M12/SEC-003: encrypt sync identity private key under derived vault key

@@ -0,0 +1,111 @@1+/**2+ * sync-identity-encryption.test.ts — M12/SEC-0033+ *4+ * getSyncIdentity must encrypt the X25519 private key under the vault's5+ * derived key before persisting, must require unlock to read, and must6+ * migrate v0 (unencrypted) records to v1 (encrypted) on first read.7+ */8+9+import { beforeEach, describe, expect, it, vi } from "vitest";10+11+describe("sync identity encryption (M12/SEC-003)", () => {12+  let storage: Record<string, unknown>;13+14+  beforeEach(() => {15+    vi.resetModules();16+    vi.useRealTimers();17+    storage = {};18+19+    const chromeMock = {20+      runtime: { id: "peach-extension", sendMessage: vi.fn() },21+      storage: {22+        local: {23+          get: vi.fn(async (key?: string | string[]) => {24+            if (!key) return storage;25+            if (typeof key === "string") return { [key]: storage[key] };26+            return key.reduce<Record<string, unknown>>((acc, k) => {27+              acc[k] = storage[k];28+              return acc;29+            }, {});30+          }),31+          set: vi.fn(async (next: Record<string, unknown>) => {32+            Object.assign(storage, next);33+          }),34+          remove: vi.fn(async (keys: string | string[]) => {35+            const list = Array.isArray(keys) ? keys : [keys];36+            for (const k of list) delete storage[k];37+          }),38+        },39+        session: {40+          get: vi.fn(async () => ({})),41+          set: vi.fn(async () => {}),42+          remove: vi.fn(async () => {}),43+        },44+      },45+      alarms: {46+        clear: vi.fn(),47+        create: vi.fn(),48+        onAlarm: { addListener: vi.fn() },49+      },50+      idle: {51+        setDetectionInterval: vi.fn(),52+        onStateChanged: { addListener: vi.fn() },53+      },54+    } as unknown as typeof chrome;55+    (globalThis as { chrome?: typeof chrome }).chrome = chromeMock;56+  });57+58+  it("throws vault_locked when called before unlock", async () => {59+    const vault = await import("./vault");60+    await expect(vault.getSyncIdentity()).rejects.toThrow(/vault_locked/);61+  });62+63+  it("persisted record contains no plaintext private key field after generation", async () => {64+    const vault = await import("./vault");65+    await vault.createVault("test-pass-12345");66+    const { privateKeyBytes } = await vault.getSyncIdentity();67+68+    const stored = JSON.parse(storage.peach_sync_identity as string) as Record<string, unknown>;69+    expect(stored.priv).toBeUndefined();70+    expect(typeof stored.enc_priv).toBe("string");71+    expect(typeof stored.enc_nonce).toBe("string");72+    expect(typeof stored.enc_tag).toBe("string");73+    expect(typeof stored.pub).toBe("string");74+    expect(privateKeyBytes.length).toBe(32);75+  });76+77+  it("subsequent reads return the same private key bytes", async () => {78+    const vault = await import("./vault");79+    await vault.createVault("test-pass-12345");80+    const first = await vault.getSyncIdentity();81+    const second = await vault.getSyncIdentity();82+    expect(Array.from(second.privateKeyBytes)).toEqual(Array.from(first.privateKeyBytes));83+    expect(second.publicKeyHex).toBe(first.publicKeyHex);84+  });85+86+  it("migrates v0 (unencrypted priv/pub) record to v1 encrypted form", async () => {87+    const vault = await import("./vault");88+    await vault.createVault("test-pass-12345");89+90+    // Overwrite with a v0-shaped record.91+    const fakePriv = new Uint8Array(32).fill(7);92+    const fakePub = new Uint8Array(32).fill(8);93+    const b64 = (b: Uint8Array) => {94+      let s = "";95+      for (const v of b) s += String.fromCharCode(v);96+      return btoa(s);97+    };98+    storage.peach_sync_identity = JSON.stringify({99+      priv: b64(fakePriv),100+      pub: b64(fakePub),101+    });102+103+    const result = await vault.getSyncIdentity();104+    expect(Array.from(result.privateKeyBytes)).toEqual(Array.from(fakePriv));105+106+    // Storage was upgraded.107+    const stored = JSON.parse(storage.peach_sync_identity as string) as Record<string, unknown>;108+    expect(stored.priv).toBeUndefined();109+    expect(typeof stored.enc_priv).toBe("string");110+  });111+});