하나의 공개 키로 여러 계정에 로그인할 수 있도록 구현

src/routes/(fullscreen)/auth/login/+page.svelte

@@ -14,7 +14,7 @@
   const login = async () => {
     // TODO: Validation
 
-    if (await requestLogin(email, password)) {
+    if (await requestLogin(email, password, $keyPairStore)) {
       await goto(
         $keyPairStore
           ? data.redirectPath

src/routes/(fullscreen)/auth/login/service.ts

@@ -1,10 +1,49 @@
-export const requestLogin = async (email: string, password: string) => {
-  const res = await fetch("/api/auth/login", {
+import { exportRSAKeyToBase64 } from "$lib/modules/crypto";
+import { requestPubKeyRegistration } from "../../key/export/service";
+
+const callLoginAPI = async (email: string, password: string, pubKeyBase64?: string) => {
+  return await fetch("/api/auth/login", {
     method: "POST",
     headers: {
       "Content-Type": "application/json",
     },
-    body: JSON.stringify({ email, password }),
+    body: JSON.stringify({
+      email,
+      password,
+      pubKey: pubKeyBase64,
+    }),
   });
-  return res.ok;
+};
+
+export const requestLogin = async (
+  email: string,
+  password: string,
+  keyPair: CryptoKeyPair | null,
+  registerPubKey = true,
+): Promise<boolean> => {
+  const pubKeyBase64 = keyPair
+    ? await exportRSAKeyToBase64(keyPair.publicKey, "public")
+    : undefined;
+  let loginRes = await callLoginAPI(email, password, pubKeyBase64);
+  if (loginRes.ok) {
+    return true;
+  } else if (loginRes.status !== 401 || !keyPair || !registerPubKey) {
+    return false;
+  }
+
+  const { message } = await loginRes.json();
+  if (message !== "Unregistered public key") {
+    return false;
+  }
+
+  loginRes = await callLoginAPI(email, password);
+  if (!loginRes.ok) {
+    return false;
+  }
+
+  if (await requestPubKeyRegistration(pubKeyBase64!, keyPair.privateKey)) {
+    return requestLogin(email, password, keyPair, false);
+  } else {
+    return false;
+  }
 };