/api/mek/register, /api/mek/share Endpoint 삭제 및 MEK 서명 매커니즘 구현

2025년 첫 커밋! Happy New Year~

src/lib/server/modules/mek.ts

@@ -1,6 +1,25 @@
+import { error } from "@sveltejs/kit";
+import { getUserClientWithDetails } from "$lib/server/db/client";
 import { getInitialMek } from "$lib/server/db/mek";
+import { verifySignature } from "$lib/server/modules/crypto";
 
 export const isInitialMekNeeded = async (userId: number) => {
   const initialMek = await getInitialMek(userId);
   return !initialMek;
 };
+
+export const verifyClientEncMekSig = async (
+  userId: number,
+  clientId: number,
+  version: number,
+  encMek: string,
+  encMekSig: string,
+) => {
+  const userClient = await getUserClientWithDetails(userId, clientId);
+  if (!userClient) {
+    error(500, "Invalid access token");
+  }
+
+  const data = JSON.stringify({ version, key: encMek });
+  return verifySignature(Buffer.from(data), encMekSig, userClient.client.sigPubKey);
+};