOrThrow(mergeHttpReq, codecForAny()); logger.info(`merge response: ${j2s(res)}`); await internalCreateWithdrawalGroup(ws, { amount, exchangeBaseUrl: peerInc.exchangeBaseUrl, reserveStatus: ReserveRecordStatus.QueryingStatus, reserveKeyPair: { priv: mergeReserveInfo.reservePriv, pub: mergeReserveInfo.reservePub, }, }); } /** * FIXME: Bad name! */ export async function acceptPeerPullPayment( ws: InternalWalletState, req: AcceptPeerPullPaymentRequest, ) { const peerPullInc = await ws.db .mktx((x) => ({ peerPullPaymentIncoming: x.peerPullPaymentIncoming })) .runReadOnly(async (tx) => { return tx.peerPullPaymentIncoming.get(req.peerPullPaymentIncomingId); }); if (!peerPullInc) { throw Error( `can't accept unknown incoming p2p pull payment (${req.peerPullPaymentIncomingId})`, ); } const instructedAmount = Amounts.parseOrThrow( peerPullInc.contractTerms.amount, ); const coinSelRes: PeerCoinSelection | undefined = await ws.db .mktx((x) => ({ exchanges: x.exchanges, coins: x.coins, denominations: x.denominations, refreshGroups: x.refreshGroups, })) .runReadWrite(async (tx) => { const sel = await selectPeerCoins(ws, tx, instructedAmount); if (!sel) { return undefined; } const pubs: CoinPublicKey[] = []; for (const c of sel.coins) { const coin = await tx.coins.get(c.coinPub); checkDbInvariant(!!coin); coin.currentAmount = Amounts.sub( coin.currentAmount, Amounts.parseOrThrow(c.contribution), ).amount; await tx.coins.put(coin); } await createRefreshGroup(ws, tx, pubs, RefreshReason.Pay); return sel; }); logger.info(`selected p2p coins: ${j2s(coinSelRes)}`); if (!coinSelRes) { throw Error("insufficient balance"); } const pursePub = peerPullInc.pursePub; const depositSigsResp = await ws.cryptoApi.signPurseDeposits({ exchangeBaseUrl: coinSelRes.exchangeBaseUrl, pursePub, coins: coinSelRes.coins, }); const purseDepositUrl = new URL( `purses/${pursePub}/deposit`, coinSelRes.exchangeBaseUrl, ); const depositPayload: ExchangePurseDeposits = { deposits: depositSigsResp.deposits, }; const httpResp = await ws.http.postJson(purseDepositUrl.href, depositPayload); const resp = await readSuccessResponseJsonOrThrow(httpResp, codecForAny()); logger.trace(`purse deposit response: ${j2s(resp)}`); } export async function checkPeerPullPayment( ws: InternalWalletState, req: CheckPeerPullPaymentRequest, ): Promise { const uri = parsePayPullUri(req.talerUri); if (!uri) { throw Error("got invalid taler://pay-push URI"); } const exchangeBaseUrl = uri.exchangeBaseUrl; const contractPriv = uri.contractPriv; const contractPub = encodeCrock(eddsaGetPublic(decodeCrock(contractPriv))); const getContractUrl = new URL(`contracts/${contractPub}`, exchangeBaseUrl); const contractHttpResp = await ws.http.get(getContractUrl.href); const contractResp = await readSuccessResponseJsonOrThrow( contractHttpResp, codecForExchangeGetContractResponse(), ); const pursePub = contractResp.purse_pub; const dec = await ws.cryptoApi.decryptContractForDeposit({ ciphertext: contractResp.econtract, contractPriv: contractPriv, pursePub: pursePub, }); const getPurseUrl = new URL(`purses/${pursePub}/merge`, exchangeBaseUrl); const purseHttpResp = await ws.http.get(getPurseUrl.href); const purseStatus = await readSuccessResponseJsonOrThrow( purseHttpResp, codecForExchangePurseStatus(), ); const peerPullPaymentIncomingId = encodeCrock(getRandomBytes(32)); await ws.db .mktx((x) => ({ peerPullPaymentIncoming: x.peerPullPaymentIncoming, })) .runReadWrite(async (tx) => { await tx.peerPullPaymentIncoming.add({ peerPullPaymentIncomingId, contractPriv: contractPriv, exchangeBaseUrl: exchangeBaseUrl, pursePub: pursePub, timestamp: TalerProtocolTimestamp.now(), contractTerms: dec.contractTerms, }); }); return { amount: purseStatus.balance, contractTerms: dec.contractTerms, peerPullPaymentIncomingId, }; } export async function initiatePeerRequestForPay( ws: InternalWalletState, req: InitiatePeerPullPaymentRequest, ): Promise { const mergeReserveInfo = await getMergeReserveInfo(ws, { exchangeBaseUrl: req.exchangeBaseUrl, }); const mergeTimestamp = TalerProtocolTimestamp.now(); const pursePair = await ws.cryptoApi.createEddsaKeypair({}); const mergePair = await ws.cryptoApi.createEddsaKeypair({}); const purseExpiration: TalerProtocolTimestamp = AbsoluteTime.toTimestamp( AbsoluteTime.addDuration( AbsoluteTime.now(), Duration.fromSpec({ days: 2 }), ), ); const reservePayto = talerPaytoFromExchangeReserve( req.exchangeBaseUrl, mergeReserveInfo.reservePub, ); const contractTerms = { ...req.partialContractTerms, amount: req.amount, purse_expiration: purseExpiration, }; const econtractResp = await ws.cryptoApi.encryptContractForDeposit({ contractTerms, pursePriv: pursePair.priv, pursePub: pursePair.pub, }); const hContractTerms = ContractTermsUtil.hashContractTerms(contractTerms); const purseFee = Amounts.stringify( Amounts.getZero(Amounts.parseOrThrow(req.amount).currency), ); const sigRes = await ws.cryptoApi.signReservePurseCreate({ contractTermsHash: hContractTerms, flags: WalletAccountMergeFlags.CreateWithPurseFee, mergePriv: mergePair.priv, mergeTimestamp: mergeTimestamp, purseAmount: req.amount, purseExpiration: purseExpiration, purseFee: purseFee, pursePriv: pursePair.priv, pursePub: pursePair.pub, reservePayto, reservePriv: mergeReserveInfo.reservePriv, }); await ws.db .mktx((x) => ({ peerPullPaymentInitiation: x.peerPullPaymentInitiation, })) .runReadWrite(async (tx) => { await tx.peerPullPaymentInitiation.put({ amount: req.amount, contractTerms, exchangeBaseUrl: req.exchangeBaseUrl, pursePriv: pursePair.priv, pursePub: pursePair.pub, }); }); const reservePurseReqBody: ExchangeReservePurseRequest = { merge_sig: sigRes.mergeSig, merge_timestamp: mergeTimestamp, h_contract_terms: hContractTerms, merge_pub: mergePair.pub, min_age: 0, purse_expiration: purseExpiration, purse_fee: purseFee, purse_pub: pursePair.pub, purse_sig: sigRes.purseSig, purse_value: req.amount, reserve_sig: sigRes.accountSig, econtract: econtractResp.econtract, }; logger.info(`reserve purse request: ${j2s(reservePurseReqBody)}`); const reservePurseMergeUrl = new URL( `reserves/${mergeReserveInfo.reservePub}/purse`, req.exchangeBaseUrl, ); const httpResp = await ws.http.postJson( reservePurseMergeUrl.href, reservePurseReqBody, ); const resp = await readSuccessResponseJsonOrThrow(httpResp, codecForAny()); logger.info(`reserve merge response: ${j2s(resp)}`); await internalCreateWithdrawalGroup(ws, { amount: Amounts.parseOrThrow(req.amount), exchangeBaseUrl: req.exchangeBaseUrl, reserveStatus: ReserveRecordStatus.QueryingStatus, reserveKeyPair: { priv: mergeReserveInfo.reservePriv, pub: mergeReserveInfo.reservePub, }, }); return { talerUri: constructPayPullUri({ exchangeBaseUrl: req.exchangeBaseUrl, contractPriv: econtractResp.contractPriv, }), }; }