App 2.12.0, server 2.5.0: enter settings on the phone

The ABRP credentials are long to type on the car. "Enter on phone"
(Live data tab, and Settings next to the charging price) shows a QR
code; it opens a form on the server where the phone sends the ABRP API
key and user token, charging price and usable capacity, confirmed with
the approval password. The car polls with its own token and collects
the values once, then saves them through the same checks as the fields
on screen.

Same device-flow shape as pairing. The server keeps the values in memory
only, at most ten minutes, hands them out once with no-store, and never
logs them or puts them back into the page; a paired token only reaches
its own installation's request. Pairing's QR dialog is now shared
(PhoneQrDialog), and the phone pages share one stylesheet.

The config file also takes charging_price and usable_kwh.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QLJfZQZeAKAwSqViTmLzki

server/handoff_test.go

@@ -0,0 +1,143 @@
+package main
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+	"testing"
+	"time"
+)
+
+func startHandoff(t *testing.T, h http.Handler, token string) (deviceCode, userCode string) {
+	t.Helper()
+	rec := do(t, h, "POST", "/v1/settings/start", token, `{"installationId":"`+testInstallation+`"}`)
+	if rec.Code != 201 {
+		t.Fatalf("start: %d %s", rec.Code, rec.Body)
+	}
+	var got map[string]any
+	if err := json.Unmarshal(rec.Body.Bytes(), &got); err != nil {
+		t.Fatal(err)
+	}
+	if got["verificationUriComplete"] != "https://car.example.com/settings?code="+got["userCode"].(string) {
+		t.Fatalf("uri %v", got["verificationUriComplete"])
+	}
+	return got["deviceCode"].(string), got["userCode"].(string)
+}
+
+func sendSettings(t *testing.T, h http.Handler, form url.Values) *httptest.ResponseRecorder {
+	t.Helper()
+	req := httptest.NewRequest("POST", "/settings", strings.NewReader(form.Encode()))
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	rec := httptest.NewRecorder()
+	h.ServeHTTP(rec, req)
+	return rec
+}
+
+func TestSettingsTravelFromThePhoneToTheCarOnce(t *testing.T) {
+	api, _ := newTestAPI()
+	h := api.Routes()
+	if rec := do(t, h, "POST", "/v1/settings/start", "", `{"installationId":"`+testInstallation+`"}`); rec.Code != 401 {
+		t.Fatalf("start without a token: %d", rec.Code)
+	}
+	deviceCode, userCode := startHandoff(t, h, testToken)
+	poll := func() *httptest.ResponseRecorder {
+		return do(t, h, "POST", "/v1/settings/poll", testToken, `{"deviceCode":"`+deviceCode+`"}`)
+	}
+	if rec := poll(); rec.Code != 202 {
+		t.Fatalf("before the phone: %d", rec.Code)
+	}
+	page := do(t, h, "GET", "/settings?code="+userCode, "", "")
+	if page.Code != 200 || !strings.Contains(page.Body.String(), userCode) {
+		t.Fatalf("page %d", page.Code)
+	}
+
+	form := url.Values{"code": {userCode}, "abrpApiKey": {"api-key-1234"}, "abrpToken": {"user-token-5678"},
+		"price": {"0,39"}, "password": {"wrong"}}
+	if rec := sendSettings(t, h, form); rec.Code != 401 || strings.Contains(rec.Body.String(), "user-token-5678") {
+		t.Fatalf("wrong password: %d (credentials must not be echoed)", rec.Code)
+	}
+	form.Set("password", testApprovalPassword)
+	if rec := sendSettings(t, h, form); rec.Code != 200 {
+		t.Fatalf("send: %d %s", rec.Code, rec.Body)
+	}
+	if rec := sendSettings(t, h, form); rec.Code != 409 {
+		t.Fatalf("sent twice: %d", rec.Code)
+	}
+
+	rec := poll()
+	var got PhoneSettings
+	if rec.Code != 200 || json.Unmarshal(rec.Body.Bytes(), &got) != nil {
+		t.Fatalf("collect: %d %s", rec.Code, rec.Body)
+	}
+	if got.AbrpAPIKey != "api-key-1234" || got.AbrpToken != "user-token-5678" || got.PricePerKwh == nil ||
+		*got.PricePerKwh != 0.39 || got.UsableKwh != nil {
+		t.Fatalf("settings %+v", got)
+	}
+	if rec.Header().Get("Cache-Control") != "no-store" {
+		t.Fatal("credentials cacheable")
+	}
+	if rec := poll(); rec.Code != 410 {
+		t.Fatalf("collected twice: %d", rec.Code)
+	}
+}
+
+func TestSettingsAreOnlyForTheCarThatAsked(t *testing.T) {
+	api, _ := newTestAPI()
+	h := api.Routes()
+	deviceCode, userCode := startHandoff(t, h, testToken)
+	_ = api.Handoff.Fill(userCode, PhoneSettings{AbrpToken: "user-token-5678"})
+	// A car paired as another installation cannot open a request for this one, nor collect it.
+	other := caller{installationID: "7e2b3c4d-5e6f-4a70-9b8c-1d2e3f4a5b6c"}
+	if s, err := api.Handoff.Poll(deviceCode, other.mayUse); s != nil || err == nil {
+		t.Fatal("another car collected the settings")
+	}
+	if s, err := api.Handoff.Poll(deviceCode, caller{}.mayUse); s == nil || err != nil {
+		t.Fatalf("the car itself could not collect: %v", err)
+	}
+}
+
+func TestPhoneSettingsAreChecked(t *testing.T) {
+	for name, form := range map[string]url.Values{
+		"nothing":        {},
+		"short token":    {"abrpToken": {"abc"}},
+		"spaced key":     {"abrpApiKey": {"has a space here"}},
+		"price absurd":   {"price": {"250"}},
+		"usable too low": {"usable": {"3"}},
+		"not a number":   {"price": {"cheap"}},
+	} {
+		if _, err := phoneSettingsFromForm(form); err == nil {
+			t.Errorf("%s accepted", name)
+		}
+	}
+	s, err := phoneSettingsFromForm(url.Values{"usable": {" 50,8 "}})
+	if err != nil || s.UsableKwh == nil || *s.UsableKwh != 50.8 || s.AbrpToken != "" {
+		t.Fatalf("%+v %v", s, err)
+	}
+}
+
+func TestHandoffRequestsExpireAndAreReplaced(t *testing.T) {
+	h := NewHandoff()
+	first, _ := h.Start(testInstallation)
+	second, _ := h.Start(testInstallation)
+	if _, err := h.Poll(first.deviceCode, caller{}.mayUse); err == nil {
+		t.Fatal("the replaced request is still open")
+	}
+	h.Now = func() time.Time { return time.Now().Add(pairingTTL + time.Second) }
+	if err := h.Fill(second.userCode, PhoneSettings{AbrpToken: "user-token-5678"}); err == nil {
+		t.Fatal("an expired request took settings")
+	}
+}
+
+func TestPhoneSettingsNeedPairingSwitchedOn(t *testing.T) {
+	api, _ := newTestAPI()
+	api.Pairing = NewPairing("", nil)
+	h := api.Routes()
+	if rec := do(t, h, "POST", "/v1/settings/start", testToken, `{"installationId":"`+testInstallation+`"}`); rec.Code != 404 {
+		t.Fatalf("start: %d", rec.Code)
+	}
+	if rec := do(t, h, "GET", "/settings", "", ""); rec.Code != 404 {
+		t.Fatalf("page: %d", rec.Code)
+	}
+}