fix(security): UPnP opt-in, bounded SSE reader, signed self-update

Phase 2 security audit follow-up. Three independent hardenings against
the unauthenticated daemon surface, the long-lived agent SSE stream
and the self-update channel.

UPnP is now opt-in. The stream port + /hls endpoints have no auth, so
publishing them on the WAN via the gateway was a default that exposed
active downloads to anyone scanning the operator's external IP. New
config downloads.enable_upnp (default false) gates the mapping; LAN
and Tailscale clients continue to work unchanged. A startup log makes
the new default visible.

The agent SSE reader now uses a bounded bufio.Scanner instead of an
unbounded ReadString. A hostile or buggy server can no longer grow
daemon memory by streaming a single line forever or by emitting
unbounded data: continuation lines — both are capped at 256 KiB and
1 MiB respectively, and an error is surfaced so SignalLoop reconnects.

Self-update now verifies an ed25519 signature over checksums.txt when
the binary was built with a release public key embedded (injected via
goreleaser ldflags from RELEASE_SIGNING_PUBKEY). The companion
scripts/sign-checksums runs in the release workflow when both the
public-key variable and the private-key secret are present, uploading
checksums.txt.sig next to the existing checksums file. Builds without
the embedded key continue to update with SHA256-only verification; a
--allow-unsigned flag is provided so users on a signed build can
still install pre-signing releases or recover from an accidental
unsigned release.

A new scripts/gen-release-key helper documents the one-time keypair
generation procedure required before flipping signing on.
This commit is contained in:
Deivid Soto 2026-05-15 17:29:22 +02:00
parent c148cb8ce7
commit 433e375def
17 changed files with 551 additions and 32 deletions

View file

@ -13,6 +13,7 @@ import (
func newSelfUpdateCmd() *cobra.Command {
var force bool
var allowUnsigned bool
cmd := &cobra.Command{
Use: "self-update",
@ -26,18 +27,20 @@ If the daemon is running, it is automatically restarted so the new
version is loaded into memory (otherwise heartbeat would keep
reporting the old version until a manual restart).`,
Example: ` unarr self-update
unarr self-update --force`,
unarr self-update --force
unarr self-update --allow-unsigned # accept releases missing checksums.txt.sig`,
RunE: func(cmd *cobra.Command, args []string) error {
return runSelfUpdate(force)
return runSelfUpdate(force, allowUnsigned)
},
}
cmd.Flags().BoolVarP(&force, "force", "f", false, "reinstall even if already up to date")
cmd.Flags().BoolVar(&allowUnsigned, "allow-unsigned", false, "continue with SHA256-only verification when checksums.txt.sig is missing")
return cmd
}
func runSelfUpdate(force bool) error {
func runSelfUpdate(force, allowUnsigned bool) error {
bold := color.New(color.Bold)
green := color.New(color.FgGreen)
yellow := color.New(color.FgYellow)
@ -74,6 +77,7 @@ func runSelfUpdate(force bool) error {
upgrader := &upgrade.Upgrader{
CurrentVersion: currentClean,
AllowUnsigned: allowUnsigned,
OnProgress: func(msg string) {
fmt.Printf(" %s\n", msg)
},