fix: validate attendance checkin payload

internal/httpapi/api.go

@@ -248,31 +248,65 @@ func (a *API) attendanceCheckins(w http.ResponseWriter, r *http.Request, p *auth
 		return
 	}
 	var body struct {
-		Date       string `json:"date"`
+		Date       string          `json:"date"`
-		Action     string `json:"action"`
+		Action     string          `json:"action"`
-		RuleID     string `json:"rule_id"`
+		RuleID     string          `json:"rule_id"`
-		ShiftID    string `json:"shift_id"`
+		ShiftID    string          `json:"shift_id"`
-		ClientTime string `json:"client_time"`
+		ClientTime string          `json:"client_time"`
-		Location   string `json:"location"`
+		Location   json.RawMessage `json:"location"`
-		Wifi       string `json:"wifi"`
+		Wifi       json.RawMessage `json:"wifi"`
-		Device     string `json:"device"`
+		Device     json.RawMessage `json:"device"`
 	}
 	if !decodeBody(w, r, &body) {
 		return
 	}
+	action := strings.TrimSpace(body.Action)
+	if action == "" || len(action) > 32 {
+		writeError(w, r, http.StatusBadRequest, 30000, reasonMalformedRequest, "malformed request", map[string]any{"field": "action"})
+		return
+	}
+	ruleID := strings.TrimSpace(body.RuleID)
+	if len(ruleID) > 64 {
+		writeError(w, r, http.StatusBadRequest, 30000, reasonMalformedRequest, "malformed request", map[string]any{"field": "rule_id"})
+		return
+	}
+	shiftID := strings.TrimSpace(body.ShiftID)
+	if shiftID == "" {
+		writeError(w, r, http.StatusBadRequest, 30000, reasonMalformedRequest, "malformed request", map[string]any{"field": "shift_id"})
+		return
+	}
 	date, err := parseDate(body.Date)
 	if err != nil {
 		writeError(w, r, http.StatusBadRequest, 30000, reasonMalformedRequest, "malformed request", map[string]any{"field": "date"})
 		return
 	}
+	if maxShiftIDLength := maxAttendanceShiftIDLength(p.UserID, date); len(shiftID) > maxShiftIDLength {
+		writeError(w, r, http.StatusBadRequest, 30000, reasonMalformedRequest, "malformed request", map[string]any{"field": "shift_id", "max_length": maxShiftIDLength})
+		return
+	}
 	clientTime, err := parseTime(body.ClientTime)
 	if err != nil {
 		writeError(w, r, http.StatusBadRequest, 30000, reasonMalformedRequest, "malformed request", map[string]any{"field": "client_time"})
 		return
 	}
+	location, err := normalizeJSONObject(body.Location)
+	if err != nil {
+		writeError(w, r, http.StatusBadRequest, 30000, reasonMalformedRequest, "malformed request", map[string]any{"field": "location"})
+		return
+	}
+	wifi, err := normalizeJSONObject(body.Wifi)
+	if err != nil {
+		writeError(w, r, http.StatusBadRequest, 30000, reasonMalformedRequest, "malformed request", map[string]any{"field": "wifi"})
+		return
+	}
+	device, err := normalizeJSONObject(body.Device)
+	if err != nil {
+		writeError(w, r, http.StatusBadRequest, 30000, reasonMalformedRequest, "malformed request", map[string]any{"field": "device"})
+		return
+	}
 	record, checkin, err := a.store.CreateAttendanceCheckin(r.Context(), p.UserID, "attc_"+randomToken(12), store.AttendanceCheckinRequest{
-		Date: date, Action: strings.TrimSpace(body.Action), RuleID: strings.TrimSpace(body.RuleID), ShiftID: strings.TrimSpace(body.ShiftID),
+		Date: date, Action: action, RuleID: ruleID, ShiftID: shiftID,
-		ClientTime: clientTime, Location: strings.TrimSpace(body.Location), Wifi: strings.TrimSpace(body.Wifi), Device: strings.TrimSpace(body.Device), IdempotencyKey: idempotencyKey,
+		ClientTime: clientTime, Location: location, Wifi: wifi, Device: device, IdempotencyKey: idempotencyKey,
 	})
 	if err != nil {
 		writeStoreError(w, r, err)
@@ -957,6 +991,34 @@ func parseTime(value string) (time.Time, error) {
 	return time.ParseInLocation("2006-01-02 15:04:05", value, time.Local)
 }
 
+func maxAttendanceShiftIDLength(userID int64, date time.Time) int {
+	prefix := fmt.Sprintf("att_%d_%s_", userID, date.Format("20060102"))
+	return 64 - len(prefix)
+}
+
+func normalizeJSONObject(raw json.RawMessage) (string, error) {
+	if len(raw) == 0 || strings.TrimSpace(string(raw)) == "" || string(raw) == "null" {
+		return "{}", nil
+	}
+	var text string
+	if err := json.Unmarshal(raw, &text); err == nil {
+		text = strings.TrimSpace(text)
+		if text == "" || text == "null" {
+			return "{}", nil
+		}
+		raw = json.RawMessage(text)
+	}
+	var value map[string]any
+	if err := json.Unmarshal(raw, &value); err != nil {
+		return "", err
+	}
+	normalized, err := json.Marshal(value)
+	if err != nil {
+		return "", err
+	}
+	return string(normalized), nil
+}
+
 func randomToken(size int) string {
 	buf := make([]byte, size)
 	if _, err := rand.Read(buf); err != nil {