Initial commit

cpone-dashboard/menu/auth/session.go

@@ -0,0 +1,124 @@
+package auth
+
+import (
+	"context"
+	"crypto/hmac"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/hex"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+)
+
+const cookieName = "cpone_session"
+const projectCookieName = "cpone_project_mcu_id"
+
+type ctxKey string
+
+const userCtxKey ctxKey = "username"
+
+// Username returns the logged-in username from the request context.
+func Username(r *http.Request) string {
+	v, _ := r.Context().Value(userCtxKey).(string)
+	return v
+}
+
+func setContext(r *http.Request, username string) *http.Request {
+	return r.WithContext(context.WithValue(r.Context(), userCtxKey, username))
+}
+
+func SetSession(w http.ResponseWriter, username, secret string) {
+	val := encode(username) + "." + sign(username, secret)
+	http.SetCookie(w, &http.Cookie{
+		Name:     cookieName,
+		Value:    val,
+		Path:     "/",
+		HttpOnly: true,
+		SameSite: http.SameSiteLaxMode,
+		Expires:  time.Now().Add(24 * time.Hour),
+	})
+}
+
+func ClearSession(w http.ResponseWriter) {
+	http.SetCookie(w, &http.Cookie{
+		Name:   cookieName,
+		Value:  "",
+		Path:   "/",
+		MaxAge: -1,
+	})
+}
+
+func SetSelectedProject(w http.ResponseWriter, mcuID int) {
+	http.SetCookie(w, &http.Cookie{
+		Name:     projectCookieName,
+		Value:    strconv.Itoa(mcuID),
+		Path:     "/",
+		HttpOnly: true,
+		SameSite: http.SameSiteLaxMode,
+		Expires:  time.Now().Add(7 * 24 * time.Hour),
+	})
+}
+
+func ClearSelectedProject(w http.ResponseWriter) {
+	http.SetCookie(w, &http.Cookie{
+		Name:   projectCookieName,
+		Value:  "",
+		Path:   "/",
+		MaxAge: -1,
+	})
+}
+
+func SelectedProjectID(r *http.Request) int {
+	c, err := r.Cookie(projectCookieName)
+	if err != nil {
+		return 0
+	}
+	id, err := strconv.Atoi(strings.TrimSpace(c.Value))
+	if err != nil {
+		return 0
+	}
+	return id
+}
+
+func getSession(r *http.Request, secret string) string {
+	c, err := r.Cookie(cookieName)
+	if err != nil {
+		return ""
+	}
+	parts := strings.SplitN(c.Value, ".", 2)
+	if len(parts) != 2 {
+		return ""
+	}
+	username, err := decode(parts[0])
+	if err != nil || username == "" {
+		return ""
+	}
+	if !hmac.Equal([]byte(sign(username, secret)), []byte(parts[1])) {
+		return ""
+	}
+	return username
+}
+
+func newUUID() string {
+	b := make([]byte, 16)
+	rand.Read(b)
+	return hex.EncodeToString(b)
+}
+
+func sign(username, secret string) string {
+	mac := hmac.New(sha256.New, []byte(secret))
+	mac.Write([]byte(username))
+	return base64.RawURLEncoding.EncodeToString(mac.Sum(nil))
+}
+
+func encode(s string) string {
+	return base64.RawURLEncoding.EncodeToString([]byte(s))
+}
+
+func decode(s string) (string, error) {
+	b, err := base64.RawURLEncoding.DecodeString(s)
+	return string(b), err
+}