Feat: add models/cache/config

handlers/auth.go

@@ -0,0 +1,115 @@
+package handlers
+
+import (
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/json"
+	"golias/models"
+	"golias/utils"
+	"html/template"
+	"log/slog"
+	"net/http"
+	"strings"
+	"time"
+)
+
+func abortWithError(w http.ResponseWriter, msg string) {
+	tmpl := template.Must(template.ParseGlob("components/*.html"))
+	tmpl.ExecuteTemplate(w, "error", msg)
+}
+
+func HandleFrontLogin(w http.ResponseWriter, r *http.Request) {
+	r.ParseForm()
+	username := r.PostFormValue("username")
+	if username == "" {
+		msg := "username not provided"
+		slog.Error(msg)
+		abortWithError(w, msg)
+		return
+	}
+	// make sure username does not exists
+	cleanName := utils.RemoveSpacesFromStr(username)
+	// TODO: create user in db
+	// login user
+	cookie, err := makeCookie(cleanName, r.RemoteAddr)
+	if err != nil {
+		slog.Error("failed to login", "error", err)
+		abortWithError(w, err.Error())
+		return
+	}
+	http.SetCookie(w, cookie)
+	tmpl, err := template.ParseGlob("components/*.html")
+	if err != nil {
+		abortWithError(w, err.Error())
+		return
+	}
+	tmpl.ExecuteTemplate(w, "main", nil)
+}
+
+func makeCookie(username string, remote string) (*http.Cookie, error) {
+	// secret
+	// Create a new random session token
+	// sessionToken := xid.New().String()
+	sessionToken := "token"
+	expiresAt := time.Now().Add(time.Duration(cfg.SessionLifetime) * time.Second)
+	// Set the token in the session map, along with the session information
+	session := &models.Session{
+		Username: username,
+		Expiry:   expiresAt,
+	}
+	cookieName := "session_token"
+	// hmac to protect cookies
+	hm := hmac.New(sha256.New, []byte(cfg.CookieSecret))
+	hm.Write([]byte(cookieName))
+	hm.Write([]byte(sessionToken))
+	signature := hm.Sum(nil)
+	// b64 enc to avoid non-ascii
+	cookieValue := base64.URLEncoding.EncodeToString([]byte(
+		string(signature) + sessionToken))
+	cookie := &http.Cookie{
+		Name:     cookieName,
+		Value:    cookieValue,
+		Secure:   true,
+		HttpOnly: true,
+		SameSite: http.SameSiteNoneMode,
+		Domain:   cfg.ServerConfig.Host,
+	}
+	slog.Info("check remote addr for cookie set",
+		"remote", remote, "session", session)
+	if strings.Contains(remote, "192.168.0") {
+		// no idea what is going on
+		// cookie.Domain = "192.168.0.15"
+		cookie.Domain = "home.host"
+		slog.Info("changing cookie domain", "domain", cookie.Domain)
+	}
+	// set ctx?
+	// set user in session
+	if err := cacheSetSession(sessionToken, session); err != nil {
+		return nil, err
+	}
+	return cookie, nil
+}
+
+func cacheGetSession(key string) (*models.Session, error) {
+	userSessionB, err := memcache.Get(key)
+	if err != nil {
+		return nil, err
+	}
+	var us *models.Session
+	if err := json.Unmarshal(userSessionB, &us); err != nil {
+		return nil, err
+	}
+	return us, nil
+}
+
+func cacheSetSession(key string, session *models.Session) error {
+	sesb, err := json.Marshal(session)
+	if err != nil {
+		return err
+	}
+	memcache.Set(key, sesb)
+	// expire in 10 min
+	memcache.Expire(key, 10*60)
+	return nil
+}

handlers/middleware.go

@@ -0,0 +1,83 @@
+package handlers
+
+import (
+	"context"
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/base64"
+	"errors"
+	"golias/config"
+	"golias/pkg/cache"
+	"log/slog"
+	"net/http"
+)
+
+var (
+	cfg      config.Config
+	memcache cache.Cache
+)
+
+func GetSession(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		cookieName := "session_token"
+		sessionCookie, err := r.Cookie(cookieName)
+		if err != nil {
+			msg := "auth failed; failed to get session token from cookies"
+			slog.Debug(msg, "error", err)
+			next.ServeHTTP(w, r)
+			return
+		}
+		cookieValueB, err := base64.URLEncoding.
+			DecodeString(sessionCookie.Value)
+		if err != nil {
+			msg := "auth failed; failed to decode b64 cookie"
+			slog.Debug(msg, "error", err)
+			next.ServeHTTP(w, r)
+			return
+		}
+		cookieValue := string(cookieValueB)
+		if len(cookieValue) < sha256.Size {
+			slog.Warn("small cookie", "size", len(cookieValue))
+			next.ServeHTTP(w, r)
+			return
+		}
+		// Split apart the signature and original cookie value.
+		signature := cookieValue[:sha256.Size]
+		sessionToken := cookieValue[sha256.Size:]
+		//verify signature
+		mac := hmac.New(sha256.New, []byte(cfg.CookieSecret))
+		mac.Write([]byte(cookieName))
+		mac.Write([]byte(sessionToken))
+		expectedSignature := mac.Sum(nil)
+		if !hmac.Equal([]byte(signature), expectedSignature) {
+			slog.Debug("cookie with an invalid sign")
+			next.ServeHTTP(w, r)
+			return
+		}
+		userSession, err := cacheGetSession(sessionToken)
+		if err != nil {
+			msg := "auth failed; session does not exists"
+			err = errors.New(msg)
+			slog.Debug(msg, "error", err)
+			next.ServeHTTP(w, r)
+			return
+		}
+		if userSession.IsExpired() {
+			memcache.RemoveKey(sessionToken)
+			msg := "session is expired"
+			slog.Debug(msg, "error", err, "token", sessionToken)
+			next.ServeHTTP(w, r)
+			return
+		}
+		ctx := context.WithValue(r.Context(),
+			"username", userSession.Username)
+		if err := cacheSetSession(sessionToken,
+			userSession); err != nil {
+			msg := "failed to marshal user session"
+			slog.Warn(msg, "error", err)
+			next.ServeHTTP(w, r)
+			return
+		}
+		next.ServeHTTP(w, r.WithContext(ctx))
+	})
+}