feat: Add Sliding expiration for user_sessions

The user_session is valid for 24 hours, but the session will be bumped if it has been over an hour since the last update. An hour was set as a deadline, so that we would not update the user_session rows too often.

README.md

@@ -15,7 +15,9 @@ A simple Go backend with authentication using native `net/http` and PostgreSQL.
 
 - Go 1.24+
 - PostgreSQL
-- [goose](https://github.com/pressly/goose) for migrations, [air](https://github.com/air-verse/air) for live reload (optional):
+- [goose](https://github.com/pressly/goose) for migrationns
+- [sqlc](https://github.com/sqlc-dev/sqlc) for generating typed SQL queries
+- [air](https://github.com/air-verse/air) for live reload (optional)
   ```bash
   go install github.com/pressly/goose/v3/cmd/goose@latest
   go install github.com/air-verse/air@latest
@@ -24,6 +26,7 @@ A simple Go backend with authentication using native `net/http` and PostgreSQL.
 ## Setup
 
 1. Copy environment variables:
+
    ```bash
    cp .env.example .env
    ```
@@ -31,11 +34,13 @@ A simple Go backend with authentication using native `net/http` and PostgreSQL.
 2. Update `.env` with your database credentials (both the `DB_*` and `GOOSE_*` values).
 
 3. Install dependencies:
+
    ```bash
    go mod tidy
    ```
 
 4. Run database migrations:
+
    ```bash
    ./scripts/goose.sh up
    ```

cmd/main.go

@@ -14,12 +14,10 @@ import (
 )
 
 func main() {
-	// Load .env file
 	if err := godotenv.Load(); err != nil {
 		log.Println("No .env file found")
 	}
 
-	// Connect to database
 	db, err := database.Connect()
 	if err != nil {
 		log.Fatal("Failed to connect to database:", err)
@@ -33,10 +31,8 @@ func main() {
 
 	handler := handlers.NewHandler(userService, authService)
 
-	// Create router
 	mux := http.NewServeMux()
 
-	// Routes
 	mux.Handle("GET /static/", http.StripPrefix("/static/", http.FileServer(http.Dir("./ui/static"))))
 
 	mux.HandleFunc("GET /{$}", handler.HomeHandler)
@@ -48,10 +44,8 @@ func main() {
 	mux.HandleFunc("POST /api/logout", handler.LogoutHandler)
 	mux.HandleFunc("POST /api/signup", handler.SignUpHandler)
 
-	// Apply middleware (CORS first, then logging)
 	muxMiddleware := handlers.LoggingMiddleware(handlers.CORSMiddleware(mux))
 
-	// Start server
 	port := getEnv("PORT", "8080")
 	log.Printf("Server starting on port %s", port)
 

internal/auth/session.go

@@ -3,11 +3,13 @@ package auth
 import (
 	"crypto/rand"
 	"crypto/sha256"
+	"net/http"
 	"strings"
 	"time"
 )
 
 const sessionExpiresInSeconds = 60 * 60 * 24 // 1 day
+const activityCheckInterval = 60 * 60        // 1 hour
 
 func GenerateSecureRandomString() (string, error) {
 	// Human readable alphabet (a-z, 0-9 without l, o, 0, 1 to avoid confusion)
@@ -34,6 +36,35 @@ func HashSecret(secret string) []byte {
 	return hash[:]
 }
 
+func CheckNeedForBump(lastVerified time.Time) bool {
+	return time.Since(lastVerified).Seconds() >= activityCheckInterval
+}
+
 func CheckExpiration(expirarion time.Time) bool {
 	return time.Since(expirarion).Seconds() >= sessionExpiresInSeconds
 }
+
+func NewSessionCookie(token string, deleted bool) *http.Cookie {
+	cookie := &http.Cookie{
+		Name:     "session",
+		Value:    token,
+		HttpOnly: true,
+		SameSite: http.SameSiteLaxMode,
+		MaxAge:   sessionExpiresInSeconds,
+		Path:     "/",
+	}
+
+	if deleted {
+		cookie = &http.Cookie{
+			Name:     "session",
+			Value:    "",
+			HttpOnly: true,
+			SameSite: http.SameSiteLaxMode,
+			MaxAge:   -1,
+			Path:     "/",
+		}
+	}
+
+	return cookie
+
+}

internal/database/queries/sessions.sql

@@ -1,12 +1,17 @@
 -- name: SelectSessionById :one
-SELECT id, secret_hash, user_id, created_at
+SELECT id, secret_hash, user_id, last_verified_at, created_at, updated_at
 FROM user_session
 WHERE id = $1;
 
 -- name: InsertSession :one
 INSERT INTO user_session (id, secret_hash, user_id)
 VALUES ($1, $2, $3)
-RETURNING id, secret_hash, user_id, created_at;
+RETURNING id, secret_hash, user_id, last_verified_at, created_at, updated_at;
+
+-- name: UpdateSessionVerifiedAt :one
+UPDATE user_session SET last_verified_at = NOW()
+WHERE id = $1
+RETURNING id, secret_hash, user_id, last_verified_at, created_at, updated_at;
 
 -- name: DeleteSessionById :exec
 DELETE FROM user_session WHERE id = $1;

internal/database/sqlc/models.go

@@ -21,5 +21,7 @@ type UserSession struct {
 	ID             string
 	SecretHash     []byte
 	UserID         string
+	LastVerifiedAt time.Time
 	CreatedAt      time.Time
+	UpdatedAt      time.Time
 }

internal/database/sqlc/sessions.sql.go

@@ -21,7 +21,7 @@ func (q *Queries) DeleteSessionById(ctx context.Context, id string) error {
 const insertSession = `-- name: InsertSession :one
 INSERT INTO user_session (id, secret_hash, user_id)
 VALUES ($1, $2, $3)
-RETURNING id, secret_hash, user_id, created_at
+RETURNING id, secret_hash, user_id, last_verified_at, created_at, updated_at
 `
 
 type InsertSessionParams struct {
@@ -37,13 +37,15 @@ func (q *Queries) InsertSession(ctx context.Context, arg InsertSessionParams) (U
 		&i.ID,
 		&i.SecretHash,
 		&i.UserID,
+		&i.LastVerifiedAt,
 		&i.CreatedAt,
+		&i.UpdatedAt,
 	)
 	return i, err
 }
 
 const selectSessionById = `-- name: SelectSessionById :one
-SELECT id, secret_hash, user_id, created_at
+SELECT id, secret_hash, user_id, last_verified_at, created_at, updated_at
 FROM user_session
 WHERE id = $1
 `
@@ -55,7 +57,29 @@ func (q *Queries) SelectSessionById(ctx context.Context, id string) (UserSession
 		&i.ID,
 		&i.SecretHash,
 		&i.UserID,
+		&i.LastVerifiedAt,
 		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}
+
+const updateSessionVerifiedAt = `-- name: UpdateSessionVerifiedAt :one
+UPDATE user_session SET last_verified_at = NOW()
+WHERE id = $1
+RETURNING id, secret_hash, user_id, last_verified_at, created_at, updated_at
+`
+
+func (q *Queries) UpdateSessionVerifiedAt(ctx context.Context, id string) (UserSession, error) {
+	row := q.db.QueryRowContext(ctx, updateSessionVerifiedAt, id)
+	var i UserSession
+	err := row.Scan(
+		&i.ID,
+		&i.SecretHash,
+		&i.UserID,
+		&i.LastVerifiedAt,
+		&i.CreatedAt,
+		&i.UpdatedAt,
 	)
 	return i, err
 }

internal/handlers/handler.go

@@ -2,6 +2,7 @@ package handlers
 
 import (
 	"context"
+	"go-backend/internal/auth"
 	"go-backend/internal/database/sqlc"
 	"go-backend/internal/services"
 	"log"
@@ -21,7 +22,7 @@ type UserService interface {
 
 type AuthService interface {
 	CreateSession(ctx context.Context, userID string) (*services.SessionWithToken, error)
-	ValidateSessionToken(ctx context.Context, token string) (*sqlc.UserSession, error)
+	ValidateSessionToken(ctx context.Context, token string) (*sqlc.UserSession, bool, error)
 	DeleteSession(ctx context.Context, token string) error
 }
 
@@ -45,7 +46,7 @@ func (h *Handler) HomeHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	session, err := h.auth.ValidateSessionToken(r.Context(), cookie.Value)
+	session, bump, err := h.auth.ValidateSessionToken(r.Context(), cookie.Value)
 
 	if err != nil {
 		log.Print(err.Error())
@@ -58,6 +59,10 @@ func (h *Handler) HomeHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if bump {
+		http.SetCookie(w, auth.NewSessionCookie(cookie.Value, false))
+	}
+
 	files := []string{
 		"./ui/html/base.tmpl",
 		"./ui/html/pages/index.tmpl",
@@ -81,7 +86,7 @@ func (h *Handler) LoginPageHandler(w http.ResponseWriter, r *http.Request) {
 	cookie, err := r.Cookie("session")
 
 	if cookie != nil {
-		session, err := h.auth.ValidateSessionToken(r.Context(), cookie.Value)
+		session, bump, err := h.auth.ValidateSessionToken(r.Context(), cookie.Value)
 
 		if err != nil {
 			log.Print(err.Error())
@@ -89,6 +94,10 @@ func (h *Handler) LoginPageHandler(w http.ResponseWriter, r *http.Request) {
 			return
 		}
 
+		if bump {
+			http.SetCookie(w, auth.NewSessionCookie(cookie.Value, false))
+		}
+
 		if session != nil {
 			http.Redirect(w, r, "/", http.StatusSeeOther)
 			return
@@ -118,7 +127,7 @@ func (h *Handler) SignUpPageHandler(w http.ResponseWriter, r *http.Request) {
 	cookie, err := r.Cookie("session")
 
 	if cookie != nil {
-		session, err := h.auth.ValidateSessionToken(r.Context(), cookie.Value)
+		session, bump, err := h.auth.ValidateSessionToken(r.Context(), cookie.Value)
 
 		if err != nil {
 			log.Print(err.Error())
@@ -126,6 +135,10 @@ func (h *Handler) SignUpPageHandler(w http.ResponseWriter, r *http.Request) {
 			return
 		}
 
+		if bump {
+			http.SetCookie(w, auth.NewSessionCookie(cookie.Value, false))
+		}
+
 		if session != nil {
 			http.Redirect(w, r, "/", http.StatusSeeOther)
 			return

internal/handlers/login.go

@@ -52,14 +52,7 @@ func (h *Handler) LoginHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	cookie := &http.Cookie{
-		Name:     "session",
-		Value:    session.Token,
-		HttpOnly: true,
-		SameSite: http.SameSiteLaxMode,
-		MaxAge:   86400, // 24 hours
-		Path:     "/",
-	}
+	cookie := auth.NewSessionCookie(session.Token, false)
 	http.SetCookie(w, cookie)
 
 	w.Header().Set("HX-Redirect", "/")
@@ -82,16 +75,7 @@ func (h *Handler) LogoutHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	cookie = &http.Cookie{
-		Name:     "session",
-		Value:    "",
-		HttpOnly: true,
-		SameSite: http.SameSiteLaxMode,
-		MaxAge:   -1,
-		Path:     "/",
-	}
-
-	http.SetCookie(w, cookie)
+	http.SetCookie(w, auth.NewSessionCookie("", true))
 
 	w.Header().Set("HX-Redirect", "/")
 	w.WriteHeader(http.StatusOK)

internal/handlers/signup.go

@@ -64,14 +64,7 @@ func (h *Handler) SignUpHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	cookie := &http.Cookie{
-		Name:     "session",
-		Value:    session.Token,
-		HttpOnly: true,
-		SameSite: http.SameSiteLaxMode,
-		MaxAge:   86400, // 24 hours
-		Path:     "/",
-	}
+	cookie := auth.NewSessionCookie(session.Token, false)
 	http.SetCookie(w, cookie)
 
 	w.Header().Set("HX-Redirect", "/")

internal/handlers/user.go

@@ -2,6 +2,7 @@ package handlers
 
 import (
 	"encoding/json"
+	"go-backend/internal/auth"
 	"net/http"
 )
 
@@ -25,16 +26,22 @@ func (h *Handler) UserHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// Validate session
-	session, err := h.auth.ValidateSessionToken(r.Context(), cookie.Value)
+	session, bump, err := h.auth.ValidateSessionToken(r.Context(), cookie.Value)
+
 	if err != nil {
 		http.Error(w, "Internal server error", http.StatusInternalServerError)
 		return
 	}
+
 	if session == nil {
 		http.Error(w, "Unauthorized", http.StatusUnauthorized)
 		return
 	}
 
+	if bump {
+		http.SetCookie(w, auth.NewSessionCookie(cookie.Value, false))
+	}
+
 	// Get user info
 	user, err := h.users.FindByID(r.Context(), session.UserID)
 	if err != nil {

internal/services/auth.go

@@ -58,10 +58,10 @@ func (s *AuthService) CreateSession(ctx context.Context, userID string) (*Sessio
 
 }
 
-func (s *AuthService) ValidateSessionToken(ctx context.Context, token string) (*sqlc.UserSession, error) {
+func (s *AuthService) ValidateSessionToken(ctx context.Context, token string) (*sqlc.UserSession, bool, error) {
 	tokenParts := strings.Split(token, ".")
 	if len(tokenParts) != 2 {
-		return nil, nil
+		return nil, false, nil
 	}
 
 	sessionID := tokenParts[0]
@@ -71,28 +71,38 @@ func (s *AuthService) ValidateSessionToken(ctx context.Context, token string) (*
 
 	if err != nil {
 		if errors.Is(err, sql.ErrNoRows) {
-			return nil, nil
+			return nil, false, nil
 		}
 
-		return nil, err
+		return nil, false, err
 	}
 
-	if auth.CheckExpiration(session.CreatedAt) {
+	if auth.CheckExpiration(session.LastVerifiedAt) {
 		err = s.queries.DeleteSessionById(ctx, sessionID)
 
 		if err != nil {
-			return nil, err
+			return nil, false, err
 		}
 
-		return nil, nil
+		return nil, false, nil
 	}
 
 	tokenSecretHash := auth.HashSecret(sessionSecret)
 	if subtle.ConstantTimeCompare(tokenSecretHash, session.SecretHash) != 1 {
-		return nil, nil
+		return nil, false, nil
 	}
 
-	return &session, nil
+	if auth.CheckNeedForBump(session.LastVerifiedAt) {
+		session, err = s.queries.UpdateSessionVerifiedAt(ctx, sessionID)
+
+		if err != nil {
+			return nil, false, err
+		}
+
+		return &session, true, nil
+	}
+
+	return &session, false, nil
 }
 
 func (s *AuthService) DeleteSession(ctx context.Context, token string) error {

migrations/00001_init.sql

@@ -15,7 +15,9 @@ CREATE TABLE IF NOT EXISTS user_session (
     id          TEXT PRIMARY KEY,
     secret_hash BYTEA NOT NULL,
     user_id     TEXT NOT NULL REFERENCES user_auth (id) ON DELETE CASCADE,
-    created_at  TIMESTAMPTZ NOT NULL DEFAULT now()
+    last_verified_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at  TIMESTAMPTZ NOT NULL DEFAULT now()
 );
 
 CREATE INDEX IF NOT EXISTS idx_user_session_user_id ON user_session (user_id);
@@ -34,6 +36,11 @@ CREATE TRIGGER user_auth_set_updated_at
     FOR EACH ROW
     EXECUTE FUNCTION set_updated_at();
 
+CREATE TRIGGER user_session_set_updated_at
+    BEFORE UPDATE ON user_session
+    FOR EACH ROW
+    EXECUTE FUNCTION set_updated_at();
+
 -- +goose Down
 
 DROP TRIGGER IF EXISTS user_auth_set_updated_at ON user_auth;

todo.txt

@@ -0,0 +1,7 @@
+[ ] Add secure TLS to cookies
+[ ] Add confirm email
+[ ] Add OTP (Scaleway?)
+[ ] Add OAuth (Google?)
+[ ] Add profile - patch user
+[ ] Add an admin role and admin panel
+[ ] Add forgotten pw flow