From 0f13f2b238c7d7409e0cc49e83d732accaa4204d Mon Sep 17 00:00:00 2001
From: Tony Garnock-Jones <tonyg@leastfixedpoint.com>
Date: Tue, 19 Mar 2024 20:35:54 +0100
Subject: [PATCH] Reset noise state when server retracts and reasserts session

---
 packages/ws-relay/src/index.ts | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/packages/ws-relay/src/index.ts b/packages/ws-relay/src/index.ts
index e16df3e..2ba2485 100644
--- a/packages/ws-relay/src/index.ts
+++ b/packages/ws-relay/src/index.ts
@@ -247,16 +247,7 @@ export function boot(ds = Dataspace.global, debug: boolean = false, WebSocketCon
                     (() => { throw new Error("Invalid pre-shared keys"); })();
                 const prologue = underlying(canonicalEncode(spec.service));
 
-                const H = new SaltyCrypto.Handshake(
-                    algorithms,
-                    patternName,
-                    'initiator',
-                    {
-                        prologue,
-                        remoteStaticPublicKey: underlying(spec.key),
-                        preSharedKeys: preSharedKeys.map(underlying),
-                    });
-
+                let H: SaltyCrypto.Handshake | null = null;
                 let transportState: SaltyCrypto.TransportState | null = null;
                 let responderSession: Ref | null = null;
                 let relay: Relay.Relay | null = null;
@@ -306,6 +297,16 @@ export function boot(ds = Dataspace.global, debug: boolean = false, WebSocketCon
                                     if (!response) return;
                                     switch (response._variant) {
                                         case "accepted":
+                                            H = new SaltyCrypto.Handshake(
+                                                algorithms,
+                                                patternName,
+                                                'initiator',
+                                                {
+                                                    prologue,
+                                                    remoteStaticPublicKey: underlying(spec.key),
+                                                    preSharedKeys: preSharedKeys.map(underlying),
+                                                });
+                                            transportState = null;
                                             responderSession = response.responderSession;
                                             const { packet, finished } = H.writeMessage(new Uint8Array());
                                             at responderSession {
@@ -340,7 +341,7 @@ export function boot(ds = Dataspace.global, debug: boolean = false, WebSocketCon
                                         if (p._variant !== 'complete') {
                                             throw new Error("Unexpected fragmentation in handshake");
                                         }
-                                        const { message, finished } = H.readMessage(underlying(p.value));
+                                        const { message, finished } = H!.readMessage(underlying(p.value));
                                         if (message.byteLength !== 0) {
                                             throw new Error("Unexpected payload during handshake");
                                         }