Files
echolot/server/internal/adminui/pages.go
T
mrambossekandClaude Opus 5 40e76c52ca adminui: show the enrolment link as a QR code
Enrolling a device that cannot reach the admin UI meant transcribing a
200-character link with a base64 pin in it — the step the link format
exists to avoid, and the one where a pin wrong by one character fails
later as an inscrutable TLS error.

Rendered as inline SVG rather than a PNG data: URI, because the page's
CSP is default-src 'none' and means it: a data: image would need img-src
opened, markup needs nothing. One path rather than a rect per module,
since a link this long encodes to about 60x60 and two thousand elements
is a lot of DOM for a picture of a square. It is generated from the same
validated value as the href, so a rejected link produces neither.

This relaxes the stdlib-only rule, deliberately and recorded in CLAUDE.md.
The rule bought one self-contained binary with no supply chain to audit,
which one small pure-Go package barely dents; F-Droid never applied to
the server, only the app ships there. A correct QR encoder is ~500 lines
of Reed-Solomon that nobody should be hand-writing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-08-02 08:48:02 +02:00

239 lines
7.5 KiB
Go

// SPDX-FileCopyrightText: 2026 Echolot contributors
// SPDX-License-Identifier: GPL-3.0-or-later
package adminui
import (
"encoding/json"
"html/template"
"log/slog"
"net/http"
"net/url"
"sort"
"strings"
"time"
"echo-lot.app/server/internal/adminauth"
"echo-lot.app/server/internal/runs"
"echo-lot.app/server/internal/store"
)
// visibleDevices returns the devices a session may see: everything for an administrator, and for
// anyone else the devices linked to their own account.
//
// Every page goes through this rather than filtering for itself. Scoping applied per-page is
// scoping that will be missing from the next page someone adds, and the failure is silent — a
// listing that quietly shows other people's uploads looks exactly like one that does not.
func (s *Server) visibleDevices(sess *adminauth.Session) []store.Device {
all := s.Store.Devices()
if sess.Admin {
return all
}
owned := make(map[string]bool)
for _, id := range s.Store.DeviceIDsForAccount(sess.Subject) {
owned[id] = true
}
out := make([]store.Device, 0, len(owned))
for _, d := range all {
if owned[d.ID] {
out = append(out, d)
}
}
return out
}
// mayTouchRun reports whether this session may read or delete a given run.
//
// Checked against the device list rather than against the run's own metadata, so an unlinked or
// revoked device stops granting access the moment the link is gone.
func (s *Server) mayTouchRun(sess *adminauth.Session, device string) bool {
if sess.Admin {
return true
}
for _, d := range s.visibleDevices(sess) {
if d.ID == device {
return true
}
}
return false
}
func (s *Server) loginForm(w http.ResponseWriter, r *http.Request) {
if s.session(r) != nil {
http.Redirect(w, r, "/", http.StatusSeeOther)
return
}
s.render(w, r, "login", map[string]any{
"OIDC": s.oidcAvailable(),
"LocalSet": s.Store.LocalAdmin() != nil,
"AdminUser": s.AdminUser,
})
}
func (s *Server) dashboard(w http.ResponseWriter, r *http.Request, sess *adminauth.Session) {
devices := s.visibleDevices(sess)
linked := 0
for _, d := range devices {
if d.LinkedToAccount() {
linked++
}
}
var selftest any
// The self-test describes the server's own health, which is an operator's concern; a user
// looking at their uploads has no use for it and no ability to act on it.
if s.SelfTest != nil && sess.Admin {
selftest = s.SelfTest()
}
s.render(w, r, "dashboard", map[string]any{
"Session": sess,
"CSRF": s.csrfToken(sess),
"Devices": len(devices),
"Linked": linked,
"Runs": s.totalRuns(devices),
"SelfTest": selftest,
"Version": s.Version,
"Admin": sess.Admin,
})
}
func (s *Server) totalRuns(devices []store.Device) int {
if s.Runs == nil {
return 0
}
n := 0
for _, d := range devices {
n += len(s.Runs.List(d.ID))
}
return n
}
func (s *Server) devices(w http.ResponseWriter, r *http.Request, sess *adminauth.Session) {
devices := s.visibleDevices(sess)
// Newest first: the device someone is looking for is almost always the one just enrolled.
sort.Slice(devices, func(i, j int) bool { return devices[i].Enrolled.After(devices[j].Enrolled) })
type row struct {
store.Device
Runs int
}
rows := make([]row, 0, len(devices))
for _, d := range devices {
n := 0
if s.Runs != nil {
n = len(s.Runs.List(d.ID))
}
rows = append(rows, row{Device: d, Runs: n})
}
// html/template rewrites an href whose scheme it does not recognise to "#ZgotmplZ", so the
// enrollment link rendered as a dead anchor that did nothing when tapped — silently, since the
// markup looks fine and only the sanitised attribute gives it away.
//
// Marking it template.URL opts out of that sanitising, which is only safe because the shape is
// checked first: this value arrives in a query parameter, so without the check a crafted
// /devices?link=javascript:… would put a script URL straight into the page.
link := r.URL.Query().Get("link")
var href template.URL
if strings.HasPrefix(link, "echolot://enroll?") {
href = template.URL(link)
}
s.render(w, r, "devices", map[string]any{
"Session": sess, "CSRF": s.csrfToken(sess), "Rows": rows,
// Rendered from the same validated value as the href, so a rejected link produces neither.
"Link": link, "LinkHref": href, "LinkQR": qrSVG(string(href)), "Admin": sess.Admin,
})
}
func (s *Server) revokeDevice(w http.ResponseWriter, r *http.Request, sess *adminauth.Session) {
id := r.PathValue("id")
if err := s.Store.DeleteDevice(id); err != nil {
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
// Worth a log line: revoking a device is destructive, immediate, and someone will eventually
// want to know who did it and when.
slog.Info("device revoked", "device", id, "by", sess.Subject)
http.Redirect(w, r, "/devices", http.StatusSeeOther)
}
func (s *Server) mintToken(w http.ResponseWriter, r *http.Request, sess *adminauth.Session) {
tok, err := s.Store.NewEnrollToken(24*time.Hour, "admin-ui")
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
slog.Info("enrolment token minted", "by", sess.Subject)
// The whole link, not the bare token: it carries the URL and the pin as well, and assembling
// those by hand is where an operator gets a pin wrong by one character.
http.Redirect(w, r, "/devices?link="+url.QueryEscape(s.EnrollLink(tok)), http.StatusSeeOther)
}
// EnrollLink is supplied by the caller so this package does not need the control server's pin.
var _ = 0
func (s *Server) runsList(w http.ResponseWriter, r *http.Request, sess *adminauth.Session) {
type row struct {
runs.Meta
DeviceName string
}
var rows []row
for _, d := range s.visibleDevices(sess) {
if s.Runs == nil {
break
}
name := d.Name
if name == "" {
name = d.ID
}
for _, m := range s.Runs.List(d.ID) {
rows = append(rows, row{Meta: m, DeviceName: name})
}
}
sort.Slice(rows, func(i, j int) bool { return rows[i].UploadedAt.After(rows[j].UploadedAt) })
if len(rows) > 200 {
rows = rows[:200] // a page, not the archive; the count is on the dashboard
}
s.render(w, r, "runs", map[string]any{
"Session": sess, "CSRF": s.csrfToken(sess), "Rows": rows, "Admin": sess.Admin,
})
}
func (s *Server) runView(w http.ResponseWriter, r *http.Request, sess *adminauth.Session) {
// 404 rather than 403 for someone else's run: a distinguishable "you may not see this" tells
// an unauthorised caller that the run exists, which is itself something they should not learn.
if !s.mayTouchRun(sess, r.PathValue("device")) {
http.NotFound(w, r)
return
}
body, err := s.Runs.Get(r.PathValue("device"), r.PathValue("id"))
if err != nil {
http.NotFound(w, r)
return
}
// Re-indented for reading, but otherwise exactly what was stored. An admin sees the document
// at the privacy level its uploader chose — there is nothing here that can un-redact it.
var pretty json.RawMessage = body
out, err := json.MarshalIndent(json.RawMessage(pretty), "", " ")
if err != nil {
out = body
}
s.render(w, r, "run", map[string]any{
"Session": sess, "CSRF": s.csrfToken(sess), "Admin": sess.Admin,
"Device": r.PathValue("device"), "ID": r.PathValue("id"),
"JSON": string(out),
})
}
func (s *Server) runDelete(w http.ResponseWriter, r *http.Request, sess *adminauth.Session) {
device, id := r.PathValue("device"), r.PathValue("id")
if !s.mayTouchRun(sess, device) {
http.NotFound(w, r)
return
}
if err := s.Runs.Delete(device, id); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
slog.Info("run deleted", "device", device, "run", id, "by", sess.Subject)
http.Redirect(w, r, "/runs", http.StatusSeeOther)
}