From f1155d26bfb37112df8903d8e8194182a286a927 Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Thu, 29 Jul 2021 14:39:12 +0100
Subject: [PATCH] Allocate the map

---
 keyserver/internal/cross_signing.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/keyserver/internal/cross_signing.go b/keyserver/internal/cross_signing.go
index 4aff9bb9..40715b67 100644
--- a/keyserver/internal/cross_signing.go
+++ b/keyserver/internal/cross_signing.go
@@ -195,6 +195,9 @@ func (a *KeyInternalAPI) crossSigningKeys(
 			}
 
 			appendSignature := func(originUserID string, originKeyID gomatrixserverlib.KeyID, signature gomatrixserverlib.Base64Bytes) {
+				if key.Signatures == nil {
+					key.Signatures = api.CrossSigningSigMap{}
+				}
 				if _, ok := key.Signatures[originUserID]; !ok {
 					key.Signatures[originUserID] = make(map[gomatrixserverlib.KeyID]gomatrixserverlib.Base64Bytes)
 				}