RSA 키 페어 생성 구현

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

@@ -0,0 +1,57 @@
+import { storeKeyPairIntoIndexedDB } from "$lib/indexedDB";
+
+type KeyType = "public" | "private";
+
+const generateRSAKeyPair = async () => {
+  const keyPair = await window.crypto.subtle.generateKey(
+    {
+      name: "RSA-OAEP",
+      modulusLength: 4096,
+      publicExponent: new Uint8Array([1, 0, 1]),
+      hash: "SHA-256",
+    } satisfies RsaHashedKeyGenParams,
+    true,
+    ["encrypt", "decrypt"],
+  );
+  return keyPair;
+};
+
+const exportKeyAsPem = async (key: CryptoKey, type: KeyType) => {
+  const exportedKey = await window.crypto.subtle.exportKey(
+    type === "public" ? "spki" : "pkcs8",
+    key,
+  );
+  const exportedKeyBase64 = btoa(String.fromCharCode(...new Uint8Array(exportedKey)))
+    .match(/.{1,64}/g)!
+    .join("\n");
+
+  const pemHeader = type === "public" ? "PUBLIC" : "PRIVATE";
+  const pem = `-----BEGIN ${pemHeader} KEY-----\n${exportedKeyBase64}\n-----END ${pemHeader} KEY-----\n`;
+  return pem;
+};
+
+const makeRSAKeyNonextractable = async (key: CryptoKey, type: KeyType) => {
+  const format = type === "public" ? "spki" : "pkcs8";
+  const keyUsage = type === "public" ? "encrypt" : "decrypt";
+  return await window.crypto.subtle.importKey(
+    format,
+    await window.crypto.subtle.exportKey(format, key),
+    {
+      name: "RSA-OAEP",
+      hash: "SHA-256",
+    } satisfies RsaHashedImportParams,
+    false,
+    [keyUsage],
+  );
+};
+
+export const generateKeyPair = async () => {
+  const keyPair = await generateRSAKeyPair();
+
+  const privKeySecure = await makeRSAKeyNonextractable(keyPair.privateKey, "private");
+  await storeKeyPairIntoIndexedDB(keyPair.publicKey, privKeySecure);
+
+  const pubKeyPem = await exportKeyAsPem(keyPair.publicKey, "public");
+  const privKeyPem = await exportKeyAsPem(keyPair.privateKey, "private");
+  return { pubKeyPem, privKeyPem };
+};