tailscale/client/web/synology.go
Will Norris 0c3d343ea3 client/web: invert auth logic for synology and qnap
Add separate server methods for synology and qnap, and enforce
authentication and authorization checks before calling into the actual
serving handlers. This allows us to remove all of the auth logic from
those handlers, since all requests will already be authenticated by that
point.

Also simplify the Synology token redirect handler by using fetch.

Remove the SynologyUser from nodeData, since it was never used in the
frontend anyway.

Updates tailscale/corp#13775

Signed-off-by: Will Norris <will@tailscale.com>
2023-08-24 14:17:41 -07:00

77 lines
1.9 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
// synology.go contains handlers and logic, such as authentication,
// that is specific to running the web client on Synology.
package web
import (
"fmt"
"net/http"
"os/exec"
"strings"
"tailscale.com/util/groupmember"
)
// authorizeSynology authenticates the logged-in Synology user and verifies
// that they are authorized to use the web client. It returns true if the
// request was handled and no further processing is required.
func authorizeSynology(w http.ResponseWriter, r *http.Request) (handled bool) {
if synoTokenRedirect(w, r) {
return true
}
// authenticate the Synology user
cmd := exec.Command("/usr/syno/synoman/webman/modules/authenticate.cgi")
out, err := cmd.CombinedOutput()
if err != nil {
http.Error(w, fmt.Sprintf("auth: %v: %s", err, out), http.StatusUnauthorized)
return true
}
user := strings.TrimSpace(string(out))
// check if the user is in the administrators group
isAdmin, err := groupmember.IsMemberOfGroup("administrators", user)
if err != nil {
http.Error(w, err.Error(), http.StatusForbidden)
return true
}
if !isAdmin {
http.Error(w, "not a member of administrators group", http.StatusForbidden)
return true
}
return false
}
func synoTokenRedirect(w http.ResponseWriter, r *http.Request) bool {
if r.Header.Get("X-Syno-Token") != "" {
return false
}
if r.URL.Query().Get("SynoToken") != "" {
return false
}
if r.Method == "POST" && r.FormValue("SynoToken") != "" {
return false
}
// We need a SynoToken for authenticate.cgi.
// So we tell the client to get one.
_, _ = fmt.Fprint(w, synoTokenRedirectHTML)
return true
}
const synoTokenRedirectHTML = `<html>
Redirecting with session token...
<script>
fetch("/webman/login.cgi")
.then(r => r.json())
.then(data => {
u = new URL(window.location)
u.searchParams.set("SynoToken", data.SynoToken)
document.location = u
})
</script>
`