Add a passphrase-locked vault

A second notebook whose pages are encrypted with a key made from a passphrase plus the server key. It is unlocked into memory only (15 minutes idle, Lock, or sign-out), is not in search, lists or downloads of the ordinary notebook, and limits wrong guesses.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/web/web_test.go

@@ -677,3 +677,160 @@ func TestKeyIsMadeOnceAndKept(t *testing.T) {
 		t.Fatalf("a short key was accepted: %v", err)
 	}
 }
+
+// ---- the vault ----
+
+func withVault(t *testing.T) *env {
+	t.Helper()
+	old := vaultIterations
+	vaultIterations = 1000
+	t.Cleanup(func() { vaultIterations = old })
+	return setup(t, nil)
+}
+
+// vaultCookies returns the sign-in cookies plus the vault token from a response.
+func vaultCookies(ses []*http.Cookie, w *httptest.ResponseRecorder) []*http.Cookie {
+	if v := cookieNamed(w, vaultCookie); v != nil && v.Value != "" {
+		return append(append([]*http.Cookie{}, ses...), v)
+	}
+	return ses
+}
+
+func TestVaultLifecycle(t *testing.T) {
+	e := withVault(t)
+	a := e.signIn(alice)
+
+	var info struct{ Exists, Unlocked bool }
+	jsonOf(t, e.do("GET", "/api/vault", nil, a), &info)
+	if info.Exists || info.Unlocked {
+		t.Fatalf("a new person already has a vault: %+v", info)
+	}
+	if w := e.do("GET", "/api/vault/notes", nil, a); w.Code != http.StatusLocked {
+		t.Fatalf("a vault that does not exist is not locked: %d", w.Code)
+	}
+	if w := e.do("POST", "/api/vault", map[string]string{"passphrase": "short"}, a); w.Code != http.StatusBadRequest {
+		t.Fatalf("a short passphrase: %d", w.Code)
+	}
+	w := e.do("POST", "/api/vault", map[string]string{"passphrase": "correct horse battery"}, a)
+	if w.Code != http.StatusOK {
+		t.Fatalf("create: %d %s", w.Code, w.Body)
+	}
+	tok := cookieNamed(w, vaultCookie)
+	if tok == nil || !tok.HttpOnly || tok.Value == "" {
+		t.Fatalf("vault cookie: %+v", tok)
+	}
+	open := vaultCookies(a, w)
+
+	// a page in the vault
+	var n struct{ ID string }
+	if w := e.do("POST", "/api/vault/notes", map[string]string{"title": "Bank codes", "body": "hunter2 and the safe number"}, open); w.Code != http.StatusOK && w.Code != http.StatusCreated {
+		t.Fatalf("create page: %d %s", w.Code, w.Body)
+	} else {
+		jsonOf(t, w, &n)
+	}
+	if w := e.do("GET", "/api/vault/notes/"+n.ID, nil, open); w.Code != http.StatusOK || !strings.Contains(w.Body.String(), "hunter2") {
+		t.Fatalf("read page: %d %s", w.Code, w.Body)
+	}
+
+	// it is nowhere in the ordinary notebook
+	for _, path := range []string{"/api/notes", "/api/pages", "/api/find?q=hunter2", "/api/find?q=Bank"} {
+		if w := e.do("GET", path, nil, open); strings.Contains(w.Body.String(), "hunter2") || strings.Contains(w.Body.String(), "Bank codes") {
+			t.Fatalf("%s shows the vault: %s", path, w.Body)
+		}
+	}
+	if w := e.do("GET", "/api/notes/"+n.ID, nil, open); w.Code != http.StatusNotFound {
+		t.Fatalf("a vault page opens as an ordinary one: %d", w.Code)
+	}
+	if w := e.do("GET", "/api/export", nil, open); bytes.Contains(w.Body.Bytes(), []byte("hunter2")) {
+		t.Fatal("the vault is in the download")
+	}
+	var found struct{ Hits []struct{ ID string } }
+	jsonOf(t, e.do("GET", "/api/vault/find?q=safe", nil, open), &found)
+	if len(found.Hits) != 1 {
+		t.Fatalf("vault search: %+v", found)
+	}
+
+	// locking, and the old cookie no longer opens anything
+	if w := e.do("POST", "/api/vault/lock", nil, open); w.Code != http.StatusOK {
+		t.Fatalf("lock: %d", w.Code)
+	}
+	if w := e.do("GET", "/api/vault/notes/"+n.ID, nil, open); w.Code != http.StatusLocked {
+		t.Fatalf("the vault opened after locking: %d", w.Code)
+	}
+
+	// the wrong passphrase, then the right one
+	if w := e.do("POST", "/api/vault/unlock", map[string]string{"passphrase": "wrong horse battery"}, a); w.Code != http.StatusForbidden {
+		t.Fatalf("wrong passphrase: %d", w.Code)
+	}
+	w = e.do("POST", "/api/vault/unlock", map[string]string{"passphrase": "correct horse battery"}, a)
+	if w.Code != http.StatusOK {
+		t.Fatalf("unlock: %d %s", w.Code, w.Body)
+	}
+	if w := e.do("GET", "/api/vault/notes/"+n.ID, nil, vaultCookies(a, w)); w.Code != http.StatusOK || !strings.Contains(w.Body.String(), "hunter2") {
+		t.Fatalf("read after unlock: %d", w.Code)
+	}
+	if w := e.do("POST", "/api/vault", map[string]string{"passphrase": "another passphrase"}, a); w.Code != http.StatusConflict {
+		t.Fatalf("a second vault: %d", w.Code)
+	}
+}
+
+func TestVaultIsEncryptedOnDiskAndPrivate(t *testing.T) {
+	e := withVault(t)
+	a, b := e.signIn(alice), e.signIn(bob)
+	w := e.do("POST", "/api/vault", map[string]string{"passphrase": "correct horse battery"}, a)
+	open := vaultCookies(a, w)
+	e.do("POST", "/api/vault/notes", map[string]string{"title": "Moonlight plan", "body": "tell nobody"}, open)
+
+	filepath.WalkDir(filepath.Join(e.dir, "data"), func(p string, d os.DirEntry, err error) error {
+		if err != nil || d.IsDir() {
+			return nil
+		}
+		raw, _ := os.ReadFile(p)
+		for _, s := range []string{"Moonlight", "tell nobody", "correct horse"} {
+			if bytes.Contains(raw, []byte(s)) {
+				t.Errorf("%s holds %q in the clear", p, s)
+			}
+		}
+		return nil
+	})
+
+	// Bob cannot use Alice's vault cookie, and has no vault of his own
+	stolen := append(append([]*http.Cookie{}, b...), cookieNamed(w, vaultCookie))
+	if w := e.do("GET", "/api/vault/notes", nil, stolen); w.Code != http.StatusLocked {
+		t.Fatalf("Bob opened Alice's vault with her cookie: %d", w.Code)
+	}
+	if w := e.do("POST", "/api/vault/unlock", map[string]string{"passphrase": "correct horse battery"}, b); w.Code != http.StatusNotFound {
+		t.Fatalf("Bob unlocking a vault he does not have: %d", w.Code)
+	}
+	// signing out locks it
+	e.do("POST", "/api/logout", nil, open)
+	if w := e.do("GET", "/api/vault/notes", nil, open); w.Code == http.StatusOK {
+		t.Fatal("the vault stayed open after signing out")
+	}
+}
+
+func TestVaultGuessingIsLimited(t *testing.T) {
+	e := withVault(t)
+	a := e.signIn(alice)
+	e.do("POST", "/api/vault", map[string]string{"passphrase": "correct horse battery"}, a)
+	e.do("POST", "/api/vault/lock", nil, a)
+	for i := 0; i < vaultTries; i++ {
+		if w := e.do("POST", "/api/vault/unlock", map[string]string{"passphrase": fmt.Sprintf("guess number %d", i)}, a); w.Code != http.StatusForbidden {
+			t.Fatalf("guess %d: %d", i, w.Code)
+		}
+	}
+	if w := e.do("POST", "/api/vault/unlock", map[string]string{"passphrase": "correct horse battery"}, a); w.Code != http.StatusTooManyRequests {
+		t.Fatalf("even the right passphrase is held back after too many guesses: %d", w.Code)
+	}
+}
+
+func TestVaultNeedsSignInAndHeader(t *testing.T) {
+	e := withVault(t)
+	if w := e.do("GET", "/api/vault", nil, nil); w.Code != http.StatusUnauthorized {
+		t.Fatalf("no sign-in: %d", w.Code)
+	}
+	a := e.signIn(alice)
+	if w := e.do("POST", "/api/vault", map[string]string{"passphrase": "correct horse battery"}, a, "X-Mako", ""); w.Code != http.StatusForbidden {
+		t.Fatalf("no header: %d", w.Code)
+	}
+}