From 7c76a3d2bf38cd2e39289be583cb6d27f508973b Mon Sep 17 00:00:00 2001
From: Offer Markovich <offerm@PayKey.com>
Date: Sat, 29 Jun 2019 19:03:07 +0300
Subject: [PATCH] feat(swaps): prevent raiden from being first leg

This prevents Raiden based currencies from being the first leg of
a swap. It better calculates the maker CLTV by using a cltv-delta of
5760 for raiden. This is the first step towards a more robust approach.

Co-authored-by: Daniel McNally <mcnallydp@gmail.com>
---
 lib/http/HttpService.ts          |  1 +
 lib/raidenclient/RaidenClient.ts |  5 +++--
 lib/swaps/SwapClientManager.ts   |  4 ++--
 lib/swaps/Swaps.ts               | 32 +++++++++++++++++++++++++++++---
 4 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/lib/http/HttpService.ts b/lib/http/HttpService.ts
index bf204b790..75dc00b53 100644
--- a/lib/http/HttpService.ts
+++ b/lib/http/HttpService.ts
@@ -5,6 +5,7 @@ class HttpService {
   constructor(private service: Service) {}
 
   public resolveHashRaiden = async (resolveRequest: RaidenResolveRequest): Promise<RaidenResolveResponse> => {
+    // TODO: add reveal_timeout, settle time out,  token, etc
     const secret = await this.service.resolveHash({
       rHash: resolveRequest.secrethash.slice(2),
       amount: resolveRequest.amount,
diff --git a/lib/raidenclient/RaidenClient.ts b/lib/raidenclient/RaidenClient.ts
index f4ab6ca23..b63933a9e 100644
--- a/lib/raidenclient/RaidenClient.ts
+++ b/lib/raidenclient/RaidenClient.ts
@@ -33,7 +33,7 @@ async function parseResponseBody<T>(res: http.IncomingMessage): Promise<T> {
  */
 class RaidenClient extends SwapClient {
   public readonly type = SwapClientType.Raiden;
-  public readonly cltvDelta: number = 1;
+  public readonly cltvDelta: number = 5760;
   public address?: string;
   /** A map of currency symbols to token addresses. */
   public tokenAddresses = new Map<string, string>();
@@ -151,8 +151,9 @@ class RaidenClient extends SwapClient {
 
   public getRoutes =  async (_amount: number, _destination: string) => {
     // stub placeholder, query routes not currently implemented in raiden
+    // assume a fixed lock time of 100 Raiden's blocks
     return [{
-      getTotalTimeLock: () => 1,
+      getTotalTimeLock: () => 101,
     }];
   }
 
diff --git a/lib/swaps/SwapClientManager.ts b/lib/swaps/SwapClientManager.ts
index ca2cf5680..1f31daa39 100644
--- a/lib/swaps/SwapClientManager.ts
+++ b/lib/swaps/SwapClientManager.ts
@@ -10,11 +10,11 @@ import { Models } from '../db/DB';
 import { SwapClientType } from '../constants/enums';
 import { EventEmitter } from 'events';
 
-function isRaidenClient(swapClient: SwapClient): swapClient is RaidenClient {
+export function isRaidenClient(swapClient: SwapClient): swapClient is RaidenClient {
   return (swapClient.type === SwapClientType.Raiden);
 }
 
-function isLndClient(swapClient: SwapClient): swapClient is LndClient {
+export function isLndClient(swapClient: SwapClient): swapClient is LndClient {
   return (swapClient.type === SwapClientType.Lnd);
 }
 
diff --git a/lib/swaps/Swaps.ts b/lib/swaps/Swaps.ts
index 3cc74b5b9..c54aee6d7 100644
--- a/lib/swaps/Swaps.ts
+++ b/lib/swaps/Swaps.ts
@@ -12,7 +12,7 @@ import { SwapDealInstance } from '../db/types';
 import { SwapDeal, SwapSuccess, SanitySwap, ResolveRequest } from './types';
 import { generatePreimageAndHash, setTimeoutPromise } from '../utils/utils';
 import { PacketType } from '../p2p/packets';
-import SwapClientManager from './SwapClientManager';
+import SwapClientManager, { isRaidenClient } from './SwapClientManager';
 import { errors } from './errors';
 
 export type OrderToAccept = Pick<SwapDeal, 'quantity' | 'price' | 'localId' | 'isBuy'> & {
@@ -433,6 +433,29 @@ class Swaps extends EventEmitter {
 
     const { makerCurrency, makerAmount, takerCurrency, takerAmount } = Swaps.calculateMakerTakerAmounts(quantity, price, isBuy, requestBody.pairId);
 
+    const makerSwapClient = this.swapClientManager.get(makerCurrency)!;
+    if (!makerSwapClient) {
+      await this.sendErrorToPeer({
+        peer,
+        rHash,
+        failureReason: SwapFailureReason.SwapClientNotSetup,
+        errorMessage: 'Unsupported maker currency',
+        reqId: requestPacket.header.id,
+      });
+      return false;
+    }
+
+    if (isRaidenClient(makerSwapClient)) {
+      await this.sendErrorToPeer({
+        peer,
+        rHash,
+        failureReason: SwapFailureReason.InvalidSwapRequest,
+        errorMessage: 'Raiden based tokens can not be first leg',
+        reqId: requestPacket.header.id,
+      });
+      return false;
+    }
+
     const takerSwapClient = this.swapClientManager.get(takerCurrency);
     if (!takerSwapClient) {
       await this.sendErrorToPeer({
@@ -558,7 +581,6 @@ class Swaps extends EventEmitter {
       return false;
     }
 
-    const makerSwapClient = this.swapClientManager.get(makerCurrency)!;
     try {
       await makerSwapClient.addInvoice(deal.rHash, deal.makerAmount, deal.makerCltvDelta);
     } catch (err) {
@@ -681,12 +703,16 @@ class Swaps extends EventEmitter {
     let expectedAmount: number;
     let source: string;
     let destination: string;
-
+    // TODO: check cltv value
     switch (deal.role) {
       case SwapRole.Maker:
         expectedAmount = deal.makerAmount;
         source = 'Taker';
         destination = 'Maker';
+        if (deal.makerCltvDelta! > 50 * 2) {
+          this.failDeal(deal, SwapFailureReason.InvalidResolveRequest, 'Wrong CLTV received on first leg');
+          return false;
+        }
         break;
       case SwapRole.Taker:
         expectedAmount = deal.takerAmount;