Code-based authorization for Drop clients (#145)

* feat: code-based authorization

* fix: final touches

* fix: require session on code fetch endpoint

* feat: better error handling

* refactor: move auth send to client handler

* fix: lint

server/api/v1/client/auth/code/index.post.ts

@@ -0,0 +1,35 @@
+import clientHandler from "~/server/internal/clients/handler";
+import sessionHandler from "~/server/internal/session";
+
+export default defineEventHandler(async (h3) => {
+  const user = await sessionHandler.getSession(h3);
+  if (!user) throw createError({ statusCode: 403 });
+
+  const body = await readBody(h3);
+  const clientId = await body.id;
+
+  const client = await clientHandler.fetchClient(clientId);
+  if (!client)
+    throw createError({
+      statusCode: 400,
+      statusMessage: "Invalid or expired client ID.",
+    });
+
+  if (client.userId != user.userId)
+    throw createError({
+      statusCode: 403,
+      statusMessage: "Not allowed to authorize this client.",
+    });
+
+  if (!client.peer)
+    throw createError({
+      statusCode: 500,
+      statusMessage: "No client listening for authorization.",
+    });
+
+  const token = await clientHandler.generateAuthToken(clientId);
+
+  await clientHandler.sendAuthToken(clientId, token);
+
+  return;
+});