GoToSocial/internal/middleware/session.go

96 lines
3.2 KiB
Go

/*
GoToSocial
Copyright (C) 2021-2023 GoToSocial Authors admin@gotosocial.org
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package middleware
import (
"fmt"
"net/http"
"net/url"
"strings"
"github.com/gin-contrib/sessions"
"github.com/gin-contrib/sessions/memstore"
"github.com/gin-gonic/gin"
"github.com/superseriousbusiness/gotosocial/internal/config"
"github.com/superseriousbusiness/gotosocial/internal/log"
"golang.org/x/net/idna"
)
// SessionOptions returns the standard set of options to use for each session.
func SessionOptions() sessions.Options {
var samesite http.SameSite
switch strings.TrimSpace(strings.ToLower(config.GetAdvancedCookiesSamesite())) {
case "lax":
samesite = http.SameSiteLaxMode
case "strict":
samesite = http.SameSiteStrictMode
default:
log.Warnf("%s set to %s which is not recognized, defaulting to 'lax'", config.AdvancedCookiesSamesiteFlag(), config.GetAdvancedCookiesSamesite())
samesite = http.SameSiteLaxMode
}
return sessions.Options{
Path: "/",
Domain: config.GetHost(),
// 2 minutes
MaxAge: 120,
// only set secure over https
Secure: config.GetProtocol() == "https",
// forbid javascript from inspecting cookie
HttpOnly: true,
// https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-cookie-same-site-00#section-4.1.1
SameSite: samesite,
}
}
// SessionName is a utility function that derives an appropriate session name from the hostname.
func SessionName() (string, error) {
// parse the protocol + host
protocol := config.GetProtocol()
host := config.GetHost()
u, err := url.Parse(fmt.Sprintf("%s://%s", protocol, host))
if err != nil {
return "", err
}
// take the hostname without any port attached
strippedHostname := u.Hostname()
if strippedHostname == "" {
return "", fmt.Errorf("could not derive hostname without port from %s://%s", protocol, host)
}
// make sure IDNs are converted to punycode or the cookie library breaks:
// see https://en.wikipedia.org/wiki/Punycode
punyHostname, err := idna.New().ToASCII(strippedHostname)
if err != nil {
return "", fmt.Errorf("could not convert %s to punycode: %s", strippedHostname, err)
}
return fmt.Sprintf("gotosocial-%s", punyHostname), nil
}
// Session returns a new gin middleware that implements session cookies using the given
// sessionName, authentication key, and encryption key. Session name can be derived from the
// SessionName utility function in this package.
func Session(sessionName string, auth []byte, crypt []byte) gin.HandlerFunc {
store := memstore.NewStore(auth, crypt)
store.Options(SessionOptions())
return sessions.Sessions(sessionName, store)
}