feat: auth handlers and session management

internal/server/auth.go

@@ -0,0 +1,94 @@
+package server
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"encoding/json"
+	"net/http"
+	"time"
+)
+
+type loginRequest struct {
+	Token string `json:"token"`
+}
+
+func (s *Server) handleLogin(w http.ResponseWriter, r *http.Request) {
+	ip := r.RemoteAddr
+
+	s.mu.Lock()
+	if lockTime, locked := s.loginLockout[ip]; locked && time.Now().Before(lockTime) {
+		s.mu.Unlock()
+		http.Error(w, "Too many attempts, locked for 60s", http.StatusForbidden)
+		return
+	}
+	s.mu.Unlock()
+
+	var req loginRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		http.Error(w, "Invalid JSON", http.StatusBadRequest)
+		return
+	}
+
+	if req.Token != s.accessToken {
+		s.mu.Lock()
+		s.loginAttempts[ip]++
+		if s.loginAttempts[ip] >= 5 {
+			s.loginLockout[ip] = time.Now().Add(60 * time.Second)
+			s.loginAttempts[ip] = 0
+		}
+		s.mu.Unlock()
+		http.Error(w, "Invalid token", http.StatusUnauthorized)
+		return
+	}
+
+	s.mu.Lock()
+	delete(s.loginAttempts, ip)
+	delete(s.loginLockout, ip)
+	s.mu.Unlock()
+
+	sessionID := generateSessionID()
+	s.mu.Lock()
+	s.sessions[sessionID] = time.Now().Unix()
+	s.mu.Unlock()
+
+	http.SetCookie(w, &http.Cookie{
+		Name:     "ydropbox_session",
+		Value:    sessionID,
+		Path:     "/",
+		HttpOnly: true,
+		SameSite: http.SameSiteLaxMode,
+		Secure:   true,
+		MaxAge:   7 * 24 * 60 * 60,
+	})
+
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(map[string]string{})
+}
+
+func (s *Server) handleLogout(w http.ResponseWriter, r *http.Request) {
+	cookie, err := r.Cookie("ydropbox_session")
+	if err != nil {
+		http.Error(w, "Not logged in", http.StatusUnauthorized)
+		return
+	}
+
+	s.mu.Lock()
+	delete(s.sessions, cookie.Value)
+	s.mu.Unlock()
+
+	http.SetCookie(w, &http.Cookie{
+		Name:   "ydropbox_session",
+		Value:  "",
+		Path:   "/",
+		MaxAge: -1,
+	})
+
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(map[string]string{})
+}
+
+func generateSessionID() string {
+	b := make([]byte, 32)
+	rand.Read(b)
+	return hex.EncodeToString(b)
+}