사소한 리팩토링

test/unit/crypto.test.ts

@@ -0,0 +1,45 @@
+import { describe, expect, it } from "vitest";
+import {
+  decodeFromBase64,
+  decryptChunk,
+  decryptString,
+  encodeToBase64,
+  encryptChunk,
+  encryptString,
+  generateDataKey,
+} from "#lib/shared/crypto/index.ts";
+
+describe("base64", () => {
+  it("round-trips large buffers", () => {
+    const data = Uint8Array.from({ length: 1024 * 1024 }, (_, i) => (i * 31) % 256);
+    const encoded = encodeToBase64(data);
+    expect(new Uint8Array(decodeFromBase64(encoded))).toEqual(data);
+    expect(encodeToBase64(data.buffer)).toBe(encoded);
+  });
+});
+
+describe("AES-GCM", () => {
+  it("round-trips strings", async () => {
+    const { dataKey } = await generateDataKey();
+    const { ciphertext, iv } = await encryptString("안녕하세요.jpg", dataKey);
+    expect(await decryptString(ciphertext, iv, dataKey)).toBe("안녕하세요.jpg");
+  });
+
+  it("round-trips chunks", async () => {
+    const { dataKey } = await generateDataKey();
+    const chunk = crypto.getRandomValues(new Uint8Array(4096));
+
+    const encrypted = await encryptChunk(chunk.buffer, dataKey);
+
+    expect(encrypted.byteLength).toBe(4096 + 12 + 16);
+    expect(new Uint8Array(await decryptChunk(encrypted, dataKey))).toEqual(chunk);
+  });
+
+  it("rejects tampered chunks", async () => {
+    const { dataKey } = await generateDataKey();
+    const encrypted = new Uint8Array(await encryptChunk(new Uint8Array(32).buffer, dataKey));
+    encrypted[20]! ^= 1;
+
+    await expect(decryptChunk(encrypted.buffer, dataKey)).rejects.toThrow();
+  });
+});